Re: [PATCH v11 11/12] drm/mediatek: update DSI sub driver flow for sending commands to panel

CK Hu
2017-01-19T03:22:45Z

Hi, YT:

one comment inline.

On Wed, 2017-01-11 at 14:51 +0800, YT Shen wrote:
> This patch update enable/disable flow of DSI module.
> Original flow works on there is a bridge chip: DSI -> bridge -> panel.
> In this case: DSI -> panel, the DSI sub driver flow should be updated.
> We need to initialize DSI first so that we can send commands to panel.
>
> Signed-off-by: shaoming chen <shaoming.chen@mediatek.com>
> Signed-off-by: YT Shen <yt.shen@mediatek.com>
> ---
> drivers/gpu/drm/mediatek/mtk_dsi.c | 89 +++++++++++++++++++++++++++++++-------
> 1 file changed, 74 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
> index 85f22d2..21392c4 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dsi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
> @@ -126,6 +126,10 @@
> #define CLK_HS_POST (0xff << 8)
> #define CLK_HS_EXIT (0xff << 16)
>
> +#define DSI_VM_CMD_CON 0x130
> +#define VM_CMD_EN BIT(0)
> +#define TS_VFP_EN BIT(5)
> +
> #define DSI_CMDQ0 0x180
> #define CONFIG (0xff << 0)
> #define SHORT_PACKET 0
> @@ -365,16 +369,23 @@ static void mtk_dsi_set_mode(struct mtk_dsi *dsi)
> u32 vid_mode = CMD_MODE;
>
> if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO) {
> - vid_mode = SYNC_PULSE_MODE;
> -
> - if ((dsi->mode_flags & MIPI_DSI_MODE_VIDEO_BURST) &&
> - !(dsi->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE))
> + if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO_BURST)
> vid_mode = BURST_MODE;
> + else if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE)
> + vid_mode = SYNC_PULSE_MODE;
> + else
> + vid_mode = SYNC_EVENT_MODE;
> }
>
> writel(vid_mode, dsi->regs + DSI_MODE_CTRL);
> }
>
> +static void mtk_dsi_set_vm_cmd(struct mtk_dsi *dsi)
> +{
> + mtk_dsi_mask(dsi, DSI_VM_CMD_CON, VM_CMD_EN, VM_CMD_EN);
> + mtk_dsi_mask(dsi, DSI_VM_CMD_CON, TS_VFP_EN, TS_VFP_EN);
> +}
> +
> static void mtk_dsi_ps_control_vact(struct mtk_dsi *dsi)
> {
> struct videomode *vm = &dsi->vm;
> @@ -512,6 +523,16 @@ static void mtk_dsi_start(struct mtk_dsi *dsi)
> writel(1, dsi->regs + DSI_START);
> }
>
> +static void mtk_dsi_stop(struct mtk_dsi *dsi)
> +{
> + writel(0, dsi->regs + DSI_START);
> +}
> +
> +static void mtk_dsi_set_cmd_mode(struct mtk_dsi *dsi)
> +{
> + writel(CMD_MODE, dsi->regs + DSI_MODE_CTRL);
> +}
> +
> static void mtk_dsi_set_interrupt_enable(struct mtk_dsi *dsi)
> {
> u32 inten = LPRX_RD_RDY_INT_FLAG | CMD_DONE_INT_FLAG | VM_DONE_INT_FLAG;
> @@ -570,6 +591,19 @@ static irqreturn_t mtk_dsi_irq(int irq, void *dev_id)
> return IRQ_HANDLED;
> }
>
> +static s32 mtk_dsi_switch_to_cmd_mode(struct mtk_dsi *dsi, u8 irq_flag, u32 t)
> +{
> + mtk_dsi_irq_data_clear(dsi, irq_flag);
> + mtk_dsi_set_cmd_mode(dsi);
> +
> + if (!mtk_dsi_wait_for_irq_done(dsi, irq_flag, t)) {
> + DRM_ERROR("failed to switch cmd mode\n");
> + return -ETIME;
> + } else {
> + return 0;
> + }
> +}
> +
> static void mtk_dsi_poweroff(struct mtk_dsi *dsi)
> {
> if (WARN_ON(dsi->refcount == 0))
> @@ -578,6 +612,17 @@ static void mtk_dsi_poweroff(struct mtk_dsi *dsi)
> if (--dsi->refcount != 0)
> return;
>
> + mtk_dsi_stop(dsi);
> + if (!mtk_dsi_switch_to_cmd_mode(dsi, VM_DONE_INT_FLAG, 500)) {
> + if (dsi->panel) {
> + if (drm_panel_unprepare(dsi->panel)) {

Why drm_panel_unprepare() in mtk_dsi_poweroff() but drm_panel_prepare()
in mtk_output_dsi_enable()? This asymmetric design would easily cause
some bugs.

Regards,
CK

> + DRM_ERROR("failed to unprepare the panel\n");
> + return;
> + }
> + }
> + }
> +
> + mtk_dsi_reset_engine(dsi);
> mtk_dsi_lane0_ulp_mode_enter(dsi);
> mtk_dsi_clk_ulp_mode_enter(dsi);
>
> @@ -596,13 +641,6 @@ static void mtk_output_dsi_enable(struct mtk_dsi *dsi)
> if (dsi->enabled)
> return;
>
> - if (dsi->panel) {
> - if (drm_panel_prepare(dsi->panel)) {
> - DRM_ERROR("failed to setup the panel\n");
> - return;
> - }
> - }
> -
> ret = mtk_dsi_poweron(dsi);
> if (ret < 0) {
> DRM_ERROR("failed to power on dsi\n");
> @@ -610,22 +648,43 @@ static void mtk_output_dsi_enable(struct mtk_dsi *dsi)
> }
>
> mtk_dsi_rxtx_control(dsi);
> + mtk_dsi_ps_control_vact(dsi);
> + mtk_dsi_set_vm_cmd(dsi);
> + mtk_dsi_config_vdo_timing(dsi);
> + mtk_dsi_set_interrupt_enable(dsi);
>
> mtk_dsi_clk_ulp_mode_leave(dsi);
> mtk_dsi_lane0_ulp_mode_leave(dsi);
> mtk_dsi_clk_hs_mode(dsi, 0);
> - mtk_dsi_set_mode(dsi);
>
> - mtk_dsi_ps_control_vact(dsi);
> - mtk_dsi_config_vdo_timing(dsi);
> - mtk_dsi_set_interrupt_enable(dsi);
> + if (dsi->panel) {
> + if (drm_panel_prepare(dsi->panel)) {
> + DRM_ERROR("failed to prepare the panel\n");
> + goto err_dsi_power_off;
> + }
> + }
>
> mtk_dsi_set_mode(dsi);
> mtk_dsi_clk_hs_mode(dsi, 1);
>
> mtk_dsi_start(dsi);
>
> + if (dsi->panel) {
> + if (drm_panel_enable(dsi->panel)) {
> + DRM_ERROR("failed to enable the panel\n");
> + goto err_panel_disable;
> + }
> + }
> +
> dsi->enabled = true;
> +
> + return;
> +err_panel_disable:
> + mtk_dsi_stop(dsi);
> + if (dsi->panel)
> + drm_panel_unprepare(dsi->panel);
> +err_dsi_power_off:
> + mtk_dsi_poweroff(dsi);
> }
>
> static void mtk_output_dsi_disable(struct mtk_dsi *dsi)