Re: [PATCH 4/5] drm/msm/dsi: implement 6G v2.0+ DSI command broadcast

[Archit Taneja <architt-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>]

On Monday 12 March 2018 06:53 PM, Sibi S wrote:
> From: Archit Taneja <architt@codeaurora.org>
> 

I'm a bit uncertain about using this patch in its current state.
Some reasons below.

> Add command broadcast support for DSI 6G v2.0+ controller
> on SDM845
> 
> Signed-off-by: Sibi S <sibis@codeaurora.org>
> ---
>   drivers/gpu/drm/msm/dsi/dsi.h         |  5 +++
>   drivers/gpu/drm/msm/dsi/dsi_cfg.c     | 14 +++++++-
>   drivers/gpu/drm/msm/dsi/dsi_host.c    | 62 ++++++++++++++++++++++++++++++--
>   drivers/gpu/drm/msm/dsi/dsi_manager.c | 66 +++++++++++++++++++++++++++++++++++
>   4 files changed, 143 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/dsi/dsi.h b/drivers/gpu/drm/msm/dsi/dsi.h
> index dfa049d..22342c30 100644
> --- a/drivers/gpu/drm/msm/dsi/dsi.h
> +++ b/drivers/gpu/drm/msm/dsi/dsi.h
> @@ -96,7 +96,9 @@ struct msm_dsi {
>   struct drm_connector *msm_dsi_manager_connector_init(u8 id);
>   struct drm_connector *msm_dsi_manager_ext_bridge_init(u8 id);
>   int msm_dsi_manager_cmd_xfer(int id, const struct mipi_dsi_msg *msg);
> +int msm_dsi_manager_cmd_xfer_6g_v2(int id, const struct mipi_dsi_msg *msg);
>   bool msm_dsi_manager_cmd_xfer_trigger(int id, u32 dma_base, u32 len);
> +bool msm_dsi_manager_cmd_xfer_trigger_6g_v2(int id, u32 dma_base, u32 len);
>   void msm_dsi_manager_attach_dsi_device(int id, u32 device_flags);
>   int msm_dsi_manager_register(struct msm_dsi *msm_dsi);
>   void msm_dsi_manager_unregister(struct msm_dsi *msm_dsi);
> @@ -152,6 +154,9 @@ static inline int msm_dsi_pll_set_usecase(struct msm_dsi_pll *pll,
>   struct msm_dsi_host;
>   int msm_dsi_host_xfer_prepare(struct mipi_dsi_host *host,
>   					const struct mipi_dsi_msg *msg);
> +int msm_dsi_host_xfer_prepare_6g_v2(struct mipi_dsi_host *host,
> +					const struct mipi_dsi_msg *msg,
> +					bool broadcast, bool master);
>   void msm_dsi_host_xfer_restore(struct mipi_dsi_host *host,
>   					const struct mipi_dsi_msg *msg);
>   int msm_dsi_host_cmd_tx(struct mipi_dsi_host *host,
> diff --git a/drivers/gpu/drm/msm/dsi/dsi_cfg.c b/drivers/gpu/drm/msm/dsi/dsi_cfg.c
> index dc51aaa..dcdfb1b 100644
> --- a/drivers/gpu/drm/msm/dsi/dsi_cfg.c
> +++ b/drivers/gpu/drm/msm/dsi/dsi_cfg.c
> @@ -157,6 +157,18 @@
>   	.dma_base_get = dsi_dma_base_get_6g,
>   	.calc_clk_rate = dsi_calc_clk_rate_6g,
>   };
> +
> +const static struct msm_dsi_host_cfg_ops msm_dsi_6g_v2_host_ops = {
> +	.link_clk_enable = dsi_link_clk_enable_6g,
> +	.link_clk_disable = dsi_link_clk_disable_6g,
> +	.clk_init_ver = dsi_clk_init_6g_v2,
> +	.tx_buf_alloc = dsi_tx_buf_alloc_6g,
> +	.tx_buf_get = dsi_tx_buf_get_6g,
> +	.tx_buf_put = dsi_tx_buf_put_6g,
> +	.dma_base_get = dsi_dma_base_get_6g,
> +	.calc_clk_rate = dsi_calc_clk_rate_6g,
> +};
> +
>   static const struct msm_dsi_cfg_handler dsi_cfg_handlers[] = {
>   	{MSM_DSI_VER_MAJOR_V2, MSM_DSI_V2_VER_MINOR_8064,
>   		&apq8064_dsi_cfg, &msm_dsi_v2_host_ops},
> @@ -175,7 +187,7 @@
>   	{MSM_DSI_VER_MAJOR_6G, MSM_DSI_6G_VER_MINOR_V1_4_1,
>   		&msm8996_dsi_cfg, &msm_dsi_6g_host_ops},
>   	{MSM_DSI_VER_MAJOR_6G, MSM_DSI_6G_VER_MINOR_V2_2_1,
> -		&sdm845_dsi_cfg, &msm_dsi_6g_host_ops},
> +		&sdm845_dsi_cfg, &msm_dsi_6g_v2_host_ops},
>   };
>   
>   const struct msm_dsi_cfg_handler *msm_dsi_cfg_get(u32 major, u32 minor)
> diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c
> index b755b69..bd61cad 100644
> --- a/drivers/gpu/drm/msm/dsi/dsi_host.c
> +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
> @@ -1251,9 +1251,14 @@ static int dsi_cmd_dma_tx(struct msm_dsi_host *msm_host, int len)
>   	reinit_completion(&msm_host->dma_comp);
>   
>   	dsi_wait4video_eng_busy(msm_host);
> +	if ((cfg_hnd->major == MSM_DSI_VER_MAJOR_6G) &&
> +			(cfg_hnd->minor < MSM_DSI_6G_VER_MINOR_V2_2_1))
> +		triggered = msm_dsi_manager_cmd_xfer_trigger(msm_host->id,
> +								dma_base, len);
> +	else
> +		triggered = msm_dsi_manager_cmd_xfer_trigger_6g_v2(
> +						  msm_host->id, dma_base, len);
>   
> -	triggered = msm_dsi_manager_cmd_xfer_trigger(
> -						msm_host->id, dma_base, len);
>   	if (triggered) {
>   		ret = wait_for_completion_timeout(&msm_host->dma_comp,
>   					msecs_to_jiffies(200));
> @@ -1602,13 +1607,21 @@ static ssize_t dsi_host_transfer(struct mipi_dsi_host *host,
>   					const struct mipi_dsi_msg *msg)
>   {
>   	struct msm_dsi_host *msm_host = to_msm_dsi_host(host);
> +	const struct msm_dsi_cfg_handler *cfg_hnd = msm_host->cfg_hnd;
>   	int ret;
>   
>   	if (!msg || !msm_host->power_on)
>   		return -EINVAL;
>   
>   	mutex_lock(&msm_host->cmd_mutex);
> -	ret = msm_dsi_manager_cmd_xfer(msm_host->id, msg);
> +
> +	if (((cfg_hnd->major == MSM_DSI_VER_MAJOR_6G) &&
> +			(cfg_hnd->minor < MSM_DSI_6G_VER_MINOR_V2_2_1)) ||
> +			(cfg_hnd->major == MSM_DSI_VER_MAJOR_V2))
> +		ret = msm_dsi_manager_cmd_xfer(msm_host->id, msg);
> +	else
> +		ret = msm_dsi_manager_cmd_xfer_6g_v2(msm_host->id, msg);
> +
>   	mutex_unlock(&msm_host->cmd_mutex);
>   
>   	return ret;
> @@ -1992,6 +2005,49 @@ int msm_dsi_host_xfer_prepare(struct mipi_dsi_host *host,
>   	return 0;
>   }
>   
> +static void dsi_host_prepare_broadcast_6g_v2(struct msm_dsi_host *msm_host,
> +					     bool broadcast, bool master)
> +{
> +	u32 val = dsi_read(msm_host, REG_DSI_CMD_DMA_CTRL);
> +
> +	if (broadcast)
> +		val |= BIT(31);
> +	else
> +		val &= ~BIT(31);
> +
> +	if (master)
> +		val |= BIT(30);
> +	else
> +		val &= ~BIT(30);
> +
> +	dsi_write(msm_host, REG_DSI_CMD_DMA_CTRL, val);
> + > +
> +int msm_dsi_host_xfer_prepare_6g_v2(struct mipi_dsi_host *host,
> +				    const struct mipi_dsi_msg *msg,
> +				    bool broadcast, bool master)
> +{
> +	struct msm_dsi_host *msm_host = to_msm_dsi_host(host);
> +
> +	/* TODO: vote for bus bandwidth */
> +
> +	if (!(msg->flags & MIPI_DSI_MSG_USE_LPM))
> +		dsi_set_tx_power_mode(0, msm_host);
> +
> +	dsi_host_prepare_broadcast_6g_v2(msm_host, broadcast, master);
> +
> +	msm_host->dma_cmd_ctrl_restore = dsi_read(msm_host, REG_DSI_CTRL);
> +	dsi_write(msm_host, REG_DSI_CTRL,
> +		msm_host->dma_cmd_ctrl_restore |
> +		DSI_CTRL_CMD_MODE_EN |
> +		DSI_CTRL_ENABLE);
> +
> +	if ((broadcast && master) || !broadcast)
> +		dsi_intr_ctrl(msm_host, DSI_IRQ_MASK_CMD_DMA_DONE, 1);
> +
> +	return 0;
> +}

This part above (i.e, the prepare for 6G v2.0+) looks okay.

> +
>   void msm_dsi_host_xfer_restore(struct mipi_dsi_host *host,
>   				const struct mipi_dsi_msg *msg)
>   {
> diff --git a/drivers/gpu/drm/msm/dsi/dsi_manager.c b/drivers/gpu/drm/msm/dsi/dsi_manager.c
> index 4cb1cb6..393e3ff 100644
> --- a/drivers/gpu/drm/msm/dsi/dsi_manager.c
> +++ b/drivers/gpu/drm/msm/dsi/dsi_manager.c
> @@ -812,6 +812,56 @@ int msm_dsi_manager_cmd_xfer(int id, const struct mipi_dsi_msg *msg)
>   	return ret;
>   }
>   
> +int msm_dsi_manager_cmd_xfer_6g_v2(int id, const struct mipi_dsi_msg *msg)
> +{
> +	struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
> +	struct msm_dsi *msm_dsi0 = dsi_mgr_get_dsi(DSI_0);
> +	struct mipi_dsi_host *host = msm_dsi->host;
> +	bool is_read = (msg->rx_buf && msg->rx_len);
> +	bool need_sync = (IS_SYNC_NEEDED() && !is_read);
> +	int ret;
> +
> +	if (!msg->tx_buf || !msg->tx_len)
> +		return 0;
> +
> +	if (need_sync && (id == DSI_0))
> +		return is_read ? msg->rx_len : msg->tx_len;
> +
> +	if (need_sync && msm_dsi0) {
> +		ret = msm_dsi_host_xfer_prepare_6g_v2(msm_dsi0->host, msg,
> +						      true, true);
> +		if (ret) {
> +			pr_err("%s: failed to prepare non-trigger host, %d\n",
> +				__func__, ret);
> +			return ret;
> +		}
> +	}
> +
> +	ret = msm_dsi_host_xfer_prepare_6g_v2(msm_dsi->host, msg,
> +					      need_sync ? true : false,
> +					      false);
> +	if (ret) {
> +		pr_err("%s: failed to prepare host, %d\n",
> +			__func__, ret);
> +		return ret;
> +	}
> +
> +	if (need_sync && msm_dsi0) {
> +		ret = is_read ? msm_dsi_host_cmd_rx(msm_dsi0->host, msg) :
> +				msm_dsi_host_cmd_tx(msm_dsi0->host, msg);
> +	} else {
> +		ret = is_read ? msm_dsi_host_cmd_rx(msm_dsi->host, msg) :
> +				msm_dsi_host_cmd_tx(msm_dsi->host, msg);
> +	}
> +
> +	msm_dsi_host_xfer_restore(host, msg);
> +
> +	if (need_sync && msm_dsi0)
> +		msm_dsi_host_xfer_restore(msm_dsi0->host, msg);
> +
> +	return ret;
> +}

I think the func above has problems, I'd mostly copied it from the
original msm_dsi_manager_cmd_xfer func. We don't know if the 'need_sync'
feature is something that's even needed for SDM845. Also, we have
assumed here msm_dsi0 will always be the clock master, we might have
to make it flexible to work with either DSI being the clock master.

> +
>   bool msm_dsi_manager_cmd_xfer_trigger(int id, u32 dma_base, u32 len)
>   {
>   	struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
> @@ -829,6 +879,22 @@ bool msm_dsi_manager_cmd_xfer_trigger(int id, u32 dma_base, u32 len)
>   	return true;
>   }
>   
> +bool msm_dsi_manager_cmd_xfer_trigger_6g_v2(int id, u32 dma_base, u32 len)
> +{
> +	struct msm_dsi *msm_dsi1 = dsi_mgr_get_dsi(DSI_1);
> +	struct msm_dsi *msm_dsi0 = dsi_mgr_get_dsi(DSI_0);
> +
> +	if (IS_SYNC_NEEDED() && (id == DSI_1))
> +		return false;
> +
> +	msm_dsi_host_cmd_xfer_commit(msm_dsi1->host, dma_base, len);
> +
> +	if (IS_SYNC_NEEDED() && msm_dsi0)
> +		msm_dsi_host_cmd_xfer_commit(msm_dsi0->host, dma_base, len);
> +

This again is something I'd hacked to get the display running, we can't
assume that msm_dsi0 is going to be the clock master.

Thanks,
Archit

> +	return true;
> +}
> +
>   void msm_dsi_manager_attach_dsi_device(int id, u32 device_flags)
>   {
>   	struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
> 
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