pinctrl: at91: add slewrate support for SAM9X60

Add slew rate support for SAM9X60 pin controller.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

3 files changed, 53 insertions, 0 deletions

diff --git a/drivers/pinctrl/pinctrl-at91.c b/drivers/pinctrl/pinctrl-at91.c
index 128003597f43..cb7c432769a5 100644
--- a/drivers/pinctrl/pinctrl-at91.c
+++ b/drivers/pinctrl/pinctrl-at91.c
@@ -59,6 +59,9 @@ static int gpio_banks;
 #define OUTPUT          (1 << 7)
 #define OUTPUT_VAL_SHIFT        8
 #define OUTPUT_VAL      (0x1 << OUTPUT_VAL_SHIFT)
+#define SLEWRATE_SHIFT  9
+#define SLEWRATE_MASK   0x1
+#define SLEWRATE        (SLEWRATE_MASK << SLEWRATE_SHIFT)
 #define DEBOUNCE        (1 << 16)
 #define DEBOUNCE_VAL_SHIFT      17
 #define DEBOUNCE_VAL    (0x3fff << DEBOUNCE_VAL_SHIFT)
@@ -82,6 +85,13 @@ enum drive_strength_bit {
 #define DRIVE_STRENGTH_BIT_MSK(name)    (DRIVE_STRENGTH_BIT_##name << \
                                          DRIVE_STRENGTH_SHIFT)
 
+enum slewrate_bit {
+        SLEWRATE_BIT_DIS,
+        SLEWRATE_BIT_ENA,
+};
+
+#define SLEWRATE_BIT_MSK(name)          (SLEWRATE_BIT_##name << SLEWRATE_SHIFT)
+
 /**
  * struct at91_pmx_func - describes AT91 pinmux functions
  * @name: the name of this specific function
@@ -171,6 +181,8 @@ struct at91_pinctrl_mux_ops {
         unsigned (*get_drivestrength)(void __iomem *pio, unsigned pin);
         void (*set_drivestrength)(void __iomem *pio, unsigned pin,
                                         u32 strength);
+        unsigned (*get_slewrate)(void __iomem *pio, unsigned pin);
+        void (*set_slewrate)(void __iomem *pio, unsigned pin, u32 slewrate);
         /* irq */
         int (*irq_type)(struct irq_data *d, unsigned type);
 };
@@ -585,6 +597,16 @@ static unsigned at91_mux_sam9x60_get_drivestrength(void __iomem *pio,
         return DRIVE_STRENGTH_BIT_LOW;
 }
 
+static unsigned at91_mux_sam9x60_get_slewrate(void __iomem *pio, unsigned pin)
+{
+        unsigned tmp = readl_relaxed(pio + SAM9X60_PIO_SLEWR);
+
+        if ((tmp & BIT(pin)))
+                return SLEWRATE_BIT_ENA;
+
+        return SLEWRATE_BIT_DIS;
+}
+
 static void set_drive_strength(void __iomem *reg, unsigned pin, u32 strength)
 {
         unsigned tmp = readl_relaxed(reg);
@@ -643,6 +665,24 @@ static void at91_mux_sam9x60_set_drivestrength(void __iomem *pio, unsigned pin,
         writel_relaxed(tmp, pio + SAM9X60_PIO_DRIVER1);
 }
 
+static void at91_mux_sam9x60_set_slewrate(void __iomem *pio, unsigned pin,
+                                          u32 setting)
+{
+        unsigned int tmp;
+
+        if (setting < SLEWRATE_BIT_DIS || setting > SLEWRATE_BIT_ENA)
+                return;
+
+        tmp = readl_relaxed(pio + SAM9X60_PIO_SLEWR);
+
+        if (setting == SLEWRATE_BIT_DIS)
+                tmp &= ~BIT(pin);
+        else
+                tmp |= BIT(pin);
+
+        writel_relaxed(tmp, pio + SAM9X60_PIO_SLEWR);
+}
+
 static struct at91_pinctrl_mux_ops at91rm9200_ops = {
         .get_periph     = at91_mux_get_periph,
         .mux_A_periph   = at91_mux_set_A_periph,
@@ -687,6 +727,8 @@ static const struct at91_pinctrl_mux_ops sam9x60_ops = {
         .disable_schmitt_trig = at91_mux_pio3_disable_schmitt_trig,
         .get_drivestrength = at91_mux_sam9x60_get_drivestrength,
         .set_drivestrength = at91_mux_sam9x60_set_drivestrength,
+        .get_slewrate   = at91_mux_sam9x60_get_slewrate,
+        .set_slewrate   = at91_mux_sam9x60_set_slewrate,
         .irq_type       = alt_gpio_irq_type,
 
 };
@@ -950,6 +992,8 @@ static int at91_pinconf_get(struct pinctrl_dev *pctldev,
         if (info->ops->get_drivestrength)
                 *config |= (info->ops->get_drivestrength(pio, pin)
                                 << DRIVE_STRENGTH_SHIFT);
+        if (info->ops->get_slewrate)
+                *config |= (info->ops->get_slewrate(pio, pin) << SLEWRATE_SHIFT);
         if (at91_mux_get_output(pio, pin, &out))
                 *config |= OUTPUT | (out << OUTPUT_VAL_SHIFT);
 
@@ -1001,6 +1045,9 @@ static int at91_pinconf_set(struct pinctrl_dev *pctldev,
                         info->ops->set_drivestrength(pio, pin,
                                 (config & DRIVE_STRENGTH)
                                         >> DRIVE_STRENGTH_SHIFT);
+                if (info->ops->set_slewrate)
+                        info->ops->set_slewrate(pio, pin,
+                                (config & SLEWRATE) >> SLEWRATE_SHIFT);
 
         } /* for each config */
 
@@ -1044,6 +1091,7 @@ static void at91_pinconf_dbg_show(struct pinctrl_dev *pctldev,
                              DRIVE_STRENGTH_MED);
         DBG_SHOW_FLAG_MASKED(DRIVE_STRENGTH, DRIVE_STRENGTH_BIT_MSK(HI),
                              DRIVE_STRENGTH_HI);
+        DBG_SHOW_FLAG(SLEWRATE);
         DBG_SHOW_FLAG(DEBOUNCE);
         if (config & DEBOUNCE) {
                 val = config >> DEBOUNCE_VAL_SHIFT;
diff --git a/drivers/pinctrl/pinctrl-at91.h b/drivers/pinctrl/pinctrl-at91.h
index 19fc27e66bfd..223620f14b05 100644
--- a/drivers/pinctrl/pinctrl-at91.h
+++ b/drivers/pinctrl/pinctrl-at91.h
@@ -69,6 +69,7 @@
 #define AT91SAM9X5_PIO_DRIVER1  0x114  /*PIO Driver 1 register offset*/
 #define AT91SAM9X5_PIO_DRIVER2  0x118  /*PIO Driver 2 register offset*/
 
+#define SAM9X60_PIO_SLEWR       0x110   /* PIO Slew Rate Control Register */
 #define SAM9X60_PIO_DRIVER1     0x118   /* PIO Driver 1 register offset */
 
 #endif
diff --git a/include/dt-bindings/pinctrl/at91.h b/include/dt-bindings/pinctrl/at91.h
index eb81867eac77..8dc10e00c627 100644
--- a/include/dt-bindings/pinctrl/at91.h
+++ b/include/dt-bindings/pinctrl/at91.h
@@ -17,6 +17,7 @@
 #define AT91_PINCTRL_DIS_SCHMIT         (1 << 4)
 #define AT91_PINCTRL_OUTPUT             (1 << 7)
 #define AT91_PINCTRL_OUTPUT_VAL(x)      ((x & 0x1) << 8)
+#define AT91_PINCTRL_SLEWRATE           (1 << 9)
 #define AT91_PINCTRL_DEBOUNCE           (1 << 16)
 #define AT91_PINCTRL_DEBOUNCE_VAL(x)    (x << 17)
 
@@ -27,6 +28,9 @@
 #define AT91_PINCTRL_DRIVE_STRENGTH_MED                 (0x2 << 5)
 #define AT91_PINCTRL_DRIVE_STRENGTH_HI                  (0x3 << 5)
 
+#define AT91_PINCTRL_SLEWRATE_DIS       (0x0 << 9)
+#define AT91_PINCTRL_SLEWRATE_ENA       (0x1 << 9)
+
 #define AT91_PIOA       0
 #define AT91_PIOB       1
 #define AT91_PIOC       2