* [PATCH] spi: mvebu_a3700_spi: add support for cs-gpios
@ 2020-09-28 18:16 George Hilliard
2020-09-29 5:28 ` Stefan Roese
0 siblings, 1 reply; 2+ messages in thread
From: George Hilliard @ 2020-09-28 18:16 UTC (permalink / raw)
To: u-boot
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
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;
}
--
2.23.3
^ permalink raw reply related [flat|nested] 2+ messages in thread
* [PATCH] spi: mvebu_a3700_spi: add support for cs-gpios
2020-09-28 18:16 [PATCH] spi: mvebu_a3700_spi: add support for cs-gpios George Hilliard
@ 2020-09-29 5:28 ` Stefan Roese
0 siblings, 0 replies; 2+ messages in thread
From: Stefan Roese @ 2020-09-29 5:28 UTC (permalink / raw)
To: u-boot
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 Gr??e,
Stefan
--
DENX Software Engineering GmbH, Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-51 Fax: (+49)-8142-66989-80 Email: sr at denx.de
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2020-09-28 18:16 [PATCH] spi: mvebu_a3700_spi: add support for cs-gpios George Hilliard
2020-09-29 5:28 ` Stefan Roese
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