regulator: Bypass mode support

Allow regulators to be put into a non-regulating mode bypassing the
 input straight to the output, mostly used by low power retention modes.
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Merge tag 'bypass' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator into for-3.7

regulator: Bypass mode support

Allow regulators to be put into a non-regulating mode bypassing the
input straight to the output, mostly used by low power retention modes.

Documentation/ABI/testing/sysfs-class-regulator

@@ -349,3 +349,24 @@ Description:
 
 		This will be one of the same strings reported by
 		the "state" attribute.
+
+What:		/sys/class/regulator/.../bypass
+Date:		September 2012
+KernelVersion:	3.7
+Contact:	Mark Brown <broonie@opensource.wolfsonmicro.com>
+Description:
+		Some regulator directories will contain a field called
+		bypass.  This indicates if the device is in bypass mode.
+
+		This will be one of the following strings:
+
+		'enabled'
+		'disabled'
+		'unknown'
+
+		'enabled' means the regulator is in bypass mode.
+
+		'disabled' means that the regulator is regulating.
+
+		'unknown' means software cannot determine the state, or
+		the reported state is invalid.

drivers/extcon/extcon-arizona.c

@@ -434,6 +434,11 @@ static int __devinit arizona_extcon_probe(struct platform_device *pdev)
 	regmap_update_bits(arizona->regmap, ARIZONA_JACK_DETECT_ANALOGUE,
 			   ARIZONA_JD1_ENA, ARIZONA_JD1_ENA);
 
+	ret = regulator_allow_bypass(info->micvdd, true);
+	if (ret != 0)
+		dev_warn(arizona->dev, "Failed to set MICVDD to bypass: %d\n",
+			 ret);
+
 	pm_runtime_put(&pdev->dev);
 
 	return 0;

drivers/regulator/arizona-ldo1.c

@@ -39,6 +39,8 @@ static struct regulator_ops arizona_ldo1_ops = {
 	.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,
 };
 
 static const struct regulator_desc arizona_ldo1 = {
@@ -49,6 +51,8 @@ static const struct regulator_desc arizona_ldo1 = {
 
 	.vsel_reg = ARIZONA_LDO1_CONTROL_1,
 	.vsel_mask = ARIZONA_LDO1_VSEL_MASK,
+	.bypass_reg = ARIZONA_LDO1_CONTROL_1,
+	.bypass_mask = ARIZONA_LDO1_BYPASS,
 	.min_uV = 900000,
 	.uV_step = 50000,
 	.n_voltages = 7,

drivers/regulator/arizona-micsupp.c

@@ -82,6 +82,9 @@ static struct regulator_ops arizona_micsupp_ops = {
 
 	.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,
 };
 
 static const struct regulator_desc arizona_micsupp = {
@@ -95,6 +98,8 @@ static const struct regulator_desc arizona_micsupp = {
 	.vsel_mask = ARIZONA_LDO2_VSEL_MASK,
 	.enable_reg = ARIZONA_MIC_CHARGE_PUMP_1,
 	.enable_mask = ARIZONA_CPMIC_ENA,
+	.bypass_reg = ARIZONA_MIC_CHARGE_PUMP_1,
+	.bypass_mask = ARIZONA_CPMIC_BYPASS,
 
 	.owner = THIS_MODULE,
 };

drivers/regulator/core.c

@@ -77,6 +77,7 @@ struct regulator {
 	struct device *dev;
 	struct list_head list;
 	unsigned int always_on:1;
+	unsigned int bypass:1;
 	int uA_load;
 	int min_uV;
 	int max_uV;
@@ -394,6 +395,9 @@ static ssize_t regulator_status_show(struct device *dev,
 	case REGULATOR_STATUS_STANDBY:
 		label = "standby";
 		break;
+	case REGULATOR_STATUS_BYPASS:
+		label = "bypass";
+		break;
 	case REGULATOR_STATUS_UNDEFINED:
 		label = "undefined";
 		break;
@@ -585,6 +589,27 @@ static ssize_t regulator_suspend_standby_state_show(struct device *dev,
 static DEVICE_ATTR(suspend_standby_state, 0444,
 		regulator_suspend_standby_state_show, NULL);
 
+static ssize_t regulator_bypass_show(struct device *dev,
+				     struct device_attribute *attr, char *buf)
+{
+	struct regulator_dev *rdev = dev_get_drvdata(dev);
+	const char *report;
+	bool bypass;
+	int ret;
+
+	ret = rdev->desc->ops->get_bypass(rdev, &bypass);
+
+	if (ret != 0)
+		report = "unknown";
+	else if (bypass)
+		report = "enabled";
+	else
+		report = "disabled";
+
+	return sprintf(buf, "%s\n", report);
+}
+static DEVICE_ATTR(bypass, 0444,
+		   regulator_bypass_show, NULL);
 
 /*
  * These are the only attributes are present for all regulators.
@@ -2673,6 +2698,100 @@ int regulator_set_optimum_mode(struct regulator *regulator, int uA_load)
 }
 EXPORT_SYMBOL_GPL(regulator_set_optimum_mode);
 
+/**
+ * regulator_set_bypass_regmap - Default set_bypass() using regmap
+ *
+ * @rdev: device to operate on.
+ * @enable: state to set.
+ */
+int regulator_set_bypass_regmap(struct regulator_dev *rdev, bool enable)
+{
+	unsigned int val;
+
+	if (enable)
+		val = rdev->desc->bypass_mask;
+	else
+		val = 0;
+
+	return regmap_update_bits(rdev->regmap, rdev->desc->bypass_reg,
+				  rdev->desc->bypass_mask, val);
+}
+EXPORT_SYMBOL_GPL(regulator_set_bypass_regmap);
+
+/**
+ * regulator_get_bypass_regmap - Default get_bypass() using regmap
+ *
+ * @rdev: device to operate on.
+ * @enable: current state.
+ */
+int regulator_get_bypass_regmap(struct regulator_dev *rdev, bool *enable)
+{
+	unsigned int val;
+	int ret;
+
+	ret = regmap_read(rdev->regmap, rdev->desc->bypass_reg, &val);
+	if (ret != 0)
+		return ret;
+
+	*enable = val & rdev->desc->bypass_mask;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(regulator_get_bypass_regmap);
+
+/**
+ * regulator_allow_bypass - allow the regulator to go into bypass mode
+ *
+ * @regulator: Regulator to configure
+ * @allow: enable or disable bypass mode
+ *
+ * Allow the regulator to go into bypass mode if all other consumers
+ * for the regulator also enable bypass mode and the machine
+ * constraints allow this.  Bypass mode means that the regulator is
+ * simply passing the input directly to the output with no regulation.
+ */
+int regulator_allow_bypass(struct regulator *regulator, bool enable)
+{
+	struct regulator_dev *rdev = regulator->rdev;
+	int ret = 0;
+
+	if (!rdev->desc->ops->set_bypass)
+		return 0;
+
+	if (rdev->constraints &&
+	    !(rdev->constraints->valid_ops_mask & REGULATOR_CHANGE_BYPASS))
+		return 0;
+
+	mutex_lock(&rdev->mutex);
+
+	if (enable && !regulator->bypass) {
+		rdev->bypass_count++;
+
+		if (rdev->bypass_count == rdev->open_count) {
+			ret = rdev->desc->ops->set_bypass(rdev, enable);
+			if (ret != 0)
+				rdev->bypass_count--;
+		}
+
+	} else if (!enable && regulator->bypass) {
+		rdev->bypass_count--;
+
+		if (rdev->bypass_count != rdev->open_count) {
+			ret = rdev->desc->ops->set_bypass(rdev, enable);
+			if (ret != 0)
+				rdev->bypass_count++;
+		}
+	}
+
+	if (ret == 0)
+		regulator->bypass = enable;
+
+	mutex_unlock(&rdev->mutex);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(regulator_allow_bypass);
+
 /**
  * regulator_register_notifier - register regulator event notifier
  * @regulator: regulator source
@@ -3036,6 +3155,11 @@ static int add_regulator_attributes(struct regulator_dev *rdev)
 		if (status < 0)
 			return status;
 	}
+	if (ops->get_bypass) {
+		status = device_create_file(dev, &dev_attr_bypass);
+		if (status < 0)
+			return status;
+	}
 
 	/* some attributes are type-specific */
 	if (rdev->desc->type == REGULATOR_CURRENT) {
@@ -3124,6 +3248,8 @@ static void rdev_init_debugfs(struct regulator_dev *rdev)
 			   &rdev->use_count);
 	debugfs_create_u32("open_count", 0444, rdev->debugfs,
 			   &rdev->open_count);
+	debugfs_create_u32("bypass_count", 0444, rdev->debugfs,
+			   &rdev->bypass_count);
 }
 
 /**

drivers/regulator/wm831x-ldo.c

@@ -237,6 +237,8 @@ static struct regulator_ops wm831x_gp_ldo_ops = {
 	.set_mode = wm831x_gp_ldo_set_mode,
 	.get_status = wm831x_gp_ldo_get_status,
 	.get_optimum_mode = wm831x_gp_ldo_get_optimum_mode,
+	.get_bypass = regulator_get_bypass_regmap,
+	.set_bypass = regulator_set_bypass_regmap,
 
 	.is_enabled = regulator_is_enabled_regmap,
 	.enable = regulator_enable_regmap,
@@ -293,6 +295,8 @@ static __devinit int wm831x_gp_ldo_probe(struct platform_device *pdev)
 	ldo->desc.vsel_mask = WM831X_LDO1_ON_VSEL_MASK;
 	ldo->desc.enable_reg = WM831X_LDO_ENABLE;
 	ldo->desc.enable_mask = 1 << id;
+	ldo->desc.bypass_reg = ldo->base;
+	ldo->desc.bypass_mask = WM831X_LDO1_SWI;
 
 	config.dev = pdev->dev.parent;
 	if (pdata)
@@ -488,6 +492,8 @@ static struct regulator_ops wm831x_aldo_ops = {
 	.get_mode = wm831x_aldo_get_mode,
 	.set_mode = wm831x_aldo_set_mode,
 	.get_status = wm831x_aldo_get_status,
+	.set_bypass = regulator_set_bypass_regmap,
+	.get_bypass = regulator_get_bypass_regmap,
 
 	.is_enabled = regulator_is_enabled_regmap,
 	.enable = regulator_enable_regmap,
@@ -544,6 +550,8 @@ static __devinit int wm831x_aldo_probe(struct platform_device *pdev)
 	ldo->desc.vsel_mask = WM831X_LDO7_ON_VSEL_MASK;
 	ldo->desc.enable_reg = WM831X_LDO_ENABLE;
 	ldo->desc.enable_mask = 1 << id;
+	ldo->desc.bypass_reg = ldo->base;
+	ldo->desc.bypass_mask = WM831X_LDO7_SWI;
 
 	config.dev = pdev->dev.parent;
 	if (pdata)

include/linux/regulator/consumer.h

@@ -177,6 +177,8 @@ int regulator_set_mode(struct regulator *regulator, unsigned int mode);
 unsigned int regulator_get_mode(struct regulator *regulator);
 int regulator_set_optimum_mode(struct regulator *regulator, int load_uA);
 
+int regulator_allow_bypass(struct regulator *regulator, bool allow);
+
 /* regulator notifier block */
 int regulator_register_notifier(struct regulator *regulator,
 			      struct notifier_block *nb);
@@ -328,6 +330,12 @@ static inline int regulator_set_optimum_mode(struct regulator *regulator,
 	return REGULATOR_MODE_NORMAL;
 }
 
+static inline int regulator_allow_bypass(struct regulator *regulator,
+					 bool allow)
+{
+	return 0;
+}
+
 static inline int regulator_register_notifier(struct regulator *regulator,
 			      struct notifier_block *nb)
 {

include/linux/regulator/driver.h

@@ -32,6 +32,8 @@ enum regulator_status {
 	REGULATOR_STATUS_NORMAL,
 	REGULATOR_STATUS_IDLE,
 	REGULATOR_STATUS_STANDBY,
+	/* The regulator is enabled but not regulating */
+	REGULATOR_STATUS_BYPASS,
 	/* in case that any other status doesn't apply */
 	REGULATOR_STATUS_UNDEFINED,
 };
@@ -67,6 +69,9 @@ enum regulator_status {
  * @get_optimum_mode: Get the most efficient operating mode for the regulator
  *                    when running with the specified parameters.
  *
+ * @set_bypass: Set the regulator in bypass mode.
+ * @get_bypass: Get the regulator bypass mode state.
+ *
  * @enable_time: Time taken for the regulator voltage output voltage to
  *               stabilise after being enabled, in microseconds.
  * @set_ramp_delay: Set the ramp delay for the regulator. The driver should
@@ -133,6 +138,10 @@ struct regulator_ops {
 	unsigned int (*get_optimum_mode) (struct regulator_dev *, int input_uV,
 					  int output_uV, int load_uA);
 
+	/* control and report on bypass mode */
+	int (*set_bypass)(struct regulator_dev *dev, bool enable);
+	int (*get_bypass)(struct regulator_dev *dev, bool *enable);
+
 	/* the operations below are for configuration of regulator state when
 	 * its parent PMIC enters a global STANDBY/HIBERNATE state */
 
@@ -205,6 +214,8 @@ struct regulator_desc {
 	unsigned int vsel_mask;
 	unsigned int enable_reg;
 	unsigned int enable_mask;
+	unsigned int bypass_reg;
+	unsigned int bypass_mask;
 
 	unsigned int enable_time;
 };
@@ -253,6 +264,7 @@ struct regulator_dev {
 	int exclusive;
 	u32 use_count;
 	u32 open_count;
+	u32 bypass_count;
 
 	/* lists we belong to */
 	struct list_head list; /* list of all regulators */
@@ -310,6 +322,8 @@ int regulator_disable_regmap(struct regulator_dev *rdev);
 int regulator_set_voltage_time_sel(struct regulator_dev *rdev,
 				   unsigned int old_selector,
 				   unsigned int new_selector);
+int regulator_set_bypass_regmap(struct regulator_dev *rdev, bool enable);
+int regulator_get_bypass_regmap(struct regulator_dev *rdev, bool *enable);
 
 void *regulator_get_init_drvdata(struct regulator_init_data *reg_init_data);
 

include/linux/regulator/machine.h

@@ -32,6 +32,7 @@ struct regulator;
  *           board/machine.
  * STATUS:   Regulator can be enabled and disabled.
  * DRMS:     Dynamic Regulator Mode Switching is enabled for this regulator.
+ * BYPASS:   Regulator can be put into bypass mode
  */
 
 #define REGULATOR_CHANGE_VOLTAGE	0x1
@@ -39,6 +40,7 @@ struct regulator;
 #define REGULATOR_CHANGE_MODE		0x4
 #define REGULATOR_CHANGE_STATUS		0x8
 #define REGULATOR_CHANGE_DRMS		0x10
+#define REGULATOR_CHANGE_BYPASS		0x20
 
 /**
  * struct regulator_state - regulator state during low power system states