1 files changed, 61 insertions, 0 deletions

diff --git a/drivers/mfd/da9052-i2c.c b/drivers/mfd/da9052-i2c.c
index ac74a4d1daea..885e56780358 100644
--- a/drivers/mfd/da9052-i2c.c
+++ b/drivers/mfd/da9052-i2c.c
@@ -27,6 +27,66 @@
 #include <linux/of_device.h>
 #endif
 
+/* I2C safe register check */
+static inline bool i2c_safe_reg(unsigned char reg)
+{
+        switch (reg) {
+        case DA9052_STATUS_A_REG:
+        case DA9052_STATUS_B_REG:
+        case DA9052_STATUS_C_REG:
+        case DA9052_STATUS_D_REG:
+        case DA9052_ADC_RES_L_REG:
+        case DA9052_ADC_RES_H_REG:
+        case DA9052_VDD_RES_REG:
+        case DA9052_ICHG_AV_REG:
+        case DA9052_TBAT_RES_REG:
+        case DA9052_ADCIN4_RES_REG:
+        case DA9052_ADCIN5_RES_REG:
+        case DA9052_ADCIN6_RES_REG:
+        case DA9052_TJUNC_RES_REG:
+        case DA9052_TSI_X_MSB_REG:
+        case DA9052_TSI_Y_MSB_REG:
+        case DA9052_TSI_LSB_REG:
+        case DA9052_TSI_Z_MSB_REG:
+                return true;
+        default:
+                return false;
+        }
+}
+
+/*
+ * There is an issue with DA9052 and DA9053_AA/BA/BB PMIC where the PMIC
+ * gets lockup up or fails to respond following a system reset.
+ * This fix is to follow any read or write with a dummy read to a safe
+ * register.
+ */
+int da9052_i2c_fix(struct da9052 *da9052, unsigned char reg)
+{
+        int val;
+
+        switch (da9052->chip_id) {
+        case DA9052:
+        case DA9053_AA:
+        case DA9053_BA:
+        case DA9053_BB:
+                /* A dummy read to a safe register address. */
+        if (!i2c_safe_reg(reg))
+                        return regmap_read(da9052->regmap,
+                                           DA9052_PARK_REGISTER,
+                                           &val);
+                break;
+        default:
+                /*
+                 * For other chips parking of I2C register
+                 * to a safe place is not required.
+                 */
+                break;
+        }
+
+        return 0;
+}
+EXPORT_SYMBOL(da9052_i2c_fix);
+
 static int da9052_i2c_enable_multiwrite(struct da9052 *da9052)
 {
         int reg_val, ret;
@@ -83,6 +143,7 @@ static int da9052_i2c_probe(struct i2c_client *client,
 
         da9052->dev = &client->dev;
         da9052->chip_irq = client->irq;
+        da9052->fix_io = da9052_i2c_fix;
 
         i2c_set_clientdata(client, da9052);