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    SubjectRE: [PATCH v9 3/4] phy: Add new Exynos USB 2.0 PHY driver
    Date
    Hi Kamil,

    ...

    > +| 3. Supporting SoCs
    > ++--------------------
    > +
    > +To support a new SoC a new file should be added to the drivers/phy
    > +directory. Each SoC's configuration is stored in an instance of the
    > +struct samsung_usb2_phy_config.
    > +
    > +struct samsung_usb2_phy_config {
    > + const struct samsung_usb2_common_phy *phys;
    > + unsigned int num_phys;
    > + bool has_mode_switch;

    You missed rate_to_clk here.

    > +};
    > +

    ...

    > diff --git a/drivers/phy/phy-samsung-usb2.c b/drivers/phy/phy-samsung-
    > usb2.c
    > new file mode 100644
    > index 0000000..c3b7719
    > --- /dev/null
    > +++ b/drivers/phy/phy-samsung-usb2.c
    > @@ -0,0 +1,222 @@
    > +/*
    > + * Samsung SoC USB 1.1/2.0 PHY driver
    > + *
    > + * Copyright (C) 2013 Samsung Electronics Co., Ltd.
    > + * Author: Kamil Debski <k.debski@samsung.com>
    > + *
    > + * This program is free software; you can redistribute it and/or
    > modify
    > + * it under the terms of the GNU General Public License version 2 as
    > + * published by the Free Software Foundation.
    > + */
    > +
    > +#include <linux/clk.h>
    > +#include <linux/mfd/syscon.h>
    > +#include <linux/module.h>
    > +#include <linux/of.h>
    > +#include <linux/of_address.h>
    > +#include <linux/phy/phy.h>
    > +#include <linux/platform_device.h>
    > +#include <linux/spinlock.h>
    > +#include "phy-samsung-usb2.h"
    > +
    > +static int samsung_usb2_phy_power_on(struct phy *phy)
    > +{
    > + struct samsung_usb2_phy_instance *inst = phy_get_drvdata(phy);
    > + struct samsung_usb2_phy_driver *drv = inst->drv;
    > + int ret;
    > +
    > + dev_dbg(drv->dev, "Request to power_on \"%s\" usb phy\n",
    > + inst->cfg->label);
    > + ret = clk_prepare_enable(drv->clk);

    clk_prepare_enable() can sleep, and therefore doesn't allow
    samusng_usb2_phy_power_on() to be used in atomic context
    (e.g. inside spin_lock-ed area), what sometimes may be desirable.
    What about to prepare clock in probe, and just enable it here
    (note: clk_enable() doesn't sleep).

    > + if (ret)
    > + goto err_main_clk;
    > + ret = clk_prepare_enable(drv->ref_clk);
    > + if (ret)
    > + goto err_instance_clk;
    > + if (inst->cfg->power_on) {
    > + spin_lock(&drv->lock);
    > + ret = inst->cfg->power_on(inst);
    > + spin_unlock(&drv->lock);
    > + }
    > +
    > + return 0;

    Thank you



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