[PATCH 1/3] regulator: fixed: add possibility to enable by clock

[Philippe Schenker]

This commit adds the possibility to choose the compatible
"regulator-fixed-clock" in devicetree.

This is a special regulator-fixed that has to have a clock, from which
the regulator gets switched on and off.

Signed-off-by: Philippe Schenker <philippe.schen...@toradex.com>
---

 drivers/regulator/fixed.c | 86 +++++++++++++++++++++++++++++++++++++--
 1 file changed, 83 insertions(+), 3 deletions(-)

diff --git a/drivers/regulator/fixed.c b/drivers/regulator/fixed.c
index 999547dde99d..eadeca9a1a6c 100644
--- a/drivers/regulator/fixed.c
+++ b/drivers/regulator/fixed.c
@@ -23,14 +23,66 @@
 #include <linux/gpio/consumer.h>
 #include <linux/slab.h>
 #include <linux/of.h>
+#include <linux/of_device.h>
 #include <linux/regulator/of_regulator.h>
 #include <linux/regulator/machine.h>
+#include <linux/clk.h>
+
 
 struct fixed_voltage_data {
        struct regulator_desc desc;
        struct regulator_dev *dev;
+
+       struct clk *enable_clock;
+       unsigned int clk_enable_counter;
+};
+
+struct fixed_dev_type {
+       bool has_enable_clock;
+};
+
+static const struct fixed_dev_type fixed_voltage_data = {
+       .has_enable_clock = false,
 };
 
+static const struct fixed_dev_type fixed_clkenable_data = {
+       .has_enable_clock = true,
+};
+
+static int reg_clock_enable(struct regulator_dev *rdev)
+{
+       struct fixed_voltage_data *priv = rdev_get_drvdata(rdev);
+       int ret = 0;
+
+       ret = clk_prepare_enable(priv->enable_clock);
+       if (ret)
+               return ret;
+
+       priv->clk_enable_counter++;
+
+       return ret;
+}
+
+static int reg_clock_disable(struct regulator_dev *rdev)
+{
+       struct fixed_voltage_data *priv = rdev_get_drvdata(rdev);
+
+       clk_disable_unprepare(priv->enable_clock);
+       priv->clk_enable_counter--;
+
+       return 0;
+}
+
+static int reg_clock_is_enabled(struct regulator_dev *rdev)
+{
+       struct fixed_voltage_data *priv = rdev_get_drvdata(rdev);
+
+       if (priv->clk_enable_counter > 0)
+               return 1;
+
+       return 0;
+}
+
 
 /**
  * of_get_fixed_voltage_config - extract fixed_voltage_config structure info
@@ -84,10 +136,19 @@ of_get_fixed_voltage_config(struct device *dev,
 static struct regulator_ops fixed_voltage_ops = {
 };
 
+static struct regulator_ops fixed_voltage_clkenabled_ops = {
+       .enable = reg_clock_enable,
+       .disable = reg_clock_disable,
+       .is_enabled = reg_clock_is_enabled,
+};
+
 static int reg_fixed_voltage_probe(struct platform_device *pdev)
 {
+       struct device *dev = &pdev->dev;
        struct fixed_voltage_config *config;
        struct fixed_voltage_data *drvdata;
+       const struct fixed_dev_type *drvtype =
+               of_match_device(dev->driver->of_match_table, dev)->data;
        struct regulator_config cfg = { };
        enum gpiod_flags gflags;
        int ret;
@@ -118,7 +179,18 @@ static int reg_fixed_voltage_probe(struct platform_device 
*pdev)
        }
        drvdata->desc.type = REGULATOR_VOLTAGE;
        drvdata->desc.owner = THIS_MODULE;
-       drvdata->desc.ops = &fixed_voltage_ops;
+
+       if (drvtype->has_enable_clock) {
+               drvdata->desc.ops = &fixed_voltage_clkenabled_ops;
+
+               drvdata->enable_clock = devm_clk_get(dev, NULL);
+               if (IS_ERR(drvdata->enable_clock)) {
+                       dev_err(dev, "Cant get enable-clock from devicetree\n");
+                       return -ENOENT;
+               }
+       } else {
+               drvdata->desc.ops = &fixed_voltage_ops;
+       }
 
        drvdata->desc.enable_time = config->startup_delay;
 
@@ -191,8 +263,16 @@ static int reg_fixed_voltage_probe(struct platform_device 
*pdev)
 
 #if defined(CONFIG_OF)
 static const struct of_device_id fixed_of_match[] = {
-       { .compatible = "regulator-fixed", },
-       {},
+       {
+               .compatible = "regulator-fixed",
+               .data = &fixed_voltage_data,
+       },
+       {
+               .compatible = "regulator-fixed-clock",
+               .data = &fixed_clkenable_data,
+       },
+       {
+       },
 };
 MODULE_DEVICE_TABLE(of, fixed_of_match);
 #endif
-- 
2.23.0