From patchwork Fri Oct 9 08:11:00 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Coiby Xu X-Patchwork-Id: 11825379 X-Patchwork-Delegate: jikos@jikos.cz Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 992FF1592 for ; Fri, 9 Oct 2020 08:11:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6FBC8221FC for ; Fri, 9 Oct 2020 08:11:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="T2V/ftxC" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732451AbgJIILL (ORCPT ); Fri, 9 Oct 2020 04:11:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51350 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732337AbgJIILK (ORCPT ); Fri, 9 Oct 2020 04:11:10 -0400 Received: from mail-pl1-x644.google.com (mail-pl1-x644.google.com [IPv6:2607:f8b0:4864:20::644]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2555BC0613D2; Fri, 9 Oct 2020 01:11:09 -0700 (PDT) Received: by mail-pl1-x644.google.com with SMTP id d6so4079459plo.13; Fri, 09 Oct 2020 01:11:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=vkCv+bp/FrfI2HKWKx1Tww6cQhDH3EWEn1gwkV8Cg1I=; b=T2V/ftxCmwcqj8mOsikkMgN9z4zZoUidPnfRwe42UDq05MXXofRSl69ii78YryxkaI NFe5rzQuamr1/PPX/MXet7xMS8iWJYfr8CtLsIdL0XEgltd7fVr5ndUI32Dr/hgqrylV SgnISJqsGeYp1i4A8rUxITf/UkCkM+lRuWfsU4ea04l9fzN5jN4MLU/N8XRJ575ufNgI pcFf/7KxTjn7PfpGZtQupy65qIGbXKvB19BSGSijSAiEsxnfXSqs85eDdN0bqtP+vILs ZWe2/NeYs6ICotIvHJoh4a44bFy4tQxvOUy94dkT0xBhU+Un4Xzwym6i44a7207ubhRo ROIA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=vkCv+bp/FrfI2HKWKx1Tww6cQhDH3EWEn1gwkV8Cg1I=; b=J0DIH+oPsJXkQEGT0LuGD4fBK5eDEqDvjtgOHpHdJKnzz4Ykn/Jhm7QJw2XDeoEBQg bGaQixxweSxTVRO4TUPIiFZNbATDHO3FzcSOht9tE4tHBkimLUwNuWu8PyHbFpFoF4I4 fh6PcPGoKJFxv8k3i97LSm2Szu7OYlopXzY7WjI3w+a9O1TDoy2iHw+0Gw6TBhZ8By7s TUiC+FvGO3jb5fhj9iRheJvOEQSasj8atk3jYHTkvpM0REPuOMnuKOBKqxi8adBqVQZc 1tEP6sgtIrAm14DZ/yVNpys6coktGpB3rM6Di0cO1NbCfls8rwgBjGjE/AeXEqjVe+MD 8Z0g== X-Gm-Message-State: AOAM531zVyrE0nSNt8m2cSIHOsdFQuicViTZAi+O1ocSwBjzTgpmJuYw RxN6d73XuXykmVL+syqbqi7PnpTf1l5WN2i/ X-Google-Smtp-Source: ABdhPJxvIIE97qi/nL7QdFuS79SJh9C4Jdjr4dbIHvuca7vf0rsfz7InDmd7Iw+PDMRiulJevRqLzA== X-Received: by 2002:a17:902:bf4b:b029:d1:e5e7:bddd with SMTP id u11-20020a170902bf4bb02900d1e5e7bdddmr10979173pls.61.1602231068306; Fri, 09 Oct 2020 01:11:08 -0700 (PDT) Received: from localhost ([2001:e42:102:1532:160:16:113:140]) by smtp.gmail.com with ESMTPSA id c9sm9531637pgl.92.2020.10.09.01.11.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 09 Oct 2020 01:11:07 -0700 (PDT) From: Coiby Xu To: linux-input@vger.kernel.org Cc: Jiri Kosina , Benjamin Tissoires , linux-kernel@vger.kernel.org (open list) Subject: [PATCH] HID: i2c-hid: add polling mode based on connected GPIO chip's pin status Date: Fri, 9 Oct 2020 16:11:00 +0800 Message-Id: <20201009081100.3154-1-coiby.xu@gmail.com> X-Mailer: git-send-email 2.28.0 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org For a broken touchpad, it may take several months or longer to be fixed. Polling mode could be a fallback solution for enthusiastic Linux users when they have a new laptop. It also acts like a debugging feature. If polling mode works for a broken touchpad, we can almost be certain the root cause is related to the interrupt. Two module parameters are added to i2c-hid, - polling_mode: by default set to 0, i.e., polling is disabled - polling_interval (ms): user can change this runtime parameter by writing to /sys/module/i2c_hid/parameters/polling_interval Signed-off-by: Coiby Xu --- drivers/hid/i2c-hid/i2c-hid-core.c | 127 +++++++++++++++++++++++++++-- 1 file changed, 119 insertions(+), 8 deletions(-) -- 2.28.0 diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c index dbd04492825d..c7af127959f6 100644 --- a/drivers/hid/i2c-hid/i2c-hid-core.c +++ b/drivers/hid/i2c-hid/i2c-hid-core.c @@ -36,6 +36,8 @@ #include #include #include +#include +#include #include #include @@ -60,6 +62,18 @@ #define I2C_HID_PWR_ON 0x00 #define I2C_HID_PWR_SLEEP 0x01 +/* polling mode */ +#define I2C_POLLING_DISABLED 0 +#define I2C_POLLING_GPIO_PIN 1 +#define POLLING_INTERVAL 10 + +static u8 polling_mode; +module_param(polling_mode, byte, 0444); +MODULE_PARM_DESC(polling_mode, "How to poll - 0 disabled; 1 based on GPIO pin's status"); + +static unsigned int polling_interval = 10; +module_param(polling_interval, uint, 0644); +MODULE_PARM_DESC(polling_interval, "Poll every {polling_interval} ms. Default to 10 ms"); /* debug option */ static bool debug; module_param(debug, bool, 0444); @@ -158,6 +172,8 @@ struct i2c_hid { struct i2c_hid_platform_data pdata; + struct task_struct *polling_thread; + bool irq_wake_enabled; struct mutex reset_lock; }; @@ -772,7 +788,9 @@ static int i2c_hid_start(struct hid_device *hid) i2c_hid_free_buffers(ihid); ret = i2c_hid_alloc_buffers(ihid, bufsize); - enable_irq(client->irq); + + if (polling_mode == I2C_POLLING_DISABLED) + enable_irq(client->irq); if (ret) return ret; @@ -814,6 +832,83 @@ struct hid_ll_driver i2c_hid_ll_driver = { }; EXPORT_SYMBOL_GPL(i2c_hid_ll_driver); +static int get_gpio_pin_state(struct irq_desc *irq_desc) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(&irq_desc->irq_data); + + return gc->get(gc, irq_desc->irq_data.hwirq); +} + +static bool interrupt_line_active(struct i2c_client *client) +{ + unsigned long trigger_type = irq_get_trigger_type(client->irq); + struct irq_desc *irq_desc = irq_to_desc(client->irq); + + /* + * According to Windows Precsiontion Touchpad's specs + * https://docs.microsoft.com/en-us/windows-hardware/design/component-guidelines/windows-precision-touchpad-device-bus-connectivity, + * GPIO Interrupt Assertion Leve could be either ActiveLow or + * ActiveHigh. + */ + if (trigger_type & IRQF_TRIGGER_LOW) + return !get_gpio_pin_state(irq_desc); + + return get_gpio_pin_state(irq_desc); +} + +static int i2c_hid_polling_thread(void *i2c_hid) +{ + struct i2c_hid *ihid = i2c_hid; + struct i2c_client *client = ihid->client; + unsigned int polling_interval_ms; + + while (1) { + polling_interval_ms = polling_interval*1000; + if (test_bit(I2C_HID_READ_PENDING, &ihid->flags)) + usleep_range(50000, 100000); + + if (kthread_should_stop()) + break; + + while (interrupt_line_active(client)) { + i2c_hid_get_input(ihid); + /* + * keeping polling for new data at a rate of ~200Hz + * until the interrupt line becomes inactive + */ + usleep_range(4000, 6000); + } + + usleep_range(polling_interval_ms, polling_interval_ms); + } + + do_exit(0); + return 0; +} + +static int i2c_hid_init_polling(struct i2c_hid *ihid) +{ + struct i2c_client *client = ihid->client; + + if (!irq_get_trigger_type(client->irq)) { + dev_warn(&client->dev, + "Failed to get GPIO Interrupt Assertion Level, could not enable polling mode for %s", + client->name); + return -1; + } + + ihid->polling_thread = kthread_create(i2c_hid_polling_thread, ihid, + "I2C HID polling thread"); + + if (ihid->polling_thread) { + pr_info("I2C HID polling thread"); + wake_up_process(ihid->polling_thread); + return 0; + } + + return -1; +} + static int i2c_hid_init_irq(struct i2c_client *client) { struct i2c_hid *ihid = i2c_get_clientdata(client); @@ -997,6 +1092,16 @@ static void i2c_hid_fwnode_probe(struct i2c_client *client, pdata->post_power_delay_ms = val; } +static void free_irq_or_stop_polling(struct i2c_client *client, + struct i2c_hid *ihid) +{ + + if (polling_mode != I2C_POLLING_DISABLED) + kthread_stop(ihid->polling_thread); + else + free_irq(client->irq, ihid); +} + static int i2c_hid_probe(struct i2c_client *client, const struct i2c_device_id *dev_id) { @@ -1090,7 +1195,11 @@ static int i2c_hid_probe(struct i2c_client *client, if (ret < 0) goto err_regulator; - ret = i2c_hid_init_irq(client); + if (polling_mode != I2C_POLLING_DISABLED) + ret = i2c_hid_init_polling(ihid); + else + ret = i2c_hid_init_irq(client); + if (ret < 0) goto err_regulator; @@ -1129,7 +1238,7 @@ static int i2c_hid_probe(struct i2c_client *client, hid_destroy_device(hid); err_irq: - free_irq(client->irq, ihid); + free_irq_or_stop_polling(client, ihid); err_regulator: regulator_bulk_disable(ARRAY_SIZE(ihid->pdata.supplies), @@ -1146,7 +1255,7 @@ static int i2c_hid_remove(struct i2c_client *client) hid = ihid->hid; hid_destroy_device(hid); - free_irq(client->irq, ihid); + free_irq_or_stop_polling(client, ihid); if (ihid->bufsize) i2c_hid_free_buffers(ihid); @@ -1162,7 +1271,7 @@ static void i2c_hid_shutdown(struct i2c_client *client) struct i2c_hid *ihid = i2c_get_clientdata(client); i2c_hid_set_power(client, I2C_HID_PWR_SLEEP); - free_irq(client->irq, ihid); + free_irq_or_stop_polling(client, ihid); } #ifdef CONFIG_PM_SLEEP @@ -1183,7 +1292,8 @@ static int i2c_hid_suspend(struct device *dev) /* Save some power */ i2c_hid_set_power(client, I2C_HID_PWR_SLEEP); - disable_irq(client->irq); + if (polling_mode == I2C_POLLING_DISABLED) + disable_irq(client->irq); if (device_may_wakeup(&client->dev)) { wake_status = enable_irq_wake(client->irq); @@ -1216,7 +1326,7 @@ static int i2c_hid_resume(struct device *dev) if (ihid->pdata.post_power_delay_ms) msleep(ihid->pdata.post_power_delay_ms); - } else if (ihid->irq_wake_enabled) { + } else if (ihid->irq_wake_enabled && polling_mode != I2C_POLLING_DISABLED) { wake_status = disable_irq_wake(client->irq); if (!wake_status) ihid->irq_wake_enabled = false; @@ -1225,7 +1335,8 @@ static int i2c_hid_resume(struct device *dev) wake_status); } - enable_irq(client->irq); + if (polling_mode != I2C_POLLING_DISABLED) + enable_irq(client->irq); /* Instead of resetting device, simply powers the device on. This * solves "incomplete reports" on Raydium devices 2386:3118 and