tree 791ed72218bdf8b543e329dae759601c4f534443
parent 16de7dede23b2cf0c6a17b23e3317ef9b0c9ac9c
author Christian Lamparter <chunkeey@gmail.com> 1526936257 +0200
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1550654455 +0100

pinctrl: msm: fix gpio-hog related boot issues

commit a86caa9ba5d70696ceb35d1d39caa20d8b641387 upstream.

Sven Eckelmann reported an issue with the current IPQ4019 pinctrl.
Setting up any gpio-hog in the device-tree for his device would
"kill the bootup completely":

| [    0.477838] msm_serial 78af000.serial: could not find pctldev for node /soc/pinctrl@1000000/serial_pinmux, deferring probe
| [    0.499828] spi_qup 78b5000.spi: could not find pctldev for node /soc/pinctrl@1000000/spi_0_pinmux, deferring probe
| [    1.298883] requesting hog GPIO enable USB2 power (chip 1000000.pinctrl, offset 58) failed, -517
| [    1.299609] gpiochip_add_data: GPIOs 0..99 (1000000.pinctrl) failed to register
| [    1.308589] ipq4019-pinctrl 1000000.pinctrl: Failed register gpiochip
| [    1.316586] msm_serial 78af000.serial: could not find pctldev for node /soc/pinctrl@1000000/serial_pinmux, deferring probe
| [    1.322415] spi_qup 78b5000.spi: could not find pctldev for node /soc/pinctrl@1000000/spi_0_pinmux, deferri

This was also verified on a RT-AC58U (IPQ4018) which would
no longer boot, if a gpio-hog was specified. (Tried forcing
the USB LED PIN (GPIO0) to high.).

The problem is that Pinctrl+GPIO registration is currently
peformed in the following order in pinctrl-msm.c:
	1. pinctrl_register()
	2. gpiochip_add()
	3. gpiochip_add_pin_range()

The actual error code -517 == -EPROBE_DEFER is coming from
pinctrl_get_device_gpio_range(), which is called through:
        gpiochip_add
            of_gpiochip_add
                of_gpiochip_scan_gpios
                    gpiod_hog
                        gpiochip_request_own_desc
                            __gpiod_request
                                chip->request
                                    gpiochip_generic_request
                                       pinctrl_gpio_request
                                          pinctrl_get_device_gpio_range

pinctrl_get_device_gpio_range() is unable to find any valid
pin ranges, since nothing has been added to the pinctrldev_list yet.
so the range can't be found, and the operation fails with -EPROBE_DEFER.

This patch fixes the issue by adding the "gpio-ranges" property to
the pinctrl device node of all upstream Qcom SoC. The pin ranges are
then added by the gpio core.

In order to remain compatible with older, existing DTs (and ACPI)
a check for the "gpio-ranges" property has been added to
msm_gpio_init(). This prevents the driver of adding the same entry
to the pinctrldev_list twice.

Reported-by: Sven Eckelmann <sven.eckelmann@openmesh.com>
Tested-by: Sven Eckelmann <sven.eckelmann@openmesh.com> [ipq4019]
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>