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Message-ID: <CAHp75Vc+=UHk1UbCL6xsSJCuNtjLv-J5a=z=OwE1psCruZUo3g@mail.gmail.com>
Date: Fri, 6 Nov 2015 22:47:30 +0200
From: Andy Shevchenko <andy.shevchenko@...il.com>
To: John Crispin <blogic@...nwrt.org>
Cc: Kishon Vijay Abraham I <kishon@...com>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] phy: ralink-usb: add driver for Mediatek/Ralink
On Wed, Nov 4, 2015 at 12:54 PM, John Crispin <blogic@...nwrt.org> 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@...nwrt.org>
> + *
> + * 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_… != 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))
…;
if (!IS_ERR(rstdev))
…;
?
> +
> + 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@...nwrt.org>");
> +MODULE_LICENSE("GPL v2");
> --
> 1.7.10.4
> --
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--
With Best Regards,
Andy Shevchenko
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