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Subject[PATCH v2 5/5] gpio: pca953x: add ->set_config implementation
Date
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>
---
drivers/gpio/gpio-pca953x.c | 66 +++++++++++++++++++++++++++++++++++--
1 file changed, 64 insertions(+), 2 deletions(-)

diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c
index 83d45f00e4d0..1e5579acd275 100644
--- a/drivers/gpio/gpio-pca953x.c
+++ b/drivers/gpio/gpio-pca953x.c
@@ -179,6 +179,8 @@ 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)

@@ -200,6 +202,8 @@ 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
*
@@ -248,7 +252,8 @@ 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;
}

@@ -269,7 +274,8 @@ 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);
}
@@ -474,6 +480,61 @@ static void pca953x_gpio_set_multiple(struct gpio_chip *gc,
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;
@@ -486,6 +547,7 @@ 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;
--
2.20.1
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