[PATCH 5/9] regulator: da9121: Add support for device variants via devicetree

[Adam Ward <adam.ward@diasemi.com>]

Add devicetree configuration and device variant parameters. Use the latter to
enable the check and use of parameters specific to dual buck variants.

Signed-off-by: Adam Ward <Adam.Ward.opensource@diasemi.com>
---
 drivers/regulator/da9121-regulator.c | 157 ++++++++++++++++++++++++++++++++++-
 include/linux/regulator/da9121.h     |  11 +++
 2 files changed, 167 insertions(+), 1 deletion(-)

diff --git a/drivers/regulator/da9121-regulator.c b/drivers/regulator/da9121-regulator.c
index 76932ba..5020774 100644
--- a/drivers/regulator/da9121-regulator.c
+++ b/drivers/regulator/da9121-regulator.c
@@ -1,7 +1,21 @@
 // SPDX-License-Identifier: GPL-2.0-only
-/* Copyright (C) 2020 Axis Communications AB */
+/* Copyright (C) 2020 Axis Communications AB
+ *
+ * DA9121 Single-channel dual-phase 10A buck converter
+ *
+ * Copyright (C) 2020 Dialog Semiconductor
+ *
+ * DA9130 Single-channel dual-phase 10A buck converter (Automotive)
+ * DA9217 Single-channel dual-phase  6A buck converter
+ * DA9122 Dual-channel single-phase  5A buck converter
+ * DA9131 Dual-channel single-phase  5A buck converter (Automotive)
+ * DA9220 Dual-channel single-phase  3A buck converter
+ * DA9132 Dual-channel single-phase  3A buck converter (Automotive)
+ *
+ */
 
 #include <linux/of_device.h>
+#include <linux/of_gpio.h>
 #include <linux/regulator/of_regulator.h>
 #include <linux/regulator/machine.h>
 #include <linux/regulator/driver.h>
@@ -16,11 +30,68 @@
 /* Chip data */
 struct da9121 {
 	struct device *dev;
+	struct da9121_pdata *pdata;
 	struct regmap *regmap;
 	struct regulator_dev *rdev[DA9121_IDX_MAX];
 	int variant_id;
 };
 
+/* Define ranges for different variants, enabling translation to/from
+ * registers. Maximums give scope to allow for transients.
+ */
+struct da9121_range {
+	int val_min;
+	int val_max;
+	int val_stp;
+	int reg_min;
+	int reg_max;
+};
+
+struct da9121_range da9121_10A_2phase_current = {
+	.val_min =  7000000,
+	.val_max = 20000000,
+	.val_stp =  1000000,
+	.reg_min = 1,
+	.reg_max = 14,
+};
+
+struct da9121_range da9121_6A_2phase_current = {
+	.val_min =  7000000,
+	.val_max = 12000000,
+	.val_stp =  1000000,
+	.reg_min = 1,
+	.reg_max = 6,
+};
+
+struct da9121_range da9121_5A_1phase_current = {
+	.val_min =  3500000,
+	.val_max = 10000000,
+	.val_stp =   500000,
+	.reg_min = 1,
+	.reg_max = 14,
+};
+
+struct da9121_range da9121_3A_1phase_current = {
+	.val_min = 3500000,
+	.val_max = 6000000,
+	.val_stp =  500000,
+	.reg_min = 1,
+	.reg_max = 6,
+};
+
+struct da9121_variant_info {
+	int num_bucks;
+	int num_phases;
+	struct da9121_range *current_range;
+};
+
+static const struct da9121_variant_info variant_parameters[] = {
+	{ 1, 2, &da9121_10A_2phase_current },	//DA9121_TYPE_DA9121_DA9130
+	{ 2, 1, &da9121_3A_1phase_current  },	//DA9121_TYPE_DA9220_DA9132
+	{ 2, 1, &da9121_5A_1phase_current  },	//DA9121_TYPE_DA9122_DA9131
+	{ 1, 2, &da9121_6A_2phase_current  },	//DA9121_TYPE_DA9217
+};
+
 static const struct regulator_ops da9121_buck_ops = {
 	.enable = regulator_enable_regmap,
 	.disable = regulator_disable_regmap,
@@ -163,6 +234,86 @@ struct da9121 {
 	[DA9121_TYPE_DA9217] = { &da9217_reg, NULL },
 };
 
+#ifdef CONFIG_OF
+static struct da9121_pdata *da9121_parse_regulators_dt(struct da9121 *chip)
+{
+	struct da9121_pdata *pdata;
+	struct device_node *node;
+	int num = 0;
+	int ret = 0;
+	int i, n;
+	enum gpiod_flags flags = GPIOD_OUT_HIGH | GPIOD_FLAGS_BIT_NONEXCLUSIVE;
+
+	node = of_get_child_by_name(chip->dev->of_node, "regulators");
+	if (!node) {
+		dev_err(chip->dev, "Regulators node not found\n");
+		return ERR_PTR(-ENODEV);
+	}
+
+	num = of_regulator_match(chip->dev, node, da9121_matches,
+				 ARRAY_SIZE(da9121_matches));
+	of_node_put(node);
+	if (num < 0) {
+		dev_err(chip->dev, "Failed to match regulators\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	/* interrupt assumptions require at least one buck to be configured */
+	if (num == 0) {
+		dev_err(chip->dev, "Did not match any regulators in the DT\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	pdata = devm_kzalloc(chip->dev, sizeof(*pdata), GFP_KERNEL);
+	if (!pdata)
+		return ERR_PTR(-ENOMEM);
+
+	pdata->num_buck = num;
+
+	n = 0;
+	for (i = 0; i < ARRAY_SIZE(da9121_matches); i++) {
+		if (!da9121_matches[i].init_data)
+			continue;
+
+		pdata->init_data[n] = da9121_matches[i].init_data;
+		pdata->reg_node[n] = da9121_matches[i].of_node;
+		pdata->gpiod_ren[n] = devm_gpiod_get_from_of_node(chip->dev,
+				da9121_matches[i].of_node,
+				"enable-gpios",
+				0,
+				flags,
+				"da9121-enable");
+
+		if (IS_ERR(pdata->gpiod_ren[n]))
+			pdata->gpiod_ren[n] = NULL;
+
+		if (variant_parameters[chip->variant_id].num_bucks == 2) {
+			uint32_t ripple_cancel;
+			uint32_t reg = (i ? DA9xxx_REG_BUCK_BUCK2_7
+					  : DA9121_REG_BUCK_BUCK1_7);
+			if (!of_property_read_u32(da9121_matches[i].of_node,
+				  "dlg,ripple-cancel",
+				  &ripple_cancel)) {
+				//write to BUCK_BUCKx_7 : CHx_RIPPLE_CANCEL
+				ret = regmap_update_bits(chip->regmap, reg,
+					DA9xxx_MASK_BUCK_BUCKx_7_CHx_RIPPLE_CANCEL,
+					ripple_cancel);
+				if (ret < 0)
+					dev_err(chip->dev, "Cannot update BUCK register %02x, err: %d\n", reg, ret);
+			}
+		}
+		n++;
+	}
+
+	return pdata;
+}
+#else
+static struct da9121_pdata *da9121_parse_regulators_dt(struct da9121 *chip)
+{
+	return ERR_PTR(-ENODEV);
+}
+#endif
+
 /* DA9121 chip register model */
 static const struct regmap_range da9121_1ch_readable_ranges[] = {
 	regmap_reg_range(DA9121_REG_SYS_STATUS_0, DA9121_REG_SYS_MASK_3),
@@ -445,12 +596,16 @@ static int da9121_i2c_probe(struct i2c_client *i2c,
 		goto error;
 	}
 
+	chip->pdata = i2c->dev.platform_data;
 	chip->variant_id = da9121_of_get_id(&i2c->dev);
 
 	ret = da9121_assign_chip_model(i2c, chip);
 	if (ret < 0)
 		goto error;
 
+	if (!chip->pdata)
+		chip->pdata = da9121_parse_regulators_dt(chip);
+
 	config.dev = &i2c->dev;
 	config.of_node = dev->of_node;
 	config.regmap = chip->regmap;
diff --git a/include/linux/regulator/da9121.h b/include/linux/regulator/da9121.h
index c31180d..62d9d257 100644
--- a/include/linux/regulator/da9121.h
+++ b/include/linux/regulator/da9121.h
@@ -16,10 +16,21 @@
 #ifndef __LINUX_REGULATOR_DA9121_H
 #define __LINUX_REGULATOR_DA9121_H
 
+#include <linux/regulator/machine.h>
+
+struct gpio_desc;
+
 enum {
 	DA9121_IDX_BUCK1,
 	DA9121_IDX_BUCK2,
 	DA9121_IDX_MAX
 };
 
+struct da9121_pdata {
+	int num_buck;
+	struct gpio_desc *gpiod_ren[DA9121_IDX_MAX];
+	struct device_node *reg_node[DA9121_IDX_MAX];
+	struct regulator_init_data *init_data[DA9121_IDX_MAX];
+};
+
 #endif
-- 
1.9.1