MFD: tc35892: Optimize power save settings for suspend

Compared to HSI GPIO V3.1, register 0x82 is set with a different value

0x82 = 0xE (HSI GPIO V3.1)
0x82 = 0xF (on android)

In case of android, it seems that GPIO reset should be applied to reach 13uA
of consumption on TC35892 when AP in DeepSleep

Change-Id: I64eaa4304fcd9f71546cadba0aa703c91b6075df
Signed-off-by: David Paris <david.paris-nonst@stericsson.com>
Signed-off-by: Jonas Aaberg <jonas.aberg@stericsson.com>

1 files changed, 120 insertions, 11 deletions

diff --git a/drivers/mfd/tc35892.c b/drivers/mfd/tc35892.c
index 33d44bbc731..c997a4b67aa 100644
--- a/drivers/mfd/tc35892.c
+++ b/drivers/mfd/tc35892.c
@@ -325,17 +325,112 @@ static int __devexit tc35892_remove(struct i2c_client *client)
 }
 
 #ifdef CONFIG_PM
+
+static u32 sleep_regs[] = {
+	TC35892_IOPC0_L,
+	TC35892_IOPC0_H,
+	TC35892_IOPC1_L,
+	TC35892_IOPC1_H,
+	TC35892_IOPC2_L,
+	TC35892_IOPC2_H,
+	TC35892_DRIVE0_L,
+	TC35892_DRIVE0_H,
+	TC35892_DRIVE1_L,
+	TC35892_DRIVE1_H,
+	TC35892_DRIVE2_L,
+	TC35892_DRIVE2_H,
+	TC35892_DRIVE3,
+	TC35892_GPIODATA0,
+	TC35892_GPIOMASK0,
+	TC35892_GPIODATA1,
+	TC35892_GPIOMASK1,
+	TC35892_GPIODATA2,
+	TC35892_GPIOMASK2,
+	TC35892_GPIODIR0,
+	TC35892_GPIODIR1,
+	TC35892_GPIODIR2,
+	TC35892_GPIOIE0,
+	TC35892_GPIOIE1,
+	TC35892_GPIOIE2,
+	TC35892_RSTCTRL,
+	TC35892_CLKCFG,
+};
+
+static u8 sleep_regs_val[] = {
+	0x00,		/* TC35892_IOPC0_L */
+	0x00,		/* TC35892_IOPC0_H */
+	0x00,		/* TC35892_IOPC1_L */
+	0x00,		/* TC35892_IOPC1_H */
+	0x00,		/* TC35892_IOPC2_L */
+	0x00,		/* TC35892_IOPC2_H */
+	0xff,		/* TC35892_DRIVE0_L */
+	0xff,		/* TC35892_DRIVE0_H */
+	0xff,		/* TC35892_DRIVE1_L */
+	0xff,		/* TC35892_DRIVE1_H */
+	0xff,		/* TC35892_DRIVE2_L */
+	0xff,		/* TC35892_DRIVE2_H */
+	0x0f,		/* TC35892_DRIVE3 */
+	0x80,		/* TC35892_GPIODATA0 */
+	0x80,		/* TC35892_GPIOMASK0 */
+	0x80,		/* TC35892_GPIODATA1 */
+	0x80,		/* TC35892_GPIOMASK1 */
+	0x06,		/* TC35892_GPIODATA2 */
+	0x06,		/* TC35892_GPIOMASK2 */
+	0xf0,		/* TC35892_GPIODIR0 */
+	0xe0,		/* TC35892_GPIODIR1 */
+	0xee,		/* TC35892_GPIODIR2 */
+	0x0f,		/* TC35892_GPIOIE0 */
+	0x1f,		/* TC35892_GPIOIE1 */
+	0x11,		/* TC35892_GPIOIE2 */
+	0x0f,		/* TC35892_RSTCTRL */
+	0xb0		/* TC35892_CLKCFG */
+
+};
+
+static u8 sleep_regs_backup[ARRAY_SIZE(sleep_regs)];
+
 static int tc35892_suspend(struct device *dev)
 {
 	struct tc35892 *tc35892 = dev_get_drvdata(dev);
 	struct i2c_client *client = tc35892->i2c;
 	int ret = 0;
-
-	/* put the system to sleep mode */
-	if (!device_may_wakeup(&client->dev))
-		ret = tc35892_reg_write(tc35892, TC35892_CLKMODE,
-				TC35892_CLKMODE_MODCTL_SLEEP);
-
+	int i, j;
+	int val;
+
+	/* Put the system to sleep mode */
+	if (!device_may_wakeup(&client->dev)) {
+		for (i = 0; i < ARRAY_SIZE(sleep_regs); i++) {
+			val = tc35892_reg_read(tc35892,
+					       sleep_regs[i]);
+			if (val < 0)
+				goto out;
+
+			sleep_regs_backup[i] = (u8) (val & 0xff);
+		}
+
+		for (i = 0; i < ARRAY_SIZE(sleep_regs); i++) {
+			ret = tc35892_reg_write(tc35892,
+					  sleep_regs[i],
+					  sleep_regs_val[i]);
+			if (ret < 0)
+				goto fail;
+
+		}
+
+		ret = tc35892_reg_write(tc35892,
+					TC35892_CLKMODE,
+					TC35892_CLKMODE_MODCTL_SLEEP);
+	}
+out:
+	return ret;
+fail:
+	for (j = 0; j <= i; j++) {
+		ret = tc35892_reg_write(tc35892,
+					sleep_regs[i],
+					sleep_regs_backup[i]);
+		if (ret < 0)
+			break;
+	}
 	return ret;
 }
 
@@ -344,16 +439,30 @@ static int tc35892_resume(struct device *dev)
 	struct tc35892 *tc35892 = dev_get_drvdata(dev);
 	struct i2c_client *client = tc35892->i2c;
 	int ret = 0;
+	int i;
 
-	/* enable the system into operation */
+	/* Enable the system into operation */
 	if (!device_may_wakeup(&client->dev))
-		ret = tc35892_reg_write(tc35892, TC35892_CLKMODE,
-				TC35892_CLKMODE_MODCTL_OPERATION);
-
+	{
+		ret = tc35892_reg_write(tc35892,
+					TC35892_CLKMODE,
+					TC35892_CLKMODE_MODCTL_OPERATION);
+		if (ret < 0)
+			goto out;
+
+		for (i = 0; i < ARRAY_SIZE(sleep_regs); i++) {
+			ret = tc35892_reg_write(tc35892,
+						sleep_regs[i],
+						sleep_regs_backup[i]);
+			/* Not much to do here if we fail */
+			if (ret < 0)
+				break;
+		}
+	}
+out:
 	return ret;
 }
 
-
 static const struct dev_pm_ops tc35892_dev_pm_ops = {
 	.suspend = tc35892_suspend,
 	.resume  = tc35892_resume,