From 8b66c13474e1683d53255f3b2948231b61cdaefd Mon Sep 17 00:00:00 2001 From: Roman Tereshonkov Date: Mon, 12 Apr 2010 09:07:54 +0000 Subject: spi/omap2_mcspi: change default DMA_MIN_BYTES value to 160 The value 160 has been obtained as optimal in testing it for wl1271 which use spi for communication. In some sense this change might also influence on other spi devices connected to omap2_mcspi controller. Signed-off-by: Roman Tereshonkov Signed-off-by: Grant Likely --- drivers/spi/omap2_mcspi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/spi/omap2_mcspi.c') diff --git a/drivers/spi/omap2_mcspi.c b/drivers/spi/omap2_mcspi.c index e0de0d0..e6d08b8 100644 --- a/drivers/spi/omap2_mcspi.c +++ b/drivers/spi/omap2_mcspi.c @@ -113,7 +113,7 @@ struct omap2_mcspi_dma { /* use PIO for small transfers, avoiding DMA setup/teardown overhead and * cache operations; better heuristics consider wordsize and bitrate. */ -#define DMA_MIN_BYTES 8 +#define DMA_MIN_BYTES 160 struct omap2_mcspi { -- cgit v1.1 From 4743a0f88c4000dfa3c422ecc4d750d3a3410550 Mon Sep 17 00:00:00 2001 From: Roman Tereshonkov Date: Tue, 13 Apr 2010 10:41:51 +0000 Subject: spi/omap2_mcspi: add turbo mode support Turbo mode allows to read data to shift register when rx-buffer is full thus improving the perfomance. This feature is available for RX-only mode. In PIO turbo mode when the penultimate word is available in RX-buffer the controller should be disabled before reading data to prevent the next transaction triggering. The controller itself handles the last word to be correctly loaded to shift-register and then transferred to RX-buffer. The turbo mode is enabled by setting turbo_mode parameter to 1. This parameter is a part of omap2_mcspi_device_config structure which is passed through the spi_device controller_data pointer. Signed-off-by: Roman Tereshonkov Signed-off-by: Grant Likely --- drivers/spi/omap2_mcspi.c | 132 ++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 111 insertions(+), 21 deletions(-) (limited to 'drivers/spi/omap2_mcspi.c') diff --git a/drivers/spi/omap2_mcspi.c b/drivers/spi/omap2_mcspi.c index e6d08b8..6df8553 100644 --- a/drivers/spi/omap2_mcspi.c +++ b/drivers/spi/omap2_mcspi.c @@ -38,7 +38,7 @@ #include #include - +#include #define OMAP2_MCSPI_MAX_FREQ 48000000 @@ -229,6 +229,8 @@ static void omap2_mcspi_set_enable(const struct spi_device *spi, int enable) 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) @@ -303,11 +305,14 @@ omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer) 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; mcspi = spi_master_get_devdata(spi->master); mcspi_dma = &mcspi->dma_channels[spi->chip_select]; + l = mcspi_cached_chconf0(spi); count = xfer->len; c = count; @@ -346,8 +351,12 @@ omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer) } 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, element_count - 1, 1, + data_type, elements, 1, OMAP_DMA_SYNC_ELEMENT, mcspi_dma->dma_rx_sync_dev, 1); @@ -379,17 +388,42 @@ omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer) 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)[element_count - 1] = w; + ((u8 *)xfer->rx_buf)[elements] = w; else if (word_len <= 16) - ((u16 *)xfer->rx_buf)[element_count - 1] = w; + ((u16 *)xfer->rx_buf)[elements] = w; else /* word_len <= 32 */ - ((u32 *)xfer->rx_buf)[element_count - 1] = w; + ((u32 *)xfer->rx_buf)[elements] = w; } else { dev_err(&spi->dev, "DMA RX last word empty"); count -= (word_len <= 8) ? 1 : @@ -433,7 +467,6 @@ omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer) word_len = cs->word_len; l = mcspi_cached_chconf0(spi); - l &= ~OMAP2_MCSPI_CHCONF_TRM_MASK; /* We store the pre-calculated register addresses on stack to speed * up the transfer loop. */ @@ -468,11 +501,26 @@ omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer) 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_chconf0(spi, l); + + if (c == 1 && tx == NULL && + (l & OMAP2_MCSPI_CHCONF_TURBO)) { + omap2_mcspi_set_enable(spi, 0); + *rx++ = __raw_readl(rx_reg); +#ifdef VERBOSE + dev_dbg(&spi->dev, "read-%d %02x\n", + word_len, *(rx - 1)); +#endif + 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); #ifdef VERBOSE dev_dbg(&spi->dev, "read-%d %02x\n", @@ -506,11 +554,26 @@ omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer) 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_chconf0(spi, l); + + if (c == 2 && tx == NULL && + (l & OMAP2_MCSPI_CHCONF_TURBO)) { + omap2_mcspi_set_enable(spi, 0); + *rx++ = __raw_readl(rx_reg); +#ifdef VERBOSE + dev_dbg(&spi->dev, "read-%d %04x\n", + word_len, *(rx - 1)); +#endif + 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); #ifdef VERBOSE dev_dbg(&spi->dev, "read-%d %04x\n", @@ -544,11 +607,26 @@ omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer) 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_chconf0(spi, l); + + if (c == 4 && tx == NULL && + (l & OMAP2_MCSPI_CHCONF_TURBO)) { + omap2_mcspi_set_enable(spi, 0); + *rx++ = __raw_readl(rx_reg); +#ifdef VERBOSE + dev_dbg(&spi->dev, "read-%d %08x\n", + word_len, *(rx - 1)); +#endif + 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); #ifdef VERBOSE dev_dbg(&spi->dev, "read-%d %08x\n", @@ -568,6 +646,7 @@ omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer) dev_err(&spi->dev, "EOT timed out\n"); } out: + omap2_mcspi_set_enable(spi, 1); return count - c; } @@ -797,6 +876,7 @@ static void omap2_mcspi_work(struct work_struct *work) 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; @@ -809,6 +889,7 @@ static void omap2_mcspi_work(struct work_struct *work) 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) { @@ -832,10 +913,19 @@ static void omap2_mcspi_work(struct work_struct *work) 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) { -- cgit v1.1 From 99f1a43f436a6a92d15bddfeb65f3a920c8b88d3 Mon Sep 17 00:00:00 2001 From: Scott Ellis Date: Mon, 24 May 2010 14:20:27 +0000 Subject: spi/omap2_mcspi: Check params before dereference or use Check spi->chip_select for range before use. Signed-off-by: Scott Ellis Signed-off-by: Grant Likely --- drivers/spi/omap2_mcspi.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) (limited to 'drivers/spi/omap2_mcspi.c') diff --git a/drivers/spi/omap2_mcspi.c b/drivers/spi/omap2_mcspi.c index 6df8553..b3a94ca 100644 --- a/drivers/spi/omap2_mcspi.c +++ b/drivers/spi/omap2_mcspi.c @@ -834,7 +834,6 @@ static void omap2_mcspi_cleanup(struct spi_device *spi) struct omap2_mcspi_cs *cs; mcspi = spi_master_get_devdata(spi->master); - mcspi_dma = &mcspi->dma_channels[spi->chip_select]; if (spi->controller_state) { /* Unlink controller state from context save list */ @@ -844,13 +843,17 @@ static void omap2_mcspi_cleanup(struct spi_device *spi) 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; + 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; + } } } -- cgit v1.1