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

[George Cherian]

Hi Robert,

+Roger
On Thu, Mar 19, 2015 at 5:37 PM, Robert Baldyga <r.baldyga@xxxxxxxxxxx> 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

> 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.
>
> Best regards,
> Robert
>
>>
>> On Wed, Mar 18, 2015 at 7:34 PM, Robert Baldyga <r.baldyga@xxxxxxxxxxx> 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: Åukasz Stelmach <l.stelmach@xxxxxxxxxxx>
>>> Signed-off-by: Robert Baldyga <r.baldyga@xxxxxxxxxxx>
>>> ---
>>>  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@xxxxxxxxxxx>
>>> + * Author: Robert Baldyga <r.baldyga@xxxxxxxxxxx>
>>> + *
>>> + * based on drivers/extcon/extcon-gpio.c
>>> + * Copyright (C) 2008 Google, Inc.
>>> + * Author: Mike Lockwood <lockwood@xxxxxxxxxxx>
>>> + *
>>> + * 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@xxxxxxxxxxx>, Robert Baldyga <r.baldyga@xxxxxxxxxxx>");
>>> +MODULE_DESCRIPTION("USB OTG extcon driver for Odroid U3, U3+ and X");
>>> +MODULE_LICENSE("GPL");
>>> --
>>> 1.9.1
>>>
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