xref: /openbmc/linux/drivers/usb/dwc3/dwc3-st.c (revision 6774def6) 
1 /**
2  * dwc3-st.c Support for dwc3 platform devices on ST Microelectronics platforms
3  *
4  * This is a small driver for the dwc3 to provide the glue logic
5  * to configure the controller. Tested on STi platforms.
6  *
7  * Copyright (C) 2014 Stmicroelectronics
8  *
9  * Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>
10  * Contributors: Aymen Bouattay <aymen.bouattay@st.com>
11  *               Peter Griffin <peter.griffin@linaro.org>
12  *
13  * This program is free software; you can redistribute it and/or modify
14  * it under the terms of the GNU General Public License as published by
15  * the Free Software Foundation; either version 2 of the License, or
16  * (at your option) any later version.
17  *
18  * Inspired by dwc3-omap.c and dwc3-exynos.c.
19  */
20 
21 #include <linux/delay.h>
22 #include <linux/interrupt.h>
23 #include <linux/io.h>
24 #include <linux/ioport.h>
25 #include <linux/kernel.h>
26 #include <linux/mfd/syscon.h>
27 #include <linux/module.h>
28 #include <linux/of.h>
29 #include <linux/of_platform.h>
30 #include <linux/platform_device.h>
31 #include <linux/slab.h>
32 #include <linux/regmap.h>
33 #include <linux/reset.h>
34 #include <linux/usb/of.h>
35 
36 #include "core.h"
37 #include "io.h"
38 
39 /* glue registers */
40 #define CLKRST_CTRL		0x00
41 #define AUX_CLK_EN		BIT(0)
42 #define SW_PIPEW_RESET_N	BIT(4)
43 #define EXT_CFG_RESET_N		BIT(8)
44 /*
45  * 1'b0 : The host controller complies with the xHCI revision 0.96
46  * 1'b1 : The host controller complies with the xHCI revision 1.0
47  */
48 #define XHCI_REVISION		BIT(12)
49 
50 #define USB2_VBUS_MNGMNT_SEL1	0x2C
51 /*
52  * For all fields in USB2_VBUS_MNGMNT_SEL1
53  * 2’b00 : Override value from Reg 0x30 is selected
54  * 2’b01 : utmiotg_<signal_name> from usb3_top is selected
55  * 2’b10 : pipew_<signal_name> from PIPEW instance is selected
56  * 2’b11 : value is 1'b0
57  */
58 #define USB2_VBUS_REG30		0x0
59 #define USB2_VBUS_UTMIOTG	0x1
60 #define USB2_VBUS_PIPEW		0x2
61 #define USB2_VBUS_ZERO		0x3
62 
63 #define SEL_OVERRIDE_VBUSVALID(n)	(n << 0)
64 #define SEL_OVERRIDE_POWERPRESENT(n)	(n << 4)
65 #define SEL_OVERRIDE_BVALID(n)		(n << 8)
66 
67 /* Static DRD configuration */
68 #define USB3_CONTROL_MASK		0xf77
69 
70 #define USB3_DEVICE_NOT_HOST		BIT(0)
71 #define USB3_FORCE_VBUSVALID		BIT(1)
72 #define USB3_DELAY_VBUSVALID		BIT(2)
73 #define USB3_SEL_FORCE_OPMODE		BIT(4)
74 #define USB3_FORCE_OPMODE(n)		(n << 5)
75 #define USB3_SEL_FORCE_DPPULLDOWN2	BIT(8)
76 #define USB3_FORCE_DPPULLDOWN2		BIT(9)
77 #define USB3_SEL_FORCE_DMPULLDOWN2	BIT(10)
78 #define USB3_FORCE_DMPULLDOWN2		BIT(11)
79 
80 /**
81  * struct st_dwc3 - dwc3-st driver private structure
82  * @dev:		device pointer
83  * @glue_base:		ioaddr for the glue registers
84  * @regmap:		regmap pointer for getting syscfg
85  * @syscfg_reg_off:	usb syscfg control offset
86  * @dr_mode:		drd static host/device config
87  * @rstc_pwrdn:		rest controller for powerdown signal
88  * @rstc_rst:		reset controller for softreset signal
89  */
90 
91 struct st_dwc3 {
92 	struct device *dev;
93 	void __iomem *glue_base;
94 	struct regmap *regmap;
95 	int syscfg_reg_off;
96 	enum usb_dr_mode dr_mode;
97 	struct reset_control *rstc_pwrdn;
98 	struct reset_control *rstc_rst;
99 };
100 
101 static inline u32 st_dwc3_readl(void __iomem *base, u32 offset)
102 {
103 	return readl_relaxed(base + offset);
104 }
105 
106 static inline void st_dwc3_writel(void __iomem *base, u32 offset, u32 value)
107 {
108 	writel_relaxed(value, base + offset);
109 }
110 
111 /**
112  * st_dwc3_drd_init: program the port
113  * @dwc3_data: driver private structure
114  * Description: this function is to program the port as either host or device
115  * according to the static configuration passed from devicetree.
116  * OTG and dual role are not yet supported!
117  */
118 static int st_dwc3_drd_init(struct st_dwc3 *dwc3_data)
119 {
120 	u32 val;
121 	int err;
122 
123 	err = regmap_read(dwc3_data->regmap, dwc3_data->syscfg_reg_off, &val);
124 	if (err)
125 		return err;
126 
127 	val &= USB3_CONTROL_MASK;
128 
129 	switch (dwc3_data->dr_mode) {
130 	case USB_DR_MODE_PERIPHERAL:
131 
132 		val &= ~(USB3_FORCE_VBUSVALID | USB3_DELAY_VBUSVALID
133 			| USB3_SEL_FORCE_OPMODE | USB3_FORCE_OPMODE(0x3)
134 			| USB3_SEL_FORCE_DPPULLDOWN2 | USB3_FORCE_DPPULLDOWN2
135 			| USB3_SEL_FORCE_DMPULLDOWN2 | USB3_FORCE_DMPULLDOWN2);
136 
137 		val |= USB3_DEVICE_NOT_HOST;
138 
139 		dev_dbg(dwc3_data->dev, "Configuring as Device\n");
140 		break;
141 
142 	case USB_DR_MODE_HOST:
143 
144 		val &= ~(USB3_DEVICE_NOT_HOST | USB3_FORCE_VBUSVALID
145 			| USB3_SEL_FORCE_OPMODE	| USB3_FORCE_OPMODE(0x3)
146 			| USB3_SEL_FORCE_DPPULLDOWN2 | USB3_FORCE_DPPULLDOWN2
147 			| USB3_SEL_FORCE_DMPULLDOWN2 | USB3_FORCE_DMPULLDOWN2);
148 
149 		/*
150 		 * USB3_DELAY_VBUSVALID is ANDed with USB_C_VBUSVALID. Thus,
151 		 * when set to ‘0‘, it can delay the arrival of VBUSVALID
152 		 * information to VBUSVLDEXT2 input of the pico PHY.
153 		 * We don't want to do that so we set the bit to '1'.
154 		 */
155 
156 		val |= USB3_DELAY_VBUSVALID;
157 
158 		dev_dbg(dwc3_data->dev, "Configuring as Host\n");
159 		break;
160 
161 	default:
162 		dev_err(dwc3_data->dev, "Unsupported mode of operation %d\n",
163 			dwc3_data->dr_mode);
164 		return -EINVAL;
165 	}
166 
167 	return regmap_write(dwc3_data->regmap, dwc3_data->syscfg_reg_off, val);
168 }
169 
170 /**
171  * st_dwc3_init: init the controller via glue logic
172  * @dwc3_data: driver private structure
173  */
174 static void st_dwc3_init(struct st_dwc3 *dwc3_data)
175 {
176 	u32 reg = st_dwc3_readl(dwc3_data->glue_base, CLKRST_CTRL);
177 
178 	reg |= AUX_CLK_EN | EXT_CFG_RESET_N | XHCI_REVISION;
179 	reg &= ~SW_PIPEW_RESET_N;
180 	st_dwc3_writel(dwc3_data->glue_base, CLKRST_CTRL, reg);
181 
182 	/* configure mux for vbus, powerpresent and bvalid signals */
183 	reg = st_dwc3_readl(dwc3_data->glue_base, USB2_VBUS_MNGMNT_SEL1);
184 
185 	reg |= SEL_OVERRIDE_VBUSVALID(USB2_VBUS_UTMIOTG) |
186 		SEL_OVERRIDE_POWERPRESENT(USB2_VBUS_UTMIOTG) |
187 		SEL_OVERRIDE_BVALID(USB2_VBUS_UTMIOTG);
188 
189 	st_dwc3_writel(dwc3_data->glue_base, USB2_VBUS_MNGMNT_SEL1, reg);
190 
191 	reg = st_dwc3_readl(dwc3_data->glue_base, CLKRST_CTRL);
192 	reg |= SW_PIPEW_RESET_N;
193 	st_dwc3_writel(dwc3_data->glue_base, CLKRST_CTRL, reg);
194 }
195 
196 static int st_dwc3_probe(struct platform_device *pdev)
197 {
198 	struct st_dwc3 *dwc3_data;
199 	struct resource *res;
200 	struct device *dev = &pdev->dev;
201 	struct device_node *node = dev->of_node, *child;
202 	struct regmap *regmap;
203 	int ret;
204 
205 	dwc3_data = devm_kzalloc(dev, sizeof(*dwc3_data), GFP_KERNEL);
206 	if (!dwc3_data)
207 		return -ENOMEM;
208 
209 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "reg-glue");
210 	dwc3_data->glue_base = devm_ioremap_resource(dev, res);
211 	if (IS_ERR(dwc3_data->glue_base))
212 		return PTR_ERR(dwc3_data->glue_base);
213 
214 	regmap = syscon_regmap_lookup_by_phandle(node, "st,syscfg");
215 	if (IS_ERR(regmap))
216 		return PTR_ERR(regmap);
217 
218 	dma_set_coherent_mask(dev, dev->coherent_dma_mask);
219 	dwc3_data->dev = dev;
220 	dwc3_data->regmap = regmap;
221 
222 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "syscfg-reg");
223 	if (!res) {
224 		ret = -ENXIO;
225 		goto undo_platform_dev_alloc;
226 	}
227 
228 	dwc3_data->syscfg_reg_off = res->start;
229 
230 	dev_vdbg(&pdev->dev, "glue-logic addr 0x%p, syscfg-reg offset 0x%x\n",
231 		 dwc3_data->glue_base, dwc3_data->syscfg_reg_off);
232 
233 	dwc3_data->rstc_pwrdn = devm_reset_control_get(dev, "powerdown");
234 	if (IS_ERR(dwc3_data->rstc_pwrdn)) {
235 		dev_err(&pdev->dev, "could not get power controller\n");
236 		ret = PTR_ERR(dwc3_data->rstc_pwrdn);
237 		goto undo_platform_dev_alloc;
238 	}
239 
240 	/* Manage PowerDown */
241 	reset_control_deassert(dwc3_data->rstc_pwrdn);
242 
243 	dwc3_data->rstc_rst = devm_reset_control_get(dev, "softreset");
244 	if (IS_ERR(dwc3_data->rstc_rst)) {
245 		dev_err(&pdev->dev, "could not get reset controller\n");
246 		ret = PTR_ERR(dwc3_data->rstc_pwrdn);
247 		goto undo_powerdown;
248 	}
249 
250 	/* Manage SoftReset */
251 	reset_control_deassert(dwc3_data->rstc_rst);
252 
253 	child = of_get_child_by_name(node, "dwc3");
254 	if (!child) {
255 		dev_err(&pdev->dev, "failed to find dwc3 core node\n");
256 		ret = -ENODEV;
257 		goto undo_softreset;
258 	}
259 
260 	dwc3_data->dr_mode = of_usb_get_dr_mode(child);
261 
262 	/* Allocate and initialize the core */
263 	ret = of_platform_populate(node, NULL, NULL, dev);
264 	if (ret) {
265 		dev_err(dev, "failed to add dwc3 core\n");
266 		goto undo_softreset;
267 	}
268 
269 	/*
270 	 * Configure the USB port as device or host according to the static
271 	 * configuration passed from DT.
272 	 * DRD is the only mode currently supported so this will be enhanced
273 	 * as soon as OTG is available.
274 	 */
275 	ret = st_dwc3_drd_init(dwc3_data);
276 	if (ret) {
277 		dev_err(dev, "drd initialisation failed\n");
278 		goto undo_softreset;
279 	}
280 
281 	/* ST glue logic init */
282 	st_dwc3_init(dwc3_data);
283 
284 	platform_set_drvdata(pdev, dwc3_data);
285 	return 0;
286 
287 undo_softreset:
288 	reset_control_assert(dwc3_data->rstc_rst);
289 undo_powerdown:
290 	reset_control_assert(dwc3_data->rstc_pwrdn);
291 undo_platform_dev_alloc:
292 	platform_device_put(pdev);
293 	return ret;
294 }
295 
296 static int st_dwc3_remove(struct platform_device *pdev)
297 {
298 	struct st_dwc3 *dwc3_data = platform_get_drvdata(pdev);
299 
300 	of_platform_depopulate(&pdev->dev);
301 
302 	reset_control_assert(dwc3_data->rstc_pwrdn);
303 	reset_control_assert(dwc3_data->rstc_rst);
304 
305 	return 0;
306 }
307 
308 #ifdef CONFIG_PM_SLEEP
309 static int st_dwc3_suspend(struct device *dev)
310 {
311 	struct st_dwc3 *dwc3_data = dev_get_drvdata(dev);
312 
313 	reset_control_assert(dwc3_data->rstc_pwrdn);
314 	reset_control_assert(dwc3_data->rstc_rst);
315 
316 	pinctrl_pm_select_sleep_state(dev);
317 
318 	return 0;
319 }
320 
321 static int st_dwc3_resume(struct device *dev)
322 {
323 	struct st_dwc3 *dwc3_data = dev_get_drvdata(dev);
324 	int ret;
325 
326 	pinctrl_pm_select_default_state(dev);
327 
328 	reset_control_deassert(dwc3_data->rstc_pwrdn);
329 	reset_control_deassert(dwc3_data->rstc_rst);
330 
331 	ret = st_dwc3_drd_init(dwc3_data);
332 	if (ret) {
333 		dev_err(dev, "drd initialisation failed\n");
334 		return ret;
335 	}
336 
337 	/* ST glue logic init */
338 	st_dwc3_init(dwc3_data);
339 
340 	return 0;
341 }
342 #endif /* CONFIG_PM_SLEEP */
343 
344 static SIMPLE_DEV_PM_OPS(st_dwc3_dev_pm_ops, st_dwc3_suspend, st_dwc3_resume);
345 
346 static const struct of_device_id st_dwc3_match[] = {
347 	{ .compatible = "st,stih407-dwc3" },
348 	{ /* sentinel */ },
349 };
350 
351 MODULE_DEVICE_TABLE(of, st_dwc3_match);
352 
353 static struct platform_driver st_dwc3_driver = {
354 	.probe = st_dwc3_probe,
355 	.remove = st_dwc3_remove,
356 	.driver = {
357 		.name = "usb-st-dwc3",
358 		.of_match_table = st_dwc3_match,
359 		.pm = &st_dwc3_dev_pm_ops,
360 	},
361 };
362 
363 module_platform_driver(st_dwc3_driver);
364 
365 MODULE_AUTHOR("Giuseppe Cavallaro <peppe.cavallaro@st.com>");
366 MODULE_DESCRIPTION("DesignWare USB3 STi Glue Layer");
367 MODULE_LICENSE("GPL v2");
368