From b043ed7ef0b358d7f32dc57c218f925fd2802aba Mon Sep 17 00:00:00 2001 From: Kent Gibson Date: Tue, 5 Nov 2019 10:04:28 +0800 Subject: [PATCH] gpiolib: move validation of line handle flags into helper function Move validation of line handle flags into helper function. This reduces the size and complexity of linehandle_create and allows the validation to be reused elsewhere. Signed-off-by: Kent Gibson Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpiolib.c | 93 +++++++++++++++++++++++------------------- 1 file changed, 51 insertions(+), 42 deletions(-) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index be159f56ff45..a9826627f347 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -428,6 +428,54 @@ struct linehandle_state { GPIOHANDLE_REQUEST_OPEN_DRAIN | \ GPIOHANDLE_REQUEST_OPEN_SOURCE) +static int linehandle_validate_flags(u32 flags) +{ + /* Return an error if an unknown flag is set */ + if (flags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) + return -EINVAL; + + /* + * Do not allow both INPUT & OUTPUT flags to be set as they are + * contradictory. + */ + if ((flags & GPIOHANDLE_REQUEST_INPUT) && + (flags & GPIOHANDLE_REQUEST_OUTPUT)) + return -EINVAL; + + /* + * Do not allow OPEN_SOURCE & OPEN_DRAIN flags in a single request. If + * the hardware actually supports enabling both at the same time the + * electrical result would be disastrous. + */ + if ((flags & GPIOHANDLE_REQUEST_OPEN_DRAIN) && + (flags & GPIOHANDLE_REQUEST_OPEN_SOURCE)) + return -EINVAL; + + /* OPEN_DRAIN and OPEN_SOURCE flags only make sense for output mode. */ + if (!(flags & GPIOHANDLE_REQUEST_OUTPUT) && + ((flags & GPIOHANDLE_REQUEST_OPEN_DRAIN) || + (flags & GPIOHANDLE_REQUEST_OPEN_SOURCE))) + return -EINVAL; + + /* Bias flags only allowed for input or output mode. */ + if (!((flags & GPIOHANDLE_REQUEST_INPUT) || + (flags & GPIOHANDLE_REQUEST_OUTPUT)) && + ((flags & GPIOHANDLE_REQUEST_BIAS_DISABLE) || + (flags & GPIOHANDLE_REQUEST_BIAS_PULL_UP) || + (flags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN))) + return -EINVAL; + + /* Only one bias flag can be set. */ + if (((flags & GPIOHANDLE_REQUEST_BIAS_DISABLE) && + (flags & (GPIOHANDLE_REQUEST_BIAS_PULL_DOWN | + GPIOHANDLE_REQUEST_BIAS_PULL_UP))) || + ((flags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN) && + (flags & GPIOHANDLE_REQUEST_BIAS_PULL_UP))) + return -EINVAL; + + return 0; +} + static long linehandle_ioctl(struct file *filep, unsigned int cmd, unsigned long arg) { @@ -529,48 +577,9 @@ static int linehandle_create(struct gpio_device *gdev, void __user *ip) lflags = handlereq.flags; - /* Return an error if an unknown flag is set */ - if (lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) - return -EINVAL; - - /* - * Do not allow both INPUT & OUTPUT flags to be set as they are - * contradictory. - */ - if ((lflags & GPIOHANDLE_REQUEST_INPUT) && - (lflags & GPIOHANDLE_REQUEST_OUTPUT)) - return -EINVAL; - - /* - * Do not allow OPEN_SOURCE & OPEN_DRAIN flags in a single request. If - * the hardware actually supports enabling both at the same time the - * electrical result would be disastrous. - */ - if ((lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) && - (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)) - return -EINVAL; - - /* OPEN_DRAIN and OPEN_SOURCE flags only make sense for output mode. */ - if (!(lflags & GPIOHANDLE_REQUEST_OUTPUT) && - ((lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) || - (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE))) - return -EINVAL; - - /* Bias flags only allowed for input or output mode. */ - if (!((lflags & GPIOHANDLE_REQUEST_INPUT) || - (lflags & GPIOHANDLE_REQUEST_OUTPUT)) && - ((lflags & GPIOHANDLE_REQUEST_BIAS_DISABLE) || - (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP) || - (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN))) - return -EINVAL; - - /* Only one bias flag can be set. */ - if (((lflags & GPIOHANDLE_REQUEST_BIAS_DISABLE) && - (lflags & (GPIOHANDLE_REQUEST_BIAS_PULL_DOWN | - GPIOHANDLE_REQUEST_BIAS_PULL_UP))) || - ((lflags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN) && - (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP))) - return -EINVAL; + ret = linehandle_validate_flags(lflags); + if (ret) + return ret; lh = kzalloc(sizeof(*lh), GFP_KERNEL); if (!lh) -- 2.45.2