diff options
author | George Hilliard <ghilliar@amazon.com> | 2020-09-30 17:28:21 +0300 |
---|---|---|
committer | Stefan Roese <sr@denx.de> | 2020-10-14 08:55:56 +0300 |
commit | 2df286390a8009238ab9ccf5694ac088f3f90da3 (patch) | |
tree | 98fdd96ea2feeb61751c3105c22d3c6c70e84d28 /drivers/spi/mvebu_a3700_spi.c | |
parent | 87c220d0419a6073bd20184cbb81e15214affda0 (diff) | |
download | u-boot-2df286390a8009238ab9ccf5694ac088f3f90da3.tar.xz |
spi: mvebu_a3700_spi: add support for cs-gpios
The device tree has a way to specify GPIO lines as chip selects. From
the binding docs:
So if for example the controller has 2 CS lines, and the cs-gpios
property looks like this:
cs-gpios = <&gpio1 0 0> <0> <&gpio1 1 0> <&gpio1 2 0>;
Then it should be configured so that num_chipselect = 4 with the
following mapping:
cs0 : &gpio1 0 0
cs1 : native
cs2 : &gpio1 1 0
cs3 : &gpio1 2 0
Add support for this, while retaining backward-compatibility with
existing device trees; the driver will preserve existing behavior if a
cs-gpios list is not given, or if a particular line is specified as <0>
(native).
This implementation is inspired by similar implementations in
neighboring drivers for other platforms: atmega, mxc, etc.
Signed-off-by: George Hilliard <ghilliar@amazon.com>
Reviewed-by: Stefan Roese <sr@denx.de>
Diffstat (limited to 'drivers/spi/mvebu_a3700_spi.c')
-rw-r--r-- | drivers/spi/mvebu_a3700_spi.c | 41 |
1 files changed, 35 insertions, 6 deletions
diff --git a/drivers/spi/mvebu_a3700_spi.c b/drivers/spi/mvebu_a3700_spi.c index e860b9ec64..eb13cf349e 100644 --- a/drivers/spi/mvebu_a3700_spi.c +++ b/drivers/spi/mvebu_a3700_spi.c @@ -15,6 +15,7 @@ #include <asm/io.h> #include <dm/device_compat.h> #include <linux/bitops.h> +#include <asm/gpio.h> DECLARE_GLOBAL_DATA_PTR; @@ -27,6 +28,7 @@ DECLARE_GLOBAL_DATA_PTR; #define MVEBU_SPI_A3700_SPI_EN_0 BIT(16) #define MVEBU_SPI_A3700_CLK_PRESCALE_MASK 0x1f +#define MAX_CS_COUNT 4 /* SPI registers */ struct spi_reg { @@ -39,16 +41,23 @@ struct spi_reg { struct mvebu_spi_platdata { struct spi_reg *spireg; struct clk clk; + struct gpio_desc cs_gpios[MAX_CS_COUNT]; }; -static void spi_cs_activate(struct spi_reg *reg, int cs) +static void spi_cs_activate(struct mvebu_spi_platdata *plat, int cs) { - setbits_le32(®->ctrl, MVEBU_SPI_A3700_SPI_EN_0 << cs); + if (CONFIG_IS_ENABLED(DM_GPIO) && dm_gpio_is_valid(&plat->cs_gpios[cs])) + dm_gpio_set_value(&plat->cs_gpios[cs], 1); + else + setbits_le32(&plat->spireg->ctrl, MVEBU_SPI_A3700_SPI_EN_0 << cs); } -static void spi_cs_deactivate(struct spi_reg *reg, int cs) +static void spi_cs_deactivate(struct mvebu_spi_platdata *plat, int cs) { - clrbits_le32(®->ctrl, MVEBU_SPI_A3700_SPI_EN_0 << cs); + if (CONFIG_IS_ENABLED(DM_GPIO) && dm_gpio_is_valid(&plat->cs_gpios[cs])) + dm_gpio_set_value(&plat->cs_gpios[cs], 0); + else + clrbits_le32(&plat->spireg->ctrl, MVEBU_SPI_A3700_SPI_EN_0 << cs); } /** @@ -150,7 +159,7 @@ static int mvebu_spi_xfer(struct udevice *dev, unsigned int bitlen, /* Activate CS */ if (flags & SPI_XFER_BEGIN) { debug("SPI: activate cs.\n"); - spi_cs_activate(reg, spi_chip_select(dev)); + spi_cs_activate(plat, spi_chip_select(dev)); } /* Send and/or receive */ @@ -169,7 +178,7 @@ static int mvebu_spi_xfer(struct udevice *dev, unsigned int bitlen, return ret; debug("SPI: deactivate cs.\n"); - spi_cs_deactivate(reg, spi_chip_select(dev)); + spi_cs_deactivate(plat, spi_chip_select(dev)); } return 0; @@ -247,6 +256,26 @@ static int mvebu_spi_probe(struct udevice *bus) writel(data, ®->cfg); + /* Set up CS GPIOs in device tree, if any */ + if (CONFIG_IS_ENABLED(DM_GPIO) && gpio_get_list_count(bus, "cs-gpios") > 0) { + int i; + + for (i = 0; i < ARRAY_SIZE(plat->cs_gpios); i++) { + ret = gpio_request_by_name(bus, "cs-gpios", i, &plat->cs_gpios[i], 0); + if (ret < 0 || !dm_gpio_is_valid(&plat->cs_gpios[i])) { + /* Use the native CS function for this line */ + continue; + } + + ret = dm_gpio_set_dir_flags(&plat->cs_gpios[i], + GPIOD_IS_OUT | GPIOD_ACTIVE_LOW); + if (ret) { + dev_err(bus, "Setting cs %d error\n", i); + return ret; + } + } + } + return 0; } |