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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>
This commit is contained in:
Rodrigo Alencar 2020-05-14 10:00:12 -03:00 committed by Bartosz Golaszewski
parent 3831c051df
commit 47a3734b03
1 changed files with 5 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
drivers/gpio/gpio-max730x.c
View File

@ -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.
@ -214,7 +210,9 @@ int __max730x_probe(struct max7301 *ts)
}
}
return ret;
ret = gpiochip_add_data(&ts->chip, ts);
if (!ret)
return ret;
exit_destroy:
mutex_destroy(&ts->lock);