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author | Tony Lindgren <tony@atomide.com> | 2017-01-11 14:13:34 -0800 |
---|---|---|
committer | Linus Walleij <linus.walleij@linaro.org> | 2017-01-13 16:25:17 +0100 |
commit | 950b0d91dc108f54bccca5a2f75bb46f2df63d29 (patch) | |
tree | 305daab89f93b16951c6a53efc9bb002eacdefc9 /drivers/pinctrl/core.c | |
parent | 56d9e4a76039afd504919cc5ec329fb0ce35812f (diff) | |
download | linux-stable-950b0d91dc108f54bccca5a2f75bb46f2df63d29.tar.gz linux-stable-950b0d91dc108f54bccca5a2f75bb46f2df63d29.tar.bz2 linux-stable-950b0d91dc108f54bccca5a2f75bb46f2df63d29.zip |
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.c | 201 |
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. |