linux-kernel - [PATCH 2/4] pinctrl: Allow pinctrl to have multiple active states

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Message-ID: <20130718151507.30990.67174.stgit@localhost>
Date:	Thu, 18 Jul 2013 08:15:07 -0700
From:	Tony Lindgren <tony@...mide.com>
To:	linus.walleij@...aro.org
Cc:	Grygorii Strashko <grygorii.strashko@...com>,
	Stephen Warren <swarren@...dotorg.org>,
	linux-kernel@...r.kernel.org, Felipe Balbi <balbi@...com>,
	linux-omap@...r.kernel.org, linux-arm-kernel@...ts.infradead.org
Subject: [PATCH 2/4] pinctrl: Allow pinctrl to have multiple active states

It's quite common that we need to dynamically change some pins for a
device for runtime PM, or toggle a pin between rx and tx. Changing all
the pins for a device is not efficient way of doing it.

So let's allow setting up multiple active states for pinctrl. Currently
we only need PINCTRL_STATIC and PINCTRL_DYNAMIC, where PINCTRL_STATIC
covers the current default pins, and PINCTRL_DYNAMIC holds the dynamic
pins that need to be toggled.

Cc: Felipe Balbi <balbi@...com>
Cc: Grygorii Strashko <grygorii.strashko@...com>
Cc: Stephen Warren <swarren@...dotorg.org>
Signed-off-by: Tony Lindgren <tony@...mide.com>
---
 drivers/pinctrl/core.c |   18 ++++++++++--------
 drivers/pinctrl/core.h |   10 ++++++++--
 2 files changed, 18 insertions(+), 10 deletions(-)

diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c
index a97b717..c9b709b 100644
--- a/drivers/pinctrl/core.c
+++ b/drivers/pinctrl/core.c
@@ -885,7 +885,8 @@ static void pinctrl_free(struct pinctrl *p, bool inlist)
 	mutex_lock(&pinctrl_list_mutex);
 	list_for_each_entry_safe(state, n1, &p->states, node) {
 		list_for_each_entry_safe(setting, n2, &state->settings, node) {
-			pinctrl_free_setting(state == p->state, setting);
+			pinctrl_free_setting(state == p->state[PINCTRL_STATIC],
+					     setting);
 			list_del(&setting->node);
 			kfree(setting);
 		}
@@ -955,13 +956,13 @@ EXPORT_SYMBOL_GPL(pinctrl_lookup_state);
 int pinctrl_select_state(struct pinctrl *p, struct pinctrl_state *state)
 {
 	struct pinctrl_setting *setting, *setting2;
-	struct pinctrl_state *old_state = p->state;
+	struct pinctrl_state *old_state = p->state[PINCTRL_STATIC];
 	int ret;
 
-	if (p->state == state)
+	if (old_state == state)
 		return 0;
 
-	if (p->state) {
+	if (old_state) {
 		/*
 		 * The set of groups with a mux configuration in the old state
 		 * may not be identical to the set of groups with a mux setting
@@ -971,7 +972,7 @@ int pinctrl_select_state(struct pinctrl *p, struct pinctrl_state *state)
 		 * but not in the new state, this code puts that group into a
 		 * safe/disabled state.
 		 */
-		list_for_each_entry(setting, &p->state->settings, node) {
+		list_for_each_entry(setting, &old_state->settings, node) {
 			bool found = false;
 			if (setting->type != PIN_MAP_TYPE_MUX_GROUP)
 				continue;
@@ -989,7 +990,7 @@ int pinctrl_select_state(struct pinctrl *p, struct pinctrl_state *state)
 		}
 	}
 
-	p->state = NULL;
+	p->state[PINCTRL_STATIC] = NULL;
 
 	/* Apply all the settings for the new state */
 	list_for_each_entry(setting, &state->settings, node) {
@@ -1011,7 +1012,7 @@ int pinctrl_select_state(struct pinctrl *p, struct pinctrl_state *state)
 		}
 	}
 
-	p->state = state;
+	p->state[PINCTRL_STATIC] = state;
 
 	return 0;
 
@@ -1492,7 +1493,8 @@ static int pinctrl_show(struct seq_file *s, void *what)
 	list_for_each_entry(p, &pinctrl_list, node) {
 		seq_printf(s, "device: %s current state: %s\n",
 			   dev_name(p->dev),
-			   p->state ? p->state->name : "none");
+			   p->state[PINCTRL_STATIC] ?
+			   p->state[PINCTRL_STATIC]->name : "none");
 
 		list_for_each_entry(state, &p->states, node) {
 			seq_printf(s, "  state: %s\n", state->name);
diff --git a/drivers/pinctrl/core.h b/drivers/pinctrl/core.h
index 75476b3..ac5a269 100644
--- a/drivers/pinctrl/core.h
+++ b/drivers/pinctrl/core.h
@@ -53,12 +53,18 @@ struct pinctrl_dev {
 #endif
 };
 
+enum pinctrl_states {
+	PINCTRL_STATIC,
+	PINCTRL_DYNAMIC,
+	PINCTRL_NR_STATES,
+};
+
 /**
  * struct pinctrl - per-device pin control state holder
  * @node: global list node
  * @dev: the device using this pin control handle
  * @states: a list of states for this device
- * @state: the current state
+ * @state: the current state(s)
  * @dt_maps: the mapping table chunks dynamically parsed from device tree for
  *	this device, if any
  * @users: reference count
@@ -67,7 +73,7 @@ struct pinctrl {
 	struct list_head node;
 	struct device *dev;
 	struct list_head states;
-	struct pinctrl_state *state;
+	struct pinctrl_state *state[PINCTRL_NR_STATES];
 	struct list_head dt_maps;
 	struct kref users;
 };

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