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linux-next/drivers/spi/spi-sh.c
Mark Brown e2185072a4
spi: sh: Switch to using core message queue 
We deprecated open coding of the transfer queue back in 2017 so it's high
time we finished up converting drivers to use the standard message queue
code. The SH driver is fairly straightforward so convert to use
transfer_one_message(), it looks like the driver would be a good fit for
transfer_one() with a little bit of updating but this smaller change seems
safer.

I'm not actually clear how the driver worked robustly previously, it
clears SSA and CR1 when queueing a transfer which looks like it would
interfere with any running transfer. This clearing has been moved to the
start of the message transfer function.

I'm also unclear how exactly the chip select is managed with this driver.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220610154649.1707851-1-broonie@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>
2022-06-27 13:24:35 +01:00

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// SPDX-License-Identifier: GPL-2.0
/*
* SH SPI bus driver
*
* Copyright (C) 2011 Renesas Solutions Corp.
*
* Based on pxa2xx_spi.c:
* Copyright (C) 2005 Stephen Street / StreetFire Sound Labs
*/
#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;
unsigned long cr1;
wait_queue_head_t wait;
int width;
};
static void spi_sh_write(struct spi_sh_data *ss, unsigned long data,
unsigned long offset)
{
if (ss->width == 8)
iowrite8(data, ss->addr + (offset >> 2));
else if (ss->width == 32)
iowrite32(data, ss->addr + offset);
}
static unsigned long spi_sh_read(struct spi_sh_data *ss, unsigned long offset)
{
if (ss->width == 8)
return ioread8(ss->addr + (offset >> 2));
else if (ss->width == 32)
return ioread32(ss->addr + offset);
else
return 0;
}
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;
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)) {
spi_sh_clear_bit(ss, SPI_SH_SSD | SPI_SH_SSDB, 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;
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);
spi_sh_clear_bit(ss, SPI_SH_SSD | SPI_SH_SSDB, 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 int spi_sh_transfer_one_message(struct spi_controller *ctlr,
struct spi_message *mesg)
{
struct spi_sh_data *ss = spi_controller_get_devdata(ctlr);
struct spi_transfer *t;
int ret;
pr_debug("%s: enter\n", __func__);
spi_sh_clear_bit(ss, SPI_SH_SSA, SPI_SH_CR1);
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.value = %d\n",
t->len, t->delay.value);
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;
}
mesg->status = 0;
spi_finalize_current_message(ctlr);
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);
return 0;
error:
mesg->status = ret;
spi_finalize_current_message(ctlr);
if (mesg->complete)
mesg->complete(mesg->context);
spi_sh_clear_bit(ss, SPI_SH_SSA | SPI_SH_SSDB | SPI_SH_SSD,
SPI_SH_CR1);
clear_fifo(ss);
return ret;
}
static int spi_sh_setup(struct spi_device *spi)
{
struct spi_sh_data *ss = spi_master_get_devdata(spi->master);
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 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 = platform_get_drvdata(pdev);
spi_unregister_master(ss->master);
free_irq(ss->irq, ss);
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)
return irq;
master = devm_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);
platform_set_drvdata(pdev, ss);
switch (res->flags & IORESOURCE_MEM_TYPE_MASK) {
case IORESOURCE_MEM_8BIT:
ss->width = 8;
break;
case IORESOURCE_MEM_32BIT:
ss->width = 32;
break;
default:
dev_err(&pdev->dev, "No support width\n");
return -ENODEV;
}
ss->irq = irq;
ss->master = master;
ss->addr = devm_ioremap(&pdev->dev, res->start, resource_size(res));
if (ss->addr == NULL) {
dev_err(&pdev->dev, "ioremap error.\n");
return -ENOMEM;
}
init_waitqueue_head(&ss->wait);
ret = request_irq(irq, spi_sh_irq, 0, "spi_sh", ss);
if (ret < 0) {
dev_err(&pdev->dev, "request_irq error\n");
return ret;
}
master->num_chipselect = 2;
master->bus_num = pdev->id;
master->setup = spi_sh_setup;
master->transfer_one_message = spi_sh_transfer_one_message;
master->cleanup = spi_sh_cleanup;
ret = spi_register_master(master);
if (ret < 0) {
printk(KERN_ERR "spi_register_master error.\n");
goto error3;
}
return 0;
error3:
free_irq(irq, ss);
return ret;
}
static struct platform_driver spi_sh_driver = {
.probe = spi_sh_probe,
.remove = spi_sh_remove,
.driver = {
.name = "sh_spi",
},
};
module_platform_driver(spi_sh_driver);
MODULE_DESCRIPTION("SH SPI bus driver");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Yoshihiro Shimoda");
MODULE_ALIAS("platform:sh_spi");
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