1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Renesas R-Car Gen3 for USB3.0 PHY driver
4 *
5 * Copyright (C) 2017 Renesas Electronics Corporation
6 */
7
8 #include <linux/clk.h>
9 #include <linux/delay.h>
10 #include <linux/io.h>
11 #include <linux/module.h>
12 #include <linux/of.h>
13 #include <linux/phy/phy.h>
14 #include <linux/platform_device.h>
15 #include <linux/pm_runtime.h>
16
17 #define USB30_CLKSET0 0x034
18 #define USB30_CLKSET1 0x036
19 #define USB30_SSC_SET 0x038
20 #define USB30_PHY_ENABLE 0x060
21 #define USB30_VBUS_EN 0x064
22
23 /* USB30_CLKSET0 */
24 #define CLKSET0_PRIVATE 0x05c0
25 #define CLKSET0_USB30_FSEL_USB_EXTAL 0x0002
26
27 /* USB30_CLKSET1 */
28 #define CLKSET1_USB30_PLL_MULTI_SHIFT 6
29 #define CLKSET1_USB30_PLL_MULTI_USB_EXTAL (0x64 << \
30 CLKSET1_USB30_PLL_MULTI_SHIFT)
31 #define CLKSET1_PHYRESET BIT(4) /* 1: reset */
32 #define CLKSET1_REF_CLKDIV BIT(3) /* 1: USB_EXTAL */
33 #define CLKSET1_PRIVATE_2_1 BIT(1) /* Write B'01 */
34 #define CLKSET1_REF_CLK_SEL BIT(0) /* 1: USB3S0_CLK_P */
35
36 /* USB30_SSC_SET */
37 #define SSC_SET_SSC_EN BIT(12)
38 #define SSC_SET_RANGE_SHIFT 9
39 #define SSC_SET_RANGE_4980 (0x0 << SSC_SET_RANGE_SHIFT)
40 #define SSC_SET_RANGE_4492 (0x1 << SSC_SET_RANGE_SHIFT)
41 #define SSC_SET_RANGE_4003 (0x2 << SSC_SET_RANGE_SHIFT)
42
43 /* USB30_PHY_ENABLE */
44 #define PHY_ENABLE_RESET_EN BIT(4)
45
46 /* USB30_VBUS_EN */
47 #define VBUS_EN_VBUS_EN BIT(1)
48
49 struct rcar_gen3_usb3 {
50 void __iomem *base;
51 struct phy *phy;
52 u32 ssc_range;
53 bool usb3s_clk;
54 bool usb_extal;
55 };
56
write_clkset1_for_usb_extal(struct rcar_gen3_usb3 * r,bool reset)57 static void write_clkset1_for_usb_extal(struct rcar_gen3_usb3 *r, bool reset)
58 {
59 u16 val = CLKSET1_USB30_PLL_MULTI_USB_EXTAL |
60 CLKSET1_REF_CLKDIV | CLKSET1_PRIVATE_2_1;
61
62 if (reset)
63 val |= CLKSET1_PHYRESET;
64
65 writew(val, r->base + USB30_CLKSET1);
66 }
67
rcar_gen3_phy_usb3_enable_ssc(struct rcar_gen3_usb3 * r)68 static void rcar_gen3_phy_usb3_enable_ssc(struct rcar_gen3_usb3 *r)
69 {
70 u16 val = SSC_SET_SSC_EN;
71
72 switch (r->ssc_range) {
73 case 4980:
74 val |= SSC_SET_RANGE_4980;
75 break;
76 case 4492:
77 val |= SSC_SET_RANGE_4492;
78 break;
79 case 4003:
80 val |= SSC_SET_RANGE_4003;
81 break;
82 default:
83 dev_err(&r->phy->dev, "%s: unsupported range (%x)\n", __func__,
84 r->ssc_range);
85 return;
86 }
87
88 writew(val, r->base + USB30_SSC_SET);
89 }
90
rcar_gen3_phy_usb3_select_usb_extal(struct rcar_gen3_usb3 * r)91 static void rcar_gen3_phy_usb3_select_usb_extal(struct rcar_gen3_usb3 *r)
92 {
93 write_clkset1_for_usb_extal(r, false);
94 if (r->ssc_range)
95 rcar_gen3_phy_usb3_enable_ssc(r);
96 writew(CLKSET0_PRIVATE | CLKSET0_USB30_FSEL_USB_EXTAL,
97 r->base + USB30_CLKSET0);
98 writew(PHY_ENABLE_RESET_EN, r->base + USB30_PHY_ENABLE);
99 write_clkset1_for_usb_extal(r, true);
100 usleep_range(10, 20);
101 write_clkset1_for_usb_extal(r, false);
102 }
103
rcar_gen3_phy_usb3_init(struct phy * p)104 static int rcar_gen3_phy_usb3_init(struct phy *p)
105 {
106 struct rcar_gen3_usb3 *r = phy_get_drvdata(p);
107
108 dev_vdbg(&r->phy->dev, "%s: enter (%d, %d, %d)\n", __func__,
109 r->usb3s_clk, r->usb_extal, r->ssc_range);
110
111 if (!r->usb3s_clk && r->usb_extal)
112 rcar_gen3_phy_usb3_select_usb_extal(r);
113
114 /* Enables VBUS detection anyway */
115 writew(VBUS_EN_VBUS_EN, r->base + USB30_VBUS_EN);
116
117 return 0;
118 }
119
120 static const struct phy_ops rcar_gen3_phy_usb3_ops = {
121 .init = rcar_gen3_phy_usb3_init,
122 .owner = THIS_MODULE,
123 };
124
125 static const struct of_device_id rcar_gen3_phy_usb3_match_table[] = {
126 { .compatible = "renesas,rcar-gen3-usb3-phy" },
127 { }
128 };
129 MODULE_DEVICE_TABLE(of, rcar_gen3_phy_usb3_match_table);
130
rcar_gen3_phy_usb3_probe(struct platform_device * pdev)131 static int rcar_gen3_phy_usb3_probe(struct platform_device *pdev)
132 {
133 struct device *dev = &pdev->dev;
134 struct rcar_gen3_usb3 *r;
135 struct phy_provider *provider;
136 int ret = 0;
137 struct clk *clk;
138
139 if (!dev->of_node) {
140 dev_err(dev, "This driver needs device tree\n");
141 return -EINVAL;
142 }
143
144 r = devm_kzalloc(dev, sizeof(*r), GFP_KERNEL);
145 if (!r)
146 return -ENOMEM;
147
148 r->base = devm_platform_ioremap_resource(pdev, 0);
149 if (IS_ERR(r->base))
150 return PTR_ERR(r->base);
151
152 clk = devm_clk_get(dev, "usb3s_clk");
153 if (!IS_ERR(clk) && !clk_prepare_enable(clk)) {
154 r->usb3s_clk = !!clk_get_rate(clk);
155 clk_disable_unprepare(clk);
156 }
157 clk = devm_clk_get(dev, "usb_extal");
158 if (!IS_ERR(clk) && !clk_prepare_enable(clk)) {
159 r->usb_extal = !!clk_get_rate(clk);
160 clk_disable_unprepare(clk);
161 }
162
163 if (!r->usb3s_clk && !r->usb_extal) {
164 dev_err(dev, "This driver needs usb3s_clk and/or usb_extal\n");
165 ret = -EINVAL;
166 goto error;
167 }
168
169 /*
170 * devm_phy_create() will call pm_runtime_enable(&phy->dev);
171 * And then, phy-core will manage runtime pm for this device.
172 */
173 pm_runtime_enable(dev);
174
175 r->phy = devm_phy_create(dev, NULL, &rcar_gen3_phy_usb3_ops);
176 if (IS_ERR(r->phy)) {
177 dev_err(dev, "Failed to create USB3 PHY\n");
178 ret = PTR_ERR(r->phy);
179 goto error;
180 }
181
182 of_property_read_u32(dev->of_node, "renesas,ssc-range", &r->ssc_range);
183
184 platform_set_drvdata(pdev, r);
185 phy_set_drvdata(r->phy, r);
186
187 provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
188 if (IS_ERR(provider)) {
189 dev_err(dev, "Failed to register PHY provider\n");
190 ret = PTR_ERR(provider);
191 goto error;
192 }
193
194 return 0;
195
196 error:
197 pm_runtime_disable(dev);
198
199 return ret;
200 }
201
rcar_gen3_phy_usb3_remove(struct platform_device * pdev)202 static void rcar_gen3_phy_usb3_remove(struct platform_device *pdev)
203 {
204 pm_runtime_disable(&pdev->dev);
205 };
206
207 static struct platform_driver rcar_gen3_phy_usb3_driver = {
208 .driver = {
209 .name = "phy_rcar_gen3_usb3",
210 .of_match_table = rcar_gen3_phy_usb3_match_table,
211 },
212 .probe = rcar_gen3_phy_usb3_probe,
213 .remove_new = rcar_gen3_phy_usb3_remove,
214 };
215 module_platform_driver(rcar_gen3_phy_usb3_driver);
216
217 MODULE_LICENSE("GPL v2");
218 MODULE_DESCRIPTION("Renesas R-Car Gen3 USB 3.0 PHY");
219 MODULE_AUTHOR("Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>");
220