xref: /openbmc/linux/drivers/usb/dwc3/dwc3-st.c (revision 2ebbc975) 
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * dwc3-st.c Support for dwc3 platform devices on ST Microelectronics platforms
4  *
5  * This is a small driver for the dwc3 to provide the glue logic
6  * to configure the controller. Tested on STi platforms.
7  *
8  * Copyright (C) 2014 Stmicroelectronics
9  *
10  * Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>
11  * Contributors: Aymen Bouattay <aymen.bouattay@st.com>
12  *               Peter Griffin <peter.griffin@linaro.org>
13  *
14  * Inspired by dwc3-omap.c and dwc3-exynos.c.
15  */
16 
17 #include <linux/delay.h>
18 #include <linux/interrupt.h>
19 #include <linux/io.h>
20 #include <linux/ioport.h>
21 #include <linux/kernel.h>
22 #include <linux/mfd/syscon.h>
23 #include <linux/module.h>
24 #include <linux/of.h>
25 #include <linux/of_platform.h>
26 #include <linux/platform_device.h>
27 #include <linux/slab.h>
28 #include <linux/regmap.h>
29 #include <linux/reset.h>
30 #include <linux/pinctrl/consumer.h>
31 #include <linux/usb/of.h>
32 
33 #include "core.h"
34 #include "io.h"
35 
36 /* glue registers */
37 #define CLKRST_CTRL		0x00
38 #define AUX_CLK_EN		BIT(0)
39 #define SW_PIPEW_RESET_N	BIT(4)
40 #define EXT_CFG_RESET_N		BIT(8)
41 /*
42  * 1'b0 : The host controller complies with the xHCI revision 0.96
43  * 1'b1 : The host controller complies with the xHCI revision 1.0
44  */
45 #define XHCI_REVISION		BIT(12)
46 
47 #define USB2_VBUS_MNGMNT_SEL1	0x2C
48 /*
49  * For all fields in USB2_VBUS_MNGMNT_SEL1
50  * 2’b00 : Override value from Reg 0x30 is selected
51  * 2’b01 : utmiotg_<signal_name> from usb3_top is selected
52  * 2’b10 : pipew_<signal_name> from PIPEW instance is selected
53  * 2’b11 : value is 1'b0
54  */
55 #define USB2_VBUS_REG30		0x0
56 #define USB2_VBUS_UTMIOTG	0x1
57 #define USB2_VBUS_PIPEW		0x2
58 #define USB2_VBUS_ZERO		0x3
59 
60 #define SEL_OVERRIDE_VBUSVALID(n)	(n << 0)
61 #define SEL_OVERRIDE_POWERPRESENT(n)	(n << 4)
62 #define SEL_OVERRIDE_BVALID(n)		(n << 8)
63 
64 /* Static DRD configuration */
65 #define USB3_CONTROL_MASK		0xf77
66 
67 #define USB3_DEVICE_NOT_HOST		BIT(0)
68 #define USB3_FORCE_VBUSVALID		BIT(1)
69 #define USB3_DELAY_VBUSVALID		BIT(2)
70 #define USB3_SEL_FORCE_OPMODE		BIT(4)
71 #define USB3_FORCE_OPMODE(n)		(n << 5)
72 #define USB3_SEL_FORCE_DPPULLDOWN2	BIT(8)
73 #define USB3_FORCE_DPPULLDOWN2		BIT(9)
74 #define USB3_SEL_FORCE_DMPULLDOWN2	BIT(10)
75 #define USB3_FORCE_DMPULLDOWN2		BIT(11)
76 
77 /**
78  * struct st_dwc3 - dwc3-st driver private structure
79  * @dev:		device pointer
80  * @glue_base:		ioaddr for the glue registers
81  * @regmap:		regmap pointer for getting syscfg
82  * @syscfg_reg_off:	usb syscfg control offset
83  * @dr_mode:		drd static host/device config
84  * @rstc_pwrdn:		rest controller for powerdown signal
85  * @rstc_rst:		reset controller for softreset signal
86  */
87 
88 struct st_dwc3 {
89 	struct device *dev;
90 	void __iomem *glue_base;
91 	struct regmap *regmap;
92 	int syscfg_reg_off;
93 	enum usb_dr_mode dr_mode;
94 	struct reset_control *rstc_pwrdn;
95 	struct reset_control *rstc_rst;
96 };
97 
98 static inline u32 st_dwc3_readl(void __iomem *base, u32 offset)
99 {
100 	return readl_relaxed(base + offset);
101 }
102 
103 static inline void st_dwc3_writel(void __iomem *base, u32 offset, u32 value)
104 {
105 	writel_relaxed(value, base + offset);
106 }
107 
108 /**
109  * st_dwc3_drd_init: program the port
110  * @dwc3_data: driver private structure
111  * Description: this function is to program the port as either host or device
112  * according to the static configuration passed from devicetree.
113  * OTG and dual role are not yet supported!
114  */
115 static int st_dwc3_drd_init(struct st_dwc3 *dwc3_data)
116 {
117 	u32 val;
118 	int err;
119 
120 	err = regmap_read(dwc3_data->regmap, dwc3_data->syscfg_reg_off, &val);
121 	if (err)
122 		return err;
123 
124 	val &= USB3_CONTROL_MASK;
125 
126 	switch (dwc3_data->dr_mode) {
127 	case USB_DR_MODE_PERIPHERAL:
128 
129 		val &= ~(USB3_DELAY_VBUSVALID
130 			| USB3_SEL_FORCE_OPMODE | USB3_FORCE_OPMODE(0x3)
131 			| USB3_SEL_FORCE_DPPULLDOWN2 | USB3_FORCE_DPPULLDOWN2
132 			| USB3_SEL_FORCE_DMPULLDOWN2 | USB3_FORCE_DMPULLDOWN2);
133 
134 		/*
135 		 * USB3_PORT2_FORCE_VBUSVALID When '1' and when
136 		 * USB3_PORT2_DEVICE_NOT_HOST = 1, forces VBUSVLDEXT2 input
137 		 * of the pico PHY to 1.
138 		 */
139 
140 		val |= USB3_DEVICE_NOT_HOST | USB3_FORCE_VBUSVALID;
141 		break;
142 
143 	case USB_DR_MODE_HOST:
144 
145 		val &= ~(USB3_DEVICE_NOT_HOST | USB3_FORCE_VBUSVALID
146 			| USB3_SEL_FORCE_OPMODE	| USB3_FORCE_OPMODE(0x3)
147 			| USB3_SEL_FORCE_DPPULLDOWN2 | USB3_FORCE_DPPULLDOWN2
148 			| USB3_SEL_FORCE_DMPULLDOWN2 | USB3_FORCE_DMPULLDOWN2);
149 
150 		/*
151 		 * USB3_DELAY_VBUSVALID is ANDed with USB_C_VBUSVALID. Thus,
152 		 * when set to ‘0‘, it can delay the arrival of VBUSVALID
153 		 * information to VBUSVLDEXT2 input of the pico PHY.
154 		 * We don't want to do that so we set the bit to '1'.
155 		 */
156 
157 		val |= USB3_DELAY_VBUSVALID;
158 		break;
159 
160 	default:
161 		dev_err(dwc3_data->dev, "Unsupported mode of operation %d\n",
162 			dwc3_data->dr_mode);
163 		return -EINVAL;
164 	}
165 
166 	return regmap_write(dwc3_data->regmap, dwc3_data->syscfg_reg_off, val);
167 }
168 
169 /**
170  * st_dwc3_init: init the controller via glue logic
171  * @dwc3_data: driver private structure
172  */
173 static void st_dwc3_init(struct st_dwc3 *dwc3_data)
174 {
175 	u32 reg = st_dwc3_readl(dwc3_data->glue_base, CLKRST_CTRL);
176 
177 	reg |= AUX_CLK_EN | EXT_CFG_RESET_N | XHCI_REVISION;
178 	reg &= ~SW_PIPEW_RESET_N;
179 	st_dwc3_writel(dwc3_data->glue_base, CLKRST_CTRL, reg);
180 
181 	/* configure mux for vbus, powerpresent and bvalid signals */
182 	reg = st_dwc3_readl(dwc3_data->glue_base, USB2_VBUS_MNGMNT_SEL1);
183 
184 	reg |= SEL_OVERRIDE_VBUSVALID(USB2_VBUS_UTMIOTG) |
185 		SEL_OVERRIDE_POWERPRESENT(USB2_VBUS_UTMIOTG) |
186 		SEL_OVERRIDE_BVALID(USB2_VBUS_UTMIOTG);
187 
188 	st_dwc3_writel(dwc3_data->glue_base, USB2_VBUS_MNGMNT_SEL1, reg);
189 
190 	reg = st_dwc3_readl(dwc3_data->glue_base, CLKRST_CTRL);
191 	reg |= SW_PIPEW_RESET_N;
192 	st_dwc3_writel(dwc3_data->glue_base, CLKRST_CTRL, reg);
193 }
194 
195 static int st_dwc3_probe(struct platform_device *pdev)
196 {
197 	struct st_dwc3 *dwc3_data;
198 	struct resource *res;
199 	struct device *dev = &pdev->dev;
200 	struct device_node *node = dev->of_node, *child;
201 	struct platform_device *child_pdev;
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 	dwc3_data->glue_base =
210 		devm_platform_ioremap_resource_byname(pdev, "reg-glue");
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 	dwc3_data->dev = dev;
219 	dwc3_data->regmap = regmap;
220 
221 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "syscfg-reg");
222 	if (!res) {
223 		ret = -ENXIO;
224 		goto undo_platform_dev_alloc;
225 	}
226 
227 	dwc3_data->syscfg_reg_off = res->start;
228 
229 	dev_vdbg(&pdev->dev, "glue-logic addr 0x%pK, syscfg-reg offset 0x%x\n",
230 		 dwc3_data->glue_base, dwc3_data->syscfg_reg_off);
231 
232 	dwc3_data->rstc_pwrdn =
233 		devm_reset_control_get_exclusive(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 =
244 		devm_reset_control_get_shared(dev, "softreset");
245 	if (IS_ERR(dwc3_data->rstc_rst)) {
246 		dev_err(&pdev->dev, "could not get reset controller\n");
247 		ret = PTR_ERR(dwc3_data->rstc_rst);
248 		goto undo_powerdown;
249 	}
250 
251 	/* Manage SoftReset */
252 	reset_control_deassert(dwc3_data->rstc_rst);
253 
254 	child = of_get_compatible_child(node, "snps,dwc3");
255 	if (!child) {
256 		dev_err(&pdev->dev, "failed to find dwc3 core node\n");
257 		ret = -ENODEV;
258 		goto err_node_put;
259 	}
260 
261 	/* Allocate and initialize the core */
262 	ret = of_platform_populate(node, NULL, NULL, dev);
263 	if (ret) {
264 		dev_err(dev, "failed to add dwc3 core\n");
265 		goto err_node_put;
266 	}
267 
268 	child_pdev = of_find_device_by_node(child);
269 	if (!child_pdev) {
270 		dev_err(dev, "failed to find dwc3 core device\n");
271 		ret = -ENODEV;
272 		goto err_node_put;
273 	}
274 
275 	dwc3_data->dr_mode = usb_get_dr_mode(&child_pdev->dev);
276 	of_node_put(child);
277 	platform_device_put(child_pdev);
278 
279 	/*
280 	 * Configure the USB port as device or host according to the static
281 	 * configuration passed from DT.
282 	 * DRD is the only mode currently supported so this will be enhanced
283 	 * as soon as OTG is available.
284 	 */
285 	ret = st_dwc3_drd_init(dwc3_data);
286 	if (ret) {
287 		dev_err(dev, "drd initialisation failed\n");
288 		goto undo_softreset;
289 	}
290 
291 	/* ST glue logic init */
292 	st_dwc3_init(dwc3_data);
293 
294 	platform_set_drvdata(pdev, dwc3_data);
295 	return 0;
296 
297 err_node_put:
298 	of_node_put(child);
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 void 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 
318 #ifdef CONFIG_PM_SLEEP
319 static int st_dwc3_suspend(struct device *dev)
320 {
321 	struct st_dwc3 *dwc3_data = dev_get_drvdata(dev);
322 
323 	reset_control_assert(dwc3_data->rstc_pwrdn);
324 	reset_control_assert(dwc3_data->rstc_rst);
325 
326 	pinctrl_pm_select_sleep_state(dev);
327 
328 	return 0;
329 }
330 
331 static int st_dwc3_resume(struct device *dev)
332 {
333 	struct st_dwc3 *dwc3_data = dev_get_drvdata(dev);
334 	int ret;
335 
336 	pinctrl_pm_select_default_state(dev);
337 
338 	reset_control_deassert(dwc3_data->rstc_pwrdn);
339 	reset_control_deassert(dwc3_data->rstc_rst);
340 
341 	ret = st_dwc3_drd_init(dwc3_data);
342 	if (ret) {
343 		dev_err(dev, "drd initialisation failed\n");
344 		return ret;
345 	}
346 
347 	/* ST glue logic init */
348 	st_dwc3_init(dwc3_data);
349 
350 	return 0;
351 }
352 #endif /* CONFIG_PM_SLEEP */
353 
354 static SIMPLE_DEV_PM_OPS(st_dwc3_dev_pm_ops, st_dwc3_suspend, st_dwc3_resume);
355 
356 static const struct of_device_id st_dwc3_match[] = {
357 	{ .compatible = "st,stih407-dwc3" },
358 	{ /* sentinel */ },
359 };
360 
361 MODULE_DEVICE_TABLE(of, st_dwc3_match);
362 
363 static struct platform_driver st_dwc3_driver = {
364 	.probe = st_dwc3_probe,
365 	.remove_new = st_dwc3_remove,
366 	.driver = {
367 		.name = "usb-st-dwc3",
368 		.of_match_table = st_dwc3_match,
369 		.pm = &st_dwc3_dev_pm_ops,
370 	},
371 };
372 
373 module_platform_driver(st_dwc3_driver);
374 
375 MODULE_AUTHOR("Giuseppe Cavallaro <peppe.cavallaro@st.com>");
376 MODULE_DESCRIPTION("DesignWare USB3 STi Glue Layer");
377 MODULE_LICENSE("GPL v2");
378