From 44b37eb79e16a56cb30ba55b2da452396b941e7a Mon Sep 17 00:00:00 2001 From: "leilk.liu" Date: Wed, 1 Jul 2020 17:00:20 +0800 Subject: [PATCH 1/2] spi: mediatek: use correct SPI_CFG2_REG MACRO this patch use correct SPI_CFG2_REG offset. Signed-off-by: leilk.liu Link: https://lore.kernel.org/r/20200701090020.7935-1-leilk.liu@mediatek.com Signed-off-by: Mark Brown --- drivers/spi/spi-mt65xx.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/drivers/spi/spi-mt65xx.c b/drivers/spi/spi-mt65xx.c index 6783e12c40c2..a556795caeef 100644 --- a/drivers/spi/spi-mt65xx.c +++ b/drivers/spi/spi-mt65xx.c @@ -36,7 +36,6 @@ #define SPI_CFG0_SCK_LOW_OFFSET 8 #define SPI_CFG0_CS_HOLD_OFFSET 16 #define SPI_CFG0_CS_SETUP_OFFSET 24 -#define SPI_ADJUST_CFG0_SCK_LOW_OFFSET 16 #define SPI_ADJUST_CFG0_CS_HOLD_OFFSET 0 #define SPI_ADJUST_CFG0_CS_SETUP_OFFSET 16 @@ -48,6 +47,8 @@ #define SPI_CFG1_CS_IDLE_MASK 0xff #define SPI_CFG1_PACKET_LOOP_MASK 0xff00 #define SPI_CFG1_PACKET_LENGTH_MASK 0x3ff0000 +#define SPI_CFG2_SCK_HIGH_OFFSET 0 +#define SPI_CFG2_SCK_LOW_OFFSET 16 #define SPI_CMD_ACT BIT(0) #define SPI_CMD_RESUME BIT(1) @@ -283,7 +284,7 @@ static void mtk_spi_set_cs(struct spi_device *spi, bool enable) static void mtk_spi_prepare_transfer(struct spi_master *master, struct spi_transfer *xfer) { - u32 spi_clk_hz, div, sck_time, cs_time, reg_val = 0; + u32 spi_clk_hz, div, sck_time, cs_time, reg_val; struct mtk_spi *mdata = spi_master_get_devdata(master); spi_clk_hz = clk_get_rate(mdata->spi_clk); @@ -296,18 +297,18 @@ static void mtk_spi_prepare_transfer(struct spi_master *master, cs_time = sck_time * 2; if (mdata->dev_comp->enhance_timing) { + reg_val = (((sck_time - 1) & 0xffff) + << SPI_CFG2_SCK_HIGH_OFFSET); reg_val |= (((sck_time - 1) & 0xffff) - << SPI_CFG0_SCK_HIGH_OFFSET); - reg_val |= (((sck_time - 1) & 0xffff) - << SPI_ADJUST_CFG0_SCK_LOW_OFFSET); + << SPI_CFG2_SCK_LOW_OFFSET); writel(reg_val, mdata->base + SPI_CFG2_REG); - reg_val |= (((cs_time - 1) & 0xffff) + reg_val = (((cs_time - 1) & 0xffff) << SPI_ADJUST_CFG0_CS_HOLD_OFFSET); reg_val |= (((cs_time - 1) & 0xffff) << SPI_ADJUST_CFG0_CS_SETUP_OFFSET); writel(reg_val, mdata->base + SPI_CFG0_REG); } else { - reg_val |= (((sck_time - 1) & 0xff) + reg_val = (((sck_time - 1) & 0xff) << SPI_CFG0_SCK_HIGH_OFFSET); reg_val |= (((sck_time - 1) & 0xff) << SPI_CFG0_SCK_LOW_OFFSET); reg_val |= (((cs_time - 1) & 0xff) << SPI_CFG0_CS_HOLD_OFFSET); From ed7815db70d17b1741883f2da8e1d80bc2efe517 Mon Sep 17 00:00:00 2001 From: Marc Kleine-Budde Date: Mon, 6 Jul 2020 16:34:34 +0200 Subject: [PATCH 2/2] spi: spi-sun6i: sun6i_spi_transfer_one(): fix setting of clock rate A SPI transfer defines the _maximum_ speed of the SPI transfer. However the driver doesn't take into account that the clock divider is always rounded down (due to integer arithmetics). This results in a too high clock rate for the SPI transfer. E.g.: with a mclk_rate of 24 MHz and a SPI transfer speed of 10 MHz, the original code calculates a reg of "0", which results in a effective divider of "2" and a 12 MHz clock for the SPI transfer. This patch fixes the issue by using DIV_ROUND_UP() instead of a plain integer division. While there simplify the divider calculation for the CDR1 case, use order_base_2() instead of two ilog2() calculations. Fixes: 3558fe900e8a ("spi: sunxi: Add Allwinner A31 SPI controller driver") Signed-off-by: Marc Kleine-Budde Acked-by: Maxime Ripard Link: https://lore.kernel.org/r/20200706143443.9855-2-mkl@pengutronix.de Signed-off-by: Mark Brown --- drivers/spi/spi-sun6i.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c index ecea15534c42..fa11cc0e809b 100644 --- a/drivers/spi/spi-sun6i.c +++ b/drivers/spi/spi-sun6i.c @@ -198,7 +198,7 @@ static int sun6i_spi_transfer_one(struct spi_master *master, struct spi_transfer *tfr) { struct sun6i_spi *sspi = spi_master_get_devdata(master); - unsigned int mclk_rate, div, timeout; + unsigned int mclk_rate, div, div_cdr1, div_cdr2, timeout; unsigned int start, end, tx_time; unsigned int trig_level; unsigned int tx_len = 0; @@ -287,14 +287,12 @@ static int sun6i_spi_transfer_one(struct spi_master *master, * First try CDR2, and if we can't reach the expected * frequency, fall back to CDR1. */ - div = mclk_rate / (2 * tfr->speed_hz); - if (div <= (SUN6I_CLK_CTL_CDR2_MASK + 1)) { - if (div > 0) - div--; - - reg = SUN6I_CLK_CTL_CDR2(div) | SUN6I_CLK_CTL_DRS; + div_cdr1 = DIV_ROUND_UP(mclk_rate, tfr->speed_hz); + div_cdr2 = DIV_ROUND_UP(div_cdr1, 2); + if (div_cdr2 <= (SUN6I_CLK_CTL_CDR2_MASK + 1)) { + reg = SUN6I_CLK_CTL_CDR2(div_cdr2 - 1) | SUN6I_CLK_CTL_DRS; } else { - div = ilog2(mclk_rate) - ilog2(tfr->speed_hz); + div = min(SUN6I_CLK_CTL_CDR1_MASK, order_base_2(div_cdr1)); reg = SUN6I_CLK_CTL_CDR1(div); }