Re: [PATCH] net: add init-regs for of_phy support

[Mark Rutland <mark.rutland@arm.com>]

On Mon, Feb 17, 2014 at 01:08:04PM +0000, Ben Dooks wrote:
> Add new init-regs field for of_phy nodes and make sure these
> get applied when the phy is configured.
> 
> This allows any phy node in an fdt to initialise registers
> that may not be set as standard by the driver at initialisation
> time, such as LED controls.

Why not have a driver for the particular PHY? If it's not standard we
don't need to pretend it is. If it has some extensions then the standard
compatible string can be a fallback entry in the compatible list.

I think allocating a compatible string and handling it in the kernel is
better than having arbitrary register poke values in the dt.

Thanks,
Mark.

> 
> Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
> ---
>  Documentation/devicetree/bindings/net/phy.txt | 12 ++++++
>  drivers/net/phy/phy_device.c                  | 59 ++++++++++++++++++++++++++-
>  2 files changed, 70 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/devicetree/bindings/net/phy.txt b/Documentation/devicetree/bindings/net/phy.txt
> index 58307d0..48d8ded 100644
> --- a/Documentation/devicetree/bindings/net/phy.txt
> +++ b/Documentation/devicetree/bindings/net/phy.txt
> @@ -20,6 +20,8 @@ Optional Properties:
>    assume clause 22. The compatible list may also contain other
>    elements.
>  - max-speed: Maximum PHY supported speed (10, 100, 1000...)
> +- init-regs: Set of registers to modify at initialisation as a
> +    a set of <register set clear>
>  
>  Example:
>  
> @@ -29,3 +31,13 @@ ethernet-phy@0 {
>  	interrupts = <35 1>;
>  	reg = <0>;
>  };
> +
> +ethernet-phy@0 {
> +	compatible = "ethernet-phy-ieee802.3-c22";
> +	interrupt-parent = <40000>;
> +	interrupts = <35 1>;
> +	reg = <0>;
> +
> +	/* set KSZ8041 LED mode bits correctly */
> +	init-reg = <0x1e 0x4000 0xc000>;
> +};
> diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
> index 82514e7..6741cdb 100644
> --- a/drivers/net/phy/phy_device.c
> +++ b/drivers/net/phy/phy_device.c
> @@ -33,6 +33,7 @@
>  #include <linux/mdio.h>
>  #include <linux/io.h>
>  #include <linux/uaccess.h>
> +#include <linux/of.h>
>  
>  #include <asm/irq.h>
>  
> @@ -532,6 +533,57 @@ static int phy_poll_reset(struct phy_device *phydev)
>  	return 0;
>  }
>  
> +#ifdef CONFIG_OF
> +static int of_phy_configure(struct phy_device *phydev)
> +{
> +	struct device *dev = &phydev->dev;
> +	struct device_node *of_node = dev->of_node;
> +	struct property *prop;
> +	const __be32 *ptr;
> +	u32 reg, set, clear;
> +	int len;
> +	int val;
> +
> +	if (!of_node)
> +		of_node = dev->parent->of_node;
> +	if (!of_node)
> +		return 0;
> +
> +	prop = of_find_property(of_node, "init-regs", &len);
> +	if (prop) {
> +		if (len % (sizeof(__be32) * 3)) {
> +			dev_err(dev, "init-regs not multiple of 3 entries\n");
> +			return -EINVAL;
> +		}
> +
> +		ptr = of_prop_next_u32(prop, ptr, &reg);
> +		while (ptr != NULL) {
> +			ptr = of_prop_next_u32(prop, ptr, &reg);
> +			ptr = of_prop_next_u32(prop, ptr, &set);
> +			ptr = of_prop_next_u32(prop, ptr, &clear);
> +
> +			val = phy_read(phydev, reg);
> +			if (val < 0) {
> +				dev_err(dev, "failed to read %d\n", reg);
> +				return val;
> +			}
> +
> +			val &= ~clear;
> +			val |= set;
> +			phy_write(phydev, reg, val);
> +
> +			dev_info(dev, "set d to %04x\n", reg, val);
> +
> +			ptr = of_prop_next_u32(prop, ptr, &reg);
> +		}
> +	}
> +
> +	return 0;
> +}
> +#else
> +static inline int of_phy_configure(struct phy_device *phydev) { return 0; }
> +#endif
> +
>  int phy_init_hw(struct phy_device *phydev)
>  {
>  	int ret;
> @@ -551,7 +603,12 @@ int phy_init_hw(struct phy_device *phydev)
>  	if (ret < 0)
>  		return ret;
>  
> -	return phydev->drv->config_init(phydev);
> +	ret = phydev->drv->config_init(phydev);
> +
> +	if (ret == 0)
> +		ret = of_phy_configure(phydev);
> +
> +	return ret;
>  }
>  EXPORT_SYMBOL(phy_init_hw);
>  
> -- 
> 1.8.5.3
> 
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