[PATCH] pinctrl: Enforce device links

[Linus Walleij <linus.walleij@xxxxxxxxxx>]

Instead of opt-in device links, enforce it across the board.
Everyone probably needs this anyway, lest runtime[_pm] suspend
order will be haphazard.

Cc: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Cc: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
---
As there is no progress on opting in drivers for this we can just
enforce it.

I am a bit concerned that with every pin control state change the
link reference count will just go up, but does it really matter?
---
 drivers/pinctrl/core.c                | 25 ++++++++++++++-----------
 drivers/pinctrl/pinctrl-stmfx.c       |  1 -
 drivers/pinctrl/stm32/pinctrl-stm32.c |  1 -
 include/linux/pinctrl/pinctrl.h       |  5 -----
 4 files changed, 14 insertions(+), 18 deletions(-)

diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c
index 2bbd8ee93507..1d2cdeebb316 100644
--- a/drivers/pinctrl/core.c
+++ b/drivers/pinctrl/core.c
@@ -1220,15 +1220,6 @@ struct pinctrl_state *pinctrl_lookup_state(struct pinctrl *p,
 }
 EXPORT_SYMBOL_GPL(pinctrl_lookup_state);
 
-static void pinctrl_link_add(struct pinctrl_dev *pctldev,
-			     struct device *consumer)
-{
-	if (pctldev->desc->link_consumers)
-		device_link_add(consumer, pctldev->dev,
-				DL_FLAG_PM_RUNTIME |
-				DL_FLAG_AUTOREMOVE_CONSUMER);
-}
-
 /**
  * pinctrl_commit_state() - select/activate/program a pinctrl state to HW
  * @p: the pinctrl handle for the device that requests configuration
@@ -1276,8 +1267,20 @@ static int pinctrl_commit_state(struct pinctrl *p, struct pinctrl_state *state)
 		}
 
 		/* Do not link hogs (circular dependency) */
-		if (p != setting->pctldev->p)
-			pinctrl_link_add(setting->pctldev, p->dev);
+		if (p != setting->pctldev->p) {
+			/*
+			 * Create a device link to the consumer such that
+			 * it will enforce that runtime PM suspend/resume
+			 * is done first on consumers before we get to
+			 * the pin controller itself. As some devices get
+			 * their pin control state even before probe() it is
+			 * important to use DL_FLAG_AUTOREMOVE_CONSUMER.
+			 */
+			device_link_add(p->dev,
+					setting->pctldev->dev,
+					DL_FLAG_PM_RUNTIME |
+					DL_FLAG_AUTOREMOVE_CONSUMER);
+		}
 	}
 
 	p->state = state;
diff --git a/drivers/pinctrl/pinctrl-stmfx.c b/drivers/pinctrl/pinctrl-stmfx.c
index 16723797fa7c..4306b8444188 100644
--- a/drivers/pinctrl/pinctrl-stmfx.c
+++ b/drivers/pinctrl/pinctrl-stmfx.c
@@ -638,7 +638,6 @@ static int stmfx_pinctrl_probe(struct platform_device *pdev)
 	pctl->pctl_desc.pins = stmfx_pins;
 	pctl->pctl_desc.npins = ARRAY_SIZE(stmfx_pins);
 	pctl->pctl_desc.owner = THIS_MODULE;
-	pctl->pctl_desc.link_consumers = true;
 
 	ret = devm_pinctrl_register_and_init(pctl->dev, &pctl->pctl_desc,
 					     pctl, &pctl->pctl_dev);
diff --git a/drivers/pinctrl/stm32/pinctrl-stm32.c b/drivers/pinctrl/stm32/pinctrl-stm32.c
index 2d5e0435af0a..ec59a58600ce 100644
--- a/drivers/pinctrl/stm32/pinctrl-stm32.c
+++ b/drivers/pinctrl/stm32/pinctrl-stm32.c
@@ -1439,7 +1439,6 @@ int stm32_pctl_probe(struct platform_device *pdev)
 	pctl->pctl_desc.owner = THIS_MODULE;
 	pctl->pctl_desc.pins = pins;
 	pctl->pctl_desc.npins = pctl->npins;
-	pctl->pctl_desc.link_consumers = true;
 	pctl->pctl_desc.confops = &stm32_pconf_ops;
 	pctl->pctl_desc.pctlops = &stm32_pctrl_ops;
 	pctl->pctl_desc.pmxops = &stm32_pmx_ops;
diff --git a/include/linux/pinctrl/pinctrl.h b/include/linux/pinctrl/pinctrl.h
index 7ce23450a1cb..c6159f041f4e 100644
--- a/include/linux/pinctrl/pinctrl.h
+++ b/include/linux/pinctrl/pinctrl.h
@@ -122,10 +122,6 @@ struct pinctrl_ops {
  *	the hardware description
  * @custom_conf_items: Information how to print @params in debugfs, must be
  *	the same size as the @custom_params, i.e. @num_custom_params
- * @link_consumers: If true create a device link between pinctrl and its
- *	consumers (i.e. the devices requesting pin control states). This is
- *	sometimes necessary to ascertain the right suspend/resume order for
- *	example.
  */
 struct pinctrl_desc {
 	const char *name;
@@ -140,7 +136,6 @@ struct pinctrl_desc {
 	const struct pinconf_generic_params *custom_params;
 	const struct pin_config_item *custom_conf_items;
 #endif
-	bool link_consumers;
 };
 
 /* External interface to pin controller */
-- 
2.23.0