Messages in this thread | | | Date | Tue, 7 May 2013 10:51:09 +0530 | From | Kishon Vijay Abraham I <> | Subject | Re: [PATCH v4] extcon: Palmas Extcon Driver |
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Hi,
On Tuesday 07 May 2013 06:13 AM, myungjoo.ham wrote: >> From: Graeme Gregory <gg@slimlogic.co.uk> >> >> 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 <gg@slimlogic.co.uk> >> Signed-off-by: Moiz Sonasath <m-sonasath@ti.com> >> Signed-off-by: Ruchika Kharwar <ruchika@ti.com> >> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> >> [kishon@ti.com: adapted palmas usb driver to use the extcon framework] >> Signed-off-by: Sebastien Guiriec <s-guiriec@ti.com> > > 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 <gg@...mlogic.co.uk> >> + * Author: Kishon Vijay Abraham I <kishon@...com> >> + * >> + * Based on twl6030_usb.c >> + * >> + * Author: Hema HK <hemahk@...com> >> + * >> + * 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 <linux/module.h> >> +#include <linux/init.h> >> +#include <linux/interrupt.h> >> +#include <linux/platform_device.h> >> +#include <linux/io.h> >> +#include <linux/usb/phy_companion.h> >> +#include <linux/regulator/consumer.h> >> +#include <linux/err.h> >> +#include <linux/notifier.h> >> +#include <linux/slab.h> >> +#include <linux/delay.h> >> +#include <linux/mfd/palmas.h> >> +#include <linux/of.h> >> +#include <linux/of_platform.h> >> +#include <linux/extcon/extcon_palmas.h> >> + >> +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
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