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From:   Yannick Fertre <yannick.fertre@st.com>
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        Philippe Cornu <philippe.cornu@st.com>,
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Subject: [PATCH] drm/bridge/synopsys: dsi: add support for non-continuous HS clock
Date:   Wed, 1 Jul 2020 21:42:34 +0200
Message-ID: <20200701194234.18123-1-yannick.fertre@st.com>
MIME-Version: 1.0
Content-Type: text/plain
Sender: linux-kernel-owner@vger.kernel.org
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From: Antonio Borneo <antonio.borneo@st.com>

Current code enables the HS clock when video mode is started or to
send out a HS command, and disables the HS clock to send out a LP
command. This is not what DSI spec specify.

Enable HS clock either in command and in video mode.
Set automatic HS clock management for panels and devices that
support non-continuous HS clock.

Signed-off-by: Antonio Borneo <antonio.borneo@st.com>
---
 drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
index d580b2aa4ce9..979acaa90d00 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
@@ -365,7 +365,6 @@ static void dw_mipi_message_config(struct dw_mipi_dsi *dsi,
 	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);
 }
 
@@ -541,16 +540,22 @@ static void dw_mipi_dsi_video_mode_config(struct dw_mipi_dsi *dsi)
 static void dw_mipi_dsi_set_mode(struct dw_mipi_dsi *dsi,
 				 unsigned long mode_flags)
 {
+	u32 val;
+
 	dsi_write(dsi, DSI_PWR_UP, RESET);
 
 	if (mode_flags & MIPI_DSI_MODE_VIDEO) {
 		dsi_write(dsi, DSI_MODE_CFG, ENABLE_VIDEO_MODE);
 		dw_mipi_dsi_video_mode_config(dsi);
-		dsi_write(dsi, DSI_LPCLK_CTRL, PHY_TXREQUESTCLKHS);
 	} else {
 		dsi_write(dsi, DSI_MODE_CFG, ENABLE_CMD_MODE);
 	}
 
+	val = PHY_TXREQUESTCLKHS;
+	if (dsi->mode_flags & MIPI_DSI_CLOCK_NON_CONTINUOUS)
+		val |= AUTO_CLKLANE_CTRL;
+	dsi_write(dsi, DSI_LPCLK_CTRL, val);
+
 	dsi_write(dsi, DSI_PWR_UP, POWERUP);
 }
 
-- 
2.17.1