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path: root/drivers/spi/spi_txx9.c
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Diffstat (limited to 'drivers/spi/spi_txx9.c')
-rw-r--r--drivers/spi/spi_txx9.c472
1 files changed, 472 insertions, 0 deletions
diff --git a/drivers/spi/spi_txx9.c b/drivers/spi/spi_txx9.c
new file mode 100644
index 00000000..dfa024b6
--- /dev/null
+++ b/drivers/spi/spi_txx9.c
@@ -0,0 +1,472 @@
+/*
+ * spi_txx9.c - 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 <asm/gpio.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 workqueue_struct *workqueue;
+ 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;
+ u32 max_speed_hz, min_speed_hz;
+ int 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)
+{
+ int val = (spi->mode & SPI_CS_HIGH) ? on : !on;
+ if (on) {
+ /* deselect the chip with cs_change hint in last transfer */
+ if (c->last_chipselect >= 0)
+ gpio_set_value(c->last_chipselect,
+ !c->last_chipselect_val);
+ c->last_chipselect = spi->chip_select;
+ c->last_chipselect_val = val;
+ } else {
+ c->last_chipselect = -1;
+ ndelay(cs_delay); /* CS Hold Time */
+ }
+ gpio_set_value(spi->chip_select, val);
+ 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);
+ u8 bits_per_word;
+
+ if (!spi->max_speed_hz
+ || spi->max_speed_hz > c->max_speed_hz
+ || spi->max_speed_hz < c->min_speed_hz)
+ return -EINVAL;
+
+ bits_per_word = spi->bits_per_word;
+ if (bits_per_word != 8 && bits_per_word != 16)
+ return -EINVAL;
+
+ if (gpio_direction_output(spi->chip_select,
+ !(spi->mode & SPI_CS_HIGH))) {
+ dev_err(&spi->dev, "Cannot setup GPIO for chipselect.\n");
+ 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 ? : spi->max_speed_hz;
+ u8 bits_per_word = t->bits_per_word ? : spi->bits_per_word;
+
+ bits_per_word = bits_per_word ? : 8;
+ 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;
+ if (t->delay_usecs)
+ udelay(t->delay_usecs);
+
+ 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;
+ 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) {
+ u32 speed_hz = t->speed_hz ? : spi->max_speed_hz;
+ u8 bits_per_word = t->bits_per_word ? : spi->bits_per_word;
+
+ bits_per_word = bits_per_word ? : 8;
+ if (!t->tx_buf && !t->rx_buf && t->len)
+ return -EINVAL;
+ if (bits_per_word != 8 && bits_per_word != 16)
+ return -EINVAL;
+ if (t->len & ((bits_per_word >> 3) - 1))
+ return -EINVAL;
+ if (speed_hz < c->min_speed_hz || speed_hz > c->max_speed_hz)
+ return -EINVAL;
+ }
+
+ spin_lock_irqsave(&c->lock, flags);
+ list_add_tail(&m->queue, &c->queue);
+ queue_work(c->workqueue, &c->work);
+ spin_unlock_irqrestore(&c->lock, flags);
+
+ return 0;
+}
+
+static int __init 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 = clk_get(&dev->dev, "spi-baseclk");
+ if (IS_ERR(c->clk)) {
+ ret = PTR_ERR(c->clk);
+ c->clk = NULL;
+ goto exit;
+ }
+ ret = clk_enable(c->clk);
+ if (ret) {
+ clk_put(c->clk);
+ c->clk = NULL;
+ goto exit;
+ }
+ c->baseclk = clk_get_rate(c->clk);
+ c->min_speed_hz = DIV_ROUND_UP(c->baseclk, SPI_MAX_DIVIDER + 1);
+ c->max_speed_hz = c->baseclk / (SPI_MIN_DIVIDER + 1);
+
+ res = platform_get_resource(dev, IORESOURCE_MEM, 0);
+ if (!res)
+ goto exit_busy;
+ if (!devm_request_mem_region(&dev->dev, res->start, resource_size(res),
+ "spi_txx9"))
+ goto exit_busy;
+ c->membase = devm_ioremap(&dev->dev, res->start, resource_size(res));
+ if (!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->workqueue = create_singlethread_workqueue(
+ dev_name(master->dev.parent));
+ if (!c->workqueue)
+ goto exit_busy;
+ c->last_chipselect = -1;
+
+ dev_info(&dev->dev, "at %#llx, irq %d, %dMHz\n",
+ (unsigned long long)res->start, irq,
+ (c->baseclk + 500000) / 1000000);
+
+ /* 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 */
+
+ ret = spi_register_master(master);
+ if (ret)
+ goto exit;
+ return 0;
+exit_busy:
+ ret = -EBUSY;
+exit:
+ if (c->workqueue)
+ destroy_workqueue(c->workqueue);
+ if (c->clk) {
+ clk_disable(c->clk);
+ clk_put(c->clk);
+ }
+ platform_set_drvdata(dev, NULL);
+ spi_master_put(master);
+ return ret;
+}
+
+static int __exit txx9spi_remove(struct platform_device *dev)
+{
+ struct spi_master *master = spi_master_get(platform_get_drvdata(dev));
+ struct txx9spi *c = spi_master_get_devdata(master);
+
+ spi_unregister_master(master);
+ platform_set_drvdata(dev, NULL);
+ destroy_workqueue(c->workqueue);
+ clk_disable(c->clk);
+ clk_put(c->clk);
+ spi_master_put(master);
+ return 0;
+}
+
+/* work with hotplug and coldplug */
+MODULE_ALIAS("platform:spi_txx9");
+
+static struct platform_driver txx9spi_driver = {
+ .remove = __exit_p(txx9spi_remove),
+ .driver = {
+ .name = "spi_txx9",
+ .owner = THIS_MODULE,
+ },
+};
+
+static int __init txx9spi_init(void)
+{
+ return platform_driver_probe(&txx9spi_driver, txx9spi_probe);
+}
+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");
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-22 05:22:38 +0000