1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Nuvoton DWMAC specific glue layer
4 *
5 * Copyright (C) 2025 Nuvoton Technology Corp.
6 *
7 * Author: Joey Lu <a0987203069@gmail.com>
8 */
9
10 #include <linux/mfd/syscon.h>
11 #include <linux/mod_devicetable.h>
12 #include <linux/of.h>
13 #include <linux/of_net.h>
14 #include <linux/platform_device.h>
15 #include <linux/regmap.h>
16 #include <linux/stmmac.h>
17
18 #include "stmmac_platform.h"
19
20 #define NVT_REG_SYS_GMAC0MISCR 0x108
21 #define NVT_REG_SYS_GMAC1MISCR 0x10C
22
23 #define NVT_MISCR_RMII BIT(0)
24
25 /* Two thousand picoseconds are evenly mapped to a 4-bit field,
26 * resulting in each step being 2000/15 picoseconds.
27 */
28 #define NVT_PATH_DELAY_STEP 134
29 #define NVT_TX_DELAY_MASK GENMASK(19, 16)
30 #define NVT_RX_DELAY_MASK GENMASK(23, 20)
31
32 struct nvt_priv_data {
33 struct device *dev;
34 struct regmap *regmap;
35 u32 macid;
36 };
37
nvt_gmac_get_delay(struct device * dev,const char * property)38 static int nvt_gmac_get_delay(struct device *dev, const char *property)
39 {
40 u32 arg;
41
42 if (of_property_read_u32(dev->of_node, property, &arg))
43 return 0;
44
45 if (arg > 2000)
46 return -EINVAL;
47
48 if (arg == 2000)
49 return 15;
50
51 return arg / NVT_PATH_DELAY_STEP;
52 }
53
nvt_set_phy_intf_sel(void * bsp_priv,u8 phy_intf_sel)54 static int nvt_set_phy_intf_sel(void *bsp_priv, u8 phy_intf_sel)
55 {
56 struct nvt_priv_data *priv = bsp_priv;
57 u32 reg, val;
58 int ret;
59
60 if (phy_intf_sel == PHY_INTF_SEL_RGMII) {
61 ret = nvt_gmac_get_delay(priv->dev, "rx-internal-delay-ps");
62 if (ret < 0)
63 return ret;
64 val = FIELD_PREP(NVT_RX_DELAY_MASK, ret);
65
66 ret = nvt_gmac_get_delay(priv->dev, "tx-internal-delay-ps");
67 if (ret < 0)
68 return ret;
69 val |= FIELD_PREP(NVT_TX_DELAY_MASK, ret);
70 } else if (phy_intf_sel == PHY_INTF_SEL_RMII) {
71 val = NVT_MISCR_RMII;
72 } else {
73 return -EINVAL;
74 }
75
76 reg = (priv->macid == 0) ? NVT_REG_SYS_GMAC0MISCR : NVT_REG_SYS_GMAC1MISCR;
77 regmap_update_bits(priv->regmap, reg,
78 NVT_RX_DELAY_MASK | NVT_TX_DELAY_MASK | NVT_MISCR_RMII, val);
79
80 return 0;
81 }
82
nvt_gmac_probe(struct platform_device * pdev)83 static int nvt_gmac_probe(struct platform_device *pdev)
84 {
85 struct plat_stmmacenet_data *plat_dat;
86 struct stmmac_resources stmmac_res;
87 struct device *dev = &pdev->dev;
88 struct nvt_priv_data *priv;
89 int ret;
90
91 ret = stmmac_get_platform_resources(pdev, &stmmac_res);
92 if (ret)
93 return dev_err_probe(dev, ret, "Failed to get platform resources\n");
94
95 plat_dat = devm_stmmac_probe_config_dt(pdev, stmmac_res.mac);
96 if (IS_ERR(plat_dat))
97 return dev_err_probe(dev, PTR_ERR(plat_dat), "Failed to get platform data\n");
98
99 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
100 if (!priv)
101 return dev_err_probe(dev, -ENOMEM, "Failed to allocate private data\n");
102
103 priv->dev = dev;
104
105 priv->regmap = syscon_regmap_lookup_by_phandle_args(dev->of_node, "nuvoton,sys",
106 1, &priv->macid);
107 if (IS_ERR(priv->regmap))
108 return dev_err_probe(dev, PTR_ERR(priv->regmap), "Failed to get sys register\n");
109
110 if (priv->macid > 1)
111 return dev_err_probe(dev, -EINVAL, "Invalid sys arguments\n");
112
113 plat_dat->bsp_priv = priv;
114 plat_dat->set_phy_intf_sel = nvt_set_phy_intf_sel;
115
116 return stmmac_pltfr_probe(pdev, plat_dat, &stmmac_res);
117 }
118
119 static const struct of_device_id nvt_dwmac_match[] = {
120 { .compatible = "nuvoton,ma35d1-dwmac"},
121 { }
122 };
123 MODULE_DEVICE_TABLE(of, nvt_dwmac_match);
124
125 static struct platform_driver nvt_dwmac_driver = {
126 .probe = nvt_gmac_probe,
127 .remove = stmmac_pltfr_remove,
128 .driver = {
129 .name = "nuvoton-dwmac",
130 .pm = &stmmac_pltfr_pm_ops,
131 .of_match_table = nvt_dwmac_match,
132 },
133 };
134 module_platform_driver(nvt_dwmac_driver);
135
136 MODULE_AUTHOR("Joey Lu <a0987203069@gmail.com>");
137 MODULE_DESCRIPTION("Nuvoton DWMAC specific glue layer");
138 MODULE_LICENSE("GPL");
139