linux/drivers/spi/spi_imx.c

690 lines
17 KiB
C
Raw Normal View History

/*
* Copyright 2004-2007 Freescale Semiconductor, Inc. All Rights Reserved.
* Copyright (C) 2008 Juergen Beisert
*
* 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
* 51 Franklin Street, Fifth Floor
* Boston, MA 02110-1301, USA.
*/
#include <linux/clk.h>
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/gpio.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/spi/spi.h>
#include <linux/spi/spi_bitbang.h>
#include <linux/types.h>
#include <mach/spi.h>
#define DRIVER_NAME "spi_imx"
#define MXC_CSPIRXDATA 0x00
#define MXC_CSPITXDATA 0x04
#define MXC_CSPICTRL 0x08
#define MXC_CSPIINT 0x0c
#define MXC_RESET 0x1c
#define MX3_CSPISTAT 0x14
#define MX3_CSPISTAT_RR (1 << 3)
/* generic defines to abstract from the different register layouts */
#define MXC_INT_RR (1 << 0) /* Receive data ready interrupt */
#define MXC_INT_TE (1 << 1) /* Transmit FIFO empty interrupt */
struct spi_imx_config {
unsigned int speed_hz;
unsigned int bpw;
unsigned int mode;
int cs;
};
struct spi_imx_data {
struct spi_bitbang bitbang;
struct completion xfer_done;
void *base;
int irq;
struct clk *clk;
unsigned long spi_clk;
int *chipselect;
unsigned int count;
void (*tx)(struct spi_imx_data *);
void (*rx)(struct spi_imx_data *);
void *rx_buf;
const void *tx_buf;
unsigned int txfifo; /* number of words pushed in tx FIFO */
/* SoC specific functions */
void (*intctrl)(struct spi_imx_data *, int);
int (*config)(struct spi_imx_data *, struct spi_imx_config *);
void (*trigger)(struct spi_imx_data *);
int (*rx_available)(struct spi_imx_data *);
};
#define MXC_SPI_BUF_RX(type) \
static void spi_imx_buf_rx_##type(struct spi_imx_data *spi_imx) \
{ \
unsigned int val = readl(spi_imx->base + MXC_CSPIRXDATA); \
\
if (spi_imx->rx_buf) { \
*(type *)spi_imx->rx_buf = val; \
spi_imx->rx_buf += sizeof(type); \
} \
}
#define MXC_SPI_BUF_TX(type) \
static void spi_imx_buf_tx_##type(struct spi_imx_data *spi_imx) \
{ \
type val = 0; \
\
if (spi_imx->tx_buf) { \
val = *(type *)spi_imx->tx_buf; \
spi_imx->tx_buf += sizeof(type); \
} \
\
spi_imx->count -= sizeof(type); \
\
writel(val, spi_imx->base + MXC_CSPITXDATA); \
}
MXC_SPI_BUF_RX(u8)
MXC_SPI_BUF_TX(u8)
MXC_SPI_BUF_RX(u16)
MXC_SPI_BUF_TX(u16)
MXC_SPI_BUF_RX(u32)
MXC_SPI_BUF_TX(u32)
/* First entry is reserved, second entry is valid only if SDHC_SPIEN is set
* (which is currently not the case in this driver)
*/
static int mxc_clkdivs[] = {0, 3, 4, 6, 8, 12, 16, 24, 32, 48, 64, 96, 128, 192,
256, 384, 512, 768, 1024};
/* MX21, MX27 */
static unsigned int spi_imx_clkdiv_1(unsigned int fin,
unsigned int fspi)
{
int i, max;
if (cpu_is_mx21())
max = 18;
else
max = 16;
for (i = 2; i < max; i++)
if (fspi * mxc_clkdivs[i] >= fin)
return i;
return max;
}
/* MX1, MX31, MX35 */
static unsigned int spi_imx_clkdiv_2(unsigned int fin,
unsigned int fspi)
{
int i, div = 4;
for (i = 0; i < 7; i++) {
if (fspi * div >= fin)
return i;
div <<= 1;
}
return 7;
}
#define MX31_INTREG_TEEN (1 << 0)
#define MX31_INTREG_RREN (1 << 3)
#define MX31_CSPICTRL_ENABLE (1 << 0)
#define MX31_CSPICTRL_MASTER (1 << 1)
#define MX31_CSPICTRL_XCH (1 << 2)
#define MX31_CSPICTRL_POL (1 << 4)
#define MX31_CSPICTRL_PHA (1 << 5)
#define MX31_CSPICTRL_SSCTL (1 << 6)
#define MX31_CSPICTRL_SSPOL (1 << 7)
#define MX31_CSPICTRL_BC_SHIFT 8
#define MX35_CSPICTRL_BL_SHIFT 20
#define MX31_CSPICTRL_CS_SHIFT 24
#define MX35_CSPICTRL_CS_SHIFT 12
#define MX31_CSPICTRL_DR_SHIFT 16
#define MX31_CSPISTATUS 0x14
#define MX31_STATUS_RR (1 << 3)
/* These functions also work for the i.MX35, but be aware that
* the i.MX35 has a slightly different register layout for bits
* we do not use here.
*/
static void mx31_intctrl(struct spi_imx_data *spi_imx, int enable)
{
unsigned int val = 0;
if (enable & MXC_INT_TE)
val |= MX31_INTREG_TEEN;
if (enable & MXC_INT_RR)
val |= MX31_INTREG_RREN;
writel(val, spi_imx->base + MXC_CSPIINT);
}
static void mx31_trigger(struct spi_imx_data *spi_imx)
{
unsigned int reg;
reg = readl(spi_imx->base + MXC_CSPICTRL);
reg |= MX31_CSPICTRL_XCH;
writel(reg, spi_imx->base + MXC_CSPICTRL);
}
static int mx31_config(struct spi_imx_data *spi_imx,
struct spi_imx_config *config)
{
unsigned int reg = MX31_CSPICTRL_ENABLE | MX31_CSPICTRL_MASTER;
reg |= spi_imx_clkdiv_2(spi_imx->spi_clk, config->speed_hz) <<
MX31_CSPICTRL_DR_SHIFT;
if (cpu_is_mx31())
reg |= (config->bpw - 1) << MX31_CSPICTRL_BC_SHIFT;
else if (cpu_is_mx25() || cpu_is_mx35()) {
reg |= (config->bpw - 1) << MX35_CSPICTRL_BL_SHIFT;
reg |= MX31_CSPICTRL_SSCTL;
}
if (config->mode & SPI_CPHA)
reg |= MX31_CSPICTRL_PHA;
if (config->mode & SPI_CPOL)
reg |= MX31_CSPICTRL_POL;
if (config->mode & SPI_CS_HIGH)
reg |= MX31_CSPICTRL_SSPOL;
if (config->cs < 0) {
if (cpu_is_mx31())
reg |= (config->cs + 32) << MX31_CSPICTRL_CS_SHIFT;
else if (cpu_is_mx25() || cpu_is_mx35())
reg |= (config->cs + 32) << MX35_CSPICTRL_CS_SHIFT;
}
writel(reg, spi_imx->base + MXC_CSPICTRL);
return 0;
}
static int mx31_rx_available(struct spi_imx_data *spi_imx)
{
return readl(spi_imx->base + MX31_CSPISTATUS) & MX31_STATUS_RR;
}
#define MX27_INTREG_RR (1 << 4)
#define MX27_INTREG_TEEN (1 << 9)
#define MX27_INTREG_RREN (1 << 13)
#define MX27_CSPICTRL_POL (1 << 5)
#define MX27_CSPICTRL_PHA (1 << 6)
#define MX27_CSPICTRL_SSPOL (1 << 8)
#define MX27_CSPICTRL_XCH (1 << 9)
#define MX27_CSPICTRL_ENABLE (1 << 10)
#define MX27_CSPICTRL_MASTER (1 << 11)
#define MX27_CSPICTRL_DR_SHIFT 14
#define MX27_CSPICTRL_CS_SHIFT 19
static void mx27_intctrl(struct spi_imx_data *spi_imx, int enable)
{
unsigned int val = 0;
if (enable & MXC_INT_TE)
val |= MX27_INTREG_TEEN;
if (enable & MXC_INT_RR)
val |= MX27_INTREG_RREN;
writel(val, spi_imx->base + MXC_CSPIINT);
}
static void mx27_trigger(struct spi_imx_data *spi_imx)
{
unsigned int reg;
reg = readl(spi_imx->base + MXC_CSPICTRL);
reg |= MX27_CSPICTRL_XCH;
writel(reg, spi_imx->base + MXC_CSPICTRL);
}
static int mx27_config(struct spi_imx_data *spi_imx,
struct spi_imx_config *config)
{
unsigned int reg = MX27_CSPICTRL_ENABLE | MX27_CSPICTRL_MASTER;
reg |= spi_imx_clkdiv_1(spi_imx->spi_clk, config->speed_hz) <<
MX27_CSPICTRL_DR_SHIFT;
reg |= config->bpw - 1;
if (config->mode & SPI_CPHA)
reg |= MX27_CSPICTRL_PHA;
if (config->mode & SPI_CPOL)
reg |= MX27_CSPICTRL_POL;
if (config->mode & SPI_CS_HIGH)
reg |= MX27_CSPICTRL_SSPOL;
if (config->cs < 0)
reg |= (config->cs + 32) << MX27_CSPICTRL_CS_SHIFT;
writel(reg, spi_imx->base + MXC_CSPICTRL);
return 0;
}
static int mx27_rx_available(struct spi_imx_data *spi_imx)
{
return readl(spi_imx->base + MXC_CSPIINT) & MX27_INTREG_RR;
}
#define MX1_INTREG_RR (1 << 3)
#define MX1_INTREG_TEEN (1 << 8)
#define MX1_INTREG_RREN (1 << 11)
#define MX1_CSPICTRL_POL (1 << 4)
#define MX1_CSPICTRL_PHA (1 << 5)
#define MX1_CSPICTRL_XCH (1 << 8)
#define MX1_CSPICTRL_ENABLE (1 << 9)
#define MX1_CSPICTRL_MASTER (1 << 10)
#define MX1_CSPICTRL_DR_SHIFT 13
static void mx1_intctrl(struct spi_imx_data *spi_imx, int enable)
{
unsigned int val = 0;
if (enable & MXC_INT_TE)
val |= MX1_INTREG_TEEN;
if (enable & MXC_INT_RR)
val |= MX1_INTREG_RREN;
writel(val, spi_imx->base + MXC_CSPIINT);
}
static void mx1_trigger(struct spi_imx_data *spi_imx)
{
unsigned int reg;
reg = readl(spi_imx->base + MXC_CSPICTRL);
reg |= MX1_CSPICTRL_XCH;
writel(reg, spi_imx->base + MXC_CSPICTRL);
}
static int mx1_config(struct spi_imx_data *spi_imx,
struct spi_imx_config *config)
{
unsigned int reg = MX1_CSPICTRL_ENABLE | MX1_CSPICTRL_MASTER;
reg |= spi_imx_clkdiv_2(spi_imx->spi_clk, config->speed_hz) <<
MX1_CSPICTRL_DR_SHIFT;
reg |= config->bpw - 1;
if (config->mode & SPI_CPHA)
reg |= MX1_CSPICTRL_PHA;
if (config->mode & SPI_CPOL)
reg |= MX1_CSPICTRL_POL;
writel(reg, spi_imx->base + MXC_CSPICTRL);
return 0;
}
static int mx1_rx_available(struct spi_imx_data *spi_imx)
{
return readl(spi_imx->base + MXC_CSPIINT) & MX1_INTREG_RR;
}
static void spi_imx_chipselect(struct spi_device *spi, int is_active)
{
struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
int gpio = spi_imx->chipselect[spi->chip_select];
int active = is_active != BITBANG_CS_INACTIVE;
int dev_is_lowactive = !(spi->mode & SPI_CS_HIGH);
if (gpio < 0)
return;
gpio_set_value(gpio, dev_is_lowactive ^ active);
}
static void spi_imx_push(struct spi_imx_data *spi_imx)
{
while (spi_imx->txfifo < 8) {
if (!spi_imx->count)
break;
spi_imx->tx(spi_imx);
spi_imx->txfifo++;
}
spi_imx->trigger(spi_imx);
}
static irqreturn_t spi_imx_isr(int irq, void *dev_id)
{
struct spi_imx_data *spi_imx = dev_id;
while (spi_imx->rx_available(spi_imx)) {
spi_imx->rx(spi_imx);
spi_imx->txfifo--;
}
if (spi_imx->count) {
spi_imx_push(spi_imx);
return IRQ_HANDLED;
}
if (spi_imx->txfifo) {
/* No data left to push, but still waiting for rx data,
* enable receive data available interrupt.
*/
spi_imx->intctrl(spi_imx, MXC_INT_RR);
return IRQ_HANDLED;
}
spi_imx->intctrl(spi_imx, 0);
complete(&spi_imx->xfer_done);
return IRQ_HANDLED;
}
static int spi_imx_setupxfer(struct spi_device *spi,
struct spi_transfer *t)
{
struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
struct spi_imx_config config;
config.bpw = t ? t->bits_per_word : spi->bits_per_word;
config.speed_hz = t ? t->speed_hz : spi->max_speed_hz;
config.mode = spi->mode;
config.cs = spi_imx->chipselect[spi->chip_select];
if (!config.speed_hz)
config.speed_hz = spi->max_speed_hz;
if (!config.bpw)
config.bpw = spi->bits_per_word;
if (!config.speed_hz)
config.speed_hz = spi->max_speed_hz;
/* Initialize the functions for transfer */
if (config.bpw <= 8) {
spi_imx->rx = spi_imx_buf_rx_u8;
spi_imx->tx = spi_imx_buf_tx_u8;
} else if (config.bpw <= 16) {
spi_imx->rx = spi_imx_buf_rx_u16;
spi_imx->tx = spi_imx_buf_tx_u16;
} else if (config.bpw <= 32) {
spi_imx->rx = spi_imx_buf_rx_u32;
spi_imx->tx = spi_imx_buf_tx_u32;
} else
BUG();
spi_imx->config(spi_imx, &config);
return 0;
}
static int spi_imx_transfer(struct spi_device *spi,
struct spi_transfer *transfer)
{
struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
spi_imx->tx_buf = transfer->tx_buf;
spi_imx->rx_buf = transfer->rx_buf;
spi_imx->count = transfer->len;
spi_imx->txfifo = 0;
init_completion(&spi_imx->xfer_done);
spi_imx_push(spi_imx);
spi_imx->intctrl(spi_imx, MXC_INT_TE);
wait_for_completion(&spi_imx->xfer_done);
return transfer->len;
}
static int spi_imx_setup(struct spi_device *spi)
{
struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
int gpio = spi_imx->chipselect[spi->chip_select];
pr_debug("%s: mode %d, %u bpw, %d hz\n", __func__,
spi->mode, spi->bits_per_word, spi->max_speed_hz);
if (gpio >= 0)
gpio_direction_output(gpio, spi->mode & SPI_CS_HIGH ? 0 : 1);
spi_imx_chipselect(spi, BITBANG_CS_INACTIVE);
return 0;
}
static void spi_imx_cleanup(struct spi_device *spi)
{
}
static int __init spi_imx_probe(struct platform_device *pdev)
{
struct spi_imx_master *mxc_platform_info;
struct spi_master *master;
struct spi_imx_data *spi_imx;
struct resource *res;
int i, ret;
mxc_platform_info = dev_get_platdata(&pdev->dev);
if (!mxc_platform_info) {
dev_err(&pdev->dev, "can't get the platform data\n");
return -EINVAL;
}
master = spi_alloc_master(&pdev->dev, sizeof(struct spi_imx_data));
if (!master)
return -ENOMEM;
platform_set_drvdata(pdev, master);
master->bus_num = pdev->id;
master->num_chipselect = mxc_platform_info->num_chipselect;
spi_imx = spi_master_get_devdata(master);
spi_imx->bitbang.master = spi_master_get(master);
spi_imx->chipselect = mxc_platform_info->chipselect;
for (i = 0; i < master->num_chipselect; i++) {
if (spi_imx->chipselect[i] < 0)
continue;
ret = gpio_request(spi_imx->chipselect[i], DRIVER_NAME);
if (ret) {
while (i > 0) {
i--;
if (spi_imx->chipselect[i] >= 0)
gpio_free(spi_imx->chipselect[i]);
}
dev_err(&pdev->dev, "can't get cs gpios\n");
goto out_master_put;
}
}
spi_imx->bitbang.chipselect = spi_imx_chipselect;
spi_imx->bitbang.setup_transfer = spi_imx_setupxfer;
spi_imx->bitbang.txrx_bufs = spi_imx_transfer;
spi_imx->bitbang.master->setup = spi_imx_setup;
spi_imx->bitbang.master->cleanup = spi_imx_cleanup;
spi_imx->bitbang.master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
init_completion(&spi_imx->xfer_done);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
dev_err(&pdev->dev, "can't get platform resource\n");
ret = -ENOMEM;
goto out_gpio_free;
}
if (!request_mem_region(res->start, resource_size(res), pdev->name)) {
dev_err(&pdev->dev, "request_mem_region failed\n");
ret = -EBUSY;
goto out_gpio_free;
}
spi_imx->base = ioremap(res->start, resource_size(res));
if (!spi_imx->base) {
ret = -EINVAL;
goto out_release_mem;
}
spi_imx->irq = platform_get_irq(pdev, 0);
if (spi_imx->irq <= 0) {
ret = -EINVAL;
goto out_iounmap;
}
ret = request_irq(spi_imx->irq, spi_imx_isr, 0, DRIVER_NAME, spi_imx);
if (ret) {
dev_err(&pdev->dev, "can't get irq%d: %d\n", spi_imx->irq, ret);
goto out_iounmap;
}
if (cpu_is_mx25() || cpu_is_mx31() || cpu_is_mx35()) {
spi_imx->intctrl = mx31_intctrl;
spi_imx->config = mx31_config;
spi_imx->trigger = mx31_trigger;
spi_imx->rx_available = mx31_rx_available;
} else if (cpu_is_mx27() || cpu_is_mx21()) {
spi_imx->intctrl = mx27_intctrl;
spi_imx->config = mx27_config;
spi_imx->trigger = mx27_trigger;
spi_imx->rx_available = mx27_rx_available;
} else if (cpu_is_mx1()) {
spi_imx->intctrl = mx1_intctrl;
spi_imx->config = mx1_config;
spi_imx->trigger = mx1_trigger;
spi_imx->rx_available = mx1_rx_available;
} else
BUG();
spi_imx->clk = clk_get(&pdev->dev, NULL);
if (IS_ERR(spi_imx->clk)) {
dev_err(&pdev->dev, "unable to get clock\n");
ret = PTR_ERR(spi_imx->clk);
goto out_free_irq;
}
clk_enable(spi_imx->clk);
spi_imx->spi_clk = clk_get_rate(spi_imx->clk);
if (cpu_is_mx1() || cpu_is_mx21() || cpu_is_mx27())
writel(1, spi_imx->base + MXC_RESET);
/* drain receive buffer */
if (cpu_is_mx25() || cpu_is_mx31() || cpu_is_mx35())
while (readl(spi_imx->base + MX3_CSPISTAT) & MX3_CSPISTAT_RR)
readl(spi_imx->base + MXC_CSPIRXDATA);
spi_imx->intctrl(spi_imx, 0);
ret = spi_bitbang_start(&spi_imx->bitbang);
if (ret) {
dev_err(&pdev->dev, "bitbang start failed with %d\n", ret);
goto out_clk_put;
}
dev_info(&pdev->dev, "probed\n");
return ret;
out_clk_put:
clk_disable(spi_imx->clk);
clk_put(spi_imx->clk);
out_free_irq:
free_irq(spi_imx->irq, spi_imx);
out_iounmap:
iounmap(spi_imx->base);
out_release_mem:
release_mem_region(res->start, resource_size(res));
out_gpio_free:
for (i = 0; i < master->num_chipselect; i++)
if (spi_imx->chipselect[i] >= 0)
gpio_free(spi_imx->chipselect[i]);
out_master_put:
spi_master_put(master);
kfree(master);
platform_set_drvdata(pdev, NULL);
return ret;
}
static int __exit spi_imx_remove(struct platform_device *pdev)
{
struct spi_master *master = platform_get_drvdata(pdev);
struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
struct spi_imx_data *spi_imx = spi_master_get_devdata(master);
int i;
spi_bitbang_stop(&spi_imx->bitbang);
writel(0, spi_imx->base + MXC_CSPICTRL);
clk_disable(spi_imx->clk);
clk_put(spi_imx->clk);
free_irq(spi_imx->irq, spi_imx);
iounmap(spi_imx->base);
for (i = 0; i < master->num_chipselect; i++)
if (spi_imx->chipselect[i] >= 0)
gpio_free(spi_imx->chipselect[i]);
spi_master_put(master);
release_mem_region(res->start, resource_size(res));
platform_set_drvdata(pdev, NULL);
return 0;
}
static struct platform_driver spi_imx_driver = {
.driver = {
.name = DRIVER_NAME,
.owner = THIS_MODULE,
},
.probe = spi_imx_probe,
.remove = __exit_p(spi_imx_remove),
};
static int __init spi_imx_init(void)
{
return platform_driver_register(&spi_imx_driver);
}
static void __exit spi_imx_exit(void)
{
platform_driver_unregister(&spi_imx_driver);
}
module_init(spi_imx_init);
module_exit(spi_imx_exit);
MODULE_DESCRIPTION("SPI Master Controller driver");
MODULE_AUTHOR("Sascha Hauer, Pengutronix");
MODULE_LICENSE("GPL");