xref: /linux/drivers/phy/phy-econet-pcie.c (revision 3d5e48944e824bddc20d7b874e784f7b279636fe)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Author: Caleb James DeLisle <cjd@cjdns.fr>
4  *	   Ahmed Naseef <naseefkm@gmail.com>
5  */
6 
7 #include <linux/bitfield.h>
8 #include <linux/module.h>
9 #include <linux/of.h>
10 #include <linux/phy/phy.h>
11 #include <linux/platform_device.h>
12 #include <linux/regmap.h>
13 #include <linux/bits.h>
14 #include <linux/delay.h>
15 
16 /* Rx detection timing for EN751221: 16*8 clock cycles  */
17 #define EN751221_RXDET_VAL		16
18 
19 /* Rx detection timing when in power mode 3 */
20 #define EN75_RXDET_P3_REG		0xa28
21 #define EN75_RXDET_P3_MASK		GENMASK(17, 9)
22 
23 /* Rx detection timing when in power mode 2 */
24 #define EN75_RXDET_P2_REG		0xa2c
25 #define EN75_RXDET_P2_MASK		GENMASK(8, 0)
26 
27 /* Rx impedance */
28 #define EN75_RX_IMPEDANCE_REG		0xb2c
29 #define EN75_RX_IMPEDANCE_MASK		GENMASK(13, 12)
30 enum en75_rx_impedance {
31 	EN75_RX_IMPEDANCE_100_OHM	= 0,
32 	EN75_RX_IMPEDANCE_95_OHM	= 1,
33 	EN75_RX_IMPEDANCE_90_OHM	= 2,
34 };
35 
36 /* PLL Invert clock */
37 #define EN75_PLL_PH_INV_REG		0x4a0
38 #define EN75_PLL_PH_INV_MASK		BIT(5)
39 
40 struct en75_phy_op {
41 	u32 reg;
42 	u32 mask;
43 	u32 val;
44 };
45 
46 struct en7528_pcie_phy {
47 	struct regmap *regmap;
48 	const struct en75_phy_op *data;
49 };
50 
51 /* Port 0 PHY: set LCDDS_CLK_PH_INV for PLL operation */
52 static const struct en75_phy_op en7528_phy_gen1[] = {
53 	{
54 		.reg = EN75_PLL_PH_INV_REG,
55 		.mask = EN75_PLL_PH_INV_MASK,
56 		.val = 1,
57 	},
58 	{ /* sentinel */ }
59 };
60 
61 /* EN7528 Port 1 PHY: Rx impedance tuning, target R -5 Ohm */
62 static const struct en75_phy_op en7528_phy_gen2[] = {
63 	{
64 		.reg = EN75_RX_IMPEDANCE_REG,
65 		.mask = EN75_RX_IMPEDANCE_MASK,
66 		.val = EN75_RX_IMPEDANCE_95_OHM,
67 	},
68 	{ /* sentinel */ }
69 };
70 
71 /* EN751221 Port 1 PHY, set RX detect to 16*8 clock cycles */
72 static const struct en75_phy_op en751221_phy_gen2[] = {
73 	{
74 		.reg = EN75_RXDET_P3_REG,
75 		.mask = EN75_RXDET_P3_MASK,
76 		.val = EN751221_RXDET_VAL,
77 	},
78 	{
79 		.reg = EN75_RXDET_P2_REG,
80 		.mask = EN75_RXDET_P2_MASK,
81 		.val = EN751221_RXDET_VAL,
82 	},
83 	{ /* sentinel */ }
84 };
85 
86 static int en75_pcie_phy_init(struct phy *phy)
87 {
88 	struct en7528_pcie_phy *ephy = phy_get_drvdata(phy);
89 	const struct en75_phy_op *data = ephy->data;
90 	int i, ret;
91 	u32 val;
92 
93 	for (i = 0; data[i].mask || data[i].val; i++) {
94 		if (i)
95 			usleep_range(1000, 2000);
96 
97 		val = field_prep(data[i].mask, data[i].val);
98 
99 		ret = regmap_update_bits(ephy->regmap, data[i].reg,
100 					 data[i].mask, val);
101 		if (ret)
102 			return ret;
103 	}
104 
105 	return 0;
106 }
107 
108 static const struct phy_ops en75_pcie_phy_ops = {
109 	.init	= en75_pcie_phy_init,
110 	.owner	= THIS_MODULE,
111 };
112 
113 static int en75_pcie_phy_probe(struct platform_device *pdev)
114 {
115 	struct regmap_config regmap_config = {
116 		.reg_bits = 32,
117 		.val_bits = 32,
118 		.reg_stride = 4,
119 	};
120 	struct device *dev = &pdev->dev;
121 	const struct en75_phy_op *data;
122 	struct phy_provider *provider;
123 	struct en7528_pcie_phy *ephy;
124 	void __iomem *base;
125 	struct phy *phy;
126 	int i;
127 
128 	data = of_device_get_match_data(dev);
129 	if (!data)
130 		return -EINVAL;
131 
132 	ephy = devm_kzalloc(dev, sizeof(*ephy), GFP_KERNEL);
133 	if (!ephy)
134 		return -ENOMEM;
135 
136 	ephy->data = data;
137 
138 	base = devm_platform_ioremap_resource(pdev, 0);
139 	if (IS_ERR(base))
140 		return PTR_ERR(base);
141 
142 	/* Set max_register to highest used register */
143 	for (i = 0; data[i].mask || data[i].val; i++)
144 		if (data[i].reg > regmap_config.max_register)
145 			regmap_config.max_register = data[i].reg;
146 
147 	ephy->regmap = devm_regmap_init_mmio(dev, base, &regmap_config);
148 	if (IS_ERR(ephy->regmap))
149 		return PTR_ERR(ephy->regmap);
150 
151 	phy = devm_phy_create(dev, dev->of_node, &en75_pcie_phy_ops);
152 	if (IS_ERR(phy))
153 		return PTR_ERR(phy);
154 
155 	phy_set_drvdata(phy, ephy);
156 
157 	provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
158 
159 	return PTR_ERR_OR_ZERO(provider);
160 }
161 
162 static const struct of_device_id en75_pcie_phy_ids[] = {
163 	{ .compatible = "econet,en7528-pcie-gen1", .data = en7528_phy_gen1 },
164 	{ .compatible = "econet,en7528-pcie-gen2", .data = en7528_phy_gen2 },
165 	{ .compatible = "econet,en751221-pcie-gen1", .data = en7528_phy_gen1 },
166 	{ .compatible = "econet,en751221-pcie-gen2", .data = en751221_phy_gen2 },
167 	{ /* sentinel */ }
168 };
169 MODULE_DEVICE_TABLE(of, en75_pcie_phy_ids);
170 
171 static struct platform_driver en75_pcie_phy_driver = {
172 	.probe = en75_pcie_phy_probe,
173 	.driver = {
174 		.name = "econet-pcie-phy",
175 		.of_match_table = en75_pcie_phy_ids,
176 	},
177 };
178 module_platform_driver(en75_pcie_phy_driver);
179 
180 MODULE_AUTHOR("Caleb James DeLisle <cjd@cjdns.fr>");
181 MODULE_DESCRIPTION("EcoNet PCIe PHY driver");
182 MODULE_LICENSE("GPL");
183