Commit 47a3734b authored May 14, 2020 by Rodrigo Alencar Committed by Bartosz Golaszewski May 22, 2020

gpio: max730x: bring gpiochip_add_data after port config



gpiochip_add_data being called before might cause premature calls of
the gpiochip operations before the port_config values are initialized,
which would possibily write zeros to port configuration registers,
an operation not allowed. For example, if there are gpio-hog nodes
in a device-tree, the sequence of function calls are performed

gpiochip_add_data
of_gpiochip_add
of_gpiochip_scan_gpios
of_gpiochip_add_hog
gpiod_hog
gpiochip_request_own_desc
gpiod_configure_flags
gpiod_direction_output/gpiod_direction_input

which would call later the gpiochip operation direction_output or
direction_input prior the port_config[] initialization.

Moreover, gpiochip_get_data is replaced by the container_of macro
inside the gpiochip operations, which would allow the calling of
max7301_direction_input prior to gpiochip_add_data

Signed-off-by: Rodrigo Alencar <455.rodrigo.alencar@gmail.com>
[Bartosz: tweaked the commit message]
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

parent 3831c051

drivers/gpio/gpio-max730x.c

+5 −7

Original line number	Diff line number	Diff line
		@@ -47,7 +47,7 @@

		static int max7301_direction_input(struct gpio_chip *chip, unsigned offset)
		{
		struct max7301 *ts = gpiochip_get_data(chip);
		struct max7301 *ts = container_of(chip, struct max7301, chip);
		u8 *config;
		u8 offset_bits, pin_config;
		int ret;
		@@ -89,7 +89,7 @@ static int __max7301_set(struct max7301 *ts, unsigned offset, int value)
		static int max7301_direction_output(struct gpio_chip *chip, unsigned offset,
		int value)
		{
		struct max7301 *ts = gpiochip_get_data(chip);
		struct max7301 *ts = container_of(chip, struct max7301, chip);
		u8 *config;
		u8 offset_bits;
		int ret;
		@@ -189,10 +189,6 @@ int __max730x_probe(struct max7301 *ts)
		ts->chip.parent = dev;
		ts->chip.owner = THIS_MODULE;

		ret = gpiochip_add_data(&ts->chip, ts);
		if (ret)
		goto exit_destroy;

		/*
		* initialize pullups according to platform data and cache the
		* register values for later use.
		@@ -214,6 +210,8 @@ int __max730x_probe(struct max7301 *ts)
		}
		}

		ret = gpiochip_add_data(&ts->chip, ts);
		if (!ret)
		return ret;

		exit_destroy:

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