The patch spi: imx: dynamic burst length adjust for PIO mode has been applied to the spi tree at git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted. You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed. If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced. Please add any relevant lists and maintainers to the CCs when replying to this mail. Thanks, Mark >From a0cc330240c9dae8e3080bd6dc59adb2bdc792ce Mon Sep 17 00:00:00 2001 From: Jiada Wang <jiada_wang@xxxxxxxxxx> Date: Tue, 13 Jun 2017 17:34:02 +0900 Subject: [PATCH] spi: imx: dynamic burst length adjust for PIO mode previously burst length (BURST_LENGTH) is always set to equal to bits_per_word, causes a 10us gap between each word in transfer, which significantly affects performance. This patch uses 32 bits transfer to simulate lower bits transfer, and adjusts burst length runtimely to use biggeest burst length as possible to reduce the gaps in transfer for PIO mode. Signed-off-by: Jiada Wang <jiada_wang@xxxxxxxxxx> Signed-off-by: Mark Brown <broonie@xxxxxxxxxx> --- drivers/spi/spi-imx.c | 150 +++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 141 insertions(+), 9 deletions(-) diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c index f9698b7aeb3b..88f52d24e2ab 100644 --- a/drivers/spi/spi-imx.c +++ b/drivers/spi/spi-imx.c @@ -56,6 +56,7 @@ /* The maximum bytes that a sdma BD can transfer.*/ #define MAX_SDMA_BD_BYTES (1 << 15) +#define MX51_ECSPI_CTRL_MAX_BURST 512 enum spi_imx_devtype { IMX1_CSPI, @@ -74,6 +75,7 @@ struct spi_imx_devtype_data { void (*trigger)(struct spi_imx_data *); int (*rx_available)(struct spi_imx_data *); void (*reset)(struct spi_imx_data *); + bool dynamic_burst; enum spi_imx_devtype devtype; }; @@ -94,12 +96,14 @@ struct spi_imx_data { unsigned int bits_per_word; unsigned int spi_drctl; - unsigned int count; + unsigned int count, remainder; void (*tx)(struct spi_imx_data *); void (*rx)(struct spi_imx_data *); void *rx_buf; const void *tx_buf; unsigned int txfifo; /* number of words pushed in tx FIFO */ + unsigned int dynamic_burst, read_u32; + unsigned int word_mask; /* DMA */ bool usedma; @@ -228,6 +232,7 @@ static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi, return false; spi_imx->wml = i; + spi_imx->dynamic_burst = 0; return true; } @@ -242,6 +247,7 @@ static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi, #define MX51_ECSPI_CTRL_PREDIV_OFFSET 12 #define MX51_ECSPI_CTRL_CS(cs) ((cs) << 18) #define MX51_ECSPI_CTRL_BL_OFFSET 20 +#define MX51_ECSPI_CTRL_BL_MASK (0xfff << 20) #define MX51_ECSPI_CONFIG 0x0c #define MX51_ECSPI_CONFIG_SCLKPHA(cs) (1 << ((cs) + 0)) @@ -269,6 +275,102 @@ static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi, #define MX51_ECSPI_TESTREG 0x20 #define MX51_ECSPI_TESTREG_LBC BIT(31) +static void spi_imx_buf_rx_swap_u32(struct spi_imx_data *spi_imx) +{ + unsigned int val = readl(spi_imx->base + MXC_CSPIRXDATA); + unsigned int bytes_per_word; + + if (spi_imx->rx_buf) { +#ifdef __LITTLE_ENDIAN + bytes_per_word = spi_imx_bytes_per_word(spi_imx->bits_per_word); + if (bytes_per_word == 1) + val = cpu_to_be32(val); + else if (bytes_per_word == 2) + val = (val << 16) | (val >> 16); +#endif + val &= spi_imx->word_mask; + *(u32 *)spi_imx->rx_buf = val; + spi_imx->rx_buf += sizeof(u32); + } +} + +static void spi_imx_buf_rx_swap(struct spi_imx_data *spi_imx) +{ + unsigned int bytes_per_word; + + bytes_per_word = spi_imx_bytes_per_word(spi_imx->bits_per_word); + if (spi_imx->read_u32) { + spi_imx_buf_rx_swap_u32(spi_imx); + return; + } + + if (bytes_per_word == 1) + spi_imx_buf_rx_u8(spi_imx); + else if (bytes_per_word == 2) + spi_imx_buf_rx_u16(spi_imx); +} + +static void spi_imx_buf_tx_swap_u32(struct spi_imx_data *spi_imx) +{ + u32 val = 0; + unsigned int bytes_per_word; + + if (spi_imx->tx_buf) { + val = *(u32 *)spi_imx->tx_buf; + val &= spi_imx->word_mask; + spi_imx->tx_buf += sizeof(u32); + } + + spi_imx->count -= sizeof(u32); +#ifdef __LITTLE_ENDIAN + bytes_per_word = spi_imx_bytes_per_word(spi_imx->bits_per_word); + + if (bytes_per_word == 1) + val = cpu_to_be32(val); + else if (bytes_per_word == 2) + val = (val << 16) | (val >> 16); +#endif + writel(val, spi_imx->base + MXC_CSPITXDATA); +} + +static void spi_imx_buf_tx_swap(struct spi_imx_data *spi_imx) +{ + u32 ctrl, val; + unsigned int bytes_per_word; + + if (spi_imx->count == spi_imx->remainder) { + ctrl = readl(spi_imx->base + MX51_ECSPI_CTRL); + ctrl &= ~MX51_ECSPI_CTRL_BL_MASK; + if (spi_imx->count > MX51_ECSPI_CTRL_MAX_BURST) { + spi_imx->remainder = spi_imx->count % + MX51_ECSPI_CTRL_MAX_BURST; + val = MX51_ECSPI_CTRL_MAX_BURST; + } else if (spi_imx->count >= sizeof(u32)) { + spi_imx->remainder = spi_imx->count % sizeof(u32); + val = (spi_imx->count - spi_imx->remainder) * 8 - 1; + } else { + spi_imx->remainder = 0; + val = spi_imx->bits_per_word - 1; + spi_imx->read_u32 = 0; + } + + ctrl |= (val << MX51_ECSPI_CTRL_BL_OFFSET); + writel(ctrl, spi_imx->base + MX51_ECSPI_CTRL); + } + + if (spi_imx->count >= sizeof(u32)) { + spi_imx_buf_tx_swap_u32(spi_imx); + return; + } + + bytes_per_word = spi_imx_bytes_per_word(spi_imx->bits_per_word); + + if (bytes_per_word == 1) + spi_imx_buf_tx_u8(spi_imx); + else if (bytes_per_word == 2) + spi_imx_buf_tx_u16(spi_imx); +} + /* MX51 eCSPI */ static unsigned int mx51_ecspi_clkdiv(struct spi_imx_data *spi_imx, unsigned int fspi, unsigned int *fres) @@ -693,6 +795,7 @@ static struct spi_imx_devtype_data imx1_cspi_devtype_data = { .trigger = mx1_trigger, .rx_available = mx1_rx_available, .reset = mx1_reset, + .dynamic_burst = false, .devtype = IMX1_CSPI, }; @@ -702,6 +805,7 @@ static struct spi_imx_devtype_data imx21_cspi_devtype_data = { .trigger = mx21_trigger, .rx_available = mx21_rx_available, .reset = mx21_reset, + .dynamic_burst = false, .devtype = IMX21_CSPI, }; @@ -712,6 +816,7 @@ static struct spi_imx_devtype_data imx27_cspi_devtype_data = { .trigger = mx21_trigger, .rx_available = mx21_rx_available, .reset = mx21_reset, + .dynamic_burst = false, .devtype = IMX27_CSPI, }; @@ -721,6 +826,7 @@ static struct spi_imx_devtype_data imx31_cspi_devtype_data = { .trigger = mx31_trigger, .rx_available = mx31_rx_available, .reset = mx31_reset, + .dynamic_burst = false, .devtype = IMX31_CSPI, }; @@ -731,6 +837,7 @@ static struct spi_imx_devtype_data imx35_cspi_devtype_data = { .trigger = mx31_trigger, .rx_available = mx31_rx_available, .reset = mx31_reset, + .dynamic_burst = false, .devtype = IMX35_CSPI, }; @@ -740,6 +847,7 @@ static struct spi_imx_devtype_data imx51_ecspi_devtype_data = { .trigger = mx51_ecspi_trigger, .rx_available = mx51_ecspi_rx_available, .reset = mx51_ecspi_reset, + .dynamic_burst = true, .devtype = IMX51_ECSPI, }; @@ -794,6 +902,8 @@ static void spi_imx_push(struct spi_imx_data *spi_imx) while (spi_imx->txfifo < spi_imx_get_fifosize(spi_imx)) { if (!spi_imx->count) break; + if (spi_imx->txfifo && (spi_imx->count == spi_imx->remainder)) + break; spi_imx->tx(spi_imx); spi_imx->txfifo++; } @@ -887,15 +997,37 @@ static int spi_imx_setupxfer(struct spi_device *spi, spi_imx->speed_hz = t->speed_hz; /* Initialize the functions for transfer */ - if (spi_imx->bits_per_word <= 8) { - spi_imx->rx = spi_imx_buf_rx_u8; - spi_imx->tx = spi_imx_buf_tx_u8; - } else if (spi_imx->bits_per_word <= 16) { - spi_imx->rx = spi_imx_buf_rx_u16; - spi_imx->tx = spi_imx_buf_tx_u16; + if (spi_imx->devtype_data->dynamic_burst) { + u32 mask; + + spi_imx->dynamic_burst = 0; + spi_imx->remainder = 0; + spi_imx->read_u32 = 1; + + mask = (1 << config.bpw) - 1; + spi_imx->rx = spi_imx_buf_rx_swap; + spi_imx->tx = spi_imx_buf_tx_swap; + spi_imx->dynamic_burst = 1; + spi_imx->remainder = t->len; + + if (spi_imx->bits_per_word <= 8) + spi_imx->word_mask = mask << 24 | mask << 16 + | mask << 8 | mask; + else if (spi_imx->bits_per_word <= 16) + spi_imx->word_mask = mask << 16 | mask; + else + spi_imx->word_mask = mask; } else { - spi_imx->rx = spi_imx_buf_rx_u32; - spi_imx->tx = spi_imx_buf_tx_u32; + if (spi_imx->bits_per_word <= 8) { + spi_imx->rx = spi_imx_buf_rx_u8; + spi_imx->tx = spi_imx_buf_tx_u8; + } else if (spi_imx->bits_per_word <= 16) { + spi_imx->rx = spi_imx_buf_rx_u16; + spi_imx->tx = spi_imx_buf_tx_u16; + } else { + spi_imx->rx = spi_imx_buf_rx_u32; + spi_imx->tx = spi_imx_buf_tx_u32; + } } if (spi_imx_can_dma(spi_imx->bitbang.master, spi, t)) -- 2.13.2 -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html