From mboxrd@z Thu Jan 1 00:00:00 1970 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=-13.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 D793BC4361B for ; Fri, 11 Dec 2020 15:01:31 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7CE5D206B2 for ; Fri, 11 Dec 2020 15:01:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7CE5D206B2 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id B9C986E03A; Fri, 11 Dec 2020 15:01:30 +0000 (UTC) Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by gabe.freedesktop.org (Postfix) with ESMTPS id 799916E03A; Fri, 11 Dec 2020 15:01:29 +0000 (UTC) IronPort-SDR: 8KCiMq56Rm4aCGlcTAwoehNTRWZV6iU8gJ8G+XLeSjQfeT38Mypjj1E81SAOzmg3u8qEyVmP23 HL8i6+pj09CQ== X-IronPort-AV: E=McAfee;i="6000,8403,9831"; a="153674120" X-IronPort-AV: E=Sophos;i="5.78,411,1599548400"; d="scan'208";a="153674120" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Dec 2020 07:01:28 -0800 IronPort-SDR: pRbDdXN8m2edHgF3xIZp4288PRtPIverv+tcqnxNT3B2zQijrcsuzWZjZmLfoURSAnseK9X107 ObzM+oqXoN8g== X-IronPort-AV: E=Sophos;i="5.78,411,1599548400"; d="scan'208";a="409268204" Received: from dkreft-mobl1.ger.corp.intel.com (HELO localhost) ([10.249.158.206]) by orsmga001-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Dec 2020 07:01:18 -0800 From: Jani Nikula To: Lyude Paul , dri-devel@lists.freedesktop.org, nouveau@lists.freedesktop.org, intel-gfx@lists.freedesktop.org In-Reply-To: <20201210012143.729402-5-lyude@redhat.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo References: <20201210012143.729402-1-lyude@redhat.com> <20201210012143.729402-5-lyude@redhat.com> Date: Fri, 11 Dec 2020 17:01:15 +0200 Message-ID: <87a6uk75fo.fsf@intel.com> MIME-Version: 1.0 Subject: Re: [Intel-gfx] [RFC 4/5] drm/dp: Extract i915's eDP backlight code into DRM helpers X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: greg.depoire@gmail.com, Lucas De Marchi , open list , Maxime Ripard , David Airlie , Sean Paul , Thomas Zimmermann , Aaron Ma Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Wed, 09 Dec 2020, Lyude Paul wrote: > Since we're about to implement eDP backlight support in nouveau using the > standard protocol from VESA, we might as well just take the code that's > already written for this and move it into a set of shared DRM helpers. > > Note that these helpers are intended to handle DPCD related backlight > control bits such as setting the brightness level over AUX, probing the > backlight's TCON, enabling/disabling the backlight over AUX if supported, > etc. Any PWM-related portions of backlight control are explicitly left up > to the driver, as these will vary from platform to platform. > > The only exception to this is the calculation of the PWM frequency > pre-divider value. This is because the only platform-specific information > required for this is the PWM frequency of the panel, which the driver is > expected to provide if available. The actual algorithm for calculating this > value is standard and is defined in the eDP specification from VESA. > > Note that these helpers do not yet implement the full range of features > the VESA backlight interface provides, and only provide the following > functionality (all of which was already present in i915's DPCD backlight > support): > > * Basic control of brightness levels > * Basic probing of backlight capabilities > * Helpers for enabling and disabling the backlight Overall I like where this is going. Again, not a full review yet, just a few notes below. > > Signed-off-by: Lyude Paul > Cc: Jani Nikula > Cc: Dave Airlie > Cc: greg.depoire@gmail.com > --- > drivers/gpu/drm/drm_dp_helper.c | 332 ++++++++++++++++++ > .../drm/i915/display/intel_display_types.h | 5 +- > .../drm/i915/display/intel_dp_aux_backlight.c | 304 ++-------------- > include/drm/drm_dp_helper.h | 48 +++ > 4 files changed, 419 insertions(+), 270 deletions(-) > > diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c > index 5bd0934004e3..06fdddf44e54 100644 > --- a/drivers/gpu/drm/drm_dp_helper.c > +++ b/drivers/gpu/drm/drm_dp_helper.c > @@ -2596,3 +2596,335 @@ void drm_dp_vsc_sdp_log(const char *level, struct device *dev, > #undef DP_SDP_LOG > } > EXPORT_SYMBOL(drm_dp_vsc_sdp_log); > + > +/** > + * drm_edp_backlight_set_level() - Set the backlight level of an eDP panel via AUX > + * @aux: The DP AUX channel to use > + * @bl: Backlight capability info from drm_edp_backlight_init() > + * @level: The brightness level to set > + * > + * Sets the brightness level of an eDP panel's backlight. Note that the panel's backlight must > + * already have been enabled by the driver by calling drm_edp_backlight_enable(). > + * > + * Returns: %0 on success, negative error code on failure > + */ > +int drm_edp_backlight_set_level(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl, > + u16 level) I think I'd go for s/backlight/brightness/g function naming thoughout, to account for OLED. "Backlight" unnecessarily underlines the technology. > +{ > + int ret; > + u8 buf[2] = { 0 }; > + > + if (bl->lsb_reg_used) { > + buf[0] = (level & 0xFF00) >> 8; > + buf[1] = (level & 0x00FF); > + } else { > + buf[0] = level; > + } > + > + ret = drm_dp_dpcd_write(aux, DP_EDP_BACKLIGHT_BRIGHTNESS_MSB, buf, sizeof(buf)); > + if (ret != sizeof(buf)) { > + DRM_ERROR("%s: Failed to write aux backlight level: %d\n", aux->name, ret); I'd really like to have a way to get from struct drm_dp_aux to struct drm_device to retain the device specific logging here. It'd be useful in the lower level dpcd access functions too. > + return ret < 0 ? ret : -EIO; > + } > + > + return 0; > +} > +EXPORT_SYMBOL(drm_edp_backlight_set_level); > + > +static int > +drm_edp_backlight_set_enable(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl, > + bool enable) > +{ > + int ret; > + u8 buf; > + > + /* The panel uses something other then DPCD for enabling it's backlight */ > + if (!bl->aux_enable) > + return 0; > + > + ret = drm_dp_dpcd_readb(aux, DP_EDP_DISPLAY_CONTROL_REGISTER, &buf); > + if (ret != 1) { > + DRM_ERROR("%s: Failed to read eDP display control register: %d\n", aux->name, ret); > + return ret < 0 ? ret : -EIO; > + } > + if (enable) > + buf |= DP_EDP_BACKLIGHT_ENABLE; > + else > + buf &= ~DP_EDP_BACKLIGHT_ENABLE; > + > + ret = drm_dp_dpcd_writeb(aux, DP_EDP_DISPLAY_CONTROL_REGISTER, buf); > + if (ret != 1) { > + DRM_ERROR("%s: Failed to write eDP display control register: %d\n", aux->name, ret); > + return ret < 0 ? ret : -EIO; > + } > + > + return 0; > +} > + > +/** > + * drm_edp_backlight_enable() - Enable an eDP panel's backlight using DPCD > + * @aux: The DP AUX channel to use > + * @bl: Backlight capability info from drm_edp_backlight_init() > + * @level: The initial backlight level to set via AUX, if there is one > + * > + * This function handles enabling DPCD backlight controls on a panel over DPCD, while additionally > + * restoring any important backlight state such as the given backlight level, the brightness byte > + * count, backlight frequency, etc. > + * > + * Note that certain panels, while supporting brightness level controls over DPCD, may not support > + * having their backlights enabled via the standard %DP_EDP_DISPLAY_CONTROL_REGISTER. On such panels > + * &drm_edp_backlight_info.aux_enable will be set to %false, this function will skip the step of > + * programming the %DP_EDP_DISPLAY_CONTROL_REGISTER, and the driver must perform the required > + * implementation specific step for enabling the backlight after calling this function. > + * > + * Returns: %0 on success, negative error code on failure. > + */ > +int drm_edp_backlight_enable(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl, > + const u16 level) > +{ > + int ret; > + u8 dpcd_buf, new_dpcd_buf; > + > + ret = drm_dp_dpcd_readb(aux, DP_EDP_BACKLIGHT_MODE_SET_REGISTER, &dpcd_buf); > + if (ret != 1) { > + DRM_DEBUG_KMS("%s: Failed to read backlight mode: %d\n", aux->name, ret); > + return ret < 0 ? ret : -EIO; > + } > + > + new_dpcd_buf = dpcd_buf; > + > + if ((dpcd_buf & DP_EDP_BACKLIGHT_CONTROL_MODE_MASK) != DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD) { > + new_dpcd_buf &= ~DP_EDP_BACKLIGHT_CONTROL_MODE_MASK; > + new_dpcd_buf |= DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD; > + > + ret = drm_dp_dpcd_writeb(aux, DP_EDP_PWMGEN_BIT_COUNT, bl->pwmgen_bit_count); > + if (ret != 1) > + DRM_DEBUG_KMS("%s: Failed to write aux pwmgen bit count: %d\n", > + aux->name, ret); > + } > + > + if (bl->pwm_freq_pre_divider) { > + ret = drm_dp_dpcd_writeb(aux, DP_EDP_BACKLIGHT_FREQ_SET, bl->pwm_freq_pre_divider); > + if (ret != 1) > + DRM_DEBUG_KMS("%s: Failed to write aux backlight frequency: %d\n", > + aux->name, ret); > + else > + new_dpcd_buf |= DP_EDP_BACKLIGHT_FREQ_AUX_SET_ENABLE; > + } > + > + if (new_dpcd_buf != dpcd_buf) { > + ret = drm_dp_dpcd_writeb(aux, DP_EDP_BACKLIGHT_MODE_SET_REGISTER, new_dpcd_buf); > + if (ret != 1) { > + DRM_DEBUG_KMS("%s: Failed to write aux backlight mode: %d\n", > + aux->name, ret); > + return ret < 0 ? ret : -EIO; > + } > + } > + > + ret = drm_edp_backlight_set_level(aux, bl, level); > + if (ret < 0) > + return ret; > + ret = drm_edp_backlight_set_enable(aux, bl, true); > + if (ret < 0) > + return ret; > + > + return 0; > +} > +EXPORT_SYMBOL(drm_edp_backlight_enable); > + > +/** > + * drm_edp_backlight_disable() - Disable an eDP backlight using DPCD, if supported > + * @aux: The DP AUX channel to use > + * @bl: Backlight capability info from drm_edp_backlight_init() > + * > + * This function handles disabling DPCD backlight controls on a panel over AUX. Note that some > + * panels have backlights that are enabled/disabled by other means, despite having their brightness > + * values controlled through DPCD. On such panels &drm_edp_backlight_info.aux_enable will be set to > + * %false, this function will become a no-op (and we will skip updating > + * %DP_EDP_DISPLAY_CONTROL_REGISTER), and the driver must take care to perform it's own > + * implementation specific step for disabling the backlight. > + * > + * Returns: %0 on success or no-op, negative error code on failure. > + */ > +int drm_edp_backlight_disable(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl) > +{ > + int ret; > + > + ret = drm_edp_backlight_set_enable(aux, bl, false); > + if (ret < 0) > + return ret; > + > + return 0; > +} > +EXPORT_SYMBOL(drm_edp_backlight_disable); > + > +static inline int > +drm_edp_backlight_probe_max(struct drm_dp_aux *aux, struct drm_edp_backlight_info *bl, > + u16 driver_pwm_freq_hz, const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE]) > +{ > + int fxp, fxp_min, fxp_max, fxp_actual, f = 1; > + int ret; > + u8 pn, pn_min, pn_max; > + > + ret = drm_dp_dpcd_readb(aux, DP_EDP_PWMGEN_BIT_COUNT, &pn); > + if (ret != 1) { > + DRM_DEBUG_KMS("%s: Failed to read pwmgen bit count cap: %d\n", aux->name, ret); > + return -ENODEV; > + } > + > + pn &= DP_EDP_PWMGEN_BIT_COUNT_MASK; > + bl->max = (1 << pn) - 1; > + if (!driver_pwm_freq_hz) > + return 0; > + > + /* > + * Set PWM Frequency divider to match desired frequency provided by the driver. > + * The PWM Frequency is calculated as 27Mhz / (F x P). > + * - Where F = PWM Frequency Pre-Divider value programmed by field 7:0 of the > + * EDP_BACKLIGHT_FREQ_SET register (DPCD Address 00728h) > + * - Where P = 2^Pn, where Pn is the value programmed by field 4:0 of the > + * EDP_PWMGEN_BIT_COUNT register (DPCD Address 00724h) > + */ > + > + /* Find desired value of (F x P) > + * Note that, if F x P is out of supported range, the maximum value or minimum value will > + * applied automatically. So no need to check that. > + */ > + fxp = DIV_ROUND_CLOSEST(1000 * DP_EDP_BACKLIGHT_FREQ_BASE_KHZ, driver_pwm_freq_hz); > + > + /* Use highest possible value of Pn for more granularity of brightness adjustment while > + * satifying the conditions below. > + * - Pn is in the range of Pn_min and Pn_max > + * - F is in the range of 1 and 255 > + * - FxP is within 25% of desired value. > + * Note: 25% is arbitrary value and may need some tweak. > + */ > + ret = drm_dp_dpcd_readb(aux, DP_EDP_PWMGEN_BIT_COUNT_CAP_MIN, &pn_min); > + if (ret != 1) { > + DRM_DEBUG_KMS("%s: Failed to read pwmgen bit count cap min: %d\n", aux->name, ret); > + return 0; > + } > + ret = drm_dp_dpcd_readb(aux, DP_EDP_PWMGEN_BIT_COUNT_CAP_MAX, &pn_max); > + if (ret != 1) { > + DRM_DEBUG_KMS("%s: Failed to read pwmgen bit count cap max: %d\n", aux->name, ret); > + return 0; > + } > + pn_min &= DP_EDP_PWMGEN_BIT_COUNT_MASK; > + pn_max &= DP_EDP_PWMGEN_BIT_COUNT_MASK; > + > + /* Ensure frequency is within 25% of desired value */ > + fxp_min = DIV_ROUND_CLOSEST(fxp * 3, 4); > + fxp_max = DIV_ROUND_CLOSEST(fxp * 5, 4); > + if (fxp_min < (1 << pn_min) || (255 << pn_max) < fxp_max) { > + DRM_DEBUG_KMS("%s: Driver defined backlight frequency (%d) out of range\n", > + aux->name, driver_pwm_freq_hz); > + return 0; > + } > + > + for (pn = pn_max; pn >= pn_min; pn--) { > + f = clamp(DIV_ROUND_CLOSEST(fxp, 1 << pn), 1, 255); > + fxp_actual = f << pn; > + if (fxp_min <= fxp_actual && fxp_actual <= fxp_max) > + break; > + } > + > + ret = drm_dp_dpcd_writeb(aux, DP_EDP_PWMGEN_BIT_COUNT, pn); > + if (ret != 1) { > + DRM_DEBUG_KMS("%s: Failed to write aux pwmgen bit count: %d\n", aux->name, ret); > + return 0; > + } > + bl->pwmgen_bit_count = pn; > + bl->max = (1 << pn) - 1; > + > + if (edp_dpcd[2] & DP_EDP_BACKLIGHT_FREQ_AUX_SET_CAP) { > + bl->pwm_freq_pre_divider = f; > + DRM_DEBUG_KMS("%s: Using backlight frequency from driver (%dHz)\n", > + aux->name, driver_pwm_freq_hz); > + } > + > + return 0; > +} > + > +static inline int > +drm_edp_backlight_probe_level(struct drm_dp_aux *aux, struct drm_edp_backlight_info *bl, > + u8 *current_mode) > +{ > + int ret; > + u8 buf[2]; > + u8 mode_reg; > + > + ret = drm_dp_dpcd_readb(aux, DP_EDP_BACKLIGHT_MODE_SET_REGISTER, &mode_reg); > + if (ret != 1) { > + DRM_DEBUG_KMS("%s: Failed to read backlight mode: %d\n", aux->name, ret); > + return ret < 0 ? ret : -EIO; > + } > + > + *current_mode = (mode_reg & DP_EDP_BACKLIGHT_CONTROL_MODE_MASK); > + if (*current_mode == DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD) { > + int size = 1 + bl->lsb_reg_used; > + > + ret = drm_dp_dpcd_read(aux, DP_EDP_BACKLIGHT_BRIGHTNESS_MSB, buf, size); > + if (ret != size) { > + DRM_DEBUG_KMS("%s: Failed to read backlight level: %d\n", aux->name, ret); > + return ret < 0 ? ret : -EIO; > + } > + > + if (bl->lsb_reg_used) > + return (buf[0] << 8) | buf[1]; > + else > + return buf[0]; > + } > + > + /* > + * If we're not in DPCD control mode yet, the programmed brightness value is meaningless and > + * the driver should assume max brightness > + */ > + return bl->max; > +} > + > +/** > + * drm_edp_backlight_init() - Probe a display panel's TCON using the standard VESA eDP backlight > + * interface. > + * @aux: The DP aux device to use for probing > + * @bl: The &drm_edp_backlight_info struct to fill out with information on the backlight > + * @driver_pwm_freq_hz: Optional PWM frequency from the driver in hz > + * @edp_dpcd: A cached copy of the eDP DPCD > + * @current_level: Where to store the probed brightness level > + * @current_mode: Where to store the currently set backlight control mode > + * > + * Initializes a &drm_edp_backlight_info struct by probing @aux for it's backlight capabilities, > + * along with also probing the current and maximum supported brightness levels. > + * > + * If @driver_pwm_freq_hz is non-zero, this will be used as the backlight frequency. Otherwise, the > + * default frequency from the panel is used. > + * > + * Returns: %0 on success, negative error code on failure. > + */ > +int > +drm_edp_backlight_init(struct drm_dp_aux *aux, struct drm_edp_backlight_info *bl, > + u16 driver_pwm_freq_hz, const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE], > + u16 *current_level, u8 *current_mode) > +{ > + int ret; > + > + if (edp_dpcd[1] & DP_EDP_BACKLIGHT_AUX_ENABLE_CAP) > + bl->aux_enable = true; > + if (edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_BYTE_COUNT) > + bl->lsb_reg_used = true; > + > + ret = drm_edp_backlight_probe_max(aux, bl, driver_pwm_freq_hz, edp_dpcd); > + if (ret < 0) > + return ret; > + > + ret = drm_edp_backlight_probe_level(aux, bl, current_mode); > + if (ret < 0) > + return ret; > + *current_level = ret; > + > + DRM_DEBUG_KMS("%s: Found backlight level=%d/%d pwm_freq_pre_divider=%d mode=%x\n", > + aux->name, *current_level, bl->max, bl->pwm_freq_pre_divider, *current_mode); > + DRM_DEBUG_KMS("%s: Backlight caps: pwmgen_bit_count=%d lsb_reg_used=%d aux_enable=%d\n", > + aux->name, bl->pwmgen_bit_count, bl->lsb_reg_used, bl->aux_enable); > + return 0; > +} > +EXPORT_SYMBOL(drm_edp_backlight_init); > diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h > index 133c9cb742a7..82673e8f21c3 100644 > --- a/drivers/gpu/drm/i915/display/intel_display_types.h > +++ b/drivers/gpu/drm/i915/display/intel_display_types.h > @@ -257,11 +257,8 @@ struct intel_panel { > struct pwm_device *pwm; > struct pwm_state pwm_state; > > - /* DPCD backlight */ > - u8 pwmgen_bit_count; > - u8 pwm_freq_pre_divider; > - > struct backlight_device *device; > + struct drm_edp_backlight_info vesa_edp_info; > > const struct intel_panel_bl_funcs *funcs; > void (*power)(struct intel_connector *, bool enable); > diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c > index 94ce5ca1affa..b1ebfd854a42 100644 > --- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c > +++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c > @@ -25,303 +25,73 @@ > #include "intel_display_types.h" > #include "intel_dp_aux_backlight.h" > > -static void set_aux_backlight_enable(struct intel_dp *intel_dp, bool enable) > -{ > - struct drm_i915_private *i915 = dp_to_i915(intel_dp); > - u8 reg_val = 0; > - > - /* Early return when display use other mechanism to enable backlight. */ > - if (!(intel_dp->edp_dpcd[1] & DP_EDP_BACKLIGHT_AUX_ENABLE_CAP)) > - return; > - > - if (drm_dp_dpcd_readb(&intel_dp->aux, DP_EDP_DISPLAY_CONTROL_REGISTER, > - ®_val) < 0) { > - drm_dbg_kms(&i915->drm, "Failed to read DPCD register 0x%x\n", > - DP_EDP_DISPLAY_CONTROL_REGISTER); > - return; > - } > - if (enable) > - reg_val |= DP_EDP_BACKLIGHT_ENABLE; > - else > - reg_val &= ~(DP_EDP_BACKLIGHT_ENABLE); > - > - if (drm_dp_dpcd_writeb(&intel_dp->aux, DP_EDP_DISPLAY_CONTROL_REGISTER, > - reg_val) != 1) { > - drm_dbg_kms(&i915->drm, "Failed to %s aux backlight\n", > - enable ? "enable" : "disable"); > - } > -} > - > -static bool intel_dp_aux_backlight_dpcd_mode(struct intel_connector *connector) > -{ > - struct intel_dp *intel_dp = intel_attached_dp(connector); > - struct drm_i915_private *i915 = dp_to_i915(intel_dp); > - u8 mode_reg; > - > - if (drm_dp_dpcd_readb(&intel_dp->aux, > - DP_EDP_BACKLIGHT_MODE_SET_REGISTER, > - &mode_reg) != 1) { > - drm_dbg_kms(&i915->drm, > - "Failed to read the DPCD register 0x%x\n", > - DP_EDP_BACKLIGHT_MODE_SET_REGISTER); > - return false; > - } > - > - return (mode_reg & DP_EDP_BACKLIGHT_CONTROL_MODE_MASK) == > - DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD; > -} > - > -/* > - * Read the current backlight value from DPCD register(s) based > - * on if 8-bit(MSB) or 16-bit(MSB and LSB) values are supported > - */ > static u32 intel_dp_aux_get_backlight(struct intel_connector *connector) > { > - struct intel_dp *intel_dp = intel_attached_dp(connector); > - struct drm_i915_private *i915 = dp_to_i915(intel_dp); > - u8 read_val[2] = { 0x0 }; > - u16 level = 0; > - > - /* > - * If we're not in DPCD control mode yet, the programmed brightness > - * value is meaningless and we should assume max brightness > - */ > - if (!intel_dp_aux_backlight_dpcd_mode(connector)) > - return connector->panel.backlight.max; > - > - if (drm_dp_dpcd_read(&intel_dp->aux, DP_EDP_BACKLIGHT_BRIGHTNESS_MSB, > - &read_val, sizeof(read_val)) < 0) { > - drm_dbg_kms(&i915->drm, "Failed to read DPCD register 0x%x\n", > - DP_EDP_BACKLIGHT_BRIGHTNESS_MSB); > - return 0; > - } > - level = read_val[0]; > - if (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_BYTE_COUNT) > - level = (read_val[0] << 8 | read_val[1]); > - > - return level; > + return connector->panel.backlight.level; > } > > -/* > - * Sends the current backlight level over the aux channel, checking if its using > - * 8-bit or 16 bit value (MSB and LSB) > - */ > static void > -intel_dp_aux_set_backlight(const struct drm_connector_state *conn_state, u32 level) > +intel_dp_aux_set_backlight(const struct drm_connector_state *conn_state, > + u32 level) > { > struct intel_connector *connector = to_intel_connector(conn_state->connector); > - struct intel_dp *intel_dp = intel_attached_dp(connector); > - struct drm_i915_private *i915 = dp_to_i915(intel_dp); > - u8 vals[2] = { 0x0 }; > - > - vals[0] = level; > + struct intel_panel *panel = &connector->panel; > + struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder); > > - /* Write the MSB and/or LSB */ > - if (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_BYTE_COUNT) { > - vals[0] = (level & 0xFF00) >> 8; > - vals[1] = (level & 0xFF); > - } > - if (drm_dp_dpcd_write(&intel_dp->aux, DP_EDP_BACKLIGHT_BRIGHTNESS_MSB, > - vals, sizeof(vals)) < 0) { > - drm_dbg_kms(&i915->drm, > - "Failed to write aux backlight level\n"); > - return; > - } > + drm_edp_backlight_set_level(&intel_dp->aux, &panel->backlight.vesa_edp_info, level); > } > > -static void intel_dp_aux_enable_backlight(const struct intel_crtc_state *crtc_state, > - const struct drm_connector_state *conn_state) > +static void > +intel_dp_aux_enable_backlight(const struct intel_crtc_state *crtc_state, > + const struct drm_connector_state *conn_state) > { > struct intel_connector *connector = to_intel_connector(conn_state->connector); > - struct intel_dp *intel_dp = intel_attached_dp(connector); > - struct drm_i915_private *i915 = dp_to_i915(intel_dp); > struct intel_panel *panel = &connector->panel; > - u8 dpcd_buf, new_dpcd_buf, edp_backlight_mode; > - > - if (drm_dp_dpcd_readb(&intel_dp->aux, > - DP_EDP_BACKLIGHT_MODE_SET_REGISTER, &dpcd_buf) != 1) { > - drm_dbg_kms(&i915->drm, "Failed to read DPCD register 0x%x\n", > - DP_EDP_BACKLIGHT_MODE_SET_REGISTER); > - return; > - } > - > - new_dpcd_buf = dpcd_buf; > - edp_backlight_mode = dpcd_buf & DP_EDP_BACKLIGHT_CONTROL_MODE_MASK; > - > - switch (edp_backlight_mode) { > - case DP_EDP_BACKLIGHT_CONTROL_MODE_PWM: > - case DP_EDP_BACKLIGHT_CONTROL_MODE_PRESET: > - case DP_EDP_BACKLIGHT_CONTROL_MODE_PRODUCT: > - new_dpcd_buf &= ~DP_EDP_BACKLIGHT_CONTROL_MODE_MASK; > - new_dpcd_buf |= DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD; > - > - if (drm_dp_dpcd_writeb(&intel_dp->aux, > - DP_EDP_PWMGEN_BIT_COUNT, > - panel->backlight.pwmgen_bit_count) < 0) > - drm_dbg_kms(&i915->drm, > - "Failed to write aux pwmgen bit count\n"); > - > - break; > - > - /* Do nothing when it is already DPCD mode */ > - case DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD: > - default: > - break; > - } > - > - if (panel->backlight.pwm_freq_pre_divider) { > - if (drm_dp_dpcd_writeb(&intel_dp->aux, DP_EDP_BACKLIGHT_FREQ_SET, > - panel->backlight.pwm_freq_pre_divider) == 1) > - new_dpcd_buf |= DP_EDP_BACKLIGHT_FREQ_AUX_SET_ENABLE; > - else > - drm_dbg_kms(&i915->drm, "Failed to write aux backlight frequency\n"); > - } > + struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder); > > - if (new_dpcd_buf != dpcd_buf) { > - if (drm_dp_dpcd_writeb(&intel_dp->aux, > - DP_EDP_BACKLIGHT_MODE_SET_REGISTER, new_dpcd_buf) < 0) { > - drm_dbg_kms(&i915->drm, > - "Failed to write aux backlight mode\n"); > - } > - } > - > - intel_dp_aux_set_backlight(conn_state, > - connector->panel.backlight.level); > - set_aux_backlight_enable(intel_dp, true); > + drm_edp_backlight_enable(&intel_dp->aux, &panel->backlight.vesa_edp_info, > + panel->backlight.level); > } > > -static void intel_dp_aux_disable_backlight(const struct drm_connector_state *old_conn_state) > -{ > - set_aux_backlight_enable(enc_to_intel_dp(to_intel_encoder(old_conn_state->best_encoder)), > - false); > -} > - > -/* > - * Compute PWM frequency divider value based off the frequency provided to us by the vbt. > - * The PWM Frequency is calculated as 27Mhz / (F x P). > - * - Where F = PWM Frequency Pre-Divider value programmed by field 7:0 of the > - * EDP_BACKLIGHT_FREQ_SET register (DPCD Address 00728h) > - * - Where P = 2^Pn, where Pn is the value programmed by field 4:0 of the > - * EDP_PWMGEN_BIT_COUNT register (DPCD Address 00724h) > - */ > -static u32 intel_dp_aux_calc_max_backlight(struct intel_connector *connector) > +static void > +intel_dp_aux_disable_backlight(const struct drm_connector_state *old_conn_state) > { > - struct drm_i915_private *i915 = to_i915(connector->base.dev); > - struct intel_dp *intel_dp = intel_attached_dp(connector); > + struct intel_connector *connector = to_intel_connector(old_conn_state->connector); > struct intel_panel *panel = &connector->panel; > - u32 max_backlight = 0; > - int freq, fxp, fxp_min, fxp_max, fxp_actual, f = 1; > - u8 pn, pn_min, pn_max; > - > - if (drm_dp_dpcd_readb(&intel_dp->aux, DP_EDP_PWMGEN_BIT_COUNT, &pn) == 1) { > - pn &= DP_EDP_PWMGEN_BIT_COUNT_MASK; > - max_backlight = (1 << pn) - 1; > - } > - > - /* Find desired value of (F x P) > - * Note that, if F x P is out of supported range, the maximum value or > - * minimum value will applied automatically. So no need to check that. > - */ > - freq = i915->vbt.backlight.pwm_freq_hz; > - drm_dbg_kms(&i915->drm, "VBT defined backlight frequency %u Hz\n", > - freq); > - if (!freq) { > - drm_dbg_kms(&i915->drm, > - "Use panel default backlight frequency\n"); > - return max_backlight; > - } > - > - fxp = DIV_ROUND_CLOSEST(KHz(DP_EDP_BACKLIGHT_FREQ_BASE_KHZ), freq); > - > - /* Use highest possible value of Pn for more granularity of brightness > - * adjustment while satifying the conditions below. > - * - Pn is in the range of Pn_min and Pn_max > - * - F is in the range of 1 and 255 > - * - FxP is within 25% of desired value. > - * Note: 25% is arbitrary value and may need some tweak. > - */ > - if (drm_dp_dpcd_readb(&intel_dp->aux, > - DP_EDP_PWMGEN_BIT_COUNT_CAP_MIN, &pn_min) != 1) { > - drm_dbg_kms(&i915->drm, > - "Failed to read pwmgen bit count cap min\n"); > - return max_backlight; > - } > - if (drm_dp_dpcd_readb(&intel_dp->aux, > - DP_EDP_PWMGEN_BIT_COUNT_CAP_MAX, &pn_max) != 1) { > - drm_dbg_kms(&i915->drm, > - "Failed to read pwmgen bit count cap max\n"); > - return max_backlight; > - } > - pn_min &= DP_EDP_PWMGEN_BIT_COUNT_MASK; > - pn_max &= DP_EDP_PWMGEN_BIT_COUNT_MASK; > + struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder); > > - /* Ensure frequency is within 25% of desired value */ > - fxp_min = DIV_ROUND_CLOSEST(fxp * 3, 4); > - fxp_max = DIV_ROUND_CLOSEST(fxp * 5, 4); > - > - if (fxp_min < (1 << pn_min) || (255 << pn_max) < fxp_max) { > - drm_dbg_kms(&i915->drm, > - "VBT defined backlight frequency out of range\n"); > - return max_backlight; > - } > - > - for (pn = pn_max; pn >= pn_min; pn--) { > - f = clamp(DIV_ROUND_CLOSEST(fxp, 1 << pn), 1, 255); > - fxp_actual = f << pn; > - if (fxp_min <= fxp_actual && fxp_actual <= fxp_max) > - break; > - } > - > - drm_dbg_kms(&i915->drm, "Using eDP pwmgen bit count of %d\n", pn); > - if (drm_dp_dpcd_writeb(&intel_dp->aux, > - DP_EDP_PWMGEN_BIT_COUNT, pn) < 0) { > - drm_dbg_kms(&i915->drm, > - "Failed to write aux pwmgen bit count\n"); > - return max_backlight; > - } > - > - panel->backlight.pwmgen_bit_count = pn; > - panel->backlight.pwm_freq_pre_divider = f; > - > - max_backlight = (1 << pn) - 1; > - > - return max_backlight; > + drm_edp_backlight_disable(&intel_dp->aux, &panel->backlight.vesa_edp_info); > } > > static int intel_dp_aux_setup_backlight(struct intel_connector *connector, > enum pipe pipe) > { > struct intel_panel *panel = &connector->panel; > + struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder); > + struct drm_i915_private *i915 = dp_to_i915(intel_dp); > + u16 current_level; > + u8 current_mode; > + int ret; > > - panel->backlight.max = intel_dp_aux_calc_max_backlight(connector); > - if (!panel->backlight.max) > - return -ENODEV; > + ret = drm_edp_backlight_init(&intel_dp->aux, &panel->backlight.vesa_edp_info, > + i915->vbt.backlight.pwm_freq_hz, intel_dp->edp_dpcd, > + ¤t_level, ¤t_mode); > + if (ret < 0) > + return ret; > > + panel->backlight.max = panel->backlight.vesa_edp_info.max; > panel->backlight.min = 0; > - panel->backlight.level = intel_dp_aux_get_backlight(connector); > - panel->backlight.enabled = intel_dp_aux_backlight_dpcd_mode(connector) && > - panel->backlight.level != 0; > + if (current_mode == DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD) { > + panel->backlight.level = current_level; > + panel->backlight.enabled = panel->backlight.level != 0; > + } else { > + panel->backlight.level = panel->backlight.max; > + panel->backlight.enabled = false; > + } > > return 0; > } > > -static bool > -intel_dp_aux_display_control_capable(struct intel_connector *connector) > -{ > - struct intel_dp *intel_dp = intel_attached_dp(connector); > - struct drm_i915_private *i915 = dp_to_i915(intel_dp); > - > - /* Check the eDP Display control capabilities registers to determine if > - * the panel can support backlight control over the aux channel > - */ > - if (intel_dp->edp_dpcd[1] & DP_EDP_TCON_BACKLIGHT_ADJUSTMENT_CAP && > - (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_AUX_SET_CAP)) { > - drm_dbg_kms(&i915->drm, "AUX Backlight Control Supported!\n"); > - return true; > - } > - return false; > -} > - > static const struct intel_panel_bl_funcs intel_dp_bl_funcs = { > .setup = intel_dp_aux_setup_backlight, > .enable = intel_dp_aux_enable_backlight, > @@ -337,9 +107,11 @@ int intel_dp_aux_init_backlight_funcs(struct intel_connector *intel_connector) > struct drm_i915_private *i915 = dp_to_i915(intel_dp); > > if (i915->params.enable_dpcd_backlight == 0 || > - !intel_dp_aux_display_control_capable(intel_connector)) > + !drm_edp_backlight_supported(intel_dp->edp_dpcd)) > return -ENODEV; > > + drm_dbg_kms(&i915->drm, "AUX Backlight Control Supported!\n"); > + > /* > * There are a lot of machines that don't advertise the backlight > * control interface to use properly in their VBIOS, :\ > diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h > index 6b40258927bf..082fb832d4f6 100644 > --- a/include/drm/drm_dp_helper.h > +++ b/include/drm/drm_dp_helper.h > @@ -1598,6 +1598,24 @@ drm_dp_sink_can_do_video_without_timing_msa(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) > DP_MSA_TIMING_PAR_IGNORED; > } > > +/** > + * drm_edp_backlight_supported() - Check an eDP DPCD for VESA backlight support > + * @edp_dpcd: The DPCD to check > + * > + * Note that currently this function will return %false for panels which support various DPCD > + * backlight features but which require the brightness be set through PWM, and don't support setting > + * the brightness level via the DPCD. This is a TODO. > + * > + * Returns: %True if @edp_dpcd indicates that VESA backlight controls are supported, %false > + * otherwise > + */ > +static inline bool > +drm_edp_backlight_supported(const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE]) > +{ > + return (edp_dpcd[1] & DP_EDP_TCON_BACKLIGHT_ADJUSTMENT_CAP) && > + (edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_AUX_SET_CAP); > +} > + > /* > * DisplayPort AUX channel > */ > @@ -1912,6 +1930,36 @@ drm_dp_has_quirk(const struct drm_dp_desc *desc, u32 edid_quirks, > return (desc->quirks | edid_quirks) & BIT(quirk); > } > > +/** > + * struct drm_edp_backlight_info - Probed eDP backlight info struct > + * @pwmgen_bit_count: The pwmgen bit count > + * @pwm_freq_pre_divider: The PWM frequency pre-divider value being used for this backlight, if any > + * @max: The maximum backlight level that may be set > + * @lsb_reg_used: Do we also write values to the DP_EDP_BACKLIGHT_BRIGHTNESS_LSB register? > + * @aux_enable: Does the panel support the AUX enable cap? > + * > + * This structure contains various data about an eDP backlight, which can be populated by using > + * drm_edp_backlight_init(). > + */ > +struct drm_edp_backlight_info { > + u8 pwmgen_bit_count; > + u8 pwm_freq_pre_divider; > + u16 max; > + > + bool lsb_reg_used : 1; > + bool aux_enable : 1; > +}; > + > +int > +drm_edp_backlight_init(struct drm_dp_aux *aux, struct drm_edp_backlight_info *bl, > + u16 driver_pwm_freq_hz, const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE], > + u16 *current_level, u8 *current_mode); > +int drm_edp_backlight_set_level(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl, > + u16 level); > +int drm_edp_backlight_enable(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl, > + u16 level); > +int drm_edp_backlight_disable(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl); > + > #ifdef CONFIG_DRM_DP_CEC > void drm_dp_cec_irq(struct drm_dp_aux *aux); > void drm_dp_cec_register_connector(struct drm_dp_aux *aux, -- Jani Nikula, Intel Open Source Graphics Center _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx