1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Renesas RZ/G2L USBPHY control driver
4 *
5 * Copyright (C) 2021 Renesas Electronics Corporation
6 */
7
8 #include <linux/io.h>
9 #include <linux/module.h>
10 #include <linux/of.h>
11 #include <linux/platform_device.h>
12 #include <linux/pm_runtime.h>
13 #include <linux/reset.h>
14 #include <linux/reset-controller.h>
15
16 #define RESET 0x000
17
18 #define RESET_SEL_PLLRESET BIT(12)
19 #define RESET_PLLRESET BIT(8)
20
21 #define RESET_SEL_P2RESET BIT(5)
22 #define RESET_SEL_P1RESET BIT(4)
23 #define RESET_PHYRST_2 BIT(1)
24 #define RESET_PHYRST_1 BIT(0)
25
26 #define PHY_RESET_PORT2 (RESET_SEL_P2RESET | RESET_PHYRST_2)
27 #define PHY_RESET_PORT1 (RESET_SEL_P1RESET | RESET_PHYRST_1)
28
29 #define NUM_PORTS 2
30
31 struct rzg2l_usbphy_ctrl_priv {
32 struct reset_controller_dev rcdev;
33 struct reset_control *rstc;
34 void __iomem *base;
35
36 spinlock_t lock;
37 };
38
39 #define rcdev_to_priv(x) container_of(x, struct rzg2l_usbphy_ctrl_priv, rcdev)
40
rzg2l_usbphy_ctrl_assert(struct reset_controller_dev * rcdev,unsigned long id)41 static int rzg2l_usbphy_ctrl_assert(struct reset_controller_dev *rcdev,
42 unsigned long id)
43 {
44 struct rzg2l_usbphy_ctrl_priv *priv = rcdev_to_priv(rcdev);
45 u32 port_mask = PHY_RESET_PORT1 | PHY_RESET_PORT2;
46 void __iomem *base = priv->base;
47 unsigned long flags;
48 u32 val;
49
50 spin_lock_irqsave(&priv->lock, flags);
51 val = readl(base + RESET);
52 val |= id ? PHY_RESET_PORT2 : PHY_RESET_PORT1;
53 if (port_mask == (val & port_mask))
54 val |= RESET_PLLRESET;
55 writel(val, base + RESET);
56 spin_unlock_irqrestore(&priv->lock, flags);
57
58 return 0;
59 }
60
rzg2l_usbphy_ctrl_deassert(struct reset_controller_dev * rcdev,unsigned long id)61 static int rzg2l_usbphy_ctrl_deassert(struct reset_controller_dev *rcdev,
62 unsigned long id)
63 {
64 struct rzg2l_usbphy_ctrl_priv *priv = rcdev_to_priv(rcdev);
65 void __iomem *base = priv->base;
66 unsigned long flags;
67 u32 val;
68
69 spin_lock_irqsave(&priv->lock, flags);
70 val = readl(base + RESET);
71
72 val |= RESET_SEL_PLLRESET;
73 val &= ~(RESET_PLLRESET | (id ? PHY_RESET_PORT2 : PHY_RESET_PORT1));
74 writel(val, base + RESET);
75 spin_unlock_irqrestore(&priv->lock, flags);
76
77 return 0;
78 }
79
rzg2l_usbphy_ctrl_status(struct reset_controller_dev * rcdev,unsigned long id)80 static int rzg2l_usbphy_ctrl_status(struct reset_controller_dev *rcdev,
81 unsigned long id)
82 {
83 struct rzg2l_usbphy_ctrl_priv *priv = rcdev_to_priv(rcdev);
84 u32 port_mask;
85
86 port_mask = id ? PHY_RESET_PORT2 : PHY_RESET_PORT1;
87
88 return !!(readl(priv->base + RESET) & port_mask);
89 }
90
91 static const struct of_device_id rzg2l_usbphy_ctrl_match_table[] = {
92 { .compatible = "renesas,rzg2l-usbphy-ctrl" },
93 { /* Sentinel */ }
94 };
95 MODULE_DEVICE_TABLE(of, rzg2l_usbphy_ctrl_match_table);
96
97 static const struct reset_control_ops rzg2l_usbphy_ctrl_reset_ops = {
98 .assert = rzg2l_usbphy_ctrl_assert,
99 .deassert = rzg2l_usbphy_ctrl_deassert,
100 .status = rzg2l_usbphy_ctrl_status,
101 };
102
rzg2l_usbphy_ctrl_probe(struct platform_device * pdev)103 static int rzg2l_usbphy_ctrl_probe(struct platform_device *pdev)
104 {
105 struct device *dev = &pdev->dev;
106 struct rzg2l_usbphy_ctrl_priv *priv;
107 unsigned long flags;
108 int error;
109 u32 val;
110
111 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
112 if (!priv)
113 return -ENOMEM;
114
115 priv->base = devm_platform_ioremap_resource(pdev, 0);
116 if (IS_ERR(priv->base))
117 return PTR_ERR(priv->base);
118
119 priv->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
120 if (IS_ERR(priv->rstc))
121 return dev_err_probe(dev, PTR_ERR(priv->rstc),
122 "failed to get reset\n");
123
124 error = reset_control_deassert(priv->rstc);
125 if (error)
126 return error;
127
128 priv->rcdev.ops = &rzg2l_usbphy_ctrl_reset_ops;
129 priv->rcdev.of_reset_n_cells = 1;
130 priv->rcdev.nr_resets = NUM_PORTS;
131 priv->rcdev.of_node = dev->of_node;
132 priv->rcdev.dev = dev;
133
134 error = devm_reset_controller_register(dev, &priv->rcdev);
135 if (error)
136 return error;
137
138 spin_lock_init(&priv->lock);
139 dev_set_drvdata(dev, priv);
140
141 pm_runtime_enable(&pdev->dev);
142 error = pm_runtime_resume_and_get(&pdev->dev);
143 if (error < 0) {
144 pm_runtime_disable(&pdev->dev);
145 reset_control_assert(priv->rstc);
146 return dev_err_probe(&pdev->dev, error, "pm_runtime_resume_and_get failed");
147 }
148
149 /* put pll and phy into reset state */
150 spin_lock_irqsave(&priv->lock, flags);
151 val = readl(priv->base + RESET);
152 val |= RESET_SEL_PLLRESET | RESET_PLLRESET | PHY_RESET_PORT2 | PHY_RESET_PORT1;
153 writel(val, priv->base + RESET);
154 spin_unlock_irqrestore(&priv->lock, flags);
155
156 return 0;
157 }
158
rzg2l_usbphy_ctrl_remove(struct platform_device * pdev)159 static int rzg2l_usbphy_ctrl_remove(struct platform_device *pdev)
160 {
161 struct rzg2l_usbphy_ctrl_priv *priv = dev_get_drvdata(&pdev->dev);
162
163 pm_runtime_put(&pdev->dev);
164 pm_runtime_disable(&pdev->dev);
165 reset_control_assert(priv->rstc);
166
167 return 0;
168 }
169
170 static struct platform_driver rzg2l_usbphy_ctrl_driver = {
171 .driver = {
172 .name = "rzg2l_usbphy_ctrl",
173 .of_match_table = rzg2l_usbphy_ctrl_match_table,
174 },
175 .probe = rzg2l_usbphy_ctrl_probe,
176 .remove = rzg2l_usbphy_ctrl_remove,
177 };
178 module_platform_driver(rzg2l_usbphy_ctrl_driver);
179
180 MODULE_LICENSE("GPL v2");
181 MODULE_DESCRIPTION("Renesas RZ/G2L USBPHY Control");
182 MODULE_AUTHOR("biju.das.jz@bp.renesas.com>");
183