Re: [PATCH 1/1 RFC] net/phy: Add Lantiq PHY driver

From: Florian Fainelli
Date: Wed May 18 2016 - 12:24:33 EST


CC'ing Andrew, John,

On 05/18/2016 09:03 AM, Alexander Stein wrote:
> This currently only supports PEF7071 and allows to specify max-speed and
> is able to read the LED configuration from device-tree.
>
> Signed-off-by: Alexander Stein <alexander.stein@xxxxxxxxxxxxxxxxxxxxx>
> ---
> The main purpose for now is to set a LED configuration from device tree and
> to limit the maximum speed. The latter one in my case hardware limited.
> As MAC and it's link partner support 1000MBit/s they would try to use that
> but will eventually fail due to magnetics only supporting 100MBit/s. So
> limit the maximum link speed supported directly from the start.

The 'max-speed' parsing that you do in the driver should not be needed,
PHYLIB takes care of that already see
drivers/net/phy/phy_device.c::of_set_phy_supported

For LEDs, we had a patch series floating around adding LED triggers [1],
and it seems to me like the LEDs class subsystem would be a good fit for
controlling PHY LEDs, possibly with the help of PHYLIB when it comes to
doing the low-level work of registering LEDs and their names with the
LEDS subsystem.

[1]: http://lists.openwall.net/netdev/2016/03/23/61

>
> As this is a RFC I skipped the device tree binding doc.

Too bad, that's probably what needs to be discussed here, because the
driver looks pretty reasonable otherwise.

>
> drivers/net/phy/Kconfig | 5 ++
> drivers/net/phy/Makefile | 1 +
> drivers/net/phy/lantiq.c | 167 +++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 173 insertions(+)
> create mode 100644 drivers/net/phy/lantiq.c
>
> diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
> index 3e28f7a..c004885 100644
> --- a/drivers/net/phy/Kconfig
> +++ b/drivers/net/phy/Kconfig
> @@ -119,6 +119,11 @@ config STE10XP
> ---help---
> This is the driver for the STe100p and STe101p PHYs.
>
> +config LANTIQ_PHY
> + tristate "Driver for Lantiq PHYs"
> + ---help---
> + Supports the PEF7071 PHYs.
> +
> config LSI_ET1011C_PHY
> tristate "Driver for LSI ET1011C PHY"
> ---help---
> diff --git a/drivers/net/phy/Makefile b/drivers/net/phy/Makefile
> index 8ad4ac6..e886549 100644
> --- a/drivers/net/phy/Makefile
> +++ b/drivers/net/phy/Makefile
> @@ -38,3 +38,4 @@ obj-$(CONFIG_MDIO_SUN4I) += mdio-sun4i.o
> obj-$(CONFIG_MDIO_MOXART) += mdio-moxart.o
> obj-$(CONFIG_AMD_XGBE_PHY) += amd-xgbe-phy.o
> obj-$(CONFIG_MDIO_BCM_UNIMAC) += mdio-bcm-unimac.o
> +obj-$(CONFIG_LANTIQ_PHY) += lantiq.o
> diff --git a/drivers/net/phy/lantiq.c b/drivers/net/phy/lantiq.c
> new file mode 100644
> index 0000000..876a7d1
> --- /dev/null
> +++ b/drivers/net/phy/lantiq.c
> @@ -0,0 +1,167 @@
> +/*
> + * Driver for Lantiq PHYs
> + *
> + * Author: Alexander Stein <alexander.stein@xxxxxxxxxxxxxxxxxxxxx>
> + *
> + * Copyright (c) 2015-2016 SYS TEC electronic GmbH
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License as published by the
> + * Free Software Foundation; either version 2 of the License, or (at your
> + * option) any later version.
> + *
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/phy.h>
> +#include <linux/of.h>
> +
> +#define PHY_ID_PEF7071 0xd565a401
> +
> +#define MII_LANTIQ_MMD_CTRL_REG 0x0d
> +#define MII_LANTIQ_MMD_REGDATA_REG 0x0e
> +#define OP_DATA 1
> +
> +struct lantiqphy_led_ctrl {
> + const char *property;
> + u32 regnum;
> +};
> +
> +static int lantiq_extended_write(struct phy_device *phydev,
> + u8 mode, u32 dev_addr, u32 regnum, u16 val)
> +{
> + phy_write(phydev, MII_LANTIQ_MMD_CTRL_REG, dev_addr);
> + phy_write(phydev, MII_LANTIQ_MMD_REGDATA_REG, regnum);
> + phy_write(phydev, MII_LANTIQ_MMD_CTRL_REG, (mode << 14) | dev_addr);
> + return phy_write(phydev, MII_LANTIQ_MMD_REGDATA_REG, val);
> +}
> +
> +static int lantiq_of_load_led_config(struct phy_device *phydev,
> + struct device_node *of_node,
> + const struct lantiqphy_led_ctrl *leds,
> + u8 entries)
> +{
> + u16 val;
> + int i;
> + int ret = 0;
> +
> + for (i = 0; i < entries; i++) {
> + if (!of_property_read_u16(of_node, leds[i].property, &val)) {
> + ret = lantiq_extended_write(phydev, OP_DATA, 0x1f,
> + leds[i].regnum, val);
> + if (ret) {
> + dev_err(&phydev->dev, "Error writing register 0x1f.%04x (%d)\n",
> + leds[i].regnum, ret);
> + break;
> + }
> + }
> + }
> +
> + return ret;
> +}
> +
> +static const struct lantiqphy_led_ctrl leds[] = {
> + {
> + .property = "led0h",
> + .regnum = 0x01e2,
> + },
> + {
> + .property = "led0l",
> + .regnum = 0x01e3,
> + },
> + {
> + .property = "led1h",
> + .regnum = 0x01e4,
> + },
> + {
> + .property = "led1l",
> + .regnum = 0x01e5,
> + },
> + {
> + .property = "led2h",
> + .regnum = 0x01e6,
> + },
> + {
> + .property = "led2l",
> + .regnum = 0x01e7,
> + },
> +};
> +
> +static int lantiqphy_config_init(struct phy_device *phydev)
> +{
> + struct device *dev = &phydev->dev;
> + struct device_node *of_node = dev->of_node;
> + u32 max_speed;
> +
> + if (!of_node && dev->parent->of_node)
> + of_node = dev->parent->of_node;
> +
> + if (of_node) {
> + lantiq_of_load_led_config(phydev, of_node, leds,
> + ARRAY_SIZE(leds));
> +
> + if (!of_property_read_u32(of_node, "max-speed",
> + &max_speed)) {
> + /* The default values for phydev->supported are
> + * provided by the PHY driver "features" member,
> + * we want to reset to sane defaults fist before
> + * supporting higher speeds.
> + */
> + phydev->supported &= PHY_DEFAULT_FEATURES;
> +
> + switch (max_speed) {
> + default:
> + break;
> +
> + case SPEED_1000:
> + phydev->supported |= PHY_1000BT_FEATURES;
> + case SPEED_100:
> + phydev->supported |= PHY_100BT_FEATURES;
> + case SPEED_10:
> + phydev->supported |= PHY_10BT_FEATURES;
> + }
> + }
> + }
> + return 0;
> +}
> +
> +static struct phy_driver lantiqphy_driver[] = {
> +{
> + .phy_id = PHY_ID_PEF7071,
> + .phy_id_mask = 0x00fffffe,
> + .name = "Lantiq PEF7071",
> + .features = (PHY_GBIT_FEATURES | SUPPORTED_Pause),
> + .flags = PHY_HAS_MAGICANEG,
> + .config_init = lantiqphy_config_init,
> + .config_aneg = genphy_config_aneg,
> + .read_status = genphy_read_status,
> + .suspend = genphy_suspend,
> + .resume = genphy_resume,
> + .driver = { .owner = THIS_MODULE,},
> +} };
> +
> +static int __init lantiqphy_init(void)
> +{
> + return phy_drivers_register(lantiqphy_driver,
> + ARRAY_SIZE(lantiqphy_driver));
> +}
> +
> +static void __exit lantiqphy_exit(void)
> +{
> + phy_drivers_unregister(lantiqphy_driver,
> + ARRAY_SIZE(lantiqphy_driver));
> +}
> +
> +module_init(lantiqphy_init);
> +module_exit(lantiqphy_exit);
> +
> +MODULE_DESCRIPTION("Lantiq PHY driver");
> +MODULE_AUTHOR("Alexander Stein <alexander.stein@xxxxxxxxxxxxxxxxxxxxx>");
> +MODULE_LICENSE("GPL");
> +
> +static struct mdio_device_id __maybe_unused lantiq_tbl[] = {
> + { PHY_ID_PEF7071, 0x00fffffe },
> + { }
> +};
> +MODULE_DEVICE_TABLE(mdio, lantiq_tbl);
>


--
Florian