From a41ae1ad907655b2efbb9b1a97736ab1451e1649 Mon Sep 17 00:00:00 2001 From: Hemanth V Date: Tue, 22 Sep 2009 16:46:16 -0700 Subject: [PATCH] spi: McSPI off-mode support Add context save/restore feature to McSPI driver. Signed-off-by: Hemanth V Reviewed-by: Aaro Koskinen Signed-off-by: Kevin Hilman Signed-off-by: David Brownell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/spi/omap2_mcspi.c | 134 ++++++++++++++++++++++++++++---------- 1 file changed, 100 insertions(+), 34 deletions(-) diff --git a/drivers/spi/omap2_mcspi.c b/drivers/spi/omap2_mcspi.c index ae785cc627b6..e96ad2709565 100644 --- a/drivers/spi/omap2_mcspi.c +++ b/drivers/spi/omap2_mcspi.c @@ -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; } -- 2.30.2