1 files changed, 36 insertions, 2 deletions

diff --git a/drivers/mfd/tps80031.c b/drivers/mfd/tps80031.c
index e8ea75c424c6..f0f2ce1f6840 100644
--- a/drivers/mfd/tps80031.c
+++ b/drivers/mfd/tps80031.c
@@ -105,6 +105,9 @@
 #define TPS80031_CFG_INPUT_PUPD3 0xF2
 #define TPS80031_CFG_INPUT_PUPD4 0xF3
 
+#define TPS80031_BBSPOR_CFG	0xE6
+#define TPS80031_BBSPOR_CHG_EN	0x8
+
 struct tps80031_pupd_data {
 	u8	reg;
 	u8	pullup_bit;
@@ -568,6 +571,17 @@ static void tps80031_pupd_init(struct tps80031 *tps80031,
 	}
 }
 
+static void tps80031_backup_battery_charger_control(struct tps80031 *tps80031,
+						    int enable)
+{
+	if (enable)
+		tps80031_update(tps80031->dev, SLAVE_ID1, TPS80031_BBSPOR_CFG,
+				TPS80031_BBSPOR_CHG_EN, TPS80031_BBSPOR_CHG_EN);
+	else
+		tps80031_update(tps80031->dev, SLAVE_ID1, TPS80031_BBSPOR_CFG,
+				0, TPS80031_BBSPOR_CHG_EN);
+}
+
 static void tps80031_init_ext_control(struct tps80031 *tps80031,
 			struct tps80031_platform_data *pdata) {
 	int ret;
@@ -874,8 +888,22 @@ static irqreturn_t tps80031_irq(int irq, void *data)
 	acks = (tmp[2] << 16) | (tmp[1] << 8) | tmp[0];
 
 	if (acks) {
-		ret = tps80031_writes(tps80031->dev, SLAVE_ID2,
-				      TPS80031_INT_STS_A, 3, tmp);
+		/*
+		 * Hardware behavior: hardware have the shadow register for
+		 * interrupt status register which is updated if interrupt
+		 * comes just after the interrupt status read. This shadow
+		 * register gets written to main status register and cleared
+		 * if any byte write happens in any of status register like
+		 * STS_A, STS_B or STS_C.
+		 * Hence here to clear the original interrupt status and
+		 * updating the STS register with the shadow register, it is
+		 * require to write only one byte in any of STS register.
+		 * Having multiple register write can cause the STS register
+		 * to clear without handling those interrupt and can cause
+		 * interrupt miss.
+		 */
+		ret = tps80031_write(tps80031->dev, SLAVE_ID2,
+				      TPS80031_INT_STS_A, 0);
 		if (ret < 0) {
 			dev_err(tps80031->dev, "failed to write "
 						"interrupt status\n");
@@ -1273,6 +1301,8 @@ static int __devinit tps80031_i2c_probe(struct i2c_client *client,
 
 	tps80031_debuginit(tps80031);
 
+	tps80031_backup_battery_charger_control(tps80031, 1);
+
 	if (pdata->use_power_off && !pm_power_off)
 		pm_power_off = tps80031_power_off;
 
@@ -1288,13 +1318,17 @@ fail:
 #ifdef CONFIG_PM
 static int tps80031_i2c_suspend(struct i2c_client *client, pm_message_t state)
 {
+	struct tps80031 *tps80031 = i2c_get_clientdata(client);
 	if (client->irq)
 		disable_irq(client->irq);
+	tps80031_backup_battery_charger_control(tps80031, 0);
 	return 0;
 }
 
 static int tps80031_i2c_resume(struct i2c_client *client)
 {
+	struct tps80031 *tps80031 = i2c_get_clientdata(client);
+	tps80031_backup_battery_charger_control(tps80031, 1);
 	if (client->irq)
 		enable_irq(client->irq);
 	return 0;