From patchwork Tue May 18 14:19:26 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dafna Hirschfeld X-Patchwork-Id: 12264899 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 2663CC43461 for ; Tue, 18 May 2021 14:19:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0A48C61355 for ; Tue, 18 May 2021 14:19:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349965AbhEROVB (ORCPT ); Tue, 18 May 2021 10:21:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52940 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349960AbhEROVA (ORCPT ); Tue, 18 May 2021 10:21:00 -0400 Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e3e3]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D91C5C061573; Tue, 18 May 2021 07:19:42 -0700 (PDT) Received: from guri.fritz.box (unknown [IPv6:2a02:810a:880:f54:8085:99d1:d3e8:47cc]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: dafna) by bhuna.collabora.co.uk (Postfix) with ESMTPSA id 72A291F42B08; Tue, 18 May 2021 15:19:40 +0100 (BST) From: Dafna Hirschfeld To: devicetree@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org Cc: megous@megous.com, linux-usb@vger.kernel.org, a.hajda@samsung.com, narmstrong@baylibre.com, Laurent.pinchart@ideasonboard.com, jonas@kwiboo.se, jernej.skrabec@siol.net, airlied@linux.ie, daniel@ffwll.ch, chunkuang.hu@kernel.org, p.zabel@pengutronix.de, enric.balletbo@collabora.com, drinkcat@chromium.org, hsinyi@chromium.org, kernel@collabora.com, dafna3@gmail.com, dafna.hirschfeld@collabora.com, robh+dt@kernel.org Subject: [PATCH v6 RESEND 1/2] dt-bindings: display: add google,cros-ec-anx7688.yaml Date: Tue, 18 May 2021 16:19:26 +0200 Message-Id: <20210518141927.24795-2-dafna.hirschfeld@collabora.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210518141927.24795-1-dafna.hirschfeld@collabora.com> References: <20210518141927.24795-1-dafna.hirschfeld@collabora.com> Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org ChromeOS EC ANX7688 is a display bridge that converts HDMI 2.0 to DisplayPort 1.3 Ultra-HDi (4096x2160p60). It is an Analogix ANX7688 chip which is connected to and operated by the ChromeOS Embedded Controller (See google,cros-ec.yaml). It is accessed using I2C tunneling through the EC and therefore its node should be a child of an EC I2C tunnel node (See google,cros-ec-i2c-tunnel.yaml). ChromOS EC ANX7688 is found on Acer Chromebook R13 (elm) Signed-off-by: Dafna Hirschfeld Reviewed-by: Rob Herring --- .../bridge/google,cros-ec-anx7688.yaml | 82 +++++++++++++++++++ 1 file changed, 82 insertions(+) create mode 100644 Documentation/devicetree/bindings/display/bridge/google,cros-ec-anx7688.yaml diff --git a/Documentation/devicetree/bindings/display/bridge/google,cros-ec-anx7688.yaml b/Documentation/devicetree/bindings/display/bridge/google,cros-ec-anx7688.yaml new file mode 100644 index 000000000000..9f7cc6b757cb --- /dev/null +++ b/Documentation/devicetree/bindings/display/bridge/google,cros-ec-anx7688.yaml @@ -0,0 +1,82 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/display/bridge/google,cros-ec-anx7688.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: ChromeOS EC ANX7688 HDMI to DP Converter through Type-C Port + +maintainers: + - Nicolas Boichat + - Enric Balletbo i Serra + +description: | + ChromeOS EC ANX7688 is a display bridge that converts HDMI 2.0 to + DisplayPort 1.3 Ultra-HDi (4096x2160p60). It is an Analogix ANX7688 chip + which is connected to and operated by the ChromeOS Embedded Controller + (See google,cros-ec.yaml). It is accessed using I2C tunneling through + the EC and therefore its node should be a child of an EC I2C tunnel node + (See google,cros-ec-i2c-tunnel.yaml). + +properties: + compatible: + const: google,cros-ec-anx7688 + + reg: + maxItems: 1 + description: I2C address of the device. + + ports: + $ref: /schemas/graph.yaml#/properties/ports + + properties: + port@0: + $ref: /schemas/graph.yaml#/properties/port + description: Video port for HDMI input. + + port@1: + $ref: /schemas/graph.yaml#/properties/port + description: USB Type-c connector. + + required: + - port@0 + - port@1 + +required: + - compatible + - reg + - ports + +additionalProperties: false + +examples: + - | + i2c_tunnel_b: i2c-tunnel1 { + compatible = "google,cros-ec-i2c-tunnel"; + google,remote-bus = <1>; + #address-cells = <1>; + #size-cells = <0>; + + anx7688: anx7688@2c { + compatible = "google,cros-ec-anx7688"; + reg = <0x2c>; + + ports { + #address-cells = <1>; + #size-cells = <0>; + port@0 { + reg = <0>; + anx7688_in: endpoint { + remote-endpoint = <&hdmi0_out>; + }; + }; + port@1 { + reg = <1>; + anx7688_out: endpoint { + remote-endpoint = <&typec_connector>; + }; + }; + }; + }; + }; + From patchwork Tue May 18 14:19:27 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dafna Hirschfeld X-Patchwork-Id: 12264901 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 F2FEBC433B4 for ; Tue, 18 May 2021 14:19:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D54C2611CE for ; Tue, 18 May 2021 14:19:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349966AbhEROVE (ORCPT ); Tue, 18 May 2021 10:21:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52942 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349963AbhEROVB (ORCPT ); Tue, 18 May 2021 10:21:01 -0400 Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e3e3]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6998BC061756; Tue, 18 May 2021 07:19:43 -0700 (PDT) Received: from guri.fritz.box (unknown [IPv6:2a02:810a:880:f54:8085:99d1:d3e8:47cc]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: dafna) by bhuna.collabora.co.uk (Postfix) with ESMTPSA id 4FADF1F42B0D; Tue, 18 May 2021 15:19:41 +0100 (BST) From: Dafna Hirschfeld To: devicetree@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org Cc: megous@megous.com, linux-usb@vger.kernel.org, a.hajda@samsung.com, narmstrong@baylibre.com, Laurent.pinchart@ideasonboard.com, jonas@kwiboo.se, jernej.skrabec@siol.net, airlied@linux.ie, daniel@ffwll.ch, chunkuang.hu@kernel.org, p.zabel@pengutronix.de, enric.balletbo@collabora.com, drinkcat@chromium.org, hsinyi@chromium.org, kernel@collabora.com, dafna3@gmail.com, dafna.hirschfeld@collabora.com, robh+dt@kernel.org Subject: [PATCH v6 RESEND 2/2] drm/bridge: Add ChromeOS EC ANX7688 bridge driver support Date: Tue, 18 May 2021 16:19:27 +0200 Message-Id: <20210518141927.24795-3-dafna.hirschfeld@collabora.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210518141927.24795-1-dafna.hirschfeld@collabora.com> References: <20210518141927.24795-1-dafna.hirschfeld@collabora.com> Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org From: Enric Balletbo i Serra This driver adds support for the ChromeOS EC ANX7688 HDMI to DP converter For our use case, the only reason the Linux kernel driver is necessary is to reject resolutions that require more bandwidth than what is available on the DP side. DP bandwidth and lane count are reported by the bridge via 2 registers and, as far as we know, only chips that have a firmware version greater than 0.85 support these two registers. Signed-off-by: Nicolas Boichat Signed-off-by: Hsin-Yi Wang [The driver is OF only so should depends on CONFIG_OF] Reported-by: kbuild test robot Signed-off-by: Enric Balletbo i Serra [convert to i2c driver, rename to cros_ec_anx7688, add err checks] Signed-off-by: Dafna Hirschfeld Reviewed-by: Laurent Pinchart --- drivers/gpu/drm/bridge/Kconfig | 12 ++ drivers/gpu/drm/bridge/Makefile | 1 + drivers/gpu/drm/bridge/cros-ec-anx7688.c | 191 +++++++++++++++++++++++ 3 files changed, 204 insertions(+) create mode 100644 drivers/gpu/drm/bridge/cros-ec-anx7688.c diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig index 630072f3ab59..7e9df06bae19 100644 --- a/drivers/gpu/drm/bridge/Kconfig +++ b/drivers/gpu/drm/bridge/Kconfig @@ -50,6 +50,18 @@ config DRM_CHRONTEL_CH7033 If in doubt, say "N". +config DRM_CROS_EC_ANX7688 + tristate "ChromeOS EC ANX7688 bridge" + depends on OF + select DRM_KMS_HELPER + select REGMAP_I2C + help + ChromeOS EC ANX7688 is an ultra-low power + 4K Ultra-HD (4096x2160p60) mobile HD transmitter + designed for ChromeOS devices. It converts HDMI + 2.0 to DisplayPort 1.3 Ultra-HD. It is connected + to the ChromeOS Embedded Controller. + config DRM_DISPLAY_CONNECTOR tristate "Display connector support" depends on OF diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile index b017ec182b8f..ae27ef374ef3 100644 --- a/drivers/gpu/drm/bridge/Makefile +++ b/drivers/gpu/drm/bridge/Makefile @@ -2,6 +2,7 @@ obj-$(CONFIG_DRM_CDNS_DSI) += cdns-dsi.o obj-$(CONFIG_DRM_CHIPONE_ICN6211) += chipone-icn6211.o obj-$(CONFIG_DRM_CHRONTEL_CH7033) += chrontel-ch7033.o +obj-$(CONFIG_DRM_CROS_EC_ANX7688) += cros-ec-anx7688.o obj-$(CONFIG_DRM_DISPLAY_CONNECTOR) += display-connector.o obj-$(CONFIG_DRM_LONTIUM_LT8912B) += lontium-lt8912b.o obj-$(CONFIG_DRM_LONTIUM_LT9611) += lontium-lt9611.o diff --git a/drivers/gpu/drm/bridge/cros-ec-anx7688.c b/drivers/gpu/drm/bridge/cros-ec-anx7688.c new file mode 100644 index 000000000000..0f6d907432e3 --- /dev/null +++ b/drivers/gpu/drm/bridge/cros-ec-anx7688.c @@ -0,0 +1,191 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * CrOS EC ANX7688 HDMI->DP bridge driver + * + * Copyright 2020 Google LLC + */ + +#include +#include +#include +#include +#include +#include + +/* Register addresses */ +#define ANX7688_VENDOR_ID_REG 0x00 +#define ANX7688_DEVICE_ID_REG 0x02 + +#define ANX7688_FW_VERSION_REG 0x80 + +#define ANX7688_DP_BANDWIDTH_REG 0x85 +#define ANX7688_DP_LANE_COUNT_REG 0x86 + +#define ANX7688_VENDOR_ID 0x1f29 +#define ANX7688_DEVICE_ID 0x7688 + +/* First supported firmware version (0.85) */ +#define ANX7688_MINIMUM_FW_VERSION 0x0085 + +static const struct regmap_config cros_ec_anx7688_regmap_config = { + .reg_bits = 8, + .val_bits = 8, +}; + +struct cros_ec_anx7688 { + struct i2c_client *client; + struct regmap *regmap; + struct drm_bridge bridge; + bool filter; +}; + +static inline struct cros_ec_anx7688 * +bridge_to_cros_ec_anx7688(struct drm_bridge *bridge) +{ + return container_of(bridge, struct cros_ec_anx7688, bridge); +} + +static bool cros_ec_anx7688_bridge_mode_fixup(struct drm_bridge *bridge, + const struct drm_display_mode *mode, + struct drm_display_mode *adjusted_mode) +{ + struct cros_ec_anx7688 *anx = bridge_to_cros_ec_anx7688(bridge); + int totalbw, requiredbw; + u8 dpbw, lanecount; + u8 regs[2]; + int ret; + + if (!anx->filter) + return true; + + /* Read both regs 0x85 (bandwidth) and 0x86 (lane count). */ + ret = regmap_bulk_read(anx->regmap, ANX7688_DP_BANDWIDTH_REG, regs, 2); + if (ret < 0) { + DRM_ERROR("Failed to read bandwidth/lane count\n"); + return false; + } + dpbw = regs[0]; + lanecount = regs[1]; + + /* Maximum 0x19 bandwidth (6.75 Gbps Turbo mode), 2 lanes */ + if (dpbw > 0x19 || lanecount > 2) { + DRM_ERROR("Invalid bandwidth/lane count (%02x/%d)\n", dpbw, + lanecount); + return false; + } + + /* Compute available bandwidth (kHz) */ + totalbw = dpbw * lanecount * 270000 * 8 / 10; + + /* Required bandwidth (8 bpc, kHz) */ + requiredbw = mode->clock * 8 * 3; + + DRM_DEBUG_KMS("DP bandwidth: %d kHz (%02x/%d); mode requires %d Khz\n", + totalbw, dpbw, lanecount, requiredbw); + + if (totalbw == 0) { + DRM_ERROR("Bandwidth/lane count are 0, not rejecting modes\n"); + return true; + } + + return totalbw >= requiredbw; +} + +static const struct drm_bridge_funcs cros_ec_anx7688_bridge_funcs = { + .mode_fixup = cros_ec_anx7688_bridge_mode_fixup, +}; + +static int cros_ec_anx7688_bridge_probe(struct i2c_client *client) +{ + struct device *dev = &client->dev; + struct cros_ec_anx7688 *anx7688; + u16 vendor, device, fw_version; + u8 buffer[4]; + int ret; + + anx7688 = devm_kzalloc(dev, sizeof(*anx7688), GFP_KERNEL); + if (!anx7688) + return -ENOMEM; + + anx7688->client = client; + i2c_set_clientdata(client, anx7688); + + anx7688->regmap = devm_regmap_init_i2c(client, &cros_ec_anx7688_regmap_config); + if (IS_ERR(anx7688->regmap)) { + ret = PTR_ERR(anx7688->regmap); + dev_err(dev, "regmap i2c init failed: %d\n", ret); + return ret; + } + + /* Read both vendor and device id (4 bytes). */ + ret = regmap_bulk_read(anx7688->regmap, ANX7688_VENDOR_ID_REG, + buffer, 4); + if (ret) { + dev_err(dev, "Failed to read chip vendor/device id\n"); + return ret; + } + + vendor = (u16)buffer[1] << 8 | buffer[0]; + device = (u16)buffer[3] << 8 | buffer[2]; + if (vendor != ANX7688_VENDOR_ID || device != ANX7688_DEVICE_ID) { + dev_err(dev, "Invalid vendor/device id %04x/%04x\n", + vendor, device); + return -ENODEV; + } + + ret = regmap_bulk_read(anx7688->regmap, ANX7688_FW_VERSION_REG, + buffer, 2); + if (ret) { + dev_err(dev, "Failed to read firmware version\n"); + return ret; + } + + fw_version = (u16)buffer[0] << 8 | buffer[1]; + dev_info(dev, "ANX7688 firmware version 0x%04x\n", fw_version); + + anx7688->bridge.of_node = dev->of_node; + + /* FW version >= 0.85 supports bandwidth/lane count registers */ + if (fw_version >= ANX7688_MINIMUM_FW_VERSION) + anx7688->filter = true; + else + /* Warn, but not fail, for backwards compatibility */ + DRM_WARN("Old ANX7688 FW version (0x%04x), not filtering\n", + fw_version); + + anx7688->bridge.funcs = &cros_ec_anx7688_bridge_funcs; + drm_bridge_add(&anx7688->bridge); + + return 0; +} + +static int cros_ec_anx7688_bridge_remove(struct i2c_client *client) +{ + struct cros_ec_anx7688 *anx7688 = i2c_get_clientdata(client); + + drm_bridge_remove(&anx7688->bridge); + + return 0; +} + +static const struct of_device_id cros_ec_anx7688_bridge_match_table[] = { + { .compatible = "google,cros-ec-anx7688" }, + { } +}; +MODULE_DEVICE_TABLE(of, cros_ec_anx7688_bridge_match_table); + +static struct i2c_driver cros_ec_anx7688_bridge_driver = { + .probe_new = cros_ec_anx7688_bridge_probe, + .remove = cros_ec_anx7688_bridge_remove, + .driver = { + .name = "cros-ec-anx7688-bridge", + .of_match_table = cros_ec_anx7688_bridge_match_table, + }, +}; + +module_i2c_driver(cros_ec_anx7688_bridge_driver); + +MODULE_DESCRIPTION("ChromeOS EC ANX7688 HDMI->DP bridge driver"); +MODULE_AUTHOR("Nicolas Boichat "); +MODULE_AUTHOR("Enric Balletbo i Serra "); +MODULE_LICENSE("GPL");