xref: /openbmc/linux/drivers/usb/dwc3/dwc3-st.c (revision 8730046c) 
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/pinctrl/consumer.h>
35 #include <linux/usb/of.h>
36 
37 #include "core.h"
38 #include "io.h"
39 
40 /* glue registers */
41 #define CLKRST_CTRL		0x00
42 #define AUX_CLK_EN		BIT(0)
43 #define SW_PIPEW_RESET_N	BIT(4)
44 #define EXT_CFG_RESET_N		BIT(8)
45 /*
46  * 1'b0 : The host controller complies with the xHCI revision 0.96
47  * 1'b1 : The host controller complies with the xHCI revision 1.0
48  */
49 #define XHCI_REVISION		BIT(12)
50 
51 #define USB2_VBUS_MNGMNT_SEL1	0x2C
52 /*
53  * For all fields in USB2_VBUS_MNGMNT_SEL1
54  * 2’b00 : Override value from Reg 0x30 is selected
55  * 2’b01 : utmiotg_<signal_name> from usb3_top is selected
56  * 2’b10 : pipew_<signal_name> from PIPEW instance is selected
57  * 2’b11 : value is 1'b0
58  */
59 #define USB2_VBUS_REG30		0x0
60 #define USB2_VBUS_UTMIOTG	0x1
61 #define USB2_VBUS_PIPEW		0x2
62 #define USB2_VBUS_ZERO		0x3
63 
64 #define SEL_OVERRIDE_VBUSVALID(n)	(n << 0)
65 #define SEL_OVERRIDE_POWERPRESENT(n)	(n << 4)
66 #define SEL_OVERRIDE_BVALID(n)		(n << 8)
67 
68 /* Static DRD configuration */
69 #define USB3_CONTROL_MASK		0xf77
70 
71 #define USB3_DEVICE_NOT_HOST		BIT(0)
72 #define USB3_FORCE_VBUSVALID		BIT(1)
73 #define USB3_DELAY_VBUSVALID		BIT(2)
74 #define USB3_SEL_FORCE_OPMODE		BIT(4)
75 #define USB3_FORCE_OPMODE(n)		(n << 5)
76 #define USB3_SEL_FORCE_DPPULLDOWN2	BIT(8)
77 #define USB3_FORCE_DPPULLDOWN2		BIT(9)
78 #define USB3_SEL_FORCE_DMPULLDOWN2	BIT(10)
79 #define USB3_FORCE_DMPULLDOWN2		BIT(11)
80 
81 /**
82  * struct st_dwc3 - dwc3-st driver private structure
83  * @dev:		device pointer
84  * @glue_base:		ioaddr for the glue registers
85  * @regmap:		regmap pointer for getting syscfg
86  * @syscfg_reg_off:	usb syscfg control offset
87  * @dr_mode:		drd static host/device config
88  * @rstc_pwrdn:		rest controller for powerdown signal
89  * @rstc_rst:		reset controller for softreset signal
90  */
91 
92 struct st_dwc3 {
93 	struct device *dev;
94 	void __iomem *glue_base;
95 	struct regmap *regmap;
96 	int syscfg_reg_off;
97 	enum usb_dr_mode dr_mode;
98 	struct reset_control *rstc_pwrdn;
99 	struct reset_control *rstc_rst;
100 };
101 
102 static inline u32 st_dwc3_readl(void __iomem *base, u32 offset)
103 {
104 	return readl_relaxed(base + offset);
105 }
106 
107 static inline void st_dwc3_writel(void __iomem *base, u32 offset, u32 value)
108 {
109 	writel_relaxed(value, base + offset);
110 }
111 
112 /**
113  * st_dwc3_drd_init: program the port
114  * @dwc3_data: driver private structure
115  * Description: this function is to program the port as either host or device
116  * according to the static configuration passed from devicetree.
117  * OTG and dual role are not yet supported!
118  */
119 static int st_dwc3_drd_init(struct st_dwc3 *dwc3_data)
120 {
121 	u32 val;
122 	int err;
123 
124 	err = regmap_read(dwc3_data->regmap, dwc3_data->syscfg_reg_off, &val);
125 	if (err)
126 		return err;
127 
128 	val &= USB3_CONTROL_MASK;
129 
130 	switch (dwc3_data->dr_mode) {
131 	case USB_DR_MODE_PERIPHERAL:
132 
133 		val &= ~(USB3_DELAY_VBUSVALID
134 			| USB3_SEL_FORCE_OPMODE | USB3_FORCE_OPMODE(0x3)
135 			| USB3_SEL_FORCE_DPPULLDOWN2 | USB3_FORCE_DPPULLDOWN2
136 			| USB3_SEL_FORCE_DMPULLDOWN2 | USB3_FORCE_DMPULLDOWN2);
137 
138 		/*
139 		 * USB3_PORT2_FORCE_VBUSVALID When '1' and when
140 		 * USB3_PORT2_DEVICE_NOT_HOST = 1, forces VBUSVLDEXT2 input
141 		 * of the pico PHY to 1.
142 		 */
143 
144 		val |= USB3_DEVICE_NOT_HOST | USB3_FORCE_VBUSVALID;
145 		break;
146 
147 	case USB_DR_MODE_HOST:
148 
149 		val &= ~(USB3_DEVICE_NOT_HOST | USB3_FORCE_VBUSVALID
150 			| USB3_SEL_FORCE_OPMODE	| USB3_FORCE_OPMODE(0x3)
151 			| USB3_SEL_FORCE_DPPULLDOWN2 | USB3_FORCE_DPPULLDOWN2
152 			| USB3_SEL_FORCE_DMPULLDOWN2 | USB3_FORCE_DMPULLDOWN2);
153 
154 		/*
155 		 * USB3_DELAY_VBUSVALID is ANDed with USB_C_VBUSVALID. Thus,
156 		 * when set to ‘0‘, it can delay the arrival of VBUSVALID
157 		 * information to VBUSVLDEXT2 input of the pico PHY.
158 		 * We don't want to do that so we set the bit to '1'.
159 		 */
160 
161 		val |= USB3_DELAY_VBUSVALID;
162 		break;
163 
164 	default:
165 		dev_err(dwc3_data->dev, "Unsupported mode of operation %d\n",
166 			dwc3_data->dr_mode);
167 		return -EINVAL;
168 	}
169 
170 	return regmap_write(dwc3_data->regmap, dwc3_data->syscfg_reg_off, val);
171 }
172 
173 /**
174  * st_dwc3_init: init the controller via glue logic
175  * @dwc3_data: driver private structure
176  */
177 static void st_dwc3_init(struct st_dwc3 *dwc3_data)
178 {
179 	u32 reg = st_dwc3_readl(dwc3_data->glue_base, CLKRST_CTRL);
180 
181 	reg |= AUX_CLK_EN | EXT_CFG_RESET_N | XHCI_REVISION;
182 	reg &= ~SW_PIPEW_RESET_N;
183 	st_dwc3_writel(dwc3_data->glue_base, CLKRST_CTRL, reg);
184 
185 	/* configure mux for vbus, powerpresent and bvalid signals */
186 	reg = st_dwc3_readl(dwc3_data->glue_base, USB2_VBUS_MNGMNT_SEL1);
187 
188 	reg |= SEL_OVERRIDE_VBUSVALID(USB2_VBUS_UTMIOTG) |
189 		SEL_OVERRIDE_POWERPRESENT(USB2_VBUS_UTMIOTG) |
190 		SEL_OVERRIDE_BVALID(USB2_VBUS_UTMIOTG);
191 
192 	st_dwc3_writel(dwc3_data->glue_base, USB2_VBUS_MNGMNT_SEL1, reg);
193 
194 	reg = st_dwc3_readl(dwc3_data->glue_base, CLKRST_CTRL);
195 	reg |= SW_PIPEW_RESET_N;
196 	st_dwc3_writel(dwc3_data->glue_base, CLKRST_CTRL, reg);
197 }
198 
199 static int st_dwc3_probe(struct platform_device *pdev)
200 {
201 	struct st_dwc3 *dwc3_data;
202 	struct resource *res;
203 	struct device *dev = &pdev->dev;
204 	struct device_node *node = dev->of_node, *child;
205 	struct platform_device *child_pdev;
206 	struct regmap *regmap;
207 	int ret;
208 
209 	dwc3_data = devm_kzalloc(dev, sizeof(*dwc3_data), GFP_KERNEL);
210 	if (!dwc3_data)
211 		return -ENOMEM;
212 
213 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "reg-glue");
214 	dwc3_data->glue_base = devm_ioremap_resource(dev, res);
215 	if (IS_ERR(dwc3_data->glue_base))
216 		return PTR_ERR(dwc3_data->glue_base);
217 
218 	regmap = syscon_regmap_lookup_by_phandle(node, "st,syscfg");
219 	if (IS_ERR(regmap))
220 		return PTR_ERR(regmap);
221 
222 	dwc3_data->dev = dev;
223 	dwc3_data->regmap = regmap;
224 
225 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "syscfg-reg");
226 	if (!res) {
227 		ret = -ENXIO;
228 		goto undo_platform_dev_alloc;
229 	}
230 
231 	dwc3_data->syscfg_reg_off = res->start;
232 
233 	dev_vdbg(&pdev->dev, "glue-logic addr 0x%p, syscfg-reg offset 0x%x\n",
234 		 dwc3_data->glue_base, dwc3_data->syscfg_reg_off);
235 
236 	dwc3_data->rstc_pwrdn =
237 		devm_reset_control_get_exclusive(dev, "powerdown");
238 	if (IS_ERR(dwc3_data->rstc_pwrdn)) {
239 		dev_err(&pdev->dev, "could not get power controller\n");
240 		ret = PTR_ERR(dwc3_data->rstc_pwrdn);
241 		goto undo_platform_dev_alloc;
242 	}
243 
244 	/* Manage PowerDown */
245 	reset_control_deassert(dwc3_data->rstc_pwrdn);
246 
247 	dwc3_data->rstc_rst =
248 		devm_reset_control_get_shared(dev, "softreset");
249 	if (IS_ERR(dwc3_data->rstc_rst)) {
250 		dev_err(&pdev->dev, "could not get reset controller\n");
251 		ret = PTR_ERR(dwc3_data->rstc_rst);
252 		goto undo_powerdown;
253 	}
254 
255 	/* Manage SoftReset */
256 	reset_control_deassert(dwc3_data->rstc_rst);
257 
258 	child = of_get_child_by_name(node, "dwc3");
259 	if (!child) {
260 		dev_err(&pdev->dev, "failed to find dwc3 core node\n");
261 		ret = -ENODEV;
262 		goto undo_softreset;
263 	}
264 
265 	/* Allocate and initialize the core */
266 	ret = of_platform_populate(node, NULL, NULL, dev);
267 	if (ret) {
268 		dev_err(dev, "failed to add dwc3 core\n");
269 		goto undo_softreset;
270 	}
271 
272 	child_pdev = of_find_device_by_node(child);
273 	if (!child_pdev) {
274 		dev_err(dev, "failed to find dwc3 core device\n");
275 		ret = -ENODEV;
276 		goto undo_softreset;
277 	}
278 
279 	dwc3_data->dr_mode = usb_get_dr_mode(&child_pdev->dev);
280 
281 	/*
282 	 * Configure the USB port as device or host according to the static
283 	 * configuration passed from DT.
284 	 * DRD is the only mode currently supported so this will be enhanced
285 	 * as soon as OTG is available.
286 	 */
287 	ret = st_dwc3_drd_init(dwc3_data);
288 	if (ret) {
289 		dev_err(dev, "drd initialisation failed\n");
290 		goto undo_softreset;
291 	}
292 
293 	/* ST glue logic init */
294 	st_dwc3_init(dwc3_data);
295 
296 	platform_set_drvdata(pdev, dwc3_data);
297 	return 0;
298 
299 undo_softreset:
300 	reset_control_assert(dwc3_data->rstc_rst);
301 undo_powerdown:
302 	reset_control_assert(dwc3_data->rstc_pwrdn);
303 undo_platform_dev_alloc:
304 	platform_device_put(pdev);
305 	return ret;
306 }
307 
308 static int st_dwc3_remove(struct platform_device *pdev)
309 {
310 	struct st_dwc3 *dwc3_data = platform_get_drvdata(pdev);
311 
312 	of_platform_depopulate(&pdev->dev);
313 
314 	reset_control_assert(dwc3_data->rstc_pwrdn);
315 	reset_control_assert(dwc3_data->rstc_rst);
316 
317 	return 0;
318 }
319 
320 #ifdef CONFIG_PM_SLEEP
321 static int st_dwc3_suspend(struct device *dev)
322 {
323 	struct st_dwc3 *dwc3_data = dev_get_drvdata(dev);
324 
325 	reset_control_assert(dwc3_data->rstc_pwrdn);
326 	reset_control_assert(dwc3_data->rstc_rst);
327 
328 	pinctrl_pm_select_sleep_state(dev);
329 
330 	return 0;
331 }
332 
333 static int st_dwc3_resume(struct device *dev)
334 {
335 	struct st_dwc3 *dwc3_data = dev_get_drvdata(dev);
336 	int ret;
337 
338 	pinctrl_pm_select_default_state(dev);
339 
340 	reset_control_deassert(dwc3_data->rstc_pwrdn);
341 	reset_control_deassert(dwc3_data->rstc_rst);
342 
343 	ret = st_dwc3_drd_init(dwc3_data);
344 	if (ret) {
345 		dev_err(dev, "drd initialisation failed\n");
346 		return ret;
347 	}
348 
349 	/* ST glue logic init */
350 	st_dwc3_init(dwc3_data);
351 
352 	return 0;
353 }
354 #endif /* CONFIG_PM_SLEEP */
355 
356 static SIMPLE_DEV_PM_OPS(st_dwc3_dev_pm_ops, st_dwc3_suspend, st_dwc3_resume);
357 
358 static const struct of_device_id st_dwc3_match[] = {
359 	{ .compatible = "st,stih407-dwc3" },
360 	{ /* sentinel */ },
361 };
362 
363 MODULE_DEVICE_TABLE(of, st_dwc3_match);
364 
365 static struct platform_driver st_dwc3_driver = {
366 	.probe = st_dwc3_probe,
367 	.remove = st_dwc3_remove,
368 	.driver = {
369 		.name = "usb-st-dwc3",
370 		.of_match_table = st_dwc3_match,
371 		.pm = &st_dwc3_dev_pm_ops,
372 	},
373 };
374 
375 module_platform_driver(st_dwc3_driver);
376 
377 MODULE_AUTHOR("Giuseppe Cavallaro <peppe.cavallaro@st.com>");
378 MODULE_DESCRIPTION("DesignWare USB3 STi Glue Layer");
379 MODULE_LICENSE("GPL v2");
380