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 <dm.h>
14 #include <dm/device_compat.h>
15 #include <linux/delay.h>
16 #include <linux/iopoll.h>
17 #include <linux/kernel.h>
18 #include <linux/usb/otg.h>
19
20 #include "gadget.h"
21 #include "drd.h"
22 #include "core.h"
23
24 #define readl_poll_timeout_atomic readl_poll_timeout
25 #define usleep_range(a, b) udelay((b))
26 /**
27 * cdns3_set_mode - change mode of OTG Core
28 * @cdns: pointer to context structure
29 * @mode: selected mode from cdns_role
30 *
31 * Returns 0 on success otherwise negative errno
32 */
cdns3_set_mode(struct cdns3 * cdns,enum usb_dr_mode mode)33 int cdns3_set_mode(struct cdns3 *cdns, enum usb_dr_mode mode)
34 {
35 int ret = 0;
36 u32 reg;
37
38 switch (mode) {
39 case USB_DR_MODE_PERIPHERAL:
40 break;
41 case USB_DR_MODE_HOST:
42 break;
43 case USB_DR_MODE_OTG:
44 dev_dbg(cdns->dev, "Set controller to OTG mode\n");
45 if (cdns->version == CDNS3_CONTROLLER_V1) {
46 reg = readl(&cdns->otg_v1_regs->override);
47 reg |= OVERRIDE_IDPULLUP;
48 writel(reg, &cdns->otg_v1_regs->override);
49 } else {
50 reg = readl(&cdns->otg_v0_regs->ctrl1);
51 reg |= OVERRIDE_IDPULLUP_V0;
52 writel(reg, &cdns->otg_v0_regs->ctrl1);
53 }
54
55 /*
56 * Hardware specification says: "ID_VALUE must be valid within
57 * 50ms after idpullup is set to '1" so driver must wait
58 * 50ms before reading this pin.
59 */
60 usleep_range(50000, 60000);
61 break;
62 default:
63 dev_err(cdns->dev, "Unsupported mode of operation %d\n", mode);
64 return -EINVAL;
65 }
66
67 return ret;
68 }
69
cdns3_get_id(struct cdns3 * cdns)70 int cdns3_get_id(struct cdns3 *cdns)
71 {
72 int id;
73
74 id = readl(&cdns->otg_regs->sts) & OTGSTS_ID_VALUE;
75 dev_dbg(cdns->dev, "OTG ID: %d", id);
76
77 return id;
78 }
79
cdns3_get_vbus(struct cdns3 * cdns)80 int cdns3_get_vbus(struct cdns3 *cdns)
81 {
82 int vbus;
83
84 vbus = !!(readl(&cdns->otg_regs->sts) & OTGSTS_VBUS_VALID);
85 dev_dbg(cdns->dev, "OTG VBUS: %d", vbus);
86
87 return vbus;
88 }
89
cdns3_is_host(struct cdns3 * cdns)90 int cdns3_is_host(struct cdns3 *cdns)
91 {
92 if (cdns->dr_mode == USB_DR_MODE_HOST)
93 return 1;
94 else if (!cdns3_get_id(cdns))
95 return 1;
96
97 return 0;
98 }
99
cdns3_is_device(struct cdns3 * cdns)100 int cdns3_is_device(struct cdns3 *cdns)
101 {
102 if (cdns->dr_mode == USB_DR_MODE_PERIPHERAL)
103 return 1;
104 else if (cdns->dr_mode == USB_DR_MODE_OTG)
105 if (cdns3_get_id(cdns))
106 return 1;
107
108 return 0;
109 }
110
111 /**
112 * cdns3_drd_switch_host - start/stop host
113 * @cdns: Pointer to controller context structure
114 * @on: 1 for start, 0 for stop
115 *
116 * Returns 0 on success otherwise negative errno
117 */
cdns3_drd_switch_host(struct cdns3 * cdns,int on)118 int cdns3_drd_switch_host(struct cdns3 *cdns, int on)
119 {
120 int ret, val;
121 u32 reg = OTGCMD_OTG_DIS;
122
123 /* switch OTG core */
124 if (on) {
125 writel(OTGCMD_HOST_BUS_REQ | reg, &cdns->otg_regs->cmd);
126
127 dev_dbg(cdns->dev, "Waiting till Host mode is turned on\n");
128 ret = readl_poll_timeout_atomic(&cdns->otg_regs->sts, val,
129 val & OTGSTS_XHCI_READY,
130 100000);
131 if (ret) {
132 dev_err(cdns->dev, "timeout waiting for xhci_ready\n");
133 return ret;
134 }
135 } else {
136 writel(OTGCMD_HOST_BUS_DROP | OTGCMD_DEV_BUS_DROP |
137 OTGCMD_DEV_POWER_OFF | OTGCMD_HOST_POWER_OFF,
138 &cdns->otg_regs->cmd);
139 /* Waiting till H_IDLE state.*/
140 readl_poll_timeout_atomic(&cdns->otg_regs->state, val,
141 !(val & OTGSTATE_HOST_STATE_MASK),
142 2000000);
143 }
144
145 return 0;
146 }
147
148 /**
149 * cdns3_drd_switch_gadget - start/stop gadget
150 * @cdns: Pointer to controller context structure
151 * @on: 1 for start, 0 for stop
152 *
153 * Returns 0 on success otherwise negative errno
154 */
cdns3_drd_switch_gadget(struct cdns3 * cdns,int on)155 int cdns3_drd_switch_gadget(struct cdns3 *cdns, int on)
156 {
157 int ret, val;
158 u32 reg = OTGCMD_OTG_DIS;
159
160 /* switch OTG core */
161 if (on) {
162 writel(OTGCMD_DEV_BUS_REQ | reg, &cdns->otg_regs->cmd);
163
164 dev_dbg(cdns->dev, "Waiting till Device mode is turned on\n");
165
166 ret = readl_poll_timeout_atomic(&cdns->otg_regs->sts, val,
167 val & OTGSTS_DEV_READY,
168 100000);
169 if (ret) {
170 dev_err(cdns->dev, "timeout waiting for dev_ready\n");
171 return ret;
172 }
173 } else {
174 /*
175 * driver should wait at least 10us after disabling Device
176 * before turning-off Device (DEV_BUS_DROP)
177 */
178 usleep_range(20, 30);
179 writel(OTGCMD_HOST_BUS_DROP | OTGCMD_DEV_BUS_DROP |
180 OTGCMD_DEV_POWER_OFF | OTGCMD_HOST_POWER_OFF,
181 &cdns->otg_regs->cmd);
182 /* Waiting till DEV_IDLE state.*/
183 readl_poll_timeout_atomic(&cdns->otg_regs->state, val,
184 !(val & OTGSTATE_DEV_STATE_MASK),
185 2000000);
186 }
187
188 return 0;
189 }
190
191 /**
192 * cdns3_init_otg_mode - initialize drd controller
193 * @cdns: Pointer to controller context structure
194 *
195 * Returns 0 on success otherwise negative errno
196 */
cdns3_init_otg_mode(struct cdns3 * cdns)197 static int cdns3_init_otg_mode(struct cdns3 *cdns)
198 {
199 int ret = 0;
200
201 /* clear all interrupts */
202 writel(~0, &cdns->otg_regs->ivect);
203
204 ret = cdns3_set_mode(cdns, USB_DR_MODE_OTG);
205 if (ret)
206 return ret;
207
208 return ret;
209 }
210
211 /**
212 * cdns3_drd_update_mode - initialize mode of operation
213 * @cdns: Pointer to controller context structure
214 *
215 * Returns 0 on success otherwise negative errno
216 */
cdns3_drd_update_mode(struct cdns3 * cdns)217 int cdns3_drd_update_mode(struct cdns3 *cdns)
218 {
219 int ret = 0;
220
221 switch (cdns->dr_mode) {
222 case USB_DR_MODE_PERIPHERAL:
223 ret = cdns3_set_mode(cdns, USB_DR_MODE_PERIPHERAL);
224 break;
225 case USB_DR_MODE_HOST:
226 ret = cdns3_set_mode(cdns, USB_DR_MODE_HOST);
227 break;
228 case USB_DR_MODE_OTG:
229 ret = cdns3_init_otg_mode(cdns);
230 break;
231 default:
232 dev_err(cdns->dev, "Unsupported mode of operation %d\n",
233 cdns->dr_mode);
234 return -EINVAL;
235 }
236
237 return ret;
238 }
239
cdns3_drd_init(struct cdns3 * cdns)240 int cdns3_drd_init(struct cdns3 *cdns)
241 {
242 void __iomem *regs;
243 int ret = 0;
244 u32 state;
245
246 regs = dev_remap_addr_name(cdns->dev, "otg");
247 if (!regs)
248 return -EINVAL;
249
250 /* Detection of DRD version. Controller has been released
251 * in two versions. Both are similar, but they have same changes
252 * in register maps.
253 * The first register in old version is command register and it's read
254 * only, so driver should read 0 from it. On the other hand, in v1
255 * the first register contains device ID number which is not set to 0.
256 * Driver uses this fact to detect the proper version of
257 * controller.
258 */
259 cdns->otg_v0_regs = regs;
260 if (!readl(&cdns->otg_v0_regs->cmd)) {
261 cdns->version = CDNS3_CONTROLLER_V0;
262 cdns->otg_v1_regs = NULL;
263 cdns->otg_regs = regs;
264 writel(1, &cdns->otg_v0_regs->simulate);
265 dev_info(cdns->dev, "DRD version v0 (%08x)\n",
266 readl(&cdns->otg_v0_regs->version));
267 } else {
268 cdns->otg_v0_regs = NULL;
269 cdns->otg_v1_regs = regs;
270 cdns->otg_regs = (void *)&cdns->otg_v1_regs->cmd;
271 cdns->version = CDNS3_CONTROLLER_V1;
272 writel(1, &cdns->otg_v1_regs->simulate);
273 dev_info(cdns->dev, "DRD version v1 (ID: %08x, rev: %08x)\n",
274 readl(&cdns->otg_v1_regs->did),
275 readl(&cdns->otg_v1_regs->rid));
276 }
277
278 state = OTGSTS_STRAP(readl(&cdns->otg_regs->sts));
279
280 /* Update dr_mode according to STRAP configuration. */
281 cdns->dr_mode = USB_DR_MODE_OTG;
282 if (state == OTGSTS_STRAP_HOST) {
283 dev_dbg(cdns->dev, "Controller strapped to HOST\n");
284 cdns->dr_mode = USB_DR_MODE_HOST;
285 } else if (state == OTGSTS_STRAP_GADGET) {
286 dev_dbg(cdns->dev, "Controller strapped to PERIPHERAL\n");
287 cdns->dr_mode = USB_DR_MODE_PERIPHERAL;
288 }
289
290 state = readl(&cdns->otg_regs->sts);
291 if (OTGSTS_OTG_NRDY(state) != 0) {
292 dev_err(cdns->dev, "Cadence USB3 OTG device not ready\n");
293 return -ENODEV;
294 }
295
296 return ret;
297 }
298
cdns3_drd_exit(struct cdns3 * cdns)299 int cdns3_drd_exit(struct cdns3 *cdns)
300 {
301 return 0;
302 }
303