lkml.org 
[lkml]   [2022]   [May]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 6/7] mailbox: apple: Implement flush() operation
Date
This allows clients to use the atomic-safe mailbox API style.

Signed-off-by: Hector Martin <marcan@marcan.st>
---
drivers/mailbox/apple-mailbox.c | 27 +++++++++++++++++++++++++++
1 file changed, 27 insertions(+)

diff --git a/drivers/mailbox/apple-mailbox.c b/drivers/mailbox/apple-mailbox.c
index 496c4951ccb1..33e7acf71e3e 100644
--- a/drivers/mailbox/apple-mailbox.c
+++ b/drivers/mailbox/apple-mailbox.c
@@ -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,
};
--
2.35.1
\
 
 \ /
  Last update: 2022-05-02 11:04    [W:0.059 / U:0.420 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site