diff options
| -rw-r--r-- | drivers/i2c/muxes/i2c-mux-gpio.c | 38 | ||||
| -rw-r--r-- | include/linux/i2c-mux-gpio.h | 3 |
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; |