From b42a81ca0fa7b3b442a0731ffc4e7db44464b5f2 Mon Sep 17 00:00:00 2001 From: Jassi Brar Date: Wed, 29 Sep 2010 17:31:33 +0900 Subject: [PATCH] spi/s3c64xx: Consider the clk_from_cmu flag Newer SoCs have the SPI clock scaling control in platform's clock management unit. Inorder for such SoCs to work, we need to check the flag clk_from_cmu before making any clock changes. Signed-off-by: Jassi Brar Signed-off-by: Grant Likely --- .../plat-samsung/include/plat/s3c64xx-spi.h | 3 + drivers/spi/spi_s3c64xx.c | 94 +++++++++++-------- 2 files changed, 59 insertions(+), 38 deletions(-) diff --git a/arch/arm/plat-samsung/include/plat/s3c64xx-spi.h b/arch/arm/plat-samsung/include/plat/s3c64xx-spi.h index e5aba8f95b79..b226f7405e6b 100644 --- a/arch/arm/plat-samsung/include/plat/s3c64xx-spi.h +++ b/arch/arm/plat-samsung/include/plat/s3c64xx-spi.h @@ -32,6 +32,8 @@ struct s3c64xx_spi_csinfo { * struct s3c64xx_spi_info - SPI Controller defining structure * @src_clk_nr: Clock source index for the CLK_CFG[SPI_CLKSEL] field. * @src_clk_name: Platform name of the corresponding clock. + * @clk_from_cmu: If the SPI clock/prescalar control block is present + * by the platform's clock-management-unit and not in SPI controller. * @num_cs: Number of CS this controller emulates. * @cfg_gpio: Configure pins for this SPI controller. * @fifo_lvl_mask: All tx fifo_lvl fields start at offset-6 @@ -41,6 +43,7 @@ struct s3c64xx_spi_csinfo { struct s3c64xx_spi_info { int src_clk_nr; char *src_clk_name; + bool clk_from_cmu; int num_cs; diff --git a/drivers/spi/spi_s3c64xx.c b/drivers/spi/spi_s3c64xx.c index e7b893f2a21b..9e0aa3c7b4d1 100644 --- a/drivers/spi/spi_s3c64xx.c +++ b/drivers/spi/spi_s3c64xx.c @@ -399,13 +399,18 @@ static inline void disable_cs(struct s3c64xx_spi_driver_data *sdd, static void s3c64xx_spi_config(struct s3c64xx_spi_driver_data *sdd) { + struct s3c64xx_spi_info *sci = sdd->cntrlr_info; void __iomem *regs = sdd->regs; u32 val; /* Disable Clock */ - val = readl(regs + S3C64XX_SPI_CLK_CFG); - val &= ~S3C64XX_SPI_ENCLK_ENABLE; - writel(val, regs + S3C64XX_SPI_CLK_CFG); + if (sci->clk_from_cmu) { + clk_disable(sdd->src_clk); + } else { + val = readl(regs + S3C64XX_SPI_CLK_CFG); + val &= ~S3C64XX_SPI_ENCLK_ENABLE; + writel(val, regs + S3C64XX_SPI_CLK_CFG); + } /* Set Polarity and Phase */ val = readl(regs + S3C64XX_SPI_CH_CFG); @@ -441,17 +446,25 @@ static void s3c64xx_spi_config(struct s3c64xx_spi_driver_data *sdd) writel(val, regs + S3C64XX_SPI_MODE_CFG); - /* Configure Clock */ - val = readl(regs + S3C64XX_SPI_CLK_CFG); - val &= ~S3C64XX_SPI_PSR_MASK; - val |= ((clk_get_rate(sdd->src_clk) / sdd->cur_speed / 2 - 1) - & S3C64XX_SPI_PSR_MASK); - writel(val, regs + S3C64XX_SPI_CLK_CFG); - - /* Enable Clock */ - val = readl(regs + S3C64XX_SPI_CLK_CFG); - val |= S3C64XX_SPI_ENCLK_ENABLE; - writel(val, regs + S3C64XX_SPI_CLK_CFG); + if (sci->clk_from_cmu) { + /* Configure Clock */ + /* There is half-multiplier before the SPI */ + clk_set_rate(sdd->src_clk, sdd->cur_speed * 2); + /* Enable Clock */ + clk_enable(sdd->src_clk); + } else { + /* Configure Clock */ + val = readl(regs + S3C64XX_SPI_CLK_CFG); + val &= ~S3C64XX_SPI_PSR_MASK; + val |= ((clk_get_rate(sdd->src_clk) / sdd->cur_speed / 2 - 1) + & S3C64XX_SPI_PSR_MASK); + writel(val, regs + S3C64XX_SPI_CLK_CFG); + + /* Enable Clock */ + val = readl(regs + S3C64XX_SPI_CLK_CFG); + val |= S3C64XX_SPI_ENCLK_ENABLE; + writel(val, regs + S3C64XX_SPI_CLK_CFG); + } } static void s3c64xx_spi_dma_rxcb(struct s3c2410_dma_chan *chan, void *buf_id, @@ -806,7 +819,6 @@ static int s3c64xx_spi_setup(struct spi_device *spi) struct s3c64xx_spi_driver_data *sdd; struct s3c64xx_spi_info *sci; struct spi_message *msg; - u32 psr, speed; unsigned long flags; int err = 0; @@ -849,32 +861,37 @@ static int s3c64xx_spi_setup(struct spi_device *spi) } /* Check if we can provide the requested rate */ - speed = clk_get_rate(sdd->src_clk) / 2 / (0 + 1); /* Max possible */ - - if (spi->max_speed_hz > speed) - spi->max_speed_hz = speed; - - psr = clk_get_rate(sdd->src_clk) / 2 / spi->max_speed_hz - 1; - psr &= S3C64XX_SPI_PSR_MASK; - if (psr == S3C64XX_SPI_PSR_MASK) - psr--; + if (!sci->clk_from_cmu) { + u32 psr, speed; + + /* Max possible */ + speed = clk_get_rate(sdd->src_clk) / 2 / (0 + 1); + + if (spi->max_speed_hz > speed) + spi->max_speed_hz = speed; + + psr = clk_get_rate(sdd->src_clk) / 2 / spi->max_speed_hz - 1; + psr &= S3C64XX_SPI_PSR_MASK; + if (psr == S3C64XX_SPI_PSR_MASK) + psr--; + + speed = clk_get_rate(sdd->src_clk) / 2 / (psr + 1); + if (spi->max_speed_hz < speed) { + if (psr+1 < S3C64XX_SPI_PSR_MASK) { + psr++; + } else { + err = -EINVAL; + goto setup_exit; + } + } - speed = clk_get_rate(sdd->src_clk) / 2 / (psr + 1); - if (spi->max_speed_hz < speed) { - if (psr+1 < S3C64XX_SPI_PSR_MASK) { - psr++; - } else { + speed = clk_get_rate(sdd->src_clk) / 2 / (psr + 1); + if (spi->max_speed_hz >= speed) + spi->max_speed_hz = speed; + else err = -EINVAL; - goto setup_exit; - } } - speed = clk_get_rate(sdd->src_clk) / 2 / (psr + 1); - if (spi->max_speed_hz >= speed) - spi->max_speed_hz = speed; - else - err = -EINVAL; - setup_exit: /* setup() returns with device de-selected */ @@ -896,7 +913,8 @@ static void s3c64xx_spi_hwinit(struct s3c64xx_spi_driver_data *sdd, int channel) /* Disable Interrupts - we use Polling if not DMA mode */ writel(0, regs + S3C64XX_SPI_INT_EN); - writel(sci->src_clk_nr << S3C64XX_SPI_CLKSEL_SRCSHFT, + if (!sci->clk_from_cmu) + writel(sci->src_clk_nr << S3C64XX_SPI_CLKSEL_SRCSHFT, regs + S3C64XX_SPI_CLK_CFG); writel(0, regs + S3C64XX_SPI_MODE_CFG); writel(0, regs + S3C64XX_SPI_PACKET_CNT); -- 2.20.1