Re: [PATCH net-next v3 3/3] net: stmmac: Add DWMAC glue layer for Renesas GBETH

[Paolo Abeni]

On 3/11/25 11:17 PM, Prabhakar wrote:
> @@ -0,0 +1,166 @@
> +// 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 "dwmac4.h"
> +#include "stmmac_platform.h"
> +
> +struct renesas_gbeth {
> +	struct plat_stmmacenet_data *plat_dat;
> +	struct reset_control *rstc;
> +	struct device *dev;
> +	void __iomem *regs;
> +};
> +
> +static const char *const renesas_gbeth_clks[] = {
> +	"tx", "tx-180", "rx", "rx-180",
> +};
> +
> +static struct clk *renesas_gbeth_find_clk(struct plat_stmmacenet_data *plat_dat,
> +					  const char *name)
> +{
> +	for (unsigned int i = 0; i < plat_dat->num_clks; i++)
> +		if (!strcmp(plat_dat->clks[i].id, name))
> +			return plat_dat->clks[i].clk;
> +
> +	return NULL;
> +}
> +
> +static int renesas_gbeth_clks_config(void *priv, bool enabled)
> +{
> +	struct renesas_gbeth *gbeth = priv;
> +	struct plat_stmmacenet_data *plat_dat = gbeth->plat_dat;

Minor nit: please respect the reverse christmas tree order above:

	struct plat_stmmacenet_data *plat_dat;
	struct renesas_gbeth *gbeth = priv;

and init plat_dat later.

> +	int ret;
> +
> +	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;
> +}
> +
> +static int renesas_gbeth_probe(struct platform_device *pdev)
> +{
> +	struct plat_stmmacenet_data *plat_dat;
> +	struct stmmac_resources stmmac_res;
> +	struct device *dev = &pdev->dev;
> +	struct renesas_gbeth *gbeth;
> +	unsigned int i;
> +	int err;
> +
> +	err = stmmac_get_platform_resources(pdev, &stmmac_res);
> +	if (err)
> +		return dev_err_probe(dev, err,
> +				     "failed to get resources\n");
> +
> +	plat_dat = devm_stmmac_probe_config_dt(pdev, stmmac_res.mac);
> +	if (IS_ERR(plat_dat))
> +		return dev_err_probe(dev, PTR_ERR(plat_dat),
> +				     "dt configuration failed\n");
> +
> +	gbeth = devm_kzalloc(dev, sizeof(*gbeth), GFP_KERNEL);
> +	if (!gbeth)
> +		return -ENOMEM;
> +
> +	plat_dat->num_clks = ARRAY_SIZE(renesas_gbeth_clks);
> +	plat_dat->clks = devm_kcalloc(dev, plat_dat->num_clks,
> +				      sizeof(*plat_dat->clks), GFP_KERNEL);
> +	if (!plat_dat->clks)
> +		return -ENOMEM;
> +
> +	for (i = 0; i < plat_dat->num_clks; i++)
> +		plat_dat->clks[i].id = renesas_gbeth_clks[i];
> +
> +	err = devm_clk_bulk_get(dev, plat_dat->num_clks, plat_dat->clks);
> +	if (err < 0)
> +		return err;
> +
> +	plat_dat->clk_tx_i = renesas_gbeth_find_clk(plat_dat, "tx");
> +	if (!plat_dat->clk_tx_i)
> +		return dev_err_probe(dev, -EINVAL,
> +				     "error finding tx clock\n");
> +
> +	gbeth->rstc = devm_reset_control_get_exclusive(dev, NULL);
> +	if (IS_ERR(gbeth->rstc))
> +		return PTR_ERR(gbeth->rstc);
> +
> +	gbeth->dev = dev;
> +	gbeth->regs = stmmac_res.addr;
> +	gbeth->plat_dat = plat_dat;
> +	plat_dat->bsp_priv = gbeth;
> +	plat_dat->set_clk_tx_rate = stmmac_set_clk_tx_rate;
> +	plat_dat->clks_config = renesas_gbeth_clks_config;
> +	plat_dat->flags |= STMMAC_FLAG_HWTSTAMP_CORRECT_LATENCY |
> +			   STMMAC_FLAG_EN_TX_LPI_CLK_PHY_CAP |

The above does not compile:

../drivers/net/ethernet/stmicro/stmmac/dwmac-renesas-gbeth.c:124:7:
error: use of undeclared identifier 'STMMAC_FLAG_EN_TX_LPI_CLK_PHY_CAP'


> +			   STMMAC_FLAG_SPH_DISABLE;
> +
> +	err = renesas_gbeth_clks_config(gbeth, true);
> +	if (err)
> +		return err;
> +
> +	err = stmmac_dvr_probe(dev, plat_dat, &stmmac_res);
> +	if (err) {
> +		renesas_gbeth_clks_config(gbeth, false);
> +		return err;

Just:

	if (err)
		renesas_gbeth_clks_config(gbeth, false);

	return err;

Thanks,

Paolo