Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753980Ab3EGFVc (ORCPT ); Tue, 7 May 2013 01:21:32 -0400 Received: from comal.ext.ti.com ([198.47.26.152]:50731 "EHLO comal.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750772Ab3EGFVa (ORCPT ); Tue, 7 May 2013 01:21:30 -0400 Message-ID: <51888F45.4030303@ti.com> Date: Tue, 7 May 2013 10:51:09 +0530 From: Kishon Vijay Abraham I User-Agent: Mozilla/5.0 (X11; Linux i686; rv:17.0) Gecko/20130329 Thunderbird/17.0.5 MIME-Version: 1.0 To: "myungjoo.ham" , Graeme Gregory CC: , , , , , , , , , , , , , Subject: Re: [PATCH v4] extcon: Palmas Extcon Driver References: <1362662506-14823-4-git-send-email-kishon@ti.com> <1367846225-15685-1-git-send-email-kishon@ti.com> <005c01ce4abb$d956fea0$8c04fbe0$@samsung.com> In-Reply-To: <005c01ce4abb$d956fea0$8c04fbe0$@samsung.com> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7085 Lines: 240 Hi, On Tuesday 07 May 2013 06:13 AM, myungjoo.ham wrote: >> From: Graeme Gregory >> >> This is the driver for the USB comparator built into the palmas chip. It >> handles the various USB OTG events that can be generated by cable >> insertion/removal. >> >> Signed-off-by: Graeme Gregory >> Signed-off-by: Moiz Sonasath >> Signed-off-by: Ruchika Kharwar >> Signed-off-by: Kishon Vijay Abraham I >> [kishon@ti.com: adapted palmas usb driver to use the extcon framework] >> Signed-off-by: Sebastien Guiriec > > Here goes some comments in the code: > > [] > >> diff --git a/drivers/extcon/extcon-palmas.c > b/drivers/extcon/extcon-palmas.c >> new file mode 100644 >> index 0000000..3ef042f >> --- /dev/null >> +++ b/drivers/extcon/extcon-palmas.c >> @@ -0,0 +1,389 @@ >> +/* >> + * Palmas USB transceiver driver >> + * >> + * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com >> + * This program is free software; you can redistribute it and/or modify >> + * it under the terms of the GNU General Public License as published by >> + * the Free Software Foundation; either version 2 of the License, or >> + * (at your option) any later version. >> + * >> + * Author: Graeme Gregory >> + * Author: Kishon Vijay Abraham I >> + * >> + * Based on twl6030_usb.c >> + * >> + * Author: Hema HK >> + * >> + * 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. >> + */ > > Why the email addresses are masked in the source code? > (I'm just curious as this is the first time to see such in kernel source) That was not intentional. Took the previous version from the net. My bad. > >> + >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> + >> +static const char *palmas_extcon_cable[] = { >> + [0] = "USB", >> + [1] = "USB-HOST", > > [1] = "USB-Host", > >> + NULL, >> +}; >> + >> +static const int mutually_exclusive[] = {0x3, 0x0}; >> + >> +static void palmas_usb_wakeup(struct palmas *palmas, int enable) >> +{ >> + if (enable) >> + palmas_write(palmas, PALMAS_USB_OTG_BASE, PALMAS_USB_WAKEUP, >> + PALMAS_USB_WAKEUP_ID_WK_UP_COMP); >> + else >> + palmas_write(palmas, PALMAS_USB_OTG_BASE, PALMAS_USB_WAKEUP, > 0); >> +} >> + >> +static ssize_t palmas_usb_vbus_show(struct device *dev, >> + struct device_attribute *attr, char *buf) >> +{ >> + unsigned long flags; >> + int ret = -EINVAL; >> + struct palmas_usb *palmas_usb = dev_get_drvdata(dev); >> + >> + spin_lock_irqsave(&palmas_usb->lock, flags); > > This spinlock is used in this sysfs-show function only. > Is this really needed? > The only protected value here is "linkstat", which is "readonly" > in this protected context. > Thus, removing the spin_lock and updating like the following should > be the same with less overhead: > > int linkstat = palmas_usb->linkstat; > switch(linkstat) { hmm.. ok. > > >> + >> + switch (palmas_usb->linkstat) { >> + case PALMAS_USB_STATE_VBUS: >> + ret = snprintf(buf, PAGE_SIZE, "vbus\n"); >> + break; >> + case PALMAS_USB_STATE_ID: >> + ret = snprintf(buf, PAGE_SIZE, "id\n"); >> + break; >> + case PALMAS_USB_STATE_DISCONNECT: >> + ret = snprintf(buf, PAGE_SIZE, "none\n"); >> + break; >> + default: >> + ret = snprintf(buf, PAGE_SIZE, "UNKNOWN\n"); >> + } >> + spin_unlock_irqrestore(&palmas_usb->lock, flags); >> + >> + return ret; >> +} >> +static DEVICE_ATTR(vbus, 0444, palmas_usb_vbus_show, NULL); >> + > > [] > >> + >> +static void palmas_set_vbus_work(struct work_struct *data) >> +{ >> + int ret; >> + struct palmas_usb *palmas_usb = container_of(data, struct > palmas_usb, >> + > set_vbus_work); >> + >> + if (IS_ERR_OR_NULL(palmas_usb->vbus_reg)) { >> + dev_err(palmas_usb->dev, "invalid regulator\n"); >> + return; >> + } >> + >> + /* >> + * Start driving VBUS. Set OPA_MODE bit in CHARGERUSB_CTRL1 >> + * register. This enables boost mode. >> + */ >> + >> + if (palmas_usb->vbus_enable) { >> + ret = regulator_enable(palmas_usb->vbus_reg); >> + if (ret) >> + dev_dbg(palmas_usb->dev, "regulator enable > failed\n"); >> + } else { >> + regulator_disable(palmas_usb->vbus_reg); >> + } >> +} >> + >> +static int palmas_set_vbus(struct phy_companion *comparator, bool > enabled) >> +{ >> + struct palmas_usb *palmas_usb = comparator_to_palmas(comparator); >> + >> + palmas_usb->vbus_enable = enabled; >> + schedule_work(&palmas_usb->set_vbus_work); >> + >> + return 0; >> +} >> + >> +static int palmas_start_srp(struct phy_companion *comparator) >> +{ >> + struct palmas_usb *palmas_usb = comparator_to_palmas(comparator); >> + >> + palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE, >> + PALMAS_USB_VBUS_CTRL_SET, > PALMAS_USB_VBUS_CTRL_SET_VBUS_DISCHRG >> + | PALMAS_USB_VBUS_CTRL_SET_VBUS_IADP_SINK); >> + palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE, >> + PALMAS_USB_VBUS_CTRL_SET, >> + PALMAS_USB_VBUS_CTRL_SET_VBUS_CHRG_VSYS | >> + PALMAS_USB_VBUS_CTRL_SET_VBUS_IADP_SINK); >> + >> + mdelay(100); > > Why not msleep()? It's long enough to consider sleep. > Is this in an atomic context? (if so, 100msec seems even more awful) I guess it shouldn't be called from atomic context. Actually srp hasn't been tested because the controller driver we use with palmas dont have the infrastructure yet. > >> + >> + palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE, >> + PALMAS_USB_VBUS_CTRL_CLR, >> + PALMAS_USB_VBUS_CTRL_SET_VBUS_CHRG_VSYS | >> + PALMAS_USB_VBUS_CTRL_SET_VBUS_CHRG_VSYS); >> + >> + return 0; >> +} >> + >> +static void palmas_dt_to_pdata(struct device_node *node, >> + struct palmas_usb_platform_data *pdata) >> +{ >> + pdata->no_control_vbus = of_property_read_bool(node, >> + "ti,no_control_vbus"); >> + pdata->wakeup = of_property_read_bool(node, "ti,wakeup"); >> +} >> + >> +static int palmas_usb_probe(struct platform_device *pdev) >> +{ > > [] > >> + /* init spinlock for workqueue */ >> + spin_lock_init(&palmas_usb->lock); > > [] > >> + /* init spinlock for workqueue */ >> + spin_lock_init(&palmas_usb->lock); > > Why this lock is initialized again? Will remove it. Thanks Kishon -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/