1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Cadence USBSS and USBSSP DRD Driver.
4 *
5 * Copyright (C) 2018-2020 Cadence.
6 * Copyright (C) 2019 Texas Instruments
7 *
8 * Author: Pawel Laszczak <pawell@cadence.com>
9 * Roger Quadros <rogerq@ti.com>
10 *
11 */
12 #include <linux/kernel.h>
13 #include <linux/interrupt.h>
14 #include <linux/delay.h>
15 #include <linux/iopoll.h>
16 #include <linux/usb/otg.h>
17
18 #include "drd.h"
19 #include "core.h"
20
21 /**
22 * cdns_set_mode - change mode of OTG Core
23 * @cdns: pointer to context structure
24 * @mode: selected mode from cdns_role
25 *
26 * Returns 0 on success otherwise negative errno
27 */
cdns_set_mode(struct cdns * cdns,enum usb_dr_mode mode)28 static int cdns_set_mode(struct cdns *cdns, enum usb_dr_mode mode)
29 {
30 void __iomem *override_reg;
31 u32 reg;
32
33 switch (mode) {
34 case USB_DR_MODE_PERIPHERAL:
35 break;
36 case USB_DR_MODE_HOST:
37 break;
38 case USB_DR_MODE_OTG:
39 dev_dbg(cdns->dev, "Set controller to OTG mode\n");
40
41 if (cdns->version == CDNSP_CONTROLLER_V2)
42 override_reg = &cdns->otg_cdnsp_regs->override;
43 else if (cdns->version == CDNS3_CONTROLLER_V1)
44 override_reg = &cdns->otg_v1_regs->override;
45 else
46 override_reg = &cdns->otg_v0_regs->ctrl1;
47
48 reg = readl(override_reg);
49
50 if (cdns->version != CDNS3_CONTROLLER_V0)
51 reg |= OVERRIDE_IDPULLUP;
52 else
53 reg |= OVERRIDE_IDPULLUP_V0;
54
55 writel(reg, override_reg);
56
57 if (cdns->version == CDNS3_CONTROLLER_V1) {
58 /*
59 * Enable work around feature built into the
60 * controller to address issue with RX Sensitivity
61 * est (EL_17) for USB2 PHY. The issue only occures
62 * for 0x0002450D controller version.
63 */
64 if (cdns->phyrst_a_enable) {
65 reg = readl(&cdns->otg_v1_regs->phyrst_cfg);
66 reg |= PHYRST_CFG_PHYRST_A_ENABLE;
67 writel(reg, &cdns->otg_v1_regs->phyrst_cfg);
68 }
69 }
70
71 /*
72 * Hardware specification says: "ID_VALUE must be valid within
73 * 50ms after idpullup is set to '1" so driver must wait
74 * 50ms before reading this pin.
75 */
76 usleep_range(50000, 60000);
77 break;
78 default:
79 dev_err(cdns->dev, "Unsupported mode of operation %d\n", mode);
80 return -EINVAL;
81 }
82
83 return 0;
84 }
85
cdns_get_id(struct cdns * cdns)86 int cdns_get_id(struct cdns *cdns)
87 {
88 int id;
89
90 id = readl(&cdns->otg_regs->sts) & OTGSTS_ID_VALUE;
91 dev_dbg(cdns->dev, "OTG ID: %d", id);
92
93 return id;
94 }
95
cdns_get_vbus(struct cdns * cdns)96 int cdns_get_vbus(struct cdns *cdns)
97 {
98 int vbus;
99
100 vbus = !!(readl(&cdns->otg_regs->sts) & OTGSTS_VBUS_VALID);
101 dev_dbg(cdns->dev, "OTG VBUS: %d", vbus);
102
103 return vbus;
104 }
105
cdns_clear_vbus(struct cdns * cdns)106 void cdns_clear_vbus(struct cdns *cdns)
107 {
108 u32 reg;
109
110 if (cdns->version != CDNSP_CONTROLLER_V2)
111 return;
112
113 reg = readl(&cdns->otg_cdnsp_regs->override);
114 reg |= OVERRIDE_SESS_VLD_SEL;
115 writel(reg, &cdns->otg_cdnsp_regs->override);
116 }
117 EXPORT_SYMBOL_GPL(cdns_clear_vbus);
118
cdns_set_vbus(struct cdns * cdns)119 void cdns_set_vbus(struct cdns *cdns)
120 {
121 u32 reg;
122
123 if (cdns->version != CDNSP_CONTROLLER_V2)
124 return;
125
126 reg = readl(&cdns->otg_cdnsp_regs->override);
127 reg &= ~OVERRIDE_SESS_VLD_SEL;
128 writel(reg, &cdns->otg_cdnsp_regs->override);
129 }
130 EXPORT_SYMBOL_GPL(cdns_set_vbus);
131
cdns_is_host(struct cdns * cdns)132 bool cdns_is_host(struct cdns *cdns)
133 {
134 if (cdns->dr_mode == USB_DR_MODE_HOST)
135 return true;
136 else if (cdns_get_id(cdns) == CDNS3_ID_HOST)
137 return true;
138
139 return false;
140 }
141
cdns_is_device(struct cdns * cdns)142 bool cdns_is_device(struct cdns *cdns)
143 {
144 if (cdns->dr_mode == USB_DR_MODE_PERIPHERAL)
145 return true;
146 else if (cdns->dr_mode == USB_DR_MODE_OTG)
147 if (cdns_get_id(cdns) == CDNS3_ID_PERIPHERAL)
148 return true;
149
150 return false;
151 }
152
153 /**
154 * cdns_otg_disable_irq - Disable all OTG interrupts
155 * @cdns: Pointer to controller context structure
156 */
cdns_otg_disable_irq(struct cdns * cdns)157 static void cdns_otg_disable_irq(struct cdns *cdns)
158 {
159 writel(0, &cdns->otg_irq_regs->ien);
160 }
161
162 /**
163 * cdns_otg_enable_irq - enable id and sess_valid interrupts
164 * @cdns: Pointer to controller context structure
165 */
cdns_otg_enable_irq(struct cdns * cdns)166 static void cdns_otg_enable_irq(struct cdns *cdns)
167 {
168 writel(OTGIEN_ID_CHANGE_INT | OTGIEN_VBUSVALID_RISE_INT |
169 OTGIEN_VBUSVALID_FALL_INT, &cdns->otg_irq_regs->ien);
170 }
171
172 /**
173 * cdns_drd_host_on - start host.
174 * @cdns: Pointer to controller context structure.
175 *
176 * Returns 0 on success otherwise negative errno.
177 */
cdns_drd_host_on(struct cdns * cdns)178 int cdns_drd_host_on(struct cdns *cdns)
179 {
180 u32 val, ready_bit;
181 int ret;
182
183 /* Enable host mode. */
184 writel(OTGCMD_HOST_BUS_REQ | OTGCMD_OTG_DIS,
185 &cdns->otg_regs->cmd);
186
187 if (cdns->version == CDNSP_CONTROLLER_V2)
188 ready_bit = OTGSTS_CDNSP_XHCI_READY;
189 else
190 ready_bit = OTGSTS_CDNS3_XHCI_READY;
191
192 dev_dbg(cdns->dev, "Waiting till Host mode is turned on\n");
193 ret = readl_poll_timeout_atomic(&cdns->otg_regs->sts, val,
194 val & ready_bit, 1, 100000);
195
196 if (ret)
197 dev_err(cdns->dev, "timeout waiting for xhci_ready\n");
198
199 phy_set_mode(cdns->usb3_phy, PHY_MODE_USB_HOST);
200 return ret;
201 }
202
203 /**
204 * cdns_drd_host_off - stop host.
205 * @cdns: Pointer to controller context structure.
206 */
cdns_drd_host_off(struct cdns * cdns)207 void cdns_drd_host_off(struct cdns *cdns)
208 {
209 u32 val;
210
211 writel(OTGCMD_HOST_BUS_DROP | OTGCMD_DEV_BUS_DROP |
212 OTGCMD_DEV_POWER_OFF | OTGCMD_HOST_POWER_OFF,
213 &cdns->otg_regs->cmd);
214
215 /* Waiting till H_IDLE state.*/
216 readl_poll_timeout_atomic(&cdns->otg_regs->state, val,
217 !(val & OTGSTATE_HOST_STATE_MASK),
218 1, 2000000);
219 phy_set_mode(cdns->usb3_phy, PHY_MODE_INVALID);
220 }
221
222 /**
223 * cdns_drd_gadget_on - start gadget.
224 * @cdns: Pointer to controller context structure.
225 *
226 * Returns 0 on success otherwise negative errno
227 */
cdns_drd_gadget_on(struct cdns * cdns)228 int cdns_drd_gadget_on(struct cdns *cdns)
229 {
230 u32 reg = OTGCMD_OTG_DIS;
231 u32 ready_bit;
232 int ret, val;
233
234 /* switch OTG core */
235 writel(OTGCMD_DEV_BUS_REQ | reg, &cdns->otg_regs->cmd);
236
237 dev_dbg(cdns->dev, "Waiting till Device mode is turned on\n");
238
239 if (cdns->version == CDNSP_CONTROLLER_V2)
240 ready_bit = OTGSTS_CDNSP_DEV_READY;
241 else
242 ready_bit = OTGSTS_CDNS3_DEV_READY;
243
244 ret = readl_poll_timeout_atomic(&cdns->otg_regs->sts, val,
245 val & ready_bit, 1, 100000);
246 if (ret) {
247 dev_err(cdns->dev, "timeout waiting for dev_ready\n");
248 return ret;
249 }
250
251 phy_set_mode(cdns->usb3_phy, PHY_MODE_USB_DEVICE);
252 return 0;
253 }
254 EXPORT_SYMBOL_GPL(cdns_drd_gadget_on);
255
256 /**
257 * cdns_drd_gadget_off - stop gadget.
258 * @cdns: Pointer to controller context structure.
259 */
cdns_drd_gadget_off(struct cdns * cdns)260 void cdns_drd_gadget_off(struct cdns *cdns)
261 {
262 u32 val;
263
264 /*
265 * Driver should wait at least 10us after disabling Device
266 * before turning-off Device (DEV_BUS_DROP).
267 */
268 usleep_range(20, 30);
269 writel(OTGCMD_HOST_BUS_DROP | OTGCMD_DEV_BUS_DROP |
270 OTGCMD_DEV_POWER_OFF | OTGCMD_HOST_POWER_OFF,
271 &cdns->otg_regs->cmd);
272 /* Waiting till DEV_IDLE state.*/
273 readl_poll_timeout_atomic(&cdns->otg_regs->state, val,
274 !(val & OTGSTATE_DEV_STATE_MASK),
275 1, 2000000);
276 phy_set_mode(cdns->usb3_phy, PHY_MODE_INVALID);
277 }
278 EXPORT_SYMBOL_GPL(cdns_drd_gadget_off);
279
280 /**
281 * cdns_init_otg_mode - initialize drd controller
282 * @cdns: Pointer to controller context structure
283 *
284 * Returns 0 on success otherwise negative errno
285 */
cdns_init_otg_mode(struct cdns * cdns)286 static int cdns_init_otg_mode(struct cdns *cdns)
287 {
288 int ret;
289
290 cdns_otg_disable_irq(cdns);
291 /* clear all interrupts */
292 writel(~0, &cdns->otg_irq_regs->ivect);
293
294 ret = cdns_set_mode(cdns, USB_DR_MODE_OTG);
295 if (ret)
296 return ret;
297
298 cdns_otg_enable_irq(cdns);
299
300 return 0;
301 }
302
303 /**
304 * cdns_drd_update_mode - initialize mode of operation
305 * @cdns: Pointer to controller context structure
306 *
307 * Returns 0 on success otherwise negative errno
308 */
cdns_drd_update_mode(struct cdns * cdns)309 int cdns_drd_update_mode(struct cdns *cdns)
310 {
311 int ret;
312
313 switch (cdns->dr_mode) {
314 case USB_DR_MODE_PERIPHERAL:
315 ret = cdns_set_mode(cdns, USB_DR_MODE_PERIPHERAL);
316 break;
317 case USB_DR_MODE_HOST:
318 ret = cdns_set_mode(cdns, USB_DR_MODE_HOST);
319 break;
320 case USB_DR_MODE_OTG:
321 ret = cdns_init_otg_mode(cdns);
322 break;
323 default:
324 dev_err(cdns->dev, "Unsupported mode of operation %d\n",
325 cdns->dr_mode);
326 return -EINVAL;
327 }
328
329 return ret;
330 }
331
cdns_drd_thread_irq(int irq,void * data)332 static irqreturn_t cdns_drd_thread_irq(int irq, void *data)
333 {
334 struct cdns *cdns = data;
335
336 cdns_hw_role_switch(cdns);
337
338 return IRQ_HANDLED;
339 }
340
341 /**
342 * cdns_drd_irq - interrupt handler for OTG events
343 *
344 * @irq: irq number for cdns core device
345 * @data: structure of cdns
346 *
347 * Returns IRQ_HANDLED or IRQ_NONE
348 */
cdns_drd_irq(int irq,void * data)349 static irqreturn_t cdns_drd_irq(int irq, void *data)
350 {
351 irqreturn_t ret = IRQ_NONE;
352 struct cdns *cdns = data;
353 u32 reg;
354
355 if (cdns->dr_mode != USB_DR_MODE_OTG)
356 return IRQ_NONE;
357
358 if (cdns->in_lpm)
359 return ret;
360
361 reg = readl(&cdns->otg_irq_regs->ivect);
362
363 if (!reg)
364 return IRQ_NONE;
365
366 if (reg & OTGIEN_ID_CHANGE_INT) {
367 dev_dbg(cdns->dev, "OTG IRQ: new ID: %d\n",
368 cdns_get_id(cdns));
369
370 ret = IRQ_WAKE_THREAD;
371 }
372
373 if (reg & (OTGIEN_VBUSVALID_RISE_INT | OTGIEN_VBUSVALID_FALL_INT)) {
374 dev_dbg(cdns->dev, "OTG IRQ: new VBUS: %d\n",
375 cdns_get_vbus(cdns));
376
377 ret = IRQ_WAKE_THREAD;
378 }
379
380 writel(~0, &cdns->otg_irq_regs->ivect);
381 return ret;
382 }
383
cdns_drd_init(struct cdns * cdns)384 int cdns_drd_init(struct cdns *cdns)
385 {
386 void __iomem *regs;
387 u32 state;
388 int ret;
389
390 regs = devm_ioremap_resource(cdns->dev, &cdns->otg_res);
391 if (IS_ERR(regs))
392 return PTR_ERR(regs);
393
394 /* Detection of DRD version. Controller has been released
395 * in three versions. All are very similar and are software compatible,
396 * but they have same changes in register maps.
397 * The first register in oldest version is command register and it's
398 * read only. Driver should read 0 from it. On the other hand, in v1
399 * and v2 the first register contains device ID number which is not
400 * set to 0. Driver uses this fact to detect the proper version of
401 * controller.
402 */
403 cdns->otg_v0_regs = regs;
404 if (!readl(&cdns->otg_v0_regs->cmd)) {
405 cdns->version = CDNS3_CONTROLLER_V0;
406 cdns->otg_v1_regs = NULL;
407 cdns->otg_cdnsp_regs = NULL;
408 cdns->otg_regs = regs;
409 cdns->otg_irq_regs = (struct cdns_otg_irq_regs __iomem *)
410 &cdns->otg_v0_regs->ien;
411 writel(1, &cdns->otg_v0_regs->simulate);
412 dev_dbg(cdns->dev, "DRD version v0 (%08x)\n",
413 readl(&cdns->otg_v0_regs->version));
414 } else {
415 cdns->otg_v0_regs = NULL;
416 cdns->otg_v1_regs = regs;
417 cdns->otg_cdnsp_regs = regs;
418
419 cdns->otg_regs = (void __iomem *)&cdns->otg_v1_regs->cmd;
420
421 if (readl(&cdns->otg_cdnsp_regs->did) == OTG_CDNSP_DID) {
422 cdns->otg_irq_regs = (struct cdns_otg_irq_regs __iomem *)
423 &cdns->otg_cdnsp_regs->ien;
424 cdns->version = CDNSP_CONTROLLER_V2;
425 } else {
426 cdns->otg_irq_regs = (struct cdns_otg_irq_regs __iomem *)
427 &cdns->otg_v1_regs->ien;
428 writel(1, &cdns->otg_v1_regs->simulate);
429 cdns->version = CDNS3_CONTROLLER_V1;
430 }
431
432 dev_dbg(cdns->dev, "DRD version v1 (ID: %08x, rev: %08x)\n",
433 readl(&cdns->otg_v1_regs->did),
434 readl(&cdns->otg_v1_regs->rid));
435 }
436
437 state = OTGSTS_STRAP(readl(&cdns->otg_regs->sts));
438
439 /* Update dr_mode according to STRAP configuration. */
440 cdns->dr_mode = USB_DR_MODE_OTG;
441
442 if ((cdns->version == CDNSP_CONTROLLER_V2 &&
443 state == OTGSTS_CDNSP_STRAP_HOST) ||
444 (cdns->version != CDNSP_CONTROLLER_V2 &&
445 state == OTGSTS_STRAP_HOST)) {
446 dev_dbg(cdns->dev, "Controller strapped to HOST\n");
447 cdns->dr_mode = USB_DR_MODE_HOST;
448 } else if ((cdns->version == CDNSP_CONTROLLER_V2 &&
449 state == OTGSTS_CDNSP_STRAP_GADGET) ||
450 (cdns->version != CDNSP_CONTROLLER_V2 &&
451 state == OTGSTS_STRAP_GADGET)) {
452 dev_dbg(cdns->dev, "Controller strapped to PERIPHERAL\n");
453 cdns->dr_mode = USB_DR_MODE_PERIPHERAL;
454 }
455
456 ret = devm_request_threaded_irq(cdns->dev, cdns->otg_irq,
457 cdns_drd_irq,
458 cdns_drd_thread_irq,
459 IRQF_SHARED,
460 dev_name(cdns->dev), cdns);
461 if (ret) {
462 dev_err(cdns->dev, "couldn't get otg_irq\n");
463 return ret;
464 }
465
466 state = readl(&cdns->otg_regs->sts);
467 if (OTGSTS_OTG_NRDY(state)) {
468 dev_err(cdns->dev, "Cadence USB3 OTG device not ready\n");
469 return -ENODEV;
470 }
471
472 return 0;
473 }
474
cdns_drd_exit(struct cdns * cdns)475 int cdns_drd_exit(struct cdns *cdns)
476 {
477 cdns_otg_disable_irq(cdns);
478
479 return 0;
480 }
481
482
483 /* Indicate the cdns3 core was power lost before */
cdns_power_is_lost(struct cdns * cdns)484 bool cdns_power_is_lost(struct cdns *cdns)
485 {
486 if (cdns->version == CDNS3_CONTROLLER_V0) {
487 if (!(readl(&cdns->otg_v0_regs->simulate) & BIT(0)))
488 return true;
489 } else {
490 if (!(readl(&cdns->otg_v1_regs->simulate) & BIT(0)))
491 return true;
492 }
493 return false;
494 }
495 EXPORT_SYMBOL_GPL(cdns_power_is_lost);
496
