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SubjectRe: [PATCH] net/phy: micrel: Add clock support for KSZ8021/KSZ8031
On 10/09/2014 05:32 AM, Sascha Hauer wrote:
> The KSZ8021 and KSZ8031 support RMII reference input clocks of 25MHz
> and 50MHz. Both PHYs differ in the default frequency they expect
> after reset. If this differs from the actual input clock, then
> register 0x1f bit 7 must be changed.

Looks reasonable to me, some minor comments below:

>
> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
> ---
> Documentation/devicetree/bindings/net/micrel.txt | 6 ++++++
> drivers/net/phy/micrel.c | 19 +++++++++++++++++--
> include/linux/micrel_phy.h | 1 +
> 3 files changed, 24 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/net/micrel.txt b/Documentation/devicetree/bindings/net/micrel.txt
> index 98a3e61..e1d99b9 100644
> --- a/Documentation/devicetree/bindings/net/micrel.txt
> +++ b/Documentation/devicetree/bindings/net/micrel.txt
> @@ -16,3 +16,9 @@ Optional properties:
> KSZ8051: register 0x1f, bits 5..4
>
> See the respective PHY datasheet for the mode values.
> +
> + - clocks, clock-names: contains clocks according to the common clock bindings.
> +
> + supported clocks:
> + - KSZ8021, KSZ8031: "rmii-ref": The RMII refence input clock. Used
> + to determine the XI input clock.
> diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
> index 011dbda..ca130e9 100644
> --- a/drivers/net/phy/micrel.c
> +++ b/drivers/net/phy/micrel.c
> @@ -26,6 +26,7 @@
> #include <linux/phy.h>
> #include <linux/micrel_phy.h>
> #include <linux/of.h>
> +#include <linux/clk.h>
>
> /* Operation Mode Strap Override */
> #define MII_KSZPHY_OMSO 0x16
> @@ -72,9 +73,12 @@ static int ksz_config_flags(struct phy_device *phydev)
> {
> int regval;
>
> - if (phydev->dev_flags & MICREL_PHY_50MHZ_CLK) {
> + if (phydev->dev_flags & (MICREL_PHY_50MHZ_CLK | MICREL_PHY_25MHZ_CLK)) {
> regval = phy_read(phydev, MII_KSZPHY_CTRL);
> - regval |= KSZ8051_RMII_50MHZ_CLK;
> + if (phydev->dev_flags & MICREL_PHY_50MHZ_CLK)
> + regval |= KSZ8051_RMII_50MHZ_CLK;
> + else
> + regval &= ~KSZ8051_RMII_50MHZ_CLK;
> return phy_write(phydev, MII_KSZPHY_CTRL, regval);
> }
> return 0;
> @@ -187,9 +191,20 @@ static int kszphy_config_init_led8041(struct phy_device *phydev)
>
> static int ksz8021_config_init(struct phy_device *phydev)
> {
> + struct clk *clk;
> const u16 val = KSZPHY_OMSO_B_CAST_OFF | KSZPHY_OMSO_RMII_OVERRIDE;
> int rc;
>
> + clk = devm_clk_get(&phydev->dev, "rmii-ref");
> + if (!IS_ERR(clk)) {
> + unsigned long rate = clk_get_rate(clk);
> +
> + if (rate > 24500000 && rate < 25500000)
> + phydev->dev_flags |= MICREL_PHY_25MHZ_CLK;
> + else if (rate > 49500000 && rate < 50500000)
> + phydev->dev_flags |= MICREL_PHY_50MHZ_CLK;
> + }

I suppose that you could move this to the PHY driver probe() callback,
and perform the rate checking from here, rejecting a clock whose rate is
out of the acceptable range, and return an error to prevent the PHY
driver registration? It is really up to you though.

> +
> rc = kszphy_setup_led(phydev, 0x1f, 4);
> if (rc)
> dev_err(&phydev->dev, "failed to set led mode\n");
> diff --git a/include/linux/micrel_phy.h b/include/linux/micrel_phy.h
> index 2e5b194..53d33de 100644
> --- a/include/linux/micrel_phy.h
> +++ b/include/linux/micrel_phy.h
> @@ -37,6 +37,7 @@
>
> /* struct phy_device dev_flags definitions */
> #define MICREL_PHY_50MHZ_CLK 0x00000001
> +#define MICREL_PHY_25MHZ_CLK 0x00000002
>
> #define MICREL_KSZ9021_EXTREG_CTRL 0xB
> #define MICREL_KSZ9021_EXTREG_DATA_WRITE 0xC
>



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