+++ /dev/null
-/*
- * TXx9 SPI controller driver.
- *
- * Based on linux/arch/mips/tx4938/toshiba_rbtx4938/spi_txx9.c
- * Copyright (C) 2000-2001 Toshiba Corporation
- *
- * 2003-2005 (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.
- *
- * Support for TX4938 in 2.6 - Manish Lachwani (mlachwani@mvista.com)
- *
- * Convert to generic SPI framework - Atsushi Nemoto (anemo@mba.ocn.ne.jp)
- */
-#include <linux/init.h>
-#include <linux/delay.h>
-#include <linux/errno.h>
-#include <linux/interrupt.h>
-#include <linux/platform_device.h>
-#include <linux/sched.h>
-#include <linux/spinlock.h>
-#include <linux/workqueue.h>
-#include <linux/spi/spi.h>
-#include <linux/err.h>
-#include <linux/clk.h>
-#include <linux/io.h>
-#include <linux/module.h>
-#include <linux/gpio/machine.h>
-#include <linux/gpio/consumer.h>
-
-
-#define SPI_FIFO_SIZE 4
-#define SPI_MAX_DIVIDER 0xff /* Max. value for SPCR1.SER */
-#define SPI_MIN_DIVIDER 1 /* Min. value for SPCR1.SER */
-
-#define TXx9_SPMCR 0x00
-#define TXx9_SPCR0 0x04
-#define TXx9_SPCR1 0x08
-#define TXx9_SPFS 0x0c
-#define TXx9_SPSR 0x14
-#define TXx9_SPDR 0x18
-
-/* SPMCR : SPI Master Control */
-#define TXx9_SPMCR_OPMODE 0xc0
-#define TXx9_SPMCR_CONFIG 0x40
-#define TXx9_SPMCR_ACTIVE 0x80
-#define TXx9_SPMCR_SPSTP 0x02
-#define TXx9_SPMCR_BCLR 0x01
-
-/* SPCR0 : SPI Control 0 */
-#define TXx9_SPCR0_TXIFL_MASK 0xc000
-#define TXx9_SPCR0_RXIFL_MASK 0x3000
-#define TXx9_SPCR0_SIDIE 0x0800
-#define TXx9_SPCR0_SOEIE 0x0400
-#define TXx9_SPCR0_RBSIE 0x0200
-#define TXx9_SPCR0_TBSIE 0x0100
-#define TXx9_SPCR0_IFSPSE 0x0010
-#define TXx9_SPCR0_SBOS 0x0004
-#define TXx9_SPCR0_SPHA 0x0002
-#define TXx9_SPCR0_SPOL 0x0001
-
-/* SPSR : SPI Status */
-#define TXx9_SPSR_TBSI 0x8000
-#define TXx9_SPSR_RBSI 0x4000
-#define TXx9_SPSR_TBS_MASK 0x3800
-#define TXx9_SPSR_RBS_MASK 0x0700
-#define TXx9_SPSR_SPOE 0x0080
-#define TXx9_SPSR_IFSD 0x0008
-#define TXx9_SPSR_SIDLE 0x0004
-#define TXx9_SPSR_STRDY 0x0002
-#define TXx9_SPSR_SRRDY 0x0001
-
-
-struct txx9spi {
- struct work_struct work;
- spinlock_t lock; /* protect 'queue' */
- struct list_head queue;
- wait_queue_head_t waitq;
- void __iomem *membase;
- int baseclk;
- struct clk *clk;
- struct gpio_desc *last_chipselect;
- int last_chipselect_val;
-};
-
-static u32 txx9spi_rd(struct txx9spi *c, int reg)
-{
- return __raw_readl(c->membase + reg);
-}
-static void txx9spi_wr(struct txx9spi *c, u32 val, int reg)
-{
- __raw_writel(val, c->membase + reg);
-}
-
-static void txx9spi_cs_func(struct spi_device *spi, struct txx9spi *c,
- int on, unsigned int cs_delay)
-{
- /*
- * The GPIO descriptor will track polarity inversion inside
- * gpiolib.
- */
- if (on) {
- /* deselect the chip with cs_change hint in last transfer */
- if (c->last_chipselect)
- gpiod_set_value(c->last_chipselect,
- !c->last_chipselect_val);
- c->last_chipselect = spi->cs_gpiod;
- c->last_chipselect_val = on;
- } else {
- c->last_chipselect = NULL;
- ndelay(cs_delay); /* CS Hold Time */
- }
- gpiod_set_value(spi->cs_gpiod, on);
- ndelay(cs_delay); /* CS Setup Time / CS Recovery Time */
-}
-
-static int txx9spi_setup(struct spi_device *spi)
-{
- struct txx9spi *c = spi_master_get_devdata(spi->master);
-
- if (!spi->max_speed_hz)
- return -EINVAL;
-
- /* deselect chip */
- spin_lock(&c->lock);
- txx9spi_cs_func(spi, c, 0, (NSEC_PER_SEC / 2) / spi->max_speed_hz);
- spin_unlock(&c->lock);
-
- return 0;
-}
-
-static irqreturn_t txx9spi_interrupt(int irq, void *dev_id)
-{
- struct txx9spi *c = dev_id;
-
- /* disable rx intr */
- txx9spi_wr(c, txx9spi_rd(c, TXx9_SPCR0) & ~TXx9_SPCR0_RBSIE,
- TXx9_SPCR0);
- wake_up(&c->waitq);
- return IRQ_HANDLED;
-}
-
-static void txx9spi_work_one(struct txx9spi *c, struct spi_message *m)
-{
- struct spi_device *spi = m->spi;
- struct spi_transfer *t;
- unsigned int cs_delay;
- unsigned int cs_change = 1;
- int status = 0;
- u32 mcr;
- u32 prev_speed_hz = 0;
- u8 prev_bits_per_word = 0;
-
- /* CS setup/hold/recovery time in nsec */
- cs_delay = 100 + (NSEC_PER_SEC / 2) / spi->max_speed_hz;
-
- mcr = txx9spi_rd(c, TXx9_SPMCR);
- if (unlikely((mcr & TXx9_SPMCR_OPMODE) == TXx9_SPMCR_ACTIVE)) {
- dev_err(&spi->dev, "Bad mode.\n");
- status = -EIO;
- goto exit;
- }
- mcr &= ~(TXx9_SPMCR_OPMODE | TXx9_SPMCR_SPSTP | TXx9_SPMCR_BCLR);
-
- /* enter config mode */
- txx9spi_wr(c, mcr | TXx9_SPMCR_CONFIG | TXx9_SPMCR_BCLR, TXx9_SPMCR);
- txx9spi_wr(c, TXx9_SPCR0_SBOS
- | ((spi->mode & SPI_CPOL) ? TXx9_SPCR0_SPOL : 0)
- | ((spi->mode & SPI_CPHA) ? TXx9_SPCR0_SPHA : 0)
- | 0x08,
- TXx9_SPCR0);
-
- list_for_each_entry(t, &m->transfers, transfer_list) {
- const void *txbuf = t->tx_buf;
- void *rxbuf = t->rx_buf;
- u32 data;
- unsigned int len = t->len;
- unsigned int wsize;
- u32 speed_hz = t->speed_hz;
- u8 bits_per_word = t->bits_per_word;
-
- wsize = bits_per_word >> 3; /* in bytes */
-
- if (prev_speed_hz != speed_hz
- || prev_bits_per_word != bits_per_word) {
- int n = DIV_ROUND_UP(c->baseclk, speed_hz) - 1;
-
- n = clamp(n, SPI_MIN_DIVIDER, SPI_MAX_DIVIDER);
- /* enter config mode */
- txx9spi_wr(c, mcr | TXx9_SPMCR_CONFIG | TXx9_SPMCR_BCLR,
- TXx9_SPMCR);
- txx9spi_wr(c, (n << 8) | bits_per_word, TXx9_SPCR1);
- /* enter active mode */
- txx9spi_wr(c, mcr | TXx9_SPMCR_ACTIVE, TXx9_SPMCR);
-
- prev_speed_hz = speed_hz;
- prev_bits_per_word = bits_per_word;
- }
-
- if (cs_change)
- txx9spi_cs_func(spi, c, 1, cs_delay);
- cs_change = t->cs_change;
- while (len) {
- unsigned int count = SPI_FIFO_SIZE;
- int i;
- u32 cr0;
-
- if (len < count * wsize)
- count = len / wsize;
- /* now tx must be idle... */
- while (!(txx9spi_rd(c, TXx9_SPSR) & TXx9_SPSR_SIDLE))
- cpu_relax();
- cr0 = txx9spi_rd(c, TXx9_SPCR0);
- cr0 &= ~TXx9_SPCR0_RXIFL_MASK;
- cr0 |= (count - 1) << 12;
- /* enable rx intr */
- cr0 |= TXx9_SPCR0_RBSIE;
- txx9spi_wr(c, cr0, TXx9_SPCR0);
- /* send */
- for (i = 0; i < count; i++) {
- if (txbuf) {
- data = (wsize == 1)
- ? *(const u8 *)txbuf
- : *(const u16 *)txbuf;
- txx9spi_wr(c, data, TXx9_SPDR);
- txbuf += wsize;
- } else
- txx9spi_wr(c, 0, TXx9_SPDR);
- }
- /* wait all rx data */
- wait_event(c->waitq,
- txx9spi_rd(c, TXx9_SPSR) & TXx9_SPSR_RBSI);
- /* receive */
- for (i = 0; i < count; i++) {
- data = txx9spi_rd(c, TXx9_SPDR);
- if (rxbuf) {
- if (wsize == 1)
- *(u8 *)rxbuf = data;
- else
- *(u16 *)rxbuf = data;
- rxbuf += wsize;
- }
- }
- len -= count * wsize;
- }
- m->actual_length += t->len;
- spi_transfer_delay_exec(t);
-
- if (!cs_change)
- continue;
- if (t->transfer_list.next == &m->transfers)
- break;
- /* sometimes a short mid-message deselect of the chip
- * may be needed to terminate a mode or command
- */
- txx9spi_cs_func(spi, c, 0, cs_delay);
- }
-
-exit:
- m->status = status;
- if (m->complete)
- m->complete(m->context);
-
- /* normally deactivate chipselect ... unless no error and
- * cs_change has hinted that the next message will probably
- * be for this chip too.
- */
- if (!(status == 0 && cs_change))
- txx9spi_cs_func(spi, c, 0, cs_delay);
-
- /* enter config mode */
- txx9spi_wr(c, mcr | TXx9_SPMCR_CONFIG | TXx9_SPMCR_BCLR, TXx9_SPMCR);
-}
-
-static void txx9spi_work(struct work_struct *work)
-{
- struct txx9spi *c = container_of(work, struct txx9spi, work);
- unsigned long flags;
-
- spin_lock_irqsave(&c->lock, flags);
- while (!list_empty(&c->queue)) {
- struct spi_message *m;
-
- m = container_of(c->queue.next, struct spi_message, queue);
- list_del_init(&m->queue);
- spin_unlock_irqrestore(&c->lock, flags);
-
- txx9spi_work_one(c, m);
-
- spin_lock_irqsave(&c->lock, flags);
- }
- spin_unlock_irqrestore(&c->lock, flags);
-}
-
-static int txx9spi_transfer(struct spi_device *spi, struct spi_message *m)
-{
- struct spi_master *master = spi->master;
- struct txx9spi *c = spi_master_get_devdata(master);
- struct spi_transfer *t;
- unsigned long flags;
-
- m->actual_length = 0;
-
- /* check each transfer's parameters */
- list_for_each_entry(t, &m->transfers, transfer_list) {
- if (!t->tx_buf && !t->rx_buf && t->len)
- return -EINVAL;
- }
-
- spin_lock_irqsave(&c->lock, flags);
- list_add_tail(&m->queue, &c->queue);
- schedule_work(&c->work);
- spin_unlock_irqrestore(&c->lock, flags);
-
- return 0;
-}
-
-/*
- * Chip select uses GPIO only, further the driver is using the chip select
- * numer (from the device tree "reg" property, and this can only come from
- * device tree since this i MIPS and there is no way to pass platform data) as
- * the GPIO number. As the platform has only one GPIO controller (the txx9 GPIO
- * chip) it is thus using the chip select number as an offset into that chip.
- * This chip has a maximum of 16 GPIOs 0..15 and this is what all platforms
- * register.
- *
- * We modernized this behaviour by explicitly converting that offset to an
- * offset on the GPIO chip using a GPIO descriptor machine table of the same
- * size as the txx9 GPIO chip with a 1-to-1 mapping of chip select to GPIO
- * offset.
- *
- * This is admittedly a hack, but it is countering the hack of using "reg" to
- * contain a GPIO offset when it should be using "cs-gpios" as the SPI bindings
- * state.
- */
-static struct gpiod_lookup_table txx9spi_cs_gpio_table = {
- .dev_id = "spi0",
- .table = {
- GPIO_LOOKUP_IDX("TXx9", 0, "cs", 0, GPIO_ACTIVE_LOW),
- GPIO_LOOKUP_IDX("TXx9", 1, "cs", 1, GPIO_ACTIVE_LOW),
- GPIO_LOOKUP_IDX("TXx9", 2, "cs", 2, GPIO_ACTIVE_LOW),
- GPIO_LOOKUP_IDX("TXx9", 3, "cs", 3, GPIO_ACTIVE_LOW),
- GPIO_LOOKUP_IDX("TXx9", 4, "cs", 4, GPIO_ACTIVE_LOW),
- GPIO_LOOKUP_IDX("TXx9", 5, "cs", 5, GPIO_ACTIVE_LOW),
- GPIO_LOOKUP_IDX("TXx9", 6, "cs", 6, GPIO_ACTIVE_LOW),
- GPIO_LOOKUP_IDX("TXx9", 7, "cs", 7, GPIO_ACTIVE_LOW),
- GPIO_LOOKUP_IDX("TXx9", 8, "cs", 8, GPIO_ACTIVE_LOW),
- GPIO_LOOKUP_IDX("TXx9", 9, "cs", 9, GPIO_ACTIVE_LOW),
- GPIO_LOOKUP_IDX("TXx9", 10, "cs", 10, GPIO_ACTIVE_LOW),
- GPIO_LOOKUP_IDX("TXx9", 11, "cs", 11, GPIO_ACTIVE_LOW),
- GPIO_LOOKUP_IDX("TXx9", 12, "cs", 12, GPIO_ACTIVE_LOW),
- GPIO_LOOKUP_IDX("TXx9", 13, "cs", 13, GPIO_ACTIVE_LOW),
- GPIO_LOOKUP_IDX("TXx9", 14, "cs", 14, GPIO_ACTIVE_LOW),
- GPIO_LOOKUP_IDX("TXx9", 15, "cs", 15, GPIO_ACTIVE_LOW),
- { },
- },
-};
-
-static int txx9spi_probe(struct platform_device *dev)
-{
- struct spi_master *master;
- struct txx9spi *c;
- struct resource *res;
- int ret = -ENODEV;
- u32 mcr;
- int irq;
-
- master = spi_alloc_master(&dev->dev, sizeof(*c));
- if (!master)
- return ret;
- c = spi_master_get_devdata(master);
- platform_set_drvdata(dev, master);
-
- INIT_WORK(&c->work, txx9spi_work);
- spin_lock_init(&c->lock);
- INIT_LIST_HEAD(&c->queue);
- init_waitqueue_head(&c->waitq);
-
- c->clk = devm_clk_get(&dev->dev, "spi-baseclk");
- if (IS_ERR(c->clk)) {
- ret = PTR_ERR(c->clk);
- c->clk = NULL;
- goto exit;
- }
- ret = clk_prepare_enable(c->clk);
- if (ret) {
- c->clk = NULL;
- goto exit;
- }
- c->baseclk = clk_get_rate(c->clk);
- master->min_speed_hz = DIV_ROUND_UP(c->baseclk, SPI_MAX_DIVIDER + 1);
- master->max_speed_hz = c->baseclk / (SPI_MIN_DIVIDER + 1);
-
- res = platform_get_resource(dev, IORESOURCE_MEM, 0);
- c->membase = devm_ioremap_resource(&dev->dev, res);
- if (IS_ERR(c->membase))
- goto exit_busy;
-
- /* enter config mode */
- mcr = txx9spi_rd(c, TXx9_SPMCR);
- mcr &= ~(TXx9_SPMCR_OPMODE | TXx9_SPMCR_SPSTP | TXx9_SPMCR_BCLR);
- txx9spi_wr(c, mcr | TXx9_SPMCR_CONFIG | TXx9_SPMCR_BCLR, TXx9_SPMCR);
-
- irq = platform_get_irq(dev, 0);
- if (irq < 0)
- goto exit_busy;
- ret = devm_request_irq(&dev->dev, irq, txx9spi_interrupt, 0,
- "spi_txx9", c);
- if (ret)
- goto exit;
-
- c->last_chipselect = NULL;
-
- dev_info(&dev->dev, "at %#llx, irq %d, %dMHz\n",
- (unsigned long long)res->start, irq,
- (c->baseclk + 500000) / 1000000);
-
- gpiod_add_lookup_table(&txx9spi_cs_gpio_table);
-
- /* the spi->mode bits understood by this driver: */
- master->mode_bits = SPI_CS_HIGH | SPI_CPOL | SPI_CPHA;
-
- master->bus_num = dev->id;
- master->setup = txx9spi_setup;
- master->transfer = txx9spi_transfer;
- master->num_chipselect = (u16)UINT_MAX; /* any GPIO numbers */
- master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
- master->use_gpio_descriptors = true;
-
- ret = devm_spi_register_master(&dev->dev, master);
- if (ret)
- goto exit;
- return 0;
-exit_busy:
- ret = -EBUSY;
-exit:
- clk_disable_unprepare(c->clk);
- spi_master_put(master);
- return ret;
-}
-
-static int txx9spi_remove(struct platform_device *dev)
-{
- struct spi_master *master = platform_get_drvdata(dev);
- struct txx9spi *c = spi_master_get_devdata(master);
-
- flush_work(&c->work);
- clk_disable_unprepare(c->clk);
- return 0;
-}
-
-/* work with hotplug and coldplug */
-MODULE_ALIAS("platform:spi_txx9");
-
-static struct platform_driver txx9spi_driver = {
- .probe = txx9spi_probe,
- .remove = txx9spi_remove,
- .driver = {
- .name = "spi_txx9",
- },
-};
-
-static int __init txx9spi_init(void)
-{
- return platform_driver_register(&txx9spi_driver);
-}
-subsys_initcall(txx9spi_init);
-
-static void __exit txx9spi_exit(void)
-{
- platform_driver_unregister(&txx9spi_driver);
-}
-module_exit(txx9spi_exit);
-
-MODULE_DESCRIPTION("TXx9 SPI Driver");
-MODULE_LICENSE("GPL");
projects / platform / kernel / linux-rpi.git / commitdiff