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linux-davinci
Commit a41ae1ad authored by Hemanth V's avatar Hemanth V Committed by Linus Torvalds
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spi: McSPI off-mode support 

Add context save/restore feature to McSPI driver.
Signed-off-by: default avatarHemanth V <hemanthv@ti.com>
Reviewed-by: default avatarAaro Koskinen <Aaro.Koskinen@nokia.com>
Signed-off-by: default avatarKevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: default avatarDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 0644c486
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Inline Side-by-side
Showing with 100 additions and 34 deletions
drivers/spi/omap2_mcspi.c
View file @ a41ae1ad
......@@ -41,6 +41,9 @@
#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
......@@ -131,8 +134,21 @@ struct omap2_mcspi_cs {
void __iomem *base;
unsigned long phys;
int word_len;
/* 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;
};
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 { \
......@@ -172,12 +188,27 @@ static inline u32 mcspi_read_cs_reg(const struct spi_device *spi, int idx)
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);
}
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);
l = mcspi_cached_chconf0(spi);
if (is_read) /* 1 is read, 0 write */
rw = OMAP2_MCSPI_CHCONF_DMAR;
......@@ -185,7 +216,7 @@ static void omap2_mcspi_set_dma_req(const struct spi_device *spi,
rw = OMAP2_MCSPI_CHCONF_DMAW;
MOD_REG_BIT(l, rw, enable);
mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, l);
mcspi_write_chconf0(spi, l);
}
static void omap2_mcspi_set_enable(const struct spi_device *spi, int enable)
......@@ -200,9 +231,9 @@ static void omap2_mcspi_force_cs(struct spi_device *spi, int cs_active)
{
u32 l;
l = mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
l = mcspi_cached_chconf0(spi);
MOD_REG_BIT(l, OMAP2_MCSPI_CHCONF_FORCE, cs_active);
mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, l);
mcspi_write_chconf0(spi, l);
}
static void omap2_mcspi_set_master_mode(struct spi_master *master)
......@@ -217,6 +248,41 @@ static void omap2_mcspi_set_master_mode(struct spi_master *master)
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;
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);
}
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 unsigned
......@@ -357,7 +423,7 @@ omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer)
c = count;
word_len = cs->word_len;
l = mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
l = mcspi_cached_chconf0(spi);
l &= ~OMAP2_MCSPI_CHCONF_TRM_MASK;
/* We store the pre-calculated register addresses on stack to speed
......@@ -397,8 +463,7 @@ omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer)
* more word i/o: switch to rx+tx
*/
if (c == 0 && tx == NULL)
mcspi_write_cs_reg(spi,
OMAP2_MCSPI_CHCONF0, l);
mcspi_write_chconf0(spi, l);
*rx++ = __raw_readl(rx_reg);
#ifdef VERBOSE
dev_dbg(&spi->dev, "read-%d %02x\n",
......@@ -436,8 +501,7 @@ omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer)
* more word i/o: switch to rx+tx
*/
if (c == 0 && tx == NULL)
mcspi_write_cs_reg(spi,
OMAP2_MCSPI_CHCONF0, l);
mcspi_write_chconf0(spi, l);
*rx++ = __raw_readl(rx_reg);
#ifdef VERBOSE
dev_dbg(&spi->dev, "read-%d %04x\n",
......@@ -475,8 +539,7 @@ omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer)
* more word i/o: switch to rx+tx
*/
if (c == 0 && tx == NULL)
mcspi_write_cs_reg(spi,
OMAP2_MCSPI_CHCONF0, l);
mcspi_write_chconf0(spi, l);
*rx++ = __raw_readl(rx_reg);
#ifdef VERBOSE
dev_dbg(&spi->dev, "read-%d %04x\n",
......@@ -505,10 +568,12 @@ static int omap2_mcspi_setup_transfer(struct spi_device *spi,
{
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;
mcspi = spi_master_get_devdata(spi->master);
spi_cntrl = mcspi->master;
if (t != NULL && t->bits_per_word)
word_len = t->bits_per_word;
......@@ -522,7 +587,7 @@ static int omap2_mcspi_setup_transfer(struct spi_device *spi,
} else
div = 15;
l = mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
l = mcspi_cached_chconf0(spi);
/* standard 4-wire master mode: SCK, MOSI/out, MISO/in, nCS
* REVISIT: this controller could support SPI_3WIRE mode.
......@@ -554,7 +619,7 @@ static int omap2_mcspi_setup_transfer(struct spi_device *spi,
else
l &= ~OMAP2_MCSPI_CHCONF_PHA;
mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, l);
mcspi_write_chconf0(spi, l);
dev_dbg(&spi->dev, "setup: speed %d, sample %s edge, clk %s\n",
OMAP2_MCSPI_MAX_FREQ / (1 << div),
......@@ -647,6 +712,7 @@ static int omap2_mcspi_setup(struct spi_device *spi)
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;
}
......@@ -657,11 +723,11 @@ static int omap2_mcspi_setup(struct spi_device *spi)
return ret;
}
clk_enable(mcspi->ick);
clk_enable(mcspi->fck);
if (omap2_mcspi_enable_clocks(mcspi))
return -ENODEV;
ret = omap2_mcspi_setup_transfer(spi, NULL);
clk_disable(mcspi->fck);
clk_disable(mcspi->ick);
omap2_mcspi_disable_clocks(mcspi);
return ret;
}
......@@ -693,8 +759,8 @@ static void omap2_mcspi_work(struct work_struct *work)
mcspi = container_of(work, struct omap2_mcspi, work);
spin_lock_irq(&mcspi->lock);
clk_enable(mcspi->ick);
clk_enable(mcspi->fck);
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
......@@ -741,13 +807,13 @@ static void omap2_mcspi_work(struct work_struct *work)
cs_active = 1;
}
chconf = mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
chconf = mcspi_cached_chconf0(spi);
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);
mcspi_write_chconf0(spi, chconf);
if (t->len) {
unsigned count;
......@@ -796,9 +862,9 @@ static void omap2_mcspi_work(struct work_struct *work)
spin_lock_irq(&mcspi->lock);
}
clk_disable(mcspi->fck);
clk_disable(mcspi->ick);
omap2_mcspi_disable_clocks(mcspi);
out:
spin_unlock_irq(&mcspi->lock);
}
......@@ -885,8 +951,8 @@ 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);
if (omap2_mcspi_enable_clocks(mcspi))
return -1;
mcspi_write_reg(master, OMAP2_MCSPI_SYSCONFIG,
OMAP2_MCSPI_SYSCONFIG_SOFTRESET);
......@@ -894,18 +960,18 @@ static int __init omap2_mcspi_reset(struct omap2_mcspi *mcspi)
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);
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;
mcspi_write_reg(master, OMAP2_MCSPI_WAKEUPENABLE,
OMAP2_MCSPI_WAKEUPENABLE_WKEN);
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);
clk_disable(mcspi->fck);
clk_disable(mcspi->ick);
omap2_mcspi_disable_clocks(mcspi);
return 0;
}
......
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