sony-laptop: add camera enable/disable parameter, better handle possible infinite loop

Use a parameter to enable/disable motion eye camera (for C1VE/C1VN models)
controls and avoid entering an infinite loop if the camera is not present
and the HW doesn't answer as we expect on io commands.

Signed-off-by: Mattia Dongili <malattia@linux.it>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 36 insertions, 15 deletions

diff --git a/drivers/misc/sony-laptop.c b/drivers/misc/sony-laptop.c
index 8cc041182a11..09e75390ac98 100644
--- a/drivers/misc/sony-laptop.c
+++ b/drivers/misc/sony-laptop.c
@@ -107,6 +107,12 @@ module_param(mask, ulong, 0644);
 MODULE_PARM_DESC(mask,
                  "set this to the mask of event you want to enable (see doc)");
 
+static int camera;              /* = 0 */
+module_param(camera, int, 0444);
+MODULE_PARM_DESC(camera,
+                 "set this to 1 to enable Motion Eye camera controls "
+                 "(only use it if you have a C1VE or C1VN model)");
+
 #ifdef CONFIG_SONY_LAPTOP_OLD
 static int minor = -1;
 module_param(minor, int, 0);
@@ -1226,29 +1232,39 @@ static int sony_pic_camera_ready(void)
         return (v != 0xff && (v & SONYPI_CAMERA_STATUS_READY));
 }
 
-static void sony_pic_camera_off(void)
+static int sony_pic_camera_off(void)
 {
+        if (!camera) {
+                printk(KERN_WARNING DRV_PFX "camera control not enabled\n");
+                return -ENODEV;
+        }
+
         wait_on_command(sony_pic_call3(0x90, SONYPI_CAMERA_PICTURE,
                                 SONYPI_CAMERA_MUTE_MASK),
                         ITERATIONS_SHORT);
 
-        if (!spic_dev.camera_power)
-                return;
-
-        sony_pic_call2(0x91, 0);
-        spic_dev.camera_power = 0;
+        if (spic_dev.camera_power) {
+                sony_pic_call2(0x91, 0);
+                spic_dev.camera_power = 0;
+        }
+        return 0;
 }
 
-static void sony_pic_camera_on(void)
+static int sony_pic_camera_on(void)
 {
-        int i, j;
+        int i, j, x;
+
+        if (!camera) {
+                printk(KERN_WARNING DRV_PFX "camera control not enabled\n");
+                return -ENODEV;
+        }
 
         if (spic_dev.camera_power)
-                return;
+                return 0;
 
         for (j = 5; j > 0; j--) {
 
-                while (sony_pic_call2(0x91, 0x1))
+                for (x = 0; x < 100 && sony_pic_call2(0x91, 0x1); x++)
                         msleep(10);
                 sony_pic_call1(0x93);
 
@@ -1262,8 +1278,8 @@ static void sony_pic_camera_on(void)
         }
 
         if (j == 0) {
-                printk(KERN_WARNING "sonypi: failed to power on camera\n");
-                return;
+                printk(KERN_WARNING DRV_PFX "failed to power on camera\n");
+                return -ENODEV;
         }
 
         wait_on_command(sony_pic_call3(0x90, SONYPI_CAMERA_CONTROL,
@@ -1271,6 +1287,7 @@ static void sony_pic_camera_on(void)
                         ITERATIONS_SHORT);
 
         spic_dev.camera_power = 1;
+        return 0;
 }
 
 static ssize_t sony_pic_camerapower_store(struct device *dev,
@@ -1278,14 +1295,18 @@ static ssize_t sony_pic_camerapower_store(struct device *dev,
                 const char *buffer, size_t count)
 {
         unsigned long value;
+        int result;
         if (count > 31)
                 return -EINVAL;
 
         value = simple_strtoul(buffer, NULL, 10);
         if (value)
-                sony_pic_camera_on();
+                result = sony_pic_camera_on();
         else
-                sony_pic_camera_off();
+                result = sony_pic_camera_off();
+
+        if (result)
+                return result;
 
         return count;
 }
@@ -1662,7 +1683,7 @@ static int sonypi_compat_init(void)
                 goto err_free_kfifo;
         }
         if (minor == -1)
-                printk(KERN_INFO "sonypi: device allocated minor is %d\n",
+                printk(KERN_INFO DRV_PFX "device allocated minor is %d\n",
                        sonypi_misc_device.minor);
 
         return 0;