From patchwork Tue May 25 07:30:28 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Rajeev Nandan X-Patchwork-Id: 448295 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.9 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNWANTED_LANGUAGE_BODY, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 55AD0C47084 for ; Tue, 25 May 2021 07:31:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 34C916140B for ; Tue, 25 May 2021 07:31:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231689AbhEYHc6 (ORCPT ); Tue, 25 May 2021 03:32:58 -0400 Received: from alexa-out.qualcomm.com ([129.46.98.28]:8271 "EHLO alexa-out.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231671AbhEYHc6 (ORCPT ); Tue, 25 May 2021 03:32:58 -0400 Received: from ironmsg08-lv.qualcomm.com ([10.47.202.152]) by alexa-out.qualcomm.com with ESMTP; 25 May 2021 00:31:29 -0700 X-QCInternal: smtphost Received: from ironmsg01-blr.qualcomm.com ([10.86.208.130]) by ironmsg08-lv.qualcomm.com with ESMTP/TLS/AES256-SHA; 25 May 2021 00:31:27 -0700 X-QCInternal: smtphost Received: from rajeevny-linux.qualcomm.com ([10.204.66.121]) by ironmsg01-blr.qualcomm.com with ESMTP; 25 May 2021 13:00:37 +0530 Received: by rajeevny-linux.qualcomm.com (Postfix, from userid 2363605) id 542A02145A; Tue, 25 May 2021 13:00:36 +0530 (IST) From: Rajeev Nandan To: y@qualcomm.com, dri-devel@lists.freedesktop.org, linux-arm-msm@vger.kernel.org, freedreno@lists.freedesktop.org, devicetree@vger.kernel.org Cc: Rajeev Nandan , linux-kernel@vger.kernel.org, thierry.reding@gmail.com, sam@ravnborg.org, robdclark@gmail.com, dianders@chromium.org, lyude@redhat.com, jani.nikula@intel.com, robh@kernel.org, laurent.pinchart@ideasonboard.com, a.hajda@samsung.com, daniel.thompson@linaro.org, hoegsberg@chromium.org, abhinavk@codeaurora.org, seanpaul@chromium.org, kalyan_t@codeaurora.org, mkrishn@codeaurora.org Subject: [v4 1/4] drm/panel-simple: Add basic DPCD backlight support Date: Tue, 25 May 2021 13:00:28 +0530 Message-Id: <1621927831-29471-2-git-send-email-rajeevny@codeaurora.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1621927831-29471-1-git-send-email-rajeevny@codeaurora.org> References: <1621927831-29471-1-git-send-email-rajeevny@codeaurora.org> Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org Add basic support of panel backlight control over eDP aux channel using VESA's standard backlight control interface. Signed-off-by: Rajeev Nandan --- This patch depends on [1] (drm/panel: panel-simple: Stash DP AUX bus; allow using it for DDC) Changes in v4: - New [1] https://lore.kernel.org/dri-devel/20210524165920.v8.7.I18e60221f6d048d14d6c50a770b15f356fa75092@changeid/ drivers/gpu/drm/panel/panel-simple.c | 99 ++++++++++++++++++++++++++++++++++-- 1 file changed, 96 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c index b09be6e..f9e4e60 100644 --- a/drivers/gpu/drm/panel/panel-simple.c +++ b/drivers/gpu/drm/panel/panel-simple.c @@ -21,6 +21,7 @@ * DEALINGS IN THE SOFTWARE. */ +#include #include #include #include @@ -171,6 +172,19 @@ struct panel_desc { /** @connector_type: LVDS, eDP, DSI, DPI, etc. */ int connector_type; + + /** + * @uses_dpcd_backlight: Panel supports eDP dpcd backlight control. + * + * Set true, if the panel supports backlight control over eDP AUX channel + * using DPCD registers as per VESA's standard. + */ + bool uses_dpcd_backlight; +}; + +struct edp_backlight { + struct backlight_device *dev; + struct drm_edp_backlight_info info; }; struct panel_simple { @@ -194,6 +208,8 @@ struct panel_simple { struct edid *edid; + struct edp_backlight *edp_bl; + struct drm_display_mode override_mode; enum drm_panel_orientation orientation; @@ -330,10 +346,14 @@ static void panel_simple_wait(ktime_t start_ktime, unsigned int min_ms) static int panel_simple_disable(struct drm_panel *panel) { struct panel_simple *p = to_panel_simple(panel); + struct edp_backlight *bl = p->edp_bl; if (!p->enabled) return 0; + if (p->desc->uses_dpcd_backlight && bl) + drm_edp_backlight_disable(p->aux, &bl->info); + if (p->desc->delay.disable) msleep(p->desc->delay.disable); @@ -496,6 +516,7 @@ static int panel_simple_prepare(struct drm_panel *panel) static int panel_simple_enable(struct drm_panel *panel) { struct panel_simple *p = to_panel_simple(panel); + struct edp_backlight *bl = p->edp_bl; if (p->enabled) return 0; @@ -505,6 +526,10 @@ static int panel_simple_enable(struct drm_panel *panel) panel_simple_wait(p->prepared_time, p->desc->delay.prepare_to_enable); + if (p->desc->uses_dpcd_backlight && bl) + drm_edp_backlight_enable(p->aux, &bl->info, + bl->dev->props.brightness); + p->enabled = true; return 0; @@ -565,6 +590,59 @@ static const struct drm_panel_funcs panel_simple_funcs = { .get_timings = panel_simple_get_timings, }; +static int edp_backlight_update_status(struct backlight_device *bd) +{ + struct panel_simple *p = bl_get_data(bd); + struct edp_backlight *bl = p->edp_bl; + + if (!p->enabled) + return 0; + + return drm_edp_backlight_set_level(p->aux, &bl->info, bd->props.brightness); +} + +static const struct backlight_ops edp_backlight_ops = { + .update_status = edp_backlight_update_status, +}; + +static int edp_backlight_register(struct device *dev, struct panel_simple *panel) +{ + struct edp_backlight *bl; + struct backlight_properties props = { 0 }; + u16 current_level; + u8 current_mode; + u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE]; + int ret; + + bl = devm_kzalloc(dev, sizeof(*bl), GFP_KERNEL); + if (!bl) + return -ENOMEM; + + ret = drm_dp_dpcd_read(panel->aux, DP_EDP_DPCD_REV, edp_dpcd, + EDP_DISPLAY_CTL_CAP_SIZE); + if (ret < 0) + return ret; + + ret = drm_edp_backlight_init(panel->aux, &bl->info, 0, edp_dpcd, + ¤t_level, ¤t_mode); + if (ret < 0) + return ret; + + props.type = BACKLIGHT_RAW; + props.brightness = current_level; + props.max_brightness = bl->info.max; + + bl->dev = devm_backlight_device_register(dev, "edp_backlight", + dev, panel, + &edp_backlight_ops, &props); + if (IS_ERR(bl->dev)) + return PTR_ERR(bl->dev); + + panel->edp_bl = bl; + + return 0; +} + static struct panel_desc panel_dpi; static int panel_dpi_probe(struct device *dev, @@ -796,9 +874,24 @@ static int panel_simple_probe(struct device *dev, const struct panel_desc *desc, drm_panel_init(&panel->base, dev, &panel_simple_funcs, connector_type); - err = drm_panel_of_backlight(&panel->base); - if (err) - goto disable_pm_runtime; + if (panel->desc->uses_dpcd_backlight) { + if (!panel->aux) { + dev_err(dev, "edp backlight needs DP aux\n"); + err = -EINVAL; + goto disable_pm_runtime; + } + + err = edp_backlight_register(dev, panel); + if (err) { + dev_err(dev, "failed to register edp backlight %d\n", err); + goto disable_pm_runtime; + } + + } else { + err = drm_panel_of_backlight(&panel->base); + if (err) + goto disable_pm_runtime; + } drm_panel_add(&panel->base);