Re: [PATCH] phy: ralink-usb: add driver for Mediatek/Ralink

[Andy Shevchenko]

On Wed, Nov 4, 2015 at 12:54 PM, John Crispin <blogic@xxxxxxxxxxx> wrote:
> Add a driver to setup the USB phy on Mediatek/Ralink SoCs.
> The driver is trivial and only sets the power and host/device mode.

> +/*
> + * Ralink USB phy driver
> + *
> + * Copyright (C) 2014 John Crispin <blogic@xxxxxxxxxxx>
> + *
> + * Based on code from
> + * Allwinner Technology Co., Ltd. <www.allwinnertech.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.
> + *
> + * 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/delay.h>
> +#include <linux/err.h>
> +#include <linux/io.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/phy/phy.h>
> +#include <linux/platform_device.h>
> +#include <linux/reset.h>
> +#include <linux/of_platform.h>
> +
> +#include <asm/mach-ralink/ralink_regs.h>
> +
> +#define RT_SYSC_REG_SYSCFG1            0x014
> +#define RT_SYSC_REG_CLKCFG1            0x030
> +#define RT_SYSC_REG_USB_PHY_CFG                0x05c
> +
> +#define RT_RSTCTRL_UDEV                        BIT(25)
> +#define RT_RSTCTRL_UHST                        BIT(22)
> +#define RT_SYSCFG1_USB0_HOST_MODE      BIT(10)
> +
> +#define MT7620_CLKCFG1_UPHY0_CLK_EN    BIT(25)
> +#define MT7620_CLKCFG1_UPHY1_CLK_EN    BIT(22)
> +#define RT_CLKCFG1_UPHY1_CLK_EN                BIT(20)
> +#define RT_CLKCFG1_UPHY0_CLK_EN                BIT(18)
> +
> +#define USB_PHY_UTMI_8B60M             BIT(1)
> +#define UDEV_WAKEUP                    BIT(0)
> +
> +static atomic_t usb_pwr_ref = ATOMIC_INIT(0);
> +static struct reset_control *rstdev;
> +static struct reset_control *rsthost;
> +static u32 phy_clk;
> +static struct phy *rt_phy;
> +
> +static void usb_phy_enable(int state)
> +{
> +       if (state)
> +               rt_sysc_m32(0, phy_clk, RT_SYSC_REG_CLKCFG1);
> +       else
> +               rt_sysc_m32(phy_clk, 0, RT_SYSC_REG_CLKCFG1);
> +       mdelay(100);

Where 100 comes from? Perhaps comment line?

> +}
> +
> +static int ralink_usb_phy_init(struct phy *_phy)
> +{
> +       return 0;
> +}
> +
> +static int ralink_usb_phy_exit(struct phy *_phy)
> +{
> +       return 0;
> +}
> +
> +static int ralink_usb_phy_power_on(struct phy *_phy)

_phy -> phy ?

> +{
> +       if (atomic_inc_return(&usb_pwr_ref) == 1) {

if (!atomic_â != 1)
 return 0;

?

> +               int host = 1;
> +               u32 t;
> +
> +               usb_phy_enable(1);
> +
> +               if (host) {
> +                       rt_sysc_m32(0, RT_SYSCFG1_USB0_HOST_MODE,
> +                                      RT_SYSC_REG_SYSCFG1);
> +                       if (!IS_ERR(rsthost))
> +                               reset_control_deassert(rsthost);
> +                       if (!IS_ERR(rstdev))
> +                               reset_control_deassert(rstdev);
> +               } else {
> +                       rt_sysc_m32(RT_SYSCFG1_USB0_HOST_MODE, 0,
> +                                   RT_SYSC_REG_SYSCFG1);
> +                       if (!IS_ERR(rstdev))
> +                               reset_control_deassert(rstdev);
> +               }
> +               mdelay(100);

Same question about 100 as above.

Aha, what about

usb_phy_enable(host);
if (host && !IS_ERR(rsthost))
 â;
if (!IS_ERR(rstdev))
 â;

?


> +
> +               t = rt_sysc_r32(RT_SYSC_REG_USB_PHY_CFG);
> +               dev_info(&_phy->dev, "remote usb device wakeup %s\n",
> +                       (t & UDEV_WAKEUP) ? ("enabbled") : ("disabled"));
> +               if (t & USB_PHY_UTMI_8B60M)
> +                       dev_info(&_phy->dev, "UTMI 8bit 60MHz\n");
> +               else
> +                       dev_info(&_phy->dev, "UTMI 16bit 30MHz\n");
> +       }
> +
> +       return 0;
> +}
> +
> +static int ralink_usb_phy_power_off(struct phy *_phy)
> +{
> +       if (atomic_dec_return(&usb_pwr_ref) == 0) {
> +               usb_phy_enable(0);

Okay, it seems you have to use atomic variable result as parameter to
off() / on(). Can you refactor them to have a common code together?

> +               if (!IS_ERR(rstdev))
> +                       reset_control_assert(rstdev);
> +               if (!IS_ERR(rsthost))
> +                       reset_control_assert(rsthost);
> +       }
> +
> +       return 0;
> +}
> +
> +static struct phy_ops ralink_usb_phy_ops = {
> +       .init           = ralink_usb_phy_init,
> +       .exit           = ralink_usb_phy_exit,
> +       .power_on       = ralink_usb_phy_power_on,
> +       .power_off      = ralink_usb_phy_power_off,
> +       .owner          = THIS_MODULE,
> +};
> +
> +static struct phy *ralink_usb_phy_xlate(struct device *dev,
> +                                       struct of_phandle_args *args)
> +{
> +       return rt_phy;
> +}
> +
> +static const struct of_device_id ralink_usb_phy_of_match[] = {
> +       {
> +               .compatible = "ralink,rt3xxx-usbphy",
> +               .data = (void *) (RT_CLKCFG1_UPHY1_CLK_EN |
> +                                 RT_CLKCFG1_UPHY0_CLK_EN)
> +       }, {
> +               .compatible = "ralink,mt7620a-usbphy",
> +               .data = (void *) (MT7620_CLKCFG1_UPHY1_CLK_EN |
> +                                 MT7620_CLKCFG1_UPHY0_CLK_EN) },
> +       { },
> +};
> +MODULE_DEVICE_TABLE(of, ralink_usb_phy_of_match);
> +
> +static int ralink_usb_phy_probe(struct platform_device *pdev)
> +{
> +       struct device *dev = &pdev->dev;
> +       struct phy_provider *phy_provider;
> +       const struct of_device_id *match;
> +
> +       match = of_match_device(ralink_usb_phy_of_match, &pdev->dev);

if (!match)
 return -ENODEV;

> +       phy_clk = (int) match->data;
> +
> +       rsthost = devm_reset_control_get(&pdev->dev, "host");
> +       rstdev = devm_reset_control_get(&pdev->dev, "device");
> +
> +       rt_phy = devm_phy_create(dev, NULL, &ralink_usb_phy_ops, NULL);
> +       if (IS_ERR(rt_phy)) {
> +               dev_err(dev, "failed to create PHY\n");
> +               return PTR_ERR(rt_phy);
> +       }
> +
> +       phy_provider = devm_of_phy_provider_register(dev, ralink_usb_phy_xlate);
> +
> +       return PTR_ERR_OR_ZERO(phy_provider);
> +}
> +
> +static struct platform_driver ralink_usb_phy_driver = {
> +       .probe  = ralink_usb_phy_probe,
> +       .driver = {
> +               .of_match_table = ralink_usb_phy_of_match,
> +               .name  = "ralink-usb-phy",
> +       }
> +};
> +module_platform_driver(ralink_usb_phy_driver);
> +
> +MODULE_DESCRIPTION("Ralink USB phy driver");
> +MODULE_AUTHOR("John Crispin <blogic@xxxxxxxxxxx>");
> +MODULE_LICENSE("GPL v2");
> --
> 1.7.10.4
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/



-- 
With Best Regards,
Andy Shevchenko
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/