RE: [EXT] [PATCH 1/4] net: fec: set GPR bit on suspend by DT connfiguration.

[Andy Duan <fugang.duan@nxp.com>]

From: Martin Fuzzey <martin.fuzzey@flowbird.group> Sent: Wednesday, March 18, 2020 12:50 AM
> On some SoCs, such as the i.MX6, it is necessary to set a bit in the SoC level
> GPR register before suspending for wake on lan to work.
> 
> The fec platform callback sleep_mode_enable was intended to allow this but
> the platform implementation was NAK'd back in 2015 [1]
> 
> This means that, currently, wake on lan is broken on mainline for the i.MX6 at
> least.
> 
> So implement the required bit setting in the fec driver by itself by adding a
> new optional DT property indicating the register and bit to set.
> 
> [1]
> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.s
> pinics.net%2Flists%2Fnetdev%2Fmsg310922.html&amp;data=02%7C01%7Cf
> ugang.duan%40nxp.com%7Ca9e64936ec9f45edc57108d7ca9340dd%7C686e
> a1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C637200606109625887&am
> p;sdata=%2Bg4NIxZRwNY331k9cq5s6OIm22qD5qstiDIVlSQiL8E%3D&amp;res
> erved=0
> 
> Signed-off-by: Martin Fuzzey <martin.fuzzey@flowbird.group>
> ---
>  drivers/net/ethernet/freescale/fec.h      |  7 +++
>  drivers/net/ethernet/freescale/fec_main.c | 72
> ++++++++++++++++++++++++++++---
>  2 files changed, 72 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/net/ethernet/freescale/fec.h
> b/drivers/net/ethernet/freescale/fec.h
> index f79e57f..d89568f 100644
> --- a/drivers/net/ethernet/freescale/fec.h
> +++ b/drivers/net/ethernet/freescale/fec.h
> @@ -488,6 +488,12 @@ struct fec_enet_priv_rx_q {
>         struct  sk_buff *rx_skbuff[RX_RING_SIZE];  };
> 
> +struct fec_stop_mode_gpr {
> +       struct regmap *gpr;
> +       u8 reg;
> +       u8 bit;
> +};
> +
>  /* The FEC buffer descriptors track the ring buffers.  The rx_bd_base and
>   * tx_bd_base always point to the base of the buffer descriptors.  The
>   * cur_rx and cur_tx point to the currently available buffer.
> @@ -562,6 +568,7 @@ struct fec_enet_private {
>         int hwts_tx_en;
>         struct delayed_work time_keep;
>         struct regulator *reg_phy;
> +       struct fec_stop_mode_gpr stop_gpr;
> 
>         unsigned int tx_align;
>         unsigned int rx_align;
> diff --git a/drivers/net/ethernet/freescale/fec_main.c
> b/drivers/net/ethernet/freescale/fec_main.c
> index 23c5fef..3c78124 100644
> --- a/drivers/net/ethernet/freescale/fec_main.c
> +++ b/drivers/net/ethernet/freescale/fec_main.c
> @@ -62,6 +62,8 @@
>  #include <linux/if_vlan.h>
>  #include <linux/pinctrl/consumer.h>
>  #include <linux/prefetch.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/regmap.h>
>  #include <soc/imx/cpuidle.h>
> 
>  #include <asm/cacheflush.h>
> @@ -1092,11 +1094,28 @@ static void fec_enet_reset_skb(struct
> net_device *ndev)
> 
>  }
> 
> +static void fec_enet_stop_mode(struct fec_enet_private *fep, bool
> +enabled) {
> +       struct fec_platform_data *pdata = fep->pdev->dev.platform_data;
> +       struct fec_stop_mode_gpr *stop_gpr = &fep->stop_gpr;
> +
> +       if (stop_gpr->gpr) {
> +               if (enabled)
> +                       regmap_update_bits(stop_gpr->gpr,
> stop_gpr->reg,
> +                                          BIT(stop_gpr->bit),
> +                                          BIT(stop_gpr->bit));
> +               else
> +                       regmap_update_bits(stop_gpr->gpr,
> stop_gpr->reg,
> +                                          BIT(stop_gpr->bit), 0);
> +       } else if (pdata && pdata->sleep_mode_enable) {
> +               pdata->sleep_mode_enable(enabled);
> +       }
> +}
> +
>  static void
>  fec_stop(struct net_device *ndev)
>  {
>         struct fec_enet_private *fep = netdev_priv(ndev);
> -       struct fec_platform_data *pdata = fep->pdev->dev.platform_data;
>         u32 rmii_mode = readl(fep->hwp + FEC_R_CNTRL) & (1 << 8);
>         u32 val;
> 
> @@ -1125,9 +1144,7 @@ static void fec_enet_reset_skb(struct net_device
> *ndev)
>                 val = readl(fep->hwp + FEC_ECNTRL);
>                 val |= (FEC_ECR_MAGICEN | FEC_ECR_SLEEP);
>                 writel(val, fep->hwp + FEC_ECNTRL);
> -
> -               if (pdata && pdata->sleep_mode_enable)
> -                       pdata->sleep_mode_enable(true);
> +               fec_enet_stop_mode(fep, true);
>         }
>         writel(fep->phy_speed, fep->hwp + FEC_MII_SPEED);
> 
> @@ -3397,6 +3414,43 @@ static int fec_enet_get_irq_cnt(struct
> platform_device *pdev)
>         return irq_cnt;
>  }
> 
> +static int fec_enet_of_parse_stop_mode(struct fec_enet_private *fep,
> +                                      struct device_node *np) {
> +       static const char prop[] = "fsl,stop-mode";
> +       struct of_phandle_args args;
> +       int ret;
> +
> +       ret = of_parse_phandle_with_fixed_args(np, prop, 2, 0, &args);
To save memory:

		 ret = of_parse_phandle_with_fixed_args(np, "fsl,stop-mode", 2, 0, &args);

> +       if (ret == -ENOENT)
> +               return 0;
> +       if (ret)
> +               return ret;
> +
> +       if (args.args_count != 2) {
> +               dev_err(&fep->pdev->dev,
> +                       "Bad %s args want gpr offset, bit\n", prop);
> +               ret = -EINVAL;
> +               goto out;
> +       }
> +
> +       fep->stop_gpr.gpr = syscon_node_to_regmap(args.np);
> +       if (IS_ERR(fep->stop_gpr.gpr)) {
> +               dev_err(&fep->pdev->dev, "could not find gpr regmap\n");
> +               ret = PTR_ERR(fep->stop_gpr.gpr);
> +               fep->stop_gpr.gpr = NULL;
> +               goto out;
> +       }
> +
> +       fep->stop_gpr.reg = args.args[0];
> +       fep->stop_gpr.bit = args.args[1];
> +
> +out:
> +       of_node_put(args.np);
> +
> +       return ret;
> +}
> +
>  static int
>  fec_probe(struct platform_device *pdev)  { @@ -3463,6 +3517,10 @@
> static int fec_enet_get_irq_cnt(struct platform_device *pdev)
>         if (of_get_property(np, "fsl,magic-packet", NULL))
>                 fep->wol_flag |= FEC_WOL_HAS_MAGIC_PACKET;
> 
> +       ret = fec_enet_of_parse_stop_mode(fep, np);
> +       if (ret)
> +               goto failed_stop_mode;
> +
>         phy_node = of_parse_phandle(np, "phy-handle", 0);
>         if (!phy_node && of_phy_is_fixed_link(np)) {
>                 ret = of_phy_register_fixed_link(np); @@ -3631,6
> +3689,7 @@ static int fec_enet_get_irq_cnt(struct platform_device *pdev)
>         if (of_phy_is_fixed_link(np))
>                 of_phy_deregister_fixed_link(np);
>         of_node_put(phy_node);
> +failed_stop_mode:
>  failed_phy:
>         dev_id--;
>  failed_ioremap:
> @@ -3708,7 +3767,6 @@ static int __maybe_unused fec_resume(struct
> device *dev)  {
>         struct net_device *ndev = dev_get_drvdata(dev);
>         struct fec_enet_private *fep = netdev_priv(ndev);
> -       struct fec_platform_data *pdata = fep->pdev->dev.platform_data;
>         int ret;
>         int val;
> 
> @@ -3726,8 +3784,8 @@ static int __maybe_unused fec_resume(struct
> device *dev)
>                         goto failed_clk;
>                 }
>                 if (fep->wol_flag & FEC_WOL_FLAG_ENABLE) {
> -                       if (pdata && pdata->sleep_mode_enable)
> -                               pdata->sleep_mode_enable(false);
> +                       fec_enet_stop_mode(fep, false);
> +
>                         val = readl(fep->hwp + FEC_ECNTRL);
>                         val &= ~(FEC_ECR_MAGICEN |
> FEC_ECR_SLEEP);
>                         writel(val, fep->hwp + FEC_ECNTRL);
> --
> 1.9.1