[PATCH v2 6/8] regulator: arizona-micbias: Add regulator driver for Arizona micbiases

[Charles Keepax <ckeepax@opensource.wolfsonmicro.com>]

Add a driver for controlling the micbias regulators on the Arizona class
audio CODECs. This will replace earlier fixed support that initialised
the micbias's with fixed settings from platform data, although that
platform data can still be used to configure the constraints on this new
regulator.

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
---

Changes since v1:
 - Use active_discharge rather than pull_down as that is what the
   regulator actually does.
 - Pass the micbias device rather than the arizona device to
   of_get_regulator_init_data to avoid leaking init_data
 - Update the pdata to use an actual regulator_init_data
 - Tidy up the code to make it a little easier to follow

 drivers/regulator/Makefile          |   2 +-
 drivers/regulator/arizona-micbias.c | 228 ++++++++++++++++++++++++++++++++++++
 include/linux/mfd/arizona/pdata.h   |   6 +-
 3 files changed, 231 insertions(+), 5 deletions(-)
 create mode 100644 drivers/regulator/arizona-micbias.c

diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index ef7725e..b670e87 100644
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -19,7 +19,7 @@ obj-$(CONFIG_REGULATOR_ACT8865) += act8865-regulator.o
 obj-$(CONFIG_REGULATOR_ACT8945A) += act8945a-regulator.o
 obj-$(CONFIG_REGULATOR_AD5398) += ad5398.o
 obj-$(CONFIG_REGULATOR_ANATOP) += anatop-regulator.o
-obj-$(CONFIG_REGULATOR_ARIZONA) += arizona-micsupp.o arizona-ldo1.o
+obj-$(CONFIG_REGULATOR_ARIZONA) += arizona-micsupp.o arizona-ldo1.o arizona-micbias.o
 obj-$(CONFIG_REGULATOR_AS3711) += as3711-regulator.o
 obj-$(CONFIG_REGULATOR_AS3722) += as3722-regulator.o
 obj-$(CONFIG_REGULATOR_AXP20X) += axp20x-regulator.o
diff --git a/drivers/regulator/arizona-micbias.c b/drivers/regulator/arizona-micbias.c
new file mode 100644
index 0000000..622e659
--- /dev/null
+++ b/drivers/regulator/arizona-micbias.c
@@ -0,0 +1,228 @@
+/*
+ * arizona-micbias.c  --  Microphone bias supplies for Arizona devices
+ *
+ * Copyright 2017 Cirrus Logic Inc.
+ *
+ * Author: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
+ *
+ *  This program is free software; you can redistribute  it and/or modify it
+ *  under  the terms of  the GNU General  Public License as published by the
+ *  Free Software Foundation;  either version 2 of the  License, or (at your
+ *  option) any later version.
+ */
+
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/machine.h>
+#include <linux/regulator/of_regulator.h>
+#include <linux/slab.h>
+
+#include <linux/mfd/arizona/core.h>
+#include <linux/mfd/arizona/pdata.h>
+#include <linux/mfd/arizona/registers.h>
+
+#define ARIZONA_MICBIAS_MAX_SELECTOR 0xD
+
+struct arizona_micbias_priv {
+	int id;
+	struct arizona *arizona;
+
+	struct device_node *np;
+	struct regulator_desc desc;
+	struct regulator_consumer_supply supply;
+	struct regulator_init_data *init_data;
+
+	struct regulator_dev *regulator;
+};
+
+static const struct regulator_ops arizona_micbias_ops = {
+	.enable = regulator_enable_regmap,
+	.disable = regulator_disable_regmap,
+	.is_enabled = regulator_is_enabled_regmap,
+	.list_voltage = regulator_list_voltage_linear,
+	.map_voltage = regulator_map_voltage_linear,
+	.get_voltage_sel = regulator_get_voltage_sel_regmap,
+	.set_voltage_sel = regulator_set_voltage_sel_regmap,
+	.get_bypass = regulator_get_bypass_regmap,
+	.set_bypass = regulator_set_bypass_regmap,
+	.set_soft_start = regulator_set_soft_start_regmap,
+	.set_active_discharge = regulator_set_active_discharge_regmap,
+};
+
+static const struct regulator_desc arizona_micbias_desc_tmpl = {
+	.supply_name = "MICVDD",
+	.type = REGULATOR_VOLTAGE,
+	.ops = &arizona_micbias_ops,
+
+	.min_uV = 1500000,
+	.uV_step = 100000,
+	.n_voltages = ARIZONA_MICBIAS_MAX_SELECTOR + 1,
+
+	.vsel_reg = ARIZONA_MIC_BIAS_CTRL_1,
+	.vsel_mask = ARIZONA_MICB1_LVL_MASK,
+	.enable_reg = ARIZONA_MIC_BIAS_CTRL_1,
+	.enable_mask = ARIZONA_MICB1_ENA,
+	.bypass_reg = ARIZONA_MIC_BIAS_CTRL_1,
+	.bypass_mask = ARIZONA_MICB1_BYPASS,
+	.soft_start_reg = ARIZONA_MIC_BIAS_CTRL_1,
+	.soft_start_mask = ARIZONA_MICB1_RATE,
+	.active_discharge_reg = ARIZONA_MIC_BIAS_CTRL_1,
+	.active_discharge_mask = ARIZONA_MICB1_DISCH,
+	.active_discharge_on = ARIZONA_MICB1_DISCH,
+
+	.owner = THIS_MODULE,
+};
+
+static const struct regulator_init_data arizona_micbias_tmpl = {
+	.constraints = {
+		.valid_ops_mask = REGULATOR_CHANGE_STATUS |
+				  REGULATOR_CHANGE_VOLTAGE |
+				  REGULATOR_CHANGE_BYPASS,
+		.min_uV = 1500000,
+		.max_uV = 2800000,
+	},
+};
+
+static int arizona_micbias_of_get_pdata(struct device *dev,
+					struct device_node *np,
+					struct arizona_micbias_priv *micbias)
+{
+	struct arizona *arizona = micbias->arizona;
+	struct arizona_micbias *pdata = &arizona->pdata.micbias[micbias->id];
+
+	micbias->np = of_get_child_by_name(np, micbias->desc.name);
+	if (micbias->np) {
+		micbias->init_data = of_get_regulator_init_data(dev,
+								micbias->np,
+								&micbias->desc);
+
+		pdata->ext_cap = of_property_read_bool(micbias->np,
+						       "wlf,ext-cap");
+	}
+
+	return 0;
+}
+
+static int arizona_micbias_init_pdata(struct device *dev,
+				      struct arizona_micbias_priv *micbias)
+{
+	struct arizona *arizona = micbias->arizona;
+	struct arizona_micbias *pdata = &arizona->pdata.micbias[micbias->id];
+	int ret;
+
+	if (pdata->init_data)
+		return 0;
+
+	if (IS_ENABLED(CONFIG_OF)) {
+		struct device_node *np = arizona->dev->of_node;
+
+		ret = arizona_micbias_of_get_pdata(dev, np, micbias);
+		if (ret < 0) {
+			dev_err(dev, "Failed to parse DT: %d\n", ret);
+			return ret;
+		}
+	}
+
+	if (!micbias->init_data) {
+		micbias->init_data = devm_kmemdup(dev,
+						  &arizona_micbias_tmpl,
+						  sizeof(arizona_micbias_tmpl),
+						  GFP_KERNEL);
+		if (!micbias->init_data)
+			return -ENOMEM;
+	}
+
+	micbias->supply.supply = micbias->desc.name;
+	micbias->supply.dev_name = dev_name(arizona->dev);
+
+	micbias->init_data->consumer_supplies = &micbias->supply;
+	micbias->init_data->num_consumer_supplies = 1;
+
+	pdata->init_data = micbias->init_data;
+
+	return 0;
+}
+
+static int arizona_micbias_probe(struct platform_device *pdev)
+{
+	struct arizona *arizona = dev_get_drvdata(pdev->dev.parent);
+	int id = pdev->id;
+	struct arizona_micbias *pdata = &arizona->pdata.micbias[id];
+	struct arizona_micbias_priv *micbias;
+	struct regulator_config config = { };
+	unsigned int val;
+	int ret;
+
+	micbias = devm_kzalloc(&pdev->dev, sizeof(*micbias), GFP_KERNEL);
+	if (micbias == NULL)
+		return -ENOMEM;
+
+	micbias->id = id;
+	micbias->arizona = arizona;
+
+	micbias->desc = arizona_micbias_desc_tmpl;
+	micbias->desc.name = devm_kasprintf(&pdev->dev, GFP_KERNEL,
+					    "MICBIAS%d", id + 1);
+	micbias->desc.vsel_reg += id;
+	micbias->desc.enable_reg += id;
+	micbias->desc.bypass_reg += id;
+	micbias->desc.soft_start_reg += id;
+	micbias->desc.pull_down_reg += id;
+
+	ret = arizona_micbias_init_pdata(&pdev->dev, micbias);
+	if (ret)
+		return ret;
+
+	if (pdata->ext_cap)
+		val = ARIZONA_MICB1_EXT_CAP;
+	else
+		val = 0;
+
+	/*
+	 * The core expects the regulator to have bypass disabled by default
+	 * so clear it, whilst we set the external cap.
+	 */
+	regmap_update_bits(arizona->regmap, ARIZONA_MIC_BIAS_CTRL_1 + id,
+			   ARIZONA_MICB1_EXT_CAP | ARIZONA_MICB1_BYPASS, val);
+
+	config.dev = arizona->dev;
+	config.regmap = arizona->regmap;
+	config.of_node = micbias->np;
+	config.init_data = pdata->init_data;
+	config.driver_data = micbias;
+
+	micbias->regulator = devm_regulator_register(&pdev->dev,
+						     &micbias->desc,
+						     &config);
+
+	of_node_put(config.of_node);
+
+	if (IS_ERR(micbias->regulator)) {
+		ret = PTR_ERR(micbias->regulator);
+		dev_err(arizona->dev, "Failed to register %s supply: %d\n",
+			micbias->desc.name, ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static struct platform_driver arizona_micbias_driver = {
+	.probe = arizona_micbias_probe,
+	.driver		= {
+		.name	= "arizona-micbias",
+	},
+};
+
+module_platform_driver(arizona_micbias_driver);
+
+/* Module information */
+MODULE_AUTHOR("Charles Keepax <ckeepax@opensource.wolfsonmicro.com>");
+MODULE_DESCRIPTION("Arizona microphone bias supply driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:arizona-micbias");
diff --git a/include/linux/mfd/arizona/pdata.h b/include/linux/mfd/arizona/pdata.h
index 64faeef..89a3512 100644
--- a/include/linux/mfd/arizona/pdata.h
+++ b/include/linux/mfd/arizona/pdata.h
@@ -56,11 +56,9 @@
 struct regulator_init_data;
 
 struct arizona_micbias {
-	int mV;                    /** Regulated voltage */
+	/* Regulator configuration */
+	const struct regulator_init_data *init_data;
 	unsigned int ext_cap:1;    /** External capacitor fitted */
-	unsigned int discharge:1;  /** Actively discharge */
-	unsigned int soft_start:1; /** Disable aggressive startup ramp rate */
-	unsigned int bypass:1;     /** Use bypass mode */
 };
 
 struct arizona_micd_config {
-- 
2.1.4