Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934392AbeAHPvV (ORCPT + 1 other); Mon, 8 Jan 2018 10:51:21 -0500 Received: from mail-yb0-f195.google.com ([209.85.213.195]:45348 "EHLO mail-yb0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933858AbeAHPvR (ORCPT ); Mon, 8 Jan 2018 10:51:17 -0500 X-Google-Smtp-Source: ACJfBovL/VwDHbQkgVQIJqE6j7ZuJiZ7l5RJBbICdWIjRkd4CrZogitGx+1tF5hnZwG+jGJuKIT4sQ== From: Sean Paul To: dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org Cc: linux-kernel@vger.kernel.org, daniel.vetter@intel.com, seanpaul@google.com, ramalingam.c@intel.com, Sean Paul , =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= , Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , David Airlie Subject: [PATCH v5 7/9] drm/i915: Add function to output Aksv over GMBUS Date: Mon, 8 Jan 2018 10:50:25 -0500 Message-Id: <20180108155029.244552-8-seanpaul@chromium.org> X-Mailer: git-send-email 2.16.0.rc0.223.g4a4ac83678-goog In-Reply-To: <20180108155029.244552-1-seanpaul@chromium.org> References: <20180108155029.244552-1-seanpaul@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: Once the Aksv is available in the PCH, we need to get it on the wire to the receiver via DDC. The hardware doesn't allow us to read the value directly, so we need to tell GMBUS to source the Aksv internally and send it to the right offset on the receiver. The way we do this is to initiate an indexed write where the index is the Aksv register offset. We write dummy values to GMBUS3 as if we were sending the key, and the hardware slips in the "real" values when it goes out. Changes in v2: - None Changes in v3: - Uses new index write feature (Ville) Changes in v4: - None Changes in v5: - checkpatch whitespace fix Cc: Ville Syrjälä Reviewed-by: Daniel Vetter Signed-off-by: Sean Paul --- drivers/gpu/drm/i915/i915_drv.h | 1 + drivers/gpu/drm/i915/i915_reg.h | 1 + drivers/gpu/drm/i915/intel_i2c.c | 47 +++++++++++++++++++++++++++++++++++++--- 3 files changed, 46 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index caebd5825279..a689396d0ff6 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -3644,6 +3644,7 @@ extern int intel_setup_gmbus(struct drm_i915_private *dev_priv); extern void intel_teardown_gmbus(struct drm_i915_private *dev_priv); extern bool intel_gmbus_is_valid_pin(struct drm_i915_private *dev_priv, unsigned int pin); +extern int intel_gmbus_output_aksv(struct i2c_adapter *adapter); extern struct i2c_adapter * intel_gmbus_get_adapter(struct drm_i915_private *dev_priv, unsigned int pin); diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index 5db8d18c73ab..571e5097887c 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -3043,6 +3043,7 @@ enum i915_power_well_id { # define GPIO_DATA_PULLUP_DISABLE (1 << 13) #define GMBUS0 _MMIO(dev_priv->gpio_mmio_base + 0x5100) /* clock/port select */ +#define GMBUS_AKSV_SELECT (1<<11) #define GMBUS_RATE_100KHZ (0<<8) #define GMBUS_RATE_50KHZ (1<<8) #define GMBUS_RATE_400KHZ (2<<8) /* reserved on Pineview */ diff --git a/drivers/gpu/drm/i915/intel_i2c.c b/drivers/gpu/drm/i915/intel_i2c.c index d9e6993fa718..6f7ef4e225ee 100644 --- a/drivers/gpu/drm/i915/intel_i2c.c +++ b/drivers/gpu/drm/i915/intel_i2c.c @@ -30,6 +30,7 @@ #include #include #include +#include #include "intel_drv.h" #include #include "i915_drv.h" @@ -507,7 +508,8 @@ gmbus_index_xfer(struct drm_i915_private *dev_priv, struct i2c_msg *msgs) } static int -do_gmbus_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, int num) +do_gmbus_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, int num, + u32 gmbus0_source) { struct intel_gmbus *bus = container_of(adapter, struct intel_gmbus, @@ -524,7 +526,7 @@ do_gmbus_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, int num) pch_gmbus_clock_gating(dev_priv, false); retry: - I915_WRITE_FW(GMBUS0, bus->reg0); + I915_WRITE_FW(GMBUS0, gmbus0_source | bus->reg0); for (; i < num; i += inc) { inc = 1; @@ -649,7 +651,7 @@ gmbus_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, int num) if (ret < 0) bus->force_bit &= ~GMBUS_FORCE_BIT_RETRY; } else { - ret = do_gmbus_xfer(adapter, msgs, num); + ret = do_gmbus_xfer(adapter, msgs, num, 0); if (ret == -EAGAIN) bus->force_bit |= GMBUS_FORCE_BIT_RETRY; } @@ -659,6 +661,45 @@ gmbus_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, int num) return ret; } +int intel_gmbus_output_aksv(struct i2c_adapter *adapter) +{ + struct intel_gmbus *bus = container_of(adapter, struct intel_gmbus, + adapter); + struct drm_i915_private *dev_priv = bus->dev_priv; + int ret; + u8 cmd = DRM_HDCP_DDC_AKSV; + u8 buf[DRM_HDCP_KSV_LEN] = { 0 }; + struct i2c_msg msgs[] = { + { + .addr = DRM_HDCP_DDC_ADDR, + .flags = 0, + .len = sizeof(cmd), + .buf = &cmd, + }, + { + .addr = DRM_HDCP_DDC_ADDR, + .flags = 0, + .len = sizeof(buf), + .buf = buf, + } + }; + + intel_display_power_get(dev_priv, POWER_DOMAIN_GMBUS); + mutex_lock(&dev_priv->gmbus_mutex); + + /* + * In order to output Aksv to the receiver, use an indexed write to + * pass the i2c command, and tell GMBUS to use the HW-provided value + * instead of sourcing GMBUS3 for the data. + */ + ret = do_gmbus_xfer(adapter, msgs, ARRAY_SIZE(msgs), GMBUS_AKSV_SELECT); + + mutex_unlock(&dev_priv->gmbus_mutex); + intel_display_power_put(dev_priv, POWER_DOMAIN_GMBUS); + + return ret; +} + static u32 gmbus_func(struct i2c_adapter *adapter) { return i2c_bit_algo.functionality(adapter) & -- 2.16.0.rc0.223.g4a4ac83678-goog