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linux/drivers/spi/spi-coldfire-qspi.c
Laxman Dewangan 766ed70447 spi: remove check for bits_per_word on transfer from low level driver 
The spi core make sure that each transfer structure have the proper
setting for bits_per_word before calling low level transfer APIs.

Hence it is no more require to check again in low level driver for
this field whether this is set correct or not. Removing such code
from low level driver.

The txx9 change also removes a test for bits_per_word set to 0, and
forcing it to 8 in that case. This can also be removed now since
spi_setup() ensures spi->bits_per_word is not zero.

	if (!spi->bits_per_word)
		spi->bits_per_word = 8;

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2013-02-05 12:26:59 +00:00

604 lines
15 KiB
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/*
* Freescale/Motorola Coldfire Queued SPI driver
*
* Copyright 2010 Steven King <sfking@fdwdc.com>
*
* 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; either version 2 of the License, or
* (at your option) any later version.
*
* 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/kernel.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/errno.h>
#include <linux/platform_device.h>
#include <linux/sched.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/spi/spi.h>
#include <linux/pm_runtime.h>
#include <asm/coldfire.h>
#include <asm/mcfsim.h>
#include <asm/mcfqspi.h>
#define DRIVER_NAME "mcfqspi"
#define MCFQSPI_BUSCLK (MCF_BUSCLK / 2)
#define MCFQSPI_QMR 0x00
#define MCFQSPI_QMR_MSTR 0x8000
#define MCFQSPI_QMR_CPOL 0x0200
#define MCFQSPI_QMR_CPHA 0x0100
#define MCFQSPI_QDLYR 0x04
#define MCFQSPI_QDLYR_SPE 0x8000
#define MCFQSPI_QWR 0x08
#define MCFQSPI_QWR_HALT 0x8000
#define MCFQSPI_QWR_WREN 0x4000
#define MCFQSPI_QWR_CSIV 0x1000
#define MCFQSPI_QIR 0x0C
#define MCFQSPI_QIR_WCEFB 0x8000
#define MCFQSPI_QIR_ABRTB 0x4000
#define MCFQSPI_QIR_ABRTL 0x1000
#define MCFQSPI_QIR_WCEFE 0x0800
#define MCFQSPI_QIR_ABRTE 0x0400
#define MCFQSPI_QIR_SPIFE 0x0100
#define MCFQSPI_QIR_WCEF 0x0008
#define MCFQSPI_QIR_ABRT 0x0004
#define MCFQSPI_QIR_SPIF 0x0001
#define MCFQSPI_QAR 0x010
#define MCFQSPI_QAR_TXBUF 0x00
#define MCFQSPI_QAR_RXBUF 0x10
#define MCFQSPI_QAR_CMDBUF 0x20
#define MCFQSPI_QDR 0x014
#define MCFQSPI_QCR 0x014
#define MCFQSPI_QCR_CONT 0x8000
#define MCFQSPI_QCR_BITSE 0x4000
#define MCFQSPI_QCR_DT 0x2000
struct mcfqspi {
void __iomem *iobase;
int irq;
struct clk *clk;
struct mcfqspi_cs_control *cs_control;
wait_queue_head_t waitq;
struct device *dev;
};
static void mcfqspi_wr_qmr(struct mcfqspi *mcfqspi, u16 val)
{
writew(val, mcfqspi->iobase + MCFQSPI_QMR);
}
static void mcfqspi_wr_qdlyr(struct mcfqspi *mcfqspi, u16 val)
{
writew(val, mcfqspi->iobase + MCFQSPI_QDLYR);
}
static u16 mcfqspi_rd_qdlyr(struct mcfqspi *mcfqspi)
{
return readw(mcfqspi->iobase + MCFQSPI_QDLYR);
}
static void mcfqspi_wr_qwr(struct mcfqspi *mcfqspi, u16 val)
{
writew(val, mcfqspi->iobase + MCFQSPI_QWR);
}
static void mcfqspi_wr_qir(struct mcfqspi *mcfqspi, u16 val)
{
writew(val, mcfqspi->iobase + MCFQSPI_QIR);
}
static void mcfqspi_wr_qar(struct mcfqspi *mcfqspi, u16 val)
{
writew(val, mcfqspi->iobase + MCFQSPI_QAR);
}
static void mcfqspi_wr_qdr(struct mcfqspi *mcfqspi, u16 val)
{
writew(val, mcfqspi->iobase + MCFQSPI_QDR);
}
static u16 mcfqspi_rd_qdr(struct mcfqspi *mcfqspi)
{
return readw(mcfqspi->iobase + MCFQSPI_QDR);
}
static void mcfqspi_cs_select(struct mcfqspi *mcfqspi, u8 chip_select,
bool cs_high)
{
mcfqspi->cs_control->select(mcfqspi->cs_control, chip_select, cs_high);
}
static void mcfqspi_cs_deselect(struct mcfqspi *mcfqspi, u8 chip_select,
bool cs_high)
{
mcfqspi->cs_control->deselect(mcfqspi->cs_control, chip_select, cs_high);
}
static int mcfqspi_cs_setup(struct mcfqspi *mcfqspi)
{
return (mcfqspi->cs_control && mcfqspi->cs_control->setup) ?
mcfqspi->cs_control->setup(mcfqspi->cs_control) : 0;
}
static void mcfqspi_cs_teardown(struct mcfqspi *mcfqspi)
{
if (mcfqspi->cs_control && mcfqspi->cs_control->teardown)
mcfqspi->cs_control->teardown(mcfqspi->cs_control);
}
static u8 mcfqspi_qmr_baud(u32 speed_hz)
{
return clamp((MCFQSPI_BUSCLK + speed_hz - 1) / speed_hz, 2u, 255u);
}
static bool mcfqspi_qdlyr_spe(struct mcfqspi *mcfqspi)
{
return mcfqspi_rd_qdlyr(mcfqspi) & MCFQSPI_QDLYR_SPE;
}
static irqreturn_t mcfqspi_irq_handler(int this_irq, void *dev_id)
{
struct mcfqspi *mcfqspi = dev_id;
/* clear interrupt */
mcfqspi_wr_qir(mcfqspi, MCFQSPI_QIR_SPIFE | MCFQSPI_QIR_SPIF);
wake_up(&mcfqspi->waitq);
return IRQ_HANDLED;
}
static void mcfqspi_transfer_msg8(struct mcfqspi *mcfqspi, unsigned count,
const u8 *txbuf, u8 *rxbuf)
{
unsigned i, n, offset = 0;
n = min(count, 16u);
mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_CMDBUF);
for (i = 0; i < n; ++i)
mcfqspi_wr_qdr(mcfqspi, MCFQSPI_QCR_BITSE);
mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_TXBUF);
if (txbuf)
for (i = 0; i < n; ++i)
mcfqspi_wr_qdr(mcfqspi, *txbuf++);
else
for (i = 0; i < count; ++i)
mcfqspi_wr_qdr(mcfqspi, 0);
count -= n;
if (count) {
u16 qwr = 0xf08;
mcfqspi_wr_qwr(mcfqspi, 0x700);
mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
do {
wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi));
mcfqspi_wr_qwr(mcfqspi, qwr);
mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
if (rxbuf) {
mcfqspi_wr_qar(mcfqspi,
MCFQSPI_QAR_RXBUF + offset);
for (i = 0; i < 8; ++i)
*rxbuf++ = mcfqspi_rd_qdr(mcfqspi);
}
n = min(count, 8u);
if (txbuf) {
mcfqspi_wr_qar(mcfqspi,
MCFQSPI_QAR_TXBUF + offset);
for (i = 0; i < n; ++i)
mcfqspi_wr_qdr(mcfqspi, *txbuf++);
}
qwr = (offset ? 0x808 : 0) + ((n - 1) << 8);
offset ^= 8;
count -= n;
} while (count);
wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi));
mcfqspi_wr_qwr(mcfqspi, qwr);
mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
if (rxbuf) {
mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_RXBUF + offset);
for (i = 0; i < 8; ++i)
*rxbuf++ = mcfqspi_rd_qdr(mcfqspi);
offset ^= 8;
}
} else {
mcfqspi_wr_qwr(mcfqspi, (n - 1) << 8);
mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
}
wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi));
if (rxbuf) {
mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_RXBUF + offset);
for (i = 0; i < n; ++i)
*rxbuf++ = mcfqspi_rd_qdr(mcfqspi);
}
}
static void mcfqspi_transfer_msg16(struct mcfqspi *mcfqspi, unsigned count,
const u16 *txbuf, u16 *rxbuf)
{
unsigned i, n, offset = 0;
n = min(count, 16u);
mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_CMDBUF);
for (i = 0; i < n; ++i)
mcfqspi_wr_qdr(mcfqspi, MCFQSPI_QCR_BITSE);
mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_TXBUF);
if (txbuf)
for (i = 0; i < n; ++i)
mcfqspi_wr_qdr(mcfqspi, *txbuf++);
else
for (i = 0; i < count; ++i)
mcfqspi_wr_qdr(mcfqspi, 0);
count -= n;
if (count) {
u16 qwr = 0xf08;
mcfqspi_wr_qwr(mcfqspi, 0x700);
mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
do {
wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi));
mcfqspi_wr_qwr(mcfqspi, qwr);
mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
if (rxbuf) {
mcfqspi_wr_qar(mcfqspi,
MCFQSPI_QAR_RXBUF + offset);
for (i = 0; i < 8; ++i)
*rxbuf++ = mcfqspi_rd_qdr(mcfqspi);
}
n = min(count, 8u);
if (txbuf) {
mcfqspi_wr_qar(mcfqspi,
MCFQSPI_QAR_TXBUF + offset);
for (i = 0; i < n; ++i)
mcfqspi_wr_qdr(mcfqspi, *txbuf++);
}
qwr = (offset ? 0x808 : 0x000) + ((n - 1) << 8);
offset ^= 8;
count -= n;
} while (count);
wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi));
mcfqspi_wr_qwr(mcfqspi, qwr);
mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
if (rxbuf) {
mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_RXBUF + offset);
for (i = 0; i < 8; ++i)
*rxbuf++ = mcfqspi_rd_qdr(mcfqspi);
offset ^= 8;
}
} else {
mcfqspi_wr_qwr(mcfqspi, (n - 1) << 8);
mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
}
wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi));
if (rxbuf) {
mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_RXBUF + offset);
for (i = 0; i < n; ++i)
*rxbuf++ = mcfqspi_rd_qdr(mcfqspi);
}
}
static int mcfqspi_transfer_one_message(struct spi_master *master,
struct spi_message *msg)
{
struct mcfqspi *mcfqspi = spi_master_get_devdata(master);
struct spi_device *spi = msg->spi;
struct spi_transfer *t;
int status = 0;
list_for_each_entry(t, &msg->transfers, transfer_list) {
bool cs_high = spi->mode & SPI_CS_HIGH;
u16 qmr = MCFQSPI_QMR_MSTR;
if (t->bits_per_word)
qmr |= t->bits_per_word << 10;
else
qmr |= spi->bits_per_word << 10;
if (spi->mode & SPI_CPHA)
qmr |= MCFQSPI_QMR_CPHA;
if (spi->mode & SPI_CPOL)
qmr |= MCFQSPI_QMR_CPOL;
if (t->speed_hz)
qmr |= mcfqspi_qmr_baud(t->speed_hz);
else
qmr |= mcfqspi_qmr_baud(spi->max_speed_hz);
mcfqspi_wr_qmr(mcfqspi, qmr);
mcfqspi_cs_select(mcfqspi, spi->chip_select, cs_high);
mcfqspi_wr_qir(mcfqspi, MCFQSPI_QIR_SPIFE);
if (t->bits_per_word == 8)
mcfqspi_transfer_msg8(mcfqspi, t->len, t->tx_buf,
t->rx_buf);
else
mcfqspi_transfer_msg16(mcfqspi, t->len / 2, t->tx_buf,
t->rx_buf);
mcfqspi_wr_qir(mcfqspi, 0);
if (t->delay_usecs)
udelay(t->delay_usecs);
if (t->cs_change) {
if (!list_is_last(&t->transfer_list, &msg->transfers))
mcfqspi_cs_deselect(mcfqspi, spi->chip_select,
cs_high);
} else {
if (list_is_last(&t->transfer_list, &msg->transfers))
mcfqspi_cs_deselect(mcfqspi, spi->chip_select,
cs_high);
}
msg->actual_length += t->len;
}
msg->status = status;
spi_finalize_current_message(master);
return status;
}
static int mcfqspi_prepare_transfer_hw(struct spi_master *master)
{
struct mcfqspi *mcfqspi = spi_master_get_devdata(master);
pm_runtime_get_sync(mcfqspi->dev);
return 0;
}
static int mcfqspi_unprepare_transfer_hw(struct spi_master *master)
{
struct mcfqspi *mcfqspi = spi_master_get_devdata(master);
pm_runtime_put_sync(mcfqspi->dev);
return 0;
}
static int mcfqspi_setup(struct spi_device *spi)
{
if ((spi->bits_per_word < 8) || (spi->bits_per_word > 16)) {
dev_dbg(&spi->dev, "%d bits per word is not supported\n",
spi->bits_per_word);
return -EINVAL;
}
if (spi->chip_select >= spi->master->num_chipselect) {
dev_dbg(&spi->dev, "%d chip select is out of range\n",
spi->chip_select);
return -EINVAL;
}
mcfqspi_cs_deselect(spi_master_get_devdata(spi->master),
spi->chip_select, spi->mode & SPI_CS_HIGH);
dev_dbg(&spi->dev,
"bits per word %d, chip select %d, speed %d KHz\n",
spi->bits_per_word, spi->chip_select,
(MCFQSPI_BUSCLK / mcfqspi_qmr_baud(spi->max_speed_hz))
/ 1000);
return 0;
}
static int mcfqspi_probe(struct platform_device *pdev)
{
struct spi_master *master;
struct mcfqspi *mcfqspi;
struct resource *res;
struct mcfqspi_platform_data *pdata;
int status;
master = spi_alloc_master(&pdev->dev, sizeof(*mcfqspi));
if (master == NULL) {
dev_dbg(&pdev->dev, "spi_alloc_master failed\n");
return -ENOMEM;
}
mcfqspi = spi_master_get_devdata(master);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
dev_dbg(&pdev->dev, "platform_get_resource failed\n");
status = -ENXIO;
goto fail0;
}
if (!request_mem_region(res->start, resource_size(res), pdev->name)) {
dev_dbg(&pdev->dev, "request_mem_region failed\n");
status = -EBUSY;
goto fail0;
}
mcfqspi->iobase = ioremap(res->start, resource_size(res));
if (!mcfqspi->iobase) {
dev_dbg(&pdev->dev, "ioremap failed\n");
status = -ENOMEM;
goto fail1;
}
mcfqspi->irq = platform_get_irq(pdev, 0);
if (mcfqspi->irq < 0) {
dev_dbg(&pdev->dev, "platform_get_irq failed\n");
status = -ENXIO;
goto fail2;
}
status = request_irq(mcfqspi->irq, mcfqspi_irq_handler, 0,
pdev->name, mcfqspi);
if (status) {
dev_dbg(&pdev->dev, "request_irq failed\n");
goto fail2;
}
mcfqspi->clk = clk_get(&pdev->dev, "qspi_clk");
if (IS_ERR(mcfqspi->clk)) {
dev_dbg(&pdev->dev, "clk_get failed\n");
status = PTR_ERR(mcfqspi->clk);
goto fail3;
}
clk_enable(mcfqspi->clk);
pdata = pdev->dev.platform_data;
if (!pdata) {
dev_dbg(&pdev->dev, "platform data is missing\n");
goto fail4;
}
master->bus_num = pdata->bus_num;
master->num_chipselect = pdata->num_chipselect;
mcfqspi->cs_control = pdata->cs_control;
status = mcfqspi_cs_setup(mcfqspi);
if (status) {
dev_dbg(&pdev->dev, "error initializing cs_control\n");
goto fail4;
}
init_waitqueue_head(&mcfqspi->waitq);
mcfqspi->dev = &pdev->dev;
master->mode_bits = SPI_CS_HIGH | SPI_CPOL | SPI_CPHA;
master->setup = mcfqspi_setup;
master->transfer_one_message = mcfqspi_transfer_one_message;
master->prepare_transfer_hardware = mcfqspi_prepare_transfer_hw;
master->unprepare_transfer_hardware = mcfqspi_unprepare_transfer_hw;
platform_set_drvdata(pdev, master);
status = spi_register_master(master);
if (status) {
dev_dbg(&pdev->dev, "spi_register_master failed\n");
goto fail5;
}
pm_runtime_enable(mcfqspi->dev);
dev_info(&pdev->dev, "Coldfire QSPI bus driver\n");
return 0;
fail5:
mcfqspi_cs_teardown(mcfqspi);
fail4:
clk_disable(mcfqspi->clk);
clk_put(mcfqspi->clk);
fail3:
free_irq(mcfqspi->irq, mcfqspi);
fail2:
iounmap(mcfqspi->iobase);
fail1:
release_mem_region(res->start, resource_size(res));
fail0:
spi_master_put(master);
dev_dbg(&pdev->dev, "Coldfire QSPI probe failed\n");
return status;
}
static int mcfqspi_remove(struct platform_device *pdev)
{
struct spi_master *master = platform_get_drvdata(pdev);
struct mcfqspi *mcfqspi = spi_master_get_devdata(master);
struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
pm_runtime_disable(mcfqspi->dev);
/* disable the hardware (set the baud rate to 0) */
mcfqspi_wr_qmr(mcfqspi, MCFQSPI_QMR_MSTR);
platform_set_drvdata(pdev, NULL);
mcfqspi_cs_teardown(mcfqspi);
clk_disable(mcfqspi->clk);
clk_put(mcfqspi->clk);
free_irq(mcfqspi->irq, mcfqspi);
iounmap(mcfqspi->iobase);
release_mem_region(res->start, resource_size(res));
spi_unregister_master(master);
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int mcfqspi_suspend(struct device *dev)
{
struct spi_master *master = dev_get_drvdata(dev);
struct mcfqspi *mcfqspi = spi_master_get_devdata(master);
spi_master_suspend(master);
clk_disable(mcfqspi->clk);
return 0;
}
static int mcfqspi_resume(struct device *dev)
{
struct spi_master *master = dev_get_drvdata(dev);
struct mcfqspi *mcfqspi = spi_master_get_devdata(master);
spi_master_resume(master);
clk_enable(mcfqspi->clk);
return 0;
}
#endif
#ifdef CONFIG_PM_RUNTIME
static int mcfqspi_runtime_suspend(struct device *dev)
{
struct mcfqspi *mcfqspi = platform_get_drvdata(to_platform_device(dev));
clk_disable(mcfqspi->clk);
return 0;
}
static int mcfqspi_runtime_resume(struct device *dev)
{
struct mcfqspi *mcfqspi = platform_get_drvdata(to_platform_device(dev));
clk_enable(mcfqspi->clk);
return 0;
}
#endif
static const struct dev_pm_ops mcfqspi_pm = {
SET_SYSTEM_SLEEP_PM_OPS(mcfqspi_suspend, mcfqspi_resume)
SET_RUNTIME_PM_OPS(mcfqspi_runtime_suspend, mcfqspi_runtime_resume,
NULL)
};
static struct platform_driver mcfqspi_driver = {
.driver.name = DRIVER_NAME,
.driver.owner = THIS_MODULE,
.driver.pm = &mcfqspi_pm,
.probe = mcfqspi_probe,
.remove = mcfqspi_remove,
};
module_platform_driver(mcfqspi_driver);
MODULE_AUTHOR("Steven King <sfking@fdwdc.com>");
MODULE_DESCRIPTION("Coldfire QSPI Controller Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:" DRIVER_NAME);
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