From patchwork Mon Jan 26 12:15:26 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roger Quadros X-Patchwork-Id: 432731 Return-Path: X-Original-To: incoming-dt@patchwork.ozlabs.org Delivered-To: patchwork-incoming-dt@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id A30A4140185 for ; Mon, 26 Jan 2015 23:18:35 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754394AbbAZMPu (ORCPT ); Mon, 26 Jan 2015 07:15:50 -0500 Received: from comal.ext.ti.com ([198.47.26.152]:33782 "EHLO comal.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753925AbbAZMPq (ORCPT ); Mon, 26 Jan 2015 07:15:46 -0500 Received: from dlelxv90.itg.ti.com ([172.17.2.17]) by comal.ext.ti.com (8.13.7/8.13.7) with ESMTP id t0QCFfml017972; Mon, 26 Jan 2015 06:15:41 -0600 Received: from DFLE73.ent.ti.com (dfle73.ent.ti.com [128.247.5.110]) by dlelxv90.itg.ti.com (8.14.3/8.13.8) with ESMTP id t0QCFeEZ010719; Mon, 26 Jan 2015 06:15:40 -0600 Received: from dlep33.itg.ti.com (157.170.170.75) by DFLE73.ent.ti.com (128.247.5.110) with Microsoft SMTP Server id 14.3.224.2; Mon, 26 Jan 2015 06:15:40 -0600 Received: from rockdesk.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by dlep33.itg.ti.com (8.14.3/8.13.8) with ESMTP id t0QCFYI4021442; Mon, 26 Jan 2015 06:15:38 -0600 From: Roger Quadros To: , , , CC: , , , , , , Roger Quadros Subject: [PATCH v2 1/7] extcon: usb-gpio: Introduce gpio usb extcon driver Date: Mon, 26 Jan 2015 14:15:26 +0200 Message-ID: <1422274532-9488-2-git-send-email-rogerq@ti.com> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1422274532-9488-1-git-send-email-rogerq@ti.com> References: <1422274532-9488-1-git-send-email-rogerq@ti.com> MIME-Version: 1.0 Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org This driver observes the USB ID pin connected over a GPIO and updates the USB cable extcon states accordingly. The existing GPIO extcon driver is not suitable for this purpose as it needs to be taught to understand USB cable states and it can't handle more than one cable per instance. For the USB case we need to handle 2 cable states. 1) USB (attach/detach) 2) USB-Host (attach/detach) This driver can be easily updated in the future to handle VBUS events in case it happens to be available on GPIO for any platform. Signed-off-by: Roger Quadros --- .../devicetree/bindings/extcon/extcon-usb-gpio.txt | 20 ++ drivers/extcon/Kconfig | 7 + drivers/extcon/Makefile | 1 + drivers/extcon/extcon-usb-gpio.c | 214 +++++++++++++++++++++ 4 files changed, 242 insertions(+) create mode 100644 Documentation/devicetree/bindings/extcon/extcon-usb-gpio.txt create mode 100644 drivers/extcon/extcon-usb-gpio.c diff --git a/Documentation/devicetree/bindings/extcon/extcon-usb-gpio.txt b/Documentation/devicetree/bindings/extcon/extcon-usb-gpio.txt new file mode 100644 index 0000000..ab52a85 --- /dev/null +++ b/Documentation/devicetree/bindings/extcon/extcon-usb-gpio.txt @@ -0,0 +1,20 @@ +USB GPIO Extcon device + +This is a virtual device used to generate USB cable states from the USB ID pin +connected to a GPIO pin. + +Required properties: +- compatible: Should be "linux,extcon-usb-gpio" +- id-gpio: gpio for USB ID pin. See gpio binding. + +Example: + extcon_usb1 { + compatible = "linux,extcon-usb-gpio"; + id-gpio = <&gpio6 1 GPIO_ACTIVE_HIGH>; + } + + usb@1 { + ... + extcon = <&extcon_usb1>; + ... + }; diff --git a/drivers/extcon/Kconfig b/drivers/extcon/Kconfig index 6a1f7de..e4c01ab 100644 --- a/drivers/extcon/Kconfig +++ b/drivers/extcon/Kconfig @@ -93,4 +93,11 @@ config EXTCON_SM5502 Silicon Mitus SM5502. The SM5502 is a USB port accessory detector and switch. +config EXTCON_USB_GPIO + tristate "USB GPIO extcon support" + depends on GPIOLIB + help + Say Y here to enable GPIO based USB cable detection extcon support. + Used typically if GPIO is used for USB ID pin detection. + endif # MULTISTATE_SWITCH diff --git a/drivers/extcon/Makefile b/drivers/extcon/Makefile index 0370b42..6a08a98 100644 --- a/drivers/extcon/Makefile +++ b/drivers/extcon/Makefile @@ -12,3 +12,4 @@ obj-$(CONFIG_EXTCON_MAX8997) += extcon-max8997.o obj-$(CONFIG_EXTCON_PALMAS) += extcon-palmas.o obj-$(CONFIG_EXTCON_RT8973A) += extcon-rt8973a.o obj-$(CONFIG_EXTCON_SM5502) += extcon-sm5502.o +obj-$(CONFIG_EXTCON_USB_GPIO) += extcon-usb-gpio.o diff --git a/drivers/extcon/extcon-usb-gpio.c b/drivers/extcon/extcon-usb-gpio.c new file mode 100644 index 0000000..a20aa39 --- /dev/null +++ b/drivers/extcon/extcon-usb-gpio.c @@ -0,0 +1,214 @@ +/** + * drivers/extcon/extcon_usb_gpio.c - USB GPIO extcon driver + * + * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com + * Author: Roger Quadros + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define USB_GPIO_DEBOUNCE_MS 20 /* ms */ + +struct usb_extcon_info { + struct device *dev; + struct extcon_dev *edev; + + struct gpio_desc *id_gpiod; + int id_irq; + + unsigned long debounce_jiffies; + struct delayed_work wq_detcable; +}; + +/* List of detectable cables */ +enum { + EXTCON_CABLE_USB = 0, + EXTCON_CABLE_USB_HOST, + + EXTCON_CABLE_END, +}; + +static const char *usb_extcon_cable[] = { + [EXTCON_CABLE_USB] = "USB", + [EXTCON_CABLE_USB_HOST] = "USB-Host", + NULL, +}; + +static void usb_extcon_detect_cable(struct work_struct *work) +{ + int id; + struct usb_extcon_info *info; + + info = container_of(to_delayed_work(work), struct usb_extcon_info, + wq_detcable); + + /* check ID and update cable state */ + id = gpiod_get_value_cansleep(info->id_gpiod); + if (id) { + /* + * ID = 1 means USB HOST cable detached. + * As we don't have event for USB peripheral cable attached, + * we simulate USB peripheral attach here. + */ + extcon_set_cable_state(info->edev, + usb_extcon_cable[EXTCON_CABLE_USB_HOST], + false); + extcon_set_cable_state(info->edev, + usb_extcon_cable[EXTCON_CABLE_USB], + true); + } else { + /* + * ID = 0 means USB HOST cable attached. + * As we don't have event for USB peripheral cable detached, + * we simulate USB peripheral detach here. + */ + extcon_set_cable_state(info->edev, + usb_extcon_cable[EXTCON_CABLE_USB], + false); + extcon_set_cable_state(info->edev, + usb_extcon_cable[EXTCON_CABLE_USB_HOST], + true); + } +} + +static irqreturn_t usb_irq_handler(int irq, void *dev_id) +{ + struct usb_extcon_info *info = dev_id; + + queue_delayed_work(system_power_efficient_wq, &info->wq_detcable, + info->debounce_jiffies); + return IRQ_HANDLED; +} + +static int usb_extcon_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct device_node *np = dev->of_node; + struct usb_extcon_info *info; + int ret; + + if (!np) + return -EINVAL; + + info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL); + if (!info) + return -ENOMEM; + + info->dev = dev; + info->id_gpiod = devm_gpiod_get(&pdev->dev, "id"); + if (IS_ERR(info->id_gpiod)) { + dev_err(dev, "failed to get ID GPIO\n"); + return PTR_ERR(info->id_gpiod); + } + + ret = gpiod_set_debounce(info->id_gpiod, + USB_GPIO_DEBOUNCE_MS * 1000); + if (ret < 0) + info->debounce_jiffies = msecs_to_jiffies(USB_GPIO_DEBOUNCE_MS); + + INIT_DELAYED_WORK(&info->wq_detcable, usb_extcon_detect_cable); + + info->id_irq = gpiod_to_irq(info->id_gpiod); + if (info->id_irq < 0) { + dev_err(dev, "failed to get ID IRQ\n"); + return info->id_irq; + } + + ret = devm_request_threaded_irq(dev, info->id_irq, NULL, + usb_irq_handler, + IRQF_SHARED | IRQF_ONESHOT | + IRQF_NO_SUSPEND, + pdev->name, info); + if (ret < 0) { + dev_err(dev, "failed to request handler for ID IRQ\n"); + return ret; + } + + info->edev = devm_extcon_dev_allocate(dev, usb_extcon_cable); + if (IS_ERR(info->edev)) { + dev_err(dev, "failed to allocate extcon device\n"); + return -ENOMEM; + } + + ret = devm_extcon_dev_register(dev, info->edev); + if (ret < 0) { + dev_err(dev, "failed to register extcon device\n"); + return ret; + } + + platform_set_drvdata(pdev, info); + + /* Perform initial detection */ + usb_extcon_detect_cable(&info->wq_detcable.work); + + return 0; +} + +static int usb_extcon_remove(struct platform_device *pdev) +{ + struct usb_extcon_info *info = platform_get_drvdata(pdev); + + cancel_delayed_work_sync(&info->wq_detcable); + return 0; +} + +#ifdef CONFIG_PM_SLEEP +static int usb_extcon_suspend(struct device *dev) +{ + struct usb_extcon_info *info = dev_get_drvdata(dev); + + enable_irq_wake(info->id_irq); + return 0; +} + +static int usb_extcon_resume(struct device *dev) +{ + struct usb_extcon_info *info = dev_get_drvdata(dev); + + disable_irq_wake(info->id_irq); + return 0; +} +#endif + +static SIMPLE_DEV_PM_OPS(usb_extcon_pm_ops, + usb_extcon_suspend, usb_extcon_resume); + +static struct of_device_id usb_extcon_dt_match[] = { + { .compatible = "linux,extcon-usb-gpio", }, + { /* end */ } +}; +MODULE_DEVICE_TABLE(of, usb_extcon_dt_match); + +static struct platform_driver usb_extcon_driver = { + .probe = usb_extcon_probe, + .remove = usb_extcon_remove, + .driver = { + .name = "extcon-usb-gpio", + .pm = &usb_extcon_pm_ops, + .of_match_table = usb_extcon_dt_match, + }, +}; + +module_platform_driver(usb_extcon_driver); + +MODULE_AUTHOR("Roger Quadros "); +MODULE_DESCRIPTION("USB GPIO extcon driver"); +MODULE_LICENSE("GPL v2");