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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Cadence USBSS DRD Driver.
4 *
5 * Copyright (C) 2018-2019 Cadence.
6 * Copyright (C) 2019 Texas Instruments
7 *
8 * Author: Pawel Laszczak <pawell@cadence.com>
9 * Roger Quadros <rogerq@ti.com>
10 *
11 *
12 */
13#include <linux/kernel.h>
14#include <linux/interrupt.h>
15#include <linux/delay.h>
16#include <linux/iopoll.h>
17#include <linux/usb/otg.h>
18
19#include "gadget.h"
20#include "drd.h"
21#include "core.h"
22
23/**
24 * cdns3_set_mode - change mode of OTG Core
25 * @cdns: pointer to context structure
26 * @mode: selected mode from cdns_role
27 *
28 * Returns 0 on success otherwise negative errno
29 */
30int cdns3_set_mode(struct cdns3 *cdns, enum usb_dr_mode mode)
31{
32 int ret = 0;
33 u32 reg;
34
35 switch (mode) {
36 case USB_DR_MODE_PERIPHERAL:
37 break;
38 case USB_DR_MODE_HOST:
39 break;
40 case USB_DR_MODE_OTG:
41 dev_dbg(cdns->dev, "Set controller to OTG mode\n");
42 if (cdns->version == CDNS3_CONTROLLER_V1) {
43 reg = readl(&cdns->otg_v1_regs->override);
44 reg |= OVERRIDE_IDPULLUP;
45 writel(reg, &cdns->otg_v1_regs->override);
46 } else {
47 reg = readl(&cdns->otg_v0_regs->ctrl1);
48 reg |= OVERRIDE_IDPULLUP_V0;
49 writel(reg, &cdns->otg_v0_regs->ctrl1);
50 }
51
52 /*
53 * Hardware specification says: "ID_VALUE must be valid within
54 * 50ms after idpullup is set to '1" so driver must wait
55 * 50ms before reading this pin.
56 */
57 usleep_range(50000, 60000);
58 break;
59 default:
60 dev_err(cdns->dev, "Unsupported mode of operation %d\n", mode);
61 return -EINVAL;
62 }
63
64 return ret;
65}
66
67int cdns3_get_id(struct cdns3 *cdns)
68{
69 int id;
70
71 id = readl(&cdns->otg_regs->sts) & OTGSTS_ID_VALUE;
72 dev_dbg(cdns->dev, "OTG ID: %d", id);
73
74 return id;
75}
76
77int cdns3_get_vbus(struct cdns3 *cdns)
78{
79 int vbus;
80
81 vbus = !!(readl(&cdns->otg_regs->sts) & OTGSTS_VBUS_VALID);
82 dev_dbg(cdns->dev, "OTG VBUS: %d", vbus);
83
84 return vbus;
85}
86
87int cdns3_is_host(struct cdns3 *cdns)
88{
89 if (cdns->dr_mode == USB_DR_MODE_HOST)
90 return 1;
91 else if (!cdns3_get_id(cdns))
92 return 1;
93
94 return 0;
95}
96
97int cdns3_is_device(struct cdns3 *cdns)
98{
99 if (cdns->dr_mode == USB_DR_MODE_PERIPHERAL)
100 return 1;
101 else if (cdns->dr_mode == USB_DR_MODE_OTG)
102 if (cdns3_get_id(cdns))
103 return 1;
104
105 return 0;
106}
107
108/**
109 * cdns3_otg_disable_irq - Disable all OTG interrupts
110 * @cdns: Pointer to controller context structure
111 */
112static void cdns3_otg_disable_irq(struct cdns3 *cdns)
113{
114 writel(0, &cdns->otg_regs->ien);
115}
116
117/**
118 * cdns3_otg_enable_irq - enable id and sess_valid interrupts
119 * @cdns: Pointer to controller context structure
120 */
121static void cdns3_otg_enable_irq(struct cdns3 *cdns)
122{
123 writel(OTGIEN_ID_CHANGE_INT | OTGIEN_VBUSVALID_RISE_INT |
124 OTGIEN_VBUSVALID_FALL_INT, &cdns->otg_regs->ien);
125}
126
127/**
128 * cdns3_drd_switch_host - start/stop host
129 * @cdns: Pointer to controller context structure
130 * @on: 1 for start, 0 for stop
131 *
132 * Returns 0 on success otherwise negative errno
133 */
134int cdns3_drd_switch_host(struct cdns3 *cdns, int on)
135{
136 int ret, val;
137 u32 reg = OTGCMD_OTG_DIS;
138
139 /* switch OTG core */
140 if (on) {
141 writel(OTGCMD_HOST_BUS_REQ | reg, &cdns->otg_regs->cmd);
142
143 dev_dbg(cdns->dev, "Waiting till Host mode is turned on\n");
144 ret = readl_poll_timeout_atomic(&cdns->otg_regs->sts, val,
145 val & OTGSTS_XHCI_READY,
146 1, 100000);
147 if (ret) {
148 dev_err(cdns->dev, "timeout waiting for xhci_ready\n");
149 return ret;
150 }
151 } else {
152 writel(OTGCMD_HOST_BUS_DROP | OTGCMD_DEV_BUS_DROP |
153 OTGCMD_DEV_POWER_OFF | OTGCMD_HOST_POWER_OFF,
154 &cdns->otg_regs->cmd);
155 /* Waiting till H_IDLE state.*/
156 readl_poll_timeout_atomic(&cdns->otg_regs->state, val,
157 !(val & OTGSTATE_HOST_STATE_MASK),
158 1, 2000000);
159 }
160
161 return 0;
162}
163
164/**
165 * cdns3_drd_switch_gadget - start/stop gadget
166 * @cdns: Pointer to controller context structure
167 * @on: 1 for start, 0 for stop
168 *
169 * Returns 0 on success otherwise negative errno
170 */
171int cdns3_drd_switch_gadget(struct cdns3 *cdns, int on)
172{
173 int ret, val;
174 u32 reg = OTGCMD_OTG_DIS;
175
176 /* switch OTG core */
177 if (on) {
178 writel(OTGCMD_DEV_BUS_REQ | reg, &cdns->otg_regs->cmd);
179
180 dev_dbg(cdns->dev, "Waiting till Device mode is turned on\n");
181
182 ret = readl_poll_timeout_atomic(&cdns->otg_regs->sts, val,
183 val & OTGSTS_DEV_READY,
184 1, 100000);
185 if (ret) {
186 dev_err(cdns->dev, "timeout waiting for dev_ready\n");
187 return ret;
188 }
189 } else {
190 /*
191 * driver should wait at least 10us after disabling Device
192 * before turning-off Device (DEV_BUS_DROP)
193 */
194 usleep_range(20, 30);
195 writel(OTGCMD_HOST_BUS_DROP | OTGCMD_DEV_BUS_DROP |
196 OTGCMD_DEV_POWER_OFF | OTGCMD_HOST_POWER_OFF,
197 &cdns->otg_regs->cmd);
198 /* Waiting till DEV_IDLE state.*/
199 readl_poll_timeout_atomic(&cdns->otg_regs->state, val,
200 !(val & OTGSTATE_DEV_STATE_MASK),
201 1, 2000000);
202 }
203
204 return 0;
205}
206
207/**
208 * cdns3_init_otg_mode - initialize drd controller
209 * @cdns: Pointer to controller context structure
210 *
211 * Returns 0 on success otherwise negative errno
212 */
213static int cdns3_init_otg_mode(struct cdns3 *cdns)
214{
215 int ret = 0;
216
217 cdns3_otg_disable_irq(cdns);
218 /* clear all interrupts */
219 writel(~0, &cdns->otg_regs->ivect);
220
221 ret = cdns3_set_mode(cdns, USB_DR_MODE_OTG);
222 if (ret)
223 return ret;
224
225 cdns3_otg_enable_irq(cdns);
226 return ret;
227}
228
229/**
230 * cdns3_drd_update_mode - initialize mode of operation
231 * @cdns: Pointer to controller context structure
232 *
233 * Returns 0 on success otherwise negative errno
234 */
235int cdns3_drd_update_mode(struct cdns3 *cdns)
236{
237 int ret = 0;
238
239 switch (cdns->dr_mode) {
240 case USB_DR_MODE_PERIPHERAL:
241 ret = cdns3_set_mode(cdns, USB_DR_MODE_PERIPHERAL);
242 break;
243 case USB_DR_MODE_HOST:
244 ret = cdns3_set_mode(cdns, USB_DR_MODE_HOST);
245 break;
246 case USB_DR_MODE_OTG:
247 ret = cdns3_init_otg_mode(cdns);
248 break;
249 default:
250 dev_err(cdns->dev, "Unsupported mode of operation %d\n",
251 cdns->dr_mode);
252 return -EINVAL;
253 }
254
255 return ret;
256}
257
258static irqreturn_t cdns3_drd_thread_irq(int irq, void *data)
259{
260 struct cdns3 *cdns = data;
261
262 cdns3_hw_role_switch(cdns);
263
264 return IRQ_HANDLED;
265}
266
267/**
268 * cdns3_drd_irq - interrupt handler for OTG events
269 *
270 * @irq: irq number for cdns3 core device
271 * @data: structure of cdns3
272 *
273 * Returns IRQ_HANDLED or IRQ_NONE
274 */
275static irqreturn_t cdns3_drd_irq(int irq, void *data)
276{
277 irqreturn_t ret = IRQ_NONE;
278 struct cdns3 *cdns = data;
279 u32 reg;
280
281 if (cdns->dr_mode != USB_DR_MODE_OTG)
282 return ret;
283
284 reg = readl(&cdns->otg_regs->ivect);
285
286 if (!reg)
287 return ret;
288
289 if (reg & OTGIEN_ID_CHANGE_INT) {
290 dev_dbg(cdns->dev, "OTG IRQ: new ID: %d\n",
291 cdns3_get_id(cdns));
292
293 ret = IRQ_WAKE_THREAD;
294 }
295
296 if (reg & (OTGIEN_VBUSVALID_RISE_INT | OTGIEN_VBUSVALID_FALL_INT)) {
297 dev_dbg(cdns->dev, "OTG IRQ: new VBUS: %d\n",
298 cdns3_get_vbus(cdns));
299
300 ret = IRQ_WAKE_THREAD;
301 }
302
303 writel(~0, &cdns->otg_regs->ivect);
304 return ret;
305}
306
307int cdns3_drd_init(struct cdns3 *cdns)
308{
309 void __iomem *regs;
310 int ret = 0;
311 u32 state;
312
313 regs = devm_ioremap_resource(cdns->dev, &cdns->otg_res);
314 if (IS_ERR(regs))
315 return PTR_ERR(regs);
316
317 /* Detection of DRD version. Controller has been released
318 * in two versions. Both are similar, but they have same changes
319 * in register maps.
320 * The first register in old version is command register and it's read
321 * only, so driver should read 0 from it. On the other hand, in v1
322 * the first register contains device ID number which is not set to 0.
323 * Driver uses this fact to detect the proper version of
324 * controller.
325 */
326 cdns->otg_v0_regs = regs;
327 if (!readl(&cdns->otg_v0_regs->cmd)) {
328 cdns->version = CDNS3_CONTROLLER_V0;
329 cdns->otg_v1_regs = NULL;
330 cdns->otg_regs = regs;
331 writel(1, &cdns->otg_v0_regs->simulate);
332 dev_info(cdns->dev, "DRD version v0 (%08x)\n",
333 readl(&cdns->otg_v0_regs->version));
334 } else {
335 cdns->otg_v0_regs = NULL;
336 cdns->otg_v1_regs = regs;
337 cdns->otg_regs = (void *)&cdns->otg_v1_regs->cmd;
338 cdns->version = CDNS3_CONTROLLER_V1;
339 writel(1, &cdns->otg_v1_regs->simulate);
340 dev_info(cdns->dev, "DRD version v1 (ID: %08x, rev: %08x)\n",
341 readl(&cdns->otg_v1_regs->did),
342 readl(&cdns->otg_v1_regs->rid));
343 }
344
345 state = OTGSTS_STRAP(readl(&cdns->otg_regs->sts));
346
347 /* Update dr_mode according to STRAP configuration. */
348 cdns->dr_mode = USB_DR_MODE_OTG;
349 if (state == OTGSTS_STRAP_HOST) {
350 dev_dbg(cdns->dev, "Controller strapped to HOST\n");
351 cdns->dr_mode = USB_DR_MODE_HOST;
352 } else if (state == OTGSTS_STRAP_GADGET) {
353 dev_dbg(cdns->dev, "Controller strapped to PERIPHERAL\n");
354 cdns->dr_mode = USB_DR_MODE_PERIPHERAL;
355 }
356
357 ret = devm_request_threaded_irq(cdns->dev, cdns->otg_irq,
358 cdns3_drd_irq,
359 cdns3_drd_thread_irq,
360 IRQF_SHARED,
361 dev_name(cdns->dev), cdns);
362
363 if (ret) {
364 dev_err(cdns->dev, "couldn't get otg_irq\n");
365 return ret;
366 }
367
368 state = readl(&cdns->otg_regs->sts);
369 if (OTGSTS_OTG_NRDY(state) != 0) {
370 dev_err(cdns->dev, "Cadence USB3 OTG device not ready\n");
371 return -ENODEV;
372 }
373
374 return ret;
375}
376
377int cdns3_drd_exit(struct cdns3 *cdns)
378{
379 cdns3_otg_disable_irq(cdns);
380 return 0;
381}