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linux/drivers/spi/omap2_mcspi.c
Eero Nurkkala 57c5c28dbc spi: omap2_mcspi rxdma bugfix 
When data is read through DMA, the last element must be read separately
through the RX register.  It cannot be transferred by the DMA.  For
further details see e.g.  OMAP35x TRM (table 19-16).

Without the fix the driver causes extra clocks to be clocked to the bus
after DMA RX operations.  This can cause interesting behaviour with some
devices.

Signed-off-by: Juuso Oikarinen <juuso.oikarinen@nokia.com>
Signed-off-by: Eero Nurkkala <ext-eero.nurkkala@nokia.com>
[aaro.koskinen@nokia.com: Simplified the patch while keeping the idea.]
Signed-off-by: Aaro Koskinen <aaro.koskinen@nokia.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-29 19:10:35 -07:00

1150 lines
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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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