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=-6.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 D171BC2BA83 for ; Fri, 14 Feb 2020 13:30:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9C184222C4 for ; Fri, 14 Feb 2020 13:30:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="Y/baTSTU" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729305AbgBNNaB (ORCPT ); Fri, 14 Feb 2020 08:30:01 -0500 Received: from mail-qt1-f196.google.com ([209.85.160.196]:43838 "EHLO mail-qt1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728036AbgBNNaB (ORCPT ); Fri, 14 Feb 2020 08:30:01 -0500 Received: by mail-qt1-f196.google.com with SMTP id d18so6923066qtj.10 for ; Fri, 14 Feb 2020 05:30:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=WczbSpdMfBJudZ25Ddor05iTOTahCwUaq+Ka7MWgDgo=; b=Y/baTSTUkEFUsoByjUmrmIuaruzpBzlRmHAY0gw/CZP40CMzbhb1h4MaWlbRoUNIg+ tsJwhVyGRNxJQj5gAq9Soz9xnWD0F5o58c5KVK+tZwdQL3M6/07iWk71Tyrecut7bSzS pTzpUdlHpSOqgNBKyo1FwMkysPw1f71Y0TWuY= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=WczbSpdMfBJudZ25Ddor05iTOTahCwUaq+Ka7MWgDgo=; b=FdOc0M7vJECWHBzQJRg1iac8047Xy72F9O4uEF5TJX2/VyBwD+AL4eMVTqfhaK7ZnG bBAZDa5C4eOrqhQNp/C47yu/LTozqUEyIKDozl7QusMEnEOqPQQJ+i6RedMeLed7UYJ4 glX1HVwaqLt91Ds2HYSsuUYLpi7H4DHUORYI/vxUokNxBLJyuPCGgp1uMMofXprBDyoH OJ2jowFIqdL2lOUrERrhFwtZwKBFh0mTJTMemTq7KzTdCwtRMGksNWIaIo/ezyIINgTz WbTCYe45uTX5LTFm2qsQGsiLRioR6uRQO/T+aQ+4yFiiCXeGwYHRQ4rZh9xJP3OyxAif d6QA== X-Gm-Message-State: APjAAAWO4uJ+K6fF1E48Kw+sDMbzz6NWPfdcMWJgAFuy8J10HdKg1m67 y4MAVwSalOKL/mb4UcriuTlA5GJ8/yLaBK0o0DgY3w== X-Google-Smtp-Source: APXvYqzOLiAo73evg90fCi05XKAW9KgBcfZPjTdJ6nVoVMYgc4iaiAThbdNcysh7XXibk0LYb7hCQOSGzyPtnIv1Vrg= X-Received: by 2002:ac8:4446:: with SMTP id m6mr2544214qtn.159.1581686999672; Fri, 14 Feb 2020 05:29:59 -0800 (PST) MIME-Version: 1.0 References: <20200213145416.890080-1-enric.balletbo@collabora.com> <20200213145416.890080-2-enric.balletbo@collabora.com> <6ed3c044-3573-35d4-ff17-7a40c83ac3af@samsung.com> In-Reply-To: <6ed3c044-3573-35d4-ff17-7a40c83ac3af@samsung.com> From: Nicolas Boichat Date: Fri, 14 Feb 2020 21:29:48 +0800 Message-ID: Subject: Re: [PATCH v2 2/2] drm/bridge: anx7688: Add anx7688 bridge driver support To: Andrzej Hajda Cc: Enric Balletbo i Serra , lkml , Jernej Skrabec , Laurent Pinchart , Neil Armstrong , David Airlie , Torsten Duwe , Jonas Karlman , dri-devel , Vasily Khoruzhick , Maxime Ripard , Hsin-Yi Wang , Matthias Brugger , Thomas Gleixner , Collabora Kernel ML , Icenowy Zheng Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 14, 2020 at 8:18 PM Andrzej Hajda wrote: > > On 13.02.2020 15:54, Enric Balletbo i Serra wrote: > > From: Nicolas Boichat > > > > ANX7688 is a HDMI to DP converter (as well as USB-C port controller), > > that has an internal microcontroller. > > > > The only reason a 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 on I2C. > > > > Signed-off-by: Nicolas Boichat > > Signed-off-by: Hsin-Yi Wang > > Signed-off-by: Enric Balletbo i Serra > > --- > > > > Changes in v2: > > - Move driver to drivers/gpu/drm/bridge/analogix. > > - Make the driver OF only so we can reduce the ifdefs. > > - Update the Copyright to 2020. > > - Use probe_new so we can get rid of the i2c_device_id table. > > > > drivers/gpu/drm/bridge/analogix/Kconfig | 12 ++ > > drivers/gpu/drm/bridge/analogix/Makefile | 1 + > > .../drm/bridge/analogix/analogix-anx7688.c | 188 ++++++++++++++++++ > > 3 files changed, 201 insertions(+) > > create mode 100644 drivers/gpu/drm/bridge/analogix/analogix-anx7688.c > > > > diff --git a/drivers/gpu/drm/bridge/analogix/Kconfig b/drivers/gpu/drm/bridge/analogix/Kconfig > > index e1fa7d820373..af7c2939403c 100644 > > --- a/drivers/gpu/drm/bridge/analogix/Kconfig > > +++ b/drivers/gpu/drm/bridge/analogix/Kconfig > > @@ -11,6 +11,18 @@ config DRM_ANALOGIX_ANX6345 > > ANX6345 transforms the LVTTL RGB output of an > > application processor to eDP or DisplayPort. > > > > +config DRM_ANALOGIX_ANX7688 > > + tristate "Analogix ANX7688 bridge" > > + depends on OF > > + select DRM_KMS_HELPER > > + select REGMAP_I2C > > + help > > + ANX7688 is an ultra-low power 4k Ultra-HD (4096x2160p60) > > + mobile HD transmitter designed for portable devices. The > > + ANX7688 converts HDMI 2.0 to DisplayPort 1.3 Ultra-HD > > + including an intelligent crosspoint switch to support > > + USB Type-C. > > + > > config DRM_ANALOGIX_ANX78XX > > tristate "Analogix ANX78XX bridge" > > select DRM_ANALOGIX_DP > > diff --git a/drivers/gpu/drm/bridge/analogix/Makefile b/drivers/gpu/drm/bridge/analogix/Makefile > > index 97669b374098..27cd73635c8c 100644 > > --- a/drivers/gpu/drm/bridge/analogix/Makefile > > +++ b/drivers/gpu/drm/bridge/analogix/Makefile > > @@ -1,5 +1,6 @@ > > # SPDX-License-Identifier: GPL-2.0-only > > analogix_dp-objs := analogix_dp_core.o analogix_dp_reg.o analogix-i2c-dptx.o > > obj-$(CONFIG_DRM_ANALOGIX_ANX6345) += analogix-anx6345.o > > +obj-$(CONFIG_DRM_ANALOGIX_ANX7688) += analogix-anx7688.o > > obj-$(CONFIG_DRM_ANALOGIX_ANX78XX) += analogix-anx78xx.o > > obj-$(CONFIG_DRM_ANALOGIX_DP) += analogix_dp.o > > diff --git a/drivers/gpu/drm/bridge/analogix/analogix-anx7688.c b/drivers/gpu/drm/bridge/analogix/analogix-anx7688.c > > new file mode 100644 > > index 000000000000..10a7cd0f9126 > > --- /dev/null > > +++ b/drivers/gpu/drm/bridge/analogix/analogix-anx7688.c > > @@ -0,0 +1,188 @@ > > +// SPDX-License-Identifier: GPL-2.0-only > > +/* > > + * ANX7688 HDMI->DP bridge driver > > + * > > + * Copyright 2020 Google LLC > > + */ > > + > > +#include > > +#include > > +#include > > +#include > > + > > +/* Register addresses */ > > +#define VENDOR_ID_REG 0x00 > > +#define DEVICE_ID_REG 0x02 > > + > > +#define FW_VERSION_REG 0x80 > > + > > +#define DP_BANDWIDTH_REG 0x85 > > +#define DP_LANE_COUNT_REG 0x86 > > + > > +#define VENDOR_ID 0x1f29 > > +#define DEVICE_ID 0x7688 > > + > > +/* First supported firmware version (0.85) */ > > +#define MINIMUM_FW_VERSION 0x0085 > > + > > +struct anx7688 { > > + struct drm_bridge bridge; > > + struct i2c_client *client; > > + struct regmap *regmap; > > + > > + bool filter; > > +}; > > + > > +static inline struct anx7688 *bridge_to_anx7688(struct drm_bridge *bridge) > > +{ > > + return container_of(bridge, struct anx7688, bridge); > > +} > > + > > +static bool anx7688_bridge_mode_fixup(struct drm_bridge *bridge, > > + const struct drm_display_mode *mode, > > + struct drm_display_mode *adjusted_mode) > > +{ > > + struct anx7688 *anx7688 = bridge_to_anx7688(bridge); > > + int totalbw, requiredbw; > > + u8 dpbw, lanecount; > > + u8 regs[2]; > > + int ret; > > + > > + if (!anx7688->filter) > > + return true; > > + > > + /* Read both regs 0x85 (bandwidth) and 0x86 (lane count). */ > > + ret = regmap_bulk_read(anx7688->regmap, DP_BANDWIDTH_REG, regs, 2); > > + if (ret < 0) { > > + dev_err(&anx7688->client->dev, > > + "Failed to read bandwidth/lane count\n"); > > + return false; > > + } > > + dpbw = regs[0]; > > + lanecount = regs[1]; > > > Are these values hw invariant? Or they are result of cable probe/training? > > In 1st case this code should go rather to mode_valid. 2nd case. They're the result of probing/training of the DP link: number of lanes (1 or 2), and bandwidth (RBR, HBR, HBR2...). > > + > > + /* Maximum 0x19 bandwidth (6.75 Gbps Turbo mode), 2 lanes */ > > + if (dpbw > 0x19 || lanecount > 2) { > > + dev_err(&anx7688->client->dev, > > + "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; > > + > > + dev_dbg(&anx7688->client->dev, > > + "DP bandwidth: %d kHz (%02x/%d); mode requires %d Khz\n", > > + totalbw, dpbw, lanecount, requiredbw); > > + > > + if (totalbw == 0) { > > + dev_warn(&anx7688->client->dev, > > + "Bandwidth/lane count are 0, not rejecting modes\n"); > > + return true; > > + } > > + > > + return totalbw >= requiredbw; > > +} > > + > > +static const struct drm_bridge_funcs anx7688_bridge_funcs = { > > + .mode_fixup = anx7688_bridge_mode_fixup, > > +}; > > + > > +static const struct regmap_config anx7688_regmap_config = { > > + .reg_bits = 8, > > + .val_bits = 8, > > +}; > > + > > +static int anx7688_i2c_probe(struct i2c_client *client) > > +{ > > + struct device *dev = &client->dev; > > + struct anx7688 *anx7688; > > + u16 vendor, device; > > + u16 fwversion; > > + u8 buffer[4]; > > + int ret; > > + > > + anx7688 = devm_kzalloc(dev, sizeof(*anx7688), GFP_KERNEL); > > + if (!anx7688) > > + return -ENOMEM; > > + > > + anx7688->bridge.of_node = dev->of_node; > > + anx7688->client = client; > > + i2c_set_clientdata(client, anx7688); > > + > > + anx7688->regmap = devm_regmap_init_i2c(client, &anx7688_regmap_config); > > + > > + /* Read both vendor and device id (4 bytes). */ > > + ret = regmap_bulk_read(anx7688->regmap, 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]; > > > Here we have little endian, and... > > > > + if (vendor != VENDOR_ID || device != DEVICE_ID) { > > + dev_err(dev, "Invalid vendor/device id %04x/%04x\n", > > + vendor, device); > > + return -ENODEV; > > + } > > + > > + ret = regmap_bulk_read(anx7688->regmap, FW_VERSION_REG, buffer, 2); > > + if (ret) { > > + dev_err(&client->dev, "Failed to read firmware version\n"); > > + return ret; > > + } > > + > > + fwversion = (u16)buffer[0] << 8 | buffer[1]; > > > ...here big endian. > > Is it correct? > > > Overall driver looks OK. > > Reviewed-by: Andrzej Hajda > > -- > Regards > Andrzej > > > > + dev_info(dev, "ANX7688 firwmare version %02x.%02x\n", > > + buffer[0], buffer[1]); > > + > > + /* FW version >= 0.85 supports bandwidth/lane count registers */ > > + if (fwversion >= MINIMUM_FW_VERSION) { > > + anx7688->filter = true; > > + } else { > > + /* Warn, but not fail, for backwards compatibility. */ > > + dev_warn(dev, > > + "Old ANX7688 FW version (%02x.%02x), not filtering\n", > > + buffer[0], buffer[1]); > > + } > > + > > + anx7688->bridge.funcs = &anx7688_bridge_funcs; > > + drm_bridge_add(&anx7688->bridge); > > + > > + return 0; > > +} > > + > > +static int anx7688_i2c_remove(struct i2c_client *client) > > +{ > > + struct anx7688 *anx7688 = i2c_get_clientdata(client); > > + > > + drm_bridge_remove(&anx7688->bridge); > > + > > + return 0; > > +} > > + > > +static const struct of_device_id anx7688_match_table[] = { > > + { .compatible = "analogix,anx7688", }, > > + { } > > +}; > > +MODULE_DEVICE_TABLE(of, anx7688_match_table); > > + > > +static struct i2c_driver anx7688_driver = { > > + .probe_new = anx7688_i2c_probe, > > + .remove = anx7688_i2c_remove, > > + .driver = { > > + .name = "anx7688", > > + .of_match_table = anx7688_match_table, > > + }, > > +}; > > + > > +module_i2c_driver(anx7688_driver); > > + > > +MODULE_DESCRIPTION("ANX7688 HDMI->DP bridge driver"); > > +MODULE_AUTHOR("Nicolas Boichat "); > > +MODULE_LICENSE("GPL"); > >