pm2301-charger: Add pm_runtime_resume & pm_runtime_suspend

To optimize the current consumption we use pm_runtime autosuspend
functions which execute the pm_runtime_suspend after a delay of
inactivity on the other hand we use pm_runtime_resume every time
we receive an interruption to wake up the pm2301.

Signed-off-by: M BenZoubeir <[e-mail]>
Signed-off-by: Lee Jones <[e-mail]>
Reviewed-by: Philippe LANGLAIS <[e-mail]>

drivers/power/pm2301_charger.c

···
 #include <linux/mfd/abx500/ux500_chargalg.h>
 #include <linux/pm2301_charger.h>
 #include <linux/gpio.h>
+#include <linux/pm_runtime.h>
 
 #include "pm2301_charger.h"
 
···
 		struct pm2xxx_charger, ac_chg)
 #define SLEEP_MIN		50
 #define SLEEP_MAX		100
+#define PM2XXX_AUTOSUSPEND_DELAY 500
 
 static int pm2xxx_interrupt_registers[] = {
 	PM2XXX_REG_INT1,
···
 	struct pm2xxx_interrupts *interrupt = pm2->pm2_int;
 	int i;
 
+	/* wake up the device */
+	pm_runtime_get_sync(pm2->dev);
+
 	do {
 		for (i = 0; i < PM2XXX_NUM_INT_REG; i++) {
 			pm2xxx_reg_read(pm2,
···
 				interrupt->handler[i](pm2, interrupt->reg[i]);
 		}
 	} while (gpio_get_value(pm2->pdata->gpio_irq_number) == 0);
+
+	pm_runtime_mark_last_busy(pm2->dev);
+	pm_runtime_put_autosuspend(pm2->dev);
 
 	return IRQ_HANDLED;
 }
···
 	return 0;
 }
 
+#ifdef CONFIG_PM
+static int  pm2xxx_runtime_suspend(struct device *dev)
+{
+	struct i2c_client *pm2xxx_i2c_client = to_i2c_client(dev);
+	struct pm2xxx_charger *pm2;
+	int ret = 0;
+
+	pm2 = (struct pm2xxx_charger *)i2c_get_clientdata(pm2xxx_i2c_client);
+	if (!pm2) {
+		dev_err(pm2->dev, "no pm2xxx_charger data supplied\n");
+		ret = -EINVAL;
+		return ret;
+	}
+
+	clear_lpn_pin(pm2);
+
+	return ret;
+}
+
+static int  pm2xxx_runtime_resume(struct device *dev)
+{
+	struct i2c_client *pm2xxx_i2c_client = to_i2c_client(dev);
+	struct pm2xxx_charger *pm2;
+	int ret = 0;
+
+	pm2 = (struct pm2xxx_charger *)i2c_get_clientdata(pm2xxx_i2c_client);
+	if (!pm2) {
+		dev_err(pm2->dev, "no pm2xxx_charger data supplied\n");
+		ret = -EINVAL;
+		return ret;
+	}
+
+	if (gpio_is_valid(pm2->lpn_pin) && gpio_get_value(pm2->lpn_pin) == 0)
+		set_lpn_pin(pm2);
+
+	return ret;
+}
+
+static const struct dev_pm_ops pm2xxx_pm_ops = {
+	.runtime_suspend = pm2xxx_runtime_suspend,
+	.runtime_resume = pm2xxx_runtime_resume,
+};
+#define  PM2XXX_PM_OPS (&pm2xxx_pm_ops)
+#else
+#define  PM2XXX_PM_OPS  NULL
+#endif
+
 static int pm2xxx_wall_charger_probe(struct i2c_client *i2c_client,
 		const struct i2c_device_id *id)
 {
···
 			gpio_to_irq(pm2->pdata->gpio_irq_number), ret);
 		goto unregister_pm2xxx_charger;
 	}
+
+	ret = pm_runtime_set_active(pm2->dev);
+	if (ret)
+		dev_err(pm2->dev, "set active Error\n");
+
+	pm_runtime_enable(pm2->dev);
+	pm_runtime_set_autosuspend_delay(pm2->dev, PM2XXX_AUTOSUSPEND_DELAY);
+	pm_runtime_use_autosuspend(pm2->dev);
+	pm_runtime_resume(pm2->dev);
+
 	/* pm interrupt can wake up system */
 	ret = enable_irq_wake(gpio_to_irq(pm2->pdata->gpio_irq_number));
 	if (ret) {
···
 {
 	struct pm2xxx_charger *pm2 = i2c_get_clientdata(i2c_client);
 
+	/* Disable pm_runtime */
+	pm_runtime_disable(pm2->dev);
 	/* Disable AC charging */
 	pm2xxx_charger_ac_en(&pm2->ac_chg, false, 0, 0);
 
···
 	.driver = {
 		.name = "pm2xxx-wall_charger",
 		.owner = THIS_MODULE,
+		.pm = PM2XXX_PM_OPS,
 	},
 	.id_table = pm2xxx_id,
 };