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authorHector Martin <marcan@marcan.st>2022-09-14 11:34:21 +0300
committerJassi Brar <jaswinder.singh@linaro.org>2022-09-15 21:14:01 +0300
commit38ed8c888e94f10e3a74a931760e77c0ab9d2e48 (patch)
treed870c3472e395a18b0b733d52197954ed9b4dfe4 /drivers/mailbox
parent3245cb65fd91cd514801bf91f5a3066d562f0ac4 (diff)
downloadlinux-38ed8c888e94f10e3a74a931760e77c0ab9d2e48.tar.xz
mailbox: apple: Implement flush() operation
This allows clients to use the atomic-safe mailbox API style. Signed-off-by: Hector Martin <marcan@marcan.st> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
Diffstat (limited to 'drivers/mailbox')
-rw-r--r--drivers/mailbox/apple-mailbox.c27
1 files changed, 27 insertions, 0 deletions
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,
};