Message ID | 20200928181639.68415-1-ghilliar@amazon.com |
---|---|
State | Superseded |
Delegated to: | Stefan Roese |
Headers | show |
Series | spi: mvebu_a3700_spi: add support for cs-gpios | expand |
On 28.09.20 20:16, George Hilliard wrote: > 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> > --- > drivers/spi/mvebu_a3700_spi.c | 50 ++++++++++++++++++++++++++++++----- > 1 file changed, 44 insertions(+), 6 deletions(-) > > diff --git a/drivers/spi/mvebu_a3700_spi.c b/drivers/spi/mvebu_a3700_spi.c > index e860b9ec64..95be590a68 100644 > --- a/drivers/spi/mvebu_a3700_spi.c > +++ b/drivers/spi/mvebu_a3700_spi.c > @@ -15,6 +15,9 @@ > #include <asm/io.h> > #include <dm/device_compat.h> > #include <linux/bitops.h> > +#if CONFIG_IS_ENABLED(DM_GPIO) > +#include <asm/gpio.h> > +#endif To not add more #ifdef's, perhaps its better to include the header unconditionally here... > > DECLARE_GLOBAL_DATA_PTR; > > @@ -27,6 +30,7 @@ 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 +43,29 @@ struct spi_reg { > struct mvebu_spi_platdata { > struct spi_reg *spireg; > struct clk clk; > +#if CONFIG_IS_ENABLED(DM_GPIO) > + struct gpio_desc cs_gpios[MAX_CS_COUNT]; > +#endif ...and this variable in the struct as well... > }; > > -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) > + if (dm_gpio_is_valid(&plat->cs_gpios[cs])) > + dm_gpio_set_value(&plat->cs_gpios[cs], 1); > + else > +#endif > + setbits_le32(&plat->spireg->ctrl, MVEBU_SPI_A3700_SPI_EN_0 << cs); ... and use this instead here (and below): 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); What do you think? Thanks, Stefan > } > > -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) > + if (dm_gpio_is_valid(&plat->cs_gpios[cs])) > + dm_gpio_set_value(&plat->cs_gpios[cs], 0); > + else > +#endif > + clrbits_le32(&plat->spireg->ctrl, MVEBU_SPI_A3700_SPI_EN_0 << cs); > } > > /** > @@ -150,7 +167,7 @@ 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 +186,7 @@ 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 +264,27 @@ 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) > + if (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; > + } > + } > + } > +#endif > + > return 0; > } > > Viele Grüße, Stefan
diff --git a/drivers/spi/mvebu_a3700_spi.c b/drivers/spi/mvebu_a3700_spi.c index e860b9ec64..95be590a68 100644 --- a/drivers/spi/mvebu_a3700_spi.c +++ b/drivers/spi/mvebu_a3700_spi.c @@ -15,6 +15,9 @@ #include <asm/io.h> #include <dm/device_compat.h> #include <linux/bitops.h> +#if CONFIG_IS_ENABLED(DM_GPIO) +#include <asm/gpio.h> +#endif DECLARE_GLOBAL_DATA_PTR; @@ -27,6 +30,7 @@ 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 +43,29 @@ struct spi_reg { struct mvebu_spi_platdata { struct spi_reg *spireg; struct clk clk; +#if CONFIG_IS_ENABLED(DM_GPIO) + struct gpio_desc cs_gpios[MAX_CS_COUNT]; +#endif }; -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) + if (dm_gpio_is_valid(&plat->cs_gpios[cs])) + dm_gpio_set_value(&plat->cs_gpios[cs], 1); + else +#endif + 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) + if (dm_gpio_is_valid(&plat->cs_gpios[cs])) + dm_gpio_set_value(&plat->cs_gpios[cs], 0); + else +#endif + clrbits_le32(&plat->spireg->ctrl, MVEBU_SPI_A3700_SPI_EN_0 << cs); } /** @@ -150,7 +167,7 @@ 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 +186,7 @@ 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 +264,27 @@ 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) + if (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; + } + } + } +#endif + return 0; }
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> --- drivers/spi/mvebu_a3700_spi.c | 50 ++++++++++++++++++++++++++++++----- 1 file changed, 44 insertions(+), 6 deletions(-)