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Subject[PATCH 1/2] pinctrl: Allow a device to indicate when to force a state
Date
It may happen that a device needs to force applying a state, e.g:
because it only defines one state of pin states (default) but loses
power/register contents when entering low power modes. Add a
pinctrl_dev::flags bitmask to help describe future quirks and define
PINCTRL_FLG_FORCE_STATE as such a settable flag.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
drivers/pinctrl/core.c | 15 +++++++++++++++
drivers/pinctrl/core.h | 4 ++++
2 files changed, 19 insertions(+)

diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c
index 56fbe4c3e800..c450a97de88f 100644
--- a/drivers/pinctrl/core.c
+++ b/drivers/pinctrl/core.c
@@ -1197,11 +1197,26 @@ int pinctrl_select_state(struct pinctrl *p, struct pinctrl_state *state)
{
struct pinctrl_setting *setting, *setting2;
struct pinctrl_state *old_state = p->state;
+ bool force = false;
int ret;

if (p->state == state)
return 0;

+ if (p->state) {
+ list_for_each_entry(setting, &p->state->settings, node) {
+ if (setting->pctldev->flags & PINCTRL_FLG_FORCE_STATE)
+ force = true;
+ }
+ }
+
+ /* Some controllers may want to force this operation when they define
+ * only one set of functions and lose power state, e.g: pinctrl-single
+ * with its pinctrl-single,low-power-state-loss property.
+ */
+ if (p->state == state && !force)
+ return 0;
+
if (p->state) {
/*
* For each pinmux setting in the old state, forget SW's record
diff --git a/drivers/pinctrl/core.h b/drivers/pinctrl/core.h
index 7880c3adc450..5fbf4dd1fa76 100644
--- a/drivers/pinctrl/core.h
+++ b/drivers/pinctrl/core.h
@@ -39,6 +39,7 @@ struct pinctrl_gpio_range;
* @hog_sleep: sleep state for pins hogged by this device
* @mutex: mutex taken on each pin controller specific action
* @device_root: debugfs root for this device
+ * @flags: feature/quirk flags
*/
struct pinctrl_dev {
struct list_head node;
@@ -63,8 +64,11 @@ struct pinctrl_dev {
#ifdef CONFIG_DEBUG_FS
struct dentry *device_root;
#endif
+ unsigned long flags;
};

+#define PINCTRL_FLG_FORCE_STATE (1 << 0)
+
/**
* struct pinctrl - per-device pin control state holder
* @node: global list node
--
2.14.1
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