diff --git a/Documentation/w1/masters/w1-gpio b/Documentation/w1/masters/w1-gpio index af5d3b4aa851..623961d9e83f 100644 --- a/Documentation/w1/masters/w1-gpio +++ b/Documentation/w1/masters/w1-gpio @@ -8,17 +8,27 @@ Description ----------- GPIO 1-wire bus master driver. The driver uses the GPIO API to control the -wire and the GPIO pin can be specified using platform data. +wire and the GPIO pin can be specified using GPIO machine descriptor tables. +It is also possible to define the master using device tree, see +Documentation/devicetree/bindings/w1/w1-gpio.txt Example (mach-at91) ------------------- +#include #include +static struct gpiod_lookup_table foo_w1_gpiod_table = { + .dev_id = "w1-gpio", + .table = { + GPIO_LOOKUP_IDX("at91-gpio", AT91_PIN_PB20, NULL, 0, + GPIO_ACTIVE_HIGH|GPIO_OPEN_DRAIN), + }, +}; + static struct w1_gpio_platform_data foo_w1_gpio_pdata = { - .pin = AT91_PIN_PB20, - .is_open_drain = 1, + .ext_pullup_enable_pin = -EINVAL, }; static struct platform_device foo_w1_device = { @@ -30,4 +40,5 @@ static struct platform_device foo_w1_device = { ... at91_set_GPIO_periph(foo_w1_gpio_pdata.pin, 1); at91_set_multi_drive(foo_w1_gpio_pdata.pin, 1); + gpiod_add_lookup_table(&foo_w1_gpiod_table); platform_device_register(&foo_w1_device); diff --git a/arch/arm/mach-ixp4xx/vulcan-setup.c b/arch/arm/mach-ixp4xx/vulcan-setup.c index 731fb2019ecb..2c03d2f6b647 100644 --- a/arch/arm/mach-ixp4xx/vulcan-setup.c +++ b/arch/arm/mach-ixp4xx/vulcan-setup.c @@ -16,6 +16,7 @@ #include #include #include +#include #include #include #include @@ -162,9 +163,16 @@ static struct platform_device vulcan_max6369 = { .num_resources = 1, }; +static struct gpiod_lookup_table vulcan_w1_gpiod_table = { + .dev_id = "w1-gpio", + .table = { + GPIO_LOOKUP_IDX("IXP4XX_GPIO_CHIP", 14, NULL, 0, + GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN), + }, +}; + static struct w1_gpio_platform_data vulcan_w1_gpio_pdata = { - .pin = 14, - .ext_pullup_enable_pin = -EINVAL, + /* Intentionally left blank */ }; static struct platform_device vulcan_w1_gpio = { @@ -233,6 +241,7 @@ static void __init vulcan_init(void) IXP4XX_EXP_BUS_WR_EN | IXP4XX_EXP_BUS_BYTE_EN; + gpiod_add_lookup_table(&vulcan_w1_gpiod_table); platform_add_devices(vulcan_devices, ARRAY_SIZE(vulcan_devices)); } diff --git a/arch/arm/mach-pxa/raumfeld.c b/arch/arm/mach-pxa/raumfeld.c index 9d662fed03ec..feddca7f3540 100644 --- a/arch/arm/mach-pxa/raumfeld.c +++ b/arch/arm/mach-pxa/raumfeld.c @@ -506,11 +506,16 @@ static void w1_enable_external_pullup(int enable) msleep(100); } +static struct gpiod_lookup_table raumfeld_w1_gpiod_table = { + .dev_id = "w1-gpio", + .table = { + GPIO_LOOKUP_IDX("gpio-pxa", GPIO_ONE_WIRE, NULL, 0, + GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN), + }, +}; + static struct w1_gpio_platform_data w1_gpio_platform_data = { - .pin = GPIO_ONE_WIRE, - .is_open_drain = 0, - .enable_external_pullup = w1_enable_external_pullup, - .ext_pullup_enable_pin = -EINVAL, + .enable_external_pullup = w1_enable_external_pullup, }; static struct platform_device raumfeld_w1_gpio_device = { @@ -523,13 +528,14 @@ static struct platform_device raumfeld_w1_gpio_device = { static void __init raumfeld_w1_init(void) { int ret = gpio_request(GPIO_W1_PULLUP_ENABLE, - "W1 external pullup enable"); + "W1 external pullup enable"); if (ret < 0) pr_warn("Unable to request GPIO_W1_PULLUP_ENABLE\n"); else gpio_direction_output(GPIO_W1_PULLUP_ENABLE, 0); + gpiod_add_lookup_table(&raumfeld_w1_gpiod_table); platform_device_register(&raumfeld_w1_gpio_device); } diff --git a/drivers/w1/masters/w1-gpio.c b/drivers/w1/masters/w1-gpio.c index a90728ceec5a..55e11bf8ebaf 100644 --- a/drivers/w1/masters/w1-gpio.c +++ b/drivers/w1/masters/w1-gpio.c @@ -13,9 +13,8 @@ #include #include #include -#include +#include #include -#include #include #include #include @@ -30,11 +29,17 @@ static u8 w1_gpio_set_pullup(void *data, int delay) pdata->pullup_duration = delay; } else { if (pdata->pullup_duration) { - gpio_direction_output(pdata->pin, 1); - + /* + * This will OVERRIDE open drain emulation and force-pull + * the line high for some time. + */ + gpiod_set_raw_value(pdata->gpiod, 1); msleep(pdata->pullup_duration); - - gpio_direction_input(pdata->pin); + /* + * This will simply set the line as input since we are doing + * open drain emulation in the GPIO library. + */ + gpiod_set_value(pdata->gpiod, 1); } pdata->pullup_duration = 0; } @@ -42,28 +47,18 @@ static u8 w1_gpio_set_pullup(void *data, int delay) return 0; } -static void w1_gpio_write_bit_dir(void *data, u8 bit) +static void w1_gpio_write_bit(void *data, u8 bit) { struct w1_gpio_platform_data *pdata = data; - if (bit) - gpio_direction_input(pdata->pin); - else - gpio_direction_output(pdata->pin, 0); -} - -static void w1_gpio_write_bit_val(void *data, u8 bit) -{ - struct w1_gpio_platform_data *pdata = data; - - gpio_set_value(pdata->pin, bit); + gpiod_set_value(pdata->gpiod, bit); } static u8 w1_gpio_read_bit(void *data) { struct w1_gpio_platform_data *pdata = data; - return gpio_get_value(pdata->pin) ? 1 : 0; + return gpiod_get_value(pdata->gpiod) ? 1 : 0; } #if defined(CONFIG_OF) @@ -74,107 +69,85 @@ static const struct of_device_id w1_gpio_dt_ids[] = { MODULE_DEVICE_TABLE(of, w1_gpio_dt_ids); #endif -static int w1_gpio_probe_dt(struct platform_device *pdev) -{ - struct w1_gpio_platform_data *pdata = dev_get_platdata(&pdev->dev); - struct device_node *np = pdev->dev.of_node; - int gpio; - - pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); - if (!pdata) - return -ENOMEM; - - if (of_get_property(np, "linux,open-drain", NULL)) - pdata->is_open_drain = 1; - - gpio = of_get_gpio(np, 0); - if (gpio < 0) { - if (gpio != -EPROBE_DEFER) - dev_err(&pdev->dev, - "Failed to parse gpio property for data pin (%d)\n", - gpio); - - return gpio; - } - pdata->pin = gpio; - - gpio = of_get_gpio(np, 1); - if (gpio == -EPROBE_DEFER) - return gpio; - /* ignore other errors as the pullup gpio is optional */ - pdata->ext_pullup_enable_pin = gpio; - - pdev->dev.platform_data = pdata; - - return 0; -} - static int w1_gpio_probe(struct platform_device *pdev) { struct w1_bus_master *master; struct w1_gpio_platform_data *pdata; + struct device *dev = &pdev->dev; + struct device_node *np = dev->of_node; + /* Enforce open drain mode by default */ + enum gpiod_flags gflags = GPIOD_OUT_LOW_OPEN_DRAIN; int err; if (of_have_populated_dt()) { - err = w1_gpio_probe_dt(pdev); - if (err < 0) - return err; - } + pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); + if (!pdata) + return -ENOMEM; - pdata = dev_get_platdata(&pdev->dev); + /* + * This parameter means that something else than the gpiolib has + * already set the line into open drain mode, so we should just + * driver it high/low like we are in full control of the line and + * open drain will happen transparently. + */ + if (of_get_property(np, "linux,open-drain", NULL)) + gflags = GPIOD_OUT_LOW; + + pdev->dev.platform_data = pdata; + } + pdata = dev_get_platdata(dev); if (!pdata) { - dev_err(&pdev->dev, "No configuration data\n"); + dev_err(dev, "No configuration data\n"); return -ENXIO; } - master = devm_kzalloc(&pdev->dev, sizeof(struct w1_bus_master), + master = devm_kzalloc(dev, sizeof(struct w1_bus_master), GFP_KERNEL); if (!master) { - dev_err(&pdev->dev, "Out of memory\n"); + dev_err(dev, "Out of memory\n"); return -ENOMEM; } - err = devm_gpio_request(&pdev->dev, pdata->pin, "w1"); - if (err) { - dev_err(&pdev->dev, "gpio_request (pin) failed\n"); - return err; + pdata->gpiod = devm_gpiod_get_index(dev, NULL, 0, gflags); + if (IS_ERR(pdata->gpiod)) { + dev_err(dev, "gpio_request (pin) failed\n"); + return PTR_ERR(pdata->gpiod); } - if (gpio_is_valid(pdata->ext_pullup_enable_pin)) { - err = devm_gpio_request_one(&pdev->dev, - pdata->ext_pullup_enable_pin, GPIOF_INIT_LOW, - "w1 pullup"); - if (err < 0) { - dev_err(&pdev->dev, "gpio_request_one " - "(ext_pullup_enable_pin) failed\n"); - return err; - } + pdata->pullup_gpiod = + devm_gpiod_get_index_optional(dev, NULL, 1, GPIOD_OUT_LOW); + if (IS_ERR(pdata->pullup_gpiod)) { + dev_err(dev, "gpio_request_one " + "(ext_pullup_enable_pin) failed\n"); + return PTR_ERR(pdata->pullup_gpiod); } master->data = pdata; master->read_bit = w1_gpio_read_bit; + gpiod_direction_output(pdata->gpiod, 1); + master->write_bit = w1_gpio_write_bit; - if (pdata->is_open_drain) { - gpio_direction_output(pdata->pin, 1); - master->write_bit = w1_gpio_write_bit_val; - } else { - gpio_direction_input(pdata->pin); - master->write_bit = w1_gpio_write_bit_dir; + /* + * If we are using open drain emulation from the GPIO library, + * we need to use this pullup function that hammers the line + * high using a raw accessor to provide pull-up for the w1 + * line. + */ + if (gflags == GPIOD_OUT_LOW_OPEN_DRAIN) master->set_pullup = w1_gpio_set_pullup; - } err = w1_add_master_device(master); if (err) { - dev_err(&pdev->dev, "w1_add_master device failed\n"); + dev_err(dev, "w1_add_master device failed\n"); return err; } if (pdata->enable_external_pullup) pdata->enable_external_pullup(1); - if (gpio_is_valid(pdata->ext_pullup_enable_pin)) - gpio_set_value(pdata->ext_pullup_enable_pin, 1); + if (pdata->pullup_gpiod) + gpiod_set_value(pdata->pullup_gpiod, 1); platform_set_drvdata(pdev, master); @@ -189,8 +162,8 @@ static int w1_gpio_remove(struct platform_device *pdev) if (pdata->enable_external_pullup) pdata->enable_external_pullup(0); - if (gpio_is_valid(pdata->ext_pullup_enable_pin)) - gpio_set_value(pdata->ext_pullup_enable_pin, 0); + if (pdata->pullup_gpiod) + gpiod_set_value(pdata->pullup_gpiod, 0); w1_remove_master_device(master); diff --git a/include/linux/w1-gpio.h b/include/linux/w1-gpio.h index d58594a32324..78901ecd2f95 100644 --- a/include/linux/w1-gpio.h +++ b/include/linux/w1-gpio.h @@ -10,16 +10,15 @@ #ifndef _LINUX_W1_GPIO_H #define _LINUX_W1_GPIO_H +struct gpio_desc; + /** * struct w1_gpio_platform_data - Platform-dependent data for w1-gpio - * @pin: GPIO pin to use - * @is_open_drain: GPIO pin is configured as open drain */ struct w1_gpio_platform_data { - unsigned int pin; - unsigned int is_open_drain:1; + struct gpio_desc *gpiod; + struct gpio_desc *pullup_gpiod; void (*enable_external_pullup)(int enable); - unsigned int ext_pullup_enable_pin; unsigned int pullup_duration; };