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| author |   Hector Martin <marcan@marcan.st> | 2022-09-14 09:34:21 +0100 |
|---|---|---|
| committer |   Jassi Brar <jaswinder.singh@linaro.org> | 2022-09-15 13:14:01 -0500 |
| commit | 38ed8c888e94f10e3a74a931760e77c0ab9d2e48 (patch) | |
| tree | d870c3472e395a18b0b733d52197954ed9b4dfe4 | |
| parent | Merge tag 'devicetree-fixes-for-6.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux (diff) | |
| download | wireguard-linux-38ed8c888e94f10e3a74a931760e77c0ab9d2e48.tar.xz wireguard-linux-38ed8c888e94f10e3a74a931760e77c0ab9d2e48.zip | |
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>
| -rw-r--r-- | drivers/mailbox/apple-mailbox.c | 27 |
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, }; |