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mfd: i2c issue fix for DA9052/53 and support for DA9053-BC

PATCH In review Ashish Jangam 2 participants 3 messages Nov 1, 2012 – Nov 2, 2012

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Multifunction devices (MFD) Dialog semiconductor drivers
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Ashish Jangam

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#0 lore raw

PATCH 1/2 mfd: i2c issue fix for DA9052/53 and support for DA9053-BC

There is an issue where the DA9052/53-AA/BA/BB PMIC either locks up or fails to respond following a system Reset. This could result in a second write in which the bus writes the current content of the write buffer to address of the last I2C access.

The failure case is where this unwanted write transfers incorrect data to a critical register.

This patch fixes this issue to by following any read or write with a dummy read to a safe register address. A safe register address is one where the contents will not affect the operation of the system.

Apart from this the patch also adds support to the DA9053-BC PMIC chip

Signed-off-by David Dajun Chen <[email protected]>
Signed-off-by Ashish Jangam <[email protected]>
---
 drivers/mfd/da9052-i2c.c          |   58 +++++++++++++++++++++++++++++++++++++
 drivers/mfd/da9052-spi.c          |    1 +
 include/linux/mfd/da9052/da9052.h |   48 ++++++++++++++++++++++++++++--
 include/linux/mfd/da9052/reg.h    |    3 ++
 4 files changed, 106 insertions(+), 4 deletions(-)
drivers/mfd/da9052-i2c.c +58 -0
index 352c58b..279e5f8 100644
@@ -27,6 +27,62 @@
 #include <linux/of_device.h>
 #endif
 
+/* safe register to park I2C operation */
+static inline bool is_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 (!is_i2c_safe_reg(reg))
+			return regmap_read(da9052->regmap, DA9052_PARK_REGISTER,
+					   &val);
+		break;
+	default:
+		/* Do nothing */
+		break;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(da9052_i2c_fix);
+
 static int da9052_i2c_enable_multiwrite(struct da9052 *da9052)
 {
 	int reg_val, ret;

@@ -51,6 +107,7 @@ static const struct i2c_device_id da9052_i2c_id[] = {
 	{"da9053-aa", DA9053_AA},
 	{"da9053-ba", DA9053_BA},
 	{"da9053-bb", DA9053_BB},
+	{"da9053-bc", DA9053_BC},
 	{}
 };
 

@@ -60,6 +117,7 @@ static const struct of_device_id dialog_dt_ids[] = {
 	{ .compatible = "dlg,da9053-aa", .data = &da9052_i2c_id[1] },
 	{ .compatible = "dlg,da9053-ab", .data = &da9052_i2c_id[2] },
 	{ .compatible = "dlg,da9053-bb", .data = &da9052_i2c_id[3] },
+	{ .compatible = "dlg,da9053-bc", .data = &da9052_i2c_id[4] },
 	{ /* sentinel */ }
 };
 #endif
drivers/mfd/da9052-spi.c +1 -0
index dbeadc5..524bd76 100644
@@ -71,6 +71,7 @@ static struct spi_device_id da9052_spi_id[] = {
 	{"da9053-aa", DA9053_AA},
 	{"da9053-ba", DA9053_BA},
 	{"da9053-bb", DA9053_BB},
+	{"da9053-bc", DA9053_BC},
 	{}
 };
include/linux/mfd/da9052/da9052.h +44 -4

88 lines not on this page · raw message

include/linux/mfd/da9052/reg.h +3 -0
index b97f730..c4dd3a8 100644
@@ -34,6 +34,9 @@
 #define DA9052_STATUS_C_REG		3
 #define DA9052_STATUS_D_REG		4
 
+/* PARK REGISTER */
+#define DA9052_PARK_REGISTER		DA9052_STATUS_D_REG
+
 /* EVENT REGISTERS */
 #define DA9052_EVENT_A_REG		5
 #define DA9052_EVENT_B_REG		6
Signature · 1 line
1.7.0.4
#1 lore raw
Quoted 5 lines · Ashish Jangam

This patch fixes this issue to by following any read or write with a dummy read to a safe register address. A safe register address is one where the contents will not affect the operation of the system.

Apart from this the patch also adds support to the DA9053-BC PMIC chip

This is two separate changes and so should be two separate patches (one is a bugfix and one isn't...).

author
#2 lore raw
Quoted 10 lines · Mark Brown
Quoted 5 lines · Ashish Jangam

This patch fixes this issue to by following any read or write with a dummy read to a safe register address. A safe register address is one where the contents will not affect the operation of the system.

Apart from this the patch also adds support to the DA9053-BC PMIC chip

This is two separate changes and so should be two separate patches (one is a bugfix and one isn't...).

I merged these two changes since I2C fix has got some dependency on DA9053-BC PMIC. But I can separate out the things, its better.