[PATCH 4/4] pinctrl: at91-pio4: implement drive strength support

[Eugen Hristev <eugen.hristev@microchip.com>]

Implement drive strength support, by preserving the same bindings
as in Linux.

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
---
 arch/arm/mach-at91/include/mach/atmel_pio4.h | 1 +
 drivers/pinctrl/pinctrl-at91-pio4.c          | 8 ++++++++
 include/dt-bindings/pinctrl/at91.h           | 4 ++++
 3 files changed, 13 insertions(+)

diff --git a/arch/arm/mach-at91/include/mach/atmel_pio4.h b/arch/arm/mach-at91/include/mach/atmel_pio4.h
index f348b05bc8..35ac7b2d40 100644
--- a/arch/arm/mach-at91/include/mach/atmel_pio4.h
+++ b/arch/arm/mach-at91/include/mach/atmel_pio4.h
@@ -52,6 +52,7 @@ struct atmel_pio4_port {
 #define ATMEL_PIO_DRVSTR_LO		(1 << 16)
 #define ATMEL_PIO_DRVSTR_ME		(2 << 16)
 #define ATMEL_PIO_DRVSTR_HI		(3 << 16)
+#define ATMEL_PIO_DRVSTR_OFFSET		16
 #define ATMEL_PIO_CFGR_EVTSEL_MASK	GENMASK(26, 24)
 #define ATMEL_PIO_CFGR_EVTSEL_FALLING	(0 << 24)
 #define ATMEL_PIO_CFGR_EVTSEL_RISING	(1 << 24)
diff --git a/drivers/pinctrl/pinctrl-at91-pio4.c b/drivers/pinctrl/pinctrl-at91-pio4.c
index 58f4d8cb39..350ea0a1f3 100644
--- a/drivers/pinctrl/pinctrl-at91-pio4.c
+++ b/drivers/pinctrl/pinctrl-at91-pio4.c
@@ -34,6 +34,7 @@ static const struct pinconf_param conf_params[] = {
 	{ "input-schmitt-disable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 0 },
 	{ "input-schmitt-enable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 1 },
 	{ "input-debounce", PIN_CONFIG_INPUT_DEBOUNCE, 0 },
+	{ "atmel,drive-strength", PIN_CONFIG_DRIVE_STRENGTH, 0 },
 };
 
 static u32 atmel_pinctrl_get_pinconf(struct udevice *config)
@@ -41,6 +42,7 @@ static u32 atmel_pinctrl_get_pinconf(struct udevice *config)
 	const struct pinconf_param *params;
 	u32 param, arg, conf = 0;
 	u32 i;
+	u32 val;
 
 	for (i = 0; i < ARRAY_SIZE(conf_params); i++) {
 		params = &conf_params[i];
@@ -82,6 +84,12 @@ static u32 atmel_pinctrl_get_pinconf(struct udevice *config)
 				conf |= ATMEL_PIO_IFSCEN_MASK;
 			}
 			break;
+		case PIN_CONFIG_DRIVE_STRENGTH:
+			dev_read_u32(config, params->property, &val);
+			conf &= (~ATMEL_PIO_DRVSTR_MASK);
+			conf |= (val << ATMEL_PIO_DRVSTR_OFFSET)
+				& ATMEL_PIO_DRVSTR_MASK;
+			break;
 		default:
 			printf("%s: Unsupported configuration parameter: %u\n",
 			       __func__, param);
diff --git a/include/dt-bindings/pinctrl/at91.h b/include/dt-bindings/pinctrl/at91.h
index 5afb1863c3..3831f91fb3 100644
--- a/include/dt-bindings/pinctrl/at91.h
+++ b/include/dt-bindings/pinctrl/at91.h
@@ -42,4 +42,8 @@
 #define AT91_PERIPH_C		3
 #define AT91_PERIPH_D		4
 
+#define ATMEL_PIO_DRVSTR_LO	1
+#define ATMEL_PIO_DRVSTR_ME	2
+#define ATMEL_PIO_DRVSTR_HI	3
+
 #endif /* __DT_BINDINGS_AT91_PINCTRL_H__ */
-- 
2.25.1