pinctrl: samsung: Register pinctrl before GPIO
Subsystems (4)
PATCH v3 1/2 pinctrl: samsung: Register pinctrl before GPIO
If we request a GPIO hog, then gpiochip_add_data will attempt to request some of its own GPIOs. The driver also uses gpiochip_generic_request which means that for any GPIO request to succeed the pinctrl needs to be registered. Currently however the driver registers the GPIO and then the pinctrl meaning all GPIO hog requests will fail, which then in turn causes the whole driver to fail probe.
Fix this up by ensuring we register the pinctrl first. This does require us to manually set the GPIO base for the pinctrl. Fortunately the driver already assigns a fixed GPIO base, in samsung_gpiolib_register, and uses the same calculation it does for the pin_base. Meaning the two will always be the same and allowing us to reuse the pinbase and avoid the issue.
Although currently there are no users of GPIO hogs in mainline there are plenty of Samsung based boards that are widely used for development purposes of other hardware. Indeed we hit this issue whilst attaching some additional hardware to an Arndale system.
---
Changes since v2:
- Squash in fix to set the GPIO base on the pin_bank.
drivers/pinctrl/samsung/pinctrl-samsung.c | 36 +++++++++++++++---------------- 1 file changed, 18 insertions(+), 18 deletions(-)
drivers/pinctrl/samsung/pinctrl-samsung.c +18 -18
@@ -884,7 +884,7 @@ static int samsung_pinctrl_register(struct platform_device *pdev, pin_bank->grange.id = bank; pin_bank->grange.pin_base = drvdata->pin_base + pin_bank->pin_base; - pin_bank->grange.base = pin_bank->gpio_chip.base; + pin_bank->grange.base = pin_bank->grange.pin_base; pin_bank->grange.npins = pin_bank->gpio_chip.ngpio; pin_bank->grange.gc = &pin_bank->gpio_chip;pinctrl_add_gpio_range (drvdata->pctl_dev, &pin_bank->grange);
@@ -893,6 +893,19 @@ static int samsung_pinctrl_register(struct platform_device *pdev,return 0 ; } +/* unregister the pinctrl interface with the pinctrl subsystem */ +static int samsung_pinctrl_unregister (struct platform_device *pdev, +struct samsung_pinctrl_drv_data *drvdata) +{ +struct samsung_pin_bank *bank = drvdata->pin_banks; +int i; + +for (i =0 ; i < drvdata->nr_banks; ++i, ++bank) +pinctrl_remove_gpio_range (drvdata->pctl_dev, &bank->grange); + +return 0 ; +} +static const struct gpio_chip samsung_gpiolib_chip = { .request = gpiochip_generic_request, .free = gpiochip_generic_free,
@@ -917,7 +930,7 @@ static int samsung_gpiolib_register(struct platform_device *pdev, bank->gpio_chip = samsung_gpiolib_chip; gc = &bank->gpio_chip; - gc->base = drvdata->pin_base + bank->pin_base; + gc->base = bank->grange.base; gc->ngpio = bank->nr_pins; gc->parent = &pdev->dev; gc->of_node = bank->of_node;
@@ -939,19 +952,6 @@ static int samsung_gpiolib_register(struct platform_device *pdev,return ret; } -/* unregister the gpiolib interface with the gpiolib subsystem */ -static int samsung_gpiolib_unregister (struct platform_device *pdev, -struct samsung_pinctrl_drv_data *drvdata) -{ -struct samsung_pin_bank *bank = drvdata->pin_banks; -int i; - -for (i =0 ; i < drvdata->nr_banks; ++i, ++bank) -gpiochip_remove (&bank->gpio_chip); - -return 0 ; -} -/* retrieve the soc specific data */ static const struct samsung_pin_ctrl * samsung_pinctrl_get_soc_data(struct samsung_pinctrl_drv_data *d,
@@ -1062,13 +1062,13 @@ static int samsung_pinctrl_probe(struct platform_device *pdev)return PTR_ERR (drvdata->retention_ctrl); } - ret =samsung_gpiolib_register (pdev, drvdata); + ret =samsung_pinctrl_register (pdev, drvdata);if (ret)return ret; - ret =samsung_pinctrl_register (pdev, drvdata); + ret =samsung_gpiolib_register (pdev, drvdata);if (ret) { -samsung_gpiolib_unregister (pdev, drvdata); +samsung_pinctrl_unregister (pdev, drvdata);return ret; }
Signature · 1 line
2.1.4
PATCH v3 2/2 pinctrl: samsung: Use devres version of gpiochip_add_data
Use devm_gpiochip_add_data to simplify the error path in samsung_gpiolib_register.
---
No changes since v2.
drivers/pinctrl/samsung/pinctrl-samsung.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-)
drivers/pinctrl/samsung/pinctrl-samsung.c +2 -7
@@ -936,20 +936,15 @@ static int samsung_gpiolib_register(struct platform_device *pdev, gc->of_node = bank->of_node; gc->label = bank->name; - ret =gpiochip_add_data (gc, bank); + ret =devm_gpiochip_add_data (&pdev->dev, gc, bank);if (ret) {dev_err (&pdev->dev,"failed to register gpio_chip %s, error code: %d\n" , gc->label, ret); - goto fail; +return ret; } }return 0 ; - -fail: -for (--i, --bank; i >=0 ; --i, --bank) -gpiochip_remove (&bank->gpio_chip); -return ret; }/* retrieve the soc specific data */
Signature · 1 line
2.1.4
Re: [PATCH v3 2/2] pinctrl: samsung: Use devres version of gpiochip_add_data
Quoted 12 lines · Charles Keepax
Use
devm_gpiochip_add_datato simplify the error path insamsung_gpiolib_register.Signed-off-by Charles Keepax <[email protected]>Reviewed-by Krzysztof Kozlowski <[email protected]>---
No changes since v2.
drivers/pinctrl/samsung/pinctrl-samsung.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-)
Thanks, applied.
Best regards,
Krzysztof
Quoted 20 lines · Charles Keepax
If we request a GPIO hog, then
gpiochip_add_datawill attempt to request some of its own GPIOs. The driver also usesgpiochip_generic_requestwhich means that for any GPIO request to succeed the pinctrl needs to be registered. Currently however the driver registers the GPIO and then the pinctrl meaning all GPIO hog requests will fail, which then in turn causes the whole driver to fail probe.Fix this up by ensuring we register the pinctrl first. This does require us to manually set the GPIO base for the pinctrl. Fortunately the driver already assigns a fixed GPIO base, in
samsung_gpiolib_register, and uses the same calculation it does for thepin_base. Meaning the two will always be the same and allowing us to reuse the pinbase and avoid the issue.Although currently there are no users of GPIO hogs in mainline there are plenty of Samsung based boards that are widely used for development purposes of other hardware. Indeed we hit this issue whilst attaching some additional hardware to an Arndale system.
Quoted 9 lines
Signed-off-by Charles Keepax <[email protected]>---
Changes since v2:
- Squash in fix to set the GPIO base on thepin_bank.drivers/pinctrl/samsung/pinctrl-samsung.c | 36 +++++++++++++++---------------- 1 file changed, 18 insertions(+), 18 deletions(-)
Thanks, applied.
Best regards,
Krzysztof