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authorTony Lindgren <tony@atomide.com>2017-01-12 01:13:34 +0300
committerLinus Walleij <linus.walleij@linaro.org>2017-01-13 18:25:17 +0300
commit950b0d91dc108f54bccca5a2f75bb46f2df63d29 (patch)
tree305daab89f93b16951c6a53efc9bb002eacdefc9 /drivers/pinctrl/core.c
parent56d9e4a76039afd504919cc5ec329fb0ce35812f (diff)
downloadlinux-950b0d91dc108f54bccca5a2f75bb46f2df63d29.tar.xz
pinctrl: core: Fix regression caused by delayed work for hogs
Commit df61b366af26 ("pinctrl: core: Use delayed work for hogs") caused a regression at least with sh-pfc that is also a GPIO controller as noted by Geert Uytterhoeven <geert@linux-m68k.org>. As the original pinctrl_register() has issues calling pin controller driver functions early before the controller has finished registering, we can't just revert commit df61b366af26. That would break the drivers using GENERIC_PINCTRL_GROUPS or GENERIC_PINMUX_FUNCTIONS. So let's fix the issue with the following steps as a single patch: 1. Revert the late_init parts of commit df61b366af26. The late_init clearly won't work and we have to just give up on fixing pinctrl_register() for GENERIC_PINCTRL_GROUPS and GENERIC_PINMUX_FUNCTIONS. 2. Split pinctrl_register() into two parts By splitting pinctrl_register() into pinctrl_init_controller() and pinctrl_create_and_start() we have better control over when it's safe to call pinctrl_create(). 3. Introduce a new pinctrl_register_and_init() function As suggested by Linus Walleij <linus.walleij@linaro.org>, we can just introduce a new function for the controllers that need pinctrl_create() called later. 4. Convert the four known problem cases to use new function Let's convert pinctrl-imx, pinctrl-single, sh-pfc and ti-iodelay to use the new function to fix the issues. The rest of the drivers can be converted later. Let's also update Documentation/pinctrl.txt accordingly because of the known issues with pinctrl_register(). Fixes: df61b366af26 ("pinctrl: core: Use delayed work for hogs") Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Gary Bisson <gary.bisson@boundarydevices.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/pinctrl/core.c')
-rw-r--r--drivers/pinctrl/core.c201
1 files changed, 139 insertions, 62 deletions
diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c
index 65c0ae0969dc..bc73a63163ee 100644
--- a/drivers/pinctrl/core.c
+++ b/drivers/pinctrl/core.c
@@ -1905,59 +1905,14 @@ static int pinctrl_check_ops(struct pinctrl_dev *pctldev)
}
/**
- * pinctrl_late_init() - finish pin controller device registration
- * @work: work struct
- */
-static void pinctrl_late_init(struct work_struct *work)
-{
- struct pinctrl_dev *pctldev;
-
- pctldev = container_of(work, struct pinctrl_dev, late_init.work);
-
- /*
- * If the pin controller does NOT have hogs, this will report an
- * error and we skip over this entire branch. This is why we can
- * call this function directly when we do not have hogs on the
- * device.
- */
- pctldev->p = create_pinctrl(pctldev->dev, pctldev);
- if (!IS_ERR(pctldev->p)) {
- kref_get(&pctldev->p->users);
- pctldev->hog_default =
- pinctrl_lookup_state(pctldev->p, PINCTRL_STATE_DEFAULT);
- if (IS_ERR(pctldev->hog_default)) {
- dev_dbg(pctldev->dev,
- "failed to lookup the default state\n");
- } else {
- if (pinctrl_select_state(pctldev->p,
- pctldev->hog_default))
- dev_err(pctldev->dev,
- "failed to select default state\n");
- }
-
- pctldev->hog_sleep =
- pinctrl_lookup_state(pctldev->p,
- PINCTRL_STATE_SLEEP);
- if (IS_ERR(pctldev->hog_sleep))
- dev_dbg(pctldev->dev,
- "failed to lookup the sleep state\n");
- }
-
- mutex_lock(&pinctrldev_list_mutex);
- list_add_tail(&pctldev->node, &pinctrldev_list);
- mutex_unlock(&pinctrldev_list_mutex);
-
- pinctrl_init_device_debugfs(pctldev);
-}
-
-/**
- * pinctrl_register() - register a pin controller device
+ * pinctrl_init_controller() - init a pin controller device
* @pctldesc: descriptor for this pin controller
* @dev: parent device for this pin controller
* @driver_data: private pin controller data for this pin controller
*/
-struct pinctrl_dev *pinctrl_register(struct pinctrl_desc *pctldesc,
- struct device *dev, void *driver_data)
+struct pinctrl_dev *pinctrl_init_controller(struct pinctrl_desc *pctldesc,
+ struct device *dev,
+ void *driver_data)
{
struct pinctrl_dev *pctldev;
int ret;
@@ -1983,7 +1938,6 @@ struct pinctrl_dev *pinctrl_register(struct pinctrl_desc *pctldesc,
INIT_RADIX_TREE(&pctldev->pin_function_tree, GFP_KERNEL);
#endif
INIT_LIST_HEAD(&pctldev->gpio_ranges);
- INIT_DELAYED_WORK(&pctldev->late_init, pinctrl_late_init);
pctldev->dev = dev;
mutex_init(&pctldev->mutex);
@@ -2018,17 +1972,6 @@ struct pinctrl_dev *pinctrl_register(struct pinctrl_desc *pctldesc,
goto out_err;
}
- /*
- * If the device has hogs we want the probe() function of the driver
- * to complete before we go in and hog them and add the pin controller
- * to the list of controllers. If it has no hogs, we can just complete
- * the registration immediately.
- */
- if (pinctrl_dt_has_hogs(pctldev))
- schedule_delayed_work(&pctldev->late_init, 0);
- else
- pinctrl_late_init(&pctldev->late_init.work);
-
return pctldev;
out_err:
@@ -2036,8 +1979,107 @@ out_err:
kfree(pctldev);
return ERR_PTR(ret);
}
+
+static int pinctrl_create_and_start(struct pinctrl_dev *pctldev)
+{
+ pctldev->p = create_pinctrl(pctldev->dev, pctldev);
+ if (!IS_ERR(pctldev->p)) {
+ kref_get(&pctldev->p->users);
+ pctldev->hog_default =
+ pinctrl_lookup_state(pctldev->p, PINCTRL_STATE_DEFAULT);
+ if (IS_ERR(pctldev->hog_default)) {
+ dev_dbg(pctldev->dev,
+ "failed to lookup the default state\n");
+ } else {
+ if (pinctrl_select_state(pctldev->p,
+ pctldev->hog_default))
+ dev_err(pctldev->dev,
+ "failed to select default state\n");
+ }
+
+ pctldev->hog_sleep =
+ pinctrl_lookup_state(pctldev->p,
+ PINCTRL_STATE_SLEEP);
+ if (IS_ERR(pctldev->hog_sleep))
+ dev_dbg(pctldev->dev,
+ "failed to lookup the sleep state\n");
+ }
+
+ mutex_lock(&pinctrldev_list_mutex);
+ list_add_tail(&pctldev->node, &pinctrldev_list);
+ mutex_unlock(&pinctrldev_list_mutex);
+
+ pinctrl_init_device_debugfs(pctldev);
+
+ return 0;
+}
+
+/**
+ * pinctrl_register() - register a pin controller device
+ * @pctldesc: descriptor for this pin controller
+ * @dev: parent device for this pin controller
+ * @driver_data: private pin controller data for this pin controller
+ *
+ * Note that pinctrl_register() is known to have problems as the pin
+ * controller driver functions are called before the driver has a
+ * struct pinctrl_dev handle. To avoid issues later on, please use the
+ * new pinctrl_register_and_init() below instead.
+ */
+struct pinctrl_dev *pinctrl_register(struct pinctrl_desc *pctldesc,
+ struct device *dev, void *driver_data)
+{
+ struct pinctrl_dev *pctldev;
+ int error;
+
+ pctldev = pinctrl_init_controller(pctldesc, dev, driver_data);
+ if (IS_ERR(pctldev))
+ return pctldev;
+
+ error = pinctrl_create_and_start(pctldev);
+ if (error) {
+ mutex_destroy(&pctldev->mutex);
+ kfree(pctldev);
+
+ return ERR_PTR(error);
+ }
+
+ return pctldev;
+
+}
EXPORT_SYMBOL_GPL(pinctrl_register);
+int pinctrl_register_and_init(struct pinctrl_desc *pctldesc,
+ struct device *dev, void *driver_data,
+ struct pinctrl_dev **pctldev)
+{
+ struct pinctrl_dev *p;
+ int error;
+
+ p = pinctrl_init_controller(pctldesc, dev, driver_data);
+ if (IS_ERR(p))
+ return PTR_ERR(p);
+
+ /*
+ * We have pinctrl_start() call functions in the pin controller
+ * driver with create_pinctrl() for at least dt_node_to_map(). So
+ * let's make sure pctldev is properly initialized for the
+ * pin controller driver before we do anything.
+ */
+ *pctldev = p;
+
+ error = pinctrl_create_and_start(p);
+ if (error) {
+ mutex_destroy(&p->mutex);
+ kfree(p);
+ *pctldev = NULL;
+
+ return error;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(pinctrl_register_and_init);
+
/**
* pinctrl_unregister() - unregister pinmux
* @pctldev: pin controller to unregister
@@ -2052,7 +2094,6 @@ void pinctrl_unregister(struct pinctrl_dev *pctldev)
if (pctldev == NULL)
return;
- cancel_delayed_work_sync(&pctldev->late_init);
mutex_lock(&pctldev->mutex);
pinctrl_remove_device_debugfs(pctldev);
mutex_unlock(&pctldev->mutex);
@@ -2134,6 +2175,42 @@ struct pinctrl_dev *devm_pinctrl_register(struct device *dev,
EXPORT_SYMBOL_GPL(devm_pinctrl_register);
/**
+ * devm_pinctrl_register_and_init() - Resource managed pinctrl register and init
+ * @dev: parent device for this pin controller
+ * @pctldesc: descriptor for this pin controller
+ * @driver_data: private pin controller data for this pin controller
+ *
+ * Returns an error pointer if pincontrol register failed. Otherwise
+ * it returns valid pinctrl handle.
+ *
+ * The pinctrl device will be automatically released when the device is unbound.
+ */
+int devm_pinctrl_register_and_init(struct device *dev,
+ struct pinctrl_desc *pctldesc,
+ void *driver_data,
+ struct pinctrl_dev **pctldev)
+{
+ struct pinctrl_dev **ptr;
+ int error;
+
+ ptr = devres_alloc(devm_pinctrl_dev_release, sizeof(*ptr), GFP_KERNEL);
+ if (!ptr)
+ return -ENOMEM;
+
+ error = pinctrl_register_and_init(pctldesc, dev, driver_data, pctldev);
+ if (error) {
+ devres_free(ptr);
+ return error;
+ }
+
+ *ptr = *pctldev;
+ devres_add(dev, ptr);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(devm_pinctrl_register_and_init);
+
+/**
* devm_pinctrl_unregister() - Resource managed version of pinctrl_unregister().
* @dev: device for which which resource was allocated
* @pctldev: the pinctrl device to unregister.