From a88e34ea213e1bdbd9b2dfca1e1e5fa68b9649a0 Mon Sep 17 00:00:00 2001 From: Murali Karicheri Date: Fri, 1 Aug 2014 19:40:32 +0300 Subject: [PATCH] spi: davinci: add support to configure gpio cs through dt Currently driver supports only configuration of GPIO CS through platform data. This patch enhances the driver to configure GPIO CS through DT. Also update the DT binding documentation to reflect the availability of cs-gpios. Signed-off-by: Murali Karicheri Signed-off-by: Grygorii Strashko Signed-off-by: Mark Brown --- .../devicetree/bindings/spi/spi-davinci.txt | 9 ++- drivers/spi/spi-davinci.c | 64 ++++++++++++++++--- 2 files changed, 64 insertions(+), 9 deletions(-) diff --git a/Documentation/devicetree/bindings/spi/spi-davinci.txt b/Documentation/devicetree/bindings/spi/spi-davinci.txt index 6d0ac8d0ad9b..f80887bca0d6 100644 --- a/Documentation/devicetree/bindings/spi/spi-davinci.txt +++ b/Documentation/devicetree/bindings/spi/spi-davinci.txt @@ -8,7 +8,8 @@ Required properties: - "ti,dm6441-spi" for SPI used similar to that on DM644x SoC family - "ti,da830-spi" for SPI used similar to that on DA8xx SoC family - reg: Offset and length of SPI controller register space -- num-cs: Number of chip selects +- num-cs: Number of chip selects. This includes internal as well as + GPIO chip selects. - ti,davinci-spi-intr-line: interrupt line used to connect the SPI IP to the interrupt controller within the SoC. Possible values are 0 and 1. Manual says one of the two possible interrupt @@ -17,6 +18,12 @@ Required properties: - interrupts: interrupt number mapped to CPU. - clocks: spi clk phandle +Optional: +- cs-gpios: gpio chip selects + For example to have 3 internal CS and 2 GPIO CS, user could define + cs-gpios = <0>, <0>, <0>, <&gpio1 30 0>, <&gpio1 31 0>; + where first three are internal CS and last two are GPIO CS. + Example of a NOR flash slave device (n25q032) connected to DaVinci SPI controller device over the SPI bus. diff --git a/drivers/spi/spi-davinci.c b/drivers/spi/spi-davinci.c index 2477af4bc1c7..ac4414e00bb9 100644 --- a/drivers/spi/spi-davinci.c +++ b/drivers/spi/spi-davinci.c @@ -30,6 +30,7 @@ #include #include #include +#include #include #include #include @@ -207,17 +208,28 @@ static inline void clear_io_bits(void __iomem *addr, u32 bits) static void davinci_spi_chipselect(struct spi_device *spi, int value) { struct davinci_spi *dspi; + struct device_node *np = spi->dev.of_node; struct davinci_spi_platform_data *pdata; + struct spi_master *master = spi->master; u8 chip_sel = spi->chip_select; u16 spidat1 = CS_DEFAULT; bool gpio_chipsel = false; + int gpio; dspi = spi_master_get_devdata(spi->master); pdata = &dspi->pdata; - if (pdata->chip_sel && chip_sel < pdata->num_chipselect && - pdata->chip_sel[chip_sel] != SPI_INTERN_CS) + if (np && master->cs_gpios != NULL && spi->cs_gpio >= 0) { + /* SPI core parse and update master->cs_gpio */ gpio_chipsel = true; + gpio = spi->cs_gpio; + } else if (pdata->chip_sel && + chip_sel < pdata->num_chipselect && + pdata->chip_sel[chip_sel] != SPI_INTERN_CS) { + /* platform data defines chip_sel */ + gpio_chipsel = true; + gpio = pdata->chip_sel[chip_sel]; + } /* * Board specific chip select logic decides the polarity and cs @@ -225,9 +237,9 @@ static void davinci_spi_chipselect(struct spi_device *spi, int value) */ if (gpio_chipsel) { if (value == BITBANG_CS_ACTIVE) - gpio_set_value(pdata->chip_sel[chip_sel], 0); + gpio_set_value(gpio, 0); else - gpio_set_value(pdata->chip_sel[chip_sel], 1); + gpio_set_value(gpio, 1); } else { if (value == BITBANG_CS_ACTIVE) { spidat1 |= SPIDAT1_CSHOLD_MASK; @@ -390,17 +402,41 @@ static int davinci_spi_setup(struct spi_device *spi) int retval = 0; struct davinci_spi *dspi; struct davinci_spi_platform_data *pdata; + struct spi_master *master = spi->master; + struct device_node *np = spi->dev.of_node; + bool internal_cs = true; dspi = spi_master_get_devdata(spi->master); pdata = &dspi->pdata; if (!(spi->mode & SPI_NO_CS)) { - if ((pdata->chip_sel == NULL) || - (pdata->chip_sel[spi->chip_select] == SPI_INTERN_CS)) - set_io_bits(dspi->base + SPIPC0, 1 << spi->chip_select); - + if (np && (master->cs_gpios != NULL) && (spi->cs_gpio >= 0)) { + unsigned long flags; + + flags = GPIOF_DIR_OUT; + if (spi->mode & SPI_CS_HIGH) + flags |= GPIOF_INIT_LOW; + else + flags |= GPIOF_INIT_HIGH; + retval = gpio_request_one(spi->cs_gpio, + flags, dev_name(&spi->dev)); + if (retval) { + dev_err(&spi->dev, + "GPIO %d request failed (%d)\n", + spi->cs_gpio, retval); + return retval; + } + internal_cs = false; + } else if (pdata->chip_sel && + spi->chip_select < pdata->num_chipselect && + pdata->chip_sel[spi->chip_select] != SPI_INTERN_CS) { + internal_cs = false; + } } + if (internal_cs) + set_io_bits(dspi->base + SPIPC0, 1 << spi->chip_select); + if (spi->mode & SPI_READY) set_io_bits(dspi->base + SPIPC0, SPIPC0_SPIENA_MASK); @@ -412,6 +448,15 @@ static int davinci_spi_setup(struct spi_device *spi) return retval; } +static void davinci_spi_cleanup(struct spi_device *spi) +{ + struct spi_master *master = spi->master; + struct device_node *np = spi->dev.of_node; + + if (np && (master->cs_gpios != NULL) && (spi->cs_gpio >= 0)) + gpio_free(spi->cs_gpio); +} + static int davinci_spi_check_error(struct davinci_spi *dspi, int int_status) { struct device *sdev = dspi->bitbang.master->dev.parent; @@ -810,6 +855,8 @@ static int spi_davinci_get_pdata(struct platform_device *pdev, /* * default num_cs is 1 and all chipsel are internal to the chip + * indicated by chip_sel being NULL or cs_gpios being NULL or + * set to -ENOENT. num-cs includes internal as well as gpios. * indicated by chip_sel being NULL. GPIO based CS is not * supported yet in DT bindings. */ @@ -921,6 +968,7 @@ static int davinci_spi_probe(struct platform_device *pdev) master->num_chipselect = pdata->num_chipselect; master->bits_per_word_mask = SPI_BPW_RANGE_MASK(2, 16); master->setup = davinci_spi_setup; + master->cleanup = davinci_spi_cleanup; dspi->bitbang.chipselect = davinci_spi_chipselect; dspi->bitbang.setup_transfer = davinci_spi_setup_transfer; -- 2.20.1