From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

Prepare for adding RZ/T2H SoC support by making the driver configuration
selectable via OF match data. While the RZ/V2H(P) and RZ/T2H use the same
version of the Synopsys DesignWare MAC (version 5.20), the hardware is
synthesized with different options. To accommodate these differences,
introduce a struct holding per-SoC configuration such as clock list,
number of clocks, TX clock rate control, and STMMAC flags, and retrieve
it from the device tree match entry during probe.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
---
 .../stmicro/stmmac/dwmac-renesas-gbeth.c      | 57 +++++++++++++++----
 1 file changed, 47 insertions(+), 10 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-renesas-gbeth.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-renesas-gbeth.c
index df4ca897a60c..022e595a9e1b 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-renesas-gbeth.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-renesas-gbeth.c
@@ -16,12 +16,34 @@
 #include <linux/clk.h>
 #include <linux/device.h>
 #include <linux/module.h>
+#include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/reset.h>
+#include <linux/types.h>
 
 #include "stmmac_platform.h"
 
+/**
+ * struct renesas_gbeth_of_data - OF data for Renesas GBETH
+ *
+ * @clks: Array of clock names
+ * @num_clks: Number of clocks
+ * @stmmac_flags: Flags for the stmmac driver
+ * @handle_reset: Flag to indicate if reset control is
+ *                handled by the glue driver or core driver.
+ * @set_clk_tx_rate: Flag to indicate if Tx clock is fixed or
+ *                   set_clk_tx_rate is needed.
+ */
+struct renesas_gbeth_of_data {
+	const char * const *clks;
+	u8 num_clks;
+	u32 stmmac_flags;
+	bool handle_reset;
+	bool set_clk_tx_rate;
+};
+
 struct renesas_gbeth {
+	const struct renesas_gbeth_of_data *of_data;
 	struct plat_stmmacenet_data *plat_dat;
 	struct reset_control *rstc;
 	struct device *dev;
@@ -70,6 +92,7 @@ static void renesas_gbeth_exit(struct platform_device *pdev, void *priv)
 
 static int renesas_gbeth_probe(struct platform_device *pdev)
 {
+	const struct renesas_gbeth_of_data *of_data;
 	struct plat_stmmacenet_data *plat_dat;
 	struct stmmac_resources stmmac_res;
 	struct device *dev = &pdev->dev;
@@ -91,14 +114,17 @@ static int renesas_gbeth_probe(struct platform_device *pdev)
 	if (!gbeth)
 		return -ENOMEM;
 
-	plat_dat->num_clks = ARRAY_SIZE(renesas_gbeth_clks);
+	of_data = of_device_get_match_data(&pdev->dev);
+	gbeth->of_data = of_data;
+
+	plat_dat->num_clks = of_data->num_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];
+		plat_dat->clks[i].id = of_data->clks[i];
 
 	err = devm_clk_bulk_get(dev, plat_dat->num_clks, plat_dat->clks);
 	if (err < 0)
@@ -109,25 +135,36 @@ static int renesas_gbeth_probe(struct platform_device *pdev)
 		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);
+	if (of_data->handle_reset) {
+		gbeth->rstc = devm_reset_control_get_exclusive(dev, NULL);
+		if (IS_ERR(gbeth->rstc))
+			return PTR_ERR(gbeth->rstc);
+	}
 
 	gbeth->dev = dev;
 	gbeth->plat_dat = plat_dat;
 	plat_dat->bsp_priv = gbeth;
-	plat_dat->set_clk_tx_rate = stmmac_set_clk_tx_rate;
+	if (of_data->set_clk_tx_rate)
+		plat_dat->set_clk_tx_rate = stmmac_set_clk_tx_rate;
 	plat_dat->init = renesas_gbeth_init;
 	plat_dat->exit = renesas_gbeth_exit;
-	plat_dat->flags |= STMMAC_FLAG_HWTSTAMP_CORRECT_LATENCY |
-			   STMMAC_FLAG_EN_TX_LPI_CLK_PHY_CAP |
-			   STMMAC_FLAG_SPH_DISABLE;
+	plat_dat->flags |= gbeth->of_data->stmmac_flags;
 
 	return devm_stmmac_pltfr_probe(pdev, plat_dat, &stmmac_res);
 }
 
+static const struct renesas_gbeth_of_data renesas_gbeth_of_data = {
+	.clks = renesas_gbeth_clks,
+	.num_clks = ARRAY_SIZE(renesas_gbeth_clks),
+	.handle_reset = true,
+	.set_clk_tx_rate = true,
+	.stmmac_flags = STMMAC_FLAG_HWTSTAMP_CORRECT_LATENCY |
+			STMMAC_FLAG_EN_TX_LPI_CLK_PHY_CAP |
+			STMMAC_FLAG_SPH_DISABLE,
+};
+
 static const struct of_device_id renesas_gbeth_match[] = {
-	{ .compatible = "renesas,rzv2h-gbeth", },
+	{ .compatible = "renesas,rzv2h-gbeth", .data = &renesas_gbeth_of_data },
 	{ /* Sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, renesas_gbeth_match);
-- 
2.51.0