regulator: Add helpers for low-level register access
Add helper functions that allow regulator consumers to obtain low-level
details about the regulator hardware, like the voltage selector register
address and such. These details can be useful when configuring hardware
or firmware that want to do low-level access to regulators, with no
involvement from the kernel.
The use-case for Tegra is a voltage-controlled oscillator clocksource
which has control logic to change the supply voltage via I2C to achieve
a desired output clock rate.
Signed-off-by: Tuomas Tynkkynen <ttynkkynen@nvidia.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 4c1f999..486b590 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -2222,6 +2222,77 @@
EXPORT_SYMBOL_GPL(regulator_list_voltage);
/**
+ * regulator_get_regmap - get the regulator's register map
+ * @regulator: regulator source
+ *
+ * Returns the register map for the given regulator, or an ERR_PTR value
+ * if the regulator doesn't use regmap.
+ */
+struct regmap *regulator_get_regmap(struct regulator *regulator)
+{
+ struct regmap *map = regulator->rdev->regmap;
+
+ return map ? map : ERR_PTR(-EOPNOTSUPP);
+}
+
+/**
+ * regulator_get_hardware_vsel_register - get the HW voltage selector register
+ * @regulator: regulator source
+ * @vsel_reg: voltage selector register, output parameter
+ * @vsel_mask: mask for voltage selector bitfield, output parameter
+ *
+ * Returns the hardware register offset and bitmask used for setting the
+ * regulator voltage. This might be useful when configuring voltage-scaling
+ * hardware or firmware that can make I2C requests behind the kernel's back,
+ * for example.
+ *
+ * On success, the output parameters @vsel_reg and @vsel_mask are filled in
+ * and 0 is returned, otherwise a negative errno is returned.
+ */
+int regulator_get_hardware_vsel_register(struct regulator *regulator,
+ unsigned *vsel_reg,
+ unsigned *vsel_mask)
+{
+ struct regulator_dev *rdev = regulator->rdev;
+ struct regulator_ops *ops = rdev->desc->ops;
+
+ if (ops->set_voltage_sel != regulator_set_voltage_sel_regmap)
+ return -EOPNOTSUPP;
+
+ *vsel_reg = rdev->desc->vsel_reg;
+ *vsel_mask = rdev->desc->vsel_mask;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(regulator_get_hardware_vsel_register);
+
+/**
+ * regulator_list_hardware_vsel - get the HW-specific register value for a selector
+ * @regulator: regulator source
+ * @selector: identify voltage to list
+ *
+ * Converts the selector to a hardware-specific voltage selector that can be
+ * directly written to the regulator registers. The address of the voltage
+ * register can be determined by calling @regulator_get_hardware_vsel_register.
+ *
+ * On error a negative errno is returned.
+ */
+int regulator_list_hardware_vsel(struct regulator *regulator,
+ unsigned selector)
+{
+ struct regulator_dev *rdev = regulator->rdev;
+ struct regulator_ops *ops = rdev->desc->ops;
+
+ if (selector >= rdev->desc->n_voltages)
+ return -EINVAL;
+ if (ops->set_voltage_sel != regulator_set_voltage_sel_regmap)
+ return -EOPNOTSUPP;
+
+ return selector;
+}
+EXPORT_SYMBOL_GPL(regulator_list_hardware_vsel);
+
+/**
* regulator_get_linear_step - return the voltage step size between VSEL values
* @regulator: regulator source
*