[PATCH] spi: add support for SuperH SPI

Yoshihiro Shimoda
2011-02-15T01:30:32Z

The SH7757 has SPI0 module. This patch supports it.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
---
drivers/spi/Kconfig | 6 +
drivers/spi/Makefile | 1 +
drivers/spi/spi_sh.c | 547 ++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 554 insertions(+), 0 deletions(-)
create mode 100644 drivers/spi/spi_sh.c

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index bb233a9..1532d2c 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -330,6 +330,12 @@ config SPI_SH_MSIOF
help
SPI driver for SuperH MSIOF blocks.

+config SPI_SH
+ tristate "SuperH SPI controller"
+ depends on SUPERH
+ help
+ SPI driver for SuperH SPI blocks.
+
config SPI_SH_SCI
tristate "SuperH SCI SPI controller"
depends on SUPERH
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 86d1b5f..068465f 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -48,6 +48,7 @@ obj-$(CONFIG_SPI_TXX9) += spi_txx9.o
obj-$(CONFIG_SPI_XILINX) += xilinx_spi.o
obj-$(CONFIG_SPI_SH_SCI) += spi_sh_sci.o
obj-$(CONFIG_SPI_SH_MSIOF) += spi_sh_msiof.o
+obj-$(CONFIG_SPI_SH) += spi_sh.o
obj-$(CONFIG_SPI_STMP3XXX) += spi_stmp.o
obj-$(CONFIG_SPI_NUC900) += spi_nuc900.o

diff --git a/drivers/spi/spi_sh.c b/drivers/spi/spi_sh.c
new file mode 100644
index 0000000..247ef0b
--- /dev/null
+++ b/drivers/spi/spi_sh.c
@@ -0,0 +1,547 @@
+/*
+ * SH SPI bus driver
+ *
+ * Copyright (C) 2011 Renesas Solutions Corp.
+ *
+ * Based on pxa2xx_spi.c:
+ * Copyright (C) 2005 Stephen Street / StreetFire Sound Labs
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/errno.h>
+#include <linux/timer.h>
+#include <linux/delay.h>
+#include <linux/list.h>
+#include <linux/workqueue.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/spi/spi.h>
+
+#define DRIVER_VERSION "2011-02-02"
+
+#define SPI_SH_TBR 0x00
+#define SPI_SH_RBR 0x00
+#define SPI_SH_CR1 0x08
+#define SPI_SH_CR2 0x10
+#define SPI_SH_CR3 0x18
+#define SPI_SH_CR4 0x20
+#define SPI_SH_CR5 0x28
+
+/* CR1 */
+#define SPI_SH_TBE 0x80
+#define SPI_SH_TBF 0x40
+#define SPI_SH_RBE 0x20
+#define SPI_SH_RBF 0x10
+#define SPI_SH_PFONRD 0x08
+#define SPI_SH_SSDB 0x04
+#define SPI_SH_SSD 0x02
+#define SPI_SH_SSA 0x01
+
+/* CR2 */
+#define SPI_SH_RSTF 0x80
+#define SPI_SH_LOOPBK 0x40
+#define SPI_SH_CPOL 0x20
+#define SPI_SH_CPHA 0x10
+#define SPI_SH_L1M0 0x08
+
+/* CR3 */
+#define SPI_SH_MAX_BYTE 0xFF
+
+/* CR4 */
+#define SPI_SH_TBEI 0x80
+#define SPI_SH_TBFI 0x40
+#define SPI_SH_RBEI 0x20
+#define SPI_SH_RBFI 0x10
+#define SPI_SH_WPABRT 0x04
+#define SPI_SH_SSS 0x01
+
+/* CR8 */
+#define SPI_SH_P1L0 0x80
+#define SPI_SH_PP1L0 0x40
+#define SPI_SH_MUXI 0x20
+#define SPI_SH_MUXIRQ 0x10
+
+#define SPI_SH_FIFO_SIZE 32
+#define SPI_SH_SEND_TIMEOUT (3 * HZ)
+#define SPI_SH_RECEIVE_TIMEOUT (HZ >> 3)
+
+#undef DEBUG
+
+struct spi_sh_data {
+ void __iomem *addr;
+ int irq;
+ struct spi_master *master;
+ struct list_head queue;
+ struct workqueue_struct *workqueue;
+ struct work_struct ws;
+ unsigned long cr1;
+ wait_queue_head_t wait;
+ spinlock_t lock;
+};
+
+static void spi_sh_write(struct spi_sh_data *ss, unsigned long data,
+ unsigned long offset)
+{
+ writel(data, ss->addr + offset);
+}
+
+static unsigned long spi_sh_read(struct spi_sh_data *ss, unsigned long offset)
+{
+ return readl(ss->addr + offset);
+}
+
+static void spi_sh_set_bit(struct spi_sh_data *ss, unsigned long val,
+ unsigned long offset)
+{
+ unsigned long tmp;
+
+ tmp = spi_sh_read(ss, offset);
+ tmp |= val;
+ spi_sh_write(ss, tmp, offset);
+}
+
+static void spi_sh_clear_bit(struct spi_sh_data *ss, unsigned long val,
+ unsigned long offset)
+{
+ unsigned long tmp;
+
+ tmp = spi_sh_read(ss, offset);
+ tmp &= ~val;
+ spi_sh_write(ss, tmp, offset);
+}
+
+static void clear_fifo(struct spi_sh_data *ss)
+{
+ spi_sh_set_bit(ss, SPI_SH_RSTF, SPI_SH_CR2);
+ spi_sh_clear_bit(ss, SPI_SH_RSTF, SPI_SH_CR2);
+}
+
+static int wait_receive_buffer(struct spi_sh_data *ss)
+{
+ int timeout = 100000;
+
+ while (spi_sh_read(ss, SPI_SH_CR1) & SPI_SH_RBE) {
+ udelay(10);
+ if (timeout-- < 0)
+ return -ETIMEDOUT;
+ }
+ return 0;
+}
+
+static int wait_write_buffer_empty(struct spi_sh_data *ss)
+{
+ int timeout = 100000;
+
+ while (!(spi_sh_read(ss, SPI_SH_CR1) & SPI_SH_TBE)) {
+ udelay(10);
+ if (timeout-- < 0)
+ return -ETIMEDOUT;
+ }
+ return 0;
+}
+
+static int spi_sh_send(struct spi_sh_data *ss, struct spi_message *mesg,
+ struct spi_transfer *t)
+{
+ int i, retval = 0;
+ int remain = t->len;
+ int cur_len;
+ unsigned char *data;
+ unsigned long tmp;
+ long ret;
+
+ if (t->len)
+ spi_sh_set_bit(ss, SPI_SH_SSA, SPI_SH_CR1);
+
+ data = (unsigned char *)t->tx_buf;
+ while (remain > 0) {
+ cur_len = min(SPI_SH_FIFO_SIZE, remain);
+ for (i = 0; i < cur_len &&
+ !(spi_sh_read(ss, SPI_SH_CR4) &
+ SPI_SH_WPABRT) &&
+ !(spi_sh_read(ss, SPI_SH_CR1) & SPI_SH_TBF);
+ i++)
+ spi_sh_write(ss, (unsigned long)data[i], SPI_SH_TBR);
+
+ if (spi_sh_read(ss, SPI_SH_CR4) & SPI_SH_WPABRT) {
+ /* Abort SPI operation */
+ spi_sh_set_bit(ss, SPI_SH_WPABRT, SPI_SH_CR4);
+ retval = -EIO;
+ break;
+ }
+
+ cur_len = i;
+
+ remain -= cur_len;
+ data += cur_len;
+
+ if (remain > 0) {
+ ss->cr1 &= ~SPI_SH_TBE;
+ spi_sh_set_bit(ss, SPI_SH_TBE, SPI_SH_CR4);
+ ret = wait_event_interruptible_timeout(ss->wait,
+ ss->cr1 & SPI_SH_TBE,
+ SPI_SH_SEND_TIMEOUT);
+ if (ret = 0 && !(ss->cr1 & SPI_SH_TBE)) {
+ printk(KERN_ERR "%s: timeout\n", __func__);
+ return -ETIMEDOUT;
+ }
+ }
+ }
+
+ if (list_is_last(&t->transfer_list, &mesg->transfers)) {
+ tmp = spi_sh_read(ss, SPI_SH_CR1);
+ tmp = tmp & ~(SPI_SH_SSD | SPI_SH_SSDB);
+ spi_sh_write(ss, tmp, SPI_SH_CR1);
+ spi_sh_set_bit(ss, SPI_SH_SSA, SPI_SH_CR1);
+
+ ss->cr1 &= ~SPI_SH_TBE;
+ spi_sh_set_bit(ss, SPI_SH_TBE, SPI_SH_CR4);
+ ret = wait_event_interruptible_timeout(ss->wait,
+ ss->cr1 & SPI_SH_TBE,
+ SPI_SH_SEND_TIMEOUT);
+ if (ret = 0 && (ss->cr1 & SPI_SH_TBE)) {
+ printk(KERN_ERR "%s: timeout\n", __func__);
+ return -ETIMEDOUT;
+ }
+ }
+
+ return retval;
+}
+
+static int spi_sh_receive(struct spi_sh_data *ss, struct spi_message *mesg,
+ struct spi_transfer *t)
+{
+ int i;
+ int remain = t->len;
+ int cur_len;
+ unsigned char *data;
+ unsigned long tmp;
+ long ret;
+
+ if (t->len > SPI_SH_MAX_BYTE)
+ spi_sh_write(ss, SPI_SH_MAX_BYTE, SPI_SH_CR3);
+ else
+ spi_sh_write(ss, t->len, SPI_SH_CR3);
+
+ tmp = spi_sh_read(ss, SPI_SH_CR1);
+ tmp = tmp & ~(SPI_SH_SSD | SPI_SH_SSDB);
+ spi_sh_write(ss, tmp, SPI_SH_CR1);
+ spi_sh_set_bit(ss, SPI_SH_SSA, SPI_SH_CR1);
+
+ wait_write_buffer_empty(ss);
+
+ data = (unsigned char *)t->rx_buf;
+ while (remain > 0) {
+ if (remain >= SPI_SH_FIFO_SIZE) {
+ ss->cr1 &= ~SPI_SH_RBF;
+ spi_sh_set_bit(ss, SPI_SH_RBF, SPI_SH_CR4);
+ ret = wait_event_interruptible_timeout(ss->wait,
+ ss->cr1 & SPI_SH_RBF,
+ SPI_SH_RECEIVE_TIMEOUT);
+ if (ret = 0 &&
+ spi_sh_read(ss, SPI_SH_CR1) & SPI_SH_RBE) {
+ printk(KERN_ERR "%s: timeout\n", __func__);
+ return -ETIMEDOUT;
+ }
+ }
+
+ cur_len = min(SPI_SH_FIFO_SIZE, remain);
+ for (i = 0; i < cur_len; i++) {
+ if (wait_receive_buffer(ss))
+ break;
+ data[i] = (unsigned char)spi_sh_read(ss, SPI_SH_RBR);
+ }
+
+ remain -= cur_len;
+ data += cur_len;
+ }
+
+ /* deassert CS when SPI is receiving. */
+ if (t->len > SPI_SH_MAX_BYTE) {
+ clear_fifo(ss);
+ spi_sh_write(ss, 1, SPI_SH_CR3);
+ } else {
+ spi_sh_write(ss, 0, SPI_SH_CR3);
+ }
+
+ return 0;
+}
+
+static void spi_sh_work(struct work_struct *work)
+{
+ struct spi_sh_data *ss = container_of(work, struct spi_sh_data, ws);
+ struct spi_message *mesg;
+ struct spi_transfer *t;
+ unsigned long flags;
+ int ret;
+
+ pr_debug("%s: enter\n", __func__);
+
+ spin_lock_irqsave(&ss->lock, flags);
+ while (!list_empty(&ss->queue)) {
+ mesg = list_entry(ss->queue.next, struct spi_message, queue);
+ list_del_init(&mesg->queue);
+
+ spin_unlock_irqrestore(&ss->lock, flags);
+ list_for_each_entry(t, &mesg->transfers, transfer_list) {
+ pr_debug("tx_buf = %p, rx_buf = %p\n",
+ t->tx_buf, t->rx_buf);
+ pr_debug("len = %d, delay_usecs = %d\n",
+ t->len, t->delay_usecs);
+
+ if (t->tx_buf) {
+ ret = spi_sh_send(ss, mesg, t);
+ if (ret < 0)
+ goto error;
+ }
+ if (t->rx_buf) {
+ ret = spi_sh_receive(ss, mesg, t);
+ if (ret < 0)
+ goto error;
+ }
+ mesg->actual_length += t->len;
+ }
+ spin_lock_irqsave(&ss->lock, flags);
+
+ mesg->status = 0;
+ mesg->complete(mesg->context);
+ }
+
+ clear_fifo(ss);
+ spi_sh_set_bit(ss, SPI_SH_SSD, SPI_SH_CR1);
+ udelay(100);
+
+ spi_sh_clear_bit(ss, SPI_SH_SSA | SPI_SH_SSDB | SPI_SH_SSD,
+ SPI_SH_CR1);
+
+ clear_fifo(ss);
+
+ spin_unlock_irqrestore(&ss->lock, flags);
+
+ return;
+
+error:
+ mesg->status = ret;
+ mesg->complete(mesg->context);
+
+ spi_sh_clear_bit(ss, SPI_SH_SSA | SPI_SH_SSDB | SPI_SH_SSD,
+ SPI_SH_CR1);
+ clear_fifo(ss);
+
+}
+
+static int spi_sh_setup(struct spi_device *spi)
+{
+ struct spi_sh_data *ss = spi_master_get_devdata(spi->master);
+
+ if (!spi->bits_per_word)
+ spi->bits_per_word = 8;
+
+ pr_debug("%s: enter\n", __func__);
+
+ spi_sh_write(ss, 0xfe, SPI_SH_CR1); /* SPI sycle stop */
+ spi_sh_write(ss, 0x00, SPI_SH_CR1); /* CR1 init */
+ spi_sh_write(ss, 0x00, SPI_SH_CR3); /* CR3 init */
+
+ clear_fifo(ss);
+
+ /* 1/8 clock */
+ spi_sh_write(ss, spi_sh_read(ss, SPI_SH_CR2) | 0x07, SPI_SH_CR2);
+ udelay(10);
+
+ return 0;
+}
+
+static int spi_sh_transfer(struct spi_device *spi, struct spi_message *mesg)
+{
+ struct spi_sh_data *ss = spi_master_get_devdata(spi->master);
+ unsigned long flags;
+
+ pr_debug("%s: enter\n", __func__);
+ pr_debug("\tmode = %02x\n", spi->mode);
+
+ spin_lock_irqsave(&ss->lock, flags);
+
+ mesg->actual_length = 0;
+ mesg->status = -EINPROGRESS;
+
+ spi_sh_clear_bit(ss, SPI_SH_SSA, SPI_SH_CR1);
+
+ list_add_tail(&mesg->queue, &ss->queue);
+ queue_work(ss->workqueue, &ss->ws);
+
+ spin_unlock_irqrestore(&ss->lock, flags);
+
+ return 0;
+}
+
+static void spi_sh_cleanup(struct spi_device *spi)
+{
+ struct spi_sh_data *ss = spi_master_get_devdata(spi->master);
+
+ pr_debug("%s: enter\n", __func__);
+
+ spi_sh_clear_bit(ss, SPI_SH_SSA | SPI_SH_SSDB | SPI_SH_SSD,
+ SPI_SH_CR1);
+}
+
+static irqreturn_t spi_sh_irq(int irq, void *_ss)
+{
+ struct spi_sh_data *ss = (struct spi_sh_data *)_ss;
+ unsigned long cr1;
+
+ cr1 = spi_sh_read(ss, SPI_SH_CR1);
+ if (cr1 & SPI_SH_TBE)
+ ss->cr1 |= SPI_SH_TBE;
+ if (cr1 & SPI_SH_TBF)
+ ss->cr1 |= SPI_SH_TBF;
+ if (cr1 & SPI_SH_RBE)
+ ss->cr1 |= SPI_SH_RBE;
+ if (cr1 & SPI_SH_RBF)
+ ss->cr1 |= SPI_SH_RBF;
+
+ if (ss->cr1) {
+ spi_sh_clear_bit(ss, ss->cr1, SPI_SH_CR4);
+ wake_up(&ss->wait);
+ }
+
+ return IRQ_HANDLED;
+}
+
+static int spi_sh_remove(struct platform_device *pdev)
+{
+ struct spi_sh_data *ss = dev_get_drvdata(&pdev->dev);
+
+ destroy_workqueue(ss->workqueue);
+ free_irq(ss->irq, ss);
+ iounmap(ss->addr);
+ spi_master_put(ss->master);
+
+ return 0;
+}
+
+static int spi_sh_probe(struct platform_device *pdev)
+{
+ struct resource *res;
+ struct spi_master *master;
+ struct spi_sh_data *ss;
+ int ret, irq;
+
+ /* get base addr */
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (unlikely(res = NULL)) {
+ dev_err(&pdev->dev, "invalid resource\n");
+ return -EINVAL;
+ }
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0) {
+ dev_err(&pdev->dev, "platform_get_irq error\n");
+ return -ENODEV;
+ }
+
+ master = spi_alloc_master(&pdev->dev, sizeof(struct spi_sh_data));
+ if (master = NULL) {
+ dev_err(&pdev->dev, "spi_alloc_master error.\n");
+ return -ENOMEM;
+ }
+
+ ss = spi_master_get_devdata(master);
+ dev_set_drvdata(&pdev->dev, ss);
+
+ ss->irq = irq;
+ ss->master = master;
+ ss->addr = ioremap(res->start, resource_size(res));
+ if (ss->addr = NULL) {
+ dev_err(&pdev->dev, "ioremap error.\n");
+ ret = -ENOMEM;
+ goto error1;
+ }
+ INIT_LIST_HEAD(&ss->queue);
+ spin_lock_init(&ss->lock);
+ INIT_WORK(&ss->ws, spi_sh_work);
+ init_waitqueue_head(&ss->wait);
+ ss->workqueue = create_singlethread_workqueue(
+ dev_name(master->dev.parent));
+ if (ss->workqueue = NULL) {
+ dev_err(&pdev->dev, "create workqueue error\n");
+ ret = -EBUSY;
+ goto error2;
+ }
+
+ ret = request_irq(irq, spi_sh_irq, IRQF_DISABLED, "spi_sh", ss);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "request_irq error\n");
+ goto error3;
+ }
+
+ master->num_chipselect = 2;
+ master->bus_num = pdev->id;
+ master->setup = spi_sh_setup;
+ master->transfer = spi_sh_transfer;
+ master->cleanup = spi_sh_cleanup;
+
+ ret = spi_register_master(master);
+ if (ret < 0) {
+ printk(KERN_ERR "spi_register_master error.\n");
+ goto error4;
+ }
+
+ printk(KERN_INFO "spi_sh: version %s\n", DRIVER_VERSION);
+
+ return 0;
+
+error4:
+ free_irq(irq, ss);
+error3:
+ destroy_workqueue(ss->workqueue);
+error2:
+ iounmap(ss->addr);
+error1:
+ spi_master_put(master);
+
+ return ret;
+}
+
+static struct platform_driver spi_sh_driver = {
+ .probe = spi_sh_probe,
+ .remove = spi_sh_remove,
+ .driver = {
+ .name = "sh_spi",
+ .owner = THIS_MODULE,
+ },
+};
+
+static int __init spi_sh_init(void)
+{
+ return platform_driver_register(&spi_sh_driver);
+}
+
+static void __exit spi_sh_exit(void)
+{
+ platform_driver_unregister(&spi_sh_driver);
+}
+module_init(spi_sh_init);
+module_exit(spi_sh_exit);
+
+MODULE_DESCRIPTION("SH SPI bus driver");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Yoshihiro Shimoda");
+MODULE_ALIAS("platform:sh_spi");
--
1.7.1