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