Re: [RFC 01/19] extcon: add extcon-odroid-usbotg driver

[Roger Quadros <rogerq@ti.com>]

On 19/03/15 14:19, George Cherian wrote:
> Hi Robert,
> 
> +Roger
> On Thu, Mar 19, 2015 at 5:37 PM, Robert Baldyga <r.baldyga@samsung.com> wrote:
>> Hi George,
>>
>> On 03/19/2015 09:50 AM, George Cherian wrote:
>>> Hi Robert,
>>>
>>> This looks like a extcon driver based on gpio for USB.
>>>
>>> Roger posted a generic one a while back.
>>> https://lkml.org/lkml/2015/2/2/187
>>>
>>> Doesn't this serve the purpose rather than adding this driver?
>>
>> Roger's driver doesn't support VBUS state detection so it cannot handle
> I feel Roger's driver could be extended for supporting VBUS.
> Also I think Roger's driver is about to get merged.
> Probably, Roger or Chanwoo can better tell that

It is already queued for 4.1 and is available in linux-next.

> 
>> situation when USB cable is unpluged. In addition some of Odroid boards
>> has only VBUS detection (without ID pin), so this driver cannot handle
>> them at all.

why not?

x15-beagleboard also gets VBUS event over GPIO and I was planning to extent it
to support VBUS detection.

cheers,
-roger

>>
>> Best regards,
>> Robert
>>
>>>
>>> On Wed, Mar 18, 2015 at 7:34 PM, Robert Baldyga <r.baldyga@samsung.com> wrote:
>>>> This patch adds extcon driver for Odroid U3, U3+ and X boards.
>>>> It recognizes type of USB cable connected to Odroid board basing on
>>>> two signal lines VBUS_DET and OTG_ID (the second one is present only
>>>> on Odroid U3+ board).
>>>>
>>>> Following table of states presents relationship between this signals
>>>> and detected cable type:
>>>>
>>>> state    | VBUS_DET |  OTG_ID
>>>> -------------------------------
>>>> USB      |    H     |    H
>>>> USB_HOST |    H     |    L
>>>> disconn. |    L     |    H
>>>> USB-HOST |    L     |    L
>>>>
>>>> This driver is based on extcon-gpio driver.
>>>>
>>>> Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com>
>>>> Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
>>>> ---
>>>>  drivers/extcon/Kconfig                |   4 +
>>>>  drivers/extcon/Makefile               |   1 +
>>>>  drivers/extcon/extcon-odroid-usbotg.c | 256 ++++++++++++++++++++++++++++++++++
>>>>  3 files changed, 261 insertions(+)
>>>>  create mode 100644 drivers/extcon/extcon-odroid-usbotg.c
>>>>
>>>> diff --git a/drivers/extcon/Kconfig b/drivers/extcon/Kconfig
>>>> index 6a1f7de..891dca3 100644
>>>> --- a/drivers/extcon/Kconfig
>>>> +++ b/drivers/extcon/Kconfig
>>>> @@ -93,4 +93,8 @@ config EXTCON_SM5502
>>>>           Silicon Mitus SM5502. The SM5502 is a USB port accessory
>>>>           detector and switch.
>>>>
>>>> +config EXTCON_ODROID_USBOTG
>>>> +       tristate "Extcon Odroid U3, U3+, X and XU USB OTG port"
>>>> +       depends on OF_GPIO
>>>> +
>>>>  endif # MULTISTATE_SWITCH
>>>> diff --git a/drivers/extcon/Makefile b/drivers/extcon/Makefile
>>>> index 0370b42..514384e 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_ODROID_USBOTG) += extcon-odroid-usbotg.o
>>>> diff --git a/drivers/extcon/extcon-odroid-usbotg.c b/drivers/extcon/extcon-odroid-usbotg.c
>>>> new file mode 100644
>>>> index 0000000..7f71c48
>>>> --- /dev/null
>>>> +++ b/drivers/extcon/extcon-odroid-usbotg.c
>>>> @@ -0,0 +1,256 @@
>>>> +/*
>>>> + *  drivers/extcon/extcon-odroid-usbotg.c
>>>> + *
>>>> + *  USB cable extcon driver for Odroid U3, Odroid U3+ and Odroid X
>>>> + *
>>>> + * Copyright (C) 2014 Samsung Electronics
>>>> + * Author: Lukasz Stelmach <l.stelmach@samsung.com>
>>>> + * Author: Robert Baldyga <r.baldyga@samsung.com>
>>>> + *
>>>> + * based on drivers/extcon/extcon-gpio.c
>>>> + * Copyright (C) 2008 Google, Inc.
>>>> + * Author: Mike Lockwood <lockwood@android.com>
>>>> + *
>>>> + * This software is licensed under the terms of the GNU General Public
>>>> + * License version 2, as published by the Free Software Foundation, and
>>>> + * may be copied, distributed, and modified under those terms.
>>>> + *
>>>> + * 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 <linux/module.h>
>>>> +#include <linux/kernel.h>
>>>> +#include <linux/init.h>
>>>> +#include <linux/interrupt.h>
>>>> +#include <linux/platform_device.h>
>>>> +#include <linux/slab.h>
>>>> +#include <linux/gpio.h>
>>>> +#include <linux/of_gpio.h>
>>>> +#include <linux/extcon.h>
>>>> +#include <linux/extcon/extcon-gpio.h>
>>>> +#include <linux/delay.h>
>>>> +
>>>> +enum {
>>>> +       EXTCON_CABLE_USB = 0,
>>>> +       EXTCON_CABLE_USB_HOST,
>>>> +
>>>> +       _EXTCON_CABLE_NUM,
>>>> +};
>>>> +
>>>> +static const char * const odroid_usbotg_cable[] = {
>>>> +       [EXTCON_CABLE_USB] = "USB",
>>>> +       [EXTCON_CABLE_USB_HOST] = "USB-HOST",
>>>> +
>>>> +       NULL,
>>>> +};
>>>> +
>>>> +struct odroid_usbotg_data {
>>>> +       struct extcon_dev *edev;
>>>> +       struct gpio_desc *otg_id;
>>>> +       struct gpio_desc *vbus_det;
>>>> +       int otg_id_irq;
>>>> +       int vbus_det_irq;
>>>> +       unsigned long debounce_ms;
>>>> +};
>>>> +
>>>> +/*
>>>> + * state    | VBUS_DET |  OTG_ID
>>>> + * -------------------------------
>>>> + * USB      |    H     |    H
>>>> + * USB-HOST |    H     |    L
>>>> + * disconn. |    L     |    H
>>>> + * USB-HOST |    L     |    L
>>>> + *
>>>> + * Only Odroid U3+ has OTG_ID line. U3 and X versions can detect only
>>>> + * USB slave cable.
>>>> + */
>>>> +
>>>> +static void odroid_usbotg_detect_cable(struct odroid_usbotg_data *extcon_data)
>>>> +{
>>>> +       int state;
>>>> +
>>>> +       mdelay(extcon_data->debounce_ms);
>>>> +
>>>> +       if (extcon_data->otg_id)
>>>> +               state = (gpiod_get_value(extcon_data->vbus_det) << 1) |
>>>> +                       gpiod_get_value(extcon_data->otg_id);
>>>> +       else
>>>> +               state = (gpiod_get_value(extcon_data->vbus_det) << 1) | 1;
>>>> +
>>>> +       dev_dbg(&extcon_data->edev->dev, "cable state changed to %d\n", state);
>>>> +
>>>> +       if (state & 0x1)
>>>> +               extcon_set_cable_state_(extcon_data->edev,
>>>> +                       EXTCON_CABLE_USB_HOST, false);
>>>> +       if (state != 0x3)
>>>> +               extcon_set_cable_state_(extcon_data->edev,
>>>> +                       EXTCON_CABLE_USB, false);
>>>> +
>>>> +       if (!(state & 0x1))
>>>> +               extcon_set_cable_state_(extcon_data->edev,
>>>> +                       EXTCON_CABLE_USB_HOST, true);
>>>> +       else if (state == 0x3)
>>>> +               extcon_set_cable_state_(extcon_data->edev,
>>>> +                       EXTCON_CABLE_USB, true);
>>>> +}
>>>> +
>>>> +static irqreturn_t gpio_irq_handler(int irq, void *dev_id)
>>>> +{
>>>> +       struct odroid_usbotg_data *extcon_data = dev_id;
>>>> +
>>>> +       odroid_usbotg_detect_cable(extcon_data);
>>>> +
>>>> +       return IRQ_HANDLED;
>>>> +}
>>>> +
>>>> +static int odroid_usbotg_parse_dt(struct platform_device *pdev,
>>>> +                                   struct odroid_usbotg_data *extcon_data)
>>>> +{
>>>> +       struct device_node *np = pdev->dev.of_node;
>>>> +       u32 val;
>>>> +
>>>> +       if (!np)
>>>> +               return -ENODEV;
>>>> +
>>>> +       extcon_data->edev->name = np->name;
>>>> +
>>>> +       if (of_property_read_u32(np, "debounce", &val) != 0)
>>>> +               val = 50;
>>>> +       extcon_data->debounce_ms = val;
>>>> +
>>>> +       return 0;
>>>> +}
>>>> +
>>>> +static int odroid_usbotg_probe(struct platform_device *pdev)
>>>> +{
>>>> +       struct odroid_usbotg_data *extcon_data;
>>>> +       int ret = 0;
>>>> +
>>>> +       extcon_data = devm_kzalloc(&pdev->dev,
>>>> +               sizeof(struct odroid_usbotg_data), GFP_KERNEL);
>>>> +       if (!extcon_data)
>>>> +               return -ENOMEM;
>>>> +
>>>> +       extcon_data->edev = devm_kzalloc(&pdev->dev, sizeof(struct extcon_dev),
>>>> +                                        GFP_KERNEL);
>>>> +       if (IS_ERR(extcon_data->edev)) {
>>>> +               dev_err(&pdev->dev, "failed to allocate extcon device\n");
>>>> +               return -ENOMEM;
>>>> +       }
>>>> +       extcon_data->edev->supported_cable = odroid_usbotg_cable;
>>>> +
>>>> +       ret = odroid_usbotg_parse_dt(pdev, extcon_data);
>>>> +       if (IS_ERR_VALUE(ret)) {
>>>> +               dev_err(&pdev->dev, "failed to get data from device tree\n");
>>>> +               return ret;
>>>> +       }
>>>> +
>>>> +       /* gpios */
>>>> +       extcon_data->vbus_det = devm_gpiod_get(&pdev->dev, "vbus-det");
>>>> +       if (IS_ERR(extcon_data->vbus_det)) {
>>>> +               dev_err(&pdev->dev, "failed to get vbus_det gpio\n");
>>>> +               return PTR_ERR(extcon_data->vbus_det);
>>>> +       }
>>>> +       extcon_data->otg_id = devm_gpiod_get_optional(&pdev->dev, "otg-id");
>>>> +
>>>> +       extcon_data->edev->dev.parent = &pdev->dev;
>>>> +       ret = extcon_dev_register(extcon_data->edev);
>>>> +       if (ret < 0)
>>>> +               return ret;
>>>> +
>>>> +       /* irq */
>>>> +       extcon_data->vbus_det_irq = gpiod_to_irq(extcon_data->vbus_det);
>>>> +       if (extcon_data->vbus_det_irq < 0) {
>>>> +               dev_err(&pdev->dev, "failed to get irq from vbus_det\n");
>>>> +               ret = extcon_data->vbus_det_irq;
>>>> +               goto err;
>>>> +       }
>>>> +       ret = request_threaded_irq(extcon_data->vbus_det_irq, NULL,
>>>> +                                  gpio_irq_handler, IRQF_ONESHOT |
>>>> +                                  IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
>>>> +                                  pdev->name, extcon_data);
>>>> +       if (ret < 0) {
>>>> +               dev_err(&pdev->dev, "failed to request vbus_det irq\n");
>>>> +               goto err;
>>>> +       }
>>>> +
>>>> +       if (extcon_data->otg_id) {
>>>> +               extcon_data->otg_id_irq = gpiod_to_irq(extcon_data->otg_id);
>>>> +               if (extcon_data->otg_id_irq < 0) {
>>>> +                       dev_err(&pdev->dev, "failed to get irq from otg_id\n");
>>>> +                       ret = extcon_data->otg_id_irq;
>>>> +                       goto err;
>>>> +               }
>>>> +               ret = request_threaded_irq(extcon_data->otg_id_irq, NULL,
>>>> +                               gpio_irq_handler, IRQF_ONESHOT |
>>>> +                               IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
>>>> +                               pdev->name, extcon_data);
>>>> +               if (ret < 0) {
>>>> +                       dev_err(&pdev->dev, "failed to request otg_id irq\n");
>>>> +                       goto err;
>>>> +               }
>>>> +       }
>>>> +
>>>> +       platform_set_drvdata(pdev, extcon_data);
>>>> +       /* Perform initial detection */
>>>> +       odroid_usbotg_detect_cable(extcon_data);
>>>> +
>>>> +       dev_dbg(&pdev->dev, "probe: success\n");
>>>> +
>>>> +       return 0;
>>>> +
>>>> +err:
>>>> +       extcon_dev_unregister(extcon_data->edev);
>>>> +
>>>> +       return ret;
>>>> +}
>>>> +
>>>> +static int odroid_usbotg_remove(struct platform_device *pdev)
>>>> +{
>>>> +       struct odroid_usbotg_data *extcon_data = platform_get_drvdata(pdev);
>>>> +
>>>> +       free_irq(extcon_data->vbus_det_irq, extcon_data);
>>>> +       if (extcon_data->otg_id)
>>>> +               free_irq(extcon_data->otg_id_irq, extcon_data);
>>>> +       extcon_dev_unregister(extcon_data->edev);
>>>> +
>>>> +       return 0;
>>>> +}
>>>> +
>>>> +static const struct of_device_id odroid_usbotg_of_match[] = {
>>>> +       { .compatible = "extcon-odroid-usbotg" },
>>>> +       { },
>>>> +};
>>>> +MODULE_DEVICE_TABLE(of, odroid_usbotg_of_match);
>>>> +
>>>> +static struct platform_driver odroid_usbotg_driver = {
>>>> +       .probe          = odroid_usbotg_probe,
>>>> +       .remove         = odroid_usbotg_remove,
>>>> +       .driver         = {
>>>> +               .name   = "odroid-usbotg",
>>>> +               .owner  = THIS_MODULE,
>>>> +               .of_match_table = of_match_ptr(odroid_usbotg_of_match)
>>>> +       },
>>>> +};
>>>> +
>>>> +static int __init odroid_usbotg_init(void)
>>>> +{
>>>> +       return platform_driver_register(&odroid_usbotg_driver);
>>>> +}
>>>> +
>>>> +subsys_initcall(odroid_usbotg_init);
>>>> +
>>>> +static void __exit odroid_usbotg_cleanup(void)
>>>> +{
>>>> +       platform_driver_unregister(&odroid_usbotg_driver);
>>>> +}
>>>> +
>>>> +module_exit(odroid_usbotg_cleanup);
>>>> +
>>>> +MODULE_AUTHOR("Lukasz Stelmach <l.stelmach@samsung.com>, Robert Baldyga <r.baldyga@samsung.com>");
>>>> +MODULE_DESCRIPTION("USB OTG extcon driver for Odroid U3, U3+ and X");
>>>> +MODULE_LICENSE("GPL");
>>>> --
>>>> 1.9.1
>>>>
>>>> --
>>>> To unsubscribe from this list: send the line "unsubscribe linux-usb" in
>>>> the body of a message to majordomo@vger.kernel.org
>>>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>> --
>>> To unsubscribe from this list: send the line "unsubscribe linux-usb" in
>>> the body of a message to majordomo@vger.kernel.org
>>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>>
>>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-usb" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>