pinctrl: support pinconfig on the U300

This adds pin configuration support for the U300 driver pair,
we can now read out the biasing and drive mode in debugfs and
configure it using the new configuration API.

ChangeLog v1->v2:
- Migrate to pin config and generic pin config changes.
ChangeLog v2->v3:
- Adjust to generic pin config changes in v7 patch set.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 69 insertions, 8 deletions

diff --git a/drivers/pinctrl/pinctrl-coh901.c b/drivers/pinctrl/pinctrl-coh901.c
index 724234c9b01b..0797eba3e33a 100644
--- a/drivers/pinctrl/pinctrl-coh901.c
+++ b/drivers/pinctrl/pinctrl-coh901.c
@@ -23,7 +23,9 @@
 #include <linux/list.h>
 #include <linux/slab.h>
 #include <linux/pinctrl/consumer.h>
+#include <linux/pinctrl/pinconf-generic.h>
 #include <mach/gpio-u300.h>
+#include "pinctrl-coh901.h"
 
 /*
  * Register definitions for COH 901 335 variant
@@ -418,8 +420,68 @@ static int u300_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
         return retirq;
 }
 
-static int u300_gpio_config(struct gpio_chip *chip, unsigned offset,
-                            enum pin_config_param param, unsigned long data)
+/* Returning -EINVAL means "supported but not available" */
+int u300_gpio_config_get(struct gpio_chip *chip,
+                         unsigned offset,
+                         unsigned long *config)
+{
+        struct u300_gpio *gpio = to_u300_gpio(chip);
+        enum pin_config_param param = (enum pin_config_param) *config;
+        bool biasmode;
+        u32 drmode;
+
+        /* One bit per pin, clamp to bool range */
+        biasmode = !!(readl(U300_PIN_REG(offset, per)) & U300_PIN_BIT(offset));
+
+        /* Mask out the two bits for this pin and shift to bits 0,1 */
+        drmode = readl(U300_PIN_REG(offset, pcr));
+        drmode &= (U300_GPIO_PXPCR_PIN_MODE_MASK << ((offset & 0x07) << 1));
+        drmode >>= ((offset & 0x07) << 1);
+
+        switch(param) {
+        case PIN_CONFIG_BIAS_HIGH_IMPEDANCE:
+                *config = 0;
+                if (biasmode)
+                        return 0;
+                else
+                        return -EINVAL;
+                break;
+        case PIN_CONFIG_BIAS_PULL_UP:
+                *config = 0;
+                if (!biasmode)
+                        return 0;
+                else
+                        return -EINVAL;
+                break;
+        case PIN_CONFIG_DRIVE_PUSH_PULL:
+                *config = 0;
+                if (drmode == U300_GPIO_PXPCR_PIN_MODE_OUTPUT_PUSH_PULL)
+                        return 0;
+                else
+                        return -EINVAL;
+                break;
+        case PIN_CONFIG_DRIVE_OPEN_DRAIN:
+                *config = 0;
+                if (drmode == U300_GPIO_PXPCR_PIN_MODE_OUTPUT_OPEN_DRAIN)
+                        return 0;
+                else
+                        return -EINVAL;
+                break;
+        case PIN_CONFIG_DRIVE_OPEN_SOURCE:
+                *config = 0;
+                if (drmode == U300_GPIO_PXPCR_PIN_MODE_OUTPUT_OPEN_SOURCE)
+                        return 0;
+                else
+                        return -EINVAL;
+                break;
+        default:
+                break;
+        }
+        return -ENOTSUPP;
+}
+
+int u300_gpio_config_set(struct gpio_chip *chip, unsigned offset,
+                         enum pin_config_param param)
 {
         struct u300_gpio *gpio = to_u300_gpio(chip);
         unsigned long flags;
@@ -620,13 +682,12 @@ static void __init u300_gpio_init_pin(struct u300_gpio *gpio,
                 u300_gpio_direction_output(&gpio->chip, offset, conf->outval);
 
                 /* Deactivate bias mode for output */
-                u300_gpio_config(&gpio->chip, offset,
-                                 PIN_CONFIG_BIAS_HIGH_IMPEDANCE,
-                                 0);
+                u300_gpio_config_set(&gpio->chip, offset,
+                                     PIN_CONFIG_BIAS_HIGH_IMPEDANCE);
 
                 /* Set drive mode for output */
-                u300_gpio_config(&gpio->chip, offset,
-                                 PIN_CONFIG_DRIVE_PUSH_PULL, 0);
+                u300_gpio_config_set(&gpio->chip, offset,
+                                     PIN_CONFIG_DRIVE_PUSH_PULL);
 
                 dev_dbg(gpio->dev, "set up pin %d as output, value: %d\n",
                         offset, conf->outval);
@@ -637,7 +698,7 @@ static void __init u300_gpio_init_pin(struct u300_gpio *gpio,
                 u300_gpio_set(&gpio->chip, offset, 0);
 
                 /* Set bias mode for input */
-                u300_gpio_config(&gpio->chip, offset, conf->bias_mode, 0);
+                u300_gpio_config_set(&gpio->chip, offset, conf->bias_mode);
 
                 dev_dbg(gpio->dev, "set up pin %d as input, bias: %04x\n",
                         offset, conf->bias_mode);