power: supply: gpio-charger: add charge-current-limit feature
Add new charge-current-limit feature to gpio-charger.
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
diff --git a/drivers/power/supply/gpio-charger.c b/drivers/power/supply/gpio-charger.c
index d7aff28..68212b3 100644
--- a/drivers/power/supply/gpio-charger.c
+++ b/drivers/power/supply/gpio-charger.c
@@ -17,7 +17,13 @@
#include <linux/power/gpio-charger.h>
+struct gpio_mapping {
+ u32 limit_ua;
+ u32 gpiodata;
+} __packed;
+
struct gpio_charger {
+ struct device *dev;
unsigned int irq;
unsigned int charge_status_irq;
bool wakeup_enabled;
@@ -26,6 +32,11 @@ struct gpio_charger {
struct power_supply_desc charger_desc;
struct gpio_desc *gpiod;
struct gpio_desc *charge_status;
+
+ struct gpio_descs *current_limit_gpios;
+ struct gpio_mapping *current_limit_map;
+ u32 current_limit_map_size;
+ u32 charge_current_limit;
};
static irqreturn_t gpio_charger_irq(int irq, void *devid)
@@ -42,6 +53,35 @@ static inline struct gpio_charger *psy_to_gpio_charger(struct power_supply *psy)
return power_supply_get_drvdata(psy);
}
+static int set_charge_current_limit(struct gpio_charger *gpio_charger, int val)
+{
+ struct gpio_mapping mapping;
+ int ndescs = gpio_charger->current_limit_gpios->ndescs;
+ struct gpio_desc **gpios = gpio_charger->current_limit_gpios->desc;
+ int i;
+
+ if (!gpio_charger->current_limit_map_size)
+ return -EINVAL;
+
+ for (i = 0; i < gpio_charger->current_limit_map_size; i++) {
+ if (gpio_charger->current_limit_map[i].limit_ua <= val)
+ break;
+ }
+ mapping = gpio_charger->current_limit_map[i];
+
+ for (i = 0; i < ndescs; i++) {
+ bool val = (mapping.gpiodata >> i) & 1;
+ gpiod_set_value_cansleep(gpios[ndescs-i-1], val);
+ }
+
+ gpio_charger->charge_current_limit = mapping.limit_ua;
+
+ dev_dbg(gpio_charger->dev, "set charge current limit to %d (requested: %d)\n",
+ gpio_charger->charge_current_limit, val);
+
+ return 0;
+}
+
static int gpio_charger_get_property(struct power_supply *psy,
enum power_supply_property psp, union power_supply_propval *val)
{
@@ -57,6 +97,9 @@ static int gpio_charger_get_property(struct power_supply *psy,
else
val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
break;
+ case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:
+ val->intval = gpio_charger->charge_current_limit;
+ break;
default:
return -EINVAL;
}
@@ -64,6 +107,34 @@ static int gpio_charger_get_property(struct power_supply *psy,
return 0;
}
+static int gpio_charger_set_property(struct power_supply *psy,
+ enum power_supply_property psp, const union power_supply_propval *val)
+{
+ struct gpio_charger *gpio_charger = psy_to_gpio_charger(psy);
+
+ switch (psp) {
+ case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:
+ return set_charge_current_limit(gpio_charger, val->intval);
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int gpio_charger_property_is_writeable(struct power_supply *psy,
+ enum power_supply_property psp)
+{
+ switch (psp) {
+ case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:
+ return 1;
+ default:
+ break;
+ }
+
+ return 0;
+}
+
static enum power_supply_type gpio_charger_get_type(struct device *dev)
{
const char *chargetype;
@@ -111,6 +182,61 @@ static int gpio_charger_get_irq(struct device *dev, void *dev_id,
return irq;
}
+static int init_charge_current_limit(struct device *dev,
+ struct gpio_charger *gpio_charger)
+{
+ int i, len;
+ u32 cur_limit = U32_MAX;
+
+ gpio_charger->current_limit_gpios = devm_gpiod_get_array_optional(dev,
+ "charge-current-limit", GPIOD_OUT_LOW);
+ if (IS_ERR(gpio_charger->current_limit_gpios)) {
+ dev_err(dev, "error getting current-limit GPIOs\n");
+ return PTR_ERR(gpio_charger->current_limit_gpios);
+ }
+
+ if (!gpio_charger->current_limit_gpios)
+ return 0;
+
+ len = device_property_read_u32_array(dev, "charge-current-limit-mapping",
+ NULL, 0);
+ if (len < 0)
+ return len;
+
+ if (len == 0 || len % 2) {
+ dev_err(dev, "invalid charge-current-limit-mapping length\n");
+ return -EINVAL;
+ }
+
+ gpio_charger->current_limit_map = devm_kmalloc_array(dev,
+ len / 2, sizeof(*gpio_charger->current_limit_map), GFP_KERNEL);
+ if (!gpio_charger->current_limit_map)
+ return -ENOMEM;
+
+ gpio_charger->current_limit_map_size = len / 2;
+
+ len = device_property_read_u32_array(dev, "charge-current-limit-mapping",
+ (u32*) gpio_charger->current_limit_map, len);
+ if (len < 0)
+ return len;
+
+ for (i=0; i < gpio_charger->current_limit_map_size; i++) {
+ if (gpio_charger->current_limit_map[i].limit_ua > cur_limit) {
+ dev_err(dev, "charge-current-limit-mapping not sorted by current in descending order\n");
+ return -EINVAL;
+ }
+
+ cur_limit = gpio_charger->current_limit_map[i].limit_ua;
+ }
+
+ /* default to smallest current limitation for safety reasons */
+ len = gpio_charger->current_limit_map_size - 1;
+ set_charge_current_limit(gpio_charger,
+ gpio_charger->current_limit_map[len].limit_ua);
+
+ return 0;
+}
+
/*
* The entries will be overwritten by driver's probe routine depending
* on the available features. This list ensures, that the array is big
@@ -119,6 +245,7 @@ static int gpio_charger_get_irq(struct device *dev, void *dev_id,
static enum power_supply_property gpio_charger_properties[] = {
POWER_SUPPLY_PROP_ONLINE,
POWER_SUPPLY_PROP_STATUS,
+ POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX,
};
static int gpio_charger_probe(struct platform_device *pdev)
@@ -141,6 +268,7 @@ static int gpio_charger_probe(struct platform_device *pdev)
gpio_charger = devm_kzalloc(dev, sizeof(*gpio_charger), GFP_KERNEL);
if (!gpio_charger)
return -ENOMEM;
+ gpio_charger->dev = dev;
/*
* This will fetch a GPIO descriptor from device tree, ACPI or
@@ -167,10 +295,22 @@ static int gpio_charger_probe(struct platform_device *pdev)
num_props++;
}
+ ret = init_charge_current_limit(dev, gpio_charger);
+ if (ret < 0)
+ return ret;
+ if (gpio_charger->current_limit_map) {
+ gpio_charger_properties[num_props] =
+ POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX;
+ num_props++;
+ }
+
charger_desc = &gpio_charger->charger_desc;
charger_desc->properties = gpio_charger_properties;
charger_desc->num_properties = num_props;
charger_desc->get_property = gpio_charger_get_property;
+ charger_desc->set_property = gpio_charger_set_property;
+ charger_desc->property_is_writeable =
+ gpio_charger_property_is_writeable;
psy_cfg.of_node = dev->of_node;
psy_cfg.drv_data = gpio_charger;