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/*
* 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 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 spi_sh_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 spi_sh_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);
spi_sh_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 (spi_sh_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 __devexit spi_sh_remove(struct platform_device *pdev)
{
struct spi_sh_data *ss = dev_get_drvdata(&pdev->dev);
spi_unregister_master(ss->master);
destroy_workqueue(ss->workqueue);
free_irq(ss->irq, ss);
iounmap(ss->addr);
return 0;
}
static int __devinit 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;
}
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 = __devexit_p(spi_sh_remove),
.driver = {
.name = "sh_spi",
.owner = THIS_MODULE,
},
};
static int __init spi_sh_init(void)
{
return platform_driver_register(&spi_sh_driver);
}
module_init(spi_sh_init);
static void __exit spi_sh_exit(void)
{
platform_driver_unregister(&spi_sh_driver);
}
module_exit(spi_sh_exit);
MODULE_DESCRIPTION("SH SPI bus driver");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Yoshihiro Shimoda");
MODULE_ALIAS("platform:sh_spi");