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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
91struct 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
101static inline u32 st_dwc3_readl(void __iomem *base, u32 offset)
102{
103 return readl_relaxed(base + offset);
104}
105
106static 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 */
118static 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 break;
139
140 case USB_DR_MODE_HOST:
141
142 val &= ~(USB3_DEVICE_NOT_HOST | USB3_FORCE_VBUSVALID
143 | USB3_SEL_FORCE_OPMODE | USB3_FORCE_OPMODE(0x3)
144 | USB3_SEL_FORCE_DPPULLDOWN2 | USB3_FORCE_DPPULLDOWN2
145 | USB3_SEL_FORCE_DMPULLDOWN2 | USB3_FORCE_DMPULLDOWN2);
146
147 /*
148 * USB3_DELAY_VBUSVALID is ANDed with USB_C_VBUSVALID. Thus,
149 * when set to ‘0‘, it can delay the arrival of VBUSVALID
150 * information to VBUSVLDEXT2 input of the pico PHY.
151 * We don't want to do that so we set the bit to '1'.
152 */
153
154 val |= USB3_DELAY_VBUSVALID;
155 break;
156
157 default:
158 dev_err(dwc3_data->dev, "Unsupported mode of operation %d\n",
159 dwc3_data->dr_mode);
160 return -EINVAL;
161 }
162
163 return regmap_write(dwc3_data->regmap, dwc3_data->syscfg_reg_off, val);
164}
165
166/**
167 * st_dwc3_init: init the controller via glue logic
168 * @dwc3_data: driver private structure
169 */
170static void st_dwc3_init(struct st_dwc3 *dwc3_data)
171{
172 u32 reg = st_dwc3_readl(dwc3_data->glue_base, CLKRST_CTRL);
173
174 reg |= AUX_CLK_EN | EXT_CFG_RESET_N | XHCI_REVISION;
175 reg &= ~SW_PIPEW_RESET_N;
176 st_dwc3_writel(dwc3_data->glue_base, CLKRST_CTRL, reg);
177
178 /* configure mux for vbus, powerpresent and bvalid signals */
179 reg = st_dwc3_readl(dwc3_data->glue_base, USB2_VBUS_MNGMNT_SEL1);
180
181 reg |= SEL_OVERRIDE_VBUSVALID(USB2_VBUS_UTMIOTG) |
182 SEL_OVERRIDE_POWERPRESENT(USB2_VBUS_UTMIOTG) |
183 SEL_OVERRIDE_BVALID(USB2_VBUS_UTMIOTG);
184
185 st_dwc3_writel(dwc3_data->glue_base, USB2_VBUS_MNGMNT_SEL1, reg);
186
187 reg = st_dwc3_readl(dwc3_data->glue_base, CLKRST_CTRL);
188 reg |= SW_PIPEW_RESET_N;
189 st_dwc3_writel(dwc3_data->glue_base, CLKRST_CTRL, reg);
190}
191
192static int st_dwc3_probe(struct platform_device *pdev)
193{
194 struct st_dwc3 *dwc3_data;
195 struct resource *res;
196 struct device *dev = &pdev->dev;
197 struct device_node *node = dev->of_node, *child;
198 struct platform_device *child_pdev;
199 struct regmap *regmap;
200 int ret;
201
202 dwc3_data = devm_kzalloc(dev, sizeof(*dwc3_data), GFP_KERNEL);
203 if (!dwc3_data)
204 return -ENOMEM;
205
206 res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "reg-glue");
207 dwc3_data->glue_base = devm_ioremap_resource(dev, res);
208 if (IS_ERR(dwc3_data->glue_base))
209 return PTR_ERR(dwc3_data->glue_base);
210
211 regmap = syscon_regmap_lookup_by_phandle(node, "st,syscfg");
212 if (IS_ERR(regmap))
213 return PTR_ERR(regmap);
214
215 dma_set_coherent_mask(dev, dev->coherent_dma_mask);
216 dwc3_data->dev = dev;
217 dwc3_data->regmap = regmap;
218
219 res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "syscfg-reg");
220 if (!res) {
221 ret = -ENXIO;
222 goto undo_platform_dev_alloc;
223 }
224
225 dwc3_data->syscfg_reg_off = res->start;
226
227 dev_vdbg(&pdev->dev, "glue-logic addr 0x%p, syscfg-reg offset 0x%x\n",
228 dwc3_data->glue_base, dwc3_data->syscfg_reg_off);
229
230 dwc3_data->rstc_pwrdn = devm_reset_control_get(dev, "powerdown");
231 if (IS_ERR(dwc3_data->rstc_pwrdn)) {
232 dev_err(&pdev->dev, "could not get power controller\n");
233 ret = PTR_ERR(dwc3_data->rstc_pwrdn);
234 goto undo_platform_dev_alloc;
235 }
236
237 /* Manage PowerDown */
238 reset_control_deassert(dwc3_data->rstc_pwrdn);
239
240 dwc3_data->rstc_rst = devm_reset_control_get(dev, "softreset");
241 if (IS_ERR(dwc3_data->rstc_rst)) {
242 dev_err(&pdev->dev, "could not get reset controller\n");
243 ret = PTR_ERR(dwc3_data->rstc_rst);
244 goto undo_powerdown;
245 }
246
247 /* Manage SoftReset */
248 reset_control_deassert(dwc3_data->rstc_rst);
249
250 child = of_get_child_by_name(node, "dwc3");
251 if (!child) {
252 dev_err(&pdev->dev, "failed to find dwc3 core node\n");
253 ret = -ENODEV;
254 goto undo_softreset;
255 }
256
257 /* Allocate and initialize the core */
258 ret = of_platform_populate(node, NULL, NULL, dev);
259 if (ret) {
260 dev_err(dev, "failed to add dwc3 core\n");
261 goto undo_softreset;
262 }
263
264 child_pdev = of_find_device_by_node(child);
265 if (!child_pdev) {
266 dev_err(dev, "failed to find dwc3 core device\n");
267 ret = -ENODEV;
268 goto undo_softreset;
269 }
270
271 dwc3_data->dr_mode = usb_get_dr_mode(&child_pdev->dev);
272
273 /*
274 * Configure the USB port as device or host according to the static
275 * configuration passed from DT.
276 * DRD is the only mode currently supported so this will be enhanced
277 * as soon as OTG is available.
278 */
279 ret = st_dwc3_drd_init(dwc3_data);
280 if (ret) {
281 dev_err(dev, "drd initialisation failed\n");
282 goto undo_softreset;
283 }
284
285 /* ST glue logic init */
286 st_dwc3_init(dwc3_data);
287
288 platform_set_drvdata(pdev, dwc3_data);
289 return 0;
290
291undo_softreset:
292 reset_control_assert(dwc3_data->rstc_rst);
293undo_powerdown:
294 reset_control_assert(dwc3_data->rstc_pwrdn);
295undo_platform_dev_alloc:
296 platform_device_put(pdev);
297 return ret;
298}
299
300static int st_dwc3_remove(struct platform_device *pdev)
301{
302 struct st_dwc3 *dwc3_data = platform_get_drvdata(pdev);
303
304 of_platform_depopulate(&pdev->dev);
305
306 reset_control_assert(dwc3_data->rstc_pwrdn);
307 reset_control_assert(dwc3_data->rstc_rst);
308
309 return 0;
310}
311
312#ifdef CONFIG_PM_SLEEP
313static int st_dwc3_suspend(struct device *dev)
314{
315 struct st_dwc3 *dwc3_data = dev_get_drvdata(dev);
316
317 reset_control_assert(dwc3_data->rstc_pwrdn);
318 reset_control_assert(dwc3_data->rstc_rst);
319
320 pinctrl_pm_select_sleep_state(dev);
321
322 return 0;
323}
324
325static int st_dwc3_resume(struct device *dev)
326{
327 struct st_dwc3 *dwc3_data = dev_get_drvdata(dev);
328 int ret;
329
330 pinctrl_pm_select_default_state(dev);
331
332 reset_control_deassert(dwc3_data->rstc_pwrdn);
333 reset_control_deassert(dwc3_data->rstc_rst);
334
335 ret = st_dwc3_drd_init(dwc3_data);
336 if (ret) {
337 dev_err(dev, "drd initialisation failed\n");
338 return ret;
339 }
340
341 /* ST glue logic init */
342 st_dwc3_init(dwc3_data);
343
344 return 0;
345}
346#endif /* CONFIG_PM_SLEEP */
347
348static SIMPLE_DEV_PM_OPS(st_dwc3_dev_pm_ops, st_dwc3_suspend, st_dwc3_resume);
349
350static const struct of_device_id st_dwc3_match[] = {
351 { .compatible = "st,stih407-dwc3" },
352 { /* sentinel */ },
353};
354
355MODULE_DEVICE_TABLE(of, st_dwc3_match);
356
357static struct platform_driver st_dwc3_driver = {
358 .probe = st_dwc3_probe,
359 .remove = st_dwc3_remove,
360 .driver = {
361 .name = "usb-st-dwc3",
362 .of_match_table = st_dwc3_match,
363 .pm = &st_dwc3_dev_pm_ops,
364 },
365};
366
367module_platform_driver(st_dwc3_driver);
368
369MODULE_AUTHOR("Giuseppe Cavallaro <peppe.cavallaro@st.com>");
370MODULE_DESCRIPTION("DesignWare USB3 STi Glue Layer");
371MODULE_LICENSE("GPL v2");