iio: adc: ad4695: add 2nd regmap for 16-bit registers

The AD4695 and similar chips have some multibyte registers that have
to be read/written in a single operation. So we need to add a 2nd regmap
for these registers.

These registers are removed from the 8-bit regmap allowable ranges and
AD4695_MAX_REG is dropped since it would be ambiguous now.

debugfs register access is also updated to automatically use the correct
regmap depending on the register address.

Signed-off-by: David Lechner <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jonathan Cameron <[email protected]>

Author: dlech

drivers/iio/adc/ad4695.c

@@ -34,6 +34,7 @@
 /* AD4695 registers */
 #define AD4695_REG_SPI_CONFIG_A				0x0000
 #define   AD4695_REG_SPI_CONFIG_A_SW_RST		  (BIT(7) | BIT(0))
+#define   AD4695_REG_SPI_CONFIG_A_ADDR_DIR		  BIT(5)
 #define AD4695_REG_SPI_CONFIG_B				0x0001
 #define   AD4695_REG_SPI_CONFIG_B_INST_MODE		  BIT(7)
 #define AD4695_REG_DEVICE_TYPE				0x0003
@@ -77,7 +78,6 @@
 #define AD4695_REG_GAIN_IN(n)				(0x00C0 | (2 * (n)))
 #define AD4695_REG_AS_SLOT(n)				(0x0100 | (n))
 #define   AD4695_REG_AS_SLOT_INX			  GENMASK(3, 0)
-#define AD4695_MAX_REG					0x017F
 
 /* Conversion mode commands */
 #define AD4695_CMD_EXIT_CNV_MODE	0x0A
@@ -121,6 +121,7 @@ struct ad4695_channel_config {
 struct ad4695_state {
 	struct spi_device *spi;
 	struct regmap *regmap;
+	struct regmap *regmap16;
 	struct gpio_desc *reset_gpio;
 	/* voltages channels plus temperature and timestamp */
 	struct iio_chan_spec iio_chan[AD4695_MAX_CHANNELS + 2];
@@ -150,8 +151,10 @@ static const struct regmap_range ad4695_regmap_rd_ranges[] = {
 	regmap_reg_range(AD4695_REG_SPI_CONFIG_C, AD4695_REG_SPI_STATUS),
 	regmap_reg_range(AD4695_REG_STATUS, AD4695_REG_ALERT_STATUS2),
 	regmap_reg_range(AD4695_REG_CLAMP_STATUS, AD4695_REG_CLAMP_STATUS),
-	regmap_reg_range(AD4695_REG_SETUP, AD4695_REG_TEMP_CTRL),
-	regmap_reg_range(AD4695_REG_CONFIG_IN(0), AD4695_MAX_REG),
+	regmap_reg_range(AD4695_REG_SETUP, AD4695_REG_AC_CTRL),
+	regmap_reg_range(AD4695_REG_GPIO_CTRL, AD4695_REG_TEMP_CTRL),
+	regmap_reg_range(AD4695_REG_CONFIG_IN(0), AD4695_REG_CONFIG_IN(15)),
+	regmap_reg_range(AD4695_REG_AS_SLOT(0), AD4695_REG_AS_SLOT(127)),
 };
 
 static const struct regmap_access_table ad4695_regmap_rd_table = {
@@ -164,8 +167,10 @@ static const struct regmap_range ad4695_regmap_wr_ranges[] = {
 	regmap_reg_range(AD4695_REG_SCRATCH_PAD, AD4695_REG_SCRATCH_PAD),
 	regmap_reg_range(AD4695_REG_LOOP_MODE, AD4695_REG_LOOP_MODE),
 	regmap_reg_range(AD4695_REG_SPI_CONFIG_C, AD4695_REG_SPI_STATUS),
-	regmap_reg_range(AD4695_REG_SETUP, AD4695_REG_TEMP_CTRL),
-	regmap_reg_range(AD4695_REG_CONFIG_IN(0), AD4695_MAX_REG),
+	regmap_reg_range(AD4695_REG_SETUP, AD4695_REG_AC_CTRL),
+	regmap_reg_range(AD4695_REG_GPIO_CTRL, AD4695_REG_TEMP_CTRL),
+	regmap_reg_range(AD4695_REG_CONFIG_IN(0), AD4695_REG_CONFIG_IN(15)),
+	regmap_reg_range(AD4695_REG_AS_SLOT(0), AD4695_REG_AS_SLOT(127)),
 };
 
 static const struct regmap_access_table ad4695_regmap_wr_table = {
@@ -174,15 +179,47 @@ static const struct regmap_access_table ad4695_regmap_wr_table = {
 };
 
 static const struct regmap_config ad4695_regmap_config = {
-	.name = "ad4695",
+	.name = "ad4695-8",
 	.reg_bits = 16,
 	.val_bits = 8,
-	.max_register = AD4695_MAX_REG,
+	.max_register = AD4695_REG_AS_SLOT(127),
 	.rd_table = &ad4695_regmap_rd_table,
 	.wr_table = &ad4695_regmap_wr_table,
 	.can_multi_write = true,
 };
 
+static const struct regmap_range ad4695_regmap16_rd_ranges[] = {
+	regmap_reg_range(AD4695_REG_STD_SEQ_CONFIG, AD4695_REG_STD_SEQ_CONFIG),
+	regmap_reg_range(AD4695_REG_UPPER_IN(0), AD4695_REG_GAIN_IN(15)),
+};
+
+static const struct regmap_access_table ad4695_regmap16_rd_table = {
+	.yes_ranges = ad4695_regmap16_rd_ranges,
+	.n_yes_ranges = ARRAY_SIZE(ad4695_regmap16_rd_ranges),
+};
+
+static const struct regmap_range ad4695_regmap16_wr_ranges[] = {
+	regmap_reg_range(AD4695_REG_STD_SEQ_CONFIG, AD4695_REG_STD_SEQ_CONFIG),
+	regmap_reg_range(AD4695_REG_UPPER_IN(0), AD4695_REG_GAIN_IN(15)),
+};
+
+static const struct regmap_access_table ad4695_regmap16_wr_table = {
+	.yes_ranges = ad4695_regmap16_wr_ranges,
+	.n_yes_ranges = ARRAY_SIZE(ad4695_regmap16_wr_ranges),
+};
+
+static const struct regmap_config ad4695_regmap16_config = {
+	.name = "ad4695-16",
+	.reg_bits = 16,
+	.reg_stride = 2,
+	.val_bits = 16,
+	.val_format_endian = REGMAP_ENDIAN_LITTLE,
+	.max_register = AD4695_REG_GAIN_IN(15),
+	.rd_table = &ad4695_regmap16_rd_table,
+	.wr_table = &ad4695_regmap16_wr_table,
+	.can_multi_write = true,
+};
+
 static const struct iio_chan_spec ad4695_channel_template = {
 	.type = IIO_VOLTAGE,
 	.indexed = 1,
@@ -646,13 +683,24 @@ static int ad4695_debugfs_reg_access(struct iio_dev *indio_dev,
 	struct ad4695_state *st = iio_priv(indio_dev);
 
 	iio_device_claim_direct_scoped(return -EBUSY, indio_dev) {
-		if (readval)
-			return regmap_read(st->regmap, reg, readval);
-
-		return regmap_write(st->regmap, reg, writeval);
+		if (readval) {
+			if (regmap_check_range_table(st->regmap, reg,
+						     &ad4695_regmap_rd_table))
+				return regmap_read(st->regmap, reg, readval);
+			if (regmap_check_range_table(st->regmap16, reg,
+						     &ad4695_regmap16_rd_table))
+				return regmap_read(st->regmap16, reg, readval);
+		} else {
+			if (regmap_check_range_table(st->regmap, reg,
+						     &ad4695_regmap_wr_table))
+				return regmap_write(st->regmap, reg, writeval);
+			if (regmap_check_range_table(st->regmap16, reg,
+						     &ad4695_regmap16_wr_table))
+				return regmap_write(st->regmap16, reg, writeval);
+		}
 	}
 
-	unreachable();
+	return -EINVAL;
 }
 
 static const struct iio_info ad4695_info = {
@@ -807,6 +855,11 @@ static int ad4695_probe(struct spi_device *spi)
 		return dev_err_probe(dev, PTR_ERR(st->regmap),
 				     "Failed to initialize regmap\n");
 
+	st->regmap16 = devm_regmap_init_spi(spi, &ad4695_regmap16_config);
+	if (IS_ERR(st->regmap16))
+		return dev_err_probe(dev, PTR_ERR(st->regmap16),
+				     "Failed to initialize regmap16\n");
+
 	ret = devm_regulator_bulk_get_enable(dev,
 					     ARRAY_SIZE(ad4695_power_supplies),
 					     ad4695_power_supplies);
@@ -876,9 +929,9 @@ static int ad4695_probe(struct spi_device *spi)
 		msleep(AD4695_T_WAKEUP_SW_MS);
 	}
 
-	/* Needed for debugfs since it only access registers 1 byte at a time. */
-	ret = regmap_set_bits(st->regmap, AD4695_REG_SPI_CONFIG_C,
-			      AD4695_REG_SPI_CONFIG_C_MB_STRICT);
+	/* Needed for regmap16 to be able to work correctly. */
+	ret = regmap_set_bits(st->regmap, AD4695_REG_SPI_CONFIG_A,
+			      AD4695_REG_SPI_CONFIG_A_ADDR_DIR);
 	if (ret)
 		return ret;