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/regmap.h>
14 #include <linux/reset.h>
15 #include <linux/reset-controller.h>
16 #include <linux/mfd/syscon.h>
17
18 #define RESET 0x000
19 #define VBENCTL 0x03c
20
21 #define RESET_SEL_PLLRESET BIT(12)
22 #define RESET_PLLRESET BIT(8)
23
24 #define RESET_SEL_P2RESET BIT(5)
25 #define RESET_SEL_P1RESET BIT(4)
26 #define RESET_PHYRST_2 BIT(1)
27 #define RESET_PHYRST_1 BIT(0)
28
29 #define PHY_RESET_PORT2 (RESET_SEL_P2RESET | RESET_PHYRST_2)
30 #define PHY_RESET_PORT1 (RESET_SEL_P1RESET | RESET_PHYRST_1)
31
32 #define NUM_PORTS 2
33
34 struct rzg2l_usbphy_ctrl_priv {
35 struct reset_controller_dev rcdev;
36 struct reset_control *rstc;
37 void __iomem *base;
38 struct platform_device *vdev;
39
40 spinlock_t lock;
41 };
42
43 #define rcdev_to_priv(x) container_of(x, struct rzg2l_usbphy_ctrl_priv, rcdev)
44
rzg2l_usbphy_ctrl_assert(struct reset_controller_dev * rcdev,unsigned long id)45 static int rzg2l_usbphy_ctrl_assert(struct reset_controller_dev *rcdev,
46 unsigned long id)
47 {
48 struct rzg2l_usbphy_ctrl_priv *priv = rcdev_to_priv(rcdev);
49 u32 port_mask = PHY_RESET_PORT1 | PHY_RESET_PORT2;
50 void __iomem *base = priv->base;
51 unsigned long flags;
52 u32 val;
53
54 spin_lock_irqsave(&priv->lock, flags);
55 val = readl(base + RESET);
56 val |= id ? PHY_RESET_PORT2 : PHY_RESET_PORT1;
57 if (port_mask == (val & port_mask))
58 val |= RESET_PLLRESET;
59 writel(val, base + RESET);
60 spin_unlock_irqrestore(&priv->lock, flags);
61
62 return 0;
63 }
64
rzg2l_usbphy_ctrl_deassert(struct reset_controller_dev * rcdev,unsigned long id)65 static int rzg2l_usbphy_ctrl_deassert(struct reset_controller_dev *rcdev,
66 unsigned long id)
67 {
68 struct rzg2l_usbphy_ctrl_priv *priv = rcdev_to_priv(rcdev);
69 void __iomem *base = priv->base;
70 unsigned long flags;
71 u32 val;
72
73 spin_lock_irqsave(&priv->lock, flags);
74 val = readl(base + RESET);
75
76 val |= RESET_SEL_PLLRESET;
77 val &= ~(RESET_PLLRESET | (id ? PHY_RESET_PORT2 : PHY_RESET_PORT1));
78 writel(val, base + RESET);
79 spin_unlock_irqrestore(&priv->lock, flags);
80
81 return 0;
82 }
83
rzg2l_usbphy_ctrl_status(struct reset_controller_dev * rcdev,unsigned long id)84 static int rzg2l_usbphy_ctrl_status(struct reset_controller_dev *rcdev,
85 unsigned long id)
86 {
87 struct rzg2l_usbphy_ctrl_priv *priv = rcdev_to_priv(rcdev);
88 u32 port_mask;
89
90 port_mask = id ? PHY_RESET_PORT2 : PHY_RESET_PORT1;
91
92 return !!(readl(priv->base + RESET) & port_mask);
93 }
94
95 #define RZG2L_USBPHY_CTRL_PWRRDY 1
96
97 static const struct of_device_id rzg2l_usbphy_ctrl_match_table[] = {
98 { .compatible = "renesas,rzg2l-usbphy-ctrl" },
99 {
100 .compatible = "renesas,r9a08g045-usbphy-ctrl",
101 .data = (void *)RZG2L_USBPHY_CTRL_PWRRDY
102 },
103 { /* Sentinel */ }
104 };
105 MODULE_DEVICE_TABLE(of, rzg2l_usbphy_ctrl_match_table);
106
107 static const struct reset_control_ops rzg2l_usbphy_ctrl_reset_ops = {
108 .assert = rzg2l_usbphy_ctrl_assert,
109 .deassert = rzg2l_usbphy_ctrl_deassert,
110 .status = rzg2l_usbphy_ctrl_status,
111 };
112
113 static const struct regmap_config rzg2l_usb_regconf = {
114 .reg_bits = 32,
115 .val_bits = 32,
116 .reg_stride = 4,
117 .max_register = 1,
118 };
119
rzg2l_usbphy_ctrl_set_pwrrdy(struct regmap_field * pwrrdy,bool power_on)120 static void rzg2l_usbphy_ctrl_set_pwrrdy(struct regmap_field *pwrrdy,
121 bool power_on)
122 {
123 u32 val = power_on ? 0 : 1;
124
125 /* The initialization path guarantees that the mask is 1 bit long. */
126 regmap_field_update_bits(pwrrdy, 1, val);
127 }
128
rzg2l_usbphy_ctrl_pwrrdy_off(void * data)129 static void rzg2l_usbphy_ctrl_pwrrdy_off(void *data)
130 {
131 rzg2l_usbphy_ctrl_set_pwrrdy(data, false);
132 }
133
rzg2l_usbphy_ctrl_pwrrdy_init(struct device * dev)134 static int rzg2l_usbphy_ctrl_pwrrdy_init(struct device *dev)
135 {
136 struct regmap_field *pwrrdy;
137 struct reg_field field;
138 struct regmap *regmap;
139 const int *data;
140 u32 args[2];
141
142 data = device_get_match_data(dev);
143 if ((uintptr_t)data != RZG2L_USBPHY_CTRL_PWRRDY)
144 return 0;
145
146 regmap = syscon_regmap_lookup_by_phandle_args(dev->of_node,
147 "renesas,sysc-pwrrdy",
148 ARRAY_SIZE(args), args);
149 if (IS_ERR(regmap))
150 return PTR_ERR(regmap);
151
152 /* Don't allow more than one bit in mask. */
153 if (hweight32(args[1]) != 1)
154 return -EINVAL;
155
156 field.reg = args[0];
157 field.lsb = __ffs(args[1]);
158 field.msb = __fls(args[1]);
159
160 pwrrdy = devm_regmap_field_alloc(dev, regmap, field);
161 if (IS_ERR(pwrrdy))
162 return PTR_ERR(pwrrdy);
163
164 rzg2l_usbphy_ctrl_set_pwrrdy(pwrrdy, true);
165
166 return devm_add_action_or_reset(dev, rzg2l_usbphy_ctrl_pwrrdy_off, pwrrdy);
167 }
168
rzg2l_usbphy_ctrl_probe(struct platform_device * pdev)169 static int rzg2l_usbphy_ctrl_probe(struct platform_device *pdev)
170 {
171 struct device *dev = &pdev->dev;
172 struct rzg2l_usbphy_ctrl_priv *priv;
173 struct platform_device *vdev;
174 struct regmap *regmap;
175 unsigned long flags;
176 int error;
177 u32 val;
178
179 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
180 if (!priv)
181 return -ENOMEM;
182
183 priv->base = devm_platform_ioremap_resource(pdev, 0);
184 if (IS_ERR(priv->base))
185 return PTR_ERR(priv->base);
186
187 regmap = devm_regmap_init_mmio(dev, priv->base + VBENCTL, &rzg2l_usb_regconf);
188 if (IS_ERR(regmap))
189 return PTR_ERR(regmap);
190
191 error = rzg2l_usbphy_ctrl_pwrrdy_init(dev);
192 if (error)
193 return error;
194
195 priv->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
196 if (IS_ERR(priv->rstc))
197 return dev_err_probe(dev, PTR_ERR(priv->rstc),
198 "failed to get reset\n");
199
200 error = reset_control_deassert(priv->rstc);
201 if (error)
202 return error;
203
204 spin_lock_init(&priv->lock);
205 dev_set_drvdata(dev, priv);
206
207 pm_runtime_enable(&pdev->dev);
208 error = pm_runtime_resume_and_get(&pdev->dev);
209 if (error < 0) {
210 dev_err_probe(&pdev->dev, error, "pm_runtime_resume_and_get failed");
211 goto err_pm_disable_reset_deassert;
212 }
213
214 /* put pll and phy into reset state */
215 spin_lock_irqsave(&priv->lock, flags);
216 val = readl(priv->base + RESET);
217 val |= RESET_SEL_PLLRESET | RESET_PLLRESET | PHY_RESET_PORT2 | PHY_RESET_PORT1;
218 writel(val, priv->base + RESET);
219 spin_unlock_irqrestore(&priv->lock, flags);
220
221 priv->rcdev.ops = &rzg2l_usbphy_ctrl_reset_ops;
222 priv->rcdev.of_reset_n_cells = 1;
223 priv->rcdev.nr_resets = NUM_PORTS;
224 priv->rcdev.of_node = dev->of_node;
225 priv->rcdev.dev = dev;
226
227 error = devm_reset_controller_register(dev, &priv->rcdev);
228 if (error)
229 goto err_pm_runtime_put;
230
231 vdev = platform_device_alloc("rzg2l-usb-vbus-regulator", pdev->id);
232 if (!vdev) {
233 error = -ENOMEM;
234 goto err_pm_runtime_put;
235 }
236 vdev->dev.parent = dev;
237 priv->vdev = vdev;
238
239 device_set_of_node_from_dev(&vdev->dev, dev);
240 error = platform_device_add(vdev);
241 if (error)
242 goto err_device_put;
243
244 return 0;
245
246 err_device_put:
247 platform_device_put(vdev);
248 err_pm_runtime_put:
249 pm_runtime_put(&pdev->dev);
250 err_pm_disable_reset_deassert:
251 pm_runtime_disable(&pdev->dev);
252 reset_control_assert(priv->rstc);
253 return error;
254 }
255
rzg2l_usbphy_ctrl_remove(struct platform_device * pdev)256 static void rzg2l_usbphy_ctrl_remove(struct platform_device *pdev)
257 {
258 struct rzg2l_usbphy_ctrl_priv *priv = dev_get_drvdata(&pdev->dev);
259
260 platform_device_unregister(priv->vdev);
261 pm_runtime_put(&pdev->dev);
262 pm_runtime_disable(&pdev->dev);
263 reset_control_assert(priv->rstc);
264 }
265
266 static struct platform_driver rzg2l_usbphy_ctrl_driver = {
267 .driver = {
268 .name = "rzg2l_usbphy_ctrl",
269 .of_match_table = rzg2l_usbphy_ctrl_match_table,
270 },
271 .probe = rzg2l_usbphy_ctrl_probe,
272 .remove = rzg2l_usbphy_ctrl_remove,
273 };
274 module_platform_driver(rzg2l_usbphy_ctrl_driver);
275
276 MODULE_LICENSE("GPL v2");
277 MODULE_DESCRIPTION("Renesas RZ/G2L USBPHY Control");
278 MODULE_AUTHOR("biju.das.jz@bp.renesas.com>");
279