Hello. On 08/20/2014 06:42 PM, Kishon Vijay Abraham I wrote:
Sorry for the delayed reply, I was busy in other kernel areas. Should have replied yesterday though...
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Index: linux-phy/drivers/phy/phy-rcar-gen2.c =================================================================== --- /dev/null +++ linux-phy/drivers/phy/phy-rcar-gen2.c @@ -0,0 +1,341 @@ +/* + * Renesas R-Car Gen2 PHY driver + * + * Copyright (C) 2014 Renesas Solutions Corp. + * Copyright (C) 2014 Cogent Embedded, Inc. + * + * 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/delay.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/phy/phy.h> +#include <linux/platform_device.h> +#include <linux/spinlock.h> + +#include <asm/cmpxchg.h> + +#define USBHS_LPSTS 0x02 +#define USBHS_UGCTRL 0x80 +#define USBHS_UGCTRL2 0x84 +#define USBHS_UGSTS 0x88 /* The manuals have 0x90 */ + +/* Low Power Status register (LPSTS) */ +#define USBHS_LPSTS_SUSPM 0x4000 + +/* USB General control register (UGCTRL) */ +#define USBHS_UGCTRL_CONNECT 0x00000004 +#define USBHS_UGCTRL_PLLRESET 0x00000001 + +/* USB General control register 2 (UGCTRL2) */ +#define USBHS_UGCTRL2_USB2SEL 0x80000000 +#define USBHS_UGCTRL2_USB2SEL_PCI 0x00000000 +#define USBHS_UGCTRL2_USB2SEL_USB30 0x80000000 +#define USBHS_UGCTRL2_USB0SEL 0x00000030 +#define USBHS_UGCTRL2_USB0SEL_PCI 0x00000010 +#define USBHS_UGCTRL2_USB0SEL_HS_USB 0x00000030 + +/* USB General status register (UGSTS) */ +#define USBHS_UGSTS_LOCK 0x00000300 /* The manuals have 0x3 */ + +#define PHYS_PER_CHANNEL 2 + +struct rcar_gen2_phy { + struct phy *phy; + struct rcar_gen2_channel *channel; + int number; + u32 select_value; +}; + +struct rcar_gen2_channel { + struct device_node *of_node; + struct rcar_gen2_phy_driver *drv; + struct rcar_gen2_phy phys[PHYS_PER_CHANNEL]; + int selected_phy; + u32 select_mask; +}; + +struct rcar_gen2_phy_driver { + void __iomem *base; + struct clk *clk; + spinlock_t lock; + int num_channels; + struct rcar_gen2_channel *channels; +}; + +static int rcar_gen2_phy_init(struct phy *p) +{ + struct rcar_gen2_phy *phy = phy_get_drvdata(p); + struct rcar_gen2_channel *channel = phy->channel; + struct rcar_gen2_phy_driver *drv = channel->drv; + unsigned long flags; + u32 ugctrl2; + + /* + * Try to acquire exclusive access to PHY. The first driver calling + * phy_init() on a given channel wins, and all attempts to use another + * PHY on this channel will fail until phy_exit() is called by the first + * driver. Achieving this with cmpxcgh() should be SMP-safe. + */ + if (cmpxchg(&channel->selected_phy, -1, phy->number) != -1) + return -EBUSY;
This should be done in phy_get no?
No, if you mean the of_xlate() method: I need a place to release the lock which I wouldn't have in this case. If you mean modifying _of_phy_get(), it has no notion of channels and probably shouldn't have since the channels are a special case for this driver (and maybe some others) ...
Can we add this in phy-core? There might be other users who want to have exclusive access within the same phy provider.
The exclusive access is not within the provider in my case, it's within a channel (each of which has a corresponding DT subnode), so I don't think it's well representable in the phy-core. I'm not using your suggested subnode-per-PHY representation since it doesn't really fit my case well...
Rest of it looks fine to me.
Thanks.
Thanks Kishon
WBR, Sergei -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
