mfd: ab8500-gpadc: Add runtime pm support

Add runtime pm support to speed up multiple ADC reads in a row.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Jonas Aaberg <jonas.aberg@stericsson.com>
Reviewed-by: Ulf HANSSON <ulf.hansson@stericsson.com>

1 files changed, 64 insertions, 6 deletions

diff --git a/drivers/mfd/ab8500-gpadc.c b/drivers/mfd/ab8500-gpadc.c
index 61b176fc457b..580f1008d67a 100644
--- a/drivers/mfd/ab8500-gpadc.c
+++ b/drivers/mfd/ab8500-gpadc.c
@@ -12,6 +12,7 @@
 #include <linux/interrupt.h>
 #include <linux/spinlock.h>
 #include <linux/delay.h>
+#include <linux/pm_runtime.h>
 #include <linux/platform_device.h>
 #include <linux/completion.h>
 #include <linux/regulator/consumer.h>
@@ -82,6 +83,9 @@
 /* This is used to not lose precision when dividing to get gain and offset */
 #define CALIB_SCALE                     1000
 
+/* Time in ms before disabling regulator */
+#define GPADC_AUDOSUSPEND_DELAY         1
+
 enum cal_channels {
         ADC_INPUT_VMAIN = 0,
         ADC_INPUT_BTEMP,
@@ -282,8 +286,9 @@ int ab8500_gpadc_read_raw(struct ab8500_gpadc *gpadc, u8 channel)
                 return -ENODEV;
 
         mutex_lock(&gpadc->ab8500_gpadc_lock);
+
         /* Enable VTVout LDO this is required for GPADC */
-        regulator_enable(gpadc->regu);
+        pm_runtime_get_sync(gpadc->dev);
 
         /* Check if ADC is not busy, lock and proceed */
         do {
@@ -397,8 +402,10 @@ int ab8500_gpadc_read_raw(struct ab8500_gpadc *gpadc, u8 channel)
                 dev_err(gpadc->dev, "gpadc_conversion: disable gpadc failed\n");
                 goto out;
         }
-        /* Disable VTVout LDO this is required for GPADC */
-        regulator_disable(gpadc->regu);
+
+        pm_runtime_mark_last_busy(gpadc->dev);
+        pm_runtime_put_autosuspend(gpadc->dev);
+
         mutex_unlock(&gpadc->ab8500_gpadc_lock);
 
         return (high_data << 8) | low_data;
@@ -412,7 +419,9 @@ out:
          */
         (void) abx500_set_register_interruptible(gpadc->dev, AB8500_GPADC,
                 AB8500_GPADC_CTRL1_REG, DIS_GPADC);
-        regulator_disable(gpadc->regu);
+
+        pm_runtime_put(gpadc->dev);
+
         mutex_unlock(&gpadc->ab8500_gpadc_lock);
         dev_err(gpadc->dev,
                 "gpadc_conversion: Failed to AD convert channel %d\n", channel);
@@ -571,6 +580,30 @@ static void ab8500_gpadc_read_calibration_data(struct ab8500_gpadc *gpadc)
                 gpadc->cal_data[ADC_INPUT_VBAT].offset);
 }
 
+static int ab8500_gpadc_runtime_suspend(struct device *dev)
+{
+        struct ab8500_gpadc *gpadc = dev_get_drvdata(dev);
+
+        regulator_disable(gpadc->regu);
+        return 0;
+}
+
+static int ab8500_gpadc_runtime_resume(struct device *dev)
+{
+        struct ab8500_gpadc *gpadc = dev_get_drvdata(dev);
+
+        regulator_enable(gpadc->regu);
+        return 0;
+}
+
+static int ab8500_gpadc_runtime_idle(struct device *dev)
+{
+        struct ab8500_gpadc *gpadc = dev_get_drvdata(dev);
+
+        pm_runtime_suspend(dev);
+        return 0;
+}
+
 static int ab8500_gpadc_probe(struct platform_device *pdev)
 {
         int ret = 0;
@@ -615,6 +648,16 @@ static int ab8500_gpadc_probe(struct platform_device *pdev)
                 dev_err(gpadc->dev, "failed to get vtvout LDO\n");
                 goto fail_irq;
         }
+
+        platform_set_drvdata(pdev, gpadc);
+
+        regulator_enable(gpadc->regu);
+
+        pm_runtime_set_autosuspend_delay(gpadc->dev, GPADC_AUDOSUSPEND_DELAY);
+        pm_runtime_use_autosuspend(gpadc->dev);
+        pm_runtime_set_active(gpadc->dev);
+        pm_runtime_enable(gpadc->dev);
+
         ab8500_gpadc_read_calibration_data(gpadc);
         list_add_tail(&gpadc->node, &ab8500_gpadc_list);
         dev_dbg(gpadc->dev, "probe success\n");
@@ -635,19 +678,34 @@ static int ab8500_gpadc_remove(struct platform_device *pdev)
         list_del(&gpadc->node);
         /* remove interrupt  - completion of Sw ADC conversion */
         free_irq(gpadc->irq, gpadc);
-        /* disable VTVout LDO that is being used by GPADC */
-        regulator_put(gpadc->regu);
+
+        pm_runtime_get_sync(gpadc->dev);
+        pm_runtime_disable(gpadc->dev);
+
+        regulator_disable(gpadc->regu);
+
+        pm_runtime_set_suspended(gpadc->dev);
+
+        pm_runtime_put_noidle(gpadc->dev);
+
         kfree(gpadc);
         gpadc = NULL;
         return 0;
 }
 
+static const struct dev_pm_ops ab8500_gpadc_pm_ops = {
+        SET_RUNTIME_PM_OPS(ab8500_gpadc_runtime_suspend,
+                           ab8500_gpadc_runtime_resume,
+                           ab8500_gpadc_runtime_idle)
+};
+
 static struct platform_driver ab8500_gpadc_driver = {
         .probe = ab8500_gpadc_probe,
         .remove = ab8500_gpadc_remove,
         .driver = {
                 .name = "ab8500-gpadc",
                 .owner = THIS_MODULE,
+                .pm = &ab8500_gpadc_pm_ops,
         },
 };