Re: [PATCH v21 4/4] soc: mediatek: Add Mediatek CMDQ helper

[houlong wei]

On Wed, 2018-02-21 at 16:05 +0800, CK Hu wrote:
> Hi, Houlong:
> 
> I've one more inline comment.
> 
> On Wed, 2018-01-31 at 15:28 +0800, houlong.wei@xxxxxxxxxxxx wrote:
> > From: "hs.liao@xxxxxxxxxxxx" <hs.liao@xxxxxxxxxxxx>
> > 
> > Add Mediatek CMDQ helper to create CMDQ packet and assemble GCE op code.
> > 
> > Signed-off-by: Houlong Wei <houlong.wei@xxxxxxxxxxxx>
> > Signed-off-by: HS Liao <hs.liao@xxxxxxxxxxxx>
> > ---
> >  drivers/soc/mediatek/Kconfig           |   12 ++
> >  drivers/soc/mediatek/Makefile          |    1 +
> >  drivers/soc/mediatek/mtk-cmdq-helper.c |  322 ++++++++++++++++++++++++++++++++
> >  include/linux/soc/mediatek/mtk-cmdq.h  |  174 +++++++++++++++++
> >  4 files changed, 509 insertions(+)
> >  create mode 100644 drivers/soc/mediatek/mtk-cmdq-helper.c
> >  create mode 100644 include/linux/soc/mediatek/mtk-cmdq.h
> > 
> > diff --git a/drivers/soc/mediatek/Kconfig b/drivers/soc/mediatek/Kconfig
> > index a7d0667..e66582e 100644
> > --- a/drivers/soc/mediatek/Kconfig
> > +++ b/drivers/soc/mediatek/Kconfig
> > @@ -4,6 +4,18 @@
> >  menu "MediaTek SoC drivers"
> >  	depends on ARCH_MEDIATEK || COMPILE_TEST
> >  
> > +config MTK_CMDQ
> > +	bool "MediaTek CMDQ Support"
> > +	depends on ARM64 && ( ARCH_MEDIATEK || COMPILE_TEST )
> > +	select MAILBOX
> > +	select MTK_CMDQ_MBOX
> > +	select MTK_INFRACFG
> > +	help
> > +	  Say yes here to add support for the MediaTek Command Queue (CMDQ)
> > +	  driver. The CMDQ is used to help read/write registers with critical
> > +	  time limitation, such as updating display configuration during the
> > +	  vblank.
> > +
> >  config MTK_INFRACFG
> >  	bool "MediaTek INFRACFG Support"
> >  	select REGMAP
> > diff --git a/drivers/soc/mediatek/Makefile b/drivers/soc/mediatek/Makefile
> > index 12998b0..64ce5ee 100644
> > --- a/drivers/soc/mediatek/Makefile
> > +++ b/drivers/soc/mediatek/Makefile
> > @@ -1,3 +1,4 @@
> > +obj-$(CONFIG_MTK_CMDQ) += mtk-cmdq-helper.o
> >  obj-$(CONFIG_MTK_INFRACFG) += mtk-infracfg.o
> >  obj-$(CONFIG_MTK_PMIC_WRAP) += mtk-pmic-wrap.o
> >  obj-$(CONFIG_MTK_SCPSYS) += mtk-scpsys.o
> > diff --git a/drivers/soc/mediatek/mtk-cmdq-helper.c b/drivers/soc/mediatek/mtk-cmdq-helper.c
> > new file mode 100644
> > index 0000000..80d0558
> > --- /dev/null
> > +++ b/drivers/soc/mediatek/mtk-cmdq-helper.c
> > @@ -0,0 +1,322 @@
> > +/*
> > + * Copyright (c) 2015 MediaTek Inc.
> > + *
> > + * This program is free software; you can redistribute it and/or modify
> > + * it under the terms of the GNU General Public License version 2 as
> > + * published by the Free Software Foundation.
> > + *
> > + * This program is distributed in the hope that it will be useful,
> > + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> > + * GNU General Public License for more details.
> > + */
> > +
> > +#include <linux/completion.h>
> > +#include <linux/errno.h>
> > +#include <linux/of_address.h>
> > +#include <linux/dma-mapping.h>
> > +#include <linux/mailbox_controller.h>
> > +#include <linux/soc/mediatek/mtk-cmdq.h>
> > +
> > +#define CMDQ_ARG_A_WRITE_MASK	0xffff
> > +#define CMDQ_WRITE_ENABLE_MASK	BIT(0)
> > +#define CMDQ_EOC_IRQ_EN		BIT(0)
> > +#define CMDQ_EOC_CMD		((u64)((CMDQ_CODE_EOC << CMDQ_OP_CODE_SHIFT)) \
> > +				<< 32 | CMDQ_EOC_IRQ_EN)
> > +
> > +struct cmdq_subsys {
> > +	u32	base;
> > +	int	id;
> > +};
> > +
> > +static const struct cmdq_subsys gce_subsys[] = {
> > +	{0x1400, 1},
> > +	{0x1401, 2},
> > +	{0x1402, 3},
> > +};
> > +
> > +static int cmdq_subsys_base_to_id(u32 base)
> > +{
> > +	int i;
> > +
> > +	for (i = 0; i < ARRAY_SIZE(gce_subsys); i++)
> > +		if (gce_subsys[i].base == base)
> > +			return gce_subsys[i].id;
> > +	return -EFAULT;
> > +}
> > +
> > +static int cmdq_pkt_realloc_cmd_buffer(struct cmdq_pkt *pkt, size_t size)
> > +{
> > +	void *new_buf;
> > +
> > +	new_buf = krealloc(pkt->va_base, size, GFP_KERNEL | __GFP_ZERO);
> > +	if (!new_buf)
> > +		return -ENOMEM;
> > +	pkt->va_base = new_buf;
> > +	pkt->buf_size = size;
> > +	return 0;
> > +}
> > +
> > +struct cmdq_base *cmdq_register_device(struct device *dev)
> > +{
> > +	struct cmdq_base *cmdq_base;
> > +	struct resource res;
> > +	int subsys;
> > +	u32 base;
> > +
> > +	if (of_address_to_resource(dev->of_node, 0, &res))
> > +		return NULL;
> > +	base = (u32)res.start;
> > +
> > +	subsys = cmdq_subsys_base_to_id(base >> 16);
> > +	if (subsys < 0)
> > +		return NULL;
> > +
> > +	cmdq_base = devm_kmalloc(dev, sizeof(*cmdq_base), GFP_KERNEL);
> > +	if (!cmdq_base)
> > +		return NULL;
> > +	cmdq_base->subsys = subsys;
> > +	cmdq_base->base = base;
> > +
> > +	return cmdq_base;
> > +}
> > +EXPORT_SYMBOL(cmdq_register_device);
> > +
> > +struct cmdq_client *cmdq_mbox_create(struct device *dev, int index)
> > +{
> > +	struct cmdq_client *client;
> > +
> > +	client = kzalloc(sizeof(*client), GFP_KERNEL);
> > +	client->client.dev = dev;
> > +	client->client.tx_block = false;
> > +	client->chan = mbox_request_channel(&client->client, index);
> > +	return client;
> > +}
> > +EXPORT_SYMBOL(cmdq_mbox_create);
> > +
> > +void cmdq_mbox_destroy(struct cmdq_client *client)
> > +{
> > +	mbox_free_channel(client->chan);
> > +	kfree(client);
> > +}
> > +EXPORT_SYMBOL(cmdq_mbox_destroy);
> > +
> > +int cmdq_pkt_create(struct cmdq_pkt **pkt_ptr)
> > +{
> > +	struct cmdq_pkt *pkt;
> > +	int err;
> > +
> > +	pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
> > +	if (!pkt)
> > +		return -ENOMEM;
> > +	err = cmdq_pkt_realloc_cmd_buffer(pkt, PAGE_SIZE);
> > +	if (err < 0) {
> > +		kfree(pkt);
> > +		return err;
> > +	}
> > +	*pkt_ptr = pkt;
> > +	return 0;
> > +}
> > +EXPORT_SYMBOL(cmdq_pkt_create);
> > +
> > +void cmdq_pkt_destroy(struct cmdq_pkt *pkt)
> > +{
> > +	kfree(pkt->va_base);
> > +	kfree(pkt);
> > +}
> > +EXPORT_SYMBOL(cmdq_pkt_destroy);
> > +
> > +static bool cmdq_pkt_is_finalized(struct cmdq_pkt *pkt)
> > +{
> > +	u64 *expect_eoc;
> > +
> > +	if (pkt->cmd_buf_size < CMDQ_INST_SIZE << 1)
> > +		return false;
> > +
> > +	expect_eoc = pkt->va_base + pkt->cmd_buf_size - (CMDQ_INST_SIZE << 1);
> > +	if (*expect_eoc == CMDQ_EOC_CMD)
> > +		return true;
> > +
> > +	return false;
> > +}
> > +
> > +static int cmdq_pkt_append_command(struct cmdq_pkt *pkt, enum cmdq_code code,
> > +				   u32 arg_a, u32 arg_b)
> > +{
> > +	u64 *cmd_ptr;
> > +	int err;
> > +
> > +	if (WARN_ON(cmdq_pkt_is_finalized(pkt)))
> > +		return -EBUSY;
> > +	if (unlikely(pkt->cmd_buf_size + CMDQ_INST_SIZE > pkt->buf_size)) {
> > +		err = cmdq_pkt_realloc_cmd_buffer(pkt, pkt->buf_size << 1);
> 
> In your design, the command buffer is frequently allocated and freed.
> But client may not want this mechanism because it have penalty on CPU
> loading and may have risk of allocation failure. The client may
> pre-allocate the command buffer and reuse it. So it's better to let
> client decide which buffer management it want. That means cmdq helper do
> not allocate command buffer and do not reallocate it. The working flow
> would be:
> 
> For client that want to pre-allocate buffer:
> (1) Client pre-allocate a command buffer with a pre-calculated size.
> (Programmer should make sure that all command would not exceed this
> size)
> (2) Client use cmdq helper function to generate command in command
> buffer. If command buffer is full, helper still increase
> pkt->cmd_buf_size but do not write command into command buffer.
> (3) When client flush packet, cmdq helper could check whether
> pkt->cmd_buf_size is greater than pkt->buf_size, if so, return error and
> programmer should modify the pre-calculated size in step (1).
> (4) Wait for command done.
> (5) Set pkt->cmd_buf_size to zero and directly goto step (2) to reuse
> this command buffer.
> 
> For client that want to dynamically allocate buffer:
> (1) Client dynamically allocate a command buffer with a initial size,
> for example, 1024 bytes.
> (2) Client use cmdq helper function to generate command in command
> buffer. If command buffer is full, helper still increase
> pkt->cmd_buf_size but do not write command into command buffer.
> (3) When client flush packet, cmdq helper could check whether
> pkt->cmd_buf_size is greater than pkt->buf_size, if so, return error and
> client goto step (1) and reallocate a command buffer with pkt->buf_size.
> (4) Wait for command done.
> (5) Free the command buffer.
> 
> Because the reallocation is so complicated, for client that want to
> dynamically allocate buffer, the initial buffer size could also be
> pre-calculated that you need not to reallocate it. Once the buffer is
> full, programmer should also fix the accurate buffer size.
> 
> Regards,
> CK
> 

Hi CK, thanks for your explanation and suggestion. Currently, the cmdq
buffer is allocated in cmdq_pkt_create and its initial size is
PAGE_SIZE. In most case of display scenario, PAGE_SIZE(4096) bytes are
enough.

> > +		if (err < 0)
> > +			return err;
> > +	}
> > +	cmd_ptr = pkt->va_base + pkt->cmd_buf_size;
> > +	(*cmd_ptr) = (u64)((code << CMDQ_OP_CODE_SHIFT) | arg_a) << 32 | arg_b;
> > +	pkt->cmd_buf_size += CMDQ_INST_SIZE;
> > +	return 0;
> > +}
> > +
> > +int cmdq_pkt_write(struct cmdq_pkt *pkt, u32 value, struct cmdq_base *base,
> > +		   u32 offset)
> > +{
> > +	u32 arg_a = ((base->base + offset) & CMDQ_ARG_A_WRITE_MASK) |
> > +		    (base->subsys << CMDQ_SUBSYS_SHIFT);
> > +	return cmdq_pkt_append_command(pkt, CMDQ_CODE_WRITE, arg_a, value);
> > +}
> > +EXPORT_SYMBOL(cmdq_pkt_write);
> > +
> > +int cmdq_pkt_write_mask(struct cmdq_pkt *pkt, u32 value,
> > +			struct cmdq_base *base, u32 offset, u32 mask)
> > +{
> > +	u32 offset_mask = offset;
> > +	int err;
> > +
> > +	if (mask != 0xffffffff) {
> > +		err = cmdq_pkt_append_command(pkt, CMDQ_CODE_MASK, 0, ~mask);
> > +		if (err < 0)
> > +			return err;
> > +		offset_mask |= CMDQ_WRITE_ENABLE_MASK;
> > +	}
> > +	return cmdq_pkt_write(pkt, value, base, offset_mask);
> > +}
> > +EXPORT_SYMBOL(cmdq_pkt_write_mask);
> > +
> > +static const u32 cmdq_event_value[CMDQ_MAX_EVENT] = {
> > +	/* Display start of frame(SOF) events */
> > +	[CMDQ_EVENT_DISP_OVL0_SOF] = 11,
> > +	[CMDQ_EVENT_DISP_OVL1_SOF] = 12,
> > +	[CMDQ_EVENT_DISP_RDMA0_SOF] = 13,
> > +	[CMDQ_EVENT_DISP_RDMA1_SOF] = 14,
> > +	[CMDQ_EVENT_DISP_RDMA2_SOF] = 15,
> > +	[CMDQ_EVENT_DISP_WDMA0_SOF] = 16,
> > +	[CMDQ_EVENT_DISP_WDMA1_SOF] = 17,
> > +	/* Display end of frame(EOF) events */
> > +	[CMDQ_EVENT_DISP_OVL0_EOF] = 39,
> > +	[CMDQ_EVENT_DISP_OVL1_EOF] = 40,
> > +	[CMDQ_EVENT_DISP_RDMA0_EOF] = 41,
> > +	[CMDQ_EVENT_DISP_RDMA1_EOF] = 42,
> > +	[CMDQ_EVENT_DISP_RDMA2_EOF] = 43,
> > +	[CMDQ_EVENT_DISP_WDMA0_EOF] = 44,
> > +	[CMDQ_EVENT_DISP_WDMA1_EOF] = 45,
> > +	/* Mutex end of frame(EOF) events */
> > +	[CMDQ_EVENT_MUTEX0_STREAM_EOF] = 53,
> > +	[CMDQ_EVENT_MUTEX1_STREAM_EOF] = 54,
> > +	[CMDQ_EVENT_MUTEX2_STREAM_EOF] = 55,
> > +	[CMDQ_EVENT_MUTEX3_STREAM_EOF] = 56,
> > +	[CMDQ_EVENT_MUTEX4_STREAM_EOF] = 57,
> > +	/* Display underrun events */
> > +	[CMDQ_EVENT_DISP_RDMA0_UNDERRUN] = 63,
> > +	[CMDQ_EVENT_DISP_RDMA1_UNDERRUN] = 64,
> > +	[CMDQ_EVENT_DISP_RDMA2_UNDERRUN] = 65,
> > +};
> > +
> > +int cmdq_pkt_wfe(struct cmdq_pkt *pkt, enum cmdq_event event)
> > +{
> > +	u32 arg_b;
> > +
> > +	if (event >= CMDQ_MAX_EVENT || event < 0)
> > +		return -EINVAL;
> > +
> > +	/*
> > +	 * WFE arg_b
> > +	 * bit 0-11: wait value
> > +	 * bit 15: 1 - wait, 0 - no wait
> > +	 * bit 16-27: update value
> > +	 * bit 31: 1 - update, 0 - no update
> > +	 */
> > +	arg_b = CMDQ_WFE_UPDATE | CMDQ_WFE_WAIT | CMDQ_WFE_WAIT_VALUE;
> > +	return cmdq_pkt_append_command(pkt, CMDQ_CODE_WFE,
> > +			cmdq_event_value[event], arg_b);
> > +}
> > +EXPORT_SYMBOL(cmdq_pkt_wfe);
> > +
> > +int cmdq_pkt_clear_event(struct cmdq_pkt *pkt, enum cmdq_event event)
> > +{
> > +	if (event >= CMDQ_MAX_EVENT || event < 0)
> > +		return -EINVAL;
> > +
> > +	return cmdq_pkt_append_command(pkt, CMDQ_CODE_WFE,
> > +			cmdq_event_value[event], CMDQ_WFE_UPDATE);
> > +}
> > +EXPORT_SYMBOL(cmdq_pkt_clear_event);
> > +
> > +static int cmdq_pkt_finalize(struct cmdq_pkt *pkt)
> > +{
> > +	int err;
> > +
> > +	if (cmdq_pkt_is_finalized(pkt))
> > +		return 0;
> > +
> > +	/* insert EOC and generate IRQ for each command iteration */
> > +	err = cmdq_pkt_append_command(pkt, CMDQ_CODE_EOC, 0, CMDQ_EOC_IRQ_EN);
> > +	if (err < 0)
> > +		return err;
> > +
> > +	/* JUMP to end */
> > +	err = cmdq_pkt_append_command(pkt, CMDQ_CODE_JUMP, 0, CMDQ_JUMP_PASS);
> > +	if (err < 0)
> > +		return err;
> > +
> > +	return 0;
> > +}
> > +
> > +int cmdq_pkt_flush_async(struct cmdq_client *client, struct cmdq_pkt *pkt,
> > +			 cmdq_async_flush_cb cb, void *data)
> > +{
> > +	int err;
> > +	struct device *dev;
> > +	dma_addr_t dma_addr;
> > +
> > +	err = cmdq_pkt_finalize(pkt);
> > +	if (err < 0)
> > +		return err;
> > +
> > +	dev = client->chan->mbox->dev;
> > +	dma_addr = dma_map_single(dev, pkt->va_base, pkt->cmd_buf_size,
> > +		DMA_TO_DEVICE);
> > +	if (dma_mapping_error(dev, dma_addr)) {
> > +		dev_err(client->chan->mbox->dev, "dma map failed\n");
> > +		return -ENOMEM;
> > +	}
> > +
> > +	pkt->pa_base = dma_addr;
> > +	pkt->cb.cb = cb;
> > +	pkt->cb.data = data;
> > +
> > +	mbox_send_message(client->chan, pkt);
> > +	/* We can send next packet immediately, so just call txdone. */
> > +	mbox_client_txdone(client->chan, 0);
> > +
> > +	return 0;
> > +}
> > +EXPORT_SYMBOL(cmdq_pkt_flush_async);
> > +
> > +struct cmdq_flush_completion {
> > +	struct completion cmplt;
> > +	bool err;
> > +};
> > +
> > +static void cmdq_pkt_flush_cb(struct cmdq_cb_data data)
> > +{
> > +	struct cmdq_flush_completion *cmplt = data.data;
> > +
> > +	cmplt->err = data.err;
> > +	complete(&cmplt->cmplt);
> > +}
> > +
> > +int cmdq_pkt_flush(struct cmdq_client *client, struct cmdq_pkt *pkt)
> > +{
> > +	struct cmdq_flush_completion cmplt;
> > +	int err;
> > +
> > +	init_completion(&cmplt.cmplt);
> > +	err = cmdq_pkt_flush_async(client, pkt, cmdq_pkt_flush_cb, &cmplt);
> > +	if (err < 0)
> > +		return err;
> > +	wait_for_completion(&cmplt.cmplt);
> > +	return cmplt.err ? -EFAULT : 0;
> > +}
> > +EXPORT_SYMBOL(cmdq_pkt_flush);
> > diff --git a/include/linux/soc/mediatek/mtk-cmdq.h b/include/linux/soc/mediatek/mtk-cmdq.h
> > new file mode 100644
> > index 0000000..5b35d73
> > --- /dev/null
> > +++ b/include/linux/soc/mediatek/mtk-cmdq.h
> > @@ -0,0 +1,174 @@
> > +/*
> > + * Copyright (c) 2015 MediaTek Inc.
> > + *
> > + * This program is free software; you can redistribute it and/or modify
> > + * it under the terms of the GNU General Public License version 2 as
> > + * published by the Free Software Foundation.
> > + *
> > + * This program is distributed in the hope that it will be useful,
> > + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> > + * GNU General Public License for more details.
> > + */
> > +
> > +#ifndef __MTK_CMDQ_H__
> > +#define __MTK_CMDQ_H__
> > +
> > +#include <linux/mailbox_client.h>
> > +#include <linux/mailbox/mtk-cmdq-mailbox.h>
> > +
> > +/* display events in command queue(CMDQ) */
> > +enum cmdq_event {
> > +	/* Display start of frame(SOF) events */
> > +	CMDQ_EVENT_DISP_OVL0_SOF,
> > +	CMDQ_EVENT_DISP_OVL1_SOF,
> > +	CMDQ_EVENT_DISP_RDMA0_SOF,
> > +	CMDQ_EVENT_DISP_RDMA1_SOF,
> > +	CMDQ_EVENT_DISP_RDMA2_SOF,
> > +	CMDQ_EVENT_DISP_WDMA0_SOF,
> > +	CMDQ_EVENT_DISP_WDMA1_SOF,
> > +	/* Display end of frame(EOF) events */
> > +	CMDQ_EVENT_DISP_OVL0_EOF,
> > +	CMDQ_EVENT_DISP_OVL1_EOF,
> > +	CMDQ_EVENT_DISP_RDMA0_EOF,
> > +	CMDQ_EVENT_DISP_RDMA1_EOF,
> > +	CMDQ_EVENT_DISP_RDMA2_EOF,
> > +	CMDQ_EVENT_DISP_WDMA0_EOF,
> > +	CMDQ_EVENT_DISP_WDMA1_EOF,
> > +	/* Mutex end of frame(EOF) events */
> > +	CMDQ_EVENT_MUTEX0_STREAM_EOF,
> > +	CMDQ_EVENT_MUTEX1_STREAM_EOF,
> > +	CMDQ_EVENT_MUTEX2_STREAM_EOF,
> > +	CMDQ_EVENT_MUTEX3_STREAM_EOF,
> > +	CMDQ_EVENT_MUTEX4_STREAM_EOF,
> > +	/* Display underrun events */
> > +	CMDQ_EVENT_DISP_RDMA0_UNDERRUN,
> > +	CMDQ_EVENT_DISP_RDMA1_UNDERRUN,
> > +	CMDQ_EVENT_DISP_RDMA2_UNDERRUN,
> > +	/* Keep this at the end */
> > +	CMDQ_MAX_EVENT,
> > +};
> > +
> > +struct cmdq_pkt;
> > +
> > +struct cmdq_base {
> > +	int	subsys;
> > +	u32	base;
> > +};
> > +
> > +struct cmdq_client {
> > +	struct mbox_client client;
> > +	struct mbox_chan *chan;
> > +};
> > +
> > +/**
> > + * cmdq_register_device() - register device which needs CMDQ
> > + * @dev:	device for CMDQ to access its registers
> > + *
> > + * Return: cmdq_base pointer or NULL for failed
> > + */
> > +struct cmdq_base *cmdq_register_device(struct device *dev);
> > +
> > +/**
> > + * cmdq_mbox_create() - create CMDQ mailbox client and channel
> > + * @dev:	device of CMDQ mailbox client
> > + * @index:	index of CMDQ mailbox channel
> > + *
> > + * Return: CMDQ mailbox client pointer
> > + */
> > +struct cmdq_client *cmdq_mbox_create(struct device *dev, int index);
> > +
> > +/**
> > + * cmdq_mbox_destroy() - destroy CMDQ mailbox client and channel
> > + * @client:	the CMDQ mailbox client
> > + */
> > +void cmdq_mbox_destroy(struct cmdq_client *client);
> > +
> > +/**
> > + * cmdq_pkt_create() - create a CMDQ packet
> > + * @pkt_ptr:	CMDQ packet pointer to retrieve cmdq_pkt
> > + *
> > + * Return: 0 for success; else the error code is returned
> > + */
> > +int cmdq_pkt_create(struct cmdq_pkt **pkt_ptr);
> > +
> > +/**
> > + * cmdq_pkt_destroy() - destroy the CMDQ packet
> > + * @pkt:	the CMDQ packet
> > + */
> > +void cmdq_pkt_destroy(struct cmdq_pkt *pkt);
> > +
> > +/**
> > + * cmdq_pkt_write() - append write command to the CMDQ packet
> > + * @pkt:	the CMDQ packet
> > + * @value:	the specified target register value
> > + * @base:	the CMDQ base
> > + * @offset:	register offset from module base
> > + *
> > + * Return: 0 for success; else the error code is returned
> > + */
> > +int cmdq_pkt_write(struct cmdq_pkt *pkt, u32 value,
> > +		   struct cmdq_base *base, u32 offset);
> > +
> > +/**
> > + * cmdq_pkt_write_mask() - append write command with mask to the CMDQ packet
> > + * @pkt:	the CMDQ packet
> > + * @value:	the specified target register value
> > + * @base:	the CMDQ base
> > + * @offset:	register offset from module base
> > + * @mask:	the specified target register mask
> > + *
> > + * Return: 0 for success; else the error code is returned
> > + */
> > +int cmdq_pkt_write_mask(struct cmdq_pkt *pkt, u32 value,
> > +			struct cmdq_base *base, u32 offset, u32 mask);
> > +
> > +/**
> > + * cmdq_pkt_wfe() - append wait for event command to the CMDQ packet
> > + * @pkt:	the CMDQ packet
> > + * @event:	the desired event type to "wait and CLEAR"
> > + *
> > + * Return: 0 for success; else the error code is returned
> > + */
> > +int cmdq_pkt_wfe(struct cmdq_pkt *pkt, enum cmdq_event event);
> > +
> > +/**
> > + * cmdq_pkt_clear_event() - append clear event command to the CMDQ packet
> > + * @pkt:	the CMDQ packet
> > + * @event:	the desired event to be cleared
> > + *
> > + * Return: 0 for success; else the error code is returned
> > + */
> > +int cmdq_pkt_clear_event(struct cmdq_pkt *pkt, enum cmdq_event event);
> > +
> > +/**
> > + * cmdq_pkt_flush() - trigger CMDQ to execute the CMDQ packet
> > + * @client:	the CMDQ mailbox client
> > + * @pkt:	the CMDQ packet
> > + *
> > + * Return: 0 for success; else the error code is returned
> > + *
> > + * Trigger CMDQ to execute the CMDQ packet. Note that this is a
> > + * synchronous flush function. When the function returned, the recorded
> > + * commands have been done.
> > + */
> > +int cmdq_pkt_flush(struct cmdq_client *client, 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
> > + * @client:	the CMDQ mailbox client
> > + * @pkt:	the CMDQ packet
> > + * @cb:		called at the end of done packet
> > + * @data:	this data will pass back to cb
> > + *
> > + * Return: 0 for success; else the error code is returned
> > + *
> > + * Trigger CMDQ to asynchronously execute the CMDQ packet and call back
> > + * at the end of done packet. Note that this is an ASYNC function. When the
> > + * function returned, it may or may not be finished.
> > + */
> > +int cmdq_pkt_flush_async(struct cmdq_client *client, struct cmdq_pkt *pkt,
> > +			 cmdq_async_flush_cb cb, void *data);
> > +
> > +#endif	/* __MTK_CMDQ_H__ */
> 
>