diff options
Diffstat (limited to 'drivers/spi/mpc52xx_spi.c')
| -rw-r--r-- | drivers/spi/mpc52xx_spi.c | 580 |
1 files changed, 0 insertions, 580 deletions
diff --git a/drivers/spi/mpc52xx_spi.c b/drivers/spi/mpc52xx_spi.c deleted file mode 100644 index ec9f0b1bf86..00000000000 --- a/drivers/spi/mpc52xx_spi.c +++ /dev/null @@ -1,580 +0,0 @@ -/* - * MPC52xx SPI bus driver. - * - * Copyright (C) 2008 Secret Lab Technologies Ltd. - * - * This file is released under the GPLv2 - * - * This is the driver for the MPC5200's dedicated SPI controller. - * - * Note: this driver does not support the MPC5200 PSC in SPI mode. For - * that driver see drivers/spi/mpc52xx_psc_spi.c - */ - -#include <linux/module.h> -#include <linux/init.h> -#include <linux/errno.h> -#include <linux/of_platform.h> -#include <linux/interrupt.h> -#include <linux/delay.h> -#include <linux/spi/spi.h> -#include <linux/io.h> -#include <linux/of_gpio.h> -#include <linux/slab.h> -#include <asm/time.h> -#include <asm/mpc52xx.h> - -MODULE_AUTHOR("Grant Likely <grant.likely@secretlab.ca>"); -MODULE_DESCRIPTION("MPC52xx SPI (non-PSC) Driver"); -MODULE_LICENSE("GPL"); - -/* Register offsets */ -#define SPI_CTRL1 0x00 -#define SPI_CTRL1_SPIE (1 << 7) -#define SPI_CTRL1_SPE (1 << 6) -#define SPI_CTRL1_MSTR (1 << 4) -#define SPI_CTRL1_CPOL (1 << 3) -#define SPI_CTRL1_CPHA (1 << 2) -#define SPI_CTRL1_SSOE (1 << 1) -#define SPI_CTRL1_LSBFE (1 << 0) - -#define SPI_CTRL2 0x01 -#define SPI_BRR 0x04 - -#define SPI_STATUS 0x05 -#define SPI_STATUS_SPIF (1 << 7) -#define SPI_STATUS_WCOL (1 << 6) -#define SPI_STATUS_MODF (1 << 4) - -#define SPI_DATA 0x09 -#define SPI_PORTDATA 0x0d -#define SPI_DATADIR 0x10 - -/* FSM state return values */ -#define FSM_STOP 0 /* Nothing more for the state machine to */ - /* do. If something interesting happens */ - /* then an IRQ will be received */ -#define FSM_POLL 1 /* need to poll for completion, an IRQ is */ - /* not expected */ -#define FSM_CONTINUE 2 /* Keep iterating the state machine */ - -/* Driver internal data */ -struct mpc52xx_spi { - struct spi_master *master; - void __iomem *regs; - int irq0; /* MODF irq */ - int irq1; /* SPIF irq */ - unsigned int ipb_freq; - - /* Statistics; not used now, but will be reintroduced for debugfs */ - int msg_count; - int wcol_count; - int wcol_ticks; - u32 wcol_tx_timestamp; - int modf_count; - int byte_count; - - struct list_head queue; /* queue of pending messages */ - spinlock_t lock; - struct work_struct work; - - /* Details of current transfer (length, and buffer pointers) */ - struct spi_message *message; /* current message */ - struct spi_transfer *transfer; /* current transfer */ - int (*state)(int irq, struct mpc52xx_spi *ms, u8 status, u8 data); - int len; - int timestamp; - u8 *rx_buf; - const u8 *tx_buf; - int cs_change; - int gpio_cs_count; - unsigned int *gpio_cs; -}; - -/* - * CS control function - */ -static void mpc52xx_spi_chipsel(struct mpc52xx_spi *ms, int value) -{ - int cs; - - if (ms->gpio_cs_count > 0) { - cs = ms->message->spi->chip_select; - gpio_set_value(ms->gpio_cs[cs], value ? 0 : 1); - } else - out_8(ms->regs + SPI_PORTDATA, value ? 0 : 0x08); -} - -/* - * Start a new transfer. This is called both by the idle state - * for the first transfer in a message, and by the wait state when the - * previous transfer in a message is complete. - */ -static void mpc52xx_spi_start_transfer(struct mpc52xx_spi *ms) -{ - ms->rx_buf = ms->transfer->rx_buf; - ms->tx_buf = ms->transfer->tx_buf; - ms->len = ms->transfer->len; - - /* Activate the chip select */ - if (ms->cs_change) - mpc52xx_spi_chipsel(ms, 1); - ms->cs_change = ms->transfer->cs_change; - - /* Write out the first byte */ - ms->wcol_tx_timestamp = get_tbl(); - if (ms->tx_buf) - out_8(ms->regs + SPI_DATA, *ms->tx_buf++); - else - out_8(ms->regs + SPI_DATA, 0); -} - -/* Forward declaration of state handlers */ -static int mpc52xx_spi_fsmstate_transfer(int irq, struct mpc52xx_spi *ms, - u8 status, u8 data); -static int mpc52xx_spi_fsmstate_wait(int irq, struct mpc52xx_spi *ms, - u8 status, u8 data); - -/* - * IDLE state - * - * No transfers are in progress; if another transfer is pending then retrieve - * it and kick it off. Otherwise, stop processing the state machine - */ -static int -mpc52xx_spi_fsmstate_idle(int irq, struct mpc52xx_spi *ms, u8 status, u8 data) -{ - struct spi_device *spi; - int spr, sppr; - u8 ctrl1; - - if (status && (irq != NO_IRQ)) - dev_err(&ms->master->dev, "spurious irq, status=0x%.2x\n", - status); - - /* Check if there is another transfer waiting. */ - if (list_empty(&ms->queue)) - return FSM_STOP; - - /* get the head of the queue */ - ms->message = list_first_entry(&ms->queue, struct spi_message, queue); - list_del_init(&ms->message->queue); - - /* Setup the controller parameters */ - ctrl1 = SPI_CTRL1_SPIE | SPI_CTRL1_SPE | SPI_CTRL1_MSTR; - spi = ms->message->spi; - if (spi->mode & SPI_CPHA) - ctrl1 |= SPI_CTRL1_CPHA; - if (spi->mode & SPI_CPOL) - ctrl1 |= SPI_CTRL1_CPOL; - if (spi->mode & SPI_LSB_FIRST) - ctrl1 |= SPI_CTRL1_LSBFE; - out_8(ms->regs + SPI_CTRL1, ctrl1); - - /* Setup the controller speed */ - /* minimum divider is '2'. Also, add '1' to force rounding the - * divider up. */ - sppr = ((ms->ipb_freq / ms->message->spi->max_speed_hz) + 1) >> 1; - spr = 0; - if (sppr < 1) - sppr = 1; - while (((sppr - 1) & ~0x7) != 0) { - sppr = (sppr + 1) >> 1; /* add '1' to force rounding up */ - spr++; - } - sppr--; /* sppr quantity in register is offset by 1 */ - if (spr > 7) { - /* Don't overrun limits of SPI baudrate register */ - spr = 7; - sppr = 7; - } - out_8(ms->regs + SPI_BRR, sppr << 4 | spr); /* Set speed */ - - ms->cs_change = 1; - ms->transfer = container_of(ms->message->transfers.next, - struct spi_transfer, transfer_list); - - mpc52xx_spi_start_transfer(ms); - ms->state = mpc52xx_spi_fsmstate_transfer; - - return FSM_CONTINUE; -} - -/* - * TRANSFER state - * - * In the middle of a transfer. If the SPI core has completed processing - * a byte, then read out the received data and write out the next byte - * (unless this transfer is finished; in which case go on to the wait - * state) - */ -static int mpc52xx_spi_fsmstate_transfer(int irq, struct mpc52xx_spi *ms, - u8 status, u8 data) -{ - if (!status) - return ms->irq0 ? FSM_STOP : FSM_POLL; - - if (status & SPI_STATUS_WCOL) { - /* The SPI controller is stoopid. At slower speeds, it may - * raise the SPIF flag before the state machine is actually - * finished, which causes a collision (internal to the state - * machine only). The manual recommends inserting a delay - * between receiving the interrupt and sending the next byte, - * but it can also be worked around simply by retrying the - * transfer which is what we do here. */ - ms->wcol_count++; - ms->wcol_ticks += get_tbl() - ms->wcol_tx_timestamp; - ms->wcol_tx_timestamp = get_tbl(); - data = 0; - if (ms->tx_buf) - data = *(ms->tx_buf - 1); - out_8(ms->regs + SPI_DATA, data); /* try again */ - return FSM_CONTINUE; - } else if (status & SPI_STATUS_MODF) { - ms->modf_count++; - dev_err(&ms->master->dev, "mode fault\n"); - mpc52xx_spi_chipsel(ms, 0); - ms->message->status = -EIO; - ms->message->complete(ms->message->context); - ms->state = mpc52xx_spi_fsmstate_idle; - return FSM_CONTINUE; - } - - /* Read data out of the spi device */ - ms->byte_count++; - if (ms->rx_buf) - *ms->rx_buf++ = data; - - /* Is the transfer complete? */ - ms->len--; - if (ms->len == 0) { - ms->timestamp = get_tbl(); - ms->timestamp += ms->transfer->delay_usecs * tb_ticks_per_usec; - ms->state = mpc52xx_spi_fsmstate_wait; - return FSM_CONTINUE; - } - - /* Write out the next byte */ - ms->wcol_tx_timestamp = get_tbl(); - if (ms->tx_buf) - out_8(ms->regs + SPI_DATA, *ms->tx_buf++); - else - out_8(ms->regs + SPI_DATA, 0); - - return FSM_CONTINUE; -} - -/* - * WAIT state - * - * A transfer has completed; need to wait for the delay period to complete - * before starting the next transfer - */ -static int -mpc52xx_spi_fsmstate_wait(int irq, struct mpc52xx_spi *ms, u8 status, u8 data) -{ - if (status && irq) - dev_err(&ms->master->dev, "spurious irq, status=0x%.2x\n", - status); - - if (((int)get_tbl()) - ms->timestamp < 0) - return FSM_POLL; - - ms->message->actual_length += ms->transfer->len; - - /* Check if there is another transfer in this message. If there - * aren't then deactivate CS, notify sender, and drop back to idle - * to start the next message. */ - if (ms->transfer->transfer_list.next == &ms->message->transfers) { - ms->msg_count++; - mpc52xx_spi_chipsel(ms, 0); - ms->message->status = 0; - ms->message->complete(ms->message->context); - ms->state = mpc52xx_spi_fsmstate_idle; - return FSM_CONTINUE; - } - - /* There is another transfer; kick it off */ - - if (ms->cs_change) - mpc52xx_spi_chipsel(ms, 0); - - ms->transfer = container_of(ms->transfer->transfer_list.next, - struct spi_transfer, transfer_list); - mpc52xx_spi_start_transfer(ms); - ms->state = mpc52xx_spi_fsmstate_transfer; - return FSM_CONTINUE; -} - -/** - * mpc52xx_spi_fsm_process - Finite State Machine iteration function - * @irq: irq number that triggered the FSM or 0 for polling - * @ms: pointer to mpc52xx_spi driver data - */ -static void mpc52xx_spi_fsm_process(int irq, struct mpc52xx_spi *ms) -{ - int rc = FSM_CONTINUE; - u8 status, data; - - while (rc == FSM_CONTINUE) { - /* Interrupt cleared by read of STATUS followed by - * read of DATA registers */ - status = in_8(ms->regs + SPI_STATUS); - data = in_8(ms->regs + SPI_DATA); - rc = ms->state(irq, ms, status, data); - } - - if (rc == FSM_POLL) - schedule_work(&ms->work); -} - -/** - * mpc52xx_spi_irq - IRQ handler - */ -static irqreturn_t mpc52xx_spi_irq(int irq, void *_ms) -{ - struct mpc52xx_spi *ms = _ms; - spin_lock(&ms->lock); - mpc52xx_spi_fsm_process(irq, ms); - spin_unlock(&ms->lock); - return IRQ_HANDLED; -} - -/** - * mpc52xx_spi_wq - Workqueue function for polling the state machine - */ -static void mpc52xx_spi_wq(struct work_struct *work) -{ - struct mpc52xx_spi *ms = container_of(work, struct mpc52xx_spi, work); - unsigned long flags; - - spin_lock_irqsave(&ms->lock, flags); - mpc52xx_spi_fsm_process(0, ms); - spin_unlock_irqrestore(&ms->lock, flags); -} - -/* - * spi_master ops - */ - -static int mpc52xx_spi_setup(struct spi_device *spi) -{ - if (spi->bits_per_word % 8) - return -EINVAL; - - if (spi->mode & ~(SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST)) - return -EINVAL; - - if (spi->chip_select >= spi->master->num_chipselect) - return -EINVAL; - - return 0; -} - -static int mpc52xx_spi_transfer(struct spi_device *spi, struct spi_message *m) -{ - struct mpc52xx_spi *ms = spi_master_get_devdata(spi->master); - unsigned long flags; - - m->actual_length = 0; - m->status = -EINPROGRESS; - - spin_lock_irqsave(&ms->lock, flags); - list_add_tail(&m->queue, &ms->queue); - spin_unlock_irqrestore(&ms->lock, flags); - schedule_work(&ms->work); - - return 0; -} - -/* - * OF Platform Bus Binding - */ -static int __devinit mpc52xx_spi_probe(struct platform_device *op, - const struct of_device_id *match) -{ - struct spi_master *master; - struct mpc52xx_spi *ms; - void __iomem *regs; - u8 ctrl1; - int rc, i = 0; - int gpio_cs; - - /* MMIO registers */ - dev_dbg(&op->dev, "probing mpc5200 SPI device\n"); - regs = of_iomap(op->dev.of_node, 0); - if (!regs) - return -ENODEV; - - /* initialize the device */ - ctrl1 = SPI_CTRL1_SPIE | SPI_CTRL1_SPE | SPI_CTRL1_MSTR; - out_8(regs + SPI_CTRL1, ctrl1); - out_8(regs + SPI_CTRL2, 0x0); - out_8(regs + SPI_DATADIR, 0xe); /* Set output pins */ - out_8(regs + SPI_PORTDATA, 0x8); /* Deassert /SS signal */ - - /* Clear the status register and re-read it to check for a MODF - * failure. This driver cannot currently handle multiple masters - * on the SPI bus. This fault will also occur if the SPI signals - * are not connected to any pins (port_config setting) */ - in_8(regs + SPI_STATUS); - out_8(regs + SPI_CTRL1, ctrl1); - - in_8(regs + SPI_DATA); - if (in_8(regs + SPI_STATUS) & SPI_STATUS_MODF) { - dev_err(&op->dev, "mode fault; is port_config correct?\n"); - rc = -EIO; - goto err_init; - } - - dev_dbg(&op->dev, "allocating spi_master struct\n"); - master = spi_alloc_master(&op->dev, sizeof *ms); - if (!master) { - rc = -ENOMEM; - goto err_alloc; - } - - master->bus_num = -1; - master->setup = mpc52xx_spi_setup; - master->transfer = mpc52xx_spi_transfer; - master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST; - master->dev.of_node = op->dev.of_node; - - dev_set_drvdata(&op->dev, master); - - ms = spi_master_get_devdata(master); - ms->master = master; - ms->regs = regs; - ms->irq0 = irq_of_parse_and_map(op->dev.of_node, 0); - ms->irq1 = irq_of_parse_and_map(op->dev.of_node, 1); - ms->state = mpc52xx_spi_fsmstate_idle; - ms->ipb_freq = mpc5xxx_get_bus_frequency(op->dev.of_node); - ms->gpio_cs_count = of_gpio_count(op->dev.of_node); - if (ms->gpio_cs_count > 0) { - master->num_chipselect = ms->gpio_cs_count; - ms->gpio_cs = kmalloc(ms->gpio_cs_count * sizeof(unsigned int), - GFP_KERNEL); - if (!ms->gpio_cs) { - rc = -ENOMEM; - goto err_alloc; - } - - for (i = 0; i < ms->gpio_cs_count; i++) { - gpio_cs = of_get_gpio(op->dev.of_node, i); - if (gpio_cs < 0) { - dev_err(&op->dev, - "could not parse the gpio field " - "in oftree\n"); - rc = -ENODEV; - goto err_gpio; - } - - rc = gpio_request(gpio_cs, dev_name(&op->dev)); - if (rc) { - dev_err(&op->dev, - "can't request spi cs gpio #%d " - "on gpio line %d\n", i, gpio_cs); - goto err_gpio; - } - - gpio_direction_output(gpio_cs, 1); - ms->gpio_cs[i] = gpio_cs; - } - } else { - master->num_chipselect = 1; - } - - spin_lock_init(&ms->lock); - INIT_LIST_HEAD(&ms->queue); - INIT_WORK(&ms->work, mpc52xx_spi_wq); - - /* Decide if interrupts can be used */ - if (ms->irq0 && ms->irq1) { - rc = request_irq(ms->irq0, mpc52xx_spi_irq, 0, - "mpc5200-spi-modf", ms); - rc |= request_irq(ms->irq1, mpc52xx_spi_irq, 0, - "mpc5200-spi-spif", ms); - if (rc) { - free_irq(ms->irq0, ms); - free_irq(ms->irq1, ms); - ms->irq0 = ms->irq1 = 0; - } - } else { - /* operate in polled mode */ - ms->irq0 = ms->irq1 = 0; - } - - if (!ms->irq0) - dev_info(&op->dev, "using polled mode\n"); - - dev_dbg(&op->dev, "registering spi_master struct\n"); - rc = spi_register_master(master); - if (rc) - goto err_register; - - dev_info(&ms->master->dev, "registered MPC5200 SPI bus\n"); - - return rc; - - err_register: - dev_err(&ms->master->dev, "initialization failed\n"); - spi_master_put(master); - err_gpio: - while (i-- > 0) - gpio_free(ms->gpio_cs[i]); - - kfree(ms->gpio_cs); - err_alloc: - err_init: - iounmap(regs); - return rc; -} - -static int __devexit mpc52xx_spi_remove(struct platform_device *op) -{ - struct spi_master *master = dev_get_drvdata(&op->dev); - struct mpc52xx_spi *ms = spi_master_get_devdata(master); - int i; - - free_irq(ms->irq0, ms); - free_irq(ms->irq1, ms); - - for (i = 0; i < ms->gpio_cs_count; i++) - gpio_free(ms->gpio_cs[i]); - - kfree(ms->gpio_cs); - spi_unregister_master(master); - spi_master_put(master); - iounmap(ms->regs); - - return 0; -} - -static const struct of_device_id mpc52xx_spi_match[] __devinitconst = { - { .compatible = "fsl,mpc5200-spi", }, - {} -}; -MODULE_DEVICE_TABLE(of, mpc52xx_spi_match); - -static struct of_platform_driver mpc52xx_spi_of_driver = { - .driver = { - .name = "mpc52xx-spi", - .owner = THIS_MODULE, - .of_match_table = mpc52xx_spi_match, - }, - .probe = mpc52xx_spi_probe, - .remove = __exit_p(mpc52xx_spi_remove), -}; - -static int __init mpc52xx_spi_init(void) -{ - return of_register_platform_driver(&mpc52xx_spi_of_driver); -} -module_init(mpc52xx_spi_init); - -static void __exit mpc52xx_spi_exit(void) -{ - of_unregister_platform_driver(&mpc52xx_spi_of_driver); -} -module_exit(mpc52xx_spi_exit); - |