1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * cdns3-ti.c - TI specific Glue layer for Cadence USB Controller
4 *
5 * Copyright (C) 2019 Texas Instruments Incorporated - https://www.ti.com
6 */
7
8 #include <linux/bits.h>
9 #include <linux/clk.h>
10 #include <linux/module.h>
11 #include <linux/kernel.h>
12 #include <linux/interrupt.h>
13 #include <linux/platform_device.h>
14 #include <linux/dma-mapping.h>
15 #include <linux/io.h>
16 #include <linux/of_platform.h>
17 #include <linux/pm_runtime.h>
18
19 /* USB Wrapper register offsets */
20 #define USBSS_PID 0x0
21 #define USBSS_W1 0x4
22 #define USBSS_STATIC_CONFIG 0x8
23 #define USBSS_PHY_TEST 0xc
24 #define USBSS_DEBUG_CTRL 0x10
25 #define USBSS_DEBUG_INFO 0x14
26 #define USBSS_DEBUG_LINK_STATE 0x18
27 #define USBSS_DEVICE_CTRL 0x1c
28
29 /* Wrapper 1 register bits */
30 #define USBSS_W1_PWRUP_RST BIT(0)
31 #define USBSS_W1_OVERCURRENT_SEL BIT(8)
32 #define USBSS_W1_MODESTRAP_SEL BIT(9)
33 #define USBSS_W1_OVERCURRENT BIT(16)
34 #define USBSS_W1_MODESTRAP_MASK GENMASK(18, 17)
35 #define USBSS_W1_MODESTRAP_SHIFT 17
36 #define USBSS_W1_USB2_ONLY BIT(19)
37
38 /* Static config register bits */
39 #define USBSS1_STATIC_PLL_REF_SEL_MASK GENMASK(8, 5)
40 #define USBSS1_STATIC_PLL_REF_SEL_SHIFT 5
41 #define USBSS1_STATIC_LOOPBACK_MODE_MASK GENMASK(4, 3)
42 #define USBSS1_STATIC_LOOPBACK_MODE_SHIFT 3
43 #define USBSS1_STATIC_VBUS_SEL_MASK GENMASK(2, 1)
44 #define USBSS1_STATIC_VBUS_SEL_SHIFT 1
45 #define USBSS1_STATIC_LANE_REVERSE BIT(0)
46
47 /* Modestrap modes */
48 enum modestrap_mode { USBSS_MODESTRAP_MODE_NONE,
49 USBSS_MODESTRAP_MODE_HOST,
50 USBSS_MODESTRAP_MODE_PERIPHERAL};
51
52 struct cdns_ti {
53 struct device *dev;
54 void __iomem *usbss;
55 unsigned usb2_only:1;
56 unsigned vbus_divider:1;
57 struct clk *usb2_refclk;
58 struct clk *lpm_clk;
59 };
60
61 static const int cdns_ti_rate_table[] = { /* in KHZ */
62 9600,
63 10000,
64 12000,
65 19200,
66 20000,
67 24000,
68 25000,
69 26000,
70 38400,
71 40000,
72 58000,
73 50000,
74 52000,
75 };
76
cdns_ti_readl(struct cdns_ti * data,u32 offset)77 static inline u32 cdns_ti_readl(struct cdns_ti *data, u32 offset)
78 {
79 return readl(data->usbss + offset);
80 }
81
cdns_ti_writel(struct cdns_ti * data,u32 offset,u32 value)82 static inline void cdns_ti_writel(struct cdns_ti *data, u32 offset, u32 value)
83 {
84 writel(value, data->usbss + offset);
85 }
86
cdns_ti_probe(struct platform_device * pdev)87 static int cdns_ti_probe(struct platform_device *pdev)
88 {
89 struct device *dev = &pdev->dev;
90 struct device_node *node = pdev->dev.of_node;
91 struct cdns_ti *data;
92 int error;
93 u32 reg;
94 int rate_code, i;
95 unsigned long rate;
96
97 data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
98 if (!data)
99 return -ENOMEM;
100
101 platform_set_drvdata(pdev, data);
102
103 data->dev = dev;
104
105 data->usbss = devm_platform_ioremap_resource(pdev, 0);
106 if (IS_ERR(data->usbss)) {
107 dev_err(dev, "can't map IOMEM resource\n");
108 return PTR_ERR(data->usbss);
109 }
110
111 data->usb2_refclk = devm_clk_get(dev, "ref");
112 if (IS_ERR(data->usb2_refclk)) {
113 dev_err(dev, "can't get usb2_refclk\n");
114 return PTR_ERR(data->usb2_refclk);
115 }
116
117 data->lpm_clk = devm_clk_get(dev, "lpm");
118 if (IS_ERR(data->lpm_clk)) {
119 dev_err(dev, "can't get lpm_clk\n");
120 return PTR_ERR(data->lpm_clk);
121 }
122
123 rate = clk_get_rate(data->usb2_refclk);
124 rate /= 1000; /* To KHz */
125 for (i = 0; i < ARRAY_SIZE(cdns_ti_rate_table); i++) {
126 if (cdns_ti_rate_table[i] == rate)
127 break;
128 }
129
130 if (i == ARRAY_SIZE(cdns_ti_rate_table)) {
131 dev_err(dev, "unsupported usb2_refclk rate: %lu KHz\n", rate);
132 return -EINVAL;
133 }
134
135 rate_code = i;
136
137 pm_runtime_enable(dev);
138 error = pm_runtime_get_sync(dev);
139 if (error < 0) {
140 dev_err(dev, "pm_runtime_get_sync failed: %d\n", error);
141 goto err;
142 }
143
144 /* assert RESET */
145 reg = cdns_ti_readl(data, USBSS_W1);
146 reg &= ~USBSS_W1_PWRUP_RST;
147 cdns_ti_writel(data, USBSS_W1, reg);
148
149 /* set static config */
150 reg = cdns_ti_readl(data, USBSS_STATIC_CONFIG);
151 reg &= ~USBSS1_STATIC_PLL_REF_SEL_MASK;
152 reg |= rate_code << USBSS1_STATIC_PLL_REF_SEL_SHIFT;
153
154 reg &= ~USBSS1_STATIC_VBUS_SEL_MASK;
155 data->vbus_divider = device_property_read_bool(dev, "ti,vbus-divider");
156 if (data->vbus_divider)
157 reg |= 1 << USBSS1_STATIC_VBUS_SEL_SHIFT;
158
159 cdns_ti_writel(data, USBSS_STATIC_CONFIG, reg);
160 reg = cdns_ti_readl(data, USBSS_STATIC_CONFIG);
161
162 /* set USB2_ONLY mode if requested */
163 reg = cdns_ti_readl(data, USBSS_W1);
164 data->usb2_only = device_property_read_bool(dev, "ti,usb2-only");
165 if (data->usb2_only)
166 reg |= USBSS_W1_USB2_ONLY;
167
168 /* set default modestrap */
169 reg |= USBSS_W1_MODESTRAP_SEL;
170 reg &= ~USBSS_W1_MODESTRAP_MASK;
171 reg |= USBSS_MODESTRAP_MODE_NONE << USBSS_W1_MODESTRAP_SHIFT;
172 cdns_ti_writel(data, USBSS_W1, reg);
173
174 /* de-assert RESET */
175 reg |= USBSS_W1_PWRUP_RST;
176 cdns_ti_writel(data, USBSS_W1, reg);
177
178 error = of_platform_populate(node, NULL, NULL, dev);
179 if (error) {
180 dev_err(dev, "failed to create children: %d\n", error);
181 goto err;
182 }
183
184 return 0;
185
186 err:
187 pm_runtime_put_sync(data->dev);
188 pm_runtime_disable(data->dev);
189
190 return error;
191 }
192
cdns_ti_remove_core(struct device * dev,void * c)193 static int cdns_ti_remove_core(struct device *dev, void *c)
194 {
195 struct platform_device *pdev = to_platform_device(dev);
196
197 platform_device_unregister(pdev);
198
199 return 0;
200 }
201
cdns_ti_remove(struct platform_device * pdev)202 static int cdns_ti_remove(struct platform_device *pdev)
203 {
204 struct device *dev = &pdev->dev;
205
206 device_for_each_child(dev, NULL, cdns_ti_remove_core);
207 pm_runtime_put_sync(dev);
208 pm_runtime_disable(dev);
209
210 platform_set_drvdata(pdev, NULL);
211
212 return 0;
213 }
214
215 static const struct of_device_id cdns_ti_of_match[] = {
216 { .compatible = "ti,j721e-usb", },
217 { .compatible = "ti,am64-usb", },
218 {},
219 };
220 MODULE_DEVICE_TABLE(of, cdns_ti_of_match);
221
222 static struct platform_driver cdns_ti_driver = {
223 .probe = cdns_ti_probe,
224 .remove = cdns_ti_remove,
225 .driver = {
226 .name = "cdns3-ti",
227 .of_match_table = cdns_ti_of_match,
228 },
229 };
230
231 module_platform_driver(cdns_ti_driver);
232
233 MODULE_ALIAS("platform:cdns3-ti");
234 MODULE_AUTHOR("Roger Quadros <rogerq@ti.com>");
235 MODULE_LICENSE("GPL v2");
236 MODULE_DESCRIPTION("Cadence USB3 TI Glue Layer");
237