gpio: pca953x: add ->set_config implementation

This commit adds a minimal implementation of the ->set_config() hook,
with support for the PIN_CONFIG_BIAS_PULL_UP and
PIN_CONFIG_BIAS_PULL_DOWN configurations.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c
index 83617fd..4cace44 100644 (file)
--- a/drivers/gpio/gpio-pca953x.c
+++ b/drivers/gpio/gpio-pca953x.c
@@ -178,6 +178,8 @@ static int pca953x_bank_shift(struct pca953x_chip *chip)
 #define PCA957x_BANK_OUTPUT    BIT(5)
 
 #define PCAL9xxx_BANK_IN_LATCH BIT(8 + 2)
+#define PCAL9xxx_BANK_PULL_EN  BIT(8 + 3)
+#define PCAL9xxx_BANK_PULL_SEL BIT(8 + 4)
 #define PCAL9xxx_BANK_IRQ_MASK BIT(8 + 5)
 #define PCAL9xxx_BANK_IRQ_STAT BIT(8 + 6)
 
@@ -199,6 +201,8 @@ static int pca953x_bank_shift(struct pca953x_chip *chip)
  * - Extended set, above 0x40, often chip specific.
  *   - PCAL6524/PCAL9555A with custom PCAL IRQ handling:
  *     Input latch register            0x40 + 2 * bank_size    RW
+ *     Pull-up/pull-down enable reg    0x40 + 3 * bank_size    RW
+ *     Pull-up/pull-down select reg    0x40 + 4 * bank_size    RW
  *     Interrupt mask register         0x40 + 5 * bank_size    RW
  *     Interrupt status register       0x40 + 6 * bank_size    R
  *
@@ -247,7 +251,8 @@ static bool pca953x_readable_register(struct device *dev, unsigned int reg)
        }
 
        if (chip->driver_data & PCA_PCAL) {
-               bank |= PCAL9xxx_BANK_IN_LATCH | PCAL9xxx_BANK_IRQ_MASK |
+               bank |= PCAL9xxx_BANK_IN_LATCH | PCAL9xxx_BANK_PULL_EN |
+                       PCAL9xxx_BANK_PULL_SEL | PCAL9xxx_BANK_IRQ_MASK |
                        PCAL9xxx_BANK_IRQ_STAT;
        }
 
@@ -268,7 +273,8 @@ static bool pca953x_writeable_register(struct device *dev, unsigned int reg)
        }
 
        if (chip->driver_data & PCA_PCAL)
-               bank |= PCAL9xxx_BANK_IN_LATCH | PCAL9xxx_BANK_IRQ_MASK;
+               bank |= PCAL9xxx_BANK_IN_LATCH | PCAL9xxx_BANK_PULL_EN |
+                       PCAL9xxx_BANK_PULL_SEL | PCAL9xxx_BANK_IRQ_MASK;
 
        return pca953x_check_register(chip, reg, bank);
 }
@@ -473,6 +479,61 @@ exit:
        mutex_unlock(&chip->i2c_lock);
 }
 
+static int pca953x_gpio_set_pull_up_down(struct pca953x_chip *chip,
+                                        unsigned int offset,
+                                        unsigned long config)
+{
+       u8 pull_en_reg = pca953x_recalc_addr(chip, PCAL953X_PULL_EN, offset,
+                                            true, false);
+       u8 pull_sel_reg = pca953x_recalc_addr(chip, PCAL953X_PULL_SEL, offset,
+                                             true, false);
+       u8 bit = BIT(offset % BANK_SZ);
+       int ret;
+
+       /*
+        * pull-up/pull-down configuration requires PCAL extended
+        * registers
+        */
+       if (!(chip->driver_data & PCA_PCAL))
+               return -ENOTSUPP;
+
+       mutex_lock(&chip->i2c_lock);
+
+       /* Disable pull-up/pull-down */
+       ret = regmap_write_bits(chip->regmap, pull_en_reg, bit, 0);
+       if (ret)
+               goto exit;
+
+       /* Configure pull-up/pull-down */
+       if (config == PIN_CONFIG_BIAS_PULL_UP)
+               ret = regmap_write_bits(chip->regmap, pull_sel_reg, bit, bit);
+       else if (config == PIN_CONFIG_BIAS_PULL_DOWN)
+               ret = regmap_write_bits(chip->regmap, pull_sel_reg, bit, 0);
+       if (ret)
+               goto exit;
+
+       /* Enable pull-up/pull-down */
+       ret = regmap_write_bits(chip->regmap, pull_en_reg, bit, bit);
+
+exit:
+       mutex_unlock(&chip->i2c_lock);
+       return ret;
+}
+
+static int pca953x_gpio_set_config(struct gpio_chip *gc, unsigned int offset,
+                                  unsigned long config)
+{
+       struct pca953x_chip *chip = gpiochip_get_data(gc);
+
+       switch (config) {
+       case PIN_CONFIG_BIAS_PULL_UP:
+       case PIN_CONFIG_BIAS_PULL_DOWN:
+               return pca953x_gpio_set_pull_up_down(chip, offset, config);
+       default:
+               return -ENOTSUPP;
+       }
+}
+
 static void pca953x_setup_gpio(struct pca953x_chip *chip, int gpios)
 {
        struct gpio_chip *gc;
@@ -485,6 +546,7 @@ static void pca953x_setup_gpio(struct pca953x_chip *chip, int gpios)
        gc->set = pca953x_gpio_set_value;
        gc->get_direction = pca953x_gpio_get_direction;
        gc->set_multiple = pca953x_gpio_set_multiple;
+       gc->set_config = pca953x_gpio_set_config;
        gc->can_sleep = true;
 
        gc->base = chip->gpio_start;