[PATCH net-next v6 3/4] net: stmmac: Add DWMAC glue layer for Renesas GBETH

[Lad, Prabhakar]

Hi Philipp,

Thank you for the review.

On Tue, Apr 15, 2025 at 2:38 PM Philipp Zabel <p.zabel at pengutronix.de> wrote:
>
> On Di, 2025-04-15 at 13:56 +0100, Prabhakar 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>
> > ---
> >  drivers/net/ethernet/stmicro/stmmac/Kconfig   |  11 ++
> >  drivers/net/ethernet/stmicro/stmmac/Makefile  |   1 +
> >  .../stmicro/stmmac/dwmac-renesas-gbeth.c      | 148 ++++++++++++++++++
> >  3 files changed, 160 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..8674b7605d83
> > --- /dev/null
> > +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-renesas-gbeth.c
> > @@ -0,0 +1,148 @@
> > +// 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;
> > +     void __iomem *regs;
>
> This doesn't seem to be used anywhere.
>
I'll get rid of it.

> > +};
> > +
> > +static const char *const renesas_gbeth_clks[] = {
> > +     "tx", "tx-180", "rx", "rx-180",
> > +};
> > +
> > +static int renesas_gbeth_clks_config(struct renesas_gbeth *gbeth, bool enabled)
> > +{
> > +     struct plat_stmmacenet_data *plat_dat;
> > +     int ret;
> > +
> > +     plat_dat = gbeth->plat_dat;
> > +     if (enabled) {
> > +             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);
> > +     } else {
> > +             clk_bulk_disable_unprepare(plat_dat->num_clks, plat_dat->clks);
> > +             ret = reset_control_assert(gbeth->rstc);
> > +             if (ret)
> > +                     dev_err(gbeth->dev, "Reset assert failed\n");
> > +     }
> > +
> > +     return ret;
> > +}
>
> Apart from the plat_dat assignment, this function has two completely
> separate paths. I'd fold its contents into renesas_gbeth_init/exit().
>
OK, I'll fix that in v7.

Cheers,
Prabhakar