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-rw-r--r--drivers/i2c/muxes/i2c-mux-gpio.c38
-rw-r--r--include/linux/i2c-mux-gpio.h3
2 files changed, 35 insertions, 6 deletions
diff --git a/drivers/i2c/muxes/i2c-mux-gpio.c b/drivers/i2c/muxes/i2c-mux-gpio.c
index 7c23bb51bd33..566a6757a33d 100644
--- a/drivers/i2c/muxes/i2c-mux-gpio.c
+++ b/drivers/i2c/muxes/i2c-mux-gpio.c
@@ -21,6 +21,7 @@ struct gpiomux {
struct i2c_adapter *parent;
struct i2c_adapter **adap; /* child busses */
struct i2c_mux_gpio_platform_data data;
+ unsigned gpio_base;
};
static void i2c_mux_gpio_set(const struct gpiomux *mux, unsigned val)
@@ -28,7 +29,8 @@ static void i2c_mux_gpio_set(const struct gpiomux *mux, unsigned val)
int i;
for (i = 0; i < mux->data.n_gpios; i++)
- gpio_set_value(mux->data.gpios[i], val & (1 << i));
+ gpio_set_value(mux->gpio_base + mux->data.gpios[i],
+ val & (1 << i));
}
static int i2c_mux_gpio_select(struct i2c_adapter *adap, void *data, u32 chan)
@@ -49,13 +51,19 @@ static int i2c_mux_gpio_deselect(struct i2c_adapter *adap, void *data, u32 chan)
return 0;
}
+static int __devinit match_gpio_chip_by_label(struct gpio_chip *chip,
+ void *data)
+{
+ return !strcmp(chip->label, data);
+}
+
static int __devinit i2c_mux_gpio_probe(struct platform_device *pdev)
{
struct gpiomux *mux;
struct i2c_mux_gpio_platform_data *pdata;
struct i2c_adapter *parent;
int (*deselect) (struct i2c_adapter *, void *, u32);
- unsigned initial_state;
+ unsigned initial_state, gpio_base;
int i, ret;
pdata = pdev->dev.platform_data;
@@ -64,6 +72,23 @@ static int __devinit i2c_mux_gpio_probe(struct platform_device *pdev)
return -ENODEV;
}
+ /*
+ * If a GPIO chip name is provided, the GPIO pin numbers provided are
+ * relative to its base GPIO number. Otherwise they are absolute.
+ */
+ if (pdata->gpio_chip) {
+ struct gpio_chip *gpio;
+
+ gpio = gpiochip_find(pdata->gpio_chip,
+ match_gpio_chip_by_label);
+ if (!gpio)
+ return -EPROBE_DEFER;
+
+ gpio_base = gpio->base;
+ } else {
+ gpio_base = 0;
+ }
+
parent = i2c_get_adapter(pdata->parent);
if (!parent) {
dev_err(&pdev->dev, "Parent adapter (%d) not found\n",
@@ -79,6 +104,7 @@ static int __devinit i2c_mux_gpio_probe(struct platform_device *pdev)
mux->parent = parent;
mux->data = *pdata;
+ mux->gpio_base = gpio_base;
mux->adap = devm_kzalloc(&pdev->dev,
sizeof(*mux->adap) * pdata->n_values,
GFP_KERNEL);
@@ -96,10 +122,10 @@ static int __devinit i2c_mux_gpio_probe(struct platform_device *pdev)
}
for (i = 0; i < pdata->n_gpios; i++) {
- ret = gpio_request(pdata->gpios[i], "i2c-mux-gpio");
+ ret = gpio_request(gpio_base + pdata->gpios[i], "i2c-mux-gpio");
if (ret)
goto err_request_gpio;
- gpio_direction_output(pdata->gpios[i],
+ gpio_direction_output(gpio_base + pdata->gpios[i],
initial_state & (1 << i));
}
@@ -130,7 +156,7 @@ add_adapter_failed:
i = pdata->n_gpios;
err_request_gpio:
for (; i > 0; i--)
- gpio_free(pdata->gpios[i - 1]);
+ gpio_free(gpio_base + pdata->gpios[i - 1]);
alloc_failed:
i2c_put_adapter(parent);
@@ -146,7 +172,7 @@ static int __devexit i2c_mux_gpio_remove(struct platform_device *pdev)
i2c_del_mux_adapter(mux->adap[i]);
for (i = 0; i < mux->data.n_gpios; i++)
- gpio_free(mux->data.gpios[i]);
+ gpio_free(mux->gpio_base + mux->data.gpios[i]);
platform_set_drvdata(pdev, NULL);
i2c_put_adapter(mux->parent);
diff --git a/include/linux/i2c-mux-gpio.h b/include/linux/i2c-mux-gpio.h
index 4ea1cc7392bd..4406108201fe 100644
--- a/include/linux/i2c-mux-gpio.h
+++ b/include/linux/i2c-mux-gpio.h
@@ -22,6 +22,8 @@
* position
* @n_values: Number of multiplexer positions (busses to instantiate)
* @classes: Optional I2C auto-detection classes
+ * @gpio_chip: Optional GPIO chip name; if set, GPIO pin numbers are given
+ * relative to the base GPIO number of that chip
* @gpios: Array of GPIO numbers used to control MUX
* @n_gpios: Number of GPIOs used to control MUX
* @idle: Bitmask to write to MUX when idle or GPIO_I2CMUX_NO_IDLE if not used
@@ -32,6 +34,7 @@ struct i2c_mux_gpio_platform_data {
const unsigned *values;
int n_values;
const unsigned *classes;
+ char *gpio_chip;
const unsigned *gpios;
int n_gpios;
unsigned idle;