Re: [PATCH v3 09/24] drm/rockchip: dw-mipi-dsi: only request HS clock when required

Sean Paul
2017-01-30T18:20:33Z

On Sun, Jan 29, 2017 at 01:24:29PM +0000, John Keeping wrote:
> Requesting the HS clock from the PHY before we initialize it causes an
> invalid signal to be sent out since the input clock is not yet
> configured. The PHY databook suggests only asserting this signal when
> performing HS transfers, so let's do that.
>

Reviewed-by: Sean Paul <seanpaul@chromium.org>

> Signed-off-by: John Keeping <john@metanate.com>
> Reviewed-by: Chris Zhong <zyw@rock-chips.com>
> ---
> v3:
> - Add Chris' Reviewed-by
> Unchanged in v2
>
> drivers/gpu/drm/rockchip/dw-mipi-dsi.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/rockchip/dw-mipi-dsi.c b/drivers/gpu/drm/rockchip/dw-mipi-dsi.c
> index 15d33c3c8cb7..03fc096fe1bd 100644
> --- a/drivers/gpu/drm/rockchip/dw-mipi-dsi.c
> +++ b/drivers/gpu/drm/rockchip/dw-mipi-dsi.c
> @@ -545,13 +545,15 @@ static int dw_mipi_dsi_host_detach(struct mipi_dsi_host *host,
> static void dw_mipi_message_config(struct dw_mipi_dsi *dsi,
> const struct mipi_dsi_msg *msg)
> {
> + bool lpm = msg->flags & MIPI_DSI_MSG_USE_LPM;
> u32 val = 0;
>
> if (msg->flags & MIPI_DSI_MSG_REQ_ACK)
> val |= EN_ACK_RQST;
> - if (msg->flags & MIPI_DSI_MSG_USE_LPM)
> + if (lpm)
> val |= CMD_MODE_ALL_LP;
>
> + dsi_write(dsi, DSI_LPCLK_CTRL, lpm ? 0 : PHY_TXREQUESTCLKHS);
> dsi_write(dsi, DSI_CMD_MODE_CFG, val);
> }
>
> @@ -693,6 +695,7 @@ static void dw_mipi_dsi_set_mode(struct dw_mipi_dsi *dsi,
> dsi_write(dsi, DSI_PWR_UP, RESET);
> dsi_write(dsi, DSI_MODE_CFG, ENABLE_VIDEO_MODE);
> dw_mipi_dsi_video_mode_config(dsi);
> + dsi_write(dsi, DSI_LPCLK_CTRL, PHY_TXREQUESTCLKHS);
> dsi_write(dsi, DSI_PWR_UP, POWERUP);
> }
> }
> @@ -710,7 +713,6 @@ static void dw_mipi_dsi_init(struct dw_mipi_dsi *dsi)
> | PHY_RSTZ | PHY_SHUTDOWNZ);
> dsi_write(dsi, DSI_CLKMGR_CFG, TO_CLK_DIVIDSION(10) |
> TX_ESC_CLK_DIVIDSION(7));
> - dsi_write(dsi, DSI_LPCLK_CTRL, PHY_TXREQUESTCLKHS);
> }
>
> static void dw_mipi_dsi_dpi_config(struct dw_mipi_dsi *dsi,
> --
> 2.11.0.197.gb556de5.dirty
>
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--
Sean Paul, Software Engineer, Google / Chromium OS