@@ -10,6 +10,7 @@
#include <linux/device.h>
#include <linux/dev_printk.h>
#include <linux/err.h>
+#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/i2c-of-prober.h>
#include <linux/module.h>
@@ -31,7 +32,6 @@
* address responds.
*
* TODO:
- * - Support handling common GPIOs.
* - Support I2C muxes
*/
@@ -246,6 +246,62 @@ static void i2c_of_probe_simple_disable_regulator(struct device *dev, struct i2c
regulator_disable(ctx->supply);
}
+static int i2c_of_probe_simple_get_gpiod(struct device *dev, struct device_node *node,
+ struct i2c_of_probe_simple_ctx *ctx)
+{
+ struct fwnode_handle *fwnode = of_fwnode_handle(node);
+ struct gpio_desc *gpiod;
+ const char *con_id;
+
+ /* NULL signals no GPIO needed */
+ if (!ctx->opts->gpio_name)
+ return 0;
+
+ /* An empty string signals an unnamed GPIO */
+ if (!ctx->opts->gpio_name[0])
+ con_id = NULL;
+ else
+ con_id = ctx->opts->gpio_name;
+
+ gpiod = fwnode_gpiod_get_index(fwnode, con_id, 0, GPIOD_ASIS, "i2c-of-prober");
+ if (IS_ERR(gpiod))
+ return PTR_ERR(gpiod);
+
+ ctx->gpiod = gpiod;
+
+ return 0;
+}
+
+static void i2c_of_probe_simple_put_gpiod(struct i2c_of_probe_simple_ctx *ctx)
+{
+ gpiod_put(ctx->gpiod);
+ ctx->gpiod = NULL;
+}
+
+static int i2c_of_probe_simple_set_gpio(struct device *dev, struct i2c_of_probe_simple_ctx *ctx)
+{
+ int ret;
+
+ if (!ctx->gpiod)
+ return 0;
+
+ dev_dbg(dev, "Configuring GPIO\n");
+
+ ret = gpiod_direction_output(ctx->gpiod, ctx->opts->gpio_assert_to_enable);
+ if (ret)
+ return ret;
+
+ if (ctx->opts->post_gpio_config_delay_ms)
+ msleep(ctx->opts->post_gpio_config_delay_ms);
+
+ return 0;
+}
+
+static void i2c_of_probe_simple_disable_gpio(struct device *dev, struct i2c_of_probe_simple_ctx *ctx)
+{
+ gpiod_set_value(ctx->gpiod, !ctx->opts->gpio_assert_to_enable);
+}
+
/**
* i2c_of_probe_simple_enable - Simple helper for I2C OF prober to get and enable resources
* @dev: Pointer to the &struct device of the caller, only used for dev_printk() messages
@@ -253,7 +309,11 @@ static void i2c_of_probe_simple_disable_regulator(struct device *dev, struct i2c
* @data: Pointer to &struct i2c_of_probe_simple_ctx helper context.
*
* If &i2c_of_probe_simple_opts->supply_name is given, request the named regulator supply.
+ * If &i2c_of_probe_simple_opts->gpio_name is given, request the named GPIO. Or if it is
+ * the empty string, request the unnamed GPIO.
* If a regulator supply was found, enable that regulator.
+ * If a GPIO line was found, configure the GPIO line to output and set value
+ * according to given options.
*
* Return: %0 on success or no-op, or a negative error number on failure.
*/
@@ -282,12 +342,24 @@ int i2c_of_probe_simple_enable(struct device *dev, struct device_node *bus_node,
if (ret)
goto out_put_node;
- ret = i2c_of_probe_simple_enable_regulator(dev, ctx);
+ ret = i2c_of_probe_simple_get_gpiod(dev, node, ctx);
if (ret)
goto out_put_supply;
+ ret = i2c_of_probe_simple_enable_regulator(dev, ctx);
+ if (ret)
+ goto out_put_gpiod;
+
+ ret = i2c_of_probe_simple_set_gpio(dev, ctx);
+ if (ret)
+ goto out_disable_regulator;
+
return 0;
+out_disable_regulator:
+ i2c_of_probe_simple_disable_regulator(dev, ctx);
+out_put_gpiod:
+ i2c_of_probe_simple_put_gpiod(ctx);
out_put_supply:
i2c_of_probe_simple_put_supply(ctx);
out_put_node:
@@ -296,17 +368,40 @@ int i2c_of_probe_simple_enable(struct device *dev, struct device_node *bus_node,
}
EXPORT_SYMBOL_NS_GPL(i2c_of_probe_simple_enable, I2C_OF_PROBER);
+/**
+ * i2c_of_probe_simple_cleanup_early - \
+ * Simple helper for I2C OF prober to release GPIOs before component is enabled
+ * @dev: Pointer to the &struct device of the caller; unused.
+ * @data: Pointer to &struct i2c_of_probe_simple_ctx helper context.
+ *
+ * GPIO descriptors are exclusive and have to be released before the
+ * actual driver probes so that the latter can acquire them.
+ */
+void i2c_of_probe_simple_cleanup_early(struct device *dev, void *data)
+{
+ struct i2c_of_probe_simple_ctx *ctx = data;
+
+ i2c_of_probe_simple_put_gpiod(ctx);
+}
+EXPORT_SYMBOL_NS_GPL(i2c_of_probe_simple_cleanup_early, I2C_OF_PROBER);
+
/**
* i2c_of_probe_simple_cleanup - Clean up and release resources for I2C OF prober simple helpers
* @dev: Pointer to the &struct device of the caller, only used for dev_printk() messages
* @data: Pointer to &struct i2c_of_probe_simple_ctx helper context.
*
+ * * If a GPIO line was found and not yet released, set its value to the opposite of that
+ * set in i2c_of_probe_simple_enable() and release it.
* * If a regulator supply was found, disable that regulator and release it.
*/
void i2c_of_probe_simple_cleanup(struct device *dev, void *data)
{
struct i2c_of_probe_simple_ctx *ctx = data;
+ /* GPIO operations here are no-ops if i2c_of_probe_simple_cleanup_early was called. */
+ i2c_of_probe_simple_disable_gpio(dev, ctx);
+ i2c_of_probe_simple_put_gpiod(ctx);
+
i2c_of_probe_simple_disable_regulator(dev, ctx);
i2c_of_probe_simple_put_supply(ctx);
}
@@ -314,6 +409,7 @@ EXPORT_SYMBOL_NS_GPL(i2c_of_probe_simple_cleanup, I2C_OF_PROBER);
struct i2c_of_probe_ops i2c_of_probe_simple_ops = {
.enable = i2c_of_probe_simple_enable,
+ .cleanup_early = i2c_of_probe_simple_cleanup_early,
.cleanup = i2c_of_probe_simple_cleanup,
};
EXPORT_SYMBOL_NS_GPL(i2c_of_probe_simple_ops, I2C_OF_PROBER);
@@ -9,6 +9,7 @@
#define _LINUX_I2C_OF_PROBER_H
#include <linux/kconfig.h>
+#include <linux/types.h>
struct device;
struct device_node;
@@ -85,6 +86,7 @@ int i2c_of_probe_component(struct device *dev, const struct i2c_of_probe_cfg *cf
*
* The following helpers are provided:
* * i2c_of_probe_simple_enable()
+ * * i2c_of_probe_simple_cleanup_early()
* * i2c_of_probe_simple_cleanup()
*/
@@ -92,14 +94,31 @@ int i2c_of_probe_component(struct device *dev, const struct i2c_of_probe_cfg *cf
* struct i2c_of_probe_simple_opts - Options for simple I2C component prober callbacks
* @res_node_compatible: Compatible string of device node to retrieve resources from.
* @supply_name: Name of regulator supply.
+ * @gpio_name: Name of GPIO. NULL if no GPIO line is used. Empty string ("") if GPIO
+ * line is unnamed.
* @post_power_on_delay_ms: Delay after regulators are powered on. Passed to msleep().
+ * @post_gpio_config_delay_ms: Delay after GPIO is configured. Passed to msleep().
+ * @gpio_assert_to_enable: %true if GPIO should be asserted, i.e. set to logical high,
+ * to enable the component.
+ *
+ * This describes power sequences common for the class of components supported by the
+ * simple component prober:
+ * * @gpio_name is configured to the non-active setting according to @gpio_assert_to_enable.
+ * * @supply_name regulator supply is enabled.
+ * * Wait for @post_power_on_delay_ms to pass.
+ * * @gpio_name is configured to the active setting according to @gpio_assert_to_enable.
+ * * Wait for @post_gpio_config_delay_ms to pass.
*/
struct i2c_of_probe_simple_opts {
const char *res_node_compatible;
const char *supply_name;
+ const char *gpio_name;
unsigned int post_power_on_delay_ms;
+ unsigned int post_gpio_config_delay_ms;
+ bool gpio_assert_to_enable;
};
+struct gpio_desc;
struct regulator;
struct i2c_of_probe_simple_ctx {
@@ -107,9 +126,11 @@ struct i2c_of_probe_simple_ctx {
const struct i2c_of_probe_simple_opts *opts;
/* private: internal fields for helpers. */
struct regulator *supply;
+ struct gpio_desc *gpiod;
};
int i2c_of_probe_simple_enable(struct device *dev, struct device_node *bus_node, void *data);
+void i2c_of_probe_simple_cleanup_early(struct device *dev, void *data);
void i2c_of_probe_simple_cleanup(struct device *dev, void *data);
extern struct i2c_of_probe_ops i2c_of_probe_simple_ops;