drivers: pinctrl sleep and idle states in the core

If a device have sleep and idle states in addition to the
default state, look up these in the core and stash them in
the pinctrl state container.

Add accessor functions for pinctrl consumers to put the pins
into "default", "sleep" and "idle" states passing nothing but
the struct device * affected.

Solution suggested by Kevin Hilman, Mark Brown and Dmitry
Torokhov in response to a patch series from Hebbar
Gururaja.

Cc: Hebbar Gururaja <gururaja.hebbar@ti.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

4 files changed, 118 insertions, 0 deletions

diff --git a/drivers/base/pinctrl.c b/drivers/base/pinctrl.c
index 67a274e86727..5fb74b43848e 100644
--- a/drivers/base/pinctrl.c
+++ b/drivers/base/pinctrl.c
@@ -48,6 +48,25 @@ int pinctrl_bind_pins(struct device *dev)
 		goto cleanup_get;
 	}
 
+#ifdef CONFIG_PM
+	/*
+	 * If power management is enabled, we also look for the optional
+	 * sleep and idle pin states, with semantics as defined in
+	 * <linux/pinctrl/pinctrl-state.h>
+	 */
+	dev->pins->sleep_state = pinctrl_lookup_state(dev->pins->p,
+					PINCTRL_STATE_SLEEP);
+	if (IS_ERR(dev->pins->sleep_state))
+		/* Not supplying this state is perfectly legal */
+		dev_dbg(dev, "no sleep pinctrl state\n");
+
+	dev->pins->idle_state = pinctrl_lookup_state(dev->pins->p,
+					PINCTRL_STATE_IDLE);
+	if (IS_ERR(dev->pins->idle_state))
+		/* Not supplying this state is perfectly legal */
+		dev_dbg(dev, "no idle pinctrl state\n");
+#endif
+
 	return 0;
 
 	/*
diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c
index 1f9608bd237e..dca9208f5463 100644
--- a/drivers/pinctrl/core.c
+++ b/drivers/pinctrl/core.c
@@ -1196,6 +1196,67 @@ int pinctrl_force_default(struct pinctrl_dev *pctldev)
 }
 EXPORT_SYMBOL_GPL(pinctrl_force_default);
 
+#ifdef CONFIG_PM
+
+/**
+ * pinctrl_pm_select_default_state() - select default pinctrl state for PM
+ * @dev: device to select default state for
+ */
+int pinctrl_pm_select_default_state(struct device *dev)
+{
+	struct dev_pin_info *pins = dev->pins;
+	int ret;
+
+	if (!pins)
+		return 0;
+	if (IS_ERR(pins->default_state))
+		return 0; /* No default state */
+	ret = pinctrl_select_state(pins->p, pins->default_state);
+	if (ret)
+		dev_err(dev, "failed to activate default pinctrl state\n");
+	return ret;
+}
+
+/**
+ * pinctrl_pm_select_sleep_state() - select sleep pinctrl state for PM
+ * @dev: device to select sleep state for
+ */
+int pinctrl_pm_select_sleep_state(struct device *dev)
+{
+	struct dev_pin_info *pins = dev->pins;
+	int ret;
+
+	if (!pins)
+		return 0;
+	if (IS_ERR(pins->sleep_state))
+		return 0; /* No sleep state */
+	ret = pinctrl_select_state(pins->p, pins->sleep_state);
+	if (ret)
+		dev_err(dev, "failed to activate pinctrl sleep state\n");
+	return ret;
+}
+
+/**
+ * pinctrl_pm_select_idle_state() - select idle pinctrl state for PM
+ * @dev: device to select idle state for
+ */
+int pinctrl_pm_select_idle_state(struct device *dev)
+{
+	struct dev_pin_info *pins = dev->pins;
+	int ret;
+
+	if (!pins)
+		return 0;
+	if (IS_ERR(pins->idle_state))
+		return 0; /* No idle state */
+	ret = pinctrl_select_state(pins->p, pins->idle_state);
+	if (ret)
+		dev_err(dev, "failed to activate pinctrl idle state\n");
+	return ret;
+}
+
+#endif
+
 #ifdef CONFIG_DEBUG_FS
 
 static int pinctrl_pins_show(struct seq_file *s, void *what)
diff --git a/include/linux/pinctrl/consumer.h b/include/linux/pinctrl/consumer.h
index 4aad3cea69ae..0f32f10e347d 100644
--- a/include/linux/pinctrl/consumer.h
+++ b/include/linux/pinctrl/consumer.h
@@ -40,6 +40,25 @@ extern int pinctrl_select_state(struct pinctrl *p, struct pinctrl_state *s);
 extern struct pinctrl * __must_check devm_pinctrl_get(struct device *dev);
 extern void devm_pinctrl_put(struct pinctrl *p);
 
+#ifdef CONFIG_PM
+extern int pinctrl_pm_select_default_state(struct device *dev);
+extern int pinctrl_pm_select_sleep_state(struct device *dev);
+extern int pinctrl_pm_select_idle_state(struct device *dev);
+#else
+static inline int pinctrl_pm_select_default_state(struct device *dev)
+{
+	return 0;
+}
+static inline int pinctrl_pm_select_sleep_state(struct device *dev)
+{
+	return 0;
+}
+static inline int pinctrl_pm_select_idle_state(struct device *dev)
+{
+	return 0;
+}
+#endif
+
 #else /* !CONFIG_PINCTRL */
 
 static inline int pinctrl_request_gpio(unsigned gpio)
@@ -199,6 +218,21 @@ static inline int pin_config_group_set(const char *dev_name,
 	return 0;
 }
 
+static inline int pinctrl_pm_select_default_state(struct device *dev)
+{
+	return 0;
+}
+
+static inline int pinctrl_pm_select_sleep_state(struct device *dev)
+{
+	return 0;
+}
+
+static inline int pinctrl_pm_select_idle_state(struct device *dev)
+{
+	return 0;
+}
+
 #endif
 
 #endif /* __LINUX_PINCTRL_CONSUMER_H */
diff --git a/include/linux/pinctrl/devinfo.h b/include/linux/pinctrl/devinfo.h
index 6e5f8a985ea7..281cb91ddcf5 100644
--- a/include/linux/pinctrl/devinfo.h
+++ b/include/linux/pinctrl/devinfo.h
@@ -28,6 +28,10 @@
 struct dev_pin_info {
 	struct pinctrl *p;
 	struct pinctrl_state *default_state;
+#ifdef CONFIG_PM
+	struct pinctrl_state *sleep_state;
+	struct pinctrl_state *idle_state;
+#endif
 };
 
 extern int pinctrl_bind_pins(struct device *dev);