1 // SPDX-License-Identifier: GPL-2.0-only
2 // Copyright (C) 2015 Broadcom Corporation
3
4 #include <linux/delay.h>
5 #include <linux/io.h>
6 #include <linux/module.h>
7 #include <linux/of.h>
8 #include <linux/phy/phy.h>
9 #include <linux/platform_device.h>
10
11 #define PCIE_CFG_OFFSET 0x00
12 #define PCIE1_PHY_IDDQ_SHIFT 10
13 #define PCIE0_PHY_IDDQ_SHIFT 2
14
15 enum cygnus_pcie_phy_id {
16 CYGNUS_PHY_PCIE0 = 0,
17 CYGNUS_PHY_PCIE1,
18 MAX_NUM_PHYS,
19 };
20
21 struct cygnus_pcie_phy_core;
22
23 /**
24 * struct cygnus_pcie_phy - Cygnus PCIe PHY device
25 * @core: pointer to the Cygnus PCIe PHY core control
26 * @id: internal ID to identify the Cygnus PCIe PHY
27 * @phy: pointer to the kernel PHY device
28 */
29 struct cygnus_pcie_phy {
30 struct cygnus_pcie_phy_core *core;
31 enum cygnus_pcie_phy_id id;
32 struct phy *phy;
33 };
34
35 /**
36 * struct cygnus_pcie_phy_core - Cygnus PCIe PHY core control
37 * @dev: pointer to device
38 * @base: base register
39 * @lock: mutex to protect access to individual PHYs
40 * @phys: pointer to Cygnus PHY device
41 */
42 struct cygnus_pcie_phy_core {
43 struct device *dev;
44 void __iomem *base;
45 struct mutex lock;
46 struct cygnus_pcie_phy phys[MAX_NUM_PHYS];
47 };
48
cygnus_pcie_power_config(struct cygnus_pcie_phy * phy,bool enable)49 static int cygnus_pcie_power_config(struct cygnus_pcie_phy *phy, bool enable)
50 {
51 struct cygnus_pcie_phy_core *core = phy->core;
52 unsigned shift;
53 u32 val;
54
55 mutex_lock(&core->lock);
56
57 switch (phy->id) {
58 case CYGNUS_PHY_PCIE0:
59 shift = PCIE0_PHY_IDDQ_SHIFT;
60 break;
61
62 case CYGNUS_PHY_PCIE1:
63 shift = PCIE1_PHY_IDDQ_SHIFT;
64 break;
65
66 default:
67 mutex_unlock(&core->lock);
68 dev_err(core->dev, "PCIe PHY %d invalid\n", phy->id);
69 return -EINVAL;
70 }
71
72 if (enable) {
73 val = readl(core->base + PCIE_CFG_OFFSET);
74 val &= ~BIT(shift);
75 writel(val, core->base + PCIE_CFG_OFFSET);
76 /*
77 * Wait 50 ms for the PCIe Serdes to stabilize after the analog
78 * front end is brought up
79 */
80 msleep(50);
81 } else {
82 val = readl(core->base + PCIE_CFG_OFFSET);
83 val |= BIT(shift);
84 writel(val, core->base + PCIE_CFG_OFFSET);
85 }
86
87 mutex_unlock(&core->lock);
88 dev_dbg(core->dev, "PCIe PHY %d %s\n", phy->id,
89 enable ? "enabled" : "disabled");
90 return 0;
91 }
92
cygnus_pcie_phy_power_on(struct phy * p)93 static int cygnus_pcie_phy_power_on(struct phy *p)
94 {
95 struct cygnus_pcie_phy *phy = phy_get_drvdata(p);
96
97 return cygnus_pcie_power_config(phy, true);
98 }
99
cygnus_pcie_phy_power_off(struct phy * p)100 static int cygnus_pcie_phy_power_off(struct phy *p)
101 {
102 struct cygnus_pcie_phy *phy = phy_get_drvdata(p);
103
104 return cygnus_pcie_power_config(phy, false);
105 }
106
107 static const struct phy_ops cygnus_pcie_phy_ops = {
108 .power_on = cygnus_pcie_phy_power_on,
109 .power_off = cygnus_pcie_phy_power_off,
110 .owner = THIS_MODULE,
111 };
112
cygnus_pcie_phy_probe(struct platform_device * pdev)113 static int cygnus_pcie_phy_probe(struct platform_device *pdev)
114 {
115 struct device *dev = &pdev->dev;
116 struct device_node *node = dev->of_node, *child;
117 struct cygnus_pcie_phy_core *core;
118 struct phy_provider *provider;
119 unsigned cnt = 0;
120 int ret;
121
122 if (of_get_child_count(node) == 0) {
123 dev_err(dev, "PHY no child node\n");
124 return -ENODEV;
125 }
126
127 core = devm_kzalloc(dev, sizeof(*core), GFP_KERNEL);
128 if (!core)
129 return -ENOMEM;
130
131 core->dev = dev;
132
133 core->base = devm_platform_ioremap_resource(pdev, 0);
134 if (IS_ERR(core->base))
135 return PTR_ERR(core->base);
136
137 mutex_init(&core->lock);
138
139 for_each_available_child_of_node(node, child) {
140 unsigned int id;
141 struct cygnus_pcie_phy *p;
142
143 if (of_property_read_u32(child, "reg", &id)) {
144 dev_err(dev, "missing reg property for %pOFn\n",
145 child);
146 ret = -EINVAL;
147 goto put_child;
148 }
149
150 if (id >= MAX_NUM_PHYS) {
151 dev_err(dev, "invalid PHY id: %u\n", id);
152 ret = -EINVAL;
153 goto put_child;
154 }
155
156 if (core->phys[id].phy) {
157 dev_err(dev, "duplicated PHY id: %u\n", id);
158 ret = -EINVAL;
159 goto put_child;
160 }
161
162 p = &core->phys[id];
163 p->phy = devm_phy_create(dev, child, &cygnus_pcie_phy_ops);
164 if (IS_ERR(p->phy)) {
165 dev_err(dev, "failed to create PHY\n");
166 ret = PTR_ERR(p->phy);
167 goto put_child;
168 }
169
170 p->core = core;
171 p->id = id;
172 phy_set_drvdata(p->phy, p);
173 cnt++;
174 }
175
176 dev_set_drvdata(dev, core);
177
178 provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
179 if (IS_ERR(provider)) {
180 dev_err(dev, "failed to register PHY provider\n");
181 return PTR_ERR(provider);
182 }
183
184 dev_dbg(dev, "registered %u PCIe PHY(s)\n", cnt);
185
186 return 0;
187 put_child:
188 of_node_put(child);
189 return ret;
190 }
191
192 static const struct of_device_id cygnus_pcie_phy_match_table[] = {
193 { .compatible = "brcm,cygnus-pcie-phy" },
194 { /* sentinel */ }
195 };
196 MODULE_DEVICE_TABLE(of, cygnus_pcie_phy_match_table);
197
198 static struct platform_driver cygnus_pcie_phy_driver = {
199 .driver = {
200 .name = "cygnus-pcie-phy",
201 .of_match_table = cygnus_pcie_phy_match_table,
202 },
203 .probe = cygnus_pcie_phy_probe,
204 };
205 module_platform_driver(cygnus_pcie_phy_driver);
206
207 MODULE_AUTHOR("Ray Jui <rjui@broadcom.com>");
208 MODULE_DESCRIPTION("Broadcom Cygnus PCIe PHY driver");
209 MODULE_LICENSE("GPL v2");
210