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 #include "core.h"
20 
21 /* USB Wrapper register offsets */
22 #define USBSS_PID		0x0
23 #define	USBSS_W1		0x4
24 #define USBSS_STATIC_CONFIG	0x8
25 #define USBSS_PHY_TEST		0xc
26 #define	USBSS_DEBUG_CTRL	0x10
27 #define	USBSS_DEBUG_INFO	0x14
28 #define	USBSS_DEBUG_LINK_STATE	0x18
29 #define	USBSS_DEVICE_CTRL	0x1c
30 
31 /* Wrapper 1 register bits */
32 #define USBSS_W1_PWRUP_RST		BIT(0)
33 #define USBSS_W1_OVERCURRENT_SEL	BIT(8)
34 #define USBSS_W1_MODESTRAP_SEL		BIT(9)
35 #define USBSS_W1_OVERCURRENT		BIT(16)
36 #define USBSS_W1_MODESTRAP_MASK		GENMASK(18, 17)
37 #define USBSS_W1_MODESTRAP_SHIFT	17
38 #define USBSS_W1_USB2_ONLY		BIT(19)
39 
40 /* Static config register bits */
41 #define USBSS1_STATIC_PLL_REF_SEL_MASK	GENMASK(8, 5)
42 #define USBSS1_STATIC_PLL_REF_SEL_SHIFT	5
43 #define USBSS1_STATIC_LOOPBACK_MODE_MASK	GENMASK(4, 3)
44 #define USBSS1_STATIC_LOOPBACK_MODE_SHIFT	3
45 #define USBSS1_STATIC_VBUS_SEL_MASK	GENMASK(2, 1)
46 #define USBSS1_STATIC_VBUS_SEL_SHIFT	1
47 #define USBSS1_STATIC_LANE_REVERSE	BIT(0)
48 
49 /* Modestrap modes */
50 enum modestrap_mode { USBSS_MODESTRAP_MODE_NONE,
51 		      USBSS_MODESTRAP_MODE_HOST,
52 		      USBSS_MODESTRAP_MODE_PERIPHERAL};
53 
54 struct cdns_ti {
55 	struct device *dev;
56 	void __iomem *usbss;
57 	unsigned usb2_only:1;
58 	unsigned vbus_divider:1;
59 	struct clk *usb2_refclk;
60 	struct clk *lpm_clk;
61 	int usb2_refclk_rate_code;
62 };
63 
64 static const int cdns_ti_rate_table[] = {	/* in KHZ */
65 	9600,
66 	10000,
67 	12000,
68 	19200,
69 	20000,
70 	24000,
71 	25000,
72 	26000,
73 	38400,
74 	40000,
75 	58000,
76 	50000,
77 	52000,
78 };
79 
80 static inline u32 cdns_ti_readl(struct cdns_ti *data, u32 offset)
81 {
82 	return readl(data->usbss + offset);
83 }
84 
85 static inline void cdns_ti_writel(struct cdns_ti *data, u32 offset, u32 value)
86 {
87 	writel(value, data->usbss + offset);
88 }
89 
90 static struct cdns3_platform_data cdns_ti_pdata = {
91 	.quirks = CDNS3_DRD_SUSPEND_RESIDENCY_ENABLE,   /* Errata i2409 */
92 };
93 
94 static const struct of_dev_auxdata cdns_ti_auxdata[] = {
95 	{
96 		.compatible = "cdns,usb3",
97 		.platform_data = &cdns_ti_pdata,
98 	},
99 	{},
100 };
101 
102 static void cdns_ti_reset_and_init_hw(struct cdns_ti *data)
103 {
104 	u32 reg;
105 
106 	/* assert RESET */
107 	reg = cdns_ti_readl(data, USBSS_W1);
108 	reg &= ~USBSS_W1_PWRUP_RST;
109 	cdns_ti_writel(data, USBSS_W1, reg);
110 
111 	/* set static config */
112 	reg = cdns_ti_readl(data, USBSS_STATIC_CONFIG);
113 	reg &= ~USBSS1_STATIC_PLL_REF_SEL_MASK;
114 	reg |= data->usb2_refclk_rate_code << USBSS1_STATIC_PLL_REF_SEL_SHIFT;
115 
116 	reg &= ~USBSS1_STATIC_VBUS_SEL_MASK;
117 	if (data->vbus_divider)
118 		reg |= 1 << USBSS1_STATIC_VBUS_SEL_SHIFT;
119 
120 	cdns_ti_writel(data, USBSS_STATIC_CONFIG, reg);
121 	reg = cdns_ti_readl(data, USBSS_STATIC_CONFIG);
122 
123 	/* set USB2_ONLY mode if requested */
124 	reg = cdns_ti_readl(data, USBSS_W1);
125 	if (data->usb2_only)
126 		reg |= USBSS_W1_USB2_ONLY;
127 
128 	/* set default modestrap */
129 	reg |= USBSS_W1_MODESTRAP_SEL;
130 	reg &= ~USBSS_W1_MODESTRAP_MASK;
131 	reg |= USBSS_MODESTRAP_MODE_NONE << USBSS_W1_MODESTRAP_SHIFT;
132 	cdns_ti_writel(data, USBSS_W1, reg);
133 
134 	/* de-assert RESET */
135 	reg |= USBSS_W1_PWRUP_RST;
136 	cdns_ti_writel(data, USBSS_W1, reg);
137 }
138 
139 static int cdns_ti_probe(struct platform_device *pdev)
140 {
141 	struct device *dev = &pdev->dev;
142 	struct device_node *node = pdev->dev.of_node;
143 	struct cdns_ti *data;
144 	unsigned long rate;
145 	int error, i;
146 
147 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
148 	if (!data)
149 		return -ENOMEM;
150 
151 	platform_set_drvdata(pdev, data);
152 
153 	data->dev = dev;
154 
155 	data->usbss = devm_platform_ioremap_resource(pdev, 0);
156 	if (IS_ERR(data->usbss)) {
157 		dev_err(dev, "can't map IOMEM resource\n");
158 		return PTR_ERR(data->usbss);
159 	}
160 
161 	data->usb2_refclk = devm_clk_get(dev, "ref");
162 	if (IS_ERR(data->usb2_refclk)) {
163 		dev_err(dev, "can't get usb2_refclk\n");
164 		return PTR_ERR(data->usb2_refclk);
165 	}
166 
167 	data->lpm_clk = devm_clk_get(dev, "lpm");
168 	if (IS_ERR(data->lpm_clk)) {
169 		dev_err(dev, "can't get lpm_clk\n");
170 		return PTR_ERR(data->lpm_clk);
171 	}
172 
173 	rate = clk_get_rate(data->usb2_refclk);
174 	rate /= 1000;	/* To KHz */
175 	for (i = 0; i < ARRAY_SIZE(cdns_ti_rate_table); i++) {
176 		if (cdns_ti_rate_table[i] == rate)
177 			break;
178 	}
179 
180 	if (i == ARRAY_SIZE(cdns_ti_rate_table)) {
181 		dev_err(dev, "unsupported usb2_refclk rate: %lu KHz\n", rate);
182 		return -EINVAL;
183 	}
184 
185 	data->usb2_refclk_rate_code = i;
186 	data->vbus_divider = device_property_read_bool(dev, "ti,vbus-divider");
187 	data->usb2_only = device_property_read_bool(dev, "ti,usb2-only");
188 
189 	/*
190 	 * The call below to pm_runtime_get_sync() MIGHT reset hardware, if it
191 	 * detects it as uninitialised. We want to enforce a reset at probe,
192 	 * and so do it manually here. This means the first runtime_resume()
193 	 * will be a no-op.
194 	 */
195 	cdns_ti_reset_and_init_hw(data);
196 
197 	pm_runtime_enable(dev);
198 	error = pm_runtime_get_sync(dev);
199 	if (error < 0) {
200 		dev_err(dev, "pm_runtime_get_sync failed: %d\n", error);
201 		goto err;
202 	}
203 
204 	error = of_platform_populate(node, NULL, cdns_ti_auxdata, dev);
205 	if (error) {
206 		dev_err(dev, "failed to create children: %d\n", error);
207 		goto err;
208 	}
209 
210 	return 0;
211 
212 err:
213 	pm_runtime_put_sync(data->dev);
214 	pm_runtime_disable(data->dev);
215 
216 	return error;
217 }
218 
219 static int cdns_ti_remove_core(struct device *dev, void *c)
220 {
221 	struct platform_device *pdev = to_platform_device(dev);
222 
223 	platform_device_unregister(pdev);
224 
225 	return 0;
226 }
227 
228 static void cdns_ti_remove(struct platform_device *pdev)
229 {
230 	struct device *dev = &pdev->dev;
231 
232 	device_for_each_child(dev, NULL, cdns_ti_remove_core);
233 	pm_runtime_put_sync(dev);
234 	pm_runtime_disable(dev);
235 
236 	platform_set_drvdata(pdev, NULL);
237 }
238 
239 static int cdns_ti_runtime_resume(struct device *dev)
240 {
241 	const u32 mask = USBSS_W1_PWRUP_RST | USBSS_W1_MODESTRAP_SEL;
242 	struct cdns_ti *data = dev_get_drvdata(dev);
243 	u32 w1;
244 
245 	w1 = cdns_ti_readl(data, USBSS_W1);
246 	if ((w1 & mask) != mask)
247 		cdns_ti_reset_and_init_hw(data);
248 
249 	return 0;
250 }
251 
252 static const struct dev_pm_ops cdns_ti_pm_ops = {
253 	RUNTIME_PM_OPS(NULL, cdns_ti_runtime_resume, NULL)
254 	SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, pm_runtime_force_resume)
255 };
256 
257 static const struct of_device_id cdns_ti_of_match[] = {
258 	{ .compatible = "ti,j721e-usb", },
259 	{ .compatible = "ti,am64-usb", },
260 	{},
261 };
262 MODULE_DEVICE_TABLE(of, cdns_ti_of_match);
263 
264 static struct platform_driver cdns_ti_driver = {
265 	.probe		= cdns_ti_probe,
266 	.remove		= cdns_ti_remove,
267 	.driver		= {
268 		.name	= "cdns3-ti",
269 		.of_match_table	= cdns_ti_of_match,
270 		.pm     = pm_ptr(&cdns_ti_pm_ops),
271 	},
272 };
273 
274 module_platform_driver(cdns_ti_driver);
275 
276 MODULE_ALIAS("platform:cdns3-ti");
277 MODULE_AUTHOR("Roger Quadros <rogerq@ti.com>");
278 MODULE_LICENSE("GPL v2");
279 MODULE_DESCRIPTION("Cadence USB3 TI Glue Layer");
280