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linux/drivers/spi/omap2_mcspi.c
Ilkka Koskinen 2764c500be spi/omap2_mcspi: Verify TX reg is empty after TX only xfer with DMA 
In case of TX only with DMA, the driver assumes that the data
has been transferred once DMA callback in invoked. However,
SPI's shift register may still contain data. Thus, the driver
is supposed to verify that the register is empty and the end of
the SPI transfer has been reached.

Signed-off-by: Ilkka Koskinen <ilkka.koskinen@nokia.com>
Tested-by: Tuomas Katila <ext-tuomas.2.katila@nokia.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-10-20 10:43:24 -06:00

1336 lines
33 KiB
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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/slab.h>
#include <linux/spi/spi.h>
#include <plat/dma.h>
#include <plat/clock.h>
#include <plat/mcspi.h>
#define OMAP2_MCSPI_MAX_FREQ 48000000
/* OMAP2 has 3 SPI controllers, while OMAP3 has 4 */
#define OMAP2_MCSPI_MAX_CTRL 4
#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 BIT(4)
#define OMAP2_MCSPI_SYSCONFIG_ENAWAKEUP BIT(2)
#define OMAP2_MCSPI_SYSCONFIG_AUTOIDLE BIT(0)
#define OMAP2_MCSPI_SYSCONFIG_SOFTRESET BIT(1)
#define OMAP2_MCSPI_SYSSTATUS_RESETDONE BIT(0)
#define OMAP2_MCSPI_MODULCTRL_SINGLE BIT(0)
#define OMAP2_MCSPI_MODULCTRL_MS BIT(2)
#define OMAP2_MCSPI_MODULCTRL_STEST BIT(3)
#define OMAP2_MCSPI_CHCONF_PHA BIT(0)
#define OMAP2_MCSPI_CHCONF_POL BIT(1)
#define OMAP2_MCSPI_CHCONF_CLKD_MASK (0x0f << 2)
#define OMAP2_MCSPI_CHCONF_EPOL BIT(6)
#define OMAP2_MCSPI_CHCONF_WL_MASK (0x1f << 7)
#define OMAP2_MCSPI_CHCONF_TRM_RX_ONLY BIT(12)
#define OMAP2_MCSPI_CHCONF_TRM_TX_ONLY BIT(13)
#define OMAP2_MCSPI_CHCONF_TRM_MASK (0x03 << 12)
#define OMAP2_MCSPI_CHCONF_DMAW BIT(14)
#define OMAP2_MCSPI_CHCONF_DMAR BIT(15)
#define OMAP2_MCSPI_CHCONF_DPE0 BIT(16)
#define OMAP2_MCSPI_CHCONF_DPE1 BIT(17)
#define OMAP2_MCSPI_CHCONF_IS BIT(18)
#define OMAP2_MCSPI_CHCONF_TURBO BIT(19)
#define OMAP2_MCSPI_CHCONF_FORCE BIT(20)
#define OMAP2_MCSPI_CHSTAT_RXS BIT(0)
#define OMAP2_MCSPI_CHSTAT_TXS BIT(1)
#define OMAP2_MCSPI_CHSTAT_EOT BIT(2)
#define OMAP2_MCSPI_CHCTRL_EN BIT(0)
#define OMAP2_MCSPI_WAKEUPENABLE_WKEN BIT(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 160
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;
struct list_head node;
/* Context save and restore shadow register */
u32 chconf0;
};
/* used for context save and restore, structure members to be updated whenever
* corresponding registers are modified.
*/
struct omap2_mcspi_regs {
u32 sysconfig;
u32 modulctrl;
u32 wakeupenable;
struct list_head cs;
};
static struct omap2_mcspi_regs omap2_mcspi_ctx[OMAP2_MCSPI_MAX_CTRL];
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 inline u32 mcspi_cached_chconf0(const struct spi_device *spi)
{
struct omap2_mcspi_cs *cs = spi->controller_state;
return cs->chconf0;
}
static inline void mcspi_write_chconf0(const struct spi_device *spi, u32 val)
{
struct omap2_mcspi_cs *cs = spi->controller_state;
cs->chconf0 = val;
mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, val);
mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
}
static void omap2_mcspi_set_dma_req(const struct spi_device *spi,
int is_read, int enable)
{
u32 l, rw;
l = mcspi_cached_chconf0(spi);
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_chconf0(spi, 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);
/* Flash post-writes */
mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCTRL0);
}
static void omap2_mcspi_force_cs(struct spi_device *spi, int cs_active)
{
u32 l;
l = mcspi_cached_chconf0(spi);
MOD_REG_BIT(l, OMAP2_MCSPI_CHCONF_FORCE, cs_active);
mcspi_write_chconf0(spi, 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);
omap2_mcspi_ctx[master->bus_num - 1].modulctrl = l;
}
static void omap2_mcspi_restore_ctx(struct omap2_mcspi *mcspi)
{
struct spi_master *spi_cntrl;
struct omap2_mcspi_cs *cs;
spi_cntrl = mcspi->master;
/* McSPI: context restore */
mcspi_write_reg(spi_cntrl, OMAP2_MCSPI_MODULCTRL,
omap2_mcspi_ctx[spi_cntrl->bus_num - 1].modulctrl);
mcspi_write_reg(spi_cntrl, OMAP2_MCSPI_SYSCONFIG,
omap2_mcspi_ctx[spi_cntrl->bus_num - 1].sysconfig);
mcspi_write_reg(spi_cntrl, OMAP2_MCSPI_WAKEUPENABLE,
omap2_mcspi_ctx[spi_cntrl->bus_num - 1].wakeupenable);
list_for_each_entry(cs, &omap2_mcspi_ctx[spi_cntrl->bus_num - 1].cs,
node)
__raw_writel(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0);
}
static void omap2_mcspi_disable_clocks(struct omap2_mcspi *mcspi)
{
clk_disable(mcspi->ick);
clk_disable(mcspi->fck);
}
static int omap2_mcspi_enable_clocks(struct omap2_mcspi *mcspi)
{
if (clk_enable(mcspi->ick))
return -ENODEV;
if (clk_enable(mcspi->fck))
return -ENODEV;
omap2_mcspi_restore_ctx(mcspi);
return 0;
}
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_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;
int elements;
u32 l;
u8 * rx;
const u8 * tx;
void __iomem *chstat_reg;
mcspi = spi_master_get_devdata(spi->master);
mcspi_dma = &mcspi->dma_channels[spi->chip_select];
l = mcspi_cached_chconf0(spi);
chstat_reg = cs->base + OMAP2_MCSPI_CHSTAT0;
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) {
elements = element_count - 1;
if (l & OMAP2_MCSPI_CHCONF_TURBO)
elements--;
omap_set_dma_transfer_params(mcspi_dma->dma_rx_channel,
data_type, elements, 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);
/* for TX_ONLY mode, be sure all words have shifted out */
if (rx == 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");
}
}
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 (l & OMAP2_MCSPI_CHCONF_TURBO) {
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)[elements++] = w;
else if (word_len <= 16)
((u16 *)xfer->rx_buf)[elements++] = w;
else /* word_len <= 32 */
((u32 *)xfer->rx_buf)[elements++] = w;
} else {
dev_err(&spi->dev,
"DMA RX penultimate word empty");
count -= (word_len <= 8) ? 2 :
(word_len <= 16) ? 4 :
/* word_len <= 32 */ 8;
omap2_mcspi_set_enable(spi, 1);
return count;
}
}
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)[elements] = w;
else if (word_len <= 16)
((u16 *)xfer->rx_buf)[elements] = w;
else /* word_len <= 32 */
((u32 *)xfer->rx_buf)[elements] = 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 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_cached_chconf0(spi);
/* 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;
}
dev_vdbg(&spi->dev, "write-%d %02x\n",
word_len, *tx);
__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;
}
if (c == 1 && tx == NULL &&
(l & OMAP2_MCSPI_CHCONF_TURBO)) {
omap2_mcspi_set_enable(spi, 0);
*rx++ = __raw_readl(rx_reg);
dev_vdbg(&spi->dev, "read-%d %02x\n",
word_len, *(rx - 1));
if (mcspi_wait_for_reg_bit(chstat_reg,
OMAP2_MCSPI_CHSTAT_RXS) < 0) {
dev_err(&spi->dev,
"RXS timed out\n");
goto out;
}
c = 0;
} else if (c == 0 && tx == NULL) {
omap2_mcspi_set_enable(spi, 0);
}
*rx++ = __raw_readl(rx_reg);
dev_vdbg(&spi->dev, "read-%d %02x\n",
word_len, *(rx - 1));
}
} 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;
}
dev_vdbg(&spi->dev, "write-%d %04x\n",
word_len, *tx);
__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;
}
if (c == 2 && tx == NULL &&
(l & OMAP2_MCSPI_CHCONF_TURBO)) {
omap2_mcspi_set_enable(spi, 0);
*rx++ = __raw_readl(rx_reg);
dev_vdbg(&spi->dev, "read-%d %04x\n",
word_len, *(rx - 1));
if (mcspi_wait_for_reg_bit(chstat_reg,
OMAP2_MCSPI_CHSTAT_RXS) < 0) {
dev_err(&spi->dev,
"RXS timed out\n");
goto out;
}
c = 0;
} else if (c == 0 && tx == NULL) {
omap2_mcspi_set_enable(spi, 0);
}
*rx++ = __raw_readl(rx_reg);
dev_vdbg(&spi->dev, "read-%d %04x\n",
word_len, *(rx - 1));
}
} 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;
}
dev_vdbg(&spi->dev, "write-%d %08x\n",
word_len, *tx);
__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;
}
if (c == 4 && tx == NULL &&
(l & OMAP2_MCSPI_CHCONF_TURBO)) {
omap2_mcspi_set_enable(spi, 0);
*rx++ = __raw_readl(rx_reg);
dev_vdbg(&spi->dev, "read-%d %08x\n",
word_len, *(rx - 1));
if (mcspi_wait_for_reg_bit(chstat_reg,
OMAP2_MCSPI_CHSTAT_RXS) < 0) {
dev_err(&spi->dev,
"RXS timed out\n");
goto out;
}
c = 0;
} else if (c == 0 && tx == NULL) {
omap2_mcspi_set_enable(spi, 0);
}
*rx++ = __raw_readl(rx_reg);
dev_vdbg(&spi->dev, "read-%d %08x\n",
word_len, *(rx - 1));
}
} 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");
/* disable chan to purge rx datas received in TX_ONLY transfer,
* otherwise these rx datas will affect the direct following
* RX_ONLY transfer.
*/
omap2_mcspi_set_enable(spi, 0);
}
out:
omap2_mcspi_set_enable(spi, 1);
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;
struct spi_master *spi_cntrl;
u32 l = 0, div = 0;
u8 word_len = spi->bits_per_word;
u32 speed_hz = spi->max_speed_hz;
mcspi = spi_master_get_devdata(spi->master);
spi_cntrl = mcspi->master;
if (t != NULL && t->bits_per_word)
word_len = t->bits_per_word;
cs->word_len = word_len;
if (t && t->speed_hz)
speed_hz = t->speed_hz;
if (speed_hz) {
while (div <= 15 && (OMAP2_MCSPI_MAX_FREQ / (1 << div))
> speed_hz)
div++;
} else
div = 15;
l = mcspi_cached_chconf0(spi);
/* 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_chconf0(spi, 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;
cs->chconf0 = 0;
spi->controller_state = cs;
/* Link this to context save list */
list_add_tail(&cs->node,
&omap2_mcspi_ctx[mcspi->master->bus_num - 1].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;
}
if (omap2_mcspi_enable_clocks(mcspi))
return -ENODEV;
ret = omap2_mcspi_setup_transfer(spi, NULL);
omap2_mcspi_disable_clocks(mcspi);
return ret;
}
static void omap2_mcspi_cleanup(struct spi_device *spi)
{
struct omap2_mcspi *mcspi;
struct omap2_mcspi_dma *mcspi_dma;
struct omap2_mcspi_cs *cs;
mcspi = spi_master_get_devdata(spi->master);
if (spi->controller_state) {
/* Unlink controller state from context save list */
cs = spi->controller_state;
list_del(&cs->node);
kfree(spi->controller_state);
}
if (spi->chip_select < spi->master->num_chipselect) {
mcspi_dma = &mcspi->dma_channels[spi->chip_select];
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);
if (omap2_mcspi_enable_clocks(mcspi))
goto out;
/* 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;
struct omap2_mcspi_device_config *cd;
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;
cd = spi->controller_data;
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_cached_chconf0(spi);
chconf &= ~OMAP2_MCSPI_CHCONF_TRM_MASK;
chconf &= ~OMAP2_MCSPI_CHCONF_TURBO;
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;
if (cd && cd->turbo_mode && t->tx_buf == NULL) {
/* Turbo mode is for more than one word */
if (t->len > ((cs->word_len + 7) >> 3))
chconf |= OMAP2_MCSPI_CHCONF_TURBO;
}
mcspi_write_chconf0(spi, 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);
}
omap2_mcspi_disable_clocks(mcspi);
out:
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;
if (omap2_mcspi_enable_clocks(mcspi))
return -1;
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));
tmp = OMAP2_MCSPI_SYSCONFIG_AUTOIDLE |
OMAP2_MCSPI_SYSCONFIG_ENAWAKEUP |
OMAP2_MCSPI_SYSCONFIG_SMARTIDLE;
mcspi_write_reg(master, OMAP2_MCSPI_SYSCONFIG, tmp);
omap2_mcspi_ctx[master->bus_num - 1].sysconfig = tmp;
tmp = OMAP2_MCSPI_WAKEUPENABLE_WKEN;
mcspi_write_reg(master, OMAP2_MCSPI_WAKEUPENABLE, tmp);
omap2_mcspi_ctx[master->bus_num - 1].wakeupenable = tmp;
omap2_mcspi_set_master_mode(master);
omap2_mcspi_disable_clocks(mcspi);
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_OMAP3) \
|| defined(CONFIG_ARCH_OMAP4)
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
#if defined(CONFIG_ARCH_OMAP3) || defined(CONFIG_ARCH_OMAP4)
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) \
|| defined(CONFIG_ARCH_OMAP4)
case 3:
rxdma_id = spi3_rxdma_id;
txdma_id = spi3_txdma_id;
num_chipselect = 2;
break;
#endif
#if defined(CONFIG_ARCH_OMAP3) || defined(CONFIG_ARCH_OMAP4)
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);
INIT_LIST_HEAD(&omap2_mcspi_ctx[master->bus_num - 1].cs);
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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