mfd: da9063: Fix revision handling to correctly select reg tables

The current implementation performs checking in the i2c_probe()
function of the variant_code but does this immediately after the
containing struct has been initialised as all zero. This means the
check for variant code will always default to using the BB tables
and will never select AD. The variant code is subsequently set
by device_init() and later used by the RTC so really it's a little
fortunate this mismatch works.

This update adds raw I2C read access functionality to read the chip
and variant/revision information (common to all revisions) so that
it can subsequently correctly choose the proper regmap tables for
real initialisation.

Signed-off-by: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

2 files changed, 167 insertions, 48 deletions

diff --git a/drivers/mfd/da9063-core.c b/drivers/mfd/da9063-core.c
index b125f90dd375..a353d52210a9 100644
--- a/drivers/mfd/da9063-core.c
+++ b/drivers/mfd/da9063-core.c
@@ -160,7 +160,6 @@ static int da9063_clear_fault_log(struct da9063 *da9063)
 
 int da9063_device_init(struct da9063 *da9063, unsigned int irq)
 {
-	int model, variant_id, variant_code;
 	int ret;
 
 	ret = da9063_clear_fault_log(da9063);
@@ -171,36 +170,6 @@ int da9063_device_init(struct da9063 *da9063, unsigned int irq)
 	da9063->irq_base = -1;
 	da9063->chip_irq = irq;
 
-	ret = regmap_read(da9063->regmap, DA9063_REG_CHIP_ID, &model);
-	if (ret < 0) {
-		dev_err(da9063->dev, "Cannot read chip model id.\n");
-		return -EIO;
-	}
-	if (model != PMIC_CHIP_ID_DA9063) {
-		dev_err(da9063->dev, "Invalid chip model id: 0x%02x\n", model);
-		return -ENODEV;
-	}
-
-	ret = regmap_read(da9063->regmap, DA9063_REG_CHIP_VARIANT, &variant_id);
-	if (ret < 0) {
-		dev_err(da9063->dev, "Cannot read chip variant id.\n");
-		return -EIO;
-	}
-
-	variant_code = variant_id >> DA9063_CHIP_VARIANT_SHIFT;
-
-	dev_info(da9063->dev,
-		 "Device detected (chip-ID: 0x%02X, var-ID: 0x%02X)\n",
-		 model, variant_id);
-
-	if (variant_code < PMIC_DA9063_BB && variant_code != PMIC_DA9063_AD) {
-		dev_err(da9063->dev,
-			"Cannot support variant code: 0x%02X\n", variant_code);
-		return -ENODEV;
-	}
-
-	da9063->variant_code = variant_code;
-
 	ret = da9063_irq_init(da9063);
 	if (ret) {
 		dev_err(da9063->dev, "Cannot initialize interrupts.\n");
diff --git a/drivers/mfd/da9063-i2c.c b/drivers/mfd/da9063-i2c.c
index 455de74c0dd2..481548948bc0 100644
--- a/drivers/mfd/da9063-i2c.c
+++ b/drivers/mfd/da9063-i2c.c
@@ -22,12 +22,124 @@
 #include <linux/of.h>
 #include <linux/regulator/of_regulator.h>
 
+/*
+ * Raw I2C access required for just accessing chip and variant info before we
+ * know which device is present. The info read from the device using this
+ * approach is then used to select the correct regmap tables.
+ */
+
+#define DA9063_REG_PAGE_SIZE		0x100
+#define DA9063_REG_PAGED_ADDR_MASK	0xFF
+
+enum da9063_page_sel_buf_fmt {
+	DA9063_PAGE_SEL_BUF_PAGE_REG = 0,
+	DA9063_PAGE_SEL_BUF_PAGE_VAL,
+	DA9063_PAGE_SEL_BUF_SIZE,
+};
+
+enum da9063_paged_read_msgs {
+	DA9063_PAGED_READ_MSG_PAGE_SEL = 0,
+	DA9063_PAGED_READ_MSG_REG_SEL,
+	DA9063_PAGED_READ_MSG_DATA,
+	DA9063_PAGED_READ_MSG_CNT,
+};
+
+static int da9063_i2c_blockreg_read(struct i2c_client *client, u16 addr,
+				    u8 *buf, int count)
+{
+	struct i2c_msg xfer[DA9063_PAGED_READ_MSG_CNT];
+	u8 page_sel_buf[DA9063_PAGE_SEL_BUF_SIZE];
+	u8 page_num, paged_addr;
+	int ret;
+
+	/* Determine page info based on register address */
+	page_num = (addr / DA9063_REG_PAGE_SIZE);
+	if (page_num > 1) {
+		dev_err(&client->dev, "Invalid register address provided\n");
+		return -EINVAL;
+	}
+
+	paged_addr = (addr % DA9063_REG_PAGE_SIZE) & DA9063_REG_PAGED_ADDR_MASK;
+	page_sel_buf[DA9063_PAGE_SEL_BUF_PAGE_REG] = DA9063_REG_PAGE_CON;
+	page_sel_buf[DA9063_PAGE_SEL_BUF_PAGE_VAL] =
+		(page_num << DA9063_I2C_PAGE_SEL_SHIFT) & DA9063_REG_PAGE_MASK;
+
+	/* Write reg address, page selection */
+	xfer[DA9063_PAGED_READ_MSG_PAGE_SEL].addr = client->addr;
+	xfer[DA9063_PAGED_READ_MSG_PAGE_SEL].flags = 0;
+	xfer[DA9063_PAGED_READ_MSG_PAGE_SEL].len = DA9063_PAGE_SEL_BUF_SIZE;
+	xfer[DA9063_PAGED_READ_MSG_PAGE_SEL].buf = page_sel_buf;
+
+	/* Select register address */
+	xfer[DA9063_PAGED_READ_MSG_REG_SEL].addr = client->addr;
+	xfer[DA9063_PAGED_READ_MSG_REG_SEL].flags = 0;
+	xfer[DA9063_PAGED_READ_MSG_REG_SEL].len = sizeof(paged_addr);
+	xfer[DA9063_PAGED_READ_MSG_REG_SEL].buf = &paged_addr;
+
+	/* Read data */
+	xfer[DA9063_PAGED_READ_MSG_DATA].addr = client->addr;
+	xfer[DA9063_PAGED_READ_MSG_DATA].flags = I2C_M_RD;
+	xfer[DA9063_PAGED_READ_MSG_DATA].len = count;
+	xfer[DA9063_PAGED_READ_MSG_DATA].buf = buf;
+
+	ret = i2c_transfer(client->adapter, xfer, DA9063_PAGED_READ_MSG_CNT);
+	if (ret < 0) {
+		dev_err(&client->dev, "Paged block read failed: %d\n", ret);
+		return ret;
+	}
+
+	if (ret != DA9063_PAGED_READ_MSG_CNT) {
+		dev_err(&client->dev, "Paged block read failed to complete\n");
+		return -EIO;
+	}
+
+	return 0;
+}
+
+enum {
+	DA9063_DEV_ID_REG = 0,
+	DA9063_VAR_ID_REG,
+	DA9063_CHIP_ID_REGS,
+};
+
+static int da9063_get_device_type(struct i2c_client *i2c, struct da9063 *da9063)
+{
+	u8 buf[DA9063_CHIP_ID_REGS];
+	int ret;
+
+	ret = da9063_i2c_blockreg_read(i2c, DA9063_REG_DEVICE_ID, buf,
+				       DA9063_CHIP_ID_REGS);
+	if (ret)
+		return ret;
+
+	if (buf[DA9063_DEV_ID_REG] != PMIC_CHIP_ID_DA9063) {
+		dev_err(da9063->dev,
+			"Invalid chip device ID: 0x%02x\n",
+			buf[DA9063_DEV_ID_REG]);
+		return -ENODEV;
+	}
+
+	dev_info(da9063->dev,
+		 "Device detected (chip-ID: 0x%02X, var-ID: 0x%02X)\n",
+		 buf[DA9063_DEV_ID_REG], buf[DA9063_VAR_ID_REG]);
+
+	da9063->variant_code =
+		(buf[DA9063_VAR_ID_REG] & DA9063_VARIANT_ID_MRC_MASK)
+		>> DA9063_VARIANT_ID_MRC_SHIFT;
+
+	return 0;
+}
+
+/*
+ * Variant specific regmap configs
+ */
+
 static const struct regmap_range da9063_ad_readable_ranges[] = {
 	regmap_reg_range(DA9063_REG_PAGE_CON, DA9063_AD_REG_SECOND_D),
 	regmap_reg_range(DA9063_REG_SEQ, DA9063_REG_ID_32_31),
 	regmap_reg_range(DA9063_REG_SEQ_A, DA9063_REG_AUTO3_LOW),
 	regmap_reg_range(DA9063_REG_T_OFFSET, DA9063_AD_REG_GP_ID_19),
-	regmap_reg_range(DA9063_REG_CHIP_ID, DA9063_REG_CHIP_VARIANT),
+	regmap_reg_range(DA9063_REG_DEVICE_ID, DA9063_REG_VARIANT_ID),
 };
 
 static const struct regmap_range da9063_ad_writeable_ranges[] = {
@@ -72,7 +184,7 @@ static const struct regmap_range da9063_bb_readable_ranges[] = {
 	regmap_reg_range(DA9063_REG_SEQ, DA9063_REG_ID_32_31),
 	regmap_reg_range(DA9063_REG_SEQ_A, DA9063_REG_AUTO3_LOW),
 	regmap_reg_range(DA9063_REG_T_OFFSET, DA9063_BB_REG_GP_ID_19),
-	regmap_reg_range(DA9063_REG_CHIP_ID, DA9063_REG_CHIP_VARIANT),
+	regmap_reg_range(DA9063_REG_DEVICE_ID, DA9063_REG_VARIANT_ID),
 };
 
 static const struct regmap_range da9063_bb_writeable_ranges[] = {
@@ -117,7 +229,7 @@ static const struct regmap_range da9063l_bb_readable_ranges[] = {
 	regmap_reg_range(DA9063_REG_SEQ, DA9063_REG_ID_32_31),
 	regmap_reg_range(DA9063_REG_SEQ_A, DA9063_REG_AUTO3_LOW),
 	regmap_reg_range(DA9063_REG_T_OFFSET, DA9063_BB_REG_GP_ID_19),
-	regmap_reg_range(DA9063_REG_CHIP_ID, DA9063_REG_CHIP_VARIANT),
+	regmap_reg_range(DA9063_REG_DEVICE_ID, DA9063_REG_VARIANT_ID),
 };
 
 static const struct regmap_range da9063l_bb_writeable_ranges[] = {
@@ -159,7 +271,7 @@ static const struct regmap_access_table da9063l_bb_volatile_table = {
 static const struct regmap_range_cfg da9063_range_cfg[] = {
 	{
 		.range_min = DA9063_REG_PAGE_CON,
-		.range_max = DA9063_REG_CHIP_VARIANT,
+		.range_max = DA9063_REG_CONFIG_ID,
 		.selector_reg = DA9063_REG_PAGE_CON,
 		.selector_mask = 1 << DA9063_I2C_PAGE_SEL_SHIFT,
 		.selector_shift = DA9063_I2C_PAGE_SEL_SHIFT,
@@ -173,7 +285,7 @@ static struct regmap_config da9063_regmap_config = {
 	.val_bits = 8,
 	.ranges = da9063_range_cfg,
 	.num_ranges = ARRAY_SIZE(da9063_range_cfg),
-	.max_register = DA9063_REG_CHIP_VARIANT,
+	.max_register = DA9063_REG_CONFIG_ID,
 
 	.cache_type = REGCACHE_RBTREE,
 };
@@ -199,18 +311,56 @@ static int da9063_i2c_probe(struct i2c_client *i2c,
 	da9063->chip_irq = i2c->irq;
 	da9063->type = id->driver_data;
 
-	if (da9063->variant_code == PMIC_DA9063_AD) {
-		da9063_regmap_config.rd_table = &da9063_ad_readable_table;
-		da9063_regmap_config.wr_table = &da9063_ad_writeable_table;
-		da9063_regmap_config.volatile_table = &da9063_ad_volatile_table;
-	} else if (da9063->type == PMIC_TYPE_DA9063L) {
-		da9063_regmap_config.rd_table = &da9063l_bb_readable_table;
-		da9063_regmap_config.wr_table = &da9063l_bb_writeable_table;
-		da9063_regmap_config.volatile_table = &da9063l_bb_volatile_table;
-	} else {
-		da9063_regmap_config.rd_table = &da9063_bb_readable_table;
-		da9063_regmap_config.wr_table = &da9063_bb_writeable_table;
-		da9063_regmap_config.volatile_table = &da9063_bb_volatile_table;
+	ret = da9063_get_device_type(i2c, da9063);
+	if (ret)
+		return ret;
+
+	switch (da9063->type) {
+	case PMIC_TYPE_DA9063:
+		switch (da9063->variant_code) {
+		case PMIC_DA9063_AD:
+			da9063_regmap_config.rd_table =
+				&da9063_ad_readable_table;
+			da9063_regmap_config.wr_table =
+				&da9063_ad_writeable_table;
+			da9063_regmap_config.volatile_table =
+				&da9063_ad_volatile_table;
+			break;
+		case PMIC_DA9063_BB:
+		case PMIC_DA9063_CA:
+			da9063_regmap_config.rd_table =
+				&da9063_bb_readable_table;
+			da9063_regmap_config.wr_table =
+				&da9063_bb_writeable_table;
+			da9063_regmap_config.volatile_table =
+				&da9063_bb_volatile_table;
+			break;
+		default:
+			dev_err(da9063->dev,
+				"Chip variant not supported for DA9063\n");
+			return -ENODEV;
+		}
+		break;
+	case PMIC_TYPE_DA9063L:
+		switch (da9063->variant_code) {
+		case PMIC_DA9063_BB:
+		case PMIC_DA9063_CA:
+			da9063_regmap_config.rd_table =
+				&da9063l_bb_readable_table;
+			da9063_regmap_config.wr_table =
+				&da9063l_bb_writeable_table;
+			da9063_regmap_config.volatile_table =
+				&da9063l_bb_volatile_table;
+			break;
+		default:
+			dev_err(da9063->dev,
+				"Chip variant not supported for DA9063L\n");
+			return -ENODEV;
+		}
+		break;
+	default:
+		dev_err(da9063->dev, "Chip type not supported\n");
+		return -ENODEV;
 	}
 
 	da9063->regmap = devm_regmap_init_i2c(i2c, &da9063_regmap_config);