[PATCH 1/2] of/phylib: Use device tree properties to initialize Marvell PHYs.
Grant Likely
grant.likely at secretlab.ca
Fri Nov 19 07:40:36 EST 2010
On Wed, Nov 17, 2010 at 03:54:30PM -0800, David Daney wrote:
> Some aspects of PHY initialization are board dependent, things like
> indicator LED connections and some clocking modes cannot be determined
> by probing. The dev_flags element of struct phy_device can be used to
> control these things if an appropriate value can be passed from the
> Ethernet driver. We run into problems however if the PHY connections
> are specified by the device tree. There is no way for the Ethernet
> driver to know what flags it should pass.
>
> If we are using the device tree, the struct phy_device will be
> populated with the device tree node corresponding to the PHY, and we
> can extract extra configuration information from there.
>
> The next question is what should the format of that information be?
> It is highly device specific, and the device tree representation
> should not be tied to any arbitrary kernel defined constants. A
> straight forward representation is just to specify the exact bits that
> should be set using the "marvell,reg-init" property:
>
> phy5: ethernet-phy at 5 {
> reg = <5>;
> device_type = "ethernet-phy";
Some notes:
- device_type is only relevant for real openfirmware platforms. It
should not appear in dts files.
- This example phy node needs a compatible property
- This new binding needs to be documented. You can use devicetree.org.
> marvell,reg-init =
> <0x00030010 0x5777>, /* Reg 3,16 <- 0x5777 */
> <0x00030011 0x00aa>, /* Reg 3,17 <- 0x00aa */
> <0x00030012 0x4105>, /* Reg 3,18 <- 0x4105 */
> <0x00030013 0x0060>; /* Reg 3,19 <- 0x0060 */
> <0x00020015 0x00300000>; /* clear bits 4..5 of Reg 2,21 */
> };
>
> The Marvell PHYs have a page select register at register 22 (0x16), we
> can specify any register by its page and register number. These are
> encoded in the high and low parts of the first word. The second word
> contains a mask and value to be ORed in its high and low parts. The
> new marvell_of_reg_init function leaves the page select register
> unchanged, so a call to it can be dropped into the .config_init
> functions without unduly affecting the state of the PHY.
Don't bother trying to pack the values tightly. Just use one cell per
value. ie: marvell,reg-init = < [page] [register] [mask] [value] >;
>
> If CONFIG_OF is not set, there is no of_node, or no "marvell,reg-init"
> property, the PHY initialization is unchanged.
>
> Signed-off-by: David Daney <ddaney at caviumnetworks.com>
> Cc: Grant Likely <grant.likely at secretlab.ca>
> Cc: Cyril Chemparathy <cyril at ti.com>
> Cc: David Daney <ddaney at caviumnetworks.com>
> Cc: Arnaud Patard <arnaud.patard at rtp-net.org>
> Cc: Benjamin Herrenschmidt <benh at kernel.crashing.org>
> ---
> drivers/net/phy/marvell.c | 91 +++++++++++++++++++++++++++++++++++++++++++++
> 1 files changed, 91 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/net/phy/marvell.c b/drivers/net/phy/marvell.c
> index f0bd1a1..33ad654 100644
> --- a/drivers/net/phy/marvell.c
> +++ b/drivers/net/phy/marvell.c
> @@ -30,6 +30,7 @@
> #include <linux/ethtool.h>
> #include <linux/phy.h>
> #include <linux/marvell_phy.h>
> +#include <linux/of.h>
>
> #include <asm/io.h>
> #include <asm/irq.h>
> @@ -186,6 +187,85 @@ static int marvell_config_aneg(struct phy_device *phydev)
> return 0;
> }
>
> +#ifndef CONFIG_OF
ifndef CONFIG_OF_MDIO
Nit: I usually see these blocks constructed the other way around. Put
the true case first, and then follow it up with the empty false case.
> +static int marvell_of_reg_init(struct phy_device *phydev)
> +{
> + return 0;
> +}
> +#else
> +/*
> + * Set and/or override some configuration registers based on the
> + * marvell,reg-init property stored in the of_node for the phydev.
> + *
> + * marvell,reg-init = <reg-spec val-spec>,...;
> + *
> + * There may be one or more pairs of <reg-spec val-spec>:
> + * reg-spec [16..31]: Page address.
> + * reg-spec [0..15]: Register address.
> + *
> + * val-spec [16..31]: Mask bits.
> + * val-spec [0..15]: Register bits.
> + */
> +static int marvell_of_reg_init(struct phy_device *phydev)
> +{
> + const __be32 *paddr;
> + int len, i, saved_page, current_page, page_changed, ret;
> +
> + if (!phydev->dev.of_node)
> + return 0;
> +
> + paddr = of_get_property(phydev->dev.of_node, "marvell,reg-init", &len);
> + if (!paddr || len < (2 * sizeof(u32)))
> + return 0;
> +
> + saved_page = phy_read(phydev, 22);
> + if (saved_page < 0)
> + return saved_page;
> + page_changed = 0;
> + current_page = saved_page;
> +
> + ret = 0;
> + len /= sizeof(u32);
> + for (i = 0; i < len / 2; i += 2) {
> + u32 reg_spec = be32_to_cpup(&paddr[i]);
> + u32 val_spec = be32_to_cpup(&paddr[i + 1]);
> + u16 reg = reg_spec & 0xffff;
> + u16 reg_page = reg_spec >> 16;
> + u16 val_bits = val_spec & 0xffff;
> + u16 mask = val_spec >> 16;
> + int val;
> +
> + if (reg_page != current_page) {
> + ret = phy_write(phydev, 22, reg_page);
> + if (ret < 0)
> + goto err;
> + current_page = reg_page;
> + page_changed = 1;
> + }
> +
> + val = 0;
> + if (mask) {
> + val = phy_read(phydev, reg);
> + if (val < 0) {
> + ret = val;
> + goto err;
> + }
> + val &= mask;
> + }
> + val |= val_bits;
> +
> + ret = phy_write(phydev, reg, (u16)val);
> + if (ret < 0)
> + goto err;
> +
> + }
> +err:
> + if (page_changed)
> + ret = phy_write(phydev, 22, saved_page);
This throws away the previous error code if a single write fails. It
may return a false success.
> + return ret;
> +}
> +#endif /* CONFIG_OF */
> +
> static int m88e1121_config_aneg(struct phy_device *phydev)
> {
> int err, oldpage, mscr;
> @@ -368,6 +448,9 @@ static int m88e1111_config_init(struct phy_device *phydev)
> return err;
> }
>
> + err = marvell_of_reg_init(phydev);
> + if (err < 0)
> + return err;
>
> err = phy_write(phydev, MII_BMCR, BMCR_RESET);
> if (err < 0)
> @@ -420,6 +503,10 @@ static int m88e1118_config_init(struct phy_device *phydev)
> if (err < 0)
> return err;
>
> + err = marvell_of_reg_init(phydev);
> + if (err < 0)
> + return err;
> +
> /* Reset address */
> err = phy_write(phydev, 0x16, 0x0);
> if (err < 0)
> @@ -491,6 +578,10 @@ static int m88e1145_config_init(struct phy_device *phydev)
> }
> }
>
> + err = marvell_of_reg_init(phydev);
> + if (err < 0)
> + return err;
> +
> return 0;
> }
>
> --
> 1.7.2.3
>
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