On Friday 22 June 2007, David Brownell wrote:
> On Friday 22 June 2007, Atsushi Nemoto wrote:
> > This is a driver for SPI controller built into TXx9 MIPS SoCs.
>
> Looks mostly pretty good. I made a few minor changes/cleanups
> in the appended version, notably:
> - checking for spi->mode bits this code doesn't understand;
> - updating to match latest patches;
>
> Note that if gpio_set_value() needs an mmiowb(), that seems like
> a bug in this platform's GPIO code; other platforms don't require
> I/O barriers after GPIO calls. Comments?
>
> Also:
>
... yeah, -ENOPATCH, sorry. And the minor whitespace fixes.
One more comment: surely platform_driver_probe() would be
appropriate here?
======= CUT HERE
From: Atsushi Nemoto <anemo@xxxxxxxxxxxxx>
This is a driver for SPI controller built into TXx9 MIPS SoCs.
This driver is derived from arch/mips/tx4938/toshiba_rbtx4938/spi_txx9.c.
Signed-off-by: Atsushi Nemoto <anemo@xxxxxxxxxxxxx>
---
drivers/spi/Kconfig | 6
drivers/spi/Makefile | 1
drivers/spi/spi_txx9.c | 434 +++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 441 insertions(+)
--- g26.orig/drivers/spi/Kconfig 2007-06-20 20:15:51.000000000 -0700
+++ g26/drivers/spi/Kconfig 2007-06-22 09:01:03.000000000 -0700
@@ -175,6 +175,12 @@ config SPI_S3C24XX_GPIO
the inbuilt hardware cannot provide the transfer mode, or
where the board is using non hardware connected pins.
+config SPI_TXX9
+ tristate "Toshiba TXx9 SPI controller"
+ depends on SPI_MASTER && GENERIC_GPIO && CPU_TX49XX
+ help
+ SPI driver for Toshiba TXx9 MIPS SoCs
+
config SPI_XILINX
tristate "Xilinx SPI controller"
depends on SPI_MASTER && XILINX_VIRTEX && EXPERIMENTAL
--- g26.orig/drivers/spi/Makefile 2007-06-20 20:15:50.000000000 -0700
+++ g26/drivers/spi/Makefile 2007-06-22 09:00:34.000000000 -0700
@@ -24,6 +24,7 @@ obj-$(CONFIG_SPI_MPC52xx_PSC) += mpc52x
obj-$(CONFIG_SPI_MPC83xx) += spi_mpc83xx.o
obj-$(CONFIG_SPI_S3C24XX_GPIO) += spi_s3c24xx_gpio.o
obj-$(CONFIG_SPI_S3C24XX) += spi_s3c24xx.o
+obj-$(CONFIG_SPI_TXX9) += spi_txx9.o
obj-$(CONFIG_SPI_XILINX) += xilinx_spi.o
# ... add above this line ...
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ g26/drivers/spi/spi_txx9.c 2007-06-22 11:48:28.000000000 -0700
@@ -0,0 +1,434 @@
+/*
+ * spi_tx99.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@xxxxxxxxxx)
+ *
+ * Convert to generic SPI framework - Atsushi Nemoto (anemo@xxxxxxxxxxxxx)
+ */
+#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 <asm/gpio.h>
+
+
+#define SPI_FIFO_SIZE 4
+
+#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 mapped;
+ int irq;
+ int baseclk;
+};
+
+struct txx9spi_cs {
+ u32 cr1;
+};
+
+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, int on)
+{
+ if (spi->mode & SPI_CS_HIGH)
+ on = !on;
+ gpio_set_value(spi->chip_select, !on);
+ mmiowb();
+}
+
+/* the spi->mode bits understood by this driver: */
+#define MODEBITS (SPI_CS_HIGH|SPI_CPOL|SPI_CPHA)
+
+static int txx9spi_setup(struct spi_device *spi)
+{
+ struct txx9spi *c = spi_master_get_devdata(spi->master);
+ struct txx9spi_cs *cs = spi->controller_state;
+ unsigned int n;
+
+ if (spi->mode & ~MODEBITS)
+ return -EINVAL;
+
+ if (!spi->max_speed_hz)
+ 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;
+ }
+
+ if (!cs) {
+ cs = kmalloc(sizeof(*cs), GFP_KERNEL);
+ if (!cs)
+ return -ENOMEM;
+ spi->controller_state = cs;
+ }
+
+ if (spi->bits_per_word == 0)
+ spi->bits_per_word = 8;
+ else if (spi->bits_per_word != 8 && spi->bits_per_word != 16)
+ return -EINVAL;
+
+ /* calc real speed */
+ n = (c->baseclk + spi->max_speed_hz - 1) / spi->max_speed_hz;
+ if (n < 1)
+ n = 1;
+ else if (n > 0xff)
+ return -EINVAL;
+ spi->max_speed_hz = c->baseclk / n;
+
+ cs->cr1 = (n << 8) | spi->bits_per_word;
+ 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 int txx9spi_work_one(struct txx9spi *c, struct spi_message *m)
+{
+ struct spi_device *spi = m->spi;
+ struct txx9spi_cs *cs = spi->controller_state;
+ struct spi_transfer *t;
+ unsigned int nsecs;
+ unsigned int cs_change;
+ int status;
+ u32 mcr;
+
+ mcr = txx9spi_rd(c, TXx9_SPMCR);
+ if (unlikely((mcr & TXx9_SPMCR_OPMODE) == TXx9_SPMCR_ACTIVE)) {
+ dev_err(&spi->dev, "Bad mode.\n");
+ return -EIO;
+ }
+
+ /* enter config mode */
+ mcr &= ~(TXx9_SPMCR_OPMODE | TXx9_SPMCR_SPSTP | TXx9_SPMCR_BCLR);
+ 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);
+ txx9spi_wr(c, cs->cr1, TXx9_SPCR1);
+ /* enter active mode */
+ txx9spi_wr(c, mcr | TXx9_SPMCR_ACTIVE, TXx9_SPMCR);
+
+ cs_change = 1;
+ status = 0;
+ nsecs = 100 + 1000000000 / spi->max_speed_hz / 2;
+ 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 = spi->bits_per_word >> 3; /* in bytes */
+ if ((!txbuf && !rxbuf && len) || (len & (wsize - 1))) {
+ status = -EINVAL;
+ break;
+ }
+ if (cs_change) {
+ txx9spi_cs_func(spi, 1);
+ ndelay(nsecs);
+ }
+ 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))
+ ;
+ 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++) {
+ data = txbuf ? (wsize == 1 ?
+ *(const u8 *)txbuf :
+ *(const u16 *)txbuf) : 0;
+ txx9spi_wr(c, data, TXx9_SPDR);
+ if (txbuf)
+ txbuf += wsize;
+ }
+ /* 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
+ */
+ ndelay(nsecs);
+ txx9spi_cs_func(spi, 0);
+ ndelay(nsecs);
+ }
+
+ 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)) {
+ ndelay(nsecs);
+ txx9spi_cs_func(spi, 0);
+ ndelay(nsecs);
+ }
+
+ /* enter config mode */
+ txx9spi_wr(c, mcr | TXx9_SPMCR_CONFIG | TXx9_SPMCR_BCLR, TXx9_SPMCR);
+ return status;
+}
+
+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);
+ unsigned long flags;
+
+ m->actual_length = 0;
+ 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 void txx9spi_cleanup(struct spi_device *spi)
+{
+ kfree(spi->controller_state);
+}
+
+#ifdef CONFIG_64BIT
+#define TXX9_DIRECTMAP_BASE 0xfff000000ul
+#else
+#define TXX9_DIRECTMAP_BASE 0xff000000ul
+#endif
+
+static int __init txx9spi_probe(struct platform_device *dev)
+{
+ struct spi_master *master;
+ struct txx9spi *c;
+ struct resource *res;
+ int ret = -ENODEV;
+ u32 mcr;
+
+ 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);
+
+ res = platform_get_resource(dev, IORESOURCE_MEM, 0);
+ if (!res)
+ goto put_and_exit;
+ if (res->start >= TXX9_DIRECTMAP_BASE)
+ c->membase = (void __iomem *)(unsigned long)(int)res->start;
+ else {
+ c->membase = ioremap(res->start, res->end - res->start + 1);
+ c->mapped = 1;
+ }
+
+ /* 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);
+
+ c->irq = platform_get_irq(dev, 0);
+ if (c->irq < 0)
+ goto res_and_exit;
+ c->baseclk = platform_get_irq_byname(dev, "baseclk");
+ if (c->baseclk < 0)
+ goto res_and_exit;
+ ret = request_irq(c->irq, txx9spi_interrupt, 0, dev->name, c);
+ if (ret)
+ goto res_and_exit;
+
+ c->workqueue = create_singlethread_workqueue(master->cdev.dev->bus_id);
+ if (!c->workqueue)
+ goto irq_and_exit;
+
+ dev_info(&dev->dev, "at 0x%llx, irq %d, %dMHz\n",
+ (unsigned long long)res->start, c->irq,
+ (c->baseclk + 500000) / 1000000);
+
+ master->bus_num = dev->id;
+ master->setup = txx9spi_setup;
+ master->transfer = txx9spi_transfer;
+ master->cleanup = txx9spi_cleanup;
+
+ ret = spi_register_master(master);
+ if (ret)
+ goto wq_and_exit;
+ return 0;
+ wq_and_exit:
+ destroy_workqueue(c->workqueue);
+ irq_and_exit:
+ free_irq(c->irq, c);
+ res_and_exit:
+ if (c->mapped)
+ iounmap(c->membase);
+ put_and_exit:
+ 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);
+ free_irq(c->irq, c);
+ if (c->mapped)
+ iounmap(c->membase);
+ spi_master_put(master);
+ return 0;
+}
+
+static struct platform_driver txx9spi_driver = {
+ .probe = txx9spi_probe,
+ .remove = __exit_p(txx9spi_remove),
+ .driver = {
+ .name = "txx9spi",
+ .owner = THIS_MODULE,
+ },
+};
+
+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");
