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-rw-r--r--Documentation/w1/masters/w1-gpio17
-rw-r--r--arch/arm/mach-ixp4xx/vulcan-setup.c13
-rw-r--r--arch/arm/mach-pxa/raumfeld.c16
-rw-r--r--drivers/w1/masters/w1-gpio.c149
-rw-r--r--include/linux/w1-gpio.h9
5 files changed, 101 insertions, 103 deletions
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 <linux/gpio/machine.h>
#include <linux/w1-gpio.h>
+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 <linux/serial_8250.h>
#include <linux/io.h>
#include <linux/w1-gpio.h>
+#include <linux/gpio/machine.h>
#include <linux/mtd/plat-ram.h>
#include <asm/mach-types.h>
#include <asm/mach/arch.h>
@@ -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 <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/w1-gpio.h>
-#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
#include <linux/of_platform.h>
-#include <linux/of_gpio.h>
#include <linux/err.h>
#include <linux/of.h>
#include <linux/delay.h>
@@ -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)
-{
- 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)
+static void w1_gpio_write_bit(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;
+
+ /*
+ * 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(&pdev->dev);
+ 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;
-
- 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;
+ gpiod_direction_output(pdata->gpiod, 1);
+ master->write_bit = w1_gpio_write_bit;
+
+ /*
+ * 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;
};
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-01 02:16:07 +0000