From: makarand.karvekar <makarand.karvekar@motorola.com>
Date: Sun, 31 Oct 2010 23:59:20 +0000 (-0500)
Subject: misc: l3g4200d: fix power down issue
X-Git-Tag: firefly_0821_release~9834^2~393
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=f6c9e764b56f1a7f986bb573d211398187dbf55a;p=firefly-linux-kernel-4.4.55.git

misc: l3g4200d: fix power down issue

only clean PD bit in CTRL_REG1 when power off
and restore it when power on

Author: Ken Hu <jian-wu.hu@motorola.com>

Change-Id: I50c6ba1a77d8a347c63ffb7518182c7ac1a1d738
Signed-off-by: makarand.karvekar <makarand.karvekar@motorola.com>
---

diff --git a/drivers/misc/l3g4200d.c b/drivers/misc/l3g4200d.c
index 15f65569060d..311ac744aea4 100644
--- a/drivers/misc/l3g4200d.c
+++ b/drivers/misc/l3g4200d.c
@@ -60,8 +60,7 @@
 #define L3G4200D_INTERRUPT_THRESH_Z_L	0x37
 #define L3G4200D_INTERRUPT_DURATION	0x38
 
-#define PM_OFF				0x00
-#define PM_NORMAL			0x20
+#define PM_MASK                         0x08
 #define ENABLE_ALL_AXES			0x07
 
 #define I2C_RETRY_DELAY			5
@@ -219,7 +218,15 @@ static int l3g4200d_hw_init(struct l3g4200d_data *gyro)
 static void l3g4200d_device_power_off(struct l3g4200d_data *gyro)
 {
 	int err;
-	u8 buf[2] = {L3G4200D_CTRL_REG1, PM_OFF};
+	u8 buf[2] = {L3G4200D_CTRL_REG1,0 };
+
+	err = l3g4200d_i2c_read(gyro, buf, 1);
+	if (err < 0){
+		dev_err(&gyro->client->dev, "read register control_1 failed\n");
+                return ;
+        }
+        buf[1] = buf[0] & ~PM_MASK;
+        buf[0] = L3G4200D_CTRL_REG1;
 
 	err = l3g4200d_i2c_write(gyro, buf, 1);
 	if (err < 0)
@@ -234,6 +241,7 @@ static void l3g4200d_device_power_off(struct l3g4200d_data *gyro)
 static int l3g4200d_device_power_on(struct l3g4200d_data *gyro)
 {
 	int err;
+	u8 buf[2] = {L3G4200D_CTRL_REG1, 0};
 
 	if (gyro->regulator) {
 		err = regulator_enable(gyro->regulator);
@@ -248,7 +256,15 @@ static int l3g4200d_device_power_on(struct l3g4200d_data *gyro)
 			return err;
 		}
 	}
+	err = l3g4200d_i2c_read(gyro, buf, 1);
+	if (err < 0)
+		dev_err(&gyro->client->dev, "read register control_1 failed\n");
+        buf[1] = buf[0] | PM_MASK;
+        buf[0] = L3G4200D_CTRL_REG1;
 
+	err = l3g4200d_i2c_write(gyro, buf, 1);
+	if (err < 0)
+		dev_err(&gyro->client->dev, "soft power on failed\n");
 	return 0;
 }