diff options
Diffstat (limited to 'drivers/spi/xilinx_spi.c')
| -rw-r--r-- | drivers/spi/xilinx_spi.c | 434 |
1 files changed, 0 insertions, 434 deletions
diff --git a/drivers/spi/xilinx_spi.c b/drivers/spi/xilinx_spi.c deleted file mode 100644 index 5d04f520c12..00000000000 --- a/drivers/spi/xilinx_spi.c +++ /dev/null @@ -1,434 +0,0 @@ -/* - * xilinx_spi.c - * - * Xilinx SPI controller driver (master mode only) - * - * Author: MontaVista Software, Inc. - * source@mvista.com - * - * 2002-2007 (c) MontaVista Software, Inc. This file is licensed under the - * terms of the GNU General Public License version 2. This program is licensed - * "as is" without any warranty of any kind, whether express or implied. - */ - -#include <linux/module.h> -#include <linux/init.h> -#include <linux/interrupt.h> -#include <linux/platform_device.h> -#include <linux/spi/spi.h> -#include <linux/spi/spi_bitbang.h> -#include <linux/io.h> - -#include <syslib/virtex_devices.h> - -#define XILINX_SPI_NAME "xilinx_spi" - -/* Register definitions as per "OPB Serial Peripheral Interface (SPI) (v1.00e) - * Product Specification", DS464 - */ -#define XSPI_CR_OFFSET 0x62 /* 16-bit Control Register */ - -#define XSPI_CR_ENABLE 0x02 -#define XSPI_CR_MASTER_MODE 0x04 -#define XSPI_CR_CPOL 0x08 -#define XSPI_CR_CPHA 0x10 -#define XSPI_CR_MODE_MASK (XSPI_CR_CPHA | XSPI_CR_CPOL) -#define XSPI_CR_TXFIFO_RESET 0x20 -#define XSPI_CR_RXFIFO_RESET 0x40 -#define XSPI_CR_MANUAL_SSELECT 0x80 -#define XSPI_CR_TRANS_INHIBIT 0x100 - -#define XSPI_SR_OFFSET 0x67 /* 8-bit Status Register */ - -#define XSPI_SR_RX_EMPTY_MASK 0x01 /* Receive FIFO is empty */ -#define XSPI_SR_RX_FULL_MASK 0x02 /* Receive FIFO is full */ -#define XSPI_SR_TX_EMPTY_MASK 0x04 /* Transmit FIFO is empty */ -#define XSPI_SR_TX_FULL_MASK 0x08 /* Transmit FIFO is full */ -#define XSPI_SR_MODE_FAULT_MASK 0x10 /* Mode fault error */ - -#define XSPI_TXD_OFFSET 0x6b /* 8-bit Data Transmit Register */ -#define XSPI_RXD_OFFSET 0x6f /* 8-bit Data Receive Register */ - -#define XSPI_SSR_OFFSET 0x70 /* 32-bit Slave Select Register */ - -/* Register definitions as per "OPB IPIF (v3.01c) Product Specification", DS414 - * IPIF registers are 32 bit - */ -#define XIPIF_V123B_DGIER_OFFSET 0x1c /* IPIF global int enable reg */ -#define XIPIF_V123B_GINTR_ENABLE 0x80000000 - -#define XIPIF_V123B_IISR_OFFSET 0x20 /* IPIF interrupt status reg */ -#define XIPIF_V123B_IIER_OFFSET 0x28 /* IPIF interrupt enable reg */ - -#define XSPI_INTR_MODE_FAULT 0x01 /* Mode fault error */ -#define XSPI_INTR_SLAVE_MODE_FAULT 0x02 /* Selected as slave while - * disabled */ -#define XSPI_INTR_TX_EMPTY 0x04 /* TxFIFO is empty */ -#define XSPI_INTR_TX_UNDERRUN 0x08 /* TxFIFO was underrun */ -#define XSPI_INTR_RX_FULL 0x10 /* RxFIFO is full */ -#define XSPI_INTR_RX_OVERRUN 0x20 /* RxFIFO was overrun */ - -#define XIPIF_V123B_RESETR_OFFSET 0x40 /* IPIF reset register */ -#define XIPIF_V123B_RESET_MASK 0x0a /* the value to write */ - -struct xilinx_spi { - /* bitbang has to be first */ - struct spi_bitbang bitbang; - struct completion done; - - void __iomem *regs; /* virt. address of the control registers */ - - u32 irq; - - u32 speed_hz; /* SCK has a fixed frequency of speed_hz Hz */ - - u8 *rx_ptr; /* pointer in the Tx buffer */ - const u8 *tx_ptr; /* pointer in the Rx buffer */ - int remaining_bytes; /* the number of bytes left to transfer */ -}; - -static void xspi_init_hw(void __iomem *regs_base) -{ - /* Reset the SPI device */ - out_be32(regs_base + XIPIF_V123B_RESETR_OFFSET, - XIPIF_V123B_RESET_MASK); - /* Disable all the interrupts just in case */ - out_be32(regs_base + XIPIF_V123B_IIER_OFFSET, 0); - /* Enable the global IPIF interrupt */ - out_be32(regs_base + XIPIF_V123B_DGIER_OFFSET, - XIPIF_V123B_GINTR_ENABLE); - /* Deselect the slave on the SPI bus */ - out_be32(regs_base + XSPI_SSR_OFFSET, 0xffff); - /* Disable the transmitter, enable Manual Slave Select Assertion, - * put SPI controller into master mode, and enable it */ - out_be16(regs_base + XSPI_CR_OFFSET, - XSPI_CR_TRANS_INHIBIT | XSPI_CR_MANUAL_SSELECT - | XSPI_CR_MASTER_MODE | XSPI_CR_ENABLE); -} - -static void xilinx_spi_chipselect(struct spi_device *spi, int is_on) -{ - struct xilinx_spi *xspi = spi_master_get_devdata(spi->master); - - if (is_on == BITBANG_CS_INACTIVE) { - /* Deselect the slave on the SPI bus */ - out_be32(xspi->regs + XSPI_SSR_OFFSET, 0xffff); - } else if (is_on == BITBANG_CS_ACTIVE) { - /* Set the SPI clock phase and polarity */ - u16 cr = in_be16(xspi->regs + XSPI_CR_OFFSET) - & ~XSPI_CR_MODE_MASK; - if (spi->mode & SPI_CPHA) - cr |= XSPI_CR_CPHA; - if (spi->mode & SPI_CPOL) - cr |= XSPI_CR_CPOL; - out_be16(xspi->regs + XSPI_CR_OFFSET, cr); - - /* We do not check spi->max_speed_hz here as the SPI clock - * frequency is not software programmable (the IP block design - * parameter) - */ - - /* Activate the chip select */ - out_be32(xspi->regs + XSPI_SSR_OFFSET, - ~(0x0001 << spi->chip_select)); - } -} - -/* spi_bitbang requires custom setup_transfer() to be defined if there is a - * custom txrx_bufs(). We have nothing to setup here as the SPI IP block - * supports just 8 bits per word, and SPI clock can't be changed in software. - * Check for 8 bits per word. Chip select delay calculations could be - * added here as soon as bitbang_work() can be made aware of the delay value. - */ -static int xilinx_spi_setup_transfer(struct spi_device *spi, - struct spi_transfer *t) -{ - u8 bits_per_word; - u32 hz; - struct xilinx_spi *xspi = spi_master_get_devdata(spi->master); - - bits_per_word = (t) ? t->bits_per_word : spi->bits_per_word; - hz = (t) ? t->speed_hz : spi->max_speed_hz; - if (bits_per_word != 8) { - dev_err(&spi->dev, "%s, unsupported bits_per_word=%d\n", - __FUNCTION__, bits_per_word); - return -EINVAL; - } - - if (hz && xspi->speed_hz > hz) { - dev_err(&spi->dev, "%s, unsupported clock rate %uHz\n", - __FUNCTION__, hz); - return -EINVAL; - } - - return 0; -} - -/* the spi->mode bits understood by this driver: */ -#define MODEBITS (SPI_CPOL | SPI_CPHA) - -static int xilinx_spi_setup(struct spi_device *spi) -{ - struct spi_bitbang *bitbang; - struct xilinx_spi *xspi; - int retval; - - xspi = spi_master_get_devdata(spi->master); - bitbang = &xspi->bitbang; - - if (!spi->bits_per_word) - spi->bits_per_word = 8; - - if (spi->mode & ~MODEBITS) { - dev_err(&spi->dev, "%s, unsupported mode bits %x\n", - __FUNCTION__, spi->mode & ~MODEBITS); - return -EINVAL; - } - - retval = xilinx_spi_setup_transfer(spi, NULL); - if (retval < 0) - return retval; - - dev_dbg(&spi->dev, "%s, mode %d, %u bits/w, %u nsec/bit\n", - __FUNCTION__, spi->mode & MODEBITS, spi->bits_per_word, 0); - - return 0; -} - -static void xilinx_spi_fill_tx_fifo(struct xilinx_spi *xspi) -{ - u8 sr; - - /* Fill the Tx FIFO with as many bytes as possible */ - sr = in_8(xspi->regs + XSPI_SR_OFFSET); - while ((sr & XSPI_SR_TX_FULL_MASK) == 0 && xspi->remaining_bytes > 0) { - if (xspi->tx_ptr) { - out_8(xspi->regs + XSPI_TXD_OFFSET, *xspi->tx_ptr++); - } else { - out_8(xspi->regs + XSPI_TXD_OFFSET, 0); - } - xspi->remaining_bytes--; - sr = in_8(xspi->regs + XSPI_SR_OFFSET); - } -} - -static int xilinx_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t) -{ - struct xilinx_spi *xspi = spi_master_get_devdata(spi->master); - u32 ipif_ier; - u16 cr; - - /* We get here with transmitter inhibited */ - - xspi->tx_ptr = t->tx_buf; - xspi->rx_ptr = t->rx_buf; - xspi->remaining_bytes = t->len; - INIT_COMPLETION(xspi->done); - - xilinx_spi_fill_tx_fifo(xspi); - - /* Enable the transmit empty interrupt, which we use to determine - * progress on the transmission. - */ - ipif_ier = in_be32(xspi->regs + XIPIF_V123B_IIER_OFFSET); - out_be32(xspi->regs + XIPIF_V123B_IIER_OFFSET, - ipif_ier | XSPI_INTR_TX_EMPTY); - - /* Start the transfer by not inhibiting the transmitter any longer */ - cr = in_be16(xspi->regs + XSPI_CR_OFFSET) & ~XSPI_CR_TRANS_INHIBIT; - out_be16(xspi->regs + XSPI_CR_OFFSET, cr); - - wait_for_completion(&xspi->done); - - /* Disable the transmit empty interrupt */ - out_be32(xspi->regs + XIPIF_V123B_IIER_OFFSET, ipif_ier); - - return t->len - xspi->remaining_bytes; -} - - -/* This driver supports single master mode only. Hence Tx FIFO Empty - * is the only interrupt we care about. - * Receive FIFO Overrun, Transmit FIFO Underrun, Mode Fault, and Slave Mode - * Fault are not to happen. - */ -static irqreturn_t xilinx_spi_irq(int irq, void *dev_id) -{ - struct xilinx_spi *xspi = dev_id; - u32 ipif_isr; - - /* Get the IPIF interrupts, and clear them immediately */ - ipif_isr = in_be32(xspi->regs + XIPIF_V123B_IISR_OFFSET); - out_be32(xspi->regs + XIPIF_V123B_IISR_OFFSET, ipif_isr); - - if (ipif_isr & XSPI_INTR_TX_EMPTY) { /* Transmission completed */ - u16 cr; - u8 sr; - - /* A transmit has just completed. Process received data and - * check for more data to transmit. Always inhibit the - * transmitter while the Isr refills the transmit register/FIFO, - * or make sure it is stopped if we're done. - */ - cr = in_be16(xspi->regs + XSPI_CR_OFFSET); - out_be16(xspi->regs + XSPI_CR_OFFSET, - cr | XSPI_CR_TRANS_INHIBIT); - - /* Read out all the data from the Rx FIFO */ - sr = in_8(xspi->regs + XSPI_SR_OFFSET); - while ((sr & XSPI_SR_RX_EMPTY_MASK) == 0) { - u8 data; - - data = in_8(xspi->regs + XSPI_RXD_OFFSET); - if (xspi->rx_ptr) { - *xspi->rx_ptr++ = data; - } - sr = in_8(xspi->regs + XSPI_SR_OFFSET); - } - - /* See if there is more data to send */ - if (xspi->remaining_bytes > 0) { - xilinx_spi_fill_tx_fifo(xspi); - /* Start the transfer by not inhibiting the - * transmitter any longer - */ - out_be16(xspi->regs + XSPI_CR_OFFSET, cr); - } else { - /* No more data to send. - * Indicate the transfer is completed. - */ - complete(&xspi->done); - } - } - - return IRQ_HANDLED; -} - -static int __init xilinx_spi_probe(struct platform_device *dev) -{ - int ret = 0; - struct spi_master *master; - struct xilinx_spi *xspi; - struct xspi_platform_data *pdata; - struct resource *r; - - /* Get resources(memory, IRQ) associated with the device */ - master = spi_alloc_master(&dev->dev, sizeof(struct xilinx_spi)); - - if (master == NULL) { - return -ENOMEM; - } - - platform_set_drvdata(dev, master); - pdata = dev->dev.platform_data; - - if (pdata == NULL) { - ret = -ENODEV; - goto put_master; - } - - r = platform_get_resource(dev, IORESOURCE_MEM, 0); - if (r == NULL) { - ret = -ENODEV; - goto put_master; - } - - xspi = spi_master_get_devdata(master); - xspi->bitbang.master = spi_master_get(master); - xspi->bitbang.chipselect = xilinx_spi_chipselect; - xspi->bitbang.setup_transfer = xilinx_spi_setup_transfer; - xspi->bitbang.txrx_bufs = xilinx_spi_txrx_bufs; - xspi->bitbang.master->setup = xilinx_spi_setup; - init_completion(&xspi->done); - - if (!request_mem_region(r->start, - r->end - r->start + 1, XILINX_SPI_NAME)) { - ret = -ENXIO; - goto put_master; - } - - xspi->regs = ioremap(r->start, r->end - r->start + 1); - if (xspi->regs == NULL) { - ret = -ENOMEM; - goto put_master; - } - - xspi->irq = platform_get_irq(dev, 0); - if (xspi->irq < 0) { - ret = -ENXIO; - goto unmap_io; - } - - master->bus_num = pdata->bus_num; - master->num_chipselect = pdata->num_chipselect; - xspi->speed_hz = pdata->speed_hz; - - /* SPI controller initializations */ - xspi_init_hw(xspi->regs); - - /* Register for SPI Interrupt */ - ret = request_irq(xspi->irq, xilinx_spi_irq, 0, XILINX_SPI_NAME, xspi); - if (ret != 0) - goto unmap_io; - - ret = spi_bitbang_start(&xspi->bitbang); - if (ret != 0) { - dev_err(&dev->dev, "spi_bitbang_start FAILED\n"); - goto free_irq; - } - - dev_info(&dev->dev, "at 0x%08X mapped to 0x%08X, irq=%d\n", - r->start, (u32)xspi->regs, xspi->irq); - - return ret; - -free_irq: - free_irq(xspi->irq, xspi); -unmap_io: - iounmap(xspi->regs); -put_master: - spi_master_put(master); - return ret; -} - -static int __devexit xilinx_spi_remove(struct platform_device *dev) -{ - struct xilinx_spi *xspi; - struct spi_master *master; - - master = platform_get_drvdata(dev); - xspi = spi_master_get_devdata(master); - - spi_bitbang_stop(&xspi->bitbang); - free_irq(xspi->irq, xspi); - iounmap(xspi->regs); - platform_set_drvdata(dev, 0); - spi_master_put(xspi->bitbang.master); - - return 0; -} - -static struct platform_driver xilinx_spi_driver = { - .probe = xilinx_spi_probe, - .remove = __devexit_p(xilinx_spi_remove), - .driver = { - .name = XILINX_SPI_NAME, - .owner = THIS_MODULE, - }, -}; - -static int __init xilinx_spi_init(void) -{ - return platform_driver_register(&xilinx_spi_driver); -} -module_init(xilinx_spi_init); - -static void __exit xilinx_spi_exit(void) -{ - platform_driver_unregister(&xilinx_spi_driver); -} -module_exit(xilinx_spi_exit); - -MODULE_AUTHOR("MontaVista Software, Inc. <source@mvista.com>"); -MODULE_DESCRIPTION("Xilinx SPI driver"); -MODULE_LICENSE("GPL"); |