input: synaptics_i2c_rmi4: Add low power mode

Enable regulators to go into low power mode when
device enters suspend, to save power.  In resume,
return regulators to full power.

Change-Id: I6f5a6d398732b2e23aeba81b3569ae2c081f31e5
Signed-off-by: Amy Maloche <amaloche@codeaurora.org>
diff --git a/drivers/input/touchscreen/synaptics_i2c_rmi4.c b/drivers/input/touchscreen/synaptics_i2c_rmi4.c
index 417ef83..f958efe 100644
--- a/drivers/input/touchscreen/synaptics_i2c_rmi4.c
+++ b/drivers/input/touchscreen/synaptics_i2c_rmi4.c
@@ -91,6 +91,10 @@
 
 static int synaptics_rmi4_reset_device(struct synaptics_rmi4_data *rmi4_data);
 
+#ifdef CONFIG_PM
+static int synaptics_rmi4_suspend(struct device *dev);
+
+static int synaptics_rmi4_resume(struct device *dev);
 #ifdef CONFIG_HAS_EARLYSUSPEND
 static ssize_t synaptics_rmi4_full_pm_cycle_show(struct device *dev,
 		struct device_attribute *attr, char *buf);
@@ -101,10 +105,7 @@
 static void synaptics_rmi4_early_suspend(struct early_suspend *h);
 
 static void synaptics_rmi4_late_resume(struct early_suspend *h);
-
-static int synaptics_rmi4_suspend(struct device *dev);
-
-static int synaptics_rmi4_resume(struct device *dev);
+#endif
 #endif
 
 static ssize_t synaptics_rmi4_f01_reset_store(struct device *dev,
@@ -1816,7 +1817,7 @@
 				RMI4_VTG_MIN_UV, RMI4_VTG_MAX_UV);
 			if (retval) {
 				dev_err(&rmi4_data->i2c_client->dev,
-					"regulator set_vtg failed retval=%d\n",
+					"regulator set_vtg failed retval =%d\n",
 					retval);
 				goto err_set_vtg_vdd;
 			}
@@ -1839,7 +1840,7 @@
 				RMI4_I2C_VTG_MIN_UV, RMI4_I2C_VTG_MAX_UV);
 			if (retval) {
 				dev_err(&rmi4_data->i2c_client->dev,
-					"reg set i2c vtg failed retval=%d\n",
+					"reg set i2c vtg failed retval =%d\n",
 					retval);
 			goto err_set_vtg_i2c;
 			}
@@ -2470,6 +2471,75 @@
 }
 #endif
 
+static int synaptics_rmi4_regulator_lpm(struct synaptics_rmi4_data *rmi4_data,
+						bool on)
+{
+	int retval;
+
+	if (on == false)
+		goto regulator_hpm;
+
+	retval = reg_set_optimum_mode_check(rmi4_data->vdd, RMI4_LPM_LOAD_UA);
+	if (retval < 0) {
+		dev_err(&rmi4_data->i2c_client->dev,
+			"Regulator vcc_ana set_opt failed rc=%d\n",
+			retval);
+		goto fail_regulator_lpm;
+	}
+
+	if (rmi4_data->board->i2c_pull_up) {
+		retval = reg_set_optimum_mode_check(rmi4_data->vcc_i2c,
+			RMI4_I2C_LOAD_UA);
+		if (retval < 0) {
+			dev_err(&rmi4_data->i2c_client->dev,
+				"Regulator vcc_i2c set_opt failed rc=%d\n",
+				retval);
+			goto fail_regulator_lpm;
+		}
+	}
+
+	return 0;
+
+regulator_hpm:
+
+	retval = reg_set_optimum_mode_check(rmi4_data->vdd,
+				RMI4_ACTIVE_LOAD_UA);
+	if (retval < 0) {
+		dev_err(&rmi4_data->i2c_client->dev,
+			"Regulator vcc_ana set_opt failed rc=%d\n",
+			retval);
+		goto fail_regulator_hpm;
+	}
+
+	if (rmi4_data->board->i2c_pull_up) {
+		retval = reg_set_optimum_mode_check(rmi4_data->vcc_i2c,
+			RMI4_I2C_LOAD_UA);
+		if (retval < 0) {
+			dev_err(&rmi4_data->i2c_client->dev,
+				"Regulator vcc_i2c set_opt failed rc=%d\n",
+				retval);
+			goto fail_regulator_hpm;
+		}
+	}
+
+	return 0;
+
+fail_regulator_lpm:
+	reg_set_optimum_mode_check(rmi4_data->vdd, RMI4_ACTIVE_LOAD_UA);
+	if (rmi4_data->board->i2c_pull_up)
+		reg_set_optimum_mode_check(rmi4_data->vcc_i2c,
+						RMI4_I2C_LOAD_UA);
+
+	return retval;
+
+fail_regulator_hpm:
+	reg_set_optimum_mode_check(rmi4_data->vdd, RMI4_LPM_LOAD_UA);
+	if (rmi4_data->board->i2c_pull_up)
+		reg_set_optimum_mode_check(rmi4_data->vcc_i2c,
+						RMI4_I2C_LPM_LOAD_UA);
+	return retval;
+}
+
  /**
  * synaptics_rmi4_suspend()
  *
@@ -2483,6 +2553,7 @@
 static int synaptics_rmi4_suspend(struct device *dev)
 {
 	struct synaptics_rmi4_data *rmi4_data = dev_get_drvdata(dev);
+	int retval;
 
 	if (!rmi4_data->sensor_sleep) {
 		rmi4_data->touch_stopped = true;
@@ -2491,6 +2562,12 @@
 		synaptics_rmi4_sensor_sleep(rmi4_data);
 	}
 
+	retval = synaptics_rmi4_regulator_lpm(rmi4_data, true);
+	if (retval < 0) {
+		dev_err(dev, "failed to enter low power mode\n");
+		return retval;
+	}
+
 	return 0;
 }
 
@@ -2507,6 +2584,13 @@
 static int synaptics_rmi4_resume(struct device *dev)
 {
 	struct synaptics_rmi4_data *rmi4_data = dev_get_drvdata(dev);
+	int retval;
+
+	retval = synaptics_rmi4_regulator_lpm(rmi4_data, false);
+	if (retval < 0) {
+		dev_err(dev, "failed to enter active power mode\n");
+		return retval;
+	}
 
 	synaptics_rmi4_sensor_wake(rmi4_data);
 	rmi4_data->touch_stopped = false;