Re: [PATCH] net: stmmac: Add OXNAS Glue Driver

[Joachim Eastwood]

Hi Neil,

On 21 October 2016 at 10:44, Neil Armstrong <narmstrong@xxxxxxxxxxxx> wrote:
> Add Synopsys Designware MAC Glue layer for the Oxford Semiconductor OX820.
>
> Signed-off-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
> ---
>  .../devicetree/bindings/net/oxnas-dwmac.txt        |  44 +++++
>  drivers/net/ethernet/stmicro/stmmac/Kconfig        |  11 ++
>  drivers/net/ethernet/stmicro/stmmac/Makefile       |   1 +
>  drivers/net/ethernet/stmicro/stmmac/dwmac-oxnas.c  | 219 +++++++++++++++++++++
>  4 files changed, 275 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/net/oxnas-dwmac.txt
>  create mode 100644 drivers/net/ethernet/stmicro/stmmac/dwmac-oxnas.c
>
> Changes since RFC at https://patchwork.kernel.org/patch/9387257 :
>  - Drop init/exit callbacks
>  - Implement proper remove and PM callback
>  - Call init from probe
>  - Disable/Unprepare clock if stmmac probe fails

<snip>

> +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-oxnas.c
> @@ -0,0 +1,219 @@
> +/*
> + * Oxford Semiconductor OXNAS DWMAC glue layer
> + *
> + * Copyright (C) 2016 Neil Armstrong <narmstrong@xxxxxxxxxxxx>
> + * Copyright (C) 2014 Daniel Golle <daniel@xxxxxxxxxxxxxx>
> + * Copyright (C) 2013 Ma Haijun <mahaijuns@xxxxxxxxx>
> + * Copyright (C) 2012 John Crispin <blogic@xxxxxxxxxxx>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program. If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#include <linux/device.h>
> +#include <linux/io.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/stmmac.h>
> +
> +#include "stmmac_platform.h"
> +
> +/* System Control regmap offsets */
> +#define OXNAS_DWMAC_CTRL_REGOFFSET     0x78
> +#define OXNAS_DWMAC_DELAY_REGOFFSET    0x100
> +
> +/* Control Register */
> +#define DWMAC_CKEN_RX_IN        14
> +#define DWMAC_CKEN_RXN_OUT      13
> +#define DWMAC_CKEN_RX_OUT       12
> +#define DWMAC_CKEN_TX_IN        10
> +#define DWMAC_CKEN_TXN_OUT      9
> +#define DWMAC_CKEN_TX_OUT       8
> +#define DWMAC_RX_SOURCE         7
> +#define DWMAC_TX_SOURCE         6
> +#define DWMAC_LOW_TX_SOURCE     4
> +#define DWMAC_AUTO_TX_SOURCE    3
> +#define DWMAC_RGMII             2
> +#define DWMAC_SIMPLE_MUX        1
> +#define DWMAC_CKEN_GTX          0
> +
> +/* Delay register */
> +#define DWMAC_TX_VARDELAY_SHIFT                0
> +#define DWMAC_TXN_VARDELAY_SHIFT       8
> +#define DWMAC_RX_VARDELAY_SHIFT                16
> +#define DWMAC_RXN_VARDELAY_SHIFT       24
> +#define DWMAC_TX_VARDELAY(d)           ((d) << DWMAC_TX_VARDELAY_SHIFT)
> +#define DWMAC_TXN_VARDELAY(d)          ((d) << DWMAC_TXN_VARDELAY_SHIFT)
> +#define DWMAC_RX_VARDELAY(d)           ((d) << DWMAC_RX_VARDELAY_SHIFT)
> +#define DWMAC_RXN_VARDELAY(d)          ((d) << DWMAC_RXN_VARDELAY_SHIFT)
> +
> +struct oxnas_dwmac {
> +       struct device   *dev;
> +       struct clk      *clk;
> +       struct regmap   *regmap;
> +};
> +
> +static int oxnas_dwmac_init(struct oxnas_dwmac *dwmac)
> +{
> +       unsigned int value;
> +       int ret;
> +
> +       /* Reset HW here before changing the glue configuration */
> +       ret = device_reset(dwmac->dev);
> +       if (ret)
> +               return ret;
> +
> +       clk_prepare_enable(dwmac->clk);

You might want to check the return value from clk_prepare_enable() as well.

> +
> +       ret = regmap_read(dwmac->regmap, OXNAS_DWMAC_CTRL_REGOFFSET, &value);
> +       if (ret < 0)
> +               return ret;
> +
> +       /* Enable GMII_GTXCLK to follow GMII_REFCLK, required for gigabit PHY */
> +       value |= BIT(DWMAC_CKEN_GTX);
> +       /* Use simple mux for 25/125 Mhz clock switching */
> +       value |= BIT(DWMAC_SIMPLE_MUX);
> +       /* set auto switch tx clock source */
> +       value |= BIT(DWMAC_AUTO_TX_SOURCE);
> +       /* enable tx & rx vardelay */
> +       value |= BIT(DWMAC_CKEN_TX_OUT);
> +       value |= BIT(DWMAC_CKEN_TXN_OUT);
> +       value |= BIT(DWMAC_CKEN_TX_IN);
> +       value |= BIT(DWMAC_CKEN_RX_OUT);
> +       value |= BIT(DWMAC_CKEN_RXN_OUT);
> +       value |= BIT(DWMAC_CKEN_RX_IN);
> +       regmap_write(dwmac->regmap, OXNAS_DWMAC_CTRL_REGOFFSET, value);
> +
> +       /* set tx & rx vardelay */
> +       value = DWMAC_TX_VARDELAY(4);
> +       value |= DWMAC_TXN_VARDELAY(2);
> +       value |= DWMAC_RX_VARDELAY(10);
> +       value |= DWMAC_RXN_VARDELAY(8);
> +       regmap_write(dwmac->regmap, OXNAS_DWMAC_DELAY_REGOFFSET, value);
> +
> +       return 0;
> +}
> +
> +static int oxnas_dwmac_probe(struct platform_device *pdev)
> +{
> +       struct plat_stmmacenet_data *plat_dat;
> +       struct stmmac_resources stmmac_res;
> +       struct device_node *sysctrl;
> +       struct oxnas_dwmac *dwmac;
> +       int ret;
> +
> +       sysctrl = of_parse_phandle(pdev->dev.of_node, "oxsemi,sys-ctrl", 0);
> +       if (!sysctrl) {
> +               dev_err(&pdev->dev, "failed to get sys-ctrl node\n");
> +               return -EINVAL;
> +       }
> +
> +       ret = stmmac_get_platform_resources(pdev, &stmmac_res);
> +       if (ret)
> +               return ret;
> +
> +       plat_dat = stmmac_probe_config_dt(pdev, &stmmac_res.mac);
> +       if (IS_ERR(plat_dat))
> +               return PTR_ERR(plat_dat);
> +
> +       dwmac = devm_kzalloc(&pdev->dev, sizeof(*dwmac), GFP_KERNEL);
> +       if (!dwmac)
> +               return -ENOMEM;
> +
> +       dwmac->dev = &pdev->dev;
> +       plat_dat->bsp_priv = dwmac;
> +
> +       dwmac->regmap = syscon_node_to_regmap(sysctrl);
> +       if (IS_ERR(dwmac->regmap)) {
> +               dev_err(&pdev->dev, "failed to have sysctrl regmap\n");
> +               return PTR_ERR(dwmac->regmap);
> +       }
> +
> +       dwmac->clk = devm_clk_get(&pdev->dev, "gmac");
> +       if (IS_ERR(dwmac->clk))
> +               return PTR_ERR(dwmac->clk);
> +
> +       ret = oxnas_dwmac_init(dwmac);
> +       if (ret)
> +               return ret;
> +
> +       ret = stmmac_dvr_probe(&pdev->dev, plat_dat, &stmmac_res);
> +       if (ret)
> +               clk_disable_unprepare(dwmac->clk);
> +
> +       return ret;
> +}
> +
> +static int oxnas_dwmac_remove(struct platform_device *pdev)
> +{
> +       struct net_device *ndev = platform_get_drvdata(pdev);
> +       struct stmmac_priv *priv = netdev_priv(ndev);
> +       struct oxnas_dwmac *dwmac = priv->plat->bsp_priv;

Instead of this long dance of variables use the get_stmmac_bsp_priv()-helper.

You can take a look at dwmac-meson8b.c for reference.


> +       int ret = stmmac_dvr_remove(&pdev->dev);
> +
> +       clk_disable_unprepare(dwmac->clk);
> +
> +       return ret;
> +}
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int oxnas_dwmac_suspend(struct device *dev)
> +{
> +       struct net_device *ndev = dev_get_drvdata(dev);
> +       struct stmmac_priv *priv = netdev_priv(ndev);
> +       struct oxnas_dwmac *dwmac = priv->plat->bsp_priv;

get_stmmac_bsp_priv()


> +       int ret;
> +
> +       ret = stmmac_suspend(dev);
> +       clk_disable_unprepare(dwmac->clk);
> +
> +       return ret;
> +}
> +
> +static int oxnas_dwmac_resume(struct device *dev)
> +{
> +       struct net_device *ndev = dev_get_drvdata(dev);
> +       struct stmmac_priv *priv = netdev_priv(ndev);
> +       struct oxnas_dwmac *dwmac = priv->plat->bsp_priv;

get_stmmac_bsp_priv()


> +       int ret;
> +
> +       ret = oxnas_dwmac_init(dwmac);
> +       if (ret)
> +               return ret;
> +
> +       ret = stmmac_resume(dev);
> +
> +       return ret;
> +}
> +#endif /* CONFIG_PM_SLEEP */

With these changes:
Acked-by: Joachim Eastwood <manabian@xxxxxxxxx>


best regards,
Joachim Eastwood