[media] soc_camera: Add the ability to bind regulators to soc_camedra devices

In certain machines, camera devices are supplied directly
by a number of regulators. This patch add the ability to drive
these regulators directly by the soc_camera driver.

Signed-off-by: Alberto Panizzo <maramaopercheseimorto@gmail.com>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

2 files changed, 70 insertions, 21 deletions

diff --git a/drivers/media/video/soc_camera.c b/drivers/media/video/soc_camera.c
index aba4ce92a86b..a66811b43710 100644
--- a/drivers/media/video/soc_camera.c
+++ b/drivers/media/video/soc_camera.c
@@ -24,6 +24,7 @@
 #include <linux/mutex.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
 #include <linux/slab.h>
 #include <linux/pm_runtime.h>
 #include <linux/vmalloc.h>
@@ -43,6 +44,51 @@ static LIST_HEAD(hosts);
 static LIST_HEAD(devices);
 static DEFINE_MUTEX(list_lock);         /* Protects the list of hosts */
 
+static int soc_camera_power_set(struct soc_camera_device *icd,
+                                struct soc_camera_link *icl,
+                                int power_on)
+{
+        int ret;
+
+        if (power_on) {
+                ret = regulator_bulk_enable(icl->num_regulators,
+                                            icl->regulators);
+                if (ret < 0) {
+                        dev_err(&icd->dev, "Cannot enable regulators\n");
+                        return ret;
+                }
+
+                if (icl->power)
+                        ret = icl->power(icd->pdev, power_on);
+                if (ret < 0) {
+                        dev_err(&icd->dev,
+                                "Platform failed to power-on the camera.\n");
+
+                        regulator_bulk_disable(icl->num_regulators,
+                                               icl->regulators);
+                        return ret;
+                }
+        } else {
+                ret = 0;
+                if (icl->power)
+                        ret = icl->power(icd->pdev, 0);
+                if (ret < 0) {
+                        dev_err(&icd->dev,
+                                "Platform failed to power-off the camera.\n");
+                        return ret;
+                }
+
+                ret = regulator_bulk_disable(icl->num_regulators,
+                                             icl->regulators);
+                if (ret < 0) {
+                        dev_err(&icd->dev, "Cannot disable regulators\n");
+                        return ret;
+                }
+        }
+
+        return 0;
+}
+
 const struct soc_camera_format_xlate *soc_camera_xlate_by_fourcc(
         struct soc_camera_device *icd, unsigned int fourcc)
 {
@@ -369,11 +415,9 @@ static int soc_camera_open(struct file *file)
                         },
                 };
 
-                if (icl->power) {
-                        ret = icl->power(icd->pdev, 1);
-                        if (ret < 0)
-                                goto epower;
-                }
+                ret = soc_camera_power_set(icd, icl, 1);
+                if (ret < 0)
+                        goto epower;
 
                 /* The camera could have been already on, try to reset */
                 if (icl->reset)
@@ -417,8 +461,7 @@ esfmt:
 eresume:
         ici->ops->remove(icd);
 eiciadd:
-        if (icl->power)
-                icl->power(icd->pdev, 0);
+        soc_camera_power_set(icd, icl, 0);
 epower:
         icd->use_count--;
         module_put(ici->ops->owner);
@@ -440,8 +483,7 @@ static int soc_camera_close(struct file *file)
 
                 ici->ops->remove(icd);
 
-                if (icl->power)
-                        icl->power(icd->pdev, 0);
+                soc_camera_power_set(icd, icl, 0);
         }
 
         if (icd->streamer == file)
@@ -908,14 +950,14 @@ static int soc_camera_probe(struct device *dev)
 
         dev_info(dev, "Probing %s\n", dev_name(dev));
 
-        if (icl->power) {
-                ret = icl->power(icd->pdev, 1);
-                if (ret < 0) {
-                        dev_err(dev,
-                                "Platform failed to power-on the camera.\n");
-                        goto epower;
-                }
-        }
+        ret = regulator_bulk_get(icd->pdev, icl->num_regulators,
+                                 icl->regulators);
+        if (ret < 0)
+                goto ereg;
+
+        ret = soc_camera_power_set(icd, icl, 1);
+        if (ret < 0)
+                goto epower;
 
         /* The camera could have been already on, try to reset */
         if (icl->reset)
@@ -994,8 +1036,7 @@ static int soc_camera_probe(struct device *dev)
 
         ici->ops->remove(icd);
 
-        if (icl->power)
-                icl->power(icd->pdev, 0);
+        soc_camera_power_set(icd, icl, 0);
 
         mutex_unlock(&icd->video_lock);
 
@@ -1017,9 +1058,10 @@ eadddev:
 evdc:
         ici->ops->remove(icd);
 eadd:
-        if (icl->power)
-                icl->power(icd->pdev, 0);
+        soc_camera_power_set(icd, icl, 0);
 epower:
+        regulator_bulk_free(icl->num_regulators, icl->regulators);
+ereg:
         return ret;
 }
 
@@ -1052,6 +1094,8 @@ static int soc_camera_remove(struct device *dev)
         }
         soc_camera_free_user_formats(icd);
 
+        regulator_bulk_free(icl->num_regulators, icl->regulators);
+
         return 0;
 }
 
diff --git a/include/media/soc_camera.h b/include/media/soc_camera.h
index 86e3631764ef..9386db829fb7 100644
--- a/include/media/soc_camera.h
+++ b/include/media/soc_camera.h
@@ -97,6 +97,7 @@ struct soc_camera_host_ops {
 #define SOCAM_SENSOR_INVERT_DATA        (1 << 4)
 
 struct i2c_board_info;
+struct regulator_bulk_data;
 
 struct soc_camera_link {
         /* Camera bus id, used to match a camera and a bus */
@@ -108,6 +109,10 @@ struct soc_camera_link {
         const char *module_name;
         void *priv;
 
+        /* Optional regulators that have to be managed on power on/off events */
+        struct regulator_bulk_data *regulators;
+        int num_regulators;
+
         /*
          * For non-I2C devices platform platform has to provide methods to
          * add a device to the system and to remove