[PATCH v2 5/9] soc: mailbox: Add cmdq_pkt_finalize_loop to support looping cmd with irq

[Jason-JH.Lin]

Add cmdq_pkt_finalize_loop to CMDQ driver.

cmdq_pkt_finalize_loop appends end of command(EOC) instruction and
jump to start of command buffer instruction to make the command
buffer loopable.

GCE irq occurs when GCE executes to the EOC instruction.
CMDQ client can use a loop flag to mark the CMDQ packet as looping
packet. If the CMDQ packet is a loopping packet, GCE irq handler
won't delete the CMDQ task and disable the GCE thread.

Signed-off-by: Jason-JH.Lin <jason-jh.lin at mediatek.com>
---
 drivers/mailbox/mtk-cmdq-mailbox.c       | 11 +++++++++++
 drivers/soc/mediatek/mtk-cmdq-helper.c   | 23 +++++++++++++++++++++++
 include/linux/mailbox/mtk-cmdq-mailbox.h |  1 +
 include/linux/soc/mediatek/mtk-cmdq.h    |  8 ++++++++
 4 files changed, 43 insertions(+)

diff --git a/drivers/mailbox/mtk-cmdq-mailbox.c b/drivers/mailbox/mtk-cmdq-mailbox.c
index 4d62b07c1411..56fe01cd9731 100644
--- a/drivers/mailbox/mtk-cmdq-mailbox.c
+++ b/drivers/mailbox/mtk-cmdq-mailbox.c
@@ -264,6 +264,17 @@ static void cmdq_thread_irq_handler(struct cmdq *cmdq,
 
 	curr_pa = readl(thread->base + CMDQ_THR_CURR_ADDR) << cmdq->pdata->shift;
 
+	task = list_first_entry_or_null(&thread->task_busy_list,
+					struct cmdq_task, list_entry);
+	if (task && task->pkt->loop) {
+		struct cmdq_cb_data data;
+
+		data.sta = err;
+		data.pkt = task->pkt;
+		mbox_chan_received_data(task->thread->chan, &data);
+		return;
+	}
+
 	list_for_each_entry_safe(task, tmp, &thread->task_busy_list,
 				 list_entry) {
 		task_end_pa = task->pa_base + task->pkt->cmd_buf_size;
diff --git a/drivers/soc/mediatek/mtk-cmdq-helper.c b/drivers/soc/mediatek/mtk-cmdq-helper.c
index 4be2a18a4a02..bbb127620bb3 100644
--- a/drivers/soc/mediatek/mtk-cmdq-helper.c
+++ b/drivers/soc/mediatek/mtk-cmdq-helper.c
@@ -475,6 +475,29 @@ int cmdq_pkt_finalize(struct cmdq_pkt *pkt)
 }
 EXPORT_SYMBOL(cmdq_pkt_finalize);
 
+int cmdq_pkt_finalize_loop(struct cmdq_pkt *pkt)
+{
+	struct cmdq_instruction inst = { {0} };
+	int err;
+
+	/* insert EOC and generate IRQ for each command iteration */
+	inst.op = CMDQ_CODE_EOC;
+	inst.value = CMDQ_EOC_IRQ_EN;
+	err = cmdq_pkt_append_command(pkt, inst);
+	if (err < 0)
+		return err;
+
+	/* JUMP to start of pkt */
+	err = cmdq_pkt_jump(pkt, pkt->pa_base);
+	if (err < 0)
+		return err;
+
+	pkt->loop = true;
+
+	return err;
+}
+EXPORT_SYMBOL(cmdq_pkt_finalize_loop);
+
 int cmdq_pkt_flush_async(struct cmdq_pkt *pkt)
 {
 	int err;
diff --git a/include/linux/mailbox/mtk-cmdq-mailbox.h b/include/linux/mailbox/mtk-cmdq-mailbox.h
index a8f0070c7aa9..f78a08e7c6ed 100644
--- a/include/linux/mailbox/mtk-cmdq-mailbox.h
+++ b/include/linux/mailbox/mtk-cmdq-mailbox.h
@@ -76,6 +76,7 @@ struct cmdq_pkt {
 	size_t			cmd_buf_size; /* command occupied size */
 	size_t			buf_size; /* real buffer size */
 	void			*cl;
+	bool			loop;
 };
 
 u8 cmdq_get_shift_pa(struct mbox_chan *chan);
diff --git a/include/linux/soc/mediatek/mtk-cmdq.h b/include/linux/soc/mediatek/mtk-cmdq.h
index 4262594a0d18..deb2e1920a0e 100644
--- a/include/linux/soc/mediatek/mtk-cmdq.h
+++ b/include/linux/soc/mediatek/mtk-cmdq.h
@@ -328,6 +328,14 @@ int cmdq_pkt_jump(struct cmdq_pkt *pkt, dma_addr_t addr);
  */
 int cmdq_pkt_finalize(struct cmdq_pkt *pkt);
 
+/**
+ * cmdq_pkt_finalize_loop() - Append EOC and jump to start command.
+ * @pkt:	the CMDQ packet
+ *
+ * Return: 0 for success; else the error code is returned
+ */
+int cmdq_pkt_finalize_loop(struct cmdq_pkt *pkt);
+
 /**
  * cmdq_pkt_flush_async() - trigger CMDQ to asynchronously execute the CMDQ
  *                          packet and call back at the end of done packet
-- 
2.18.0