Hello, > Subject: Re: [PATCH v9 3/4] phy: Add new Exynos USB 2.0 PHY driver > > > > On Thursday 06 March 2014 01:56 PM, Anton Tikhomirov wrote: > > 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@xxxxxxxxxxx> > >> + * > >> + * 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). > > The PHY power-on callback is anyway called with mutex held, so I guess > it's fine to have clk_prepare_enable() here. If we rely totally on generic PHY functions such as phy_power_on() and friends, why do we need to use locking in callbacks at all. > > Thanks > Kishon -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html