- 根目录:
- drivers
- spi
- spi-coldfire-qspi.c
/*
* 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.
*/
#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;
};
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->setup) ?
mcfqspi->cs_control->setup(mcfqspi->cs_control) : 0;
}
static void mcfqspi_cs_teardown(struct mcfqspi *mcfqspi)
{
if (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 void mcfqspi_set_cs(struct spi_device *spi, bool enable)
{
struct mcfqspi *mcfqspi = spi_master_get_devdata(spi->master);
bool cs_high = spi->mode & SPI_CS_HIGH;
if (enable)
mcfqspi_cs_select(mcfqspi, spi->chip_select, cs_high);
else
mcfqspi_cs_deselect(mcfqspi, spi->chip_select, cs_high);
}
static int mcfqspi_transfer_one(struct spi_master *master,
struct spi_device *spi,
struct spi_transfer *t)
{
struct mcfqspi *mcfqspi = spi_master_get_devdata(master);
u16 qmr = MCFQSPI_QMR_MSTR;
qmr |= t->bits_per_word << 10;
if (spi->mode & SPI_CPHA)
qmr |= MCFQSPI_QMR_CPHA;
if (spi->mode & SPI_CPOL)
qmr |= MCFQSPI_QMR_CPOL;
qmr |= mcfqspi_qmr_baud(t->speed_hz);
mcfqspi_wr_qmr(mcfqspi, qmr);
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);
return 0;
}
static int mcfqspi_setup(struct spi_device *spi)
{
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;
pdata = dev_get_platdata(&pdev->dev);
if (!pdata) {
dev_dbg(&pdev->dev, "platform data is missing\n");
return -ENOENT;
}
if (!pdata->cs_control) {
dev_dbg(&pdev->dev, "pdata->cs_control is NULL\n");
return -EINVAL;
}
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);
mcfqspi->iobase = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(mcfqspi->iobase)) {
status = PTR_ERR(mcfqspi->iobase);
goto fail0;
}
mcfqspi->irq = platform_get_irq(pdev, 0);
if (mcfqspi->irq < 0) {
dev_dbg(&pdev->dev, "platform_get_irq failed\n");
status = -ENXIO;
goto fail0;
}
status = devm_request_irq(&pdev->dev, mcfqspi->irq, mcfqspi_irq_handler,
0, pdev->name, mcfqspi);
if (status) {
dev_dbg(&pdev->dev, "request_irq failed\n");
goto fail0;
}
mcfqspi->clk = devm_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 fail0;
}
clk_enable(mcfqspi->clk);
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 fail1;
}
init_waitqueue_head(&mcfqspi->waitq);
master->mode_bits = SPI_CS_HIGH | SPI_CPOL | SPI_CPHA;
master->bits_per_word_mask = SPI_BPW_RANGE_MASK(8, 16);
master->setup = mcfqspi_setup;
master->set_cs = mcfqspi_set_cs;
master->transfer_one = mcfqspi_transfer_one;
master->auto_runtime_pm = true;
platform_set_drvdata(pdev, master);
pm_runtime_enable(&pdev->dev);
status = devm_spi_register_master(&pdev->dev, master);
if (status) {
dev_dbg(&pdev->dev, "spi_register_master failed\n");
goto fail2;
}
dev_info(&pdev->dev, "Coldfire QSPI bus driver\n");
return 0;
fail2:
pm_runtime_disable(&pdev->dev);
mcfqspi_cs_teardown(mcfqspi);
fail1:
clk_disable(mcfqspi->clk);
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);
pm_runtime_disable(&pdev->dev);
/* disable the hardware (set the baud rate to 0) */
mcfqspi_wr_qmr(mcfqspi, MCFQSPI_QMR_MSTR);
mcfqspi_cs_teardown(mcfqspi);
clk_disable(mcfqspi->clk);
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);
int ret;
ret = spi_master_suspend(master);
if (ret)
return ret;
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);
clk_enable(mcfqspi->clk);
return spi_master_resume(master);
}
#endif
#ifdef CONFIG_PM
static int mcfqspi_runtime_suspend(struct device *dev)
{
struct spi_master *master = dev_get_drvdata(dev);
struct mcfqspi *mcfqspi = spi_master_get_devdata(master);
clk_disable(mcfqspi->clk);
return 0;
}
static int mcfqspi_runtime_resume(struct device *dev)
{
struct spi_master *master = dev_get_drvdata(dev);
struct mcfqspi *mcfqspi = spi_master_get_devdata(master);
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);