gpio: add new SET_CONFIG ioctl() to gpio chardev (e588bb1e) · Commits · 戴 / test

drivers/gpio/gpiolib.c

+69 −0

Original line number	Diff line number	Diff line
		@@ -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;
		}

include/uapi/linux/gpio.h

+18 −0

Original line number	Diff line number	Diff line
		@@ -100,6 +100,24 @@ struct gpiohandle_request {
		int fd;
		};

		/**
		* 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

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