Commit a54756cb authored by Kent Gibson's avatar Kent Gibson Committed by Bartosz Golaszewski
Browse files

gpiolib: cdev: support GPIO_V2_LINE_SET_CONFIG_IOCTL 



Add support for GPIO_V2_LINE_SET_CONFIG_IOCTL, the uAPI v2
line set config ioctl.

Signed-off-by: default avatarKent Gibson <warthog618@gmail.com>
Signed-off-by: default avatarBartosz Golaszewski <bgolaszewski@baylibre.com>
parent 73e03419

drivers/gpio/gpiolib-cdev.c

+88 −0
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ 
#include <linux/kernel.h>

#include <linux/kfifo.h>

#include <linux/module.h>

#include <linux/mutex.h>

#include <linux/pinctrl/consumer.h>

#include <linux/poll.h>

#include <linux/spinlock.h>
@@ -444,6 +445,8 @@ struct line { 
 * @seqno: the sequence number for edge events generated on all lines in

 * this line request.  Note that this is not used when @num_lines is 1, as

 * the line_seqno is then the same and is cheaper to calculate.

 * @config_mutex: mutex for serializing ioctl() calls to ensure consistency

 * of configuration, particularly multi-step accesses to desc flags.

 * @lines: the lines held by this line request, with @num_lines elements.

 */

struct linereq {
@@ -454,6 +457,7 @@ struct linereq { 
	u32 event_buffer_size;

	DECLARE_KFIFO_PTR(events, struct gpio_v2_line_event);

	atomic_t seqno;

	struct mutex config_mutex;

	struct line lines[];

};
@@ -574,6 +578,8 @@ static void edge_detector_stop(struct line *line) 
		free_irq(line->irq, line);

		line->irq = 0;

	}



	line->eflags = 0;

}



static int edge_detector_setup(struct line *line,
@@ -615,6 +621,17 @@ static int edge_detector_setup(struct line *line, 
	return 0;

}



static int edge_detector_update(struct line *line, u64 eflags,

				bool polarity_change)

{

	if ((line->eflags == eflags) && !polarity_change)

		return 0;



	edge_detector_stop(line);



	return edge_detector_setup(line, eflags);

}



static u64 gpio_v2_line_config_flags(struct gpio_v2_line_config *lc,

				     unsigned int line_idx)

{
@@ -799,6 +816,74 @@ static long linereq_get_values(struct linereq *lr, void __user *ip) 
	return 0;

}



static long linereq_set_config_unlocked(struct linereq *lr,

					struct gpio_v2_line_config *lc)

{

	struct gpio_desc *desc;

	unsigned int i;

	u64 flags;

	bool polarity_change;

	int ret;



	for (i = 0; i < lr->num_lines; i++) {

		desc = lr->lines[i].desc;

		flags = gpio_v2_line_config_flags(lc, i);

		polarity_change =

			(!!test_bit(FLAG_ACTIVE_LOW, &desc->flags) !=

			 ((flags & GPIO_V2_LINE_FLAG_ACTIVE_LOW) != 0));



		gpio_v2_line_config_flags_to_desc_flags(flags, &desc->flags);

		/*

		 * Lines have to be requested explicitly for input

		 * or output, else the line will be treated "as is".

		 */

		if (flags & GPIO_V2_LINE_FLAG_OUTPUT) {

			int val = gpio_v2_line_config_output_value(lc, i);



			edge_detector_stop(&lr->lines[i]);

			ret = gpiod_direction_output(desc, val);

			if (ret)

				return ret;

		} else if (flags & GPIO_V2_LINE_FLAG_INPUT) {

			ret = gpiod_direction_input(desc);

			if (ret)

				return ret;



			ret = edge_detector_update(&lr->lines[i],

					flags & GPIO_V2_LINE_EDGE_FLAGS,

					polarity_change);

			if (ret)

				return ret;

		}



		blocking_notifier_call_chain(&desc->gdev->notifier,

					     GPIO_V2_LINE_CHANGED_CONFIG,

					     desc);

	}

	return 0;

}



static long linereq_set_config(struct linereq *lr, void __user *ip)

{

	struct gpio_v2_line_config lc;

	int ret;



	if (copy_from_user(&lc, ip, sizeof(lc)))

		return -EFAULT;



	ret = gpio_v2_line_config_validate(&lc, lr->num_lines);

	if (ret)

		return ret;



	mutex_lock(&lr->config_mutex);



	ret = linereq_set_config_unlocked(lr, &lc);



	mutex_unlock(&lr->config_mutex);



	return ret;

}



static long linereq_ioctl(struct file *file, unsigned int cmd,

			  unsigned long arg)

{
@@ -807,6 +892,8 @@ static long linereq_ioctl(struct file *file, unsigned int cmd, 


	if (cmd == GPIO_V2_LINE_GET_VALUES_IOCTL)

		return linereq_get_values(lr, ip);

	else if (cmd == GPIO_V2_LINE_SET_CONFIG_IOCTL)

		return linereq_set_config(lr, ip);



	return -EINVAL;

}
@@ -968,6 +1055,7 @@ static int linereq_create(struct gpio_device *gdev, void __user *ip) 
		}

	}



	mutex_init(&lr->config_mutex);

	init_waitqueue_head(&lr->wait);

	lr->event_buffer_size = ulr.event_buffer_size;

	if (lr->event_buffer_size == 0)