From mboxrd@z Thu Jan 1 00:00:00 1970 From: Neil Armstrong Subject: Re: [PATCH 1/2] drm/bridge/synopsys: dw-hdmi: Add an option to suppress loading CEC driver Date: Mon, 25 Mar 2019 09:33:11 +0100 Message-ID: <5C989247.6090709@baylibre.com> References: <20190324212144.3652-1-jernej.skrabec@siol.net> <20190324212144.3652-2-jernej.skrabec@siol.net> <20190325013531.GB4540@pendragon.ideasonboard.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20190325013531.GB4540@pendragon.ideasonboard.com> Sender: linux-kernel-owner@vger.kernel.org To: Laurent Pinchart , Jernej Skrabec Cc: maxime.ripard@bootlin.com, airlied@linux.ie, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, wens@csie.org, linux-arm-kernel@lists.infradead.org List-Id: dri-devel@lists.freedesktop.org Le 25/03/2019 02:35, Laurent Pinchart a écrit : > Hi Jernej, > > Thank you for the patch. > > On Sun, Mar 24, 2019 at 10:21:42PM +0100, Jernej Skrabec wrote: >> DW HDMI controller on some Allwinner SoCs has support for CEC, but due >> to additional logic put between CEC controller and pins, it doesn't work >> correctly, at least not with a lot of instrusive changes. Fortunately, >> it's still possible to bitbang protocol. >> >> For such cases, add a platform option to suppress loading CEC driver. If >> DW HDMI CEC driver would be loaded, it wouldn't work anyway and only >> cause a confusion with multiple /dev entries. >> >> Signed-off-by: Jernej Skrabec >> --- >> drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 2 +- >> include/drm/bridge/dw_hdmi.h | 2 ++ >> 2 files changed, 3 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c >> index a63e5f0dae56..fdda26f8b056 100644 >> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c >> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c >> @@ -2634,7 +2634,7 @@ __dw_hdmi_probe(struct platform_device *pdev, >> hdmi->audio = platform_device_register_full(&pdevinfo); >> } >> >> - if (config0 & HDMI_CONFIG0_CEC) { >> + if (!plat_data->is_cec_unusable && (config0 & HDMI_CONFIG0_CEC)) { >> cec.hdmi = hdmi; >> cec.ops = &dw_hdmi_cec_ops; >> cec.irq = irq; >> diff --git a/include/drm/bridge/dw_hdmi.h b/include/drm/bridge/dw_hdmi.h >> index 66e70770cce5..764b8bcfa62c 100644 >> --- a/include/drm/bridge/dw_hdmi.h >> +++ b/include/drm/bridge/dw_hdmi.h >> @@ -144,6 +144,8 @@ struct dw_hdmi_plat_data { >> int (*configure_phy)(struct dw_hdmi *hdmi, >> const struct dw_hdmi_plat_data *pdata, >> unsigned long mpixelclock); >> + >> + unsigned int is_cec_unusable : 1; > > Strictly speaking your CEC controller isn't unusable, it's just a bit > difficult to use it according to your commit message. Would disable_cec > be a more appropriate field name ? Actually, it would be useful to have in for Amlogic SoCs also, the dw-hdmi is configured with the CEC engine, but isn't connected to an external I/O. And we have easy way to disable it unless disabling the DW-HDMI CEC driver... With a more appropriate name, Reviewed-by: Neil Armstrong > And how difficult would it be to > support the hardware CEC controller, would that result in changes that > could be useful to other vendors too ? > >> }; >> >> struct dw_hdmi *dw_hdmi_probe(struct platform_device *pdev, >