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input: gpio_keys: implement polling mode support
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Some MCU have limitations with GPIO interrupts. Add a polling mode to
the gpio-keys driver to support those cases.

This required a bit of a refactoring of the driver data structure to add
a instance wide data, and move the pin specific pointer in the config
structure.

For polling, reuse the button 0 delayed work so we minimize the resource
waste, the two work handler functions are only referenced when used so
at least those are discarded automatically if no instance needs them.

Fix a bug in the PM structure instantiation as well.

Signed-off-by: Fabio Baltieri <fabiobaltieri@google.com>
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fabiobaltieri committed Jan 4, 2024
1 parent 89982b7 commit 558c30c
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Showing 3 changed files with 106 additions and 18 deletions.
106 changes: 88 additions & 18 deletions drivers/input/input_gpio_keys.c
View file
Expand Up @@ -13,6 +13,7 @@
#include <zephyr/logging/log.h>
#include <zephyr/pm/device.h>
#include <zephyr/pm/device_runtime.h>
#include <zephyr/sys/atomic.h>

LOG_MODULE_REGISTER(gpio_keys, CONFIG_INPUT_LOG_LEVEL);

Expand All @@ -27,33 +28,41 @@ struct gpio_keys_pin_config {
/** Zephyr code from devicetree */
uint32_t zephyr_code;
};

struct gpio_keys_pin_data {
const struct device *dev;
struct gpio_keys_callback cb_data;
struct k_work_delayable work;
int8_t pin_state;
};

struct gpio_keys_config {
/** Debounce interval in milliseconds from devicetree */
uint32_t debounce_interval_ms;
const int num_keys;
const struct gpio_keys_pin_config *pin_cfg;
struct gpio_keys_pin_data *pin_data;
k_work_handler_t handler;
bool no_interrupts;
};

struct gpio_keys_pin_data {
const struct device *dev;
struct gpio_keys_callback cb_data;
struct k_work_delayable work;
int8_t pin_state;
struct gpio_keys_data {
#ifdef CONFIG_PM_DEVICE
atomic_t suspended;
#endif
};

/**
* Handle debounced gpio pin state.
*/
static void gpio_keys_change_deferred(struct k_work *work)
static void gpio_keys_poll_pin(const struct device *dev, int key_index)
{
struct k_work_delayable *dwork = k_work_delayable_from_work(work);
struct gpio_keys_pin_data *pin_data = CONTAINER_OF(dwork, struct gpio_keys_pin_data, work);
const struct device *dev = pin_data->dev;
int key_index = pin_data - (struct gpio_keys_pin_data *)dev->data;
const struct gpio_keys_config *cfg = dev->config;
const struct gpio_keys_pin_config *pin_cfg = &cfg->pin_cfg[key_index];
struct gpio_keys_pin_data *pin_data = &cfg->pin_data[key_index];
int new_pressed;

const int new_pressed = gpio_pin_get(pin_cfg->spec.port, pin_cfg->spec.pin);
new_pressed = gpio_pin_get(pin_cfg->spec.port, pin_cfg->spec.pin);

LOG_DBG("gpio_change_deferred %s pin_state=%d, new_pressed=%d, key_index=%d", dev->name,
pin_data->cb_data.pin_state, new_pressed, key_index);
Expand All @@ -67,6 +76,39 @@ static void gpio_keys_change_deferred(struct k_work *work)
}
}

static __maybe_unused void gpio_keys_poll_pins(struct k_work *work)
{
struct k_work_delayable *dwork = k_work_delayable_from_work(work);
struct gpio_keys_pin_data *pin_data = CONTAINER_OF(dwork, struct gpio_keys_pin_data, work);
const struct device *dev = pin_data->dev;
const struct gpio_keys_config *cfg = dev->config;

#ifdef CONFIG_PM_DEVICE
struct gpio_keys_data *data = dev->data;

if (atomic_get(&data->suspended) == 1) {
return;
}
#endif

for (int i = 0; i < cfg->num_keys; i++) {
gpio_keys_poll_pin(dev, i);
}

k_work_reschedule(dwork, K_MSEC(cfg->debounce_interval_ms));
}

static __maybe_unused void gpio_keys_change_deferred(struct k_work *work)
{
struct k_work_delayable *dwork = k_work_delayable_from_work(work);
struct gpio_keys_pin_data *pin_data = CONTAINER_OF(dwork, struct gpio_keys_pin_data, work);
const struct device *dev = pin_data->dev;
const struct gpio_keys_config *cfg = dev->config;
int key_index = pin_data - (struct gpio_keys_pin_data *)cfg->pin_data;

gpio_keys_poll_pin(dev, key_index);
}

static void gpio_keys_interrupt(const struct device *dev, struct gpio_callback *cbdata,
uint32_t pins)
{
Expand Down Expand Up @@ -110,8 +152,8 @@ static int gpio_keys_interrupt_configure(const struct gpio_dt_spec *gpio_spec,

static int gpio_keys_init(const struct device *dev)
{
struct gpio_keys_pin_data *pin_data = dev->data;
const struct gpio_keys_config *cfg = dev->config;
struct gpio_keys_pin_data *pin_data = cfg->pin_data;
int ret;

for (int i = 0; i < cfg->num_keys; i++) {
Expand All @@ -129,7 +171,11 @@ static int gpio_keys_init(const struct device *dev)
}

pin_data[i].dev = dev;
k_work_init_delayable(&pin_data[i].work, gpio_keys_change_deferred);
k_work_init_delayable(&pin_data[i].work, cfg->handler);

if (cfg->no_interrupts) {
continue;
}

ret = gpio_keys_interrupt_configure(&cfg->pin_cfg[i].spec,
&pin_data[i].cb_data,
Expand All @@ -140,6 +186,11 @@ static int gpio_keys_init(const struct device *dev)
}
}

if (cfg->no_interrupts) {
/* use pin 0 work to poll all the pins periodically */
k_work_reschedule(&pin_data[0].work, K_MSEC(cfg->debounce_interval_ms));
}

ret = pm_device_runtime_enable(dev);
if (ret < 0) {
LOG_ERR("Failed to enable runtime power management");
Expand All @@ -154,6 +205,8 @@ static int gpio_keys_pm_action(const struct device *dev,
enum pm_device_action action)
{
const struct gpio_keys_config *cfg = dev->config;
struct gpio_keys_data *data = dev->data;
struct gpio_keys_pin_data *pin_data = cfg->pin_data;
gpio_flags_t gpio_flags;
gpio_flags_t int_flags;
int ret;
Expand All @@ -162,10 +215,12 @@ static int gpio_keys_pm_action(const struct device *dev,
case PM_DEVICE_ACTION_SUSPEND:
gpio_flags = GPIO_DISCONNECTED;
int_flags = GPIO_INT_DISABLE;
atomic_set(&data->suspended, 1);
break;
case PM_DEVICE_ACTION_RESUME:
gpio_flags = GPIO_INPUT;
int_flags = GPIO_INT_EDGE_BOTH;
atomic_set(&data->suspended, 0);
break;
default:
return -ENOTSUP;
Expand All @@ -180,13 +235,22 @@ static int gpio_keys_pm_action(const struct device *dev,
return ret;
}

if (cfg->no_interrupts) {
continue;
}

ret = gpio_pin_interrupt_configure_dt(gpio, int_flags);
if (ret < 0) {
LOG_ERR("interrupt configuration failed: %d", ret);
return ret;
}
}

if (action == PM_DEVICE_ACTION_RESUME && cfg->no_interrupts) {
k_work_reschedule(&pin_data[0].work,
K_MSEC(cfg->debounce_interval_ms));
}

return 0;
}
#endif
Expand All @@ -207,19 +271,25 @@ static int gpio_keys_pm_action(const struct device *dev,
static const struct gpio_keys_pin_config gpio_keys_pin_config_##i[] = { \
DT_INST_FOREACH_CHILD_STATUS_OKAY_SEP(i, GPIO_KEYS_CFG_DEF, (,))}; \
\
static struct gpio_keys_pin_data \
gpio_keys_pin_data_##i[ARRAY_SIZE(gpio_keys_pin_config_##i)]; \
\
static const struct gpio_keys_config gpio_keys_config_##i = { \
.debounce_interval_ms = DT_INST_PROP(i, debounce_interval_ms), \
.num_keys = ARRAY_SIZE(gpio_keys_pin_config_##i), \
.pin_cfg = gpio_keys_pin_config_##i, \
.pin_data = gpio_keys_pin_data_##i, \
.handler = COND_CODE_1(DT_INST_PROP(i, no_interrupts), \
(gpio_keys_poll_pins), (gpio_keys_change_deferred)), \
.no_interrupts = DT_INST_PROP(i, no_interrupts), \
}; \
\
static struct gpio_keys_pin_data \
gpio_keys_pin_data_##i[ARRAY_SIZE(gpio_keys_pin_config_##i)]; \
static struct gpio_keys_data gpio_keys_data_##i; \
\
PM_DEVICE_DT_INST_DEFINE(n, gpio_keys_pm_action); \
PM_DEVICE_DT_INST_DEFINE(i, gpio_keys_pm_action); \
\
DEVICE_DT_INST_DEFINE(i, &gpio_keys_init, PM_DEVICE_DT_INST_GET(n), \
gpio_keys_pin_data_##i, &gpio_keys_config_##i, \
DEVICE_DT_INST_DEFINE(i, &gpio_keys_init, PM_DEVICE_DT_INST_GET(i), \
&gpio_keys_data_##i, &gpio_keys_config_##i, \
POST_KERNEL, CONFIG_INPUT_INIT_PRIORITY, NULL);

DT_INST_FOREACH_STATUS_OKAY(GPIO_KEYS_INIT)
8 changes: 8 additions & 0 deletions dts/bindings/input/gpio-keys.yaml
View file
Expand Up @@ -35,15 +35,23 @@ properties:
Debouncing interval time in milliseconds.
If not specified defaults to 30.
no-interrupts:
type: boolean
description: |
Do not use interrupts for the key GPIOs, poll the pin periodically at the
specified debounce-interval-ms instead.
child-binding:
description: GPIO KEYS child node
properties:
gpios:
type: phandle-array
required: true

label:
type: string
description: Descriptive name of the key

zephyr,code:
type: int
description: Key code to emit.
10 changes: 10 additions & 0 deletions tests/drivers/build_all/input/app.overlay
View file
Expand Up @@ -26,6 +26,16 @@
};
};

gpio-keys-polled {
compatible = "gpio-keys";
debounce-interval-ms = <30>;
button_0 {
gpios = <&test_gpio 0 0>;
zephyr,code = <0>;
};
no-interrupts;
};

evdev {
compatible = "zephyr,native-linux-evdev";
};
Expand Down

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