Messages in this thread | | | Date | Thu, 6 Mar 2014 14:00:24 +0530 | From | Kishon Vijay Abraham I <> | Subject | Re: [PATCH v9 3/4] phy: Add new Exynos USB 2.0 PHY driver |
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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@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).
The PHY power-on callback is anyway called with mutex held, so I guess it's fine to have clk_prepare_enable() here.
Thanks Kishon
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