Commit aac997df authored by Christian Gromm's avatar Christian Gromm Committed by Greg Kroah-Hartman
Browse files

staging: most: add poll syscall to AIM cdev 



This patch adds the implementation of the poll syscall to the AIM cdev.
To have the full functionality, a helper function is needed in the
core module to retrieve the instantaneous availability of tx buffers.

Signed-off-by: default avatarChristian Gromm <christian.gromm@microchip.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 48ab5a33

drivers/staging/most/aim-cdev/cdev.c

+26 −0
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ 
#include <linux/slab.h>

#include <linux/device.h>

#include <linux/cdev.h>

#include <linux/poll.h>

#include <linux/kfifo.h>

#include <linux/uaccess.h>

#include <linux/idr.h>
@@ -31,6 +32,7 @@ static struct most_aim cdev_aim; 


struct aim_channel {

	wait_queue_head_t wq;

	wait_queue_head_t poll_wq;

	struct cdev cdev;

	struct device *dev;

	struct mutex io_mutex;
@@ -271,6 +273,28 @@ aim_read(struct file *filp, char __user *buf, size_t count, loff_t *offset) 
	return retval;

}



static inline bool __must_check IS_ERR_OR_FALSE(int x)

{

	return x <= 0;

}



static unsigned int aim_poll(struct file *filp, poll_table *wait)

{

	struct aim_channel *c = filp->private_data;

	unsigned int mask = 0;



	poll_wait(filp, &c->poll_wq, wait);



	if (c->cfg->direction == MOST_CH_RX) {

		if (!kfifo_is_empty(&c->fifo))

			mask |= POLLIN | POLLRDNORM;

	} else {

		if (!IS_ERR_OR_FALSE(channel_has_mbo(c->iface, c->channel_id)))

			mask |= POLLOUT | POLLWRNORM;

	}

	return mask;

}



/**

 * Initialization of struct file_operations

 */
@@ -280,6 +304,7 @@ static const struct file_operations channel_fops = { 
	.write = aim_write,

	.open = aim_open,

	.release = aim_close,

	.poll = aim_poll,

};



/**
@@ -434,6 +459,7 @@ static int aim_probe(struct most_interface *iface, int channel_id, 
		goto error_alloc_kfifo;

	}

	init_waitqueue_head(&channel->wq);

	init_waitqueue_head(&channel->poll_wq);

	mutex_init(&channel->io_mutex);

	spin_lock_irqsave(&ch_list_lock, cl_flags);

	list_add_tail(&channel->list, &channel_list);

drivers/staging/most/mostcore/core.c

+16 −0
Original line number Diff line number Diff line
@@ -1383,6 +1383,22 @@ most_c_obj *get_channel_by_iface(struct most_interface *iface, int id) 
	return i->channel[id];

}



int channel_has_mbo(struct most_interface *iface, int id)

{

	struct most_c_obj *c = get_channel_by_iface(iface, id);

	unsigned long flags;

	int empty;



	if (unlikely(!c))

		return -EINVAL;



	spin_lock_irqsave(&c->fifo_lock, flags);

	empty = list_empty(&c->fifo);

	spin_unlock_irqrestore(&c->fifo_lock, flags);

	return !empty;

}

EXPORT_SYMBOL_GPL(channel_has_mbo);



/**

 * most_get_mbo - get pointer to an MBO of pool

 * @iface: pointer to interface instance

drivers/staging/most/mostcore/mostcore.h

+1 −0
Original line number Diff line number Diff line
@@ -311,6 +311,7 @@ int most_deregister_aim(struct most_aim *aim); 
struct mbo *most_get_mbo(struct most_interface *iface, int channel_idx,

			 struct most_aim *);

void most_put_mbo(struct mbo *mbo);

int channel_has_mbo(struct most_interface *iface, int channel_idx);

int most_start_channel(struct most_interface *iface, int channel_idx,

		       struct most_aim *);

int most_stop_channel(struct most_interface *iface, int channel_idx,