Commit 01ef6601 authored by Dmitry Torokhov's avatar Dmitry Torokhov
Browse files

Input: rotary-encoder - remove references to platform data from docs



The driver has been converted to use generic device properties, so
stop referring to platform data.
Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
parent b8a91560
......@@ -81,48 +81,51 @@ Board integration
To use this driver in your system, register a platform_device with the
name 'rotary-encoder' and associate the IRQs and some specific platform
data with it.
data with it. Because the driver uses generic device properties, this can
be done either via device tree, ACPI, or using static board files, like in
example below:
struct rotary_encoder_platform_data is declared in
include/linux/rotary-encoder.h and needs to be filled with the number of
steps the encoder has and can carry information about externally inverted
signals (because of an inverting buffer or other reasons). The encoder
can be set up to deliver input information as either an absolute or relative
axes. For relative axes the input event returns +/-1 for each step. For
absolute axes the position of the encoder can either roll over between zero
and the number of steps or will clamp at the maximum and zero depending on
the configuration.
::
Because GPIO to IRQ mapping is platform specific, this information must
be given in separately to the driver. See the example below.
/* board support file example */
::
#include <linux/input.h>
#include <linux/gpio/machine.h>
#include <linux/property.h>
#define GPIO_ROTARY_A 1
#define GPIO_ROTARY_B 2
static struct gpiod_lookup_table rotary_encoder_gpios = {
.dev_id = "rotary-encoder.0",
.table = {
GPIO_LOOKUP_IDX("gpio-0",
GPIO_ROTARY_A, NULL, 0, GPIO_ACTIVE_LOW),
GPIO_LOOKUP_IDX("gpio-0",
GPIO_ROTARY_B, NULL, 1, GPIO_ACTIVE_HIGH),
{ },
},
};
static const struct property_entry rotary_encoder_properties[] __initconst = {
PROPERTY_ENTRY_INTEGER("rotary-encoder,steps-per-period", u32, 24),
PROPERTY_ENTRY_INTEGER("linux,axis", u32, ABS_X),
PROPERTY_ENTRY_INTEGER("rotary-encoder,relative_axis", u32, 0),
{ },
};
static struct platform_device rotary_encoder_device = {
.name = "rotary-encoder",
.id = 0,
};
...
gpiod_add_lookup_table(&rotary_encoder_gpios);
device_add_properties(&rotary_encoder_device, rotary_encoder_properties);
platform_device_register(&rotary_encoder_device);
...
/* board support file example */
#include <linux/input.h>
#include <linux/rotary_encoder.h>
#define GPIO_ROTARY_A 1
#define GPIO_ROTARY_B 2
static struct rotary_encoder_platform_data my_rotary_encoder_info = {
.steps = 24,
.axis = ABS_X,
.relative_axis = false,
.rollover = false,
.gpio_a = GPIO_ROTARY_A,
.gpio_b = GPIO_ROTARY_B,
.inverted_a = 0,
.inverted_b = 0,
.half_period = false,
.wakeup_source = false,
};
static struct platform_device rotary_encoder_device = {
.name = "rotary-encoder",
.id = 0,
.dev = {
.platform_data = &my_rotary_encoder_info,
}
};
Please consult device tree binding documentation to see all properties
supported by the driver.
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