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linux/drivers/spi/omap2_mcspi.c

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/*
* OMAP2 McSPI controller driver
*
* Copyright (C) 2005, 2006 Nokia Corporation
* Author: Samuel Ortiz <samuel.ortiz@nokia.com> and
* Juha Yrjölä <juha.yrjola@nokia.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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/platform_device.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/spi/spi.h>
#include <mach/dma.h>
#include <mach/clock.h>
#define OMAP2_MCSPI_MAX_FREQ 48000000
#define OMAP2_MCSPI_REVISION 0x00
#define OMAP2_MCSPI_SYSCONFIG 0x10
#define OMAP2_MCSPI_SYSSTATUS 0x14
#define OMAP2_MCSPI_IRQSTATUS 0x18
#define OMAP2_MCSPI_IRQENABLE 0x1c
#define OMAP2_MCSPI_WAKEUPENABLE 0x20
#define OMAP2_MCSPI_SYST 0x24
#define OMAP2_MCSPI_MODULCTRL 0x28
/* per-channel banks, 0x14 bytes each, first is: */
#define OMAP2_MCSPI_CHCONF0 0x2c
#define OMAP2_MCSPI_CHSTAT0 0x30
#define OMAP2_MCSPI_CHCTRL0 0x34
#define OMAP2_MCSPI_TX0 0x38
#define OMAP2_MCSPI_RX0 0x3c
/* per-register bitmasks: */
#define OMAP2_MCSPI_SYSCONFIG_SMARTIDLE (2 << 3)
#define OMAP2_MCSPI_SYSCONFIG_ENAWAKEUP (1 << 2)
#define OMAP2_MCSPI_SYSCONFIG_AUTOIDLE (1 << 0)
#define OMAP2_MCSPI_SYSCONFIG_SOFTRESET (1 << 1)
#define OMAP2_MCSPI_SYSSTATUS_RESETDONE (1 << 0)
#define OMAP2_MCSPI_MODULCTRL_SINGLE (1 << 0)
#define OMAP2_MCSPI_MODULCTRL_MS (1 << 2)
#define OMAP2_MCSPI_MODULCTRL_STEST (1 << 3)
#define OMAP2_MCSPI_CHCONF_PHA (1 << 0)
#define OMAP2_MCSPI_CHCONF_POL (1 << 1)
#define OMAP2_MCSPI_CHCONF_CLKD_MASK (0x0f << 2)
#define OMAP2_MCSPI_CHCONF_EPOL (1 << 6)
#define OMAP2_MCSPI_CHCONF_WL_MASK (0x1f << 7)
#define OMAP2_MCSPI_CHCONF_TRM_RX_ONLY (0x01 << 12)
#define OMAP2_MCSPI_CHCONF_TRM_TX_ONLY (0x02 << 12)
#define OMAP2_MCSPI_CHCONF_TRM_MASK (0x03 << 12)
#define OMAP2_MCSPI_CHCONF_DMAW (1 << 14)
#define OMAP2_MCSPI_CHCONF_DMAR (1 << 15)
#define OMAP2_MCSPI_CHCONF_DPE0 (1 << 16)
#define OMAP2_MCSPI_CHCONF_DPE1 (1 << 17)
#define OMAP2_MCSPI_CHCONF_IS (1 << 18)
#define OMAP2_MCSPI_CHCONF_TURBO (1 << 19)
#define OMAP2_MCSPI_CHCONF_FORCE (1 << 20)
#define OMAP2_MCSPI_CHSTAT_RXS (1 << 0)
#define OMAP2_MCSPI_CHSTAT_TXS (1 << 1)
#define OMAP2_MCSPI_CHSTAT_EOT (1 << 2)
#define OMAP2_MCSPI_CHCTRL_EN (1 << 0)
#define OMAP2_MCSPI_WAKEUPENABLE_WKEN (1 << 0)
/* We have 2 DMA channels per CS, one for RX and one for TX */
struct omap2_mcspi_dma {
int dma_tx_channel;
int dma_rx_channel;
int dma_tx_sync_dev;
int dma_rx_sync_dev;
struct completion dma_tx_completion;
struct completion dma_rx_completion;
};
/* use PIO for small transfers, avoiding DMA setup/teardown overhead and
* cache operations; better heuristics consider wordsize and bitrate.
*/
#define DMA_MIN_BYTES 8
struct omap2_mcspi {
struct work_struct work;
/* lock protects queue and registers */
spinlock_t lock;
struct list_head msg_queue;
struct spi_master *master;
struct clk *ick;
struct clk *fck;
/* Virtual base address of the controller */
void __iomem *base;
unsigned long phys;
/* SPI1 has 4 channels, while SPI2 has 2 */
struct omap2_mcspi_dma *dma_channels;
};
struct omap2_mcspi_cs {
void __iomem *base;
unsigned long phys;
int word_len;
};
static struct workqueue_struct *omap2_mcspi_wq;
#define MOD_REG_BIT(val, mask, set) do { \
if (set) \
val |= mask; \
else \
val &= ~mask; \
} while (0)
static inline void mcspi_write_reg(struct spi_master *master,
int idx, u32 val)
{
struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
__raw_writel(val, mcspi->base + idx);
}
static inline u32 mcspi_read_reg(struct spi_master *master, int idx)
{
struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
return __raw_readl(mcspi->base + idx);
}
static inline void mcspi_write_cs_reg(const struct spi_device *spi,
int idx, u32 val)
{
struct omap2_mcspi_cs *cs = spi->controller_state;
__raw_writel(val, cs->base + idx);
}
static inline u32 mcspi_read_cs_reg(const struct spi_device *spi, int idx)
{
struct omap2_mcspi_cs *cs = spi->controller_state;
return __raw_readl(cs->base + idx);
}
static void omap2_mcspi_set_dma_req(const struct spi_device *spi,
int is_read, int enable)
{
u32 l, rw;
l = mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
if (is_read) /* 1 is read, 0 write */
rw = OMAP2_MCSPI_CHCONF_DMAR;
else
rw = OMAP2_MCSPI_CHCONF_DMAW;
MOD_REG_BIT(l, rw, enable);
mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, l);
}
static void omap2_mcspi_set_enable(const struct spi_device *spi, int enable)
{
u32 l;
l = enable ? OMAP2_MCSPI_CHCTRL_EN : 0;
mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, l);
}
static void omap2_mcspi_force_cs(struct spi_device *spi, int cs_active)
{
u32 l;
l = mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
MOD_REG_BIT(l, OMAP2_MCSPI_CHCONF_FORCE, cs_active);
mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, l);
}
static void omap2_mcspi_set_master_mode(struct spi_master *master)
{
u32 l;
/* setup when switching from (reset default) slave mode
* to single-channel master mode
*/
l = mcspi_read_reg(master, OMAP2_MCSPI_MODULCTRL);
MOD_REG_BIT(l, OMAP2_MCSPI_MODULCTRL_STEST, 0);
MOD_REG_BIT(l, OMAP2_MCSPI_MODULCTRL_MS, 0);
MOD_REG_BIT(l, OMAP2_MCSPI_MODULCTRL_SINGLE, 1);
mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, l);
}
static unsigned
omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
{
struct omap2_mcspi *mcspi;
struct omap2_mcspi_cs *cs = spi->controller_state;
struct omap2_mcspi_dma *mcspi_dma;
unsigned int count, c;
unsigned long base, tx_reg, rx_reg;
int word_len, data_type, element_count;
u8 * rx;
const u8 * tx;
mcspi = spi_master_get_devdata(spi->master);
mcspi_dma = &mcspi->dma_channels[spi->chip_select];
count = xfer->len;
c = count;
word_len = cs->word_len;
base = cs->phys;
tx_reg = base + OMAP2_MCSPI_TX0;
rx_reg = base + OMAP2_MCSPI_RX0;
rx = xfer->rx_buf;
tx = xfer->tx_buf;
if (word_len <= 8) {
data_type = OMAP_DMA_DATA_TYPE_S8;
element_count = count;
} else if (word_len <= 16) {
data_type = OMAP_DMA_DATA_TYPE_S16;
element_count = count >> 1;
} else /* word_len <= 32 */ {
data_type = OMAP_DMA_DATA_TYPE_S32;
element_count = count >> 2;
}
if (tx != NULL) {
omap_set_dma_transfer_params(mcspi_dma->dma_tx_channel,
data_type, element_count, 1,
OMAP_DMA_SYNC_ELEMENT,
mcspi_dma->dma_tx_sync_dev, 0);
omap_set_dma_dest_params(mcspi_dma->dma_tx_channel, 0,
OMAP_DMA_AMODE_CONSTANT,
tx_reg, 0, 0);
omap_set_dma_src_params(mcspi_dma->dma_tx_channel, 0,
OMAP_DMA_AMODE_POST_INC,
xfer->tx_dma, 0, 0);
}
if (rx != NULL) {
omap_set_dma_transfer_params(mcspi_dma->dma_rx_channel,
data_type, element_count - 1, 1,
OMAP_DMA_SYNC_ELEMENT,
mcspi_dma->dma_rx_sync_dev, 1);
omap_set_dma_src_params(mcspi_dma->dma_rx_channel, 0,
OMAP_DMA_AMODE_CONSTANT,
rx_reg, 0, 0);
omap_set_dma_dest_params(mcspi_dma->dma_rx_channel, 0,
OMAP_DMA_AMODE_POST_INC,
xfer->rx_dma, 0, 0);
}
if (tx != NULL) {
omap_start_dma(mcspi_dma->dma_tx_channel);
omap2_mcspi_set_dma_req(spi, 0, 1);
}
if (rx != NULL) {
omap_start_dma(mcspi_dma->dma_rx_channel);
omap2_mcspi_set_dma_req(spi, 1, 1);
}
if (tx != NULL) {
wait_for_completion(&mcspi_dma->dma_tx_completion);
dma_unmap_single(NULL, xfer->tx_dma, count, DMA_TO_DEVICE);
}
if (rx != NULL) {
wait_for_completion(&mcspi_dma->dma_rx_completion);
dma_unmap_single(NULL, xfer->rx_dma, count, DMA_FROM_DEVICE);
omap2_mcspi_set_enable(spi, 0);
if (likely(mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHSTAT0)
& OMAP2_MCSPI_CHSTAT_RXS)) {
u32 w;
w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
if (word_len <= 8)
((u8 *)xfer->rx_buf)[element_count - 1] = w;
else if (word_len <= 16)
((u16 *)xfer->rx_buf)[element_count - 1] = w;
else /* word_len <= 32 */
((u32 *)xfer->rx_buf)[element_count - 1] = w;
} else {
dev_err(&spi->dev, "DMA RX last word empty");
count -= (word_len <= 8) ? 1 :
(word_len <= 16) ? 2 :
/* word_len <= 32 */ 4;
}
omap2_mcspi_set_enable(spi, 1);
}
return count;
}
static int mcspi_wait_for_reg_bit(void __iomem *reg, unsigned long bit)
{
unsigned long timeout;
timeout = jiffies + msecs_to_jiffies(1000);
while (!(__raw_readl(reg) & bit)) {
if (time_after(jiffies, timeout))
return -1;
cpu_relax();
}
return 0;
}
static unsigned
omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer)
{
struct omap2_mcspi *mcspi;
struct omap2_mcspi_cs *cs = spi->controller_state;
unsigned int count, c;
u32 l;
void __iomem *base = cs->base;
void __iomem *tx_reg;
void __iomem *rx_reg;
void __iomem *chstat_reg;
int word_len;
mcspi = spi_master_get_devdata(spi->master);
count = xfer->len;
c = count;
word_len = cs->word_len;
l = mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
l &= ~OMAP2_MCSPI_CHCONF_TRM_MASK;
/* We store the pre-calculated register addresses on stack to speed
* up the transfer loop. */
tx_reg = base + OMAP2_MCSPI_TX0;
rx_reg = base + OMAP2_MCSPI_RX0;
chstat_reg = base + OMAP2_MCSPI_CHSTAT0;
if (word_len <= 8) {
u8 *rx;
const u8 *tx;
rx = xfer->rx_buf;
tx = xfer->tx_buf;
do {
c -= 1;
if (tx != NULL) {
if (mcspi_wait_for_reg_bit(chstat_reg,
OMAP2_MCSPI_CHSTAT_TXS) < 0) {
dev_err(&spi->dev, "TXS timed out\n");
goto out;
}
#ifdef VERBOSE
dev_dbg(&spi->dev, "write-%d %02x\n",
word_len, *tx);
#endif
__raw_writel(*tx++, tx_reg);
}
if (rx != NULL) {
if (mcspi_wait_for_reg_bit(chstat_reg,
OMAP2_MCSPI_CHSTAT_RXS) < 0) {
dev_err(&spi->dev, "RXS timed out\n");
goto out;
}
/* prevent last RX_ONLY read from triggering
* more word i/o: switch to rx+tx
*/
if (c == 0 && tx == NULL)
mcspi_write_cs_reg(spi,
OMAP2_MCSPI_CHCONF0, l);
*rx++ = __raw_readl(rx_reg);
#ifdef VERBOSE
dev_dbg(&spi->dev, "read-%d %02x\n",
word_len, *(rx - 1));
#endif
}
} while (c);
} else if (word_len <= 16) {
u16 *rx;
const u16 *tx;
rx = xfer->rx_buf;
tx = xfer->tx_buf;
do {
c -= 2;
if (tx != NULL) {
if (mcspi_wait_for_reg_bit(chstat_reg,
OMAP2_MCSPI_CHSTAT_TXS) < 0) {
dev_err(&spi->dev, "TXS timed out\n");
goto out;
}
#ifdef VERBOSE
dev_dbg(&spi->dev, "write-%d %04x\n",
word_len, *tx);
#endif
__raw_writel(*tx++, tx_reg);
}
if (rx != NULL) {
if (mcspi_wait_for_reg_bit(chstat_reg,
OMAP2_MCSPI_CHSTAT_RXS) < 0) {
dev_err(&spi->dev, "RXS timed out\n");
goto out;
}
/* prevent last RX_ONLY read from triggering
* more word i/o: switch to rx+tx
*/
if (c == 0 && tx == NULL)
mcspi_write_cs_reg(spi,
OMAP2_MCSPI_CHCONF0, l);
*rx++ = __raw_readl(rx_reg);
#ifdef VERBOSE
dev_dbg(&spi->dev, "read-%d %04x\n",
word_len, *(rx - 1));
#endif
}
} while (c);
} else if (word_len <= 32) {
u32 *rx;
const u32 *tx;
rx = xfer->rx_buf;
tx = xfer->tx_buf;
do {
c -= 4;
if (tx != NULL) {
if (mcspi_wait_for_reg_bit(chstat_reg,
OMAP2_MCSPI_CHSTAT_TXS) < 0) {
dev_err(&spi->dev, "TXS timed out\n");
goto out;
}
#ifdef VERBOSE
dev_dbg(&spi->dev, "write-%d %04x\n",
word_len, *tx);
#endif
__raw_writel(*tx++, tx_reg);
}
if (rx != NULL) {
if (mcspi_wait_for_reg_bit(chstat_reg,
OMAP2_MCSPI_CHSTAT_RXS) < 0) {
dev_err(&spi->dev, "RXS timed out\n");
goto out;
}
/* prevent last RX_ONLY read from triggering
* more word i/o: switch to rx+tx
*/
if (c == 0 && tx == NULL)
mcspi_write_cs_reg(spi,
OMAP2_MCSPI_CHCONF0, l);
*rx++ = __raw_readl(rx_reg);
#ifdef VERBOSE
dev_dbg(&spi->dev, "read-%d %04x\n",
word_len, *(rx - 1));
#endif
}
} while (c);
}
/* for TX_ONLY mode, be sure all words have shifted out */
if (xfer->rx_buf == NULL) {
if (mcspi_wait_for_reg_bit(chstat_reg,
OMAP2_MCSPI_CHSTAT_TXS) < 0) {
dev_err(&spi->dev, "TXS timed out\n");
} else if (mcspi_wait_for_reg_bit(chstat_reg,
OMAP2_MCSPI_CHSTAT_EOT) < 0)
dev_err(&spi->dev, "EOT timed out\n");
}
out:
return count - c;
}
/* called only when no transfer is active to this device */
static int omap2_mcspi_setup_transfer(struct spi_device *spi,
struct spi_transfer *t)
{
struct omap2_mcspi_cs *cs = spi->controller_state;
struct omap2_mcspi *mcspi;
u32 l = 0, div = 0;
u8 word_len = spi->bits_per_word;
mcspi = spi_master_get_devdata(spi->master);
if (t != NULL && t->bits_per_word)
word_len = t->bits_per_word;
cs->word_len = word_len;
if (spi->max_speed_hz) {
while (div <= 15 && (OMAP2_MCSPI_MAX_FREQ / (1 << div))
> spi->max_speed_hz)
div++;
} else
div = 15;
l = mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
/* standard 4-wire master mode: SCK, MOSI/out, MISO/in, nCS
* REVISIT: this controller could support SPI_3WIRE mode.
*/
l &= ~(OMAP2_MCSPI_CHCONF_IS|OMAP2_MCSPI_CHCONF_DPE1);
l |= OMAP2_MCSPI_CHCONF_DPE0;
/* wordlength */
l &= ~OMAP2_MCSPI_CHCONF_WL_MASK;
l |= (word_len - 1) << 7;
/* set chipselect polarity; manage with FORCE */
if (!(spi->mode & SPI_CS_HIGH))
l |= OMAP2_MCSPI_CHCONF_EPOL; /* active-low; normal */
else
l &= ~OMAP2_MCSPI_CHCONF_EPOL;
/* set clock divisor */
l &= ~OMAP2_MCSPI_CHCONF_CLKD_MASK;
l |= div << 2;
/* set SPI mode 0..3 */
if (spi->mode & SPI_CPOL)
l |= OMAP2_MCSPI_CHCONF_POL;
else
l &= ~OMAP2_MCSPI_CHCONF_POL;
if (spi->mode & SPI_CPHA)
l |= OMAP2_MCSPI_CHCONF_PHA;
else
l &= ~OMAP2_MCSPI_CHCONF_PHA;
mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, l);
dev_dbg(&spi->dev, "setup: speed %d, sample %s edge, clk %s\n",
OMAP2_MCSPI_MAX_FREQ / (1 << div),
(spi->mode & SPI_CPHA) ? "trailing" : "leading",
(spi->mode & SPI_CPOL) ? "inverted" : "normal");
return 0;
}
static void omap2_mcspi_dma_rx_callback(int lch, u16 ch_status, void *data)
{
struct spi_device *spi = data;
struct omap2_mcspi *mcspi;
struct omap2_mcspi_dma *mcspi_dma;
mcspi = spi_master_get_devdata(spi->master);
mcspi_dma = &(mcspi->dma_channels[spi->chip_select]);
complete(&mcspi_dma->dma_rx_completion);
/* We must disable the DMA RX request */
omap2_mcspi_set_dma_req(spi, 1, 0);
}
static void omap2_mcspi_dma_tx_callback(int lch, u16 ch_status, void *data)
{
struct spi_device *spi = data;
struct omap2_mcspi *mcspi;
struct omap2_mcspi_dma *mcspi_dma;
mcspi = spi_master_get_devdata(spi->master);
mcspi_dma = &(mcspi->dma_channels[spi->chip_select]);
complete(&mcspi_dma->dma_tx_completion);
/* We must disable the DMA TX request */
omap2_mcspi_set_dma_req(spi, 0, 0);
}
static int omap2_mcspi_request_dma(struct spi_device *spi)
{
struct spi_master *master = spi->master;
struct omap2_mcspi *mcspi;
struct omap2_mcspi_dma *mcspi_dma;
mcspi = spi_master_get_devdata(master);
mcspi_dma = mcspi->dma_channels + spi->chip_select;
if (omap_request_dma(mcspi_dma->dma_rx_sync_dev, "McSPI RX",
omap2_mcspi_dma_rx_callback, spi,
&mcspi_dma->dma_rx_channel)) {
dev_err(&spi->dev, "no RX DMA channel for McSPI\n");
return -EAGAIN;
}
if (omap_request_dma(mcspi_dma->dma_tx_sync_dev, "McSPI TX",
omap2_mcspi_dma_tx_callback, spi,
&mcspi_dma->dma_tx_channel)) {
omap_free_dma(mcspi_dma->dma_rx_channel);
mcspi_dma->dma_rx_channel = -1;
dev_err(&spi->dev, "no TX DMA channel for McSPI\n");
return -EAGAIN;
}
init_completion(&mcspi_dma->dma_rx_completion);
init_completion(&mcspi_dma->dma_tx_completion);
return 0;
}
static int omap2_mcspi_setup(struct spi_device *spi)
{
int ret;
struct omap2_mcspi *mcspi;
struct omap2_mcspi_dma *mcspi_dma;
struct omap2_mcspi_cs *cs = spi->controller_state;
if (spi->bits_per_word < 4 || spi->bits_per_word > 32) {
dev_dbg(&spi->dev, "setup: unsupported %d bit words\n",
spi->bits_per_word);
return -EINVAL;
}
mcspi = spi_master_get_devdata(spi->master);
mcspi_dma = &mcspi->dma_channels[spi->chip_select];
if (!cs) {
cs = kzalloc(sizeof *cs, GFP_KERNEL);
if (!cs)
return -ENOMEM;
cs->base = mcspi->base + spi->chip_select * 0x14;
cs->phys = mcspi->phys + spi->chip_select * 0x14;
spi->controller_state = cs;
}
if (mcspi_dma->dma_rx_channel == -1
|| mcspi_dma->dma_tx_channel == -1) {
ret = omap2_mcspi_request_dma(spi);
if (ret < 0)
return ret;
}
clk_enable(mcspi->ick);
clk_enable(mcspi->fck);
ret = omap2_mcspi_setup_transfer(spi, NULL);
clk_disable(mcspi->fck);
clk_disable(mcspi->ick);
return ret;
}
static void omap2_mcspi_cleanup(struct spi_device *spi)
{
struct omap2_mcspi *mcspi;
struct omap2_mcspi_dma *mcspi_dma;
mcspi = spi_master_get_devdata(spi->master);
mcspi_dma = &mcspi->dma_channels[spi->chip_select];
kfree(spi->controller_state);
if (mcspi_dma->dma_rx_channel != -1) {
omap_free_dma(mcspi_dma->dma_rx_channel);
mcspi_dma->dma_rx_channel = -1;
}
if (mcspi_dma->dma_tx_channel != -1) {
omap_free_dma(mcspi_dma->dma_tx_channel);
mcspi_dma->dma_tx_channel = -1;
}
}
static void omap2_mcspi_work(struct work_struct *work)
{
struct omap2_mcspi *mcspi;
mcspi = container_of(work, struct omap2_mcspi, work);
spin_lock_irq(&mcspi->lock);
clk_enable(mcspi->ick);
clk_enable(mcspi->fck);
/* We only enable one channel at a time -- the one whose message is
* at the head of the queue -- although this controller would gladly
* arbitrate among multiple channels. This corresponds to "single
* channel" master mode. As a side effect, we need to manage the
* chipselect with the FORCE bit ... CS != channel enable.
*/
while (!list_empty(&mcspi->msg_queue)) {
struct spi_message *m;
struct spi_device *spi;
struct spi_transfer *t = NULL;
int cs_active = 0;
struct omap2_mcspi_cs *cs;
int par_override = 0;
int status = 0;
u32 chconf;
m = container_of(mcspi->msg_queue.next, struct spi_message,
queue);
list_del_init(&m->queue);
spin_unlock_irq(&mcspi->lock);
spi = m->spi;
cs = spi->controller_state;
omap2_mcspi_set_enable(spi, 1);
list_for_each_entry(t, &m->transfers, transfer_list) {
if (t->tx_buf == NULL && t->rx_buf == NULL && t->len) {
status = -EINVAL;
break;
}
if (par_override || t->speed_hz || t->bits_per_word) {
par_override = 1;
status = omap2_mcspi_setup_transfer(spi, t);
if (status < 0)
break;
if (!t->speed_hz && !t->bits_per_word)
par_override = 0;
}
if (!cs_active) {
omap2_mcspi_force_cs(spi, 1);
cs_active = 1;
}
chconf = mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
chconf &= ~OMAP2_MCSPI_CHCONF_TRM_MASK;
if (t->tx_buf == NULL)
chconf |= OMAP2_MCSPI_CHCONF_TRM_RX_ONLY;
else if (t->rx_buf == NULL)
chconf |= OMAP2_MCSPI_CHCONF_TRM_TX_ONLY;
mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, chconf);
if (t->len) {
unsigned count;
/* RX_ONLY mode needs dummy data in TX reg */
if (t->tx_buf == NULL)
__raw_writel(0, cs->base
+ OMAP2_MCSPI_TX0);
if (m->is_dma_mapped || t->len >= DMA_MIN_BYTES)
count = omap2_mcspi_txrx_dma(spi, t);
else
count = omap2_mcspi_txrx_pio(spi, t);
m->actual_length += count;
if (count != t->len) {
status = -EIO;
break;
}
}
if (t->delay_usecs)
udelay(t->delay_usecs);
/* ignore the "leave it on after last xfer" hint */
if (t->cs_change) {
omap2_mcspi_force_cs(spi, 0);
cs_active = 0;
}
}
/* Restore defaults if they were overriden */
if (par_override) {
par_override = 0;
status = omap2_mcspi_setup_transfer(spi, NULL);
}
if (cs_active)
omap2_mcspi_force_cs(spi, 0);
omap2_mcspi_set_enable(spi, 0);
m->status = status;
m->complete(m->context);
spin_lock_irq(&mcspi->lock);
}
clk_disable(mcspi->fck);
clk_disable(mcspi->ick);
spin_unlock_irq(&mcspi->lock);
}
static int omap2_mcspi_transfer(struct spi_device *spi, struct spi_message *m)
{
struct omap2_mcspi *mcspi;
unsigned long flags;
struct spi_transfer *t;
m->actual_length = 0;
m->status = 0;
/* reject invalid messages and transfers */
if (list_empty(&m->transfers) || !m->complete)
return -EINVAL;
list_for_each_entry(t, &m->transfers, transfer_list) {
const void *tx_buf = t->tx_buf;
void *rx_buf = t->rx_buf;
unsigned len = t->len;
if (t->speed_hz > OMAP2_MCSPI_MAX_FREQ
|| (len && !(rx_buf || tx_buf))
|| (t->bits_per_word &&
( t->bits_per_word < 4
|| t->bits_per_word > 32))) {
dev_dbg(&spi->dev, "transfer: %d Hz, %d %s%s, %d bpw\n",
t->speed_hz,
len,
tx_buf ? "tx" : "",
rx_buf ? "rx" : "",
t->bits_per_word);
return -EINVAL;
}
if (t->speed_hz && t->speed_hz < OMAP2_MCSPI_MAX_FREQ/(1<<16)) {
dev_dbg(&spi->dev, "%d Hz max exceeds %d\n",
t->speed_hz,
OMAP2_MCSPI_MAX_FREQ/(1<<16));
return -EINVAL;
}
if (m->is_dma_mapped || len < DMA_MIN_BYTES)
continue;
/* Do DMA mapping "early" for better error reporting and
* dcache use. Note that if dma_unmap_single() ever starts
* to do real work on ARM, we'd need to clean up mappings
* for previous transfers on *ALL* exits of this loop...
*/
if (tx_buf != NULL) {
t->tx_dma = dma_map_single(&spi->dev, (void *) tx_buf,
len, DMA_TO_DEVICE);
if (dma_mapping_error(&spi->dev, t->tx_dma)) {
dev_dbg(&spi->dev, "dma %cX %d bytes error\n",
'T', len);
return -EINVAL;
}
}
if (rx_buf != NULL) {
t->rx_dma = dma_map_single(&spi->dev, rx_buf, t->len,
DMA_FROM_DEVICE);
if (dma_mapping_error(&spi->dev, t->rx_dma)) {
dev_dbg(&spi->dev, "dma %cX %d bytes error\n",
'R', len);
if (tx_buf != NULL)
dma_unmap_single(NULL, t->tx_dma,
len, DMA_TO_DEVICE);
return -EINVAL;
}
}
}
mcspi = spi_master_get_devdata(spi->master);
spin_lock_irqsave(&mcspi->lock, flags);
list_add_tail(&m->queue, &mcspi->msg_queue);
queue_work(omap2_mcspi_wq, &mcspi->work);
spin_unlock_irqrestore(&mcspi->lock, flags);
return 0;
}
static int __init omap2_mcspi_reset(struct omap2_mcspi *mcspi)
{
struct spi_master *master = mcspi->master;
u32 tmp;
clk_enable(mcspi->ick);
clk_enable(mcspi->fck);
mcspi_write_reg(master, OMAP2_MCSPI_SYSCONFIG,
OMAP2_MCSPI_SYSCONFIG_SOFTRESET);
do {
tmp = mcspi_read_reg(master, OMAP2_MCSPI_SYSSTATUS);
} while (!(tmp & OMAP2_MCSPI_SYSSTATUS_RESETDONE));
mcspi_write_reg(master, OMAP2_MCSPI_SYSCONFIG,
OMAP2_MCSPI_SYSCONFIG_AUTOIDLE |
OMAP2_MCSPI_SYSCONFIG_ENAWAKEUP |
OMAP2_MCSPI_SYSCONFIG_SMARTIDLE);
mcspi_write_reg(master, OMAP2_MCSPI_WAKEUPENABLE,
OMAP2_MCSPI_WAKEUPENABLE_WKEN);
omap2_mcspi_set_master_mode(master);
clk_disable(mcspi->fck);
clk_disable(mcspi->ick);
return 0;
}
static u8 __initdata spi1_rxdma_id [] = {
OMAP24XX_DMA_SPI1_RX0,
OMAP24XX_DMA_SPI1_RX1,
OMAP24XX_DMA_SPI1_RX2,
OMAP24XX_DMA_SPI1_RX3,
};
static u8 __initdata spi1_txdma_id [] = {
OMAP24XX_DMA_SPI1_TX0,
OMAP24XX_DMA_SPI1_TX1,
OMAP24XX_DMA_SPI1_TX2,
OMAP24XX_DMA_SPI1_TX3,
};
static u8 __initdata spi2_rxdma_id[] = {
OMAP24XX_DMA_SPI2_RX0,
OMAP24XX_DMA_SPI2_RX1,
};
static u8 __initdata spi2_txdma_id[] = {
OMAP24XX_DMA_SPI2_TX0,
OMAP24XX_DMA_SPI2_TX1,
};
#if defined(CONFIG_ARCH_OMAP2430) || defined(CONFIG_ARCH_OMAP34XX)
static u8 __initdata spi3_rxdma_id[] = {
OMAP24XX_DMA_SPI3_RX0,
OMAP24XX_DMA_SPI3_RX1,
};
static u8 __initdata spi3_txdma_id[] = {
OMAP24XX_DMA_SPI3_TX0,
OMAP24XX_DMA_SPI3_TX1,
};
#endif
#ifdef CONFIG_ARCH_OMAP3
static u8 __initdata spi4_rxdma_id[] = {
OMAP34XX_DMA_SPI4_RX0,
};
static u8 __initdata spi4_txdma_id[] = {
OMAP34XX_DMA_SPI4_TX0,
};
#endif
static int __init omap2_mcspi_probe(struct platform_device *pdev)
{
struct spi_master *master;
struct omap2_mcspi *mcspi;
struct resource *r;
int status = 0, i;
const u8 *rxdma_id, *txdma_id;
unsigned num_chipselect;
switch (pdev->id) {
case 1:
rxdma_id = spi1_rxdma_id;
txdma_id = spi1_txdma_id;
num_chipselect = 4;
break;
case 2:
rxdma_id = spi2_rxdma_id;
txdma_id = spi2_txdma_id;
num_chipselect = 2;
break;
#if defined(CONFIG_ARCH_OMAP2430) || defined(CONFIG_ARCH_OMAP3)
case 3:
rxdma_id = spi3_rxdma_id;
txdma_id = spi3_txdma_id;
num_chipselect = 2;
break;
#endif
#ifdef CONFIG_ARCH_OMAP3
case 4:
rxdma_id = spi4_rxdma_id;
txdma_id = spi4_txdma_id;
num_chipselect = 1;
break;
#endif
default:
return -EINVAL;
}
master = spi_alloc_master(&pdev->dev, sizeof *mcspi);
if (master == NULL) {
dev_dbg(&pdev->dev, "master allocation failed\n");
return -ENOMEM;
}
/* the spi->mode bits understood by this driver: */
master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
if (pdev->id != -1)
master->bus_num = pdev->id;
master->setup = omap2_mcspi_setup;
master->transfer = omap2_mcspi_transfer;
master->cleanup = omap2_mcspi_cleanup;
master->num_chipselect = num_chipselect;
dev_set_drvdata(&pdev->dev, master);
mcspi = spi_master_get_devdata(master);
mcspi->master = master;
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (r == NULL) {
status = -ENODEV;
goto err1;
}
if (!request_mem_region(r->start, (r->end - r->start) + 1,
dev_name(&pdev->dev))) {
status = -EBUSY;
goto err1;
}
mcspi->phys = r->start;
mcspi->base = ioremap(r->start, r->end - r->start + 1);
if (!mcspi->base) {
dev_dbg(&pdev->dev, "can't ioremap MCSPI\n");
status = -ENOMEM;
goto err1aa;
}
INIT_WORK(&mcspi->work, omap2_mcspi_work);
spin_lock_init(&mcspi->lock);
INIT_LIST_HEAD(&mcspi->msg_queue);
mcspi->ick = clk_get(&pdev->dev, "ick");
if (IS_ERR(mcspi->ick)) {
dev_dbg(&pdev->dev, "can't get mcspi_ick\n");
status = PTR_ERR(mcspi->ick);
goto err1a;
}
mcspi->fck = clk_get(&pdev->dev, "fck");
if (IS_ERR(mcspi->fck)) {
dev_dbg(&pdev->dev, "can't get mcspi_fck\n");
status = PTR_ERR(mcspi->fck);
goto err2;
}
mcspi->dma_channels = kcalloc(master->num_chipselect,
sizeof(struct omap2_mcspi_dma),
GFP_KERNEL);
if (mcspi->dma_channels == NULL)
goto err3;
for (i = 0; i < num_chipselect; i++) {
mcspi->dma_channels[i].dma_rx_channel = -1;
mcspi->dma_channels[i].dma_rx_sync_dev = rxdma_id[i];
mcspi->dma_channels[i].dma_tx_channel = -1;
mcspi->dma_channels[i].dma_tx_sync_dev = txdma_id[i];
}
if (omap2_mcspi_reset(mcspi) < 0)
goto err4;
status = spi_register_master(master);
if (status < 0)
goto err4;
return status;
err4:
kfree(mcspi->dma_channels);
err3:
clk_put(mcspi->fck);
err2:
clk_put(mcspi->ick);
err1a:
iounmap(mcspi->base);
err1aa:
release_mem_region(r->start, (r->end - r->start) + 1);
err1:
spi_master_put(master);
return status;
}
static int __exit omap2_mcspi_remove(struct platform_device *pdev)
{
struct spi_master *master;
struct omap2_mcspi *mcspi;
struct omap2_mcspi_dma *dma_channels;
struct resource *r;
void __iomem *base;
master = dev_get_drvdata(&pdev->dev);
mcspi = spi_master_get_devdata(master);
dma_channels = mcspi->dma_channels;
clk_put(mcspi->fck);
clk_put(mcspi->ick);
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
release_mem_region(r->start, (r->end - r->start) + 1);
base = mcspi->base;
spi_unregister_master(master);
iounmap(base);
kfree(dma_channels);
return 0;
}
/* work with hotplug and coldplug */
MODULE_ALIAS("platform:omap2_mcspi");
static struct platform_driver omap2_mcspi_driver = {
.driver = {
.name = "omap2_mcspi",
.owner = THIS_MODULE,
},
.remove = __exit_p(omap2_mcspi_remove),
};
static int __init omap2_mcspi_init(void)
{
omap2_mcspi_wq = create_singlethread_workqueue(
omap2_mcspi_driver.driver.name);
if (omap2_mcspi_wq == NULL)
return -1;
return platform_driver_probe(&omap2_mcspi_driver, omap2_mcspi_probe);
}
subsys_initcall(omap2_mcspi_init);
static void __exit omap2_mcspi_exit(void)
{
platform_driver_unregister(&omap2_mcspi_driver);
destroy_workqueue(omap2_mcspi_wq);
}
module_exit(omap2_mcspi_exit);
MODULE_LICENSE("GPL");
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