[PATCH v1, 1/1] mailbox: mtk-cmdq: fix gce timeout issue

[Yongqiang Niu]

From: Yongqiang Niu <yongqiang.niu at mediatek.corp-partner.google.com>

1. enable gce ddr enable(gce reigster offset 0x48, bit 16 to 18) when gce work,
and disable gce ddr enable when gce work job done
2. split cmdq clk enable/disable api, and control gce ddr enable/disable
in clk enable/disable function to make sure it could protect when cmdq
is multiple used by display and mdp

Signed-off-by: Yongqiang Niu <yongqiang.niu at mediatek.corp-partner.google.com>
Signed-off-by: Allen-kh Cheng <allen-kh.cheng at mediatek.corp-partner.google.com>
---
 drivers/mailbox/mtk-cmdq-mailbox.c | 57 ++++++++++++++++++++++++++----
 1 file changed, 51 insertions(+), 6 deletions(-)

diff --git a/drivers/mailbox/mtk-cmdq-mailbox.c b/drivers/mailbox/mtk-cmdq-mailbox.c
index 2578e5aaa935..64a47470f062 100644
--- a/drivers/mailbox/mtk-cmdq-mailbox.c
+++ b/drivers/mailbox/mtk-cmdq-mailbox.c
@@ -81,6 +81,8 @@ struct cmdq {
 	u8			shift_pa;
 	bool			control_by_sw;
 	u32			gce_num;
+	atomic_t		usage;
+	spinlock_t		lock;
 };
 
 struct gce_plat {
@@ -90,6 +92,46 @@ struct gce_plat {
 	u32 gce_num;
 };
 
+static s32 cmdq_clk_enable(struct cmdq *cmdq)
+{
+	s32 usage, ret;
+	unsigned long flags;
+
+	spin_lock_irqsave(&cmdq->lock, flags);
+
+	usage = atomic_inc_return(&cmdq->usage);
+
+	ret = clk_bulk_enable(cmdq->gce_num, cmdq->clocks);
+	if (usage <=0 || ret < 0) {
+		dev_err(cmdq->mbox.dev, "ref count %d ret %d suspend %d\n",
+			usage, ret, cmdq->suspended);
+	} else if (usage == 1) {
+		if (cmdq->control_by_sw)
+			writel((0x7 << 16) + 0x7, cmdq->base + GCE_GCTL_VALUE);
+	}
+
+	spin_unlock_irqrestore(&cmdq->lock, flags);
+
+	return ret;
+}
+
+static void cmdq_clk_disable(struct cmdq *cmdq)
+{
+	s32 usage;
+
+	usage = atomic_dec_return(&cmdq->usage);
+
+	if (usage < 0) {
+		dev_err(cmdq->mbox.dev, "ref count %d suspend %d\n",
+			usage, cmdq->suspended);
+	} else if (usage == 0) {
+		if (cmdq->control_by_sw)
+			writel(0x7, cmdq->base + GCE_GCTL_VALUE);
+	}
+
+	clk_bulk_disable(cmdq->gce_num, cmdq->clocks);
+}
+
 u8 cmdq_get_shift_pa(struct mbox_chan *chan)
 {
 	struct cmdq *cmdq = container_of(chan->mbox, struct cmdq, mbox);
@@ -271,7 +313,8 @@ static void cmdq_thread_irq_handler(struct cmdq *cmdq,
 
 	if (list_empty(&thread->task_busy_list)) {
 		cmdq_thread_disable(cmdq, thread);
-		clk_bulk_disable(cmdq->gce_num, cmdq->clocks);
+
+		cmdq_clk_disable(cmdq);
 	}
 }
 
@@ -360,8 +403,7 @@ static int cmdq_mbox_send_data(struct mbox_chan *chan, void *data)
 	task->pkt = pkt;
 
 	if (list_empty(&thread->task_busy_list)) {
-		WARN_ON(clk_bulk_enable(cmdq->gce_num, cmdq->clocks));
-
+		WARN_ON(cmdq_clk_enable(cmdq) < 0);
 		/*
 		 * The thread reset will clear thread related register to 0,
 		 * including pc, end, priority, irq, suspend and enable. Thus
@@ -433,7 +475,7 @@ static void cmdq_mbox_shutdown(struct mbox_chan *chan)
 	}
 
 	cmdq_thread_disable(cmdq, thread);
-	clk_bulk_disable(cmdq->gce_num, cmdq->clocks);
+	cmdq_clk_disable(cmdq);
 
 done:
 	/*
@@ -479,7 +521,8 @@ static int cmdq_mbox_flush(struct mbox_chan *chan, unsigned long timeout)
 
 	cmdq_thread_resume(thread);
 	cmdq_thread_disable(cmdq, thread);
-	clk_bulk_disable(cmdq->gce_num, cmdq->clocks);
+
+	cmdq_clk_disable(cmdq);
 
 out:
 	spin_unlock_irqrestore(&thread->chan->lock, flags);
@@ -490,7 +533,8 @@ static int cmdq_mbox_flush(struct mbox_chan *chan, unsigned long timeout)
 	spin_unlock_irqrestore(&thread->chan->lock, flags);
 	if (readl_poll_timeout_atomic(thread->base + CMDQ_THR_ENABLE_TASK,
 				      enable, enable == 0, 1, timeout)) {
-		dev_err(cmdq->mbox.dev, "Fail to wait GCE thread 0x%x done\n",
+		dev_err(cmdq->mbox.dev,
+			"Fail to wait GCE thread 0x%x done\n",
 			(u32)(thread->base - cmdq->base));
 
 		return -EFAULT;
@@ -626,6 +670,7 @@ static int cmdq_probe(struct platform_device *pdev)
 
 	WARN_ON(clk_bulk_prepare(cmdq->gce_num, cmdq->clocks));
 
+	spin_lock_init(&cmdq->lock);
 	cmdq_init(cmdq);
 
 	return 0;
-- 
2.25.1