[PATCH 1/2] AB3100 regulator support v3

[PATCH 1/2] AB3100 regulator support v3

[Linus Walleij]

This adds support for the regulators found in the AB3100
Mixed-Signal IC.

It further also defines platform data for the ST-Ericsson
U300 platform and extends the AB3100 MFD driver so that
platform/board data with regulation constraints and an init
function can be passed down all the way from the board to
the regulators.

Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Liam Girdwood <lrg@slimlogic.co.uk>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Cc: Russell King <linux@arm.linux.org.uk>
---
ChangeLog v2->v3

- Fixed an embarrasing bug with comparing the best index
  for a good voltage with the iterator instead of the
  actual best index in the errorpath.

- Assign the external regulator a fixed voltage instead
  of trying to enable callbacks to the platform code.

- Pass in initdata in an u8 array with strict ordering
  which the platform code have to respect. This avoids
  the beginings of a hairy sequencing code.

- Loose the sleep mode "regulators" implement the
  set_suspend_voltage() operation instead.

- Make sure init_data to be as complete as possible before
  registering a regulator since the framework may call
  out to accessor functions during registration.
---
 drivers/mfd/ab3100-core.c  |    4 +
 drivers/regulator/Kconfig  |    9 +
 drivers/regulator/Makefile |    1 +
 drivers/regulator/ab3100.c |  694 ++++++++++++++++++++++++++++++++++++++++++++
 include/linux/mfd/ab3100.h |   28 ++
 5 files changed, 736 insertions(+), 0 deletions(-)
 create mode 100644 drivers/regulator/ab3100.c

diff --git a/drivers/mfd/ab3100-core.c b/drivers/mfd/ab3100-core.c
index 1d8ac1a..9411860 100644
--- a/drivers/mfd/ab3100-core.c
+++ b/drivers/mfd/ab3100-core.c
@@ -838,6 +838,8 @@ static int __init ab3100_probe(struct i2c_client *client,
 			const struct i2c_device_id *id)
 {
 	struct ab3100 *ab3100;
+	struct ab3100_platform_data *ab3100_plf_data =
+		client->dev.platform_data;
 	int err;
 	int i;
 
@@ -921,6 +923,8 @@ static int __init ab3100_probe(struct i2c_client *client,
 	for (i = 0; i < ARRAY_SIZE(ab3100_platform_devs); i++) {
 		ab3100_platform_devs[i]->dev.parent =
 			&client->dev;
+		ab3100_platform_devs[i]->dev.platform_data =
+			ab3100_plf_data;
 		platform_set_drvdata(ab3100_platform_devs[i], ab3100);
 	}
 
diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index 7e1b2df..33b4eba 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -154,5 +154,14 @@ config REGULATOR_TPS6507X
 	  three step-down converters and two general-purpose LDO voltage regulators.
 	  It supports TI's software based Class-2 SmartReflex implementation.
 
+config REGULATOR_AB3100
+	tristate "ST-Ericsson AB3100 Regulator functions"
+	depends on AB3100_CORE
+	default y if AB3100_CORE
+	help
+	 These regulators correspond to functionality in the
+	 AB3100 analog baseband dealing with power regulators
+	 for the system.
+
 endif
 
diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index e42745e..d1db7db 100644
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -24,5 +24,6 @@ obj-$(CONFIG_REGULATOR_MC13783) += mc13783.o
 
 obj-$(CONFIG_REGULATOR_TPS65023) += tps65023-regulator.o
 obj-$(CONFIG_REGULATOR_TPS6507X) += tps6507x-regulator.o
+obj-$(CONFIG_REGULATOR_AB3100) += ab3100.o
 
 ccflags-$(CONFIG_REGULATOR_DEBUG) += -DDEBUG
diff --git a/drivers/regulator/ab3100.c b/drivers/regulator/ab3100.c
new file mode 100644
index 0000000..156979d
--- /dev/null
+++ b/drivers/regulator/ab3100.c
@@ -0,0 +1,694 @@
+/*
+ * drivers/regulator/ab3100.c
+ *
+ * Copyright (C) 2008-2009 ST-Ericsson AB
+ * License terms: GNU General Public License (GPL) version 2
+ * Low-level control of the AB3100 IC Low Dropout (LDO)
+ * regulators, external regulator and buck converter
+ * Author: Mattias Wallin <mattias.wallin@stericsson.com>
+ * Author: Linus Walleij <linus.walleij@stericsson.com>
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/driver.h>
+#include <linux/mfd/ab3100.h>
+
+/* LDO registers and some handy masking definitions for AB3100 */
+#define AB3100_LDO_A		0x40
+#define AB3100_LDO_C		0x41
+#define AB3100_LDO_D		0x42
+#define AB3100_LDO_E		0x43
+#define AB3100_LDO_E_SLEEP	0x44
+#define AB3100_LDO_F		0x45
+#define AB3100_LDO_G		0x46
+#define AB3100_LDO_H		0x47
+#define AB3100_LDO_H_SLEEP_MODE	0
+#define AB3100_LDO_H_SLEEP_EN	2
+#define AB3100_LDO_ON		4
+#define AB3100_LDO_H_VSEL_AC	5
+#define AB3100_LDO_K		0x48
+#define AB3100_LDO_EXT		0x49
+#define AB3100_BUCK		0x4A
+#define AB3100_BUCK_SLEEP	0x4B
+#define AB3100_REG_ON_MASK	0x10
+
+/**
+ * struct ab3100_regulator
+ * A struct passed around the individual regulator functions
+ * @platform_device: platform device holding this regulator
+ * @ab3100: handle to the AB3100 parent chip
+ * @plfdata: AB3100 platform data passed in at probe time
+ * @regreg: regulator register number in the AB3100
+ * @fixed_voltage: a fixed voltage for this regulator, if this
+ *          0 the voltages array is used instead.
+ * @typ_voltages: an array of available typical voltages for
+ *          this regulator
+ * @voltages_len: length of the array of available voltages
+ */
+struct ab3100_regulator {
+	struct regulator_dev *rdev;
+	struct ab3100 *ab3100;
+	struct ab3100_platform_data *plfdata;
+	u8 regreg;
+	int fixed_voltage;
+	int const *typ_voltages;
+	u8 voltages_len;
+};
+
+/* The order in which registers are initialized */
+static const u8 ab3100_reg_init_order[AB3100_NUM_REGULATORS+2] = {
+	AB3100_LDO_A,
+	AB3100_LDO_C,
+	AB3100_LDO_E,
+	AB3100_LDO_E_SLEEP,
+	AB3100_LDO_F,
+	AB3100_LDO_G,
+	AB3100_LDO_H,
+	AB3100_LDO_K,
+	AB3100_LDO_EXT,
+	AB3100_BUCK,
+	AB3100_BUCK_SLEEP,
+	AB3100_LDO_D,
+};
+
+/* Preset (hardware defined) voltages for these regulators */
+#define LDO_A_VOLTAGE 2750000
+#define LDO_C_VOLTAGE 2650000
+#define LDO_D_VOLTAGE 2650000
+
+static const int const ldo_e_buck_typ_voltages[] = {
+	1800000,
+	1400000,
+	1300000,
+	1200000,
+	1100000,
+	1050000,
+	900000,
+};
+
+static const int const ldo_f_typ_voltages[] = {
+	1800000,
+	1400000,
+	1300000,
+	1200000,
+	1100000,
+	1050000,
+	2500000,
+	2650000,
+};
+
+static const int const ldo_g_typ_voltages[] = {
+	2850000,
+	2750000,
+	1800000,
+	1500000,
+};
+
+static const int const ldo_h_typ_voltages[] = {
+	2750000,
+	1800000,
+	1500000,
+	1200000,
+};
+
+static const int const ldo_k_typ_voltages[] = {
+	2750000,
+	1800000,
+};
+
+
+/* The regulator devices */
+static struct ab3100_regulator
+ab3100_regulators[AB3100_NUM_REGULATORS] = {
+	{
+		.regreg = AB3100_LDO_A,
+		.fixed_voltage = LDO_A_VOLTAGE,
+	},
+	{
+		.regreg = AB3100_LDO_C,
+		.fixed_voltage = LDO_C_VOLTAGE,
+	},
+	{
+		.regreg = AB3100_LDO_D,
+		.fixed_voltage = LDO_D_VOLTAGE,
+	},
+	{
+		.regreg = AB3100_LDO_E,
+		.typ_voltages = ldo_e_buck_typ_voltages,
+		.voltages_len = ARRAY_SIZE(ldo_e_buck_typ_voltages),
+	},
+	{
+		.regreg = AB3100_LDO_F,
+		.typ_voltages = ldo_f_typ_voltages,
+		.voltages_len = ARRAY_SIZE(ldo_f_typ_voltages),
+	},
+	{
+		.regreg = AB3100_LDO_G,
+		.typ_voltages = ldo_g_typ_voltages,
+		.voltages_len = ARRAY_SIZE(ldo_g_typ_voltages),
+	},
+	{
+		.regreg = AB3100_LDO_H,
+		.typ_voltages = ldo_h_typ_voltages,
+		.voltages_len = ARRAY_SIZE(ldo_h_typ_voltages),
+	},
+	{
+		.regreg = AB3100_LDO_K,
+		.typ_voltages = ldo_k_typ_voltages,
+		.voltages_len = ARRAY_SIZE(ldo_k_typ_voltages),
+	},
+	{
+		.regreg = AB3100_LDO_EXT,
+		/* No voltages for the external regulator */
+	},
+	{
+		.regreg = AB3100_BUCK,
+		.typ_voltages = ldo_e_buck_typ_voltages,
+		.voltages_len = ARRAY_SIZE(ldo_e_buck_typ_voltages),
+	},
+};
+
+/*
+ * General functions for enable, disable and is_enabled used for
+ * LDO: A,C,E,F,G,H,K,EXT and BUCK
+ */
+static int ab3100_enable_regulator(struct regulator_dev *reg)
+{
+	struct ab3100_regulator *abreg = reg->reg_data;
+	int err;
+	u8 regval;
+
+	err = ab3100_get_register_interruptible(abreg->ab3100, abreg->regreg,
+						&regval);
+	if (err) {
+		dev_warn(&reg->dev, "failed to get regid %d value\n",
+			 abreg->regreg);
+		return err;
+	}
+
+	/* The regulator is already on, no reason to go further */
+	if (regval & AB3100_REG_ON_MASK)
+		return 0;
+
+	regval |= AB3100_REG_ON_MASK;
+
+	err = ab3100_set_register_interruptible(abreg->ab3100, abreg->regreg,
+						regval);
+	if (err) {
+		dev_warn(&reg->dev, "failed to set regid %d value\n",
+			 abreg->regreg);
+		return err;
+	}
+
+	/* Per-regulator power on delay from spec */
+	switch (abreg->regreg) {
+	case AB3100_LDO_A: /* Fallthrough */
+	case AB3100_LDO_C: /* Fallthrough */
+	case AB3100_LDO_D: /* Fallthrough */
+	case AB3100_LDO_E: /* Fallthrough */
+	case AB3100_LDO_H: /* Fallthrough */
+	case AB3100_LDO_K:
+		udelay(200);
+		break;
+	case AB3100_LDO_F:
+		udelay(600);
+		break;
+	case AB3100_LDO_G:
+		udelay(400);
+		break;
+	case AB3100_BUCK:
+		mdelay(1);
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+static int ab3100_disable_regulator(struct regulator_dev *reg)
+{
+	struct ab3100_regulator *abreg = reg->reg_data;
+	int err;
+	u8 regval;
+
+	/*
+	 * LDO D is a special regulator. When it is disabled, the entire
+	 * system is shut down. So this is handled specially.
+	 */
+	if (abreg->regreg == AB3100_LDO_D) {
+		int i;
+
+		dev_info(&reg->dev, "disabling LDO D - shut down system\n");
+		/*
+		 * Set regulators to default values, ignore any errors,
+		 * we're going DOWN
+		 */
+		for (i = 0; i < ARRAY_SIZE(ab3100_reg_init_order); i++) {
+			(void) ab3100_set_register_interruptible(abreg->ab3100,
+					ab3100_reg_init_order[i],
+					abreg->plfdata->reg_initvals[i]);
+		}
+
+		/* Setting LDO D to 0x00 cuts the power to the SoC */
+		return ab3100_set_register_interruptible(abreg->ab3100,
+							 AB3100_LDO_D, 0x00U);
+
+	}
+
+	/*
+	 * All other regulators are handled here
+	 */
+	err = ab3100_get_register_interruptible(abreg->ab3100, abreg->regreg,
+						&regval);
+	if (err) {
+		dev_err(&reg->dev, "unable to get register 0x%x\n",
+			abreg->regreg);
+		return err;
+	}
+	regval &= ~AB3100_REG_ON_MASK;
+	return ab3100_set_register_interruptible(abreg->ab3100, abreg->regreg,
+						 regval);
+}
+
+static int ab3100_is_enabled_regulator(struct regulator_dev *reg)
+{
+	struct ab3100_regulator *abreg = reg->reg_data;
+	u8 regval;
+	int err;
+
+	err = ab3100_get_register_interruptible(abreg->ab3100, abreg->regreg,
+						&regval);
+	if (err) {
+		dev_err(&reg->dev, "unable to get register 0x%x\n",
+			abreg->regreg);
+		return err;
+	}
+
+	return regval & AB3100_REG_ON_MASK;
+}
+
+static int ab3100_list_voltage_regulator(struct regulator_dev *reg,
+					 unsigned selector)
+{
+	struct ab3100_regulator *abreg = reg->reg_data;
+
+	if (selector > abreg->voltages_len)
+		return -EINVAL;
+	return abreg->typ_voltages[selector];
+}
+
+static int ab3100_get_voltage_regulator(struct regulator_dev *reg)
+{
+	struct ab3100_regulator *abreg = reg->reg_data;
+	u8 regval;
+	int err;
+
+	/* Return the voltage for fixed regulators immediately */
+	if (abreg->fixed_voltage)
+		return abreg->fixed_voltage;
+
+	/*
+	 * For variable types, read out setting and index into
+	 * supplied voltage list.
+	 */
+	err = ab3100_get_register_interruptible(abreg->ab3100,
+						abreg->regreg, &regval);
+	if (err) {
+		dev_warn(&reg->dev,
+			 "failed to get regulator value in register %02x\n",
+			 abreg->regreg);
+		return err;
+	}
+
+	/* The 3 highest bits index voltages */
+	regval &= 0xE0;
+	regval >>= 5;
+
+	if (regval > abreg->voltages_len) {
+		dev_err(&reg->dev,
+			"regulator register %02x contains an illegal voltage setting\n",
+			abreg->regreg);
+		return -EINVAL;
+	}
+
+	return abreg->typ_voltages[regval];
+}
+
+static int ab3100_get_best_voltage_index(struct regulator_dev *reg,
+				   int min_uV, int max_uV)
+{
+	struct ab3100_regulator *abreg = reg->reg_data;
+	int i;
+	int bestmatch;
+	int bestindex;
+
+	/*
+	 * Locate the minimum voltage fitting the criteria on
+	 * this regulator. The switchable voltages are not
+	 * in strict falling order so we need to check them
+	 * all for the best match.
+	 */
+	bestmatch = INT_MAX;
+	bestindex = -1;
+	for (i = 0; i < abreg->voltages_len; i++) {
+		if (abreg->typ_voltages[i] <= max_uV &&
+		    abreg->typ_voltages[i] >= min_uV &&
+		    abreg->typ_voltages[i] < bestmatch) {
+			bestmatch = abreg->typ_voltages[i];
+			bestindex = i;
+		}
+	}
+
+	if (bestindex < 0) {
+		dev_warn(&reg->dev, "requested %d<=x<=%d uV, out of range!\n",
+			 min_uV, max_uV);
+		return -EINVAL;
+	}
+	return bestindex;
+}
+
+static int ab3100_set_voltage_regulator(struct regulator_dev *reg,
+					int min_uV, int max_uV)
+{
+	struct ab3100_regulator *abreg = reg->reg_data;
+	u8 regval;
+	int err;
+	int bestindex;
+
+	bestindex = ab3100_get_best_voltage_index(reg, min_uV, max_uV);
+	if (bestindex < 0)
+		return bestindex;
+
+	err = ab3100_get_register_interruptible(abreg->ab3100,
+						abreg->regreg, &regval);
+	if (err) {
+		dev_warn(&reg->dev,
+			 "failed to get regulator register %02x\n",
+			 abreg->regreg);
+		return err;
+	}
+
+	/* The highest three bits control the variable regulators */
+	regval &= ~0xE0;
+	regval |= (bestindex << 5);
+
+	err = ab3100_set_register_interruptible(abreg->ab3100,
+						abreg->regreg, regval);
+	if (err)
+		dev_warn(&reg->dev, "failed to set regulator register %02x\n",
+			abreg->regreg);
+
+	return err;
+}
+
+static int ab3100_set_suspend_voltage_regulator(struct regulator_dev *reg,
+						int uV)
+{
+	struct ab3100_regulator *abreg = reg->reg_data;
+	u8 regval;
+	int err;
+	int bestindex;
+	u8 targetreg;
+
+	if (abreg->regreg == AB3100_LDO_E)
+		targetreg = AB3100_LDO_E_SLEEP;
+	else if (abreg->regreg == AB3100_BUCK)
+		targetreg = AB3100_BUCK_SLEEP;
+	else
+		return -EINVAL;
+
+	/* LDO E and BUCK have special suspend voltages you can set */
+	bestindex = ab3100_get_best_voltage_index(reg, uV, uV);
+
+	err = ab3100_get_register_interruptible(abreg->ab3100,
+						targetreg, &regval);
+	if (err) {
+		dev_warn(&reg->dev,
+			 "failed to get regulator register %02x\n",
+			 targetreg);
+		return err;
+	}
+
+	/* The highest three bits control the variable regulators */
+	regval &= ~0xE0;
+	regval |= (bestindex << 5);
+
+	err = ab3100_set_register_interruptible(abreg->ab3100,
+						targetreg, regval);
+	if (err)
+		dev_warn(&reg->dev, "failed to set regulator register %02x\n",
+			abreg->regreg);
+
+	return err;
+}
+
+/*
+ * The external regulator can just define a fixed voltage.
+ */
+static int ab3100_get_voltage_regulator_external(struct regulator_dev *reg)
+{
+	struct ab3100_regulator *abreg = reg->reg_data;
+
+	return abreg->plfdata->external_voltage;
+}
+
+static struct regulator_ops regulator_ops_fixed = {
+	.enable      = ab3100_enable_regulator,
+	.disable     = ab3100_disable_regulator,
+	.is_enabled  = ab3100_is_enabled_regulator,
+	.get_voltage = ab3100_get_voltage_regulator,
+};
+
+static struct regulator_ops regulator_ops_variable = {
+	.enable      = ab3100_enable_regulator,
+	.disable     = ab3100_disable_regulator,
+	.is_enabled  = ab3100_is_enabled_regulator,
+	.get_voltage = ab3100_get_voltage_regulator,
+	.set_voltage = ab3100_set_voltage_regulator,
+	.list_voltage = ab3100_list_voltage_regulator,
+};
+
+static struct regulator_ops regulator_ops_variable_sleepable = {
+	.enable      = ab3100_enable_regulator,
+	.disable     = ab3100_disable_regulator,
+	.is_enabled  = ab3100_is_enabled_regulator,
+	.get_voltage = ab3100_get_voltage_regulator,
+	.set_voltage = ab3100_set_voltage_regulator,
+	.set_suspend_voltage = ab3100_set_suspend_voltage_regulator,
+	.list_voltage = ab3100_list_voltage_regulator,
+};
+
+/*
+ * LDO EXT is an external regulator so it is really
+ * not possible to set any voltage locally here, AB3100
+ * is an on/off switch plain an simple. The external
+ * voltage is defined in the board set-up if any.
+ */
+static struct regulator_ops regulator_ops_external = {
+	.enable      = ab3100_enable_regulator,
+	.disable     = ab3100_disable_regulator,
+	.is_enabled  = ab3100_is_enabled_regulator,
+	.get_voltage = ab3100_get_voltage_regulator_external,
+};
+
+static struct regulator_desc
+ab3100_regulator_desc[AB3100_NUM_REGULATORS] = {
+	{
+		.name = "LDO_A",
+		.id   = AB3100_LDO_A,
+		.ops  = &regulator_ops_fixed,
+		.type = REGULATOR_VOLTAGE,
+	},
+	{
+		.name = "LDO_C",
+		.id   = AB3100_LDO_C,
+		.ops  = &regulator_ops_fixed,
+		.type = REGULATOR_VOLTAGE,
+	},
+	{
+		.name = "LDO_D",
+		.id   = AB3100_LDO_D,
+		.ops  = &regulator_ops_fixed,
+		.type = REGULATOR_VOLTAGE,
+	},
+	{
+		.name = "LDO_E",
+		.id   = AB3100_LDO_E,
+		.ops  = &regulator_ops_variable_sleepable,
+		.type = REGULATOR_VOLTAGE,
+	},
+	{
+		.name = "LDO_F",
+		.id   = AB3100_LDO_F,
+		.ops  = &regulator_ops_variable,
+		.type = REGULATOR_VOLTAGE,
+	},
+	{
+		.name = "LDO_G",
+		.id   = AB3100_LDO_G,
+		.ops  = &regulator_ops_variable,
+		.type = REGULATOR_VOLTAGE,
+	},
+	{
+		.name = "LDO_H",
+		.id   = AB3100_LDO_H,
+		.ops  = &regulator_ops_variable,
+		.type = REGULATOR_VOLTAGE,
+	},
+	{
+		.name = "LDO_K",
+		.id   = AB3100_LDO_K,
+		.ops  = &regulator_ops_variable,
+		.type = REGULATOR_VOLTAGE,
+	},
+	{
+		.name = "LDO_EXT",
+		.id   = AB3100_LDO_EXT,
+		.ops  = &regulator_ops_external,
+		.type = REGULATOR_VOLTAGE,
+	},
+	{
+		.name = "BUCK",
+		.id   = AB3100_BUCK,
+		.ops  = &regulator_ops_variable_sleepable,
+		.type = REGULATOR_VOLTAGE,
+	},
+};
+
+/*
+ * NOTE: the following functions are regulators pluralis - it is the
+ * binding to the AB3100 core driver and the parent platform device
+ * for all the different regulators.
+ */
+
+static int __init ab3100_regulators_probe(struct platform_device *pdev)
+{
+	struct ab3100_platform_data *plfdata = pdev->dev.platform_data;
+	struct ab3100 *ab3100 = platform_get_drvdata(pdev);
+	int err = 0;
+	u8 data;
+	int i;
+
+	/* Check chip state */
+	err = ab3100_get_register_interruptible(ab3100,
+						AB3100_LDO_D, &data);
+	if (err) {
+		dev_err(&pdev->dev, "could not read initial status of LDO_D\n");
+		return err;
+	}
+	if (data & 0x10)
+		dev_notice(&pdev->dev,
+			   "chip is already in active mode (Warm start)\n");
+	else
+		dev_notice(&pdev->dev,
+			   "chip is in inactive mode (Cold start)\n");
+
+	/* Set up regulators */
+	for (i = 0; i < ARRAY_SIZE(ab3100_reg_init_order); i++) {
+		err = ab3100_set_register_interruptible(ab3100,
+					ab3100_reg_init_order[i],
+					plfdata->reg_initvals[i]);
+		if (err) {
+			dev_err(&pdev->dev, "regulator initialization failed with error %d\n",
+				err);
+			return err;
+		}
+	}
+
+	if (err) {
+		dev_err(&pdev->dev,
+			"LDO D regulator initialization failed with error %d\n",
+			err);
+		return err;
+	}
+
+	/* Register the regulators */
+	for (i = 0; i < AB3100_NUM_REGULATORS; i++) {
+		struct ab3100_regulator *reg = &ab3100_regulators[i];
+		struct regulator_dev *rdev;
+
+		/*
+		 * Initialize per-regulator struct.
+		 * Inherit platform data, this comes down from the
+		 * i2c boarddata, from the machine. So if you want to
+		 * see what it looks like for a certain machine, go
+		 * into the machine I2C setup.
+		 */
+		reg->ab3100 = ab3100;
+		reg->plfdata = plfdata;
+
+		/*
+		 * Register the regulator, pass around
+		 * the ab3100_regulator struct
+		 */
+		rdev = regulator_register(&ab3100_regulator_desc[i],
+					  &pdev->dev,
+					  &plfdata->reg_constraints[i],
+					  reg);
+
+		if (IS_ERR(rdev)) {
+			err = PTR_ERR(rdev);
+			dev_err(&pdev->dev,
+				"%s: failed to register regulator %s err %d\n",
+				__func__, ab3100_regulator_desc[i].name,
+				err);
+			i--;
+			/* remove the already registered regulators */
+			while (i > 0) {
+				regulator_unregister(ab3100_regulators[i].rdev);
+				i--;
+			}
+			return err;
+		}
+
+		/* Then set a pointer back to the registered regulator */
+		reg->rdev = rdev;
+	}
+
+	return 0;
+}
+
+static int __exit ab3100_regulators_remove(struct platform_device *pdev)
+{
+	int i;
+
+	for (i = 0; i < AB3100_NUM_REGULATORS; i++) {
+		struct ab3100_regulator *reg = &ab3100_regulators[i];
+
+		regulator_unregister(reg->rdev);
+	}
+	return 0;
+}
+
+static struct platform_driver ab3100_regulators_driver = {
+	.driver = {
+		.name  = "ab3100-regulators",
+		.owner = THIS_MODULE,
+	},
+	.probe = ab3100_regulators_probe,
+	.remove = __exit_p(ab3100_regulators_remove),
+};
+
+static __init int ab3100_regulators_init(void)
+{
+	return platform_driver_register(&ab3100_regulators_driver);
+}
+
+static __exit void ab3100_regulators_exit(void)
+{
+	platform_driver_register(&ab3100_regulators_driver);
+}
+
+subsys_initcall(ab3100_regulators_init);
+module_exit(ab3100_regulators_exit);
+
+MODULE_AUTHOR("Mattias Wallin <mattias.wallin@stericsson.com>");
+MODULE_DESCRIPTION("AB3100 Regulator driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:ab3100-regulators");
diff --git a/include/linux/mfd/ab3100.h b/include/linux/mfd/ab3100.h
index 56343b8..1692126 100644
--- a/include/linux/mfd/ab3100.h
+++ b/include/linux/mfd/ab3100.h
@@ -6,6 +6,7 @@
  */
 
 #include <linux/device.h>
+#include <linux/regulator/machine.h>
 
 #ifndef MFD_AB3100_H
 #define MFD_AB3100_H
@@ -56,6 +57,14 @@
 #define AB3100_STR_BATT_REMOVAL				(0x40)
 #define AB3100_STR_VBUS					(0x80)
 
+/*
+ * AB3100 contains 8 regulators, one external regulator controller
+ * and a buck converter, further the LDO E and buck converter can
+ * have separate settings if they are in sleep mode, this is
+ * modeled as a separate regulator.
+ */
+#define AB3100_NUM_REGULATORS				10
+
 /**
  * struct ab3100
  * @access_mutex: lock out concurrent accesses to the AB3100 registers
@@ -86,6 +95,25 @@ struct ab3100 {
 	bool startup_events_read;
 };
 
+/**
+ * struct ab3100_platform_data
+ * Data supplied to initialize board connections to the AB3100
+ * @reg_constraints: regulator constraints for target board
+ *     the order of these constraints are: LDO A, C, D, E,
+ *     F, G, H, K, EXT and BUCK.
+ * @reg_initvals: initial values for the regulator registers
+ *     plus two sleep settings for LDO E and the BUCK converter.
+ *     exactly AB3100_NUM_REGULATORS+2 values must be sent in.
+ *     Order: LDO A, C, E, E sleep, F, G, H, K, EXT, BUCK,
+ *     BUCK sleep, LDO D. (LDO D need to be initialized last.)
+ * @external_voltage: voltage level of the external regulator.
+ */
+struct ab3100_platform_data {
+	struct regulator_init_data reg_constraints[AB3100_NUM_REGULATORS];
+	u8 reg_initvals[AB3100_NUM_REGULATORS+2];
+	int external_voltage;
+};
+
 int ab3100_set_register_interruptible(struct ab3100 *ab3100, u8 reg, u8 regval);
 int ab3100_get_register_interruptible(struct ab3100 *ab3100, u8 reg, u8 *regval);
 int ab3100_get_register_page_interruptible(struct ab3100 *ab3100,
-- 
1.6.2.1

[PATCH 1/2] AB3100 regulator support v3

[Linus Walleij]

This adds support for the regulators found in the AB3100
Mixed-Signal IC.

It further also defines platform data for the ST-Ericsson
U300 platform and extends the AB3100 MFD driver so that
platform/board data with regulation constraints and an init
function can be passed down all the way from the board to
the regulators.

Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Liam Girdwood <lrg@slimlogic.co.uk>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Cc: Russell King <linux@arm.linux.org.uk>
---
ChangeLog v2->v3

- Fixed an embarrasing bug with comparing the best index
  for a good voltage with the iterator instead of the
  actual best index in the errorpath.

- Assign the external regulator a fixed voltage instead
  of trying to enable callbacks to the platform code.

- Pass in initdata in an u8 array with strict ordering
  which the platform code have to respect. This avoids
  the beginings of a hairy sequencing code.

- Loose the sleep mode "regulators" implement the
  set_suspend_voltage() operation instead.

- Make sure init_data to be as complete as possible before
  registering a regulator since the framework may call
  out to accessor functions during registration.
---
 drivers/mfd/ab3100-core.c  |    4 +
 drivers/regulator/Kconfig  |    9 +
 drivers/regulator/Makefile |    1 +
 drivers/regulator/ab3100.c |  694 ++++++++++++++++++++++++++++++++++++++++++++
 include/linux/mfd/ab3100.h |   28 ++
 5 files changed, 736 insertions(+), 0 deletions(-)
 create mode 100644 drivers/regulator/ab3100.c

diff --git a/drivers/mfd/ab3100-core.c b/drivers/mfd/ab3100-core.c
index 1d8ac1a..9411860 100644
--- a/drivers/mfd/ab3100-core.c
+++ b/drivers/mfd/ab3100-core.c
@@ -838,6 +838,8 @@ static int __init ab3100_probe(struct i2c_client *client,
 			const struct i2c_device_id *id)
 {
 	struct ab3100 *ab3100;
+	struct ab3100_platform_data *ab3100_plf_data =
+		client->dev.platform_data;
 	int err;
 	int i;
 
@@ -921,6 +923,8 @@ static int __init ab3100_probe(struct i2c_client *client,
 	for (i = 0; i < ARRAY_SIZE(ab3100_platform_devs); i++) {
 		ab3100_platform_devs[i]->dev.parent =
 			&client->dev;
+		ab3100_platform_devs[i]->dev.platform_data =
+			ab3100_plf_data;
 		platform_set_drvdata(ab3100_platform_devs[i], ab3100);
 	}
 
diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index 7e1b2df..33b4eba 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -154,5 +154,14 @@ config REGULATOR_TPS6507X
 	  three step-down converters and two general-purpose LDO voltage regulators.
 	  It supports TI's software based Class-2 SmartReflex implementation.
 
+config REGULATOR_AB3100
+	tristate "ST-Ericsson AB3100 Regulator functions"
+	depends on AB3100_CORE
+	default y if AB3100_CORE
+	help
+	 These regulators correspond to functionality in the
+	 AB3100 analog baseband dealing with power regulators
+	 for the system.
+
 endif
 
diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index e42745e..d1db7db 100644
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -24,5 +24,6 @@ obj-$(CONFIG_REGULATOR_MC13783) += mc13783.o
 
 obj-$(CONFIG_REGULATOR_TPS65023) += tps65023-regulator.o
 obj-$(CONFIG_REGULATOR_TPS6507X) += tps6507x-regulator.o
+obj-$(CONFIG_REGULATOR_AB3100) += ab3100.o
 
 ccflags-$(CONFIG_REGULATOR_DEBUG) += -DDEBUG
diff --git a/drivers/regulator/ab3100.c b/drivers/regulator/ab3100.c
new file mode 100644
index 0000000..156979d
--- /dev/null
+++ b/drivers/regulator/ab3100.c
@@ -0,0 +1,694 @@
+/*
+ * drivers/regulator/ab3100.c
+ *
+ * Copyright (C) 2008-2009 ST-Ericsson AB
+ * License terms: GNU General Public License (GPL) version 2
+ * Low-level control of the AB3100 IC Low Dropout (LDO)
+ * regulators, external regulator and buck converter
+ * Author: Mattias Wallin <mattias.wallin@stericsson.com>
+ * Author: Linus Walleij <linus.walleij@stericsson.com>
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/driver.h>
+#include <linux/mfd/ab3100.h>
+
+/* LDO registers and some handy masking definitions for AB3100 */
+#define AB3100_LDO_A		0x40
+#define AB3100_LDO_C		0x41
+#define AB3100_LDO_D		0x42
+#define AB3100_LDO_E		0x43
+#define AB3100_LDO_E_SLEEP	0x44
+#define AB3100_LDO_F		0x45
+#define AB3100_LDO_G		0x46
+#define AB3100_LDO_H		0x47
+#define AB3100_LDO_H_SLEEP_MODE	0
+#define AB3100_LDO_H_SLEEP_EN	2
+#define AB3100_LDO_ON		4
+#define AB3100_LDO_H_VSEL_AC	5
+#define AB3100_LDO_K		0x48
+#define AB3100_LDO_EXT		0x49
+#define AB3100_BUCK		0x4A
+#define AB3100_BUCK_SLEEP	0x4B
+#define AB3100_REG_ON_MASK	0x10
+
+/**
+ * struct ab3100_regulator
+ * A struct passed around the individual regulator functions
+ * @platform_device: platform device holding this regulator
+ * @ab3100: handle to the AB3100 parent chip
+ * @plfdata: AB3100 platform data passed in at probe time
+ * @regreg: regulator register number in the AB3100
+ * @fixed_voltage: a fixed voltage for this regulator, if this
+ *          0 the voltages array is used instead.
+ * @typ_voltages: an array of available typical voltages for
+ *          this regulator
+ * @voltages_len: length of the array of available voltages
+ */
+struct ab3100_regulator {
+	struct regulator_dev *rdev;
+	struct ab3100 *ab3100;
+	struct ab3100_platform_data *plfdata;
+	u8 regreg;
+	int fixed_voltage;
+	int const *typ_voltages;
+	u8 voltages_len;
+};
+
+/* The order in which registers are initialized */
+static const u8 ab3100_reg_init_order[AB3100_NUM_REGULATORS+2] = {
+	AB3100_LDO_A,
+	AB3100_LDO_C,
+	AB3100_LDO_E,
+	AB3100_LDO_E_SLEEP,
+	AB3100_LDO_F,
+	AB3100_LDO_G,
+	AB3100_LDO_H,
+	AB3100_LDO_K,
+	AB3100_LDO_EXT,
+	AB3100_BUCK,
+	AB3100_BUCK_SLEEP,
+	AB3100_LDO_D,
+};
+
+/* Preset (hardware defined) voltages for these regulators */
+#define LDO_A_VOLTAGE 2750000
+#define LDO_C_VOLTAGE 2650000
+#define LDO_D_VOLTAGE 2650000
+
+static const int const ldo_e_buck_typ_voltages[] = {
+	1800000,
+	1400000,
+	1300000,
+	1200000,
+	1100000,
+	1050000,
+	900000,
+};
+
+static const int const ldo_f_typ_voltages[] = {
+	1800000,
+	1400000,
+	1300000,
+	1200000,
+	1100000,
+	1050000,
+	2500000,
+	2650000,
+};
+
+static const int const ldo_g_typ_voltages[] = {
+	2850000,
+	2750000,
+	1800000,
+	1500000,
+};
+
+static const int const ldo_h_typ_voltages[] = {
+	2750000,
+	1800000,
+	1500000,
+	1200000,
+};
+
+static const int const ldo_k_typ_voltages[] = {
+	2750000,
+	1800000,
+};
+
+
+/* The regulator devices */
+static struct ab3100_regulator
+ab3100_regulators[AB3100_NUM_REGULATORS] = {
+	{
+		.regreg = AB3100_LDO_A,
+		.fixed_voltage = LDO_A_VOLTAGE,
+	},
+	{
+		.regreg = AB3100_LDO_C,
+		.fixed_voltage = LDO_C_VOLTAGE,
+	},
+	{
+		.regreg = AB3100_LDO_D,
+		.fixed_voltage = LDO_D_VOLTAGE,
+	},
+	{
+		.regreg = AB3100_LDO_E,
+		.typ_voltages = ldo_e_buck_typ_voltages,
+		.voltages_len = ARRAY_SIZE(ldo_e_buck_typ_voltages),
+	},
+	{
+		.regreg = AB3100_LDO_F,
+		.typ_voltages = ldo_f_typ_voltages,
+		.voltages_len = ARRAY_SIZE(ldo_f_typ_voltages),
+	},
+	{
+		.regreg = AB3100_LDO_G,
+		.typ_voltages = ldo_g_typ_voltages,
+		.voltages_len = ARRAY_SIZE(ldo_g_typ_voltages),
+	},
+	{
+		.regreg = AB3100_LDO_H,
+		.typ_voltages = ldo_h_typ_voltages,
+		.voltages_len = ARRAY_SIZE(ldo_h_typ_voltages),
+	},
+	{
+		.regreg = AB3100_LDO_K,
+		.typ_voltages = ldo_k_typ_voltages,
+		.voltages_len = ARRAY_SIZE(ldo_k_typ_voltages),
+	},
+	{
+		.regreg = AB3100_LDO_EXT,
+		/* No voltages for the external regulator */
+	},
+	{
+		.regreg = AB3100_BUCK,
+		.typ_voltages = ldo_e_buck_typ_voltages,
+		.voltages_len = ARRAY_SIZE(ldo_e_buck_typ_voltages),
+	},
+};
+
+/*
+ * General functions for enable, disable and is_enabled used for
+ * LDO: A,C,E,F,G,H,K,EXT and BUCK
+ */
+static int ab3100_enable_regulator(struct regulator_dev *reg)
+{
+	struct ab3100_regulator *abreg = reg->reg_data;
+	int err;
+	u8 regval;
+
+	err = ab3100_get_register_interruptible(abreg->ab3100, abreg->regreg,
+						&regval);
+	if (err) {
+		dev_warn(&reg->dev, "failed to get regid %d value\n",
+			 abreg->regreg);
+		return err;
+	}
+
+	/* The regulator is already on, no reason to go further */
+	if (regval & AB3100_REG_ON_MASK)
+		return 0;
+
+	regval |= AB3100_REG_ON_MASK;
+
+	err = ab3100_set_register_interruptible(abreg->ab3100, abreg->regreg,
+						regval);
+	if (err) {
+		dev_warn(&reg->dev, "failed to set regid %d value\n",
+			 abreg->regreg);
+		return err;
+	}
+
+	/* Per-regulator power on delay from spec */
+	switch (abreg->regreg) {
+	case AB3100_LDO_A: /* Fallthrough */
+	case AB3100_LDO_C: /* Fallthrough */
+	case AB3100_LDO_D: /* Fallthrough */
+	case AB3100_LDO_E: /* Fallthrough */
+	case AB3100_LDO_H: /* Fallthrough */
+	case AB3100_LDO_K:
+		udelay(200);
+		break;
+	case AB3100_LDO_F:
+		udelay(600);
+		break;
+	case AB3100_LDO_G:
+		udelay(400);
+		break;
+	case AB3100_BUCK:
+		mdelay(1);
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+static int ab3100_disable_regulator(struct regulator_dev *reg)
+{
+	struct ab3100_regulator *abreg = reg->reg_data;
+	int err;
+	u8 regval;
+
+	/*
+	 * LDO D is a special regulator. When it is disabled, the entire
+	 * system is shut down. So this is handled specially.
+	 */
+	if (abreg->regreg == AB3100_LDO_D) {
+		int i;
+
+		dev_info(&reg->dev, "disabling LDO D - shut down system\n");
+		/*
+		 * Set regulators to default values, ignore any errors,
+		 * we're going DOWN
+		 */
+		for (i = 0; i < ARRAY_SIZE(ab3100_reg_init_order); i++) {
+			(void) ab3100_set_register_interruptible(abreg->ab3100,
+					ab3100_reg_init_order[i],
+					abreg->plfdata->reg_initvals[i]);
+		}
+
+		/* Setting LDO D to 0x00 cuts the power to the SoC */
+		return ab3100_set_register_interruptible(abreg->ab3100,
+							 AB3100_LDO_D, 0x00U);
+
+	}
+
+	/*
+	 * All other regulators are handled here
+	 */
+	err = ab3100_get_register_interruptible(abreg->ab3100, abreg->regreg,
+						&regval);
+	if (err) {
+		dev_err(&reg->dev, "unable to get register 0x%x\n",
+			abreg->regreg);
+		return err;
+	}
+	regval &= ~AB3100_REG_ON_MASK;
+	return ab3100_set_register_interruptible(abreg->ab3100, abreg->regreg,
+						 regval);
+}
+
+static int ab3100_is_enabled_regulator(struct regulator_dev *reg)
+{
+	struct ab3100_regulator *abreg = reg->reg_data;
+	u8 regval;
+	int err;
+
+	err = ab3100_get_register_interruptible(abreg->ab3100, abreg->regreg,
+						&regval);
+	if (err) {
+		dev_err(&reg->dev, "unable to get register 0x%x\n",
+			abreg->regreg);
+		return err;
+	}
+
+	return regval & AB3100_REG_ON_MASK;
+}
+
+static int ab3100_list_voltage_regulator(struct regulator_dev *reg,
+					 unsigned selector)
+{
+	struct ab3100_regulator *abreg = reg->reg_data;
+
+	if (selector > abreg->voltages_len)
+		return -EINVAL;
+	return abreg->typ_voltages[selector];
+}
+
+static int ab3100_get_voltage_regulator(struct regulator_dev *reg)
+{
+	struct ab3100_regulator *abreg = reg->reg_data;
+	u8 regval;
+	int err;
+
+	/* Return the voltage for fixed regulators immediately */
+	if (abreg->fixed_voltage)
+		return abreg->fixed_voltage;
+
+	/*
+	 * For variable types, read out setting and index into
+	 * supplied voltage list.
+	 */
+	err = ab3100_get_register_interruptible(abreg->ab3100,
+						abreg->regreg, &regval);
+	if (err) {
+		dev_warn(&reg->dev,
+			 "failed to get regulator value in register %02x\n",
+			 abreg->regreg);
+		return err;
+	}
+
+	/* The 3 highest bits index voltages */
+	regval &= 0xE0;
+	regval >>= 5;
+
+	if (regval > abreg->voltages_len) {
+		dev_err(&reg->dev,
+			"regulator register %02x contains an illegal voltage setting\n",
+			abreg->regreg);
+		return -EINVAL;
+	}
+
+	return abreg->typ_voltages[regval];
+}
+
+static int ab3100_get_best_voltage_index(struct regulator_dev *reg,
+				   int min_uV, int max_uV)
+{
+	struct ab3100_regulator *abreg = reg->reg_data;
+	int i;
+	int bestmatch;
+	int bestindex;
+
+	/*
+	 * Locate the minimum voltage fitting the criteria on
+	 * this regulator. The switchable voltages are not
+	 * in strict falling order so we need to check them
+	 * all for the best match.
+	 */
+	bestmatch = INT_MAX;
+	bestindex = -1;
+	for (i = 0; i < abreg->voltages_len; i++) {
+		if (abreg->typ_voltages[i] <= max_uV &&
+		    abreg->typ_voltages[i] >= min_uV &&
+		    abreg->typ_voltages[i] < bestmatch) {
+			bestmatch = abreg->typ_voltages[i];
+			bestindex = i;
+		}
+	}
+
+	if (bestindex < 0) {
+		dev_warn(&reg->dev, "requested %d<=x<=%d uV, out of range!\n",
+			 min_uV, max_uV);
+		return -EINVAL;
+	}
+	return bestindex;
+}
+
+static int ab3100_set_voltage_regulator(struct regulator_dev *reg,
+					int min_uV, int max_uV)
+{
+	struct ab3100_regulator *abreg = reg->reg_data;
+	u8 regval;
+	int err;
+	int bestindex;
+
+	bestindex = ab3100_get_best_voltage_index(reg, min_uV, max_uV);
+	if (bestindex < 0)
+		return bestindex;
+
+	err = ab3100_get_register_interruptible(abreg->ab3100,
+						abreg->regreg, &regval);
+	if (err) {
+		dev_warn(&reg->dev,
+			 "failed to get regulator register %02x\n",
+			 abreg->regreg);
+		return err;
+	}
+
+	/* The highest three bits control the variable regulators */
+	regval &= ~0xE0;
+	regval |= (bestindex << 5);
+
+	err = ab3100_set_register_interruptible(abreg->ab3100,
+						abreg->regreg, regval);
+	if (err)
+		dev_warn(&reg->dev, "failed to set regulator register %02x\n",
+			abreg->regreg);
+
+	return err;
+}
+
+static int ab3100_set_suspend_voltage_regulator(struct regulator_dev *reg,
+						int uV)
+{
+	struct ab3100_regulator *abreg = reg->reg_data;
+	u8 regval;
+	int err;
+	int bestindex;
+	u8 targetreg;
+
+	if (abreg->regreg == AB3100_LDO_E)
+		targetreg = AB3100_LDO_E_SLEEP;
+	else if (abreg->regreg == AB3100_BUCK)
+		targetreg = AB3100_BUCK_SLEEP;
+	else
+		return -EINVAL;
+
+	/* LDO E and BUCK have special suspend voltages you can set */
+	bestindex = ab3100_get_best_voltage_index(reg, uV, uV);
+
+	err = ab3100_get_register_interruptible(abreg->ab3100,
+						targetreg, &regval);
+	if (err) {
+		dev_warn(&reg->dev,
+			 "failed to get regulator register %02x\n",
+			 targetreg);
+		return err;
+	}
+
+	/* The highest three bits control the variable regulators */
+	regval &= ~0xE0;
+	regval |= (bestindex << 5);
+
+	err = ab3100_set_register_interruptible(abreg->ab3100,
+						targetreg, regval);
+	if (err)
+		dev_warn(&reg->dev, "failed to set regulator register %02x\n",
+			abreg->regreg);
+
+	return err;
+}
+
+/*
+ * The external regulator can just define a fixed voltage.
+ */
+static int ab3100_get_voltage_regulator_external(struct regulator_dev *reg)
+{
+	struct ab3100_regulator *abreg = reg->reg_data;
+
+	return abreg->plfdata->external_voltage;
+}
+
+static struct regulator_ops regulator_ops_fixed = {
+	.enable      = ab3100_enable_regulator,
+	.disable     = ab3100_disable_regulator,
+	.is_enabled  = ab3100_is_enabled_regulator,
+	.get_voltage = ab3100_get_voltage_regulator,
+};
+
+static struct regulator_ops regulator_ops_variable = {
+	.enable      = ab3100_enable_regulator,
+	.disable     = ab3100_disable_regulator,
+	.is_enabled  = ab3100_is_enabled_regulator,
+	.get_voltage = ab3100_get_voltage_regulator,
+	.set_voltage = ab3100_set_voltage_regulator,
+	.list_voltage = ab3100_list_voltage_regulator,
+};
+
+static struct regulator_ops regulator_ops_variable_sleepable = {
+	.enable      = ab3100_enable_regulator,
+	.disable     = ab3100_disable_regulator,
+	.is_enabled  = ab3100_is_enabled_regulator,
+	.get_voltage = ab3100_get_voltage_regulator,
+	.set_voltage = ab3100_set_voltage_regulator,
+	.set_suspend_voltage = ab3100_set_suspend_voltage_regulator,
+	.list_voltage = ab3100_list_voltage_regulator,
+};
+
+/*
+ * LDO EXT is an external regulator so it is really
+ * not possible to set any voltage locally here, AB3100
+ * is an on/off switch plain an simple. The external
+ * voltage is defined in the board set-up if any.
+ */
+static struct regulator_ops regulator_ops_external = {
+	.enable      = ab3100_enable_regulator,
+	.disable     = ab3100_disable_regulator,
+	.is_enabled  = ab3100_is_enabled_regulator,
+	.get_voltage = ab3100_get_voltage_regulator_external,
+};
+
+static struct regulator_desc
+ab3100_regulator_desc[AB3100_NUM_REGULATORS] = {
+	{
+		.name = "LDO_A",
+		.id   = AB3100_LDO_A,
+		.ops  = &regulator_ops_fixed,
+		.type = REGULATOR_VOLTAGE,
+	},
+	{
+		.name = "LDO_C",
+		.id   = AB3100_LDO_C,
+		.ops  = &regulator_ops_fixed,
+		.type = REGULATOR_VOLTAGE,
+	},
+	{
+		.name = "LDO_D",
+		.id   = AB3100_LDO_D,
+		.ops  = &regulator_ops_fixed,
+		.type = REGULATOR_VOLTAGE,
+	},
+	{
+		.name = "LDO_E",
+		.id   = AB3100_LDO_E,
+		.ops  = &regulator_ops_variable_sleepable,
+		.type = REGULATOR_VOLTAGE,
+	},
+	{
+		.name = "LDO_F",
+		.id   = AB3100_LDO_F,
+		.ops  = &regulator_ops_variable,
+		.type = REGULATOR_VOLTAGE,
+	},
+	{
+		.name = "LDO_G",
+		.id   = AB3100_LDO_G,
+		.ops  = &regulator_ops_variable,
+		.type = REGULATOR_VOLTAGE,
+	},
+	{
+		.name = "LDO_H",
+		.id   = AB3100_LDO_H,
+		.ops  = &regulator_ops_variable,
+		.type = REGULATOR_VOLTAGE,
+	},
+	{
+		.name = "LDO_K",
+		.id   = AB3100_LDO_K,
+		.ops  = &regulator_ops_variable,
+		.type = REGULATOR_VOLTAGE,
+	},
+	{
+		.name = "LDO_EXT",
+		.id   = AB3100_LDO_EXT,
+		.ops  = &regulator_ops_external,
+		.type = REGULATOR_VOLTAGE,
+	},
+	{
+		.name = "BUCK",
+		.id   = AB3100_BUCK,
+		.ops  = &regulator_ops_variable_sleepable,
+		.type = REGULATOR_VOLTAGE,
+	},
+};
+
+/*
+ * NOTE: the following functions are regulators pluralis - it is the
+ * binding to the AB3100 core driver and the parent platform device
+ * for all the different regulators.
+ */
+
+static int __init ab3100_regulators_probe(struct platform_device *pdev)
+{
+	struct ab3100_platform_data *plfdata = pdev->dev.platform_data;
+	struct ab3100 *ab3100 = platform_get_drvdata(pdev);
+	int err = 0;
+	u8 data;
+	int i;
+
+	/* Check chip state */
+	err = ab3100_get_register_interruptible(ab3100,
+						AB3100_LDO_D, &data);
+	if (err) {
+		dev_err(&pdev->dev, "could not read initial status of LDO_D\n");
+		return err;
+	}
+	if (data & 0x10)
+		dev_notice(&pdev->dev,
+			   "chip is already in active mode (Warm start)\n");
+	else
+		dev_notice(&pdev->dev,
+			   "chip is in inactive mode (Cold start)\n");
+
+	/* Set up regulators */
+	for (i = 0; i < ARRAY_SIZE(ab3100_reg_init_order); i++) {
+		err = ab3100_set_register_interruptible(ab3100,
+					ab3100_reg_init_order[i],
+					plfdata->reg_initvals[i]);
+		if (err) {
+			dev_err(&pdev->dev, "regulator initialization failed with error %d\n",
+				err);
+			return err;
+		}
+	}
+
+	if (err) {
+		dev_err(&pdev->dev,
+			"LDO D regulator initialization failed with error %d\n",
+			err);
+		return err;
+	}
+
+	/* Register the regulators */
+	for (i = 0; i < AB3100_NUM_REGULATORS; i++) {
+		struct ab3100_regulator *reg = &ab3100_regulators[i];
+		struct regulator_dev *rdev;
+
+		/*
+		 * Initialize per-regulator struct.
+		 * Inherit platform data, this comes down from the
+		 * i2c boarddata, from the machine. So if you want to
+		 * see what it looks like for a certain machine, go
+		 * into the machine I2C setup.
+		 */
+		reg->ab3100 = ab3100;
+		reg->plfdata = plfdata;
+
+		/*
+		 * Register the regulator, pass around
+		 * the ab3100_regulator struct
+		 */
+		rdev = regulator_register(&ab3100_regulator_desc[i],
+					  &pdev->dev,
+					  &plfdata->reg_constraints[i],
+					  reg);
+
+		if (IS_ERR(rdev)) {
+			err = PTR_ERR(rdev);
+			dev_err(&pdev->dev,
+				"%s: failed to register regulator %s err %d\n",
+				__func__, ab3100_regulator_desc[i].name,
+				err);
+			i--;
+			/* remove the already registered regulators */
+			while (i > 0) {
+				regulator_unregister(ab3100_regulators[i].rdev);
+				i--;
+			}
+			return err;
+		}
+
+		/* Then set a pointer back to the registered regulator */
+		reg->rdev = rdev;
+	}
+
+	return 0;
+}
+
+static int __exit ab3100_regulators_remove(struct platform_device *pdev)
+{
+	int i;
+
+	for (i = 0; i < AB3100_NUM_REGULATORS; i++) {
+		struct ab3100_regulator *reg = &ab3100_regulators[i];
+
+		regulator_unregister(reg->rdev);
+	}
+	return 0;
+}
+
+static struct platform_driver ab3100_regulators_driver = {
+	.driver = {
+		.name  = "ab3100-regulators",
+		.owner = THIS_MODULE,
+	},
+	.probe = ab3100_regulators_probe,
+	.remove = __exit_p(ab3100_regulators_remove),
+};
+
+static __init int ab3100_regulators_init(void)
+{
+	return platform_driver_register(&ab3100_regulators_driver);
+}
+
+static __exit void ab3100_regulators_exit(void)
+{
+	platform_driver_register(&ab3100_regulators_driver);
+}
+
+subsys_initcall(ab3100_regulators_init);
+module_exit(ab3100_regulators_exit);
+
+MODULE_AUTHOR("Mattias Wallin <mattias.wallin@stericsson.com>");
+MODULE_DESCRIPTION("AB3100 Regulator driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:ab3100-regulators");
diff --git a/include/linux/mfd/ab3100.h b/include/linux/mfd/ab3100.h
index 56343b8..1692126 100644
--- a/include/linux/mfd/ab3100.h
+++ b/include/linux/mfd/ab3100.h
@@ -6,6 +6,7 @@
  */
 
 #include <linux/device.h>
+#include <linux/regulator/machine.h>
 
 #ifndef MFD_AB3100_H
 #define MFD_AB3100_H
@@ -56,6 +57,14 @@
 #define AB3100_STR_BATT_REMOVAL				(0x40)
 #define AB3100_STR_VBUS					(0x80)
 
+/*
+ * AB3100 contains 8 regulators, one external regulator controller
+ * and a buck converter, further the LDO E and buck converter can
+ * have separate settings if they are in sleep mode, this is
+ * modeled as a separate regulator.
+ */
+#define AB3100_NUM_REGULATORS				10
+
 /**
  * struct ab3100
  * @access_mutex: lock out concurrent accesses to the AB3100 registers
@@ -86,6 +95,25 @@ struct ab3100 {
 	bool startup_events_read;
 };
 
+/**
+ * struct ab3100_platform_data
+ * Data supplied to initialize board connections to the AB3100
+ * @reg_constraints: regulator constraints for target board
+ *     the order of these constraints are: LDO A, C, D, E,
+ *     F, G, H, K, EXT and BUCK.
+ * @reg_initvals: initial values for the regulator registers
+ *     plus two sleep settings for LDO E and the BUCK converter.
+ *     exactly AB3100_NUM_REGULATORS+2 values must be sent in.
+ *     Order: LDO A, C, E, E sleep, F, G, H, K, EXT, BUCK,
+ *     BUCK sleep, LDO D. (LDO D need to be initialized last.)
+ * @external_voltage: voltage level of the external regulator.
+ */
+struct ab3100_platform_data {
+	struct regulator_init_data reg_constraints[AB3100_NUM_REGULATORS];
+	u8 reg_initvals[AB3100_NUM_REGULATORS+2];
+	int external_voltage;
+};
+
 int ab3100_set_register_interruptible(struct ab3100 *ab3100, u8 reg, u8 regval);
 int ab3100_get_register_interruptible(struct ab3100 *ab3100, u8 reg, u8 *regval);
 int ab3100_get_register_page_interruptible(struct ab3100 *ab3100,
-- 
1.6.2.1

Re: [PATCH 1/2] AB3100 regulator support v3

[Mark Brown]

On Tue, Sep 01, 2009 at 12:04:18AM +0200, Linus Walleij wrote:
> This adds support for the regulators found in the AB3100
> Mixed-Signal IC.
> 
> It further also defines platform data for the ST-Ericsson
> U300 platform and extends the AB3100 MFD driver so that
> platform/board data with regulation constraints and an init
> function can be passed down all the way from the board to
> the regulators.
> 
> Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>

This looks basically good - my only concern is if the initialisation
data supplied for the regulators is just setting up the things that can
be set up via the API or if there's other stuff going on (this was my
reason for the question I asked the other day).  If there's other stuff
being configured then I'm happy with the patch modulo the static thing.

[PATCH 1/2] AB3100 regulator support v3

[Mark Brown]

On Tue, Sep 01, 2009 at 12:04:18AM +0200, Linus Walleij wrote:
> This adds support for the regulators found in the AB3100
> Mixed-Signal IC.
> 
> It further also defines platform data for the ST-Ericsson
> U300 platform and extends the AB3100 MFD driver so that
> platform/board data with regulation constraints and an init
> function can be passed down all the way from the board to
> the regulators.
> 
> Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>

This looks basically good - my only concern is if the initialisation
data supplied for the regulators is just setting up the things that can
be set up via the API or if there's other stuff going on (this was my
reason for the question I asked the other day).  If there's other stuff
being configured then I'm happy with the patch modulo the static thing.

Re: [PATCH 1/2] AB3100 regulator support v3

[Linus Walleij]

2009/9/2 Mark Brown <broonie@opensource.wolfsonmicro.com>:

> This looks basically good - my only concern is if the initialisation
> data supplied for the regulators is just setting up the things that can
> be set up via the API or if there's other stuff going on (this was my
> reason for the question I asked the other day).  If there's other stuff
> being configured then I'm happy with the patch modulo the static thing.

OK so this array:

+       /* Set up regulators */
+       for (i = 0; i < ARRAY_SIZE(ab3100_reg_init_order); i++) {
+               err = ab3100_set_register_interruptible(ab3100,
+                                       ab3100_reg_init_order[i],
+                                       plfdata->reg_initvals[i]);

The initvals are one-byte registers for each regulator plus 2 bytes
of sleep settings for LDO E and BUCK respectively.

The sleep settings are driven by two HW lines, so a regulator
can react by suspending the regulator on line A or B disjunct
either (logical ||) or both (logical &&). (You don't alter that in
runtime so no API has been developed here.)

Apart from that it's just default-zero undefined bits and default
voltage and default on/off setting. It is mainly written here so
that we have a known state, eventhough the boot loader should
have set them up (thus boot_on for some of them). But I like
to be on the safe side. If you for example download the kernel
through something like JTAG you may not have executed the
boot loader, and the reset power-on defaults can be bad,
for example have regulators enabled that should not be.

Currently the framework will enable the .boot_on regulators
effectively setting this one bit right for all regulators.

For *some* of the boot_on regulators I could also use .apply_uV
to set the voltage bits of course, but only if min_uV
and max_uV is the same which is not the case for all
regulators that are default on here.

And I don't see any way for the core (set_machine_constraints)
to set regulators to *off* by default if they happen to be on at
boot.

So my conclusion is that the array of initial settings is really
needed to:

- Set sleep config bits (you don't want to alter this runtime BTW)
- Set some default voltage levels on variable regulators
- Set some regulators default off
- Thus establish a known initial state

OK?

Yours,
Linus Walleij

[PATCH 1/2] AB3100 regulator support v3

[Linus Walleij]

2009/9/2 Mark Brown <broonie@opensource.wolfsonmicro.com>:

> This looks basically good - my only concern is if the initialisation
> data supplied for the regulators is just setting up the things that can
> be set up via the API or if there's other stuff going on (this was my
> reason for the question I asked the other day). ?If there's other stuff
> being configured then I'm happy with the patch modulo the static thing.

OK so this array:

+       /* Set up regulators */
+       for (i = 0; i < ARRAY_SIZE(ab3100_reg_init_order); i++) {
+               err = ab3100_set_register_interruptible(ab3100,
+                                       ab3100_reg_init_order[i],
+                                       plfdata->reg_initvals[i]);

The initvals are one-byte registers for each regulator plus 2 bytes
of sleep settings for LDO E and BUCK respectively.

The sleep settings are driven by two HW lines, so a regulator
can react by suspending the regulator on line A or B disjunct
either (logical ||) or both (logical &&). (You don't alter that in
runtime so no API has been developed here.)

Apart from that it's just default-zero undefined bits and default
voltage and default on/off setting. It is mainly written here so
that we have a known state, eventhough the boot loader should
have set them up (thus boot_on for some of them). But I like
to be on the safe side. If you for example download the kernel
through something like JTAG you may not have executed the
boot loader, and the reset power-on defaults can be bad,
for example have regulators enabled that should not be.

Currently the framework will enable the .boot_on regulators
effectively setting this one bit right for all regulators.

For *some* of the boot_on regulators I could also use .apply_uV
to set the voltage bits of course, but only if min_uV
and max_uV is the same which is not the case for all
regulators that are default on here.

And I don't see any way for the core (set_machine_constraints)
to set regulators to *off* by default if they happen to be on at
boot.

So my conclusion is that the array of initial settings is really
needed to:

- Set sleep config bits (you don't want to alter this runtime BTW)
- Set some default voltage levels on variable regulators
- Set some regulators default off
- Thus establish a known initial state

OK?

Yours,
Linus Walleij

Re: [PATCH 1/2] AB3100 regulator support v3

[Mark Brown]

On Wed, Sep 02, 2009 at 11:37:00PM +0200, Linus Walleij wrote:

> The sleep settings are driven by two HW lines, so a regulator
> can react by suspending the regulator on line A or B disjunct
> either (logical ||) or both (logical &&). (You don't alter that in
> runtime so no API has been developed here.)

OK, that's fine - it's setting things outside the normal API flow which
is all that I was asking.

> And I don't see any way for the core (set_machine_constraints)
> to set regulators to *off* by default if they happen to be on at
> boot.

That'd be a boot_off constraint if someone requires it.  So far nobody
has - there's not going to be many cases where it's appropriate to do
so, normally either you want to leave the supplies on for the device
driver that's taking control of the device or it does no harm to wait
till the end of init.

[PATCH 1/2] AB3100 regulator support v3

[Mark Brown]

On Wed, Sep 02, 2009 at 11:37:00PM +0200, Linus Walleij wrote:

> The sleep settings are driven by two HW lines, so a regulator
> can react by suspending the regulator on line A or B disjunct
> either (logical ||) or both (logical &&). (You don't alter that in
> runtime so no API has been developed here.)

OK, that's fine - it's setting things outside the normal API flow which
is all that I was asking.

> And I don't see any way for the core (set_machine_constraints)
> to set regulators to *off* by default if they happen to be on at
> boot.

That'd be a boot_off constraint if someone requires it.  So far nobody
has - there's not going to be many cases where it's appropriate to do
so, normally either you want to leave the supplies on for the device
driver that's taking control of the device or it does no harm to wait
till the end of init.