IKXCLOCK-166 misc: c55_ctrl: add dynamic pinmux and regulator

Some pins that are shared between AP and C55 can be driven by either
C55 or AP, but not both. Add mechanism to control the pin mux when
AP doesn't need those pins. Also, add dynamic regulator control when
c55 is not enabled.

Change-Id: I31d9ee40e0e8946620c66d716a8d9cb0bbdbbe16
Signed-off-by: Mohsan Habibi <mohsan@motorola.com>

1 files changed, 116 insertions, 11 deletions

diff --git a/drivers/misc/c55_ctrl.c b/drivers/misc/c55_ctrl.c
index 3c116987e3d..9dc6f55a305 100644
--- a/drivers/misc/c55_ctrl.c
+++ b/drivers/misc/c55_ctrl.c
@@ -24,10 +24,26 @@
 #include <linux/of_gpio.h>
 #include <linux/clk.h>
 
+enum {
+	C55_OFF,
+	C55_ON,
+	C55_MODE_MAX
+};
+
 struct c55_ctrl_data {
 	int int_gpio;
 	struct wake_lock wake_lock;
-	struct regulator *reg;
+	struct regulator *reg_vddc;
+	struct regulator *reg_vddldo;
+	struct pinctrl *pctrl;
+	struct pinctrl_state *states[C55_MODE_MAX];
+	int c55_mode;
+	struct mutex ctrl_mutex;	/* mutex to handle critical area */
+};
+
+const char *c55_pin_state_labels[C55_MODE_MAX] = {
+	"off",
+	"on"
 };
 
 #define NUM_GPIOS 3
@@ -117,6 +133,81 @@ static int c55_ctrl_gpio_setup(struct c55_ctrl_data *cdata, struct device *dev)
 	return 0;
 }
 
+static ssize_t c55_ctrl_enable(struct device *dev,
+	struct device_attribute *attr, const char *buf, size_t count)
+{
+	struct c55_ctrl_data *cdata = dev_get_drvdata(dev);
+	int mode;
+
+	if (kstrtoint(buf, 10, &mode) < 0)
+		return -EINVAL;
+
+	if (mode >= C55_MODE_MAX) {
+		dev_err(dev, "%s: Invalid mode %d\n", __func__, mode);
+		return -EINVAL;
+	}
+
+	if (mode == cdata->c55_mode)
+		return count;
+
+	mutex_lock(&cdata->ctrl_mutex);
+
+	if (mode == C55_ON) {
+		pinctrl_select_state(cdata->pctrl, cdata->states[mode]);
+		if (cdata->reg_vddc && regulator_enable(cdata->reg_vddc))
+			dev_err(dev, "regulator_enable failed for vddc\n");
+		if (cdata->reg_vddldo && regulator_enable(cdata->reg_vddldo))
+			dev_err(dev, "regulator_enable failed for vddldo\n");
+	} else {
+		if (cdata->reg_vddldo)
+			regulator_disable(cdata->reg_vddldo);
+		if (cdata->reg_vddc)
+			regulator_disable(cdata->reg_vddc);
+		pinctrl_select_state(cdata->pctrl, cdata->states[mode]);
+	}
+
+	cdata->c55_mode = mode;
+
+	mutex_unlock(&cdata->ctrl_mutex);
+
+	dev_info(dev, "%s: power = %d\n", __func__, mode);
+
+	return count;
+}
+
+static DEVICE_ATTR(enable, S_IWUSR, NULL, c55_ctrl_enable);
+
+static int c55_ctrl_pin_setup(struct device *dev, struct c55_ctrl_data *cdata)
+{
+	int i, ret = 0;
+
+	cdata->pctrl = devm_pinctrl_get(dev);
+	if (IS_ERR(cdata->pctrl)) {
+		ret = PTR_ERR(cdata->pctrl);
+		dev_dbg(dev, "no pinctrl handle\n");
+	}
+
+	for (i = 0; !ret && (i < C55_MODE_MAX); i++) {
+		cdata->states[i] = pinctrl_lookup_state(cdata->pctrl,
+					c55_pin_state_labels[i]);
+		if (IS_ERR(cdata->states[i])) {
+			ret = PTR_ERR(cdata->states[i]);
+			dev_dbg(dev, "no %s pinctrl state\n",
+				c55_pin_state_labels[i]);
+		}
+	}
+
+	if (!ret) {
+		ret = pinctrl_select_state(cdata->pctrl,
+					cdata->states[C55_OFF]);
+		if (ret)
+			dev_dbg(dev, "failed to activate %s pinctrl state\n",
+				c55_pin_state_labels[C55_OFF]);
+	}
+
+	return ret;
+}
+
 static int  c55_ctrl_probe(struct platform_device *pdev)
 {
 	struct c55_ctrl_data *cdata;
@@ -132,6 +223,16 @@ static int  c55_ctrl_probe(struct platform_device *pdev)
 		dev_err(&pdev->dev, "%s: devm_kzalloc failed.\n", __func__);
 		return -ENOMEM;
 	}
+
+	mutex_init(&cdata->ctrl_mutex);
+
+	ret = c55_ctrl_pin_setup(&pdev->dev, cdata);
+	if (ret) {
+		dev_err(&pdev->dev, "%s: c55_ctrl_pin_setup failed.\n",
+			__func__);
+		return ret;
+	}
+
 	cdata->int_gpio = -1;
 	ret = c55_ctrl_gpio_setup(cdata, &pdev->dev);
 
@@ -140,14 +241,20 @@ static int  c55_ctrl_probe(struct platform_device *pdev)
 		return ret;
 	}
 
-	cdata->reg = regulator_get(&pdev->dev, "c55-ctrl");
-	if (IS_ERR(cdata->reg)) {
-		return PTR_ERR(cdata->reg);
-	}
-	ret = regulator_enable(cdata->reg);
+	cdata->reg_vddc = devm_regulator_get(&pdev->dev, "vddc");
+	if (IS_ERR(cdata->reg_vddc))
+		cdata->reg_vddc = NULL;
+
+	cdata->reg_vddldo = devm_regulator_get(&pdev->dev, "vddldo");
+	if (IS_ERR(cdata->reg_vddldo))
+		cdata->reg_vddldo = NULL;
+
+	cdata->c55_mode = C55_OFF;
+
+	ret = device_create_file(&pdev->dev, &dev_attr_enable);
 	if (ret) {
-		dev_err(&pdev->dev, "%s: c55_ctrl regulator_enable failed.\n", __func__);
-		regulator_put(cdata->reg);
+		dev_err(&pdev->dev, "%s: c55_ctrl creating set_mode failed.\n",
+			__func__);
 		return ret;
 	}
 
@@ -159,9 +266,7 @@ static int  c55_ctrl_probe(struct platform_device *pdev)
 
 static int  c55_ctrl_remove(struct platform_device *pdev)
 {
-	struct c55_ctrl_data *cdata = platform_get_drvdata(pdev);
-
-	regulator_put(cdata->reg);
+	device_remove_file(&pdev->dev, &dev_attr_enable);
 	return 0;
 }