Subject: Re: [PATCH v3] ethernet: arc: Add support for Rockchip SoC layer device tree bindings

From: Heiko Stübner <[email-masked]>
Date: Mon, 01 Sep 2014 17:32:23 +0200

Am Montag, 1. September 2014, 08:33:27 schrieb Romain Perier:
> This patch defines a platform glue layer for Rockchip SoCs which
> support arc-emac driver. It ensures that regulator for the rmii is on
> before trying to connect to the ethernet controller. It applies right
> speed and mode changes to the grf when ethernet settings change.
> 
> Signed-off-by: Romain Perier <[email-masked]>

As we already talked about in irc, the dt-binding document is missing

> ---
>  drivers/net/ethernet/arc/Kconfig         |  10 ++
>  drivers/net/ethernet/arc/Makefile        |   1 +
>  drivers/net/ethernet/arc/emac.h          |   4 +-
>  drivers/net/ethernet/arc/emac_main.c     |   2 +
>  drivers/net/ethernet/arc/emac_rockchip.c | 224
> +++++++++++++++++++++++++++++++ 5 files changed, 240 insertions(+), 1
> deletion(-)
>  create mode 100644 drivers/net/ethernet/arc/emac_rockchip.c
> 
> diff --git a/drivers/net/ethernet/arc/Kconfig
> b/drivers/net/ethernet/arc/Kconfig index 89e04fd..0c0063b 100644
> --- a/drivers/net/ethernet/arc/Kconfig
> +++ b/drivers/net/ethernet/arc/Kconfig
> @@ -32,4 +32,14 @@ config ARC_EMAC
>  	  non-standard on-chip ethernet device ARC EMAC 10/100 is used.
>  	  Say Y here if you have such a board.  If unsure, say N.
> 
> +config EMAC_ROCKCHIP
> +       tristate "Rockchip EMAC support"
> +       select ARC_EMAC_CORE
> +       depends on OF_IRQ && OF_NET && REGULATOR
> +       ---help---
> +         Support for Rockchip RK3066/RK3188 EMAC ethernet controllers.
> +         This selects Rockchip SoC glue layer support for the
> +         emac device driver. This driver is used for RK3066/RK3188
> +         EMAC ethernet controller.
> +

the other entries use tabs for the initial indentation here

>  endif # NET_VENDOR_ARC
> diff --git a/drivers/net/ethernet/arc/Makefile
> b/drivers/net/ethernet/arc/Makefile index 241bb80..79108af 100644
> --- a/drivers/net/ethernet/arc/Makefile
> +++ b/drivers/net/ethernet/arc/Makefile
> @@ -5,3 +5,4 @@
>  arc_emac-objs := emac_main.o emac_mdio.o
>  obj-$(CONFIG_ARC_EMAC_CORE) += arc_emac.o
>  obj-$(CONFIG_ARC_EMAC) += emac_arc.o
> +obj-$(CONFIG_EMAC_ROCKCHIP) += emac_rockchip.o
> diff --git a/drivers/net/ethernet/arc/emac.h
> b/drivers/net/ethernet/arc/emac.h index eb2ba67..dae1ac3 100644
> --- a/drivers/net/ethernet/arc/emac.h
> +++ b/drivers/net/ethernet/arc/emac.h
> @@ -123,9 +123,11 @@ struct buffer_state {
>   * @speed:	PHY's last set speed.
>   */
>  struct arc_emac_priv {
> -	/* Devices */
>  	const char *drv_name;
>  	const char *drv_version;
> +	void (*set_mac_speed)(void *priv, unsigned int speed);
> +
> +	/* Devices */
>  	struct device *dev;
>  	struct phy_device *phy_dev;
>  	struct mii_bus *bus;
> diff --git a/drivers/net/ethernet/arc/emac_main.c
> b/drivers/net/ethernet/arc/emac_main.c index b35c69e..a08f343 100644
> --- a/drivers/net/ethernet/arc/emac_main.c
> +++ b/drivers/net/ethernet/arc/emac_main.c
> @@ -48,6 +48,8 @@ static void arc_emac_adjust_link(struct net_device *ndev)
>  	if (priv->speed != phy_dev->speed) {
>  		priv->speed = phy_dev->speed;
>  		state_changed = 1;
> +		if (priv->set_mac_speed)
> +			priv->set_mac_speed(priv, priv->speed);
>  	}
> 
>  	if (priv->duplex != phy_dev->duplex) {
> diff --git a/drivers/net/ethernet/arc/emac_rockchip.c
> b/drivers/net/ethernet/arc/emac_rockchip.c new file mode 100644
> index 0000000..d1d367a
> --- /dev/null
> +++ b/drivers/net/ethernet/arc/emac_rockchip.c
> @@ -0,0 +1,224 @@
> +/**
> + * emac-rockchip.c - Rockchip EMAC specific glue layer
> + *
> + * Copyright (C) 2014 Romain Perier
> + *
> + * Romain Perier  <[email-masked]>

these 3 could simply be one line:

Copyright (C) 2014 Romain Perier <[email-masked]>

> + *
> + * 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.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/etherdevice.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/module.h>
> +#include <linux/of_net.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/regulator/consumer.h>
> +
> +#include "emac.h"
> +
> +#define DRV_NAME        "rockchip_emac"
> +#define DRV_VERSION     "1.0"
> +
> +#define GRF_MODE_MII         (1UL << 0)
> +#define GRF_MODE_RMII        (0UL << 0)
> +#define GRF_SPEED_10M        (0UL << 1)
> +#define GRF_SPEED_100M       (1UL << 1)
> +#define GRF_SPEED_ENABLE_BIT (1UL << 17)
> +#define GRF_MODE_ENABLE_BIT  (1UL << 16)

personally I'd use tabs here to align the two columns

> +
> +struct emac_rockchip_soc_data {
> +	int grf_offset;
> +};
> +
> +struct rockchip_priv_data {
> +	struct arc_emac_priv emac;
> +	struct regmap *grf;
> +	const struct emac_rockchip_soc_data *soc_data;
> +	struct regulator *regulator;
> +	struct clk *refclk;
> +};
> +
> +static const struct emac_rockchip_soc_data emac_rockchip_dt_data[] = {
> +	{ .grf_offset = 0x154 }, /* rk3066 */
> +	{ .grf_offset = 0x0a4 }, /* rk3188 */
> +};
> +
> +static const struct of_device_id emac_rockchip_dt_ids[] = {
> +	{ .compatible = "rockchip,rk3066-emac", .data = &emac_rockchip_dt_data[0]},
> +	{ .compatible = "rockchip,rk3188-emac", .data = &emac_rockchip_dt_data[1]},

space before closing "}"

> +	{ /* Sentinel */ }
> +};
> +
> +static void emac_rockchip_set_mac_speed(void *priv, unsigned int speed)
> +{
> +	struct rockchip_priv_data *emac = priv;
> +	u32 data;
> +	int err = 0;
> +
> +	/* write-enable bits */
> +	data = GRF_SPEED_ENABLE_BIT;
> +
> +	switch(speed) {
> +	case 10:
> +		data |= GRF_SPEED_10M;
> +		break;
> +	case 100:
> +		data |= GRF_SPEED_100M;
> +		break;
> +	default:
> +		pr_err("speed %u not supported\n", speed);
> +		return;
> +	}
> +
> +	err = regmap_write(emac->grf, emac->soc_data->grf_offset, data);
> +	if (err)
> +		pr_err("unable to apply speed %u to grf (%d)\n", speed, err);
> +}
> +
> +static int emac_rockchip_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct net_device *ndev;
> +	struct rockchip_priv_data *priv;
> +	const struct of_device_id *match;
> +	u32 data;
> +	int err, interface;
> +
> +	if (!pdev->dev.of_node)
> +		return -ENODEV;
> +
> +	ndev = alloc_etherdev(sizeof(struct rockchip_priv_data));
> +	if (!ndev)
> +		return -ENOMEM;
> +	platform_set_drvdata(pdev, ndev);
> +	SET_NETDEV_DEV(ndev, dev);
> +
> +	priv = netdev_priv(ndev);
> +	priv->emac.drv_name = DRV_NAME;
> +	priv->emac.drv_version = DRV_VERSION;
> +	priv->emac.set_mac_speed = emac_rockchip_set_mac_speed;
> +
> +	interface = of_get_phy_mode(dev->of_node);
> +
> +	/* RK3066 and RK3188 SoCs only support RMII */
> +	if (interface != PHY_INTERFACE_MODE_RMII) {
> +		dev_err(dev, "unsupported phy interface mode %d\n", interface);
> +		err = -ENOTSUPP;
> +		goto out_netdev;
> +	}
> +
> +	priv->grf = syscon_regmap_lookup_by_phandle(dev->of_node, "rockchip,grf");
> +	if (IS_ERR(priv->grf)) {
> +		dev_err(dev, "failed to retrieve global register file from the device
> tree (%ld)\n", PTR_ERR(priv->grf)); +		err = PTR_ERR(priv->grf);
> +		goto out_netdev;
> +	}
> +
> +	match = of_match_node(emac_rockchip_dt_ids, dev->of_node);
> +	priv->soc_data = match->data;
> +
> +	priv->emac.clk = devm_clk_get(dev, "hclk");
> +	if (IS_ERR(priv->emac.clk)) {
> +		dev_err(dev, "failed to retrieve host clock from device tree (%ld)\n",
> PTR_ERR(priv->emac.clk)); +		err = PTR_ERR(priv->emac.clk);
> +		goto out_netdev;
> +	}
> +
> +	priv->refclk = devm_clk_get(dev, "macref");
> +	if (IS_ERR(priv->refclk)) {
> +		dev_err(dev, "failed to retrieve reference clock from device tree
> (%ld)\n", PTR_ERR(priv->refclk)); +		err = PTR_ERR(priv->refclk);
> +		goto out_netdev;
> +	}
> +
> +	err = clk_prepare_enable(priv->refclk);
> +	if (err) {
> +		dev_err(dev, "failed to enable reference clock (%d)\n", err);
> +		goto out_netdev;
> +	}
> +
> +        /* Optional regulator for PHY */

spaces as indentation here, please use a tab instead

> +	priv->regulator = devm_regulator_get_optional(dev, "phy");
> +	if (IS_ERR(priv->regulator)) {
> +		if (PTR_ERR(priv->regulator) == -EPROBE_DEFER)
> +			return -EPROBE_DEFER;
> +		dev_err(dev, "no regulator found\n");
> +		priv->regulator = NULL;
> +	}
> +
> +	if (priv->regulator) {
> +		err = regulator_enable(priv->regulator);
> +		if (err) {
> +			dev_err(dev, "failed to enable phy-supply (%d)\n", err);
> +			goto out_netdev;

goto out_clk_disable;

> +		}
> +	}
> +
> +	err = arc_emac_probe(ndev, interface);
> +	if (err)
> +		goto out_netdev;

goto out_reg_disable;

> +
> +	/* write-enable bits */
> +	data = GRF_MODE_ENABLE_BIT | GRF_SPEED_ENABLE_BIT;
> +
> +	data |= GRF_SPEED_100M;
> +	data |= GRF_MODE_RMII;
> +
> +	err = regmap_write(priv->grf, priv->soc_data->grf_offset, data);
> +	if (err) {
> +		dev_err(dev, "unable to apply initial settings to grf (%d)\n", err);
> +		goto out_netdev;

goto out_reg_disable;

> +	}
> +
> +	/* RMII interface needs always a rate of 50MHz */
> +	err = clk_set_rate(priv->refclk, 50000000);
> +	if (err)
> +		dev_err(dev, "failed to change reference clock rate (%d)\n", err);
> +

	err = clk_set_rate(priv->refclk, 50000000);
	if (err) {
		dev_err(dev, "failed to change reference clock rate (%d)\n", err);
		goto out_reg_disable;
	}

	return 0;

out_reg_disable:
	if (priv->regulator)
		regulator_disable(priv->regulator);
out_clk_disable:
	clk_disable_unprepare(priv->refclk);
out_netdev:
	free_netdev(ndev);
	return err;

> +out_netdev:
> +	if (err)
> +		free_netdev(ndev);
> +	return err;
> +}
> +
> +static int emac_rockchip_remove(struct platform_device *pdev)
> +{
> +	struct net_device *ndev = platform_get_drvdata(pdev);
> +	struct rockchip_priv_data *priv = netdev_priv(ndev);
> +	int err;
> +
> +	clk_disable_unprepare(priv->refclk);
> +
> +	if (priv->regulator)
> +		regulator_disable(priv->regulator);

blank line

> +	err = arc_emac_remove(ndev);
> +	free_netdev(ndev);
> +	return err;
> +}
> +
> +MODULE_DEVICE_TABLE(of, emac_rockchip_dt_ids);
> +
> +static struct platform_driver emac_rockchip_driver = {
> +	.probe = emac_rockchip_probe,
> +	.remove = emac_rockchip_remove,
> +	.driver = {
> +		.name = DRV_NAME,
> +		.of_match_table  = emac_rockchip_dt_ids,
> +	},
> +};
> +
> +module_platform_driver(emac_rockchip_driver);
> +
> +MODULE_AUTHOR("Romain Perier <[email-masked]>");
> +MODULE_DESCRIPTION("Rockchip EMAC platform driver");
> +MODULE_LICENSE("GPL");