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#include <linux/delay.h>
struct gpio_pin *gpio_pin_by_name(const char *name) {
struct gpio_pin *pin;
for (pin = gpio_pins; *pin->name; pin++) {
if (!strcmp(pin->name, name)) {
return pin;
}
}
log_error("pin named %s not found", name);
return NULL;
}
// A GPIO pin number must only occur once.
struct gpio_pin *gpio_pin_by_num(unsigned num) {
int ipin = 0;
while(*(gpio_pins[ipin].name)) {
if (gpio_pins[ipin].pin.gpio == num) {
return &(gpio_pins[ipin]);
}
ipin++;
}
log_error("pin numbered %u not found", num);
return NULL;
}
struct gpio_pin *gpio_pin_by_attr_name(const char *name) {
struct gpio_pin *pin;
for (pin = gpio_pins; *pin->name; pin++) {
if (!strcmp(pin->pin.label, name)) {
return pin;
}
}
log_error("pin with attr name %s not found", name);
return NULL;
}
/* Any gpio that could potentially get routed over an i2c bus
* as opposed to a memory write to a register must call
* "cansleep" versions of gpio functions. The purpose of the
* function is to remind kernel driver writers that any GPIO
* routed over i2c (or spi) cannot be accessed in an interrupt
* handler. Interrupt handlers should use the GPIO pins
* that are memory mapped. gpio_get_value and gpio_set_value
* cannot be used with the PCA 9557 or a dump will result. */
ssize_t mts_attr_show_gpio_pin(struct device *dev,
struct device_attribute *attr,
char *buf)
{
int value;
struct gpio_pin *pin = gpio_pin_by_attr_name(attr->attr.name);
if (!pin) {
return -ENODEV;
}
mutex_lock(&mts_io_mutex);
value = gpio_get_value_cansleep(pin->pin.gpio);
mutex_unlock(&mts_io_mutex);
if (value < 0) {
return value;
}
if (pin->active_low) {
value = !value;
}
return sprintf(buf, "%d\n", value);
}
static ssize_t mts_attr_store_gpio_pin(struct device *dev,
struct device_attribute *attr, const char *buf, size_t count)
{
int value;
struct gpio_pin *pin = gpio_pin_by_attr_name(attr->attr.name);
if (!pin) {
return -ENODEV;
}
if (sscanf(buf, "%i", &value) != 1) {
return -EINVAL;
}
if (pin->active_low) {
value = !value;
}
mutex_lock(&mts_io_mutex);
gpio_set_value_cansleep(pin->pin.gpio, value);
mutex_unlock(&mts_io_mutex);
return count;
}
static int reset_gpio_pin(struct gpio_pin *pin, unsigned int delay_ms, unsigned int value)
{
if (!pin) {
return -ENODEV;
}
gpio_set_value_cansleep(pin->pin.gpio, value);
mdelay(delay_ms);
gpio_set_value_cansleep(pin->pin.gpio, !value);
return 0;
}
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