diff options
Diffstat (limited to 'drivers/spi/spi-pl022.c')
| -rw-r--r-- | drivers/spi/spi-pl022.c | 2430 |
1 files changed, 2430 insertions, 0 deletions
diff --git a/drivers/spi/spi-pl022.c b/drivers/spi/spi-pl022.c new file mode 100644 index 00000000000..66d2ae21e78 --- /dev/null +++ b/drivers/spi/spi-pl022.c @@ -0,0 +1,2430 @@ +/* + * A driver for the ARM PL022 PrimeCell SSP/SPI bus master. + * + * Copyright (C) 2008-2012 ST-Ericsson AB + * Copyright (C) 2006 STMicroelectronics Pvt. Ltd. + * + * Author: Linus Walleij <linus.walleij@stericsson.com> + * + * Initial version inspired by: + * linux-2.6.17-rc3-mm1/drivers/spi/pxa2xx_spi.c + * Initial adoption to PL022 by: + * Sachin Verma <sachin.verma@st.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/init.h> +#include <linux/module.h> +#include <linux/device.h> +#include <linux/ioport.h> +#include <linux/errno.h> +#include <linux/interrupt.h> +#include <linux/spi/spi.h> +#include <linux/delay.h> +#include <linux/clk.h> +#include <linux/err.h> +#include <linux/amba/bus.h> +#include <linux/amba/pl022.h> +#include <linux/io.h> +#include <linux/slab.h> +#include <linux/dmaengine.h> +#include <linux/dma-mapping.h> +#include <linux/scatterlist.h> +#include <linux/pm_runtime.h> +#include <linux/gpio.h> +#include <linux/of_gpio.h> +#include <linux/pinctrl/consumer.h> + +/* + * This macro is used to define some register default values. + * reg is masked with mask, the OR:ed with an (again masked) + * val shifted sb steps to the left. + */ +#define SSP_WRITE_BITS(reg, val, mask, sb) \ + ((reg) = (((reg) & ~(mask)) | (((val)<<(sb)) & (mask)))) + +/* + * This macro is also used to define some default values. + * It will just shift val by sb steps to the left and mask + * the result with mask. + */ +#define GEN_MASK_BITS(val, mask, sb) \ + (((val)<<(sb)) & (mask)) + +#define DRIVE_TX 0 +#define DO_NOT_DRIVE_TX 1 + +#define DO_NOT_QUEUE_DMA 0 +#define QUEUE_DMA 1 + +#define RX_TRANSFER 1 +#define TX_TRANSFER 2 + +/* + * Macros to access SSP Registers with their offsets + */ +#define SSP_CR0(r) (r + 0x000) +#define SSP_CR1(r) (r + 0x004) +#define SSP_DR(r) (r + 0x008) +#define SSP_SR(r) (r + 0x00C) +#define SSP_CPSR(r) (r + 0x010) +#define SSP_IMSC(r) (r + 0x014) +#define SSP_RIS(r) (r + 0x018) +#define SSP_MIS(r) (r + 0x01C) +#define SSP_ICR(r) (r + 0x020) +#define SSP_DMACR(r) (r + 0x024) +#define SSP_ITCR(r) (r + 0x080) +#define SSP_ITIP(r) (r + 0x084) +#define SSP_ITOP(r) (r + 0x088) +#define SSP_TDR(r) (r + 0x08C) + +#define SSP_PID0(r) (r + 0xFE0) +#define SSP_PID1(r) (r + 0xFE4) +#define SSP_PID2(r) (r + 0xFE8) +#define SSP_PID3(r) (r + 0xFEC) + +#define SSP_CID0(r) (r + 0xFF0) +#define SSP_CID1(r) (r + 0xFF4) +#define SSP_CID2(r) (r + 0xFF8) +#define SSP_CID3(r) (r + 0xFFC) + +/* + * SSP Control Register 0 - SSP_CR0 + */ +#define SSP_CR0_MASK_DSS (0x0FUL << 0) +#define SSP_CR0_MASK_FRF (0x3UL << 4) +#define SSP_CR0_MASK_SPO (0x1UL << 6) +#define SSP_CR0_MASK_SPH (0x1UL << 7) +#define SSP_CR0_MASK_SCR (0xFFUL << 8) + +/* + * The ST version of this block moves som bits + * in SSP_CR0 and extends it to 32 bits + */ +#define SSP_CR0_MASK_DSS_ST (0x1FUL << 0) +#define SSP_CR0_MASK_HALFDUP_ST (0x1UL << 5) +#define SSP_CR0_MASK_CSS_ST (0x1FUL << 16) +#define SSP_CR0_MASK_FRF_ST (0x3UL << 21) + +/* + * SSP Control Register 0 - SSP_CR1 + */ +#define SSP_CR1_MASK_LBM (0x1UL << 0) +#define SSP_CR1_MASK_SSE (0x1UL << 1) +#define SSP_CR1_MASK_MS (0x1UL << 2) +#define SSP_CR1_MASK_SOD (0x1UL << 3) + +/* + * The ST version of this block adds some bits + * in SSP_CR1 + */ +#define SSP_CR1_MASK_RENDN_ST (0x1UL << 4) +#define SSP_CR1_MASK_TENDN_ST (0x1UL << 5) +#define SSP_CR1_MASK_MWAIT_ST (0x1UL << 6) +#define SSP_CR1_MASK_RXIFLSEL_ST (0x7UL << 7) +#define SSP_CR1_MASK_TXIFLSEL_ST (0x7UL << 10) +/* This one is only in the PL023 variant */ +#define SSP_CR1_MASK_FBCLKDEL_ST (0x7UL << 13) + +/* + * SSP Status Register - SSP_SR + */ +#define SSP_SR_MASK_TFE (0x1UL << 0) /* Transmit FIFO empty */ +#define SSP_SR_MASK_TNF (0x1UL << 1) /* Transmit FIFO not full */ +#define SSP_SR_MASK_RNE (0x1UL << 2) /* Receive FIFO not empty */ +#define SSP_SR_MASK_RFF (0x1UL << 3) /* Receive FIFO full */ +#define SSP_SR_MASK_BSY (0x1UL << 4) /* Busy Flag */ + +/* + * SSP Clock Prescale Register - SSP_CPSR + */ +#define SSP_CPSR_MASK_CPSDVSR (0xFFUL << 0) + +/* + * SSP Interrupt Mask Set/Clear Register - SSP_IMSC + */ +#define SSP_IMSC_MASK_RORIM (0x1UL << 0) /* Receive Overrun Interrupt mask */ +#define SSP_IMSC_MASK_RTIM (0x1UL << 1) /* Receive timeout Interrupt mask */ +#define SSP_IMSC_MASK_RXIM (0x1UL << 2) /* Receive FIFO Interrupt mask */ +#define SSP_IMSC_MASK_TXIM (0x1UL << 3) /* Transmit FIFO Interrupt mask */ + +/* + * SSP Raw Interrupt Status Register - SSP_RIS + */ +/* Receive Overrun Raw Interrupt status */ +#define SSP_RIS_MASK_RORRIS (0x1UL << 0) +/* Receive Timeout Raw Interrupt status */ +#define SSP_RIS_MASK_RTRIS (0x1UL << 1) +/* Receive FIFO Raw Interrupt status */ +#define SSP_RIS_MASK_RXRIS (0x1UL << 2) +/* Transmit FIFO Raw Interrupt status */ +#define SSP_RIS_MASK_TXRIS (0x1UL << 3) + +/* + * SSP Masked Interrupt Status Register - SSP_MIS + */ +/* Receive Overrun Masked Interrupt status */ +#define SSP_MIS_MASK_RORMIS (0x1UL << 0) +/* Receive Timeout Masked Interrupt status */ +#define SSP_MIS_MASK_RTMIS (0x1UL << 1) +/* Receive FIFO Masked Interrupt status */ +#define SSP_MIS_MASK_RXMIS (0x1UL << 2) +/* Transmit FIFO Masked Interrupt status */ +#define SSP_MIS_MASK_TXMIS (0x1UL << 3) + +/* + * SSP Interrupt Clear Register - SSP_ICR + */ +/* Receive Overrun Raw Clear Interrupt bit */ +#define SSP_ICR_MASK_RORIC (0x1UL << 0) +/* Receive Timeout Clear Interrupt bit */ +#define SSP_ICR_MASK_RTIC (0x1UL << 1) + +/* + * SSP DMA Control Register - SSP_DMACR + */ +/* Receive DMA Enable bit */ +#define SSP_DMACR_MASK_RXDMAE (0x1UL << 0) +/* Transmit DMA Enable bit */ +#define SSP_DMACR_MASK_TXDMAE (0x1UL << 1) + +/* + * SSP Integration Test control Register - SSP_ITCR + */ +#define SSP_ITCR_MASK_ITEN (0x1UL << 0) +#define SSP_ITCR_MASK_TESTFIFO (0x1UL << 1) + +/* + * SSP Integration Test Input Register - SSP_ITIP + */ +#define ITIP_MASK_SSPRXD (0x1UL << 0) +#define ITIP_MASK_SSPFSSIN (0x1UL << 1) +#define ITIP_MASK_SSPCLKIN (0x1UL << 2) +#define ITIP_MASK_RXDMAC (0x1UL << 3) +#define ITIP_MASK_TXDMAC (0x1UL << 4) +#define ITIP_MASK_SSPTXDIN (0x1UL << 5) + +/* + * SSP Integration Test output Register - SSP_ITOP + */ +#define ITOP_MASK_SSPTXD (0x1UL << 0) +#define ITOP_MASK_SSPFSSOUT (0x1UL << 1) +#define ITOP_MASK_SSPCLKOUT (0x1UL << 2) +#define ITOP_MASK_SSPOEn (0x1UL << 3) +#define ITOP_MASK_SSPCTLOEn (0x1UL << 4) +#define ITOP_MASK_RORINTR (0x1UL << 5) +#define ITOP_MASK_RTINTR (0x1UL << 6) +#define ITOP_MASK_RXINTR (0x1UL << 7) +#define ITOP_MASK_TXINTR (0x1UL << 8) +#define ITOP_MASK_INTR (0x1UL << 9) +#define ITOP_MASK_RXDMABREQ (0x1UL << 10) +#define ITOP_MASK_RXDMASREQ (0x1UL << 11) +#define ITOP_MASK_TXDMABREQ (0x1UL << 12) +#define ITOP_MASK_TXDMASREQ (0x1UL << 13) + +/* + * SSP Test Data Register - SSP_TDR + */ +#define TDR_MASK_TESTDATA (0xFFFFFFFF) + +/* + * Message State + * we use the spi_message.state (void *) pointer to + * hold a single state value, that's why all this + * (void *) casting is done here. + */ +#define STATE_START ((void *) 0) +#define STATE_RUNNING ((void *) 1) +#define STATE_DONE ((void *) 2) +#define STATE_ERROR ((void *) -1) + +/* + * SSP State - Whether Enabled or Disabled + */ +#define SSP_DISABLED (0) +#define SSP_ENABLED (1) + +/* + * SSP DMA State - Whether DMA Enabled or Disabled + */ +#define SSP_DMA_DISABLED (0) +#define SSP_DMA_ENABLED (1) + +/* + * SSP Clock Defaults + */ +#define SSP_DEFAULT_CLKRATE 0x2 +#define SSP_DEFAULT_PRESCALE 0x40 + +/* + * SSP Clock Parameter ranges + */ +#define CPSDVR_MIN 0x02 +#define CPSDVR_MAX 0xFE +#define SCR_MIN 0x00 +#define SCR_MAX 0xFF + +/* + * SSP Interrupt related Macros + */ +#define DEFAULT_SSP_REG_IMSC 0x0UL +#define DISABLE_ALL_INTERRUPTS DEFAULT_SSP_REG_IMSC +#define ENABLE_ALL_INTERRUPTS (~DEFAULT_SSP_REG_IMSC) + +#define CLEAR_ALL_INTERRUPTS 0x3 + +#define SPI_POLLING_TIMEOUT 1000 + +/* + * The type of reading going on on this chip + */ +enum ssp_reading { + READING_NULL, + READING_U8, + READING_U16, + READING_U32 +}; + +/** + * The type of writing going on on this chip + */ +enum ssp_writing { + WRITING_NULL, + WRITING_U8, + WRITING_U16, + WRITING_U32 +}; + +/** + * struct vendor_data - vendor-specific config parameters + * for PL022 derivates + * @fifodepth: depth of FIFOs (both) + * @max_bpw: maximum number of bits per word + * @unidir: supports unidirection transfers + * @extended_cr: 32 bit wide control register 0 with extra + * features and extra features in CR1 as found in the ST variants + * @pl023: supports a subset of the ST extensions called "PL023" + */ +struct vendor_data { + int fifodepth; + int max_bpw; + bool unidir; + bool extended_cr; + bool pl023; + bool loopback; +}; + +/** + * struct pl022 - This is the private SSP driver data structure + * @adev: AMBA device model hookup + * @vendor: vendor data for the IP block + * @phybase: the physical memory where the SSP device resides + * @virtbase: the virtual memory where the SSP is mapped + * @clk: outgoing clock "SPICLK" for the SPI bus + * @master: SPI framework hookup + * @master_info: controller-specific data from machine setup + * @kworker: thread struct for message pump + * @kworker_task: pointer to task for message pump kworker thread + * @pump_messages: work struct for scheduling work to the message pump + * @queue_lock: spinlock to syncronise access to message queue + * @queue: message queue + * @busy: message pump is busy + * @running: message pump is running + * @pump_transfers: Tasklet used in Interrupt Transfer mode + * @cur_msg: Pointer to current spi_message being processed + * @cur_transfer: Pointer to current spi_transfer + * @cur_chip: pointer to current clients chip(assigned from controller_state) + * @next_msg_cs_active: the next message in the queue has been examined + * and it was found that it uses the same chip select as the previous + * message, so we left it active after the previous transfer, and it's + * active already. + * @tx: current position in TX buffer to be read + * @tx_end: end position in TX buffer to be read + * @rx: current position in RX buffer to be written + * @rx_end: end position in RX buffer to be written + * @read: the type of read currently going on + * @write: the type of write currently going on + * @exp_fifo_level: expected FIFO level + * @dma_rx_channel: optional channel for RX DMA + * @dma_tx_channel: optional channel for TX DMA + * @sgt_rx: scattertable for the RX transfer + * @sgt_tx: scattertable for the TX transfer + * @dummypage: a dummy page used for driving data on the bus with DMA + * @cur_cs: current chip select (gpio) + * @chipselects: list of chipselects (gpios) + */ +struct pl022 { + struct amba_device *adev; + struct vendor_data *vendor; + resource_size_t phybase; + void __iomem *virtbase; + struct clk *clk; + struct spi_master *master; + struct pl022_ssp_controller *master_info; + /* Message per-transfer pump */ + struct tasklet_struct pump_transfers; + struct spi_message *cur_msg; + struct spi_transfer *cur_transfer; + struct chip_data *cur_chip; + bool next_msg_cs_active; + void *tx; + void *tx_end; + void *rx; + void *rx_end; + enum ssp_reading read; + enum ssp_writing write; + u32 exp_fifo_level; + enum ssp_rx_level_trig rx_lev_trig; + enum ssp_tx_level_trig tx_lev_trig; + /* DMA settings */ +#ifdef CONFIG_DMA_ENGINE + struct dma_chan *dma_rx_channel; + struct dma_chan *dma_tx_channel; + struct sg_table sgt_rx; + struct sg_table sgt_tx; + char *dummypage; + bool dma_running; +#endif + int cur_cs; + int *chipselects; +}; + +/** + * struct chip_data - To maintain runtime state of SSP for each client chip + * @cr0: Value of control register CR0 of SSP - on later ST variants this + * register is 32 bits wide rather than just 16 + * @cr1: Value of control register CR1 of SSP + * @dmacr: Value of DMA control Register of SSP + * @cpsr: Value of Clock prescale register + * @n_bytes: how many bytes(power of 2) reqd for a given data width of client + * @enable_dma: Whether to enable DMA or not + * @read: function ptr to be used to read when doing xfer for this chip + * @write: function ptr to be used to write when doing xfer for this chip + * @cs_control: chip select callback provided by chip + * @xfer_type: polling/interrupt/DMA + * + * Runtime state of the SSP controller, maintained per chip, + * This would be set according to the current message that would be served + */ +struct chip_data { + u32 cr0; + u16 cr1; + u16 dmacr; + u16 cpsr; + u8 n_bytes; + bool enable_dma; + enum ssp_reading read; + enum ssp_writing write; + void (*cs_control) (u32 command); + int xfer_type; +}; + +/** + * null_cs_control - Dummy chip select function + * @command: select/delect the chip + * + * If no chip select function is provided by client this is used as dummy + * chip select + */ +static void null_cs_control(u32 command) +{ + pr_debug("pl022: dummy chip select control, CS=0x%x\n", command); +} + +static void pl022_cs_control(struct pl022 *pl022, u32 command) +{ + if (gpio_is_valid(pl022->cur_cs)) + gpio_set_value(pl022->cur_cs, command); + else + pl022->cur_chip->cs_control(command); +} + +/** + * giveback - current spi_message is over, schedule next message and call + * callback of this message. Assumes that caller already + * set message->status; dma and pio irqs are blocked + * @pl022: SSP driver private data structure + */ +static void giveback(struct pl022 *pl022) +{ + struct spi_transfer *last_transfer; + pl022->next_msg_cs_active = false; + + last_transfer = list_last_entry(&pl022->cur_msg->transfers, + struct spi_transfer, transfer_list); + + /* Delay if requested before any change in chip select */ + if (last_transfer->delay_usecs) + /* + * FIXME: This runs in interrupt context. + * Is this really smart? + */ + udelay(last_transfer->delay_usecs); + + if (!last_transfer->cs_change) { + struct spi_message *next_msg; + + /* + * cs_change was not set. We can keep the chip select + * enabled if there is message in the queue and it is + * for the same spi device. + * + * We cannot postpone this until pump_messages, because + * after calling msg->complete (below) the driver that + * sent the current message could be unloaded, which + * could invalidate the cs_control() callback... + */ + /* get a pointer to the next message, if any */ + next_msg = spi_get_next_queued_message(pl022->master); + + /* + * see if the next and current messages point + * to the same spi device. + */ + if (next_msg && next_msg->spi != pl022->cur_msg->spi) + next_msg = NULL; + if (!next_msg || pl022->cur_msg->state == STATE_ERROR) + pl022_cs_control(pl022, SSP_CHIP_DESELECT); + else + pl022->next_msg_cs_active = true; + + } + + pl022->cur_msg = NULL; + pl022->cur_transfer = NULL; + pl022->cur_chip = NULL; + spi_finalize_current_message(pl022->master); + + /* disable the SPI/SSP operation */ + writew((readw(SSP_CR1(pl022->virtbase)) & + (~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase)); + +} + +/** + * flush - flush the FIFO to reach a clean state + * @pl022: SSP driver private data structure + */ +static int flush(struct pl022 *pl022) +{ + unsigned long limit = loops_per_jiffy << 1; + + dev_dbg(&pl022->adev->dev, "flush\n"); + do { + while (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE) + readw(SSP_DR(pl022->virtbase)); + } while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_BSY) && limit--); + + pl022->exp_fifo_level = 0; + + return limit; +} + +/** + * restore_state - Load configuration of current chip + * @pl022: SSP driver private data structure + */ +static void restore_state(struct pl022 *pl022) +{ + struct chip_data *chip = pl022->cur_chip; + + if (pl022->vendor->extended_cr) + writel(chip->cr0, SSP_CR0(pl022->virtbase)); + else + writew(chip->cr0, SSP_CR0(pl022->virtbase)); + writew(chip->cr1, SSP_CR1(pl022->virtbase)); + writew(chip->dmacr, SSP_DMACR(pl022->virtbase)); + writew(chip->cpsr, SSP_CPSR(pl022->virtbase)); + writew(DISABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase)); + writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase)); +} + +/* + * Default SSP Register Values + */ +#define DEFAULT_SSP_REG_CR0 ( \ + GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS, 0) | \ + GEN_MASK_BITS(SSP_INTERFACE_MOTOROLA_SPI, SSP_CR0_MASK_FRF, 4) | \ + GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \ + GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \ + GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) \ +) + +/* ST versions have slightly different bit layout */ +#define DEFAULT_SSP_REG_CR0_ST ( \ + GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS_ST, 0) | \ + GEN_MASK_BITS(SSP_MICROWIRE_CHANNEL_FULL_DUPLEX, SSP_CR0_MASK_HALFDUP_ST, 5) | \ + GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \ + GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \ + GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) | \ + GEN_MASK_BITS(SSP_BITS_8, SSP_CR0_MASK_CSS_ST, 16) | \ + GEN_MASK_BITS(SSP_INTERFACE_MOTOROLA_SPI, SSP_CR0_MASK_FRF_ST, 21) \ +) + +/* The PL023 version is slightly different again */ +#define DEFAULT_SSP_REG_CR0_ST_PL023 ( \ + GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS_ST, 0) | \ + GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \ + GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \ + GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) \ +) + +#define DEFAULT_SSP_REG_CR1 ( \ + GEN_MASK_BITS(LOOPBACK_DISABLED, SSP_CR1_MASK_LBM, 0) | \ + GEN_MASK_BITS(SSP_DISABLED, SSP_CR1_MASK_SSE, 1) | \ + GEN_MASK_BITS(SSP_MASTER, SSP_CR1_MASK_MS, 2) | \ + GEN_MASK_BITS(DO_NOT_DRIVE_TX, SSP_CR1_MASK_SOD, 3) \ +) + +/* ST versions extend this register to use all 16 bits */ +#define DEFAULT_SSP_REG_CR1_ST ( \ + DEFAULT_SSP_REG_CR1 | \ + GEN_MASK_BITS(SSP_RX_MSB, SSP_CR1_MASK_RENDN_ST, 4) | \ + GEN_MASK_BITS(SSP_TX_MSB, SSP_CR1_MASK_TENDN_ST, 5) | \ + GEN_MASK_BITS(SSP_MWIRE_WAIT_ZERO, SSP_CR1_MASK_MWAIT_ST, 6) |\ + GEN_MASK_BITS(SSP_RX_1_OR_MORE_ELEM, SSP_CR1_MASK_RXIFLSEL_ST, 7) | \ + GEN_MASK_BITS(SSP_TX_1_OR_MORE_EMPTY_LOC, SSP_CR1_MASK_TXIFLSEL_ST, 10) \ +) + +/* + * The PL023 variant has further differences: no loopback mode, no microwire + * support, and a new clock feedback delay setting. + */ +#define DEFAULT_SSP_REG_CR1_ST_PL023 ( \ + GEN_MASK_BITS(SSP_DISABLED, SSP_CR1_MASK_SSE, 1) | \ + GEN_MASK_BITS(SSP_MASTER, SSP_CR1_MASK_MS, 2) | \ + GEN_MASK_BITS(DO_NOT_DRIVE_TX, SSP_CR1_MASK_SOD, 3) | \ + GEN_MASK_BITS(SSP_RX_MSB, SSP_CR1_MASK_RENDN_ST, 4) | \ + GEN_MASK_BITS(SSP_TX_MSB, SSP_CR1_MASK_TENDN_ST, 5) | \ + GEN_MASK_BITS(SSP_RX_1_OR_MORE_ELEM, SSP_CR1_MASK_RXIFLSEL_ST, 7) | \ + GEN_MASK_BITS(SSP_TX_1_OR_MORE_EMPTY_LOC, SSP_CR1_MASK_TXIFLSEL_ST, 10) | \ + GEN_MASK_BITS(SSP_FEEDBACK_CLK_DELAY_NONE, SSP_CR1_MASK_FBCLKDEL_ST, 13) \ +) + +#define DEFAULT_SSP_REG_CPSR ( \ + GEN_MASK_BITS(SSP_DEFAULT_PRESCALE, SSP_CPSR_MASK_CPSDVSR, 0) \ +) + +#define DEFAULT_SSP_REG_DMACR (\ + GEN_MASK_BITS(SSP_DMA_DISABLED, SSP_DMACR_MASK_RXDMAE, 0) | \ + GEN_MASK_BITS(SSP_DMA_DISABLED, SSP_DMACR_MASK_TXDMAE, 1) \ +) + +/** + * load_ssp_default_config - Load default configuration for SSP + * @pl022: SSP driver private data structure + */ +static void load_ssp_default_config(struct pl022 *pl022) +{ + if (pl022->vendor->pl023) { + writel(DEFAULT_SSP_REG_CR0_ST_PL023, SSP_CR0(pl022->virtbase)); + writew(DEFAULT_SSP_REG_CR1_ST_PL023, SSP_CR1(pl022->virtbase)); + } else if (pl022->vendor->extended_cr) { + writel(DEFAULT_SSP_REG_CR0_ST, SSP_CR0(pl022->virtbase)); + writew(DEFAULT_SSP_REG_CR1_ST, SSP_CR1(pl022->virtbase)); + } else { + writew(DEFAULT_SSP_REG_CR0, SSP_CR0(pl022->virtbase)); + writew(DEFAULT_SSP_REG_CR1, SSP_CR1(pl022->virtbase)); + } + writew(DEFAULT_SSP_REG_DMACR, SSP_DMACR(pl022->virtbase)); + writew(DEFAULT_SSP_REG_CPSR, SSP_CPSR(pl022->virtbase)); + writew(DISABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase)); + writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase)); +} + +/** + * This will write to TX and read from RX according to the parameters + * set in pl022. + */ +static void readwriter(struct pl022 *pl022) +{ + + /* + * The FIFO depth is different between primecell variants. + * I believe filling in too much in the FIFO might cause + * errons in 8bit wide transfers on ARM variants (just 8 words + * FIFO, means only 8x8 = 64 bits in FIFO) at least. + * + * To prevent this issue, the TX FIFO is only filled to the + * unused RX FIFO fill length, regardless of what the TX + * FIFO status flag indicates. + */ + dev_dbg(&pl022->adev->dev, + "%s, rx: %p, rxend: %p, tx: %p, txend: %p\n", + __func__, pl022->rx, pl022->rx_end, pl022->tx, pl022->tx_end); + + /* Read as much as you can */ + while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE) + && (pl022->rx < pl022->rx_end)) { + switch (pl022->read) { + case READING_NULL: + readw(SSP_DR(pl022->virtbase)); + break; + case READING_U8: + *(u8 *) (pl022->rx) = + readw(SSP_DR(pl022->virtbase)) & 0xFFU; + break; + case READING_U16: + *(u16 *) (pl022->rx) = + (u16) readw(SSP_DR(pl022->virtbase)); + break; + case READING_U32: + *(u32 *) (pl022->rx) = + readl(SSP_DR(pl022->virtbase)); + break; + } + pl022->rx += (pl022->cur_chip->n_bytes); + pl022->exp_fifo_level--; + } + /* + * Write as much as possible up to the RX FIFO size + */ + while ((pl022->exp_fifo_level < pl022->vendor->fifodepth) + && (pl022->tx < pl022->tx_end)) { + switch (pl022->write) { + case WRITING_NULL: + writew(0x0, SSP_DR(pl022->virtbase)); + break; + case WRITING_U8: + writew(*(u8 *) (pl022->tx), SSP_DR(pl022->virtbase)); + break; + case WRITING_U16: + writew((*(u16 *) (pl022->tx)), SSP_DR(pl022->virtbase)); + break; + case WRITING_U32: + writel(*(u32 *) (pl022->tx), SSP_DR(pl022->virtbase)); + break; + } + pl022->tx += (pl022->cur_chip->n_bytes); + pl022->exp_fifo_level++; + /* + * This inner reader takes care of things appearing in the RX + * FIFO as we're transmitting. This will happen a lot since the + * clock starts running when you put things into the TX FIFO, + * and then things are continuously clocked into the RX FIFO. + */ + while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE) + && (pl022->rx < pl022->rx_end)) { + switch (pl022->read) { + case READING_NULL: + readw(SSP_DR(pl022->virtbase)); + break; + case READING_U8: + *(u8 *) (pl022->rx) = + readw(SSP_DR(pl022->virtbase)) & 0xFFU; + break; + case READING_U16: + *(u16 *) (pl022->rx) = + (u16) readw(SSP_DR(pl022->virtbase)); + break; + case READING_U32: + *(u32 *) (pl022->rx) = + readl(SSP_DR(pl022->virtbase)); + break; + } + pl022->rx += (pl022->cur_chip->n_bytes); + pl022->exp_fifo_level--; + } + } + /* + * When we exit here the TX FIFO should be full and the RX FIFO + * should be empty + */ +} + +/** + * next_transfer - Move to the Next transfer in the current spi message + * @pl022: SSP driver private data structure + * + * This function moves though the linked list of spi transfers in the + * current spi message and returns with the state of current spi + * message i.e whether its last transfer is done(STATE_DONE) or + * Next transfer is ready(STATE_RUNNING) + */ +static void *next_transfer(struct pl022 *pl022) +{ + struct spi_message *msg = pl022->cur_msg; + struct spi_transfer *trans = pl022->cur_transfer; + + /* Move to next transfer */ + if (trans->transfer_list.next != &msg->transfers) { + pl022->cur_transfer = + list_entry(trans->transfer_list.next, + struct spi_transfer, transfer_list); + return STATE_RUNNING; + } + return STATE_DONE; +} + +/* + * This DMA functionality is only compiled in if we have + * access to the generic DMA devices/DMA engine. + */ +#ifdef CONFIG_DMA_ENGINE +static void unmap_free_dma_scatter(struct pl022 *pl022) +{ + /* Unmap and free the SG tables */ + dma_unmap_sg(pl022->dma_tx_channel->device->dev, pl022->sgt_tx.sgl, + pl022->sgt_tx.nents, DMA_TO_DEVICE); + dma_unmap_sg(pl022->dma_rx_channel->device->dev, pl022->sgt_rx.sgl, + pl022->sgt_rx.nents, DMA_FROM_DEVICE); + sg_free_table(&pl022->sgt_rx); + sg_free_table(&pl022->sgt_tx); +} + +static void dma_callback(void *data) +{ + struct pl022 *pl022 = data; + struct spi_message *msg = pl022->cur_msg; + + BUG_ON(!pl022->sgt_rx.sgl); + +#ifdef VERBOSE_DEBUG + /* + * Optionally dump out buffers to inspect contents, this is + * good if you want to convince yourself that the loopback + * read/write contents are the same, when adopting to a new + * DMA engine. + */ + { + struct scatterlist *sg; + unsigned int i; + + dma_sync_sg_for_cpu(&pl022->adev->dev, + pl022->sgt_rx.sgl, + pl022->sgt_rx.nents, + DMA_FROM_DEVICE); + + for_each_sg(pl022->sgt_rx.sgl, sg, pl022->sgt_rx.nents, i) { + dev_dbg(&pl022->adev->dev, "SPI RX SG ENTRY: %d", i); + print_hex_dump(KERN_ERR, "SPI RX: ", + DUMP_PREFIX_OFFSET, + 16, + 1, + sg_virt(sg), + sg_dma_len(sg), + 1); + } + for_each_sg(pl022->sgt_tx.sgl, sg, pl022->sgt_tx.nents, i) { + dev_dbg(&pl022->adev->dev, "SPI TX SG ENTRY: %d", i); + print_hex_dump(KERN_ERR, "SPI TX: ", + DUMP_PREFIX_OFFSET, + 16, + 1, + sg_virt(sg), + sg_dma_len(sg), + 1); + } + } +#endif + + unmap_free_dma_scatter(pl022); + + /* Update total bytes transferred */ + msg->actual_length += pl022->cur_transfer->len; + if (pl022->cur_transfer->cs_change) + pl022_cs_control(pl022, SSP_CHIP_DESELECT); + + /* Move to next transfer */ + msg->state = next_transfer(pl022); + tasklet_schedule(&pl022->pump_transfers); +} + +static void setup_dma_scatter(struct pl022 *pl022, + void *buffer, + unsigned int length, + struct sg_table *sgtab) +{ + struct scatterlist *sg; + int bytesleft = length; + void *bufp = buffer; + int mapbytes; + int i; + + if (buffer) { + for_each_sg(sgtab->sgl, sg, sgtab->nents, i) { + /* + * If there are less bytes left than what fits + * in the current page (plus page alignment offset) + * we just feed in this, else we stuff in as much + * as we can. + */ + if (bytesleft < (PAGE_SIZE - offset_in_page(bufp))) + mapbytes = bytesleft; + else + mapbytes = PAGE_SIZE - offset_in_page(bufp); + sg_set_page(sg, virt_to_page(bufp), + mapbytes, offset_in_page(bufp)); + bufp += mapbytes; + bytesleft -= mapbytes; + dev_dbg(&pl022->adev->dev, + "set RX/TX target page @ %p, %d bytes, %d left\n", + bufp, mapbytes, bytesleft); + } + } else { + /* Map the dummy buffer on every page */ + for_each_sg(sgtab->sgl, sg, sgtab->nents, i) { + if (bytesleft < PAGE_SIZE) + mapbytes = bytesleft; + else + mapbytes = PAGE_SIZE; + sg_set_page(sg, virt_to_page(pl022->dummypage), + mapbytes, 0); + bytesleft -= mapbytes; + dev_dbg(&pl022->adev->dev, + "set RX/TX to dummy page %d bytes, %d left\n", + mapbytes, bytesleft); + + } + } + BUG_ON(bytesleft); +} + +/** + * configure_dma - configures the channels for the next transfer + * @pl022: SSP driver's private data structure + */ +static int configure_dma(struct pl022 *pl022) +{ + struct dma_slave_config rx_conf = { + .src_addr = SSP_DR(pl022->phybase), + .direction = DMA_DEV_TO_MEM, + .device_fc = false, + }; + struct dma_slave_config tx_conf = { + .dst_addr = SSP_DR(pl022->phybase), + .direction = DMA_MEM_TO_DEV, + .device_fc = false, + }; + unsigned int pages; + int ret; + int rx_sglen, tx_sglen; + struct dma_chan *rxchan = pl022->dma_rx_channel; + struct dma_chan *txchan = pl022->dma_tx_channel; + struct dma_async_tx_descriptor *rxdesc; + struct dma_async_tx_descriptor *txdesc; + + /* Check that the channels are available */ + if (!rxchan || !txchan) + return -ENODEV; + + /* + * If supplied, the DMA burstsize should equal the FIFO trigger level. + * Notice that the DMA engine uses one-to-one mapping. Since we can + * not trigger on 2 elements this needs explicit mapping rather than + * calculation. + */ + switch (pl022->rx_lev_trig) { + case SSP_RX_1_OR_MORE_ELEM: + rx_conf.src_maxburst = 1; + break; + case SSP_RX_4_OR_MORE_ELEM: + rx_conf.src_maxburst = 4; + break; + case SSP_RX_8_OR_MORE_ELEM: + rx_conf.src_maxburst = 8; + break; + case SSP_RX_16_OR_MORE_ELEM: + rx_conf.src_maxburst = 16; + break; + case SSP_RX_32_OR_MORE_ELEM: + rx_conf.src_maxburst = 32; + break; + default: + rx_conf.src_maxburst = pl022->vendor->fifodepth >> 1; + break; + } + + switch (pl022->tx_lev_trig) { + case SSP_TX_1_OR_MORE_EMPTY_LOC: + tx_conf.dst_maxburst = 1; + break; + case SSP_TX_4_OR_MORE_EMPTY_LOC: + tx_conf.dst_maxburst = 4; + break; + case SSP_TX_8_OR_MORE_EMPTY_LOC: + tx_conf.dst_maxburst = 8; + break; + case SSP_TX_16_OR_MORE_EMPTY_LOC: + tx_conf.dst_maxburst = 16; + break; + case SSP_TX_32_OR_MORE_EMPTY_LOC: + tx_conf.dst_maxburst = 32; + break; + default: + tx_conf.dst_maxburst = pl022->vendor->fifodepth >> 1; + break; + } + + switch (pl022->read) { + case READING_NULL: + /* Use the same as for writing */ + rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_UNDEFINED; + break; + case READING_U8: + rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; + break; + case READING_U16: + rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES; + break; + case READING_U32: + rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; + break; + } + + switch (pl022->write) { + case WRITING_NULL: + /* Use the same as for reading */ + tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_UNDEFINED; + break; + case WRITING_U8: + tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; + break; + case WRITING_U16: + tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES; + break; + case WRITING_U32: + tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; + break; + } + + /* SPI pecularity: we need to read and write the same width */ + if (rx_conf.src_addr_width == DMA_SLAVE_BUSWIDTH_UNDEFINED) + rx_conf.src_addr_width = tx_conf.dst_addr_width; + if (tx_conf.dst_addr_width == DMA_SLAVE_BUSWIDTH_UNDEFINED) + tx_conf.dst_addr_width = rx_conf.src_addr_width; + BUG_ON(rx_conf.src_addr_width != tx_conf.dst_addr_width); + + dmaengine_slave_config(rxchan, &rx_conf); + dmaengine_slave_config(txchan, &tx_conf); + + /* Create sglists for the transfers */ + pages = DIV_ROUND_UP(pl022->cur_transfer->len, PAGE_SIZE); + dev_dbg(&pl022->adev->dev, "using %d pages for transfer\n", pages); + + ret = sg_alloc_table(&pl022->sgt_rx, pages, GFP_ATOMIC); + if (ret) + goto err_alloc_rx_sg; + + ret = sg_alloc_table(&pl022->sgt_tx, pages, GFP_ATOMIC); + if (ret) + goto err_alloc_tx_sg; + + /* Fill in the scatterlists for the RX+TX buffers */ + setup_dma_scatter(pl022, pl022->rx, + pl022->cur_transfer->len, &pl022->sgt_rx); + setup_dma_scatter(pl022, pl022->tx, + pl022->cur_transfer->len, &pl022->sgt_tx); + + /* Map DMA buffers */ + rx_sglen = dma_map_sg(rxchan->device->dev, pl022->sgt_rx.sgl, + pl022->sgt_rx.nents, DMA_FROM_DEVICE); + if (!rx_sglen) + goto err_rx_sgmap; + + tx_sglen = dma_map_sg(txchan->device->dev, pl022->sgt_tx.sgl, + pl022->sgt_tx.nents, DMA_TO_DEVICE); + if (!tx_sglen) + goto err_tx_sgmap; + + /* Send both scatterlists */ + rxdesc = dmaengine_prep_slave_sg(rxchan, + pl022->sgt_rx.sgl, + rx_sglen, + DMA_DEV_TO_MEM, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!rxdesc) + goto err_rxdesc; + + txdesc = dmaengine_prep_slave_sg(txchan, + pl022->sgt_tx.sgl, + tx_sglen, + DMA_MEM_TO_DEV, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!txdesc) + goto err_txdesc; + + /* Put the callback on the RX transfer only, that should finish last */ + rxdesc->callback = dma_callback; + rxdesc->callback_param = pl022; + + /* Submit and fire RX and TX with TX last so we're ready to read! */ + dmaengine_submit(rxdesc); + dmaengine_submit(txdesc); + dma_async_issue_pending(rxchan); + dma_async_issue_pending(txchan); + pl022->dma_running = true; + + return 0; + +err_txdesc: + dmaengine_terminate_all(txchan); +err_rxdesc: + dmaengine_terminate_all(rxchan); + dma_unmap_sg(txchan->device->dev, pl022->sgt_tx.sgl, + pl022->sgt_tx.nents, DMA_TO_DEVICE); +err_tx_sgmap: + dma_unmap_sg(rxchan->device->dev, pl022->sgt_rx.sgl, + pl022->sgt_tx.nents, DMA_FROM_DEVICE); +err_rx_sgmap: + sg_free_table(&pl022->sgt_tx); +err_alloc_tx_sg: + sg_free_table(&pl022->sgt_rx); +err_alloc_rx_sg: + return -ENOMEM; +} + +static int pl022_dma_probe(struct pl022 *pl022) +{ + dma_cap_mask_t mask; + + /* Try to acquire a generic DMA engine slave channel */ + dma_cap_zero(mask); + dma_cap_set(DMA_SLAVE, mask); + /* + * We need both RX and TX channels to do DMA, else do none + * of them. + */ + pl022->dma_rx_channel = dma_request_channel(mask, + pl022->master_info->dma_filter, + pl022->master_info->dma_rx_param); + if (!pl022->dma_rx_channel) { + dev_dbg(&pl022->adev->dev, "no RX DMA channel!\n"); + goto err_no_rxchan; + } + + pl022->dma_tx_channel = dma_request_channel(mask, + pl022->master_info->dma_filter, + pl022->master_info->dma_tx_param); + if (!pl022->dma_tx_channel) { + dev_dbg(&pl022->adev->dev, "no TX DMA channel!\n"); + goto err_no_txchan; + } + + pl022->dummypage = kmalloc(PAGE_SIZE, GFP_KERNEL); + if (!pl022->dummypage) + goto err_no_dummypage; + + dev_info(&pl022->adev->dev, "setup for DMA on RX %s, TX %s\n", + dma_chan_name(pl022->dma_rx_channel), + dma_chan_name(pl022->dma_tx_channel)); + + return 0; + +err_no_dummypage: + dma_release_channel(pl022->dma_tx_channel); +err_no_txchan: + dma_release_channel(pl022->dma_rx_channel); + pl022->dma_rx_channel = NULL; +err_no_rxchan: + dev_err(&pl022->adev->dev, + "Failed to work in dma mode, work without dma!\n"); + return -ENODEV; +} + +static int pl022_dma_autoprobe(struct pl022 *pl022) +{ + struct device *dev = &pl022->adev->dev; + + /* automatically configure DMA channels from platform, normally using DT */ + pl022->dma_rx_channel = dma_request_slave_channel(dev, "rx"); + if (!pl022->dma_rx_channel) + goto err_no_rxchan; + + pl022->dma_tx_channel = dma_request_slave_channel(dev, "tx"); + if (!pl022->dma_tx_channel) + goto err_no_txchan; + + pl022->dummypage = kmalloc(PAGE_SIZE, GFP_KERNEL); + if (!pl022->dummypage) + goto err_no_dummypage; + + return 0; + +err_no_dummypage: + dma_release_channel(pl022->dma_tx_channel); + pl022->dma_tx_channel = NULL; +err_no_txchan: + dma_release_channel(pl022->dma_rx_channel); + pl022->dma_rx_channel = NULL; +err_no_rxchan: + return -ENODEV; +} + +static void terminate_dma(struct pl022 *pl022) +{ + struct dma_chan *rxchan = pl022->dma_rx_channel; + struct dma_chan *txchan = pl022->dma_tx_channel; + + dmaengine_terminate_all(rxchan); + dmaengine_terminate_all(txchan); + unmap_free_dma_scatter(pl022); + pl022->dma_running = false; +} + +static void pl022_dma_remove(struct pl022 *pl022) +{ + if (pl022->dma_running) + terminate_dma(pl022); + if (pl022->dma_tx_channel) + dma_release_channel(pl022->dma_tx_channel); + if (pl022->dma_rx_channel) + dma_release_channel(pl022->dma_rx_channel); + kfree(pl022->dummypage); +} + +#else +static inline int configure_dma(struct pl022 *pl022) +{ + return -ENODEV; +} + +static inline int pl022_dma_autoprobe(struct pl022 *pl022) +{ + return 0; +} + +static inline int pl022_dma_probe(struct pl022 *pl022) +{ + return 0; +} + +static inline void pl022_dma_remove(struct pl022 *pl022) +{ +} +#endif + +/** + * pl022_interrupt_handler - Interrupt handler for SSP controller + * + * This function handles interrupts generated for an interrupt based transfer. + * If a receive overrun (ROR) interrupt is there then we disable SSP, flag the + * current message's state as STATE_ERROR and schedule the tasklet + * pump_transfers which will do the postprocessing of the current message by + * calling giveback(). Otherwise it reads data from RX FIFO till there is no + * more data, and writes data in TX FIFO till it is not full. If we complete + * the transfer we move to the next transfer and schedule the tasklet. + */ +static irqreturn_t pl022_interrupt_handler(int irq, void *dev_id) +{ + struct pl022 *pl022 = dev_id; + struct spi_message *msg = pl022->cur_msg; + u16 irq_status = 0; + u16 flag = 0; + + if (unlikely(!msg)) { + dev_err(&pl022->adev->dev, + "bad message state in interrupt handler"); + /* Never fail */ + return IRQ_HANDLED; + } + + /* Read the Interrupt Status Register */ + irq_status = readw(SSP_MIS(pl022->virtbase)); + + if (unlikely(!irq_status)) + return IRQ_NONE; + + /* + * This handles the FIFO interrupts, the timeout + * interrupts are flatly ignored, they cannot be + * trusted. + */ + if (unlikely(irq_status & SSP_MIS_MASK_RORMIS)) { + /* + * Overrun interrupt - bail out since our Data has been + * corrupted + */ + dev_err(&pl022->adev->dev, "FIFO overrun\n"); + if (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RFF) + dev_err(&pl022->adev->dev, + "RXFIFO is full\n"); + if (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_TNF) + dev_err(&pl022->adev->dev, + "TXFIFO is full\n"); + + /* + * Disable and clear interrupts, disable SSP, + * mark message with bad status so it can be + * retried. + */ + writew(DISABLE_ALL_INTERRUPTS, + SSP_IMSC(pl022->virtbase)); + writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase)); + writew((readw(SSP_CR1(pl022->virtbase)) & + (~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase)); + msg->state = STATE_ERROR; + + /* Schedule message queue handler */ + tasklet_schedule(&pl022->pump_transfers); + return IRQ_HANDLED; + } + + readwriter(pl022); + + if ((pl022->tx == pl022->tx_end) && (flag == 0)) { + flag = 1; + /* Disable Transmit interrupt, enable receive interrupt */ + writew((readw(SSP_IMSC(pl022->virtbase)) & + ~SSP_IMSC_MASK_TXIM) | SSP_IMSC_MASK_RXIM, + SSP_IMSC(pl022->virtbase)); + } + + /* + * Since all transactions must write as much as shall be read, + * we can conclude the entire transaction once RX is complete. + * At this point, all TX will always be finished. + */ + if (pl022->rx >= pl022->rx_end) { + writew(DISABLE_ALL_INTERRUPTS, + SSP_IMSC(pl022->virtbase)); + writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase)); + if (unlikely(pl022->rx > pl022->rx_end)) { + dev_warn(&pl022->adev->dev, "read %u surplus " + "bytes (did you request an odd " + "number of bytes on a 16bit bus?)\n", + (u32) (pl022->rx - pl022->rx_end)); + } + /* Update total bytes transferred */ + msg->actual_length += pl022->cur_transfer->len; + if (pl022->cur_transfer->cs_change) + pl022_cs_control(pl022, SSP_CHIP_DESELECT); + /* Move to next transfer */ + msg->state = next_transfer(pl022); + tasklet_schedule(&pl022->pump_transfers); + return IRQ_HANDLED; + } + + return IRQ_HANDLED; +} + +/** + * This sets up the pointers to memory for the next message to + * send out on the SPI bus. + */ +static int set_up_next_transfer(struct pl022 *pl022, + struct spi_transfer *transfer) +{ + int residue; + + /* Sanity check the message for this bus width */ + residue = pl022->cur_transfer->len % pl022->cur_chip->n_bytes; + if (unlikely(residue != 0)) { + dev_err(&pl022->adev->dev, + "message of %u bytes to transmit but the current " + "chip bus has a data width of %u bytes!\n", + pl022->cur_transfer->len, + pl022->cur_chip->n_bytes); + dev_err(&pl022->adev->dev, "skipping this message\n"); + return -EIO; + } + pl022->tx = (void *)transfer->tx_buf; + pl022->tx_end = pl022->tx + pl022->cur_transfer->len; + pl022->rx = (void *)transfer->rx_buf; + pl022->rx_end = pl022->rx + pl022->cur_transfer->len; + pl022->write = + pl022->tx ? pl022->cur_chip->write : WRITING_NULL; + pl022->read = pl022->rx ? pl022->cur_chip->read : READING_NULL; + return 0; +} + +/** + * pump_transfers - Tasklet function which schedules next transfer + * when running in interrupt or DMA transfer mode. + * @data: SSP driver private data structure + * + */ +static void pump_transfers(unsigned long data) +{ + struct pl022 *pl022 = (struct pl022 *) data; + struct spi_message *message = NULL; + struct spi_transfer *transfer = NULL; + struct spi_transfer *previous = NULL; + + /* Get current state information */ + message = pl022->cur_msg; + transfer = pl022->cur_transfer; + + /* Handle for abort */ + if (message->state == STATE_ERROR) { + message->status = -EIO; + giveback(pl022); + return; + } + + /* Handle end of message */ + if (message->state == STATE_DONE) { + message->status = 0; + giveback(pl022); + return; + } + + /* Delay if requested at end of transfer before CS change */ + if (message->state == STATE_RUNNING) { + previous = list_entry(transfer->transfer_list.prev, + struct spi_transfer, + transfer_list); + if (previous->delay_usecs) + /* + * FIXME: This runs in interrupt context. + * Is this really smart? + */ + udelay(previous->delay_usecs); + + /* Reselect chip select only if cs_change was requested */ + if (previous->cs_change) + pl022_cs_control(pl022, SSP_CHIP_SELECT); + } else { + /* STATE_START */ + message->state = STATE_RUNNING; + } + + if (set_up_next_transfer(pl022, transfer)) { + message->state = STATE_ERROR; + message->status = -EIO; + giveback(pl022); + return; + } + /* Flush the FIFOs and let's go! */ + flush(pl022); + + if (pl022->cur_chip->enable_dma) { + if (configure_dma(pl022)) { + dev_dbg(&pl022->adev->dev, + "configuration of DMA failed, fall back to interrupt mode\n"); + goto err_config_dma; + } + return; + } + +err_config_dma: + /* enable all interrupts except RX */ + writew(ENABLE_ALL_INTERRUPTS & ~SSP_IMSC_MASK_RXIM, SSP_IMSC(pl022->virtbase)); +} + +static void do_interrupt_dma_transfer(struct pl022 *pl022) +{ + /* + * Default is to enable all interrupts except RX - + * this will be enabled once TX is complete + */ + u32 irqflags = ENABLE_ALL_INTERRUPTS & ~SSP_IMSC_MASK_RXIM; + + /* Enable target chip, if not already active */ + if (!pl022->next_msg_cs_active) + pl022_cs_control(pl022, SSP_CHIP_SELECT); + + if (set_up_next_transfer(pl022, pl022->cur_transfer)) { + /* Error path */ + pl022->cur_msg->state = STATE_ERROR; + pl022->cur_msg->status = -EIO; + giveback(pl022); + return; + } + /* If we're using DMA, set up DMA here */ + if (pl022->cur_chip->enable_dma) { + /* Configure DMA transfer */ + if (configure_dma(pl022)) { + dev_dbg(&pl022->adev->dev, + "configuration of DMA failed, fall back to interrupt mode\n"); + goto err_config_dma; + } + /* Disable interrupts in DMA mode, IRQ from DMA controller */ + irqflags = DISABLE_ALL_INTERRUPTS; + } +err_config_dma: + /* Enable SSP, turn on interrupts */ + writew((readw(SSP_CR1(pl022->virtbase)) | SSP_CR1_MASK_SSE), + SSP_CR1(pl022->virtbase)); + writew(irqflags, SSP_IMSC(pl022->virtbase)); +} + +static void do_polling_transfer(struct pl022 *pl022) +{ + struct spi_message *message = NULL; + struct spi_transfer *transfer = NULL; + struct spi_transfer *previous = NULL; + struct chip_data *chip; + unsigned long time, timeout; + + chip = pl022->cur_chip; + message = pl022->cur_msg; + + while (message->state != STATE_DONE) { + /* Handle for abort */ + if (message->state == STATE_ERROR) + break; + transfer = pl022->cur_transfer; + + /* Delay if requested at end of transfer */ + if (message->state == STATE_RUNNING) { + previous = + list_entry(transfer->transfer_list.prev, + struct spi_transfer, transfer_list); + if (previous->delay_usecs) + udelay(previous->delay_usecs); + if (previous->cs_change) + pl022_cs_control(pl022, SSP_CHIP_SELECT); + } else { + /* STATE_START */ + message->state = STATE_RUNNING; + if (!pl022->next_msg_cs_active) + pl022_cs_control(pl022, SSP_CHIP_SELECT); + } + + /* Configuration Changing Per Transfer */ + if (set_up_next_transfer(pl022, transfer)) { + /* Error path */ + message->state = STATE_ERROR; + break; + } + /* Flush FIFOs and enable SSP */ + flush(pl022); + writew((readw(SSP_CR1(pl022->virtbase)) | SSP_CR1_MASK_SSE), + SSP_CR1(pl022->virtbase)); + + dev_dbg(&pl022->adev->dev, "polling transfer ongoing ...\n"); + + timeout = jiffies + msecs_to_jiffies(SPI_POLLING_TIMEOUT); + while (pl022->tx < pl022->tx_end || pl022->rx < pl022->rx_end) { + time = jiffies; + readwriter(pl022); + if (time_after(time, timeout)) { + dev_warn(&pl022->adev->dev, + "%s: timeout!\n", __func__); + message->state = STATE_ERROR; + goto out; + } + cpu_relax(); + } + + /* Update total byte transferred */ + message->actual_length += pl022->cur_transfer->len; + if (pl022->cur_transfer->cs_change) + pl022_cs_control(pl022, SSP_CHIP_DESELECT); + /* Move to next transfer */ + message->state = next_transfer(pl022); + } +out: + /* Handle end of message */ + if (message->state == STATE_DONE) + message->status = 0; + else + message->status = -EIO; + + giveback(pl022); + return; +} + +static int pl022_transfer_one_message(struct spi_master *master, + struct spi_message *msg) +{ + struct pl022 *pl022 = spi_master_get_devdata(master); + + /* Initial message state */ + pl022->cur_msg = msg; + msg->state = STATE_START; + + pl022->cur_transfer = list_entry(msg->transfers.next, + struct spi_transfer, transfer_list); + + /* Setup the SPI using the per chip configuration */ + pl022->cur_chip = spi_get_ctldata(msg->spi); + pl022->cur_cs = pl022->chipselects[msg->spi->chip_select]; + + restore_state(pl022); + flush(pl022); + + if (pl022->cur_chip->xfer_type == POLLING_TRANSFER) + do_polling_transfer(pl022); + else + do_interrupt_dma_transfer(pl022); + + return 0; +} + +static int pl022_unprepare_transfer_hardware(struct spi_master *master) +{ + struct pl022 *pl022 = spi_master_get_devdata(master); + + /* nothing more to do - disable spi/ssp and power off */ + writew((readw(SSP_CR1(pl022->virtbase)) & + (~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase)); + + return 0; +} + +static int verify_controller_parameters(struct pl022 *pl022, + struct pl022_config_chip const *chip_info) +{ + if ((chip_info->iface < SSP_INTERFACE_MOTOROLA_SPI) + || (chip_info->iface > SSP_INTERFACE_UNIDIRECTIONAL)) { + dev_err(&pl022->adev->dev, + "interface is configured incorrectly\n"); + return -EINVAL; + } + if ((chip_info->iface == SSP_INTERFACE_UNIDIRECTIONAL) && + (!pl022->vendor->unidir)) { + dev_err(&pl022->adev->dev, + "unidirectional mode not supported in this " + "hardware version\n"); + return -EINVAL; + } + if ((chip_info->hierarchy != SSP_MASTER) + && (chip_info->hierarchy != SSP_SLAVE)) { + dev_err(&pl022->adev->dev, + "hierarchy is configured incorrectly\n"); + return -EINVAL; + } + if ((chip_info->com_mode != INTERRUPT_TRANSFER) + && (chip_info->com_mode != DMA_TRANSFER) + && (chip_info->com_mode != POLLING_TRANSFER)) { + dev_err(&pl022->adev->dev, + "Communication mode is configured incorrectly\n"); + return -EINVAL; + } + switch (chip_info->rx_lev_trig) { + case SSP_RX_1_OR_MORE_ELEM: + case SSP_RX_4_OR_MORE_ELEM: + case SSP_RX_8_OR_MORE_ELEM: + /* These are always OK, all variants can handle this */ + break; + case SSP_RX_16_OR_MORE_ELEM: + if (pl022->vendor->fifodepth < 16) { + dev_err(&pl022->adev->dev, + "RX FIFO Trigger Level is configured incorrectly\n"); + return -EINVAL; + } + break; + case SSP_RX_32_OR_MORE_ELEM: + if (pl022->vendor->fifodepth < 32) { + dev_err(&pl022->adev->dev, + "RX FIFO Trigger Level is configured incorrectly\n"); + return -EINVAL; + } + break; + default: + dev_err(&pl022->adev->dev, + "RX FIFO Trigger Level is configured incorrectly\n"); + return -EINVAL; + } + switch (chip_info->tx_lev_trig) { + case SSP_TX_1_OR_MORE_EMPTY_LOC: + case SSP_TX_4_OR_MORE_EMPTY_LOC: + case SSP_TX_8_OR_MORE_EMPTY_LOC: + /* These are always OK, all variants can handle this */ + break; + case SSP_TX_16_OR_MORE_EMPTY_LOC: + if (pl022->vendor->fifodepth < 16) { + dev_err(&pl022->adev->dev, + "TX FIFO Trigger Level is configured incorrectly\n"); + return -EINVAL; + } + break; + case SSP_TX_32_OR_MORE_EMPTY_LOC: + if (pl022->vendor->fifodepth < 32) { + dev_err(&pl022->adev->dev, + "TX FIFO Trigger Level is configured incorrectly\n"); + return -EINVAL; + } + break; + default: + dev_err(&pl022->adev->dev, + "TX FIFO Trigger Level is configured incorrectly\n"); + return -EINVAL; + } + if (chip_info->iface == SSP_INTERFACE_NATIONAL_MICROWIRE) { + if ((chip_info->ctrl_len < SSP_BITS_4) + || (chip_info->ctrl_len > SSP_BITS_32)) { + dev_err(&pl022->adev->dev, + "CTRL LEN is configured incorrectly\n"); + return -EINVAL; + } + if ((chip_info->wait_state != SSP_MWIRE_WAIT_ZERO) + && (chip_info->wait_state != SSP_MWIRE_WAIT_ONE)) { + dev_err(&pl022->adev->dev, + "Wait State is configured incorrectly\n"); + return -EINVAL; + } + /* Half duplex is only available in the ST Micro version */ + if (pl022->vendor->extended_cr) { + if ((chip_info->duplex != + SSP_MICROWIRE_CHANNEL_FULL_DUPLEX) + && (chip_info->duplex != + SSP_MICROWIRE_CHANNEL_HALF_DUPLEX)) { + dev_err(&pl022->adev->dev, + "Microwire duplex mode is configured incorrectly\n"); + return -EINVAL; + } + } else { + if (chip_info->duplex != SSP_MICROWIRE_CHANNEL_FULL_DUPLEX) + dev_err(&pl022->adev->dev, + "Microwire half duplex mode requested," + " but this is only available in the" + " ST version of PL022\n"); + return -EINVAL; + } + } + return 0; +} + +static inline u32 spi_rate(u32 rate, u16 cpsdvsr, u16 scr) +{ + return rate / (cpsdvsr * (1 + scr)); +} + +static int calculate_effective_freq(struct pl022 *pl022, int freq, struct + ssp_clock_params * clk_freq) +{ + /* Lets calculate the frequency parameters */ + u16 cpsdvsr = CPSDVR_MIN, scr = SCR_MIN; + u32 rate, max_tclk, min_tclk, best_freq = 0, best_cpsdvsr = 0, + best_scr = 0, tmp, found = 0; + + rate = clk_get_rate(pl022->clk); + /* cpsdvscr = 2 & scr 0 */ + max_tclk = spi_rate(rate, CPSDVR_MIN, SCR_MIN); + /* cpsdvsr = 254 & scr = 255 */ + min_tclk = spi_rate(rate, CPSDVR_MAX, SCR_MAX); + + if (freq > max_tclk) + dev_warn(&pl022->adev->dev, + "Max speed that can be programmed is %d Hz, you requested %d\n", + max_tclk, freq); + + if (freq < min_tclk) { + dev_err(&pl022->adev->dev, + "Requested frequency: %d Hz is less than minimum possible %d Hz\n", + freq, min_tclk); + return -EINVAL; + } + + /* + * best_freq will give closest possible available rate (<= requested + * freq) for all values of scr & cpsdvsr. + */ + while ((cpsdvsr <= CPSDVR_MAX) && !found) { + while (scr <= SCR_MAX) { + tmp = spi_rate(rate, cpsdvsr, scr); + + if (tmp > freq) { + /* we need lower freq */ + scr++; + continue; + } + + /* + * If found exact value, mark found and break. + * If found more closer value, update and break. + */ + if (tmp > best_freq) { + best_freq = tmp; + best_cpsdvsr = cpsdvsr; + best_scr = scr; + + if (tmp == freq) + found = 1; + } + /* + * increased scr will give lower rates, which are not + * required + */ + break; + } + cpsdvsr += 2; + scr = SCR_MIN; + } + + WARN(!best_freq, "pl022: Matching cpsdvsr and scr not found for %d Hz rate \n", + freq); + + clk_freq->cpsdvsr = (u8) (best_cpsdvsr & 0xFF); + clk_freq->scr = (u8) (best_scr & 0xFF); + dev_dbg(&pl022->adev->dev, + "SSP Target Frequency is: %u, Effective Frequency is %u\n", + freq, best_freq); + dev_dbg(&pl022->adev->dev, "SSP cpsdvsr = %d, scr = %d\n", + clk_freq->cpsdvsr, clk_freq->scr); + + return 0; +} + +/* + * A piece of default chip info unless the platform + * supplies it. + */ +static const struct pl022_config_chip pl022_default_chip_info = { + .com_mode = POLLING_TRANSFER, + .iface = SSP_INTERFACE_MOTOROLA_SPI, + .hierarchy = SSP_SLAVE, + .slave_tx_disable = DO_NOT_DRIVE_TX, + .rx_lev_trig = SSP_RX_1_OR_MORE_ELEM, + .tx_lev_trig = SSP_TX_1_OR_MORE_EMPTY_LOC, + .ctrl_len = SSP_BITS_8, + .wait_state = SSP_MWIRE_WAIT_ZERO, + .duplex = SSP_MICROWIRE_CHANNEL_FULL_DUPLEX, + .cs_control = null_cs_control, +}; + +/** + * pl022_setup - setup function registered to SPI master framework + * @spi: spi device which is requesting setup + * + * This function is registered to the SPI framework for this SPI master + * controller. If it is the first time when setup is called by this device, + * this function will initialize the runtime state for this chip and save + * the same in the device structure. Else it will update the runtime info + * with the updated chip info. Nothing is really being written to the + * controller hardware here, that is not done until the actual transfer + * commence. + */ +static int pl022_setup(struct spi_device *spi) +{ + struct pl022_config_chip const *chip_info; + struct pl022_config_chip chip_info_dt; + struct chip_data *chip; + struct ssp_clock_params clk_freq = { .cpsdvsr = 0, .scr = 0}; + int status = 0; + struct pl022 *pl022 = spi_master_get_devdata(spi->master); + unsigned int bits = spi->bits_per_word; + u32 tmp; + struct device_node *np = spi->dev.of_node; + + if (!spi->max_speed_hz) + return -EINVAL; + + /* Get controller_state if one is supplied */ + chip = spi_get_ctldata(spi); + + if (chip == NULL) { + chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL); + if (!chip) + return -ENOMEM; + dev_dbg(&spi->dev, + "allocated memory for controller's runtime state\n"); + } + + /* Get controller data if one is supplied */ + chip_info = spi->controller_data; + + if (chip_info == NULL) { + if (np) { + chip_info_dt = pl022_default_chip_info; + + chip_info_dt.hierarchy = SSP_MASTER; + of_property_read_u32(np, "pl022,interface", + &chip_info_dt.iface); + of_property_read_u32(np, "pl022,com-mode", + &chip_info_dt.com_mode); + of_property_read_u32(np, "pl022,rx-level-trig", + &chip_info_dt.rx_lev_trig); + of_property_read_u32(np, "pl022,tx-level-trig", + &chip_info_dt.tx_lev_trig); + of_property_read_u32(np, "pl022,ctrl-len", + &chip_info_dt.ctrl_len); + of_property_read_u32(np, "pl022,wait-state", + &chip_info_dt.wait_state); + of_property_read_u32(np, "pl022,duplex", + &chip_info_dt.duplex); + + chip_info = &chip_info_dt; + } else { + chip_info = &pl022_default_chip_info; + /* spi_board_info.controller_data not is supplied */ + dev_dbg(&spi->dev, + "using default controller_data settings\n"); + } + } else + dev_dbg(&spi->dev, + "using user supplied controller_data settings\n"); + + /* + * We can override with custom divisors, else we use the board + * frequency setting + */ + if ((0 == chip_info->clk_freq.cpsdvsr) + && (0 == chip_info->clk_freq.scr)) { + status = calculate_effective_freq(pl022, + spi->max_speed_hz, + &clk_freq); + if (status < 0) + goto err_config_params; + } else { + memcpy(&clk_freq, &chip_info->clk_freq, sizeof(clk_freq)); + if ((clk_freq.cpsdvsr % 2) != 0) + clk_freq.cpsdvsr = + clk_freq.cpsdvsr - 1; + } + if ((clk_freq.cpsdvsr < CPSDVR_MIN) + || (clk_freq.cpsdvsr > CPSDVR_MAX)) { + status = -EINVAL; + dev_err(&spi->dev, + "cpsdvsr is configured incorrectly\n"); + goto err_config_params; + } + + status = verify_controller_parameters(pl022, chip_info); + if (status) { + dev_err(&spi->dev, "controller data is incorrect"); + goto err_config_params; + } + + pl022->rx_lev_trig = chip_info->rx_lev_trig; + pl022->tx_lev_trig = chip_info->tx_lev_trig; + + /* Now set controller state based on controller data */ + chip->xfer_type = chip_info->com_mode; + if (!chip_info->cs_control) { + chip->cs_control = null_cs_control; + if (!gpio_is_valid(pl022->chipselects[spi->chip_select])) + dev_warn(&spi->dev, + "invalid chip select\n"); + } else + chip->cs_control = chip_info->cs_control; + + /* Check bits per word with vendor specific range */ + if ((bits <= 3) || (bits > pl022->vendor->max_bpw)) { + status = -ENOTSUPP; + dev_err(&spi->dev, "illegal data size for this controller!\n"); + dev_err(&spi->dev, "This controller can only handle 4 <= n <= %d bit words\n", + pl022->vendor->max_bpw); + goto err_config_params; + } else if (bits <= 8) { + dev_dbg(&spi->dev, "4 <= n <=8 bits per word\n"); + chip->n_bytes = 1; + chip->read = READING_U8; + chip->write = WRITING_U8; + } else if (bits <= 16) { + dev_dbg(&spi->dev, "9 <= n <= 16 bits per word\n"); + chip->n_bytes = 2; + chip->read = READING_U16; + chip->write = WRITING_U16; + } else { + dev_dbg(&spi->dev, "17 <= n <= 32 bits per word\n"); + chip->n_bytes = 4; + chip->read = READING_U32; + chip->write = WRITING_U32; + } + + /* Now Initialize all register settings required for this chip */ + chip->cr0 = 0; + chip->cr1 = 0; + chip->dmacr = 0; + chip->cpsr = 0; + if ((chip_info->com_mode == DMA_TRANSFER) + && ((pl022->master_info)->enable_dma)) { + chip->enable_dma = true; + dev_dbg(&spi->dev, "DMA mode set in controller state\n"); + SSP_WRITE_BITS(chip->dmacr, SSP_DMA_ENABLED, + SSP_DMACR_MASK_RXDMAE, 0); + SSP_WRITE_BITS(chip->dmacr, SSP_DMA_ENABLED, + SSP_DMACR_MASK_TXDMAE, 1); + } else { + chip->enable_dma = false; + dev_dbg(&spi->dev, "DMA mode NOT set in controller state\n"); + SSP_WRITE_BITS(chip->dmacr, SSP_DMA_DISABLED, + SSP_DMACR_MASK_RXDMAE, 0); + SSP_WRITE_BITS(chip->dmacr, SSP_DMA_DISABLED, + SSP_DMACR_MASK_TXDMAE, 1); + } + + chip->cpsr = clk_freq.cpsdvsr; + + /* Special setup for the ST micro extended control registers */ + if (pl022->vendor->extended_cr) { + u32 etx; + + if (pl022->vendor->pl023) { + /* These bits are only in the PL023 */ + SSP_WRITE_BITS(chip->cr1, chip_info->clkdelay, + SSP_CR1_MASK_FBCLKDEL_ST, 13); + } else { + /* These bits are in the PL022 but not PL023 */ + SSP_WRITE_BITS(chip->cr0, chip_info->duplex, + SSP_CR0_MASK_HALFDUP_ST, 5); + SSP_WRITE_BITS(chip->cr0, chip_info->ctrl_len, + SSP_CR0_MASK_CSS_ST, 16); + SSP_WRITE_BITS(chip->cr0, chip_info->iface, + SSP_CR0_MASK_FRF_ST, 21); + SSP_WRITE_BITS(chip->cr1, chip_info->wait_state, + SSP_CR1_MASK_MWAIT_ST, 6); + } + SSP_WRITE_BITS(chip->cr0, bits - 1, + SSP_CR0_MASK_DSS_ST, 0); + + if (spi->mode & SPI_LSB_FIRST) { + tmp = SSP_RX_LSB; + etx = SSP_TX_LSB; + } else { + tmp = SSP_RX_MSB; + etx = SSP_TX_MSB; + } + SSP_WRITE_BITS(chip->cr1, tmp, SSP_CR1_MASK_RENDN_ST, 4); + SSP_WRITE_BITS(chip->cr1, etx, SSP_CR1_MASK_TENDN_ST, 5); + SSP_WRITE_BITS(chip->cr1, chip_info->rx_lev_trig, + SSP_CR1_MASK_RXIFLSEL_ST, 7); + SSP_WRITE_BITS(chip->cr1, chip_info->tx_lev_trig, + SSP_CR1_MASK_TXIFLSEL_ST, 10); + } else { + SSP_WRITE_BITS(chip->cr0, bits - 1, + SSP_CR0_MASK_DSS, 0); + SSP_WRITE_BITS(chip->cr0, chip_info->iface, + SSP_CR0_MASK_FRF, 4); + } + + /* Stuff that is common for all versions */ + if (spi->mode & SPI_CPOL) + tmp = SSP_CLK_POL_IDLE_HIGH; + else + tmp = SSP_CLK_POL_IDLE_LOW; + SSP_WRITE_BITS(chip->cr0, tmp, SSP_CR0_MASK_SPO, 6); + + if (spi->mode & SPI_CPHA) + tmp = SSP_CLK_SECOND_EDGE; + else + tmp = SSP_CLK_FIRST_EDGE; + SSP_WRITE_BITS(chip->cr0, tmp, SSP_CR0_MASK_SPH, 7); + + SSP_WRITE_BITS(chip->cr0, clk_freq.scr, SSP_CR0_MASK_SCR, 8); + /* Loopback is available on all versions except PL023 */ + if (pl022->vendor->loopback) { + if (spi->mode & SPI_LOOP) + tmp = LOOPBACK_ENABLED; + else + tmp = LOOPBACK_DISABLED; + SSP_WRITE_BITS(chip->cr1, tmp, SSP_CR1_MASK_LBM, 0); + } + SSP_WRITE_BITS(chip->cr1, SSP_DISABLED, SSP_CR1_MASK_SSE, 1); + SSP_WRITE_BITS(chip->cr1, chip_info->hierarchy, SSP_CR1_MASK_MS, 2); + SSP_WRITE_BITS(chip->cr1, chip_info->slave_tx_disable, SSP_CR1_MASK_SOD, + 3); + + /* Save controller_state */ + spi_set_ctldata(spi, chip); + return status; + err_config_params: + spi_set_ctldata(spi, NULL); + kfree(chip); + return status; +} + +/** + * pl022_cleanup - cleanup function registered to SPI master framework + * @spi: spi device which is requesting cleanup + * + * This function is registered to the SPI framework for this SPI master + * controller. It will free the runtime state of chip. + */ +static void pl022_cleanup(struct spi_device *spi) +{ + struct chip_data *chip = spi_get_ctldata(spi); + + spi_set_ctldata(spi, NULL); + kfree(chip); +} + +static struct pl022_ssp_controller * +pl022_platform_data_dt_get(struct device *dev) +{ + struct device_node *np = dev->of_node; + struct pl022_ssp_controller *pd; + u32 tmp; + + if (!np) { + dev_err(dev, "no dt node defined\n"); + return NULL; + } + + pd = devm_kzalloc(dev, sizeof(struct pl022_ssp_controller), GFP_KERNEL); + if (!pd) + return NULL; + + pd->bus_id = -1; + pd->enable_dma = 1; + of_property_read_u32(np, "num-cs", &tmp); + pd->num_chipselect = tmp; + of_property_read_u32(np, "pl022,autosuspend-delay", + &pd->autosuspend_delay); + pd->rt = of_property_read_bool(np, "pl022,rt"); + + return pd; +} + +static int pl022_probe(struct amba_device *adev, const struct amba_id *id) +{ + struct device *dev = &adev->dev; + struct pl022_ssp_controller *platform_info = + dev_get_platdata(&adev->dev); + struct spi_master *master; + struct pl022 *pl022 = NULL; /*Data for this driver */ + struct device_node *np = adev->dev.of_node; + int status = 0, i, num_cs; + + dev_info(&adev->dev, + "ARM PL022 driver, device ID: 0x%08x\n", adev->periphid); + if (!platform_info && IS_ENABLED(CONFIG_OF)) + platform_info = pl022_platform_data_dt_get(dev); + + if (!platform_info) { + dev_err(dev, "probe: no platform data defined\n"); + return -ENODEV; + } + + if (platform_info->num_chipselect) { + num_cs = platform_info->num_chipselect; + } else { + dev_err(dev, "probe: no chip select defined\n"); + return -ENODEV; + } + + /* Allocate master with space for data */ + master = spi_alloc_master(dev, sizeof(struct pl022)); + if (master == NULL) { + dev_err(&adev->dev, "probe - cannot alloc SPI master\n"); + return -ENOMEM; + } + + pl022 = spi_master_get_devdata(master); + pl022->master = master; + pl022->master_info = platform_info; + pl022->adev = adev; + pl022->vendor = id->data; + pl022->chipselects = devm_kzalloc(dev, num_cs * sizeof(int), + GFP_KERNEL); + + /* + * Bus Number Which has been Assigned to this SSP controller + * on this board + */ + master->bus_num = platform_info->bus_id; + master->num_chipselect = num_cs; + master->cleanup = pl022_cleanup; + master->setup = pl022_setup; + master->auto_runtime_pm = true; + master->transfer_one_message = pl022_transfer_one_message; + master->unprepare_transfer_hardware = pl022_unprepare_transfer_hardware; + master->rt = platform_info->rt; + master->dev.of_node = dev->of_node; + + if (platform_info->num_chipselect && platform_info->chipselects) { + for (i = 0; i < num_cs; i++) + pl022->chipselects[i] = platform_info->chipselects[i]; + } else if (IS_ENABLED(CONFIG_OF)) { + for (i = 0; i < num_cs; i++) { + int cs_gpio = of_get_named_gpio(np, "cs-gpios", i); + + if (cs_gpio == -EPROBE_DEFER) { + status = -EPROBE_DEFER; + goto err_no_gpio; + } + + pl022->chipselects[i] = cs_gpio; + + if (gpio_is_valid(cs_gpio)) { + if (devm_gpio_request(dev, cs_gpio, "ssp-pl022")) + dev_err(&adev->dev, + "could not request %d gpio\n", + cs_gpio); + else if (gpio_direction_output(cs_gpio, 1)) + dev_err(&adev->dev, + "could set gpio %d as output\n", + cs_gpio); + } + } + } + + /* + * Supports mode 0-3, loopback, and active low CS. Transfers are + * always MS bit first on the original pl022. + */ + master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LOOP; + if (pl022->vendor->extended_cr) + master->mode_bits |= SPI_LSB_FIRST; + + dev_dbg(&adev->dev, "BUSNO: %d\n", master->bus_num); + + status = amba_request_regions(adev, NULL); + if (status) + goto err_no_ioregion; + + pl022->phybase = adev->res.start; + pl022->virtbase = devm_ioremap(dev, adev->res.start, + resource_size(&adev->res)); + if (pl022->virtbase == NULL) { + status = -ENOMEM; + goto err_no_ioremap; + } + dev_info(&adev->dev, "mapped registers from %pa to %p\n", + &adev->res.start, pl022->virtbase); + + pl022->clk = devm_clk_get(&adev->dev, NULL); + if (IS_ERR(pl022->clk)) { + status = PTR_ERR(pl022->clk); + dev_err(&adev->dev, "could not retrieve SSP/SPI bus clock\n"); + goto err_no_clk; + } + + status = clk_prepare_enable(pl022->clk); + if (status) { + dev_err(&adev->dev, "could not enable SSP/SPI bus clock\n"); + goto err_no_clk_en; + } + + /* Initialize transfer pump */ + tasklet_init(&pl022->pump_transfers, pump_transfers, + (unsigned long)pl022); + + /* Disable SSP */ + writew((readw(SSP_CR1(pl022->virtbase)) & (~SSP_CR1_MASK_SSE)), + SSP_CR1(pl022->virtbase)); + load_ssp_default_config(pl022); + + status = devm_request_irq(dev, adev->irq[0], pl022_interrupt_handler, + 0, "pl022", pl022); + if (status < 0) { + dev_err(&adev->dev, "probe - cannot get IRQ (%d)\n", status); + goto err_no_irq; + } + + /* Get DMA channels, try autoconfiguration first */ + status = pl022_dma_autoprobe(pl022); + + /* If that failed, use channels from platform_info */ + if (status == 0) + platform_info->enable_dma = 1; + else if (platform_info->enable_dma) { + status = pl022_dma_probe(pl022); + if (status != 0) + platform_info->enable_dma = 0; + } + + /* Register with the SPI framework */ + amba_set_drvdata(adev, pl022); + status = devm_spi_register_master(&adev->dev, master); + if (status != 0) { + dev_err(&adev->dev, + "probe - problem registering spi master\n"); + goto err_spi_register; + } + dev_dbg(dev, "probe succeeded\n"); + + /* let runtime pm put suspend */ + if (platform_info->autosuspend_delay > 0) { + dev_info(&adev->dev, + "will use autosuspend for runtime pm, delay %dms\n", + platform_info->autosuspend_delay); + pm_runtime_set_autosuspend_delay(dev, + platform_info->autosuspend_delay); + pm_runtime_use_autosuspend(dev); + } + pm_runtime_put(dev); + + return 0; + + err_spi_register: + if (platform_info->enable_dma) + pl022_dma_remove(pl022); + err_no_irq: + clk_disable_unprepare(pl022->clk); + err_no_clk_en: + err_no_clk: + err_no_ioremap: + amba_release_regions(adev); + err_no_ioregion: + err_no_gpio: + spi_master_put(master); + return status; +} + +static int +pl022_remove(struct amba_device *adev) +{ + struct pl022 *pl022 = amba_get_drvdata(adev); + + if (!pl022) + return 0; + + /* + * undo pm_runtime_put() in probe. I assume that we're not + * accessing the primecell here. + */ + pm_runtime_get_noresume(&adev->dev); + + load_ssp_default_config(pl022); + if (pl022->master_info->enable_dma) + pl022_dma_remove(pl022); + + clk_disable_unprepare(pl022->clk); + amba_release_regions(adev); + tasklet_disable(&pl022->pump_transfers); + return 0; +} + +#ifdef CONFIG_PM_SLEEP +static int pl022_suspend(struct device *dev) +{ + struct pl022 *pl022 = dev_get_drvdata(dev); + int ret; + + ret = spi_master_suspend(pl022->master); + if (ret) { + dev_warn(dev, "cannot suspend master\n"); + return ret; + } + + ret = pm_runtime_force_suspend(dev); + if (ret) { + spi_master_resume(pl022->master); + return ret; + } + + pinctrl_pm_select_sleep_state(dev); + + dev_dbg(dev, "suspended\n"); + return 0; +} + +static int pl022_resume(struct device *dev) +{ + struct pl022 *pl022 = dev_get_drvdata(dev); + int ret; + + ret = pm_runtime_force_resume(dev); + if (ret) + dev_err(dev, "problem resuming\n"); + + /* Start the queue running */ + ret = spi_master_resume(pl022->master); + if (ret) + dev_err(dev, "problem starting queue (%d)\n", ret); + else + dev_dbg(dev, "resumed\n"); + + return ret; +} +#endif + +#ifdef CONFIG_PM +static int pl022_runtime_suspend(struct device *dev) +{ + struct pl022 *pl022 = dev_get_drvdata(dev); + + clk_disable_unprepare(pl022->clk); + pinctrl_pm_select_idle_state(dev); + + return 0; +} + +static int pl022_runtime_resume(struct device *dev) +{ + struct pl022 *pl022 = dev_get_drvdata(dev); + + pinctrl_pm_select_default_state(dev); + clk_prepare_enable(pl022->clk); + + return 0; +} +#endif + +static const struct dev_pm_ops pl022_dev_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS(pl022_suspend, pl022_resume) + SET_PM_RUNTIME_PM_OPS(pl022_runtime_suspend, pl022_runtime_resume, NULL) +}; + +static struct vendor_data vendor_arm = { + .fifodepth = 8, + .max_bpw = 16, + .unidir = false, + .extended_cr = false, + .pl023 = false, + .loopback = true, +}; + +static struct vendor_data vendor_st = { + .fifodepth = 32, + .max_bpw = 32, + .unidir = false, + .extended_cr = true, + .pl023 = false, + .loopback = true, +}; + +static struct vendor_data vendor_st_pl023 = { + .fifodepth = 32, + .max_bpw = 32, + .unidir = false, + .extended_cr = true, + .pl023 = true, + .loopback = false, +}; + +static struct amba_id pl022_ids[] = { + { + /* + * ARM PL022 variant, this has a 16bit wide + * and 8 locations deep TX/RX FIFO + */ + .id = 0x00041022, + .mask = 0x000fffff, + .data = &vendor_arm, + }, + { + /* + * ST Micro derivative, this has 32bit wide + * and 32 locations deep TX/RX FIFO + */ + .id = 0x01080022, + .mask = 0xffffffff, + .data = &vendor_st, + }, + { + /* + * ST-Ericsson derivative "PL023" (this is not + * an official ARM number), this is a PL022 SSP block + * stripped to SPI mode only, it has 32bit wide + * and 32 locations deep TX/RX FIFO but no extended + * CR0/CR1 register + */ + .id = 0x00080023, + .mask = 0xffffffff, + .data = &vendor_st_pl023, + }, + { 0, 0 }, +}; + +MODULE_DEVICE_TABLE(amba, pl022_ids); + +static struct amba_driver pl022_driver = { + .drv = { + .name = "ssp-pl022", + .pm = &pl022_dev_pm_ops, + }, + .id_table = pl022_ids, + .probe = pl022_probe, + .remove = pl022_remove, +}; + +static int __init pl022_init(void) +{ + return amba_driver_register(&pl022_driver); +} +subsys_initcall(pl022_init); + +static void __exit pl022_exit(void) +{ + amba_driver_unregister(&pl022_driver); +} +module_exit(pl022_exit); + +MODULE_AUTHOR("Linus Walleij <linus.walleij@stericsson.com>"); +MODULE_DESCRIPTION("PL022 SSP Controller Driver"); +MODULE_LICENSE("GPL"); |