linux/drivers/spi/spi-imx.c
Lothar Waßmann 39ec0d3814 spi/imx: prevent NULL pointer dereference in spi_imx_probe()
When no platform_data is present and either 'spi-num-chipselects' is
not defined in the DT or 'cs-gpios' has less entries than
'spi-num-chipselects' specifies, the NULL platform_data pointer is
being dereferenced.

Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2012-04-10 22:17:15 -06:00

936 lines
24 KiB
C

/*
* 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/slab.h>
#include <linux/spi/spi.h>
#include <linux/spi/spi_bitbang.h>
#include <linux/types.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_gpio.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
/* 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;
u8 cs;
};
enum spi_imx_devtype {
IMX1_CSPI,
IMX21_CSPI,
IMX27_CSPI,
IMX31_CSPI,
IMX35_CSPI, /* CSPI on all i.mx except above */
IMX51_ECSPI, /* ECSPI on i.mx51 and later */
};
struct spi_imx_data;
struct spi_imx_devtype_data {
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 *);
void (*reset)(struct spi_imx_data *);
enum spi_imx_devtype devtype;
};
struct spi_imx_data {
struct spi_bitbang bitbang;
struct completion xfer_done;
void __iomem *base;
int irq;
struct clk *clk;
unsigned long spi_clk;
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 */
struct spi_imx_devtype_data *devtype_data;
int chipselect[0];
};
static inline int is_imx27_cspi(struct spi_imx_data *d)
{
return d->devtype_data->devtype == IMX27_CSPI;
}
static inline int is_imx35_cspi(struct spi_imx_data *d)
{
return d->devtype_data->devtype == IMX35_CSPI;
}
static inline unsigned spi_imx_get_fifosize(struct spi_imx_data *d)
{
return (d->devtype_data->devtype == IMX51_ECSPI) ? 64 : 8;
}
#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, unsigned int max)
{
int i;
for (i = 2; i < max; i++)
if (fspi * mxc_clkdivs[i] >= fin)
return i;
return max;
}
/* MX1, MX31, MX35, MX51 CSPI */
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 MX51_ECSPI_CTRL 0x08
#define MX51_ECSPI_CTRL_ENABLE (1 << 0)
#define MX51_ECSPI_CTRL_XCH (1 << 2)
#define MX51_ECSPI_CTRL_MODE_MASK (0xf << 4)
#define MX51_ECSPI_CTRL_POSTDIV_OFFSET 8
#define MX51_ECSPI_CTRL_PREDIV_OFFSET 12
#define MX51_ECSPI_CTRL_CS(cs) ((cs) << 18)
#define MX51_ECSPI_CTRL_BL_OFFSET 20
#define MX51_ECSPI_CONFIG 0x0c
#define MX51_ECSPI_CONFIG_SCLKPHA(cs) (1 << ((cs) + 0))
#define MX51_ECSPI_CONFIG_SCLKPOL(cs) (1 << ((cs) + 4))
#define MX51_ECSPI_CONFIG_SBBCTRL(cs) (1 << ((cs) + 8))
#define MX51_ECSPI_CONFIG_SSBPOL(cs) (1 << ((cs) + 12))
#define MX51_ECSPI_INT 0x10
#define MX51_ECSPI_INT_TEEN (1 << 0)
#define MX51_ECSPI_INT_RREN (1 << 3)
#define MX51_ECSPI_STAT 0x18
#define MX51_ECSPI_STAT_RR (1 << 3)
/* MX51 eCSPI */
static unsigned int mx51_ecspi_clkdiv(unsigned int fin, unsigned int fspi)
{
/*
* there are two 4-bit dividers, the pre-divider divides by
* $pre, the post-divider by 2^$post
*/
unsigned int pre, post;
if (unlikely(fspi > fin))
return 0;
post = fls(fin) - fls(fspi);
if (fin > fspi << post)
post++;
/* now we have: (fin <= fspi << post) with post being minimal */
post = max(4U, post) - 4;
if (unlikely(post > 0xf)) {
pr_err("%s: cannot set clock freq: %u (base freq: %u)\n",
__func__, fspi, fin);
return 0xff;
}
pre = DIV_ROUND_UP(fin, fspi << post) - 1;
pr_debug("%s: fin: %u, fspi: %u, post: %u, pre: %u\n",
__func__, fin, fspi, post, pre);
return (pre << MX51_ECSPI_CTRL_PREDIV_OFFSET) |
(post << MX51_ECSPI_CTRL_POSTDIV_OFFSET);
}
static void __maybe_unused mx51_ecspi_intctrl(struct spi_imx_data *spi_imx, int enable)
{
unsigned val = 0;
if (enable & MXC_INT_TE)
val |= MX51_ECSPI_INT_TEEN;
if (enable & MXC_INT_RR)
val |= MX51_ECSPI_INT_RREN;
writel(val, spi_imx->base + MX51_ECSPI_INT);
}
static void __maybe_unused mx51_ecspi_trigger(struct spi_imx_data *spi_imx)
{
u32 reg;
reg = readl(spi_imx->base + MX51_ECSPI_CTRL);
reg |= MX51_ECSPI_CTRL_XCH;
writel(reg, spi_imx->base + MX51_ECSPI_CTRL);
}
static int __maybe_unused mx51_ecspi_config(struct spi_imx_data *spi_imx,
struct spi_imx_config *config)
{
u32 ctrl = MX51_ECSPI_CTRL_ENABLE, cfg = 0;
/*
* The hardware seems to have a race condition when changing modes. The
* current assumption is that the selection of the channel arrives
* earlier in the hardware than the mode bits when they are written at
* the same time.
* So set master mode for all channels as we do not support slave mode.
*/
ctrl |= MX51_ECSPI_CTRL_MODE_MASK;
/* set clock speed */
ctrl |= mx51_ecspi_clkdiv(spi_imx->spi_clk, config->speed_hz);
/* set chip select to use */
ctrl |= MX51_ECSPI_CTRL_CS(config->cs);
ctrl |= (config->bpw - 1) << MX51_ECSPI_CTRL_BL_OFFSET;
cfg |= MX51_ECSPI_CONFIG_SBBCTRL(config->cs);
if (config->mode & SPI_CPHA)
cfg |= MX51_ECSPI_CONFIG_SCLKPHA(config->cs);
if (config->mode & SPI_CPOL)
cfg |= MX51_ECSPI_CONFIG_SCLKPOL(config->cs);
if (config->mode & SPI_CS_HIGH)
cfg |= MX51_ECSPI_CONFIG_SSBPOL(config->cs);
writel(ctrl, spi_imx->base + MX51_ECSPI_CTRL);
writel(cfg, spi_imx->base + MX51_ECSPI_CONFIG);
return 0;
}
static int __maybe_unused mx51_ecspi_rx_available(struct spi_imx_data *spi_imx)
{
return readl(spi_imx->base + MX51_ECSPI_STAT) & MX51_ECSPI_STAT_RR;
}
static void __maybe_unused mx51_ecspi_reset(struct spi_imx_data *spi_imx)
{
/* drain receive buffer */
while (mx51_ecspi_rx_available(spi_imx))
readl(spi_imx->base + MXC_CSPIRXDATA);
}
#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 __maybe_unused 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 __maybe_unused 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 __maybe_unused mx31_config(struct spi_imx_data *spi_imx,
struct spi_imx_config *config)
{
unsigned int reg = MX31_CSPICTRL_ENABLE | MX31_CSPICTRL_MASTER;
int cs = spi_imx->chipselect[config->cs];
reg |= spi_imx_clkdiv_2(spi_imx->spi_clk, config->speed_hz) <<
MX31_CSPICTRL_DR_SHIFT;
if (is_imx35_cspi(spi_imx)) {
reg |= (config->bpw - 1) << MX35_CSPICTRL_BL_SHIFT;
reg |= MX31_CSPICTRL_SSCTL;
} else {
reg |= (config->bpw - 1) << MX31_CSPICTRL_BC_SHIFT;
}
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 (cs < 0)
reg |= (cs + 32) <<
(is_imx35_cspi(spi_imx) ? MX35_CSPICTRL_CS_SHIFT :
MX31_CSPICTRL_CS_SHIFT);
writel(reg, spi_imx->base + MXC_CSPICTRL);
return 0;
}
static int __maybe_unused mx31_rx_available(struct spi_imx_data *spi_imx)
{
return readl(spi_imx->base + MX31_CSPISTATUS) & MX31_STATUS_RR;
}
static void __maybe_unused mx31_reset(struct spi_imx_data *spi_imx)
{
/* drain receive buffer */
while (readl(spi_imx->base + MX31_CSPISTATUS) & MX31_STATUS_RR)
readl(spi_imx->base + MXC_CSPIRXDATA);
}
#define MX21_INTREG_RR (1 << 4)
#define MX21_INTREG_TEEN (1 << 9)
#define MX21_INTREG_RREN (1 << 13)
#define MX21_CSPICTRL_POL (1 << 5)
#define MX21_CSPICTRL_PHA (1 << 6)
#define MX21_CSPICTRL_SSPOL (1 << 8)
#define MX21_CSPICTRL_XCH (1 << 9)
#define MX21_CSPICTRL_ENABLE (1 << 10)
#define MX21_CSPICTRL_MASTER (1 << 11)
#define MX21_CSPICTRL_DR_SHIFT 14
#define MX21_CSPICTRL_CS_SHIFT 19
static void __maybe_unused mx21_intctrl(struct spi_imx_data *spi_imx, int enable)
{
unsigned int val = 0;
if (enable & MXC_INT_TE)
val |= MX21_INTREG_TEEN;
if (enable & MXC_INT_RR)
val |= MX21_INTREG_RREN;
writel(val, spi_imx->base + MXC_CSPIINT);
}
static void __maybe_unused mx21_trigger(struct spi_imx_data *spi_imx)
{
unsigned int reg;
reg = readl(spi_imx->base + MXC_CSPICTRL);
reg |= MX21_CSPICTRL_XCH;
writel(reg, spi_imx->base + MXC_CSPICTRL);
}
static int __maybe_unused mx21_config(struct spi_imx_data *spi_imx,
struct spi_imx_config *config)
{
unsigned int reg = MX21_CSPICTRL_ENABLE | MX21_CSPICTRL_MASTER;
int cs = spi_imx->chipselect[config->cs];
unsigned int max = is_imx27_cspi(spi_imx) ? 16 : 18;
reg |= spi_imx_clkdiv_1(spi_imx->spi_clk, config->speed_hz, max) <<
MX21_CSPICTRL_DR_SHIFT;
reg |= config->bpw - 1;
if (config->mode & SPI_CPHA)
reg |= MX21_CSPICTRL_PHA;
if (config->mode & SPI_CPOL)
reg |= MX21_CSPICTRL_POL;
if (config->mode & SPI_CS_HIGH)
reg |= MX21_CSPICTRL_SSPOL;
if (cs < 0)
reg |= (cs + 32) << MX21_CSPICTRL_CS_SHIFT;
writel(reg, spi_imx->base + MXC_CSPICTRL);
return 0;
}
static int __maybe_unused mx21_rx_available(struct spi_imx_data *spi_imx)
{
return readl(spi_imx->base + MXC_CSPIINT) & MX21_INTREG_RR;
}
static void __maybe_unused mx21_reset(struct spi_imx_data *spi_imx)
{
writel(1, spi_imx->base + MXC_RESET);
}
#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 __maybe_unused 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 __maybe_unused 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 __maybe_unused 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 __maybe_unused mx1_rx_available(struct spi_imx_data *spi_imx)
{
return readl(spi_imx->base + MXC_CSPIINT) & MX1_INTREG_RR;
}
static void __maybe_unused mx1_reset(struct spi_imx_data *spi_imx)
{
writel(1, spi_imx->base + MXC_RESET);
}
static struct spi_imx_devtype_data imx1_cspi_devtype_data = {
.intctrl = mx1_intctrl,
.config = mx1_config,
.trigger = mx1_trigger,
.rx_available = mx1_rx_available,
.reset = mx1_reset,
.devtype = IMX1_CSPI,
};
static struct spi_imx_devtype_data imx21_cspi_devtype_data = {
.intctrl = mx21_intctrl,
.config = mx21_config,
.trigger = mx21_trigger,
.rx_available = mx21_rx_available,
.reset = mx21_reset,
.devtype = IMX21_CSPI,
};
static struct spi_imx_devtype_data imx27_cspi_devtype_data = {
/* i.mx27 cspi shares the functions with i.mx21 one */
.intctrl = mx21_intctrl,
.config = mx21_config,
.trigger = mx21_trigger,
.rx_available = mx21_rx_available,
.reset = mx21_reset,
.devtype = IMX27_CSPI,
};
static struct spi_imx_devtype_data imx31_cspi_devtype_data = {
.intctrl = mx31_intctrl,
.config = mx31_config,
.trigger = mx31_trigger,
.rx_available = mx31_rx_available,
.reset = mx31_reset,
.devtype = IMX31_CSPI,
};
static struct spi_imx_devtype_data imx35_cspi_devtype_data = {
/* i.mx35 and later cspi shares the functions with i.mx31 one */
.intctrl = mx31_intctrl,
.config = mx31_config,
.trigger = mx31_trigger,
.rx_available = mx31_rx_available,
.reset = mx31_reset,
.devtype = IMX35_CSPI,
};
static struct spi_imx_devtype_data imx51_ecspi_devtype_data = {
.intctrl = mx51_ecspi_intctrl,
.config = mx51_ecspi_config,
.trigger = mx51_ecspi_trigger,
.rx_available = mx51_ecspi_rx_available,
.reset = mx51_ecspi_reset,
.devtype = IMX51_ECSPI,
};
static struct platform_device_id spi_imx_devtype[] = {
{
.name = "imx1-cspi",
.driver_data = (kernel_ulong_t) &imx1_cspi_devtype_data,
}, {
.name = "imx21-cspi",
.driver_data = (kernel_ulong_t) &imx21_cspi_devtype_data,
}, {
.name = "imx27-cspi",
.driver_data = (kernel_ulong_t) &imx27_cspi_devtype_data,
}, {
.name = "imx31-cspi",
.driver_data = (kernel_ulong_t) &imx31_cspi_devtype_data,
}, {
.name = "imx35-cspi",
.driver_data = (kernel_ulong_t) &imx35_cspi_devtype_data,
}, {
.name = "imx51-ecspi",
.driver_data = (kernel_ulong_t) &imx51_ecspi_devtype_data,
}, {
/* sentinel */
}
};
static const struct of_device_id spi_imx_dt_ids[] = {
{ .compatible = "fsl,imx1-cspi", .data = &imx1_cspi_devtype_data, },
{ .compatible = "fsl,imx21-cspi", .data = &imx21_cspi_devtype_data, },
{ .compatible = "fsl,imx27-cspi", .data = &imx27_cspi_devtype_data, },
{ .compatible = "fsl,imx31-cspi", .data = &imx31_cspi_devtype_data, },
{ .compatible = "fsl,imx35-cspi", .data = &imx35_cspi_devtype_data, },
{ .compatible = "fsl,imx51-ecspi", .data = &imx51_ecspi_devtype_data, },
{ /* sentinel */ }
};
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 < spi_imx_get_fifosize(spi_imx)) {
if (!spi_imx->count)
break;
spi_imx->tx(spi_imx);
spi_imx->txfifo++;
}
spi_imx->devtype_data->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->devtype_data->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->devtype_data->intctrl(
spi_imx, MXC_INT_RR);
return IRQ_HANDLED;
}
spi_imx->devtype_data->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->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->devtype_data->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->devtype_data->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];
dev_dbg(&spi->dev, "%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 __devinit spi_imx_probe(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
const struct of_device_id *of_id =
of_match_device(spi_imx_dt_ids, &pdev->dev);
struct spi_imx_master *mxc_platform_info =
dev_get_platdata(&pdev->dev);
struct spi_master *master;
struct spi_imx_data *spi_imx;
struct resource *res;
int i, ret, num_cs;
if (!np && !mxc_platform_info) {
dev_err(&pdev->dev, "can't get the platform data\n");
return -EINVAL;
}
ret = of_property_read_u32(np, "fsl,spi-num-chipselects", &num_cs);
if (ret < 0) {
if (mxc_platform_info)
num_cs = mxc_platform_info->num_chipselect;
else
return ret;
}
master = spi_alloc_master(&pdev->dev,
sizeof(struct spi_imx_data) + sizeof(int) * num_cs);
if (!master)
return -ENOMEM;
platform_set_drvdata(pdev, master);
master->bus_num = pdev->id;
master->num_chipselect = num_cs;
spi_imx = spi_master_get_devdata(master);
spi_imx->bitbang.master = spi_master_get(master);
for (i = 0; i < master->num_chipselect; i++) {
int cs_gpio = of_get_named_gpio(np, "cs-gpios", i);
if (cs_gpio < 0 && mxc_platform_info)
cs_gpio = mxc_platform_info->chipselect[i];
spi_imx->chipselect[i] = cs_gpio;
if (cs_gpio < 0)
continue;
ret = gpio_request(spi_imx->chipselect[i], DRIVER_NAME);
if (ret) {
dev_err(&pdev->dev, "can't get cs gpios\n");
goto out_gpio_free;
}
}
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);
spi_imx->devtype_data = of_id ? of_id->data :
(struct spi_imx_devtype_data *) pdev->id_entry->driver_data;
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;
}
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);
spi_imx->devtype_data->reset(spi_imx);
spi_imx->devtype_data->intctrl(spi_imx, 0);
master->dev.of_node = pdev->dev.of_node;
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:
while (--i >= 0) {
if (spi_imx->chipselect[i] >= 0)
gpio_free(spi_imx->chipselect[i]);
}
spi_master_put(master);
kfree(master);
platform_set_drvdata(pdev, NULL);
return ret;
}
static int __devexit 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,
.of_match_table = spi_imx_dt_ids,
},
.id_table = spi_imx_devtype,
.probe = spi_imx_probe,
.remove = __devexit_p(spi_imx_remove),
};
module_platform_driver(spi_imx_driver);
MODULE_DESCRIPTION("SPI Master Controller driver");
MODULE_AUTHOR("Sascha Hauer, Pengutronix");
MODULE_LICENSE("GPL");