mailbox: mediatek: cmdq: clear the event in cmdq initial flow

GCE hardware stored event information in own internal sysram,
if the initial value in those sysram is not zero value
it will cause a situation that gce can wait the event immediately
after client ask gce to wait event but not really trigger the
corresponding hardware.

In order to make sure that the wait event function is
exactly correct, we need to clear the sysram value in
cmdq initial flow.

Fixes: 623a6143 ("mailbox: mediatek: Add Mediatek CMDQ driver")
Signed-off-by: Bibby Hsieh <bibby.hsieh@mediatek.com>
Reviewed-by: CK Hu <ck.hu@mediatek.com>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

drivers/mailbox/mtk-cmdq-mailbox.c

@@ -21,6 +21,7 @@
 #define CMDQ_NUM_CMD(t)			(t->cmd_buf_size / CMDQ_INST_SIZE)
 
 #define CMDQ_CURR_IRQ_STATUS		0x10
+#define CMDQ_SYNC_TOKEN_UPDATE		0x68
 #define CMDQ_THR_SLOT_CYCLES		0x30
 #define CMDQ_THR_BASE			0x100
 #define CMDQ_THR_SIZE			0x80
@@ -104,8 +105,12 @@ static void cmdq_thread_resume(struct cmdq_thread *thread)
 
 static void cmdq_init(struct cmdq *cmdq)
 {
+	int i;
+
 	WARN_ON(clk_enable(cmdq->clock) < 0);
 	writel(CMDQ_THR_ACTIVE_SLOT_CYCLES, cmdq->base + CMDQ_THR_SLOT_CYCLES);
+	for (i = 0; i <= CMDQ_MAX_EVENT; i++)
+		writel(i, cmdq->base + CMDQ_SYNC_TOKEN_UPDATE);
 	clk_disable(cmdq->clock);
 }
 

include/linux/mailbox/mtk-cmdq-mailbox.h

@@ -20,6 +20,9 @@
 #define CMDQ_WFE_WAIT			BIT(15)
 #define CMDQ_WFE_WAIT_VALUE		0x1
 
+/** cmdq event maximum */
+#define CMDQ_MAX_EVENT			0x3ff
+
 /*
  * CMDQ_CODE_MASK:
  *   set write mask

include/linux/soc/mediatek/mtk-cmdq.h

@@ -13,9 +13,6 @@
 
 #define CMDQ_NO_TIMEOUT		0xffffffffu
 
-/** cmdq event maximum */
-#define CMDQ_MAX_EVENT				0x3ff
-
 struct cmdq_pkt;
 
 struct cmdq_client {