[PATCH net-next v7 3/4] net: stmmac: Add DWMAC glue layer for Renesas GBETH

[Lad, Prabhakar]

Hi All,

On Wed, Apr 16, 2025 at 11:40 AM Prabhakar <prabhakar.csengg at gmail.com> wrote:
>
> From: Lad Prabhakar <prabhakar.mahadev-lad.rj at bp.renesas.com>
>
> Add the DWMAC glue layer for the GBETH IP found in the Renesas RZ/V2H(P)
> SoC.
>
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj at bp.renesas.com>
> Reviewed-by: Russell King (Oracle) <rmk+kernel at armlinux.org.uk>
> ---
>  drivers/net/ethernet/stmicro/stmmac/Kconfig   |  11 ++
>  drivers/net/ethernet/stmicro/stmmac/Makefile  |   1 +
>  .../stmicro/stmmac/dwmac-renesas-gbeth.c      | 146 ++++++++++++++++++
>  3 files changed, 158 insertions(+)
>  create mode 100644 drivers/net/ethernet/stmicro/stmmac/dwmac-renesas-gbeth.c
>
> diff --git a/drivers/net/ethernet/stmicro/stmmac/Kconfig b/drivers/net/ethernet/stmicro/stmmac/Kconfig
> index 3c820ef56775..2c99b23f0faa 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/Kconfig
> +++ b/drivers/net/ethernet/stmicro/stmmac/Kconfig
> @@ -131,6 +131,17 @@ config DWMAC_QCOM_ETHQOS
>           This selects the Qualcomm ETHQOS glue layer support for the
>           stmmac device driver.
>
> +config DWMAC_RENESAS_GBETH
> +       tristate "Renesas RZ/V2H(P) GBETH support"
> +       default ARCH_RENESAS
> +       depends on OF && (ARCH_RENESAS || COMPILE_TEST)
> +       help
> +         Support for Gigabit Ethernet Interface (GBETH) on Renesas
> +         RZ/V2H(P) SoCs.
> +
> +         This selects the Renesas RZ/V2H(P) Soc specific glue layer support
> +         for the stmmac device driver.
> +
>  config DWMAC_ROCKCHIP
>         tristate "Rockchip dwmac support"
>         default ARCH_ROCKCHIP
> diff --git a/drivers/net/ethernet/stmicro/stmmac/Makefile b/drivers/net/ethernet/stmicro/stmmac/Makefile
> index 594883fb4164..91050215511b 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/Makefile
> +++ b/drivers/net/ethernet/stmicro/stmmac/Makefile
> @@ -20,6 +20,7 @@ obj-$(CONFIG_DWMAC_LPC18XX)   += dwmac-lpc18xx.o
>  obj-$(CONFIG_DWMAC_MEDIATEK)   += dwmac-mediatek.o
>  obj-$(CONFIG_DWMAC_MESON)      += dwmac-meson.o dwmac-meson8b.o
>  obj-$(CONFIG_DWMAC_QCOM_ETHQOS)        += dwmac-qcom-ethqos.o
> +obj-$(CONFIG_DWMAC_RENESAS_GBETH) += dwmac-renesas-gbeth.o
>  obj-$(CONFIG_DWMAC_ROCKCHIP)   += dwmac-rk.o
>  obj-$(CONFIG_DWMAC_RZN1)       += dwmac-rzn1.o
>  obj-$(CONFIG_DWMAC_S32)                += dwmac-s32.o
> diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-renesas-gbeth.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-renesas-gbeth.c
> new file mode 100644
> index 000000000000..f34bec7794e2
> --- /dev/null
> +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-renesas-gbeth.c
> @@ -0,0 +1,146 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * dwmac-renesas-gbeth.c - DWMAC Specific Glue layer for Renesas GBETH
> + *
> + * The Rx and Tx clocks are supplied as follows for the GBETH IP.
> + *
> + *                         Rx / Tx
> + *   -------+------------- on / off -------
> + *          |
> + *          |            Rx-180 / Tx-180
> + *          +---- not ---- on / off -------
> + *
> + * Copyright (C) 2025 Renesas Electronics Corporation
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/device.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/reset.h>
> +
> +#include "stmmac_platform.h"
> +
> +struct renesas_gbeth {
> +       struct plat_stmmacenet_data *plat_dat;
> +       struct reset_control *rstc;
> +       struct device *dev;
> +};
> +
> +static const char *const renesas_gbeth_clks[] = {
> +       "tx", "tx-180", "rx", "rx-180",
> +};
> +
> +static int renesas_gbeth_init(struct platform_device *pdev, void *priv)
> +{
> +       struct plat_stmmacenet_data *plat_dat;
> +       struct renesas_gbeth *gbeth = priv;
> +       int ret;
> +
> +       plat_dat = gbeth->plat_dat;
> +
> +       ret = reset_control_deassert(gbeth->rstc);
> +       if (ret) {
> +               dev_err(gbeth->dev, "Reset deassert failed\n");
> +               return ret;
> +       }
> +
> +       ret = clk_bulk_prepare_enable(plat_dat->num_clks,
> +                                     plat_dat->clks);
> +       if (ret)
> +               reset_control_assert(gbeth->rstc);
> +
> +       return 0;
Just noticed this has to be ret, I'll send a new version fixing this.

Cheers,
Prabhakar