Commit 38ed8c88 authored by Hector Martin's avatar Hector Martin Committed by Jassi Brar
Browse files

mailbox: apple: Implement flush() operation 



This allows clients to use the atomic-safe mailbox API style.

Signed-off-by: default avatarHector Martin <marcan@marcan.st>
Signed-off-by: default avatarRussell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: default avatarJassi Brar <jaswinder.singh@linaro.org>
parent 3245cb65

drivers/mailbox/apple-mailbox.c

+27 −0
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ 
 */



#include <linux/apple-mailbox.h>

#include <linux/delay.h>

#include <linux/device.h>

#include <linux/gfp.h>

#include <linux/interrupt.h>
@@ -112,6 +113,14 @@ static bool apple_mbox_hw_can_send(struct apple_mbox *apple_mbox) 
	return !(mbox_ctrl & apple_mbox->hw->control_full);

}



static bool apple_mbox_hw_send_empty(struct apple_mbox *apple_mbox)

{

	u32 mbox_ctrl =

		readl_relaxed(apple_mbox->regs + apple_mbox->hw->a2i_control);



	return mbox_ctrl & apple_mbox->hw->control_empty;

}



static int apple_mbox_hw_send(struct apple_mbox *apple_mbox,

			      struct apple_mbox_msg *msg)

{
@@ -219,6 +228,23 @@ static irqreturn_t apple_mbox_recv_irq(int irq, void *data) 
	return IRQ_HANDLED;

}



static int apple_mbox_chan_flush(struct mbox_chan *chan, unsigned long timeout)

{

	struct apple_mbox *apple_mbox = chan->con_priv;

	unsigned long deadline = jiffies + msecs_to_jiffies(timeout);



	while (time_before(jiffies, deadline)) {

		if (apple_mbox_hw_send_empty(apple_mbox)) {

			mbox_chan_txdone(&apple_mbox->chan, 0);

			return 0;

		}



		udelay(1);

	}



	return -ETIME;

}



static int apple_mbox_chan_startup(struct mbox_chan *chan)

{

	struct apple_mbox *apple_mbox = chan->con_priv;
@@ -250,6 +276,7 @@ static void apple_mbox_chan_shutdown(struct mbox_chan *chan) 


static const struct mbox_chan_ops apple_mbox_ops = {

	.send_data = apple_mbox_chan_send_data,

	.flush = apple_mbox_chan_flush,

	.startup = apple_mbox_chan_startup,

	.shutdown = apple_mbox_chan_shutdown,

};