Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 44 insertions, 0 deletions

diff --git a/Documentation/w1/masters/w1-gpio b/Documentation/w1/masters/w1-gpio
new file mode 100644
index 000000000..623961d9e
--- /dev/null
+++ b/Documentation/w1/masters/w1-gpio
@@ -0,0 +1,44 @@
+Kernel driver w1-gpio
+=====================
+
+Author: Ville Syrjala <syrjala@sci.fi>
+
+
+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 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 = {
+	.ext_pullup_enable_pin	= -EINVAL,
+};
+
+static struct platform_device foo_w1_device = {
+	.name			= "w1-gpio",
+	.id			= -1,
+	.dev.platform_data	= &foo_w1_gpio_pdata,
+};
+
+...
+	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);