From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergey Suloev Subject: Re: [linux-sunxi] [PATCH 3/6] drm/sun4i: dsi: Add bridge support Date: Fri, 15 Mar 2019 18:20:07 +0300 Message-ID: References: <20190315130825.9005-1-jagan@amarulasolutions.com> <20190315130825.9005-4-jagan@amarulasolutions.com> <20190315134555.ekpywymjx3xqmdhf@flea> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============1881596124==" Return-path: In-Reply-To: <20190315134555.ekpywymjx3xqmdhf@flea> Content-Language: en-US List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Cc: devicetree@vger.kernel.org, Michael Trimarchi , Maxime Ripard , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Paul Kocialkowski , David Airlie , linux-sunxi@googlegroups.com, Rob Herring , jagan@amarulasolutions.com, Chen-Yu Tsai , linux-amarula@amarulasolutions.com, linux-arm-kernel@lists.infradead.org, Laurent Pinchart List-Id: devicetree@vger.kernel.org This is a multi-part message in MIME format. --===============1881596124== Content-Type: multipart/alternative; boundary="------------808BDAA5D27927159AF43C2B" Content-Language: en-US This is a multi-part message in MIME format. --------------808BDAA5D27927159AF43C2B Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Hi, Jagan, On 3/15/19 4:45 PM, Maxime Ripard wrote: > On Fri, Mar 15, 2019 at 02:32:55PM +0100, Paul Kocialkowski wrote: >> Hi, >> >> On Fri, 2019-03-15 at 18:38 +0530, Jagan Teki wrote: >>> Some display panels would come up with a non-DSI output which >>> can have an option to connect DSI interface by means of bridge >>> convertor. >>> >>> This DSI to non-DSI bridge convertor would require a bridge >>> driver that would communicate the DSI controller for bridge >>> functionalities. >>> >>> So, add support for bridge functionalities in Allwinner DSI >>> controller. >> See a few comments below. >> >>> Signed-off-by: Jagan Teki >>> --- >>> drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 65 +++++++++++++++++++------- >>> drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h | 1 + >>> 2 files changed, 49 insertions(+), 17 deletions(-) >>> >>> diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c >>> index 0960b96b62cc..64d74313b842 100644 >>> --- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c >>> +++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c >>> @@ -781,6 +781,9 @@ static void sun6i_dsi_encoder_enable(struct drm_encoder *encoder) >>> if (!IS_ERR(dsi->panel)) >>> drm_panel_prepare(dsi->panel); >>> >>> + if (!IS_ERR(dsi->bridge)) >>> + drm_bridge_pre_enable(dsi->bridge); >>> + >>> /* >>> * FIXME: This should be moved after the switch to HS mode. >>> * >>> @@ -796,6 +799,9 @@ static void sun6i_dsi_encoder_enable(struct drm_encoder *encoder) >>> if (!IS_ERR(dsi->panel)) >>> drm_panel_enable(dsi->panel); >>> >>> + if (!IS_ERR(dsi->bridge)) >>> + drm_bridge_enable(dsi->bridge); >>> + >>> sun6i_dsi_start(dsi, DSI_START_HSC); >>> >>> udelay(1000); >>> @@ -812,6 +818,9 @@ static void sun6i_dsi_encoder_disable(struct drm_encoder *encoder) >>> if (!IS_ERR(dsi->panel)) { >>> drm_panel_disable(dsi->panel); >>> drm_panel_unprepare(dsi->panel); >>> + } else if (!IS_ERR(dsi->bridge)) { >>> + drm_bridge_disable(dsi->bridge); >>> + drm_bridge_post_disable(dsi->bridge); >>> } >>> >>> phy_power_off(dsi->dphy); >>> @@ -973,11 +982,16 @@ static int sun6i_dsi_attach(struct mipi_dsi_host *host, >>> struct sun6i_dsi *dsi = host_to_sun6i_dsi(host); >>> >>> dsi->device = device; >>> - dsi->panel = of_drm_find_panel(device->dev.of_node); >>> - if (IS_ERR(dsi->panel)) >>> - return PTR_ERR(dsi->panel); >>> >>> - dev_info(host->dev, "Attached device %s\n", device->name); >>> + dsi->bridge = of_drm_find_bridge(device->dev.of_node); >>> + if (!dsi->bridge) { >> You are using IS_ERR to check that the bridge is alive in the changes >> above, but switch to checking that it's non-NULL at this point. >> >> Are both guaranteed to be interchangeable? > They aren't. Any ERR_PTR will be !NULL > >>> + dsi->panel = of_drm_find_panel(device->dev.of_node); >>> + if (IS_ERR(dsi->panel)) >>> + return PTR_ERR(dsi->panel); >>> + } >> You should probably use drm_of_find_panel_or_bridge instead of >> duplicating the logic here. > Or we can even use the drm_panel_bridge_add to simplify things. this approach is implemented by E.Anholt in VC4 dsi driver and it looks nice. > > Maxime > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel --------------808BDAA5D27927159AF43C2B Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: 7bit

Hi, Jagan,

On 3/15/19 4:45 PM, Maxime Ripard wrote:
On Fri, Mar 15, 2019 at 02:32:55PM +0100, Paul Kocialkowski wrote:

Hi,

On Fri, 2019-03-15 at 18:38 +0530, Jagan Teki wrote:

Some display panels would come up with a non-DSI output which
can have an option to connect DSI interface by means of bridge
convertor.

This DSI to non-DSI bridge convertor would require a bridge
driver that would communicate the DSI controller for bridge
functionalities.

So, add support for bridge functionalities in Allwinner DSI
controller.

See a few comments below.


Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
---
 drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 65 +++++++++++++++++++-------
 drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h |  1 +
 2 files changed, 49 insertions(+), 17 deletions(-)

diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
index 0960b96b62cc..64d74313b842 100644
--- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
+++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
@@ -781,6 +781,9 @@ static void sun6i_dsi_encoder_enable(struct drm_encoder *encoder)
 	if (!IS_ERR(dsi->panel))
 		drm_panel_prepare(dsi->panel);
 
+	if (!IS_ERR(dsi->bridge))
+		drm_bridge_pre_enable(dsi->bridge);
+
 	/*
 	 * FIXME: This should be moved after the switch to HS mode.
 	 *
@@ -796,6 +799,9 @@ static void sun6i_dsi_encoder_enable(struct drm_encoder *encoder)
 	if (!IS_ERR(dsi->panel))
 		drm_panel_enable(dsi->panel);
 
+	if (!IS_ERR(dsi->bridge))
+		drm_bridge_enable(dsi->bridge);
+
 	sun6i_dsi_start(dsi, DSI_START_HSC);
 
 	udelay(1000);
@@ -812,6 +818,9 @@ static void sun6i_dsi_encoder_disable(struct drm_encoder *encoder)
 	if (!IS_ERR(dsi->panel)) {
 		drm_panel_disable(dsi->panel);
 		drm_panel_unprepare(dsi->panel);
+	} else if (!IS_ERR(dsi->bridge)) {
+		drm_bridge_disable(dsi->bridge);
+		drm_bridge_post_disable(dsi->bridge);
 	}
 
 	phy_power_off(dsi->dphy);
@@ -973,11 +982,16 @@ static int sun6i_dsi_attach(struct mipi_dsi_host *host,
 	struct sun6i_dsi *dsi = host_to_sun6i_dsi(host);
 
 	dsi->device = device;
-	dsi->panel = of_drm_find_panel(device->dev.of_node);
-	if (IS_ERR(dsi->panel))
-		return PTR_ERR(dsi->panel);
 
-	dev_info(host->dev, "Attached device %s\n", device->name);
+	dsi->bridge = of_drm_find_bridge(device->dev.of_node);
+	if (!dsi->bridge) {

You are using IS_ERR to check that the bridge is alive in the changes
above, but switch to checking that it's non-NULL at this point.

Are both guaranteed to be interchangeable?

They aren't. Any ERR_PTR will be !NULL


+		dsi->panel = of_drm_find_panel(device->dev.of_node);
+		if (IS_ERR(dsi->panel))
+			return PTR_ERR(dsi->panel);
+	}

You should probably use drm_of_find_panel_or_bridge instead of
duplicating the logic here.

Or we can even use the drm_panel_bridge_add to simplify things.

this approach is implemented by E.Anholt in VC4 dsi driver and it looks nice.


Maxime



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