diff options
| -rw-r--r-- | drivers/gpio/gpiolib.c | 69 | ||||
| -rw-r--r-- | include/uapi/linux/gpio.h | 18 |
2 files changed, 87 insertions, 0 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index a9826627f347..dba5f08f308c 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -476,6 +476,73 @@ static int linehandle_validate_flags(u32 flags) return 0; } +static void linehandle_configure_flag(unsigned long *flagsp, + u32 bit, bool active) +{ + if (active) + set_bit(bit, flagsp); + else + clear_bit(bit, flagsp); +} + +static long linehandle_set_config(struct linehandle_state *lh, + void __user *ip) +{ + struct gpiohandle_config gcnf; + struct gpio_desc *desc; + int i, ret; + u32 lflags; + unsigned long *flagsp; + + if (copy_from_user(&gcnf, ip, sizeof(gcnf))) + return -EFAULT; + + lflags = gcnf.flags; + ret = linehandle_validate_flags(lflags); + if (ret) + return ret; + + for (i = 0; i < lh->numdescs; i++) { + desc = lh->descs[i]; + flagsp = &desc->flags; + + linehandle_configure_flag(flagsp, FLAG_ACTIVE_LOW, + lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW); + + linehandle_configure_flag(flagsp, FLAG_OPEN_DRAIN, + lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN); + + linehandle_configure_flag(flagsp, FLAG_OPEN_SOURCE, + lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE); + + linehandle_configure_flag(flagsp, FLAG_PULL_UP, + lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP); + + linehandle_configure_flag(flagsp, FLAG_PULL_DOWN, + lflags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN); + + linehandle_configure_flag(flagsp, FLAG_BIAS_DISABLE, + lflags & GPIOHANDLE_REQUEST_BIAS_DISABLE); + + /* + * Lines have to be requested explicitly for input + * or output, else the line will be treated "as is". + */ + if (lflags & GPIOHANDLE_REQUEST_OUTPUT) { + int val = !!gcnf.default_values[i]; + + ret = gpiod_direction_output(desc, val); + if (ret) + return ret; + } else if (lflags & GPIOHANDLE_REQUEST_INPUT) { + ret = gpiod_direction_input(desc); + if (ret) + return ret; + } + } + return 0; +} + static long linehandle_ioctl(struct file *filep, unsigned int cmd, unsigned long arg) { @@ -526,6 +593,8 @@ static long linehandle_ioctl(struct file *filep, unsigned int cmd, lh->descs, NULL, vals); + } else if (cmd == GPIOHANDLE_SET_CONFIG_IOCTL) { + return linehandle_set_config(lh, ip); } return -EINVAL; } diff --git a/include/uapi/linux/gpio.h b/include/uapi/linux/gpio.h index 7cc21c3b0839..799cf823d493 100644 --- a/include/uapi/linux/gpio.h +++ b/include/uapi/linux/gpio.h @@ -101,6 +101,24 @@ struct gpiohandle_request { }; /** + * struct gpiohandle_config - Configuration for a GPIO handle request + * @flags: updated flags for the requested GPIO lines, such as + * GPIOHANDLE_REQUEST_OUTPUT, GPIOHANDLE_REQUEST_ACTIVE_LOW etc, OR:ed + * together + * @default_values: if the GPIOHANDLE_REQUEST_OUTPUT is set in flags, + * this specifies the default output value, should be 0 (low) or + * 1 (high), anything else than 0 or 1 will be interpreted as 1 (high) + * @padding: reserved for future use and should be zero filled + */ +struct gpiohandle_config { + __u32 flags; + __u8 default_values[GPIOHANDLES_MAX]; + __u32 padding[4]; /* padding for future use */ +}; + +#define GPIOHANDLE_SET_CONFIG_IOCTL _IOWR(0xB4, 0x0a, struct gpiohandle_config) + +/** * struct gpiohandle_data - Information of values on a GPIO handle * @values: when getting the state of lines this contains the current * state of a line, when setting the state of lines these should contain |