drivers: gpio: pca95xx: Reduce data transfer over I2C
When accessing GPIO by pin, access only the required port register
(instead of systematically accessing both PORT0 and PORT1).
Signed-off-by: Vincent Geneves <vgeneves@kalray.eu>
diff --git a/drivers/gpio/gpio_pca95xx.c b/drivers/gpio/gpio_pca95xx.c
index 3baccc4..5330b01 100644
--- a/drivers/gpio/gpio_pca95xx.c
+++ b/drivers/gpio/gpio_pca95xx.c
@@ -28,6 +28,14 @@
#include <zephyr/logging/log.h>
LOG_MODULE_REGISTER(gpio_pca95xx);
+#if CONFIG_LITTLE_ENDIAN
+#define LOW_BYTE_LE16_IDX 0
+#define HIGH_BYTE_LE16_IDX 1
+#else
+#define LOW_BYTE_LE16_IDX 1
+#define HIGH_BYTE_LE16_IDX 0
+#endif
+
/* Register definitions */
#define REG_INPUT_PORT0 0x00
#define REG_INPUT_PORT1 0x01
@@ -36,7 +44,7 @@
#define REG_POL_INV_PORT0 0x04
#define REG_POL_INV_PORT1 0x05
#define REG_CONF_PORT0 0x06
-#define REG_CONG_PORT1 0x07
+#define REG_CONF_PORT1 0x07
#define REG_OUT_DRV_STRENGTH_PORT0_L 0x40
#define REG_OUT_DRV_STRENGTH_PORT0_H 0x41
#define REG_OUT_DRV_STRENGTH_PORT1_L 0x42
@@ -108,6 +116,37 @@
#endif
};
+static int read_port_reg(const struct device *dev, uint8_t reg, uint8_t pin,
+ uint16_t *cache, uint16_t *buf)
+{
+ const struct gpio_pca95xx_config * const config = dev->config;
+ uint8_t b_buf;
+ int ret;
+
+ if (pin >= 8)
+ reg++;
+
+ ret = i2c_reg_read_byte_dt(&config->bus, reg, &b_buf);
+ if (ret != 0) {
+ LOG_ERR("PCA95XX[0x%X]: error reading register 0x%X (%d)",
+ config->bus.addr, reg, ret);
+ return ret;
+ }
+
+ if (pin < 8) {
+ ((uint8_t *)cache)[LOW_BYTE_LE16_IDX] = b_buf;
+ } else {
+ ((uint8_t *)cache)[HIGH_BYTE_LE16_IDX] = b_buf;
+ }
+
+ *buf = *cache;
+
+ LOG_DBG("PCA95XX[0x%X]: Read: REG[0x%X] = 0x%X",
+ config->bus.addr, reg, b_buf);
+
+ return 0;
+}
+
/**
* @brief Read both port 0 and port 1 registers of certain register function.
*
@@ -145,6 +184,36 @@
return 0;
}
+
+static int write_port_reg(const struct device *dev, uint8_t reg, uint8_t pin,
+ uint16_t *cache, uint16_t value)
+{
+ const struct gpio_pca95xx_config * const config = dev->config;
+ uint8_t buf[2];
+ int ret;
+
+ if (pin < 8) {
+ buf[1] = value;
+ } else {
+ buf[1] = value >> 8;
+ reg++;
+ }
+ buf[0] = reg;
+
+ LOG_DBG("PCA95XX[0x%X]: Write: REG[0x%X] = 0x%X", config->bus.addr,
+ reg, buf[1]);
+
+ ret = i2c_write_dt(&config->bus, buf, sizeof(buf));
+ if (ret == 0) {
+ *cache = value;
+ } else {
+ LOG_ERR("PCA95XX[0x%X]: error writing to register 0x%X "
+ "(%d)", config->bus.addr, reg, ret);
+ }
+
+ return ret;
+}
+
/**
* @brief Write both port 0 and port 1 registers of certain register function.
*
@@ -182,6 +251,16 @@
return ret;
}
+static inline int update_input_reg(const struct device *dev, uint8_t pin,
+ uint16_t *buf)
+{
+ struct gpio_pca95xx_drv_data * const drv_data =
+ (struct gpio_pca95xx_drv_data * const)dev->data;
+
+ return read_port_reg(dev, REG_INPUT_PORT0, pin,
+ &drv_data->reg_cache.input, buf);
+}
+
static inline int update_input_regs(const struct device *dev, uint16_t *buf)
{
struct gpio_pca95xx_drv_data * const drv_data =
@@ -191,6 +270,16 @@
&drv_data->reg_cache.input, buf);
}
+static inline int update_output_reg(const struct device *dev, uint8_t pin,
+ uint16_t value)
+{
+ struct gpio_pca95xx_drv_data * const drv_data =
+ (struct gpio_pca95xx_drv_data * const)dev->data;
+
+ return write_port_reg(dev, REG_OUTPUT_PORT0, pin,
+ &drv_data->reg_cache.output, value);
+}
+
static inline int update_output_regs(const struct device *dev, uint16_t value)
{
struct gpio_pca95xx_drv_data * const drv_data =
@@ -200,43 +289,45 @@
&drv_data->reg_cache.output, value);
}
-static inline int update_direction_regs(const struct device *dev,
+static inline int update_direction_reg(const struct device *dev, uint8_t pin,
uint16_t value)
{
struct gpio_pca95xx_drv_data * const drv_data =
(struct gpio_pca95xx_drv_data * const)dev->data;
- return write_port_regs(dev, REG_CONF_PORT0,
- &drv_data->reg_cache.dir, value);
+ return write_port_reg(dev, REG_CONF_PORT0, pin,
+ &drv_data->reg_cache.dir, value);
}
-static inline int update_pul_sel_regs(const struct device *dev,
- uint16_t value)
+static inline int update_pul_sel_reg(const struct device *dev, uint8_t pin,
+ uint16_t value)
{
struct gpio_pca95xx_drv_data * const drv_data =
(struct gpio_pca95xx_drv_data * const)dev->data;
- return write_port_regs(dev, REG_PUD_SEL_PORT0,
- &drv_data->reg_cache.pud_sel, value);
+ return write_port_reg(dev, REG_PUD_SEL_PORT0, pin,
+ &drv_data->reg_cache.pud_sel, value);
}
-static inline int update_pul_en_regs(const struct device *dev, uint16_t value)
+static inline int update_pul_en_reg(const struct device *dev, uint8_t pin,
+ uint8_t value)
{
struct gpio_pca95xx_drv_data * const drv_data =
(struct gpio_pca95xx_drv_data * const)dev->data;
- return write_port_regs(dev, REG_PUD_EN_PORT0,
- &drv_data->reg_cache.pud_en, value);
+ return write_port_reg(dev, REG_PUD_EN_PORT0, pin,
+ &drv_data->reg_cache.pud_en, value);
}
#ifdef CONFIG_GPIO_PCA95XX_INTERRUPT
-static inline int update_int_mask_regs(const struct device *dev, uint16_t value)
+static inline int update_int_mask_reg(const struct device *dev, uint8_t pin,
+ uint16_t value)
{
struct gpio_pca95xx_drv_data * const drv_data =
(struct gpio_pca95xx_drv_data * const)dev->data;
- return write_port_regs(dev, REG_INT_MASK_PORT0,
- &drv_data->reg_cache.int_mask, value);
+ return write_port_reg(dev, REG_INT_MASK_PORT0, pin,
+ &drv_data->reg_cache.int_mask, value);
}
#endif /* CONFIG_GPIO_PCA95XX_INTERRUPT */
@@ -264,7 +355,7 @@
} else if ((flags & GPIO_OUTPUT_INIT_LOW) != 0U) {
reg_out &= ~BIT(pin);
}
- ret = update_output_regs(dev, reg_out);
+ ret = update_output_reg(dev, pin, reg_out);
if (ret != 0) {
return ret;
}
@@ -273,7 +364,7 @@
reg_dir |= BIT(pin);
}
- ret = update_direction_regs(dev, reg_dir);
+ ret = update_direction_reg(dev, pin, reg_dir);
return ret;
}
@@ -319,7 +410,7 @@
/* pull down == 0, pull up == 1 */
WRITE_BIT(reg_pud, pin, (flags & GPIO_PULL_UP) != 0U);
- ret = update_pul_sel_regs(dev, reg_pud);
+ ret = update_pul_sel_reg(dev, pin, reg_pud);
if (ret) {
return ret;
}
@@ -331,7 +422,7 @@
WRITE_BIT(reg_pud, pin,
(flags & (GPIO_PULL_UP | GPIO_PULL_DOWN)) != 0U);
- ret = update_pul_en_regs(dev, reg_pud);
+ ret = update_pul_en_reg(dev, pin, reg_pud);
return ret;
}
@@ -394,8 +485,7 @@
return ret;
}
-static int gpio_pca95xx_port_get_raw(const struct device *dev,
- uint32_t *value)
+static int gpio_pca95xx_port_get_raw(const struct device *dev, uint32_t *value)
{
struct gpio_pca95xx_drv_data * const drv_data =
(struct gpio_pca95xx_drv_data * const)dev->data;
@@ -587,7 +677,7 @@
reg_out = drv_data->reg_cache.int_mask;
WRITE_BIT(reg_out, pin, (mode == GPIO_INT_MODE_DISABLED));
- ret = update_int_mask_regs(dev, reg_out);
+ ret = update_int_mask_reg(dev, pin, reg_out);
if (ret != 0) {
LOG_ERR("PCA95XX[0x%X]: failed to update int mask (%d)",
config->bus.addr, ret);
