From patchwork Tue Jul 25 20:34:43 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Doug Anderson X-Patchwork-Id: 706781 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1D5D2C41513 for ; Tue, 25 Jul 2023 20:37:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231230AbjGYUht (ORCPT ); Tue, 25 Jul 2023 16:37:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35184 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231462AbjGYUhb (ORCPT ); Tue, 25 Jul 2023 16:37:31 -0400 Received: from mail-pg1-x529.google.com (mail-pg1-x529.google.com [IPv6:2607:f8b0:4864:20::529]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EB0182704 for ; Tue, 25 Jul 2023 13:37:15 -0700 (PDT) Received: by mail-pg1-x529.google.com with SMTP id 41be03b00d2f7-53482b44007so3064443a12.2 for ; Tue, 25 Jul 2023 13:37:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1690317434; x=1690922234; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=pLU4GaCp6ltBfg0ajT8nW3f7rOZfzJGhG7FU81YHMIc=; b=StVSDcWMfA7TJ+Wp3D7IahafFoAoSFplzVN3xvyQE3lKGASTqWpuH7liiDVdA661// WuvraSDsXCp7t3Br6Kq5LtSw/2aZc6JKry7bt58S2lBkYmUsVT/WKJ8Mb07wK+vzu5w/ vsG0HJJ0OrAU9h8RTO+aWvKhNSPxWSxcQrrdU= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1690317434; x=1690922234; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=pLU4GaCp6ltBfg0ajT8nW3f7rOZfzJGhG7FU81YHMIc=; b=U/r+h4rPL/mo2+JdE/It2r8PRuhVA4xqtrF/smxGh59LqU1rJBfC/5CKBbcF/gl1AA Drr6sUuGa/Xu0X7MGs00qAOWjVR1mLWTnkVC/LUzs4EAqwGm4K2BLhp7CCSNxuLhVJ1l LpY9js2IOvGBuBM1ghcSEfRuUngYoV1r9QNpi+uV0fiS3HGzfAUn6t8nHjnU7EUHPR6e wAb5CiCyHJW14nyr3bSBnyv5WXc5mpJe4mU34vcUEj9dwjLBa1TBP/0TSpzB9xfy5AJ0 ToENoE4SF3Z4qqBwRGnRymFvjzvl2Jf8jBqvv9uOj5HgPf0x5NSwtqH7/ycqq/FqIV98 sLaQ== X-Gm-Message-State: ABy/qLbb99EzcTNopmgBJWIUsoU625MZKufdp2FnE/MMOlqOiceVSIgB NTEslFfQ2bc7BNhkyMsnCBlYsQ== X-Google-Smtp-Source: APBJJlEfktDwpmXEzqrjjxC7Zx3JDhTxoTfUhGnVB/nI7JJ8QBFQehaWlH32omPSIBQuWifk0WXkYg== X-Received: by 2002:a17:90a:c08:b0:267:6ea5:61dd with SMTP id 8-20020a17090a0c0800b002676ea561ddmr222775pjs.15.1690317434661; Tue, 25 Jul 2023 13:37:14 -0700 (PDT) Received: from tictac2.mtv.corp.google.com ([2620:15c:9d:2:c363:4681:f5b8:301]) by smtp.gmail.com with ESMTPSA id bg1-20020a17090b0d8100b002676e961261sm1396951pjb.1.2023.07.25.13.37.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 25 Jul 2023 13:37:14 -0700 (PDT) From: Douglas Anderson To: Jiri Kosina , Benjamin Tissoires , Bjorn Andersson , Konrad Dybcio , Rob Herring , Frank Rowand , Krzysztof Kozlowski , Conor Dooley , Neil Armstrong , Sam Ravnborg , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann Cc: cros-qcom-dts-watchers@chromium.org, Chris Morgan , linux-input@vger.kernel.org, hsinyi@google.com, linux-arm-msm@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Dmitry Torokhov , devicetree@vger.kernel.org, Daniel Vetter , yangcong5@huaqin.corp-partner.google.com, Douglas Anderson Subject: [PATCH v3 08/10] HID: i2c-hid: Support being a panel follower Date: Tue, 25 Jul 2023 13:34:43 -0700 Message-ID: <20230725133443.v3.8.Ib1a98309c455cd7e26b931c69993d4fba33bbe15@changeid> X-Mailer: git-send-email 2.41.0.487.g6d72f3e995-goog In-Reply-To: <20230725203545.2260506-1-dianders@chromium.org> References: <20230725203545.2260506-1-dianders@chromium.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org As talked about in the patch ("drm/panel: Add a way for other devices to follow panel state"), we really want to keep the power states of a touchscreen and the panel it's attached to in sync with each other. In that spirit, add support to i2c-hid to be a panel follower. This will let the i2c-hid driver get informed when the panel is powered on and off. From there we can match the i2c-hid device's power state to that of the panel. NOTE: this patch specifically _doesn't_ use pm_runtime to keep track of / manage the power state of the i2c-hid device, even though my first instinct said that would be the way to go. Specific problems with using pm_runtime(): * The initial power up couldn't happen in a runtime resume function since it create sub-devices and, apparently, that's not good to do in your resume function. * Managing our power state with pm_runtime meant fighting to make the right thing happen at system suspend to prevent the system from trying to resume us only to suspend us again. While this might be able to be solved, it added complexity. Overall the code without pm_runtime() ended up being smaller and easier to understand. Signed-off-by: Douglas Anderson --- Changes in v3: - Add "depends on DRM || !DRM" to Kconfig to avoid randconfig error. - Split more of the panel follower code out of the core. Changes in v2: - i2c_hid_core_panel_prepared() and ..._unpreparing() are now static. drivers/hid/i2c-hid/Kconfig | 2 + drivers/hid/i2c-hid/i2c-hid-core.c | 82 +++++++++++++++++++++++++++++- 2 files changed, 82 insertions(+), 2 deletions(-) diff --git a/drivers/hid/i2c-hid/Kconfig b/drivers/hid/i2c-hid/Kconfig index 3be17109301a..2bdb55203104 100644 --- a/drivers/hid/i2c-hid/Kconfig +++ b/drivers/hid/i2c-hid/Kconfig @@ -70,5 +70,7 @@ config I2C_HID_OF_GOODIX config I2C_HID_CORE tristate + # We need to call into panel code so if DRM=m, this can't be 'y' + depends on DRM || !DRM endif diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c index fa8a1ca43d7f..fa6d1f624342 100644 --- a/drivers/hid/i2c-hid/i2c-hid-core.c +++ b/drivers/hid/i2c-hid/i2c-hid-core.c @@ -38,6 +38,8 @@ #include #include +#include + #include "../hid-ids.h" #include "i2c-hid.h" @@ -107,6 +109,8 @@ struct i2c_hid { struct mutex reset_lock; struct i2chid_ops *ops; + struct drm_panel_follower panel_follower; + bool is_panel_follower; }; static const struct i2c_hid_quirks { @@ -1058,6 +1062,59 @@ static int i2c_hid_core_initial_power_up(struct i2c_hid *ihid) return ret; } +static int i2c_hid_core_panel_prepared(struct drm_panel_follower *follower) +{ + struct i2c_hid *ihid = container_of(follower, struct i2c_hid, panel_follower); + struct hid_device *hid = ihid->hid; + + /* + * hid->version is set on the first power up. If it's still zero then + * this is the first power on so we should perform initial power up + * steps. + */ + if (!hid->version) + return i2c_hid_core_initial_power_up(ihid); + + return i2c_hid_core_resume(ihid); +} + +static int i2c_hid_core_panel_unpreparing(struct drm_panel_follower *follower) +{ + struct i2c_hid *ihid = container_of(follower, struct i2c_hid, panel_follower); + + return i2c_hid_core_suspend(ihid); +} + +static const struct drm_panel_follower_funcs i2c_hid_core_panel_follower_funcs = { + .panel_prepared = i2c_hid_core_panel_prepared, + .panel_unpreparing = i2c_hid_core_panel_unpreparing, +}; + +static int i2c_hid_core_register_panel_follower(struct i2c_hid *ihid) +{ + struct device *dev = &ihid->client->dev; + int ret; + + ihid->is_panel_follower = true; + ihid->panel_follower.funcs = &i2c_hid_core_panel_follower_funcs; + + /* + * If we're not in control of our own power up/power down then we can't + * do the logic to manage wakeups. Give a warning if a user thought + * that was possible then force the capability off. + */ + if (device_can_wakeup(dev)) { + dev_warn(dev, "Can't wakeup if following panel\n"); + device_set_wakeup_capable(dev, false); + } + + ret = drm_panel_add_follower(dev, &ihid->panel_follower); + if (ret) + return ret; + + return 0; +} + int i2c_hid_core_probe(struct i2c_client *client, struct i2chid_ops *ops, u16 hid_descriptor_address, u32 quirks) { @@ -1119,7 +1176,15 @@ int i2c_hid_core_probe(struct i2c_client *client, struct i2chid_ops *ops, hid->bus = BUS_I2C; hid->initial_quirks = quirks; - ret = i2c_hid_core_initial_power_up(ihid); + /* + * If we're a panel follower, we'll register and do our initial power + * up when the panel turns on; otherwise we do it right away. + */ + if (drm_is_panel_follower(&client->dev)) + ret = i2c_hid_core_register_panel_follower(ihid); + else + ret = i2c_hid_core_initial_power_up(ihid); + if (ret) goto err_mem_free; @@ -1143,7 +1208,14 @@ void i2c_hid_core_remove(struct i2c_client *client) struct i2c_hid *ihid = i2c_get_clientdata(client); struct hid_device *hid; - i2c_hid_core_power_down(ihid); + /* + * If we're a follower, the act of unfollowing will cause us to be + * powered down. Otherwise we need to manually do it. + */ + if (ihid->is_panel_follower) + drm_panel_remove_follower(&ihid->panel_follower); + else + i2c_hid_core_power_down(ihid); hid = ihid->hid; hid_destroy_device(hid); @@ -1171,6 +1243,9 @@ static int i2c_hid_core_pm_suspend(struct device *dev) struct i2c_client *client = to_i2c_client(dev); struct i2c_hid *ihid = i2c_get_clientdata(client); + if (ihid->is_panel_follower) + return 0; + return i2c_hid_core_suspend(ihid); } @@ -1179,6 +1254,9 @@ static int i2c_hid_core_pm_resume(struct device *dev) struct i2c_client *client = to_i2c_client(dev); struct i2c_hid *ihid = i2c_get_clientdata(client); + if (ihid->is_panel_follower) + return 0; + return i2c_hid_core_resume(ihid); }