1 // SPDX-License-Identifier: BSD-3-Clause
2 /*
3  * Copyright (c) 2020, MIPI Alliance, Inc.
4  *
5  * Author: Nicolas Pitre <npitre@baylibre.com>
6  *
7  * Core driver code with main interface to the I3C subsystem.
8  */
9 
10 #include <linux/bitfield.h>
11 #include <linux/device.h>
12 #include <linux/errno.h>
13 #include <linux/i3c/master.h>
14 #include <linux/interrupt.h>
15 #include <linux/io.h>
16 #include <linux/iopoll.h>
17 #include <linux/module.h>
18 #include <linux/platform_device.h>
19 
20 #include "hci.h"
21 #include "ext_caps.h"
22 #include "cmd.h"
23 #include "dat.h"
24 
25 
26 /*
27  * Host Controller Capabilities and Operation Registers
28  */
29 
30 #define reg_read(r)		readl(hci->base_regs + (r))
31 #define reg_write(r, v)		writel(v, hci->base_regs + (r))
32 #define reg_set(r, v)		reg_write(r, reg_read(r) | (v))
33 #define reg_clear(r, v)		reg_write(r, reg_read(r) & ~(v))
34 
35 #define HCI_VERSION			0x00	/* HCI Version (in BCD) */
36 
37 #define HC_CONTROL			0x04
38 #define HC_CONTROL_BUS_ENABLE		BIT(31)
39 #define HC_CONTROL_RESUME		BIT(30)
40 #define HC_CONTROL_ABORT		BIT(29)
41 #define HC_CONTROL_HALT_ON_CMD_TIMEOUT	BIT(12)
42 #define HC_CONTROL_HOT_JOIN_CTRL	BIT(8)	/* Hot-Join ACK/NACK Control */
43 #define HC_CONTROL_I2C_TARGET_PRESENT	BIT(7)
44 #define HC_CONTROL_PIO_MODE		BIT(6)	/* DMA/PIO Mode Selector */
45 #define HC_CONTROL_DATA_BIG_ENDIAN	BIT(4)
46 #define HC_CONTROL_IBA_INCLUDE		BIT(0)	/* Include I3C Broadcast Address */
47 
48 #define MASTER_DEVICE_ADDR		0x08	/* Master Device Address */
49 #define MASTER_DYNAMIC_ADDR_VALID	BIT(31)	/* Dynamic Address is Valid */
50 #define MASTER_DYNAMIC_ADDR(v)		FIELD_PREP(GENMASK(22, 16), v)
51 
52 #define HC_CAPABILITIES			0x0c
53 #define HC_CAP_SG_DC_EN			BIT(30)
54 #define HC_CAP_SG_IBI_EN		BIT(29)
55 #define HC_CAP_SG_CR_EN			BIT(28)
56 #define HC_CAP_MAX_DATA_LENGTH		GENMASK(24, 22)
57 #define HC_CAP_CMD_SIZE			GENMASK(21, 20)
58 #define HC_CAP_DIRECT_COMMANDS_EN	BIT(18)
59 #define HC_CAP_MULTI_LANE_EN		BIT(15)
60 #define HC_CAP_CMD_CCC_DEFBYTE		BIT(10)
61 #define HC_CAP_HDR_BT_EN		BIT(8)
62 #define HC_CAP_HDR_TS_EN		BIT(7)
63 #define HC_CAP_HDR_DDR_EN		BIT(6)
64 #define HC_CAP_NON_CURRENT_MASTER_CAP	BIT(5)	/* master handoff capable */
65 #define HC_CAP_DATA_BYTE_CFG_EN		BIT(4)	/* endian selection possible */
66 #define HC_CAP_AUTO_COMMAND		BIT(3)
67 #define HC_CAP_COMBO_COMMAND		BIT(2)
68 
69 #define RESET_CONTROL			0x10
70 #define BUS_RESET			BIT(31)
71 #define BUS_RESET_TYPE			GENMASK(30, 29)
72 #define IBI_QUEUE_RST			BIT(5)
73 #define RX_FIFO_RST			BIT(4)
74 #define TX_FIFO_RST			BIT(3)
75 #define RESP_QUEUE_RST			BIT(2)
76 #define CMD_QUEUE_RST			BIT(1)
77 #define SOFT_RST			BIT(0)	/* Core Reset */
78 
79 #define PRESENT_STATE			0x14
80 #define STATE_CURRENT_MASTER		BIT(2)
81 
82 #define INTR_STATUS			0x20
83 #define INTR_STATUS_ENABLE		0x24
84 #define INTR_SIGNAL_ENABLE		0x28
85 #define INTR_FORCE			0x2c
86 #define INTR_HC_CMD_SEQ_UFLOW_STAT	BIT(12)	/* Cmd Sequence Underflow */
87 #define INTR_HC_RESET_CANCEL		BIT(11)	/* HC Cancelled Reset */
88 #define INTR_HC_INTERNAL_ERR		BIT(10)	/* HC Internal Error */
89 #define INTR_HC_PIO			BIT(8)	/* cascaded PIO interrupt */
90 #define INTR_HC_RINGS			GENMASK(7, 0)
91 
92 #define DAT_SECTION			0x30	/* Device Address Table */
93 #define DAT_ENTRY_SIZE			GENMASK(31, 28)
94 #define DAT_TABLE_SIZE			GENMASK(18, 12)
95 #define DAT_TABLE_OFFSET		GENMASK(11, 0)
96 
97 #define DCT_SECTION			0x34	/* Device Characteristics Table */
98 #define DCT_ENTRY_SIZE			GENMASK(31, 28)
99 #define DCT_TABLE_INDEX			GENMASK(23, 19)
100 #define DCT_TABLE_SIZE			GENMASK(18, 12)
101 #define DCT_TABLE_OFFSET		GENMASK(11, 0)
102 
103 #define RING_HEADERS_SECTION		0x38
104 #define RING_HEADERS_OFFSET		GENMASK(15, 0)
105 
106 #define PIO_SECTION			0x3c
107 #define PIO_REGS_OFFSET			GENMASK(15, 0)	/* PIO Offset */
108 
109 #define EXT_CAPS_SECTION		0x40
110 #define EXT_CAPS_OFFSET			GENMASK(15, 0)
111 
112 #define IBI_NOTIFY_CTRL			0x58	/* IBI Notify Control */
113 #define IBI_NOTIFY_SIR_REJECTED		BIT(3)	/* Rejected Target Interrupt Request */
114 #define IBI_NOTIFY_MR_REJECTED		BIT(1)	/* Rejected Master Request Control */
115 #define IBI_NOTIFY_HJ_REJECTED		BIT(0)	/* Rejected Hot-Join Control */
116 
117 #define DEV_CTX_BASE_LO			0x60
118 #define DEV_CTX_BASE_HI			0x64
119 
120 
121 static inline struct i3c_hci *to_i3c_hci(struct i3c_master_controller *m)
122 {
123 	return container_of(m, struct i3c_hci, master);
124 }
125 
126 static int i3c_hci_bus_init(struct i3c_master_controller *m)
127 {
128 	struct i3c_hci *hci = to_i3c_hci(m);
129 	struct i3c_device_info info;
130 	int ret;
131 
132 	DBG("");
133 
134 	if (hci->cmd == &mipi_i3c_hci_cmd_v1) {
135 		ret = mipi_i3c_hci_dat_v1.init(hci);
136 		if (ret)
137 			return ret;
138 	}
139 
140 	ret = i3c_master_get_free_addr(m, 0);
141 	if (ret < 0)
142 		return ret;
143 	reg_write(MASTER_DEVICE_ADDR,
144 		  MASTER_DYNAMIC_ADDR(ret) | MASTER_DYNAMIC_ADDR_VALID);
145 	memset(&info, 0, sizeof(info));
146 	info.dyn_addr = ret;
147 	ret = i3c_master_set_info(m, &info);
148 	if (ret)
149 		return ret;
150 
151 	ret = hci->io->init(hci);
152 	if (ret)
153 		return ret;
154 
155 	reg_set(HC_CONTROL, HC_CONTROL_BUS_ENABLE);
156 	DBG("HC_CONTROL = %#x", reg_read(HC_CONTROL));
157 
158 	return 0;
159 }
160 
161 static void i3c_hci_bus_cleanup(struct i3c_master_controller *m)
162 {
163 	struct i3c_hci *hci = to_i3c_hci(m);
164 
165 	DBG("");
166 
167 	reg_clear(HC_CONTROL, HC_CONTROL_BUS_ENABLE);
168 	hci->io->cleanup(hci);
169 	if (hci->cmd == &mipi_i3c_hci_cmd_v1)
170 		mipi_i3c_hci_dat_v1.cleanup(hci);
171 }
172 
173 void mipi_i3c_hci_resume(struct i3c_hci *hci)
174 {
175 	/* the HC_CONTROL_RESUME bit is R/W1C so just read and write back */
176 	reg_write(HC_CONTROL, reg_read(HC_CONTROL));
177 }
178 
179 /* located here rather than pio.c because needed bits are in core reg space */
180 void mipi_i3c_hci_pio_reset(struct i3c_hci *hci)
181 {
182 	reg_write(RESET_CONTROL, RX_FIFO_RST | TX_FIFO_RST | RESP_QUEUE_RST);
183 }
184 
185 /* located here rather than dct.c because needed bits are in core reg space */
186 void mipi_i3c_hci_dct_index_reset(struct i3c_hci *hci)
187 {
188 	reg_write(DCT_SECTION, FIELD_PREP(DCT_TABLE_INDEX, 0));
189 }
190 
191 static int i3c_hci_send_ccc_cmd(struct i3c_master_controller *m,
192 				struct i3c_ccc_cmd *ccc)
193 {
194 	struct i3c_hci *hci = to_i3c_hci(m);
195 	struct hci_xfer *xfer;
196 	bool raw = !!(hci->quirks & HCI_QUIRK_RAW_CCC);
197 	bool prefixed = raw && !!(ccc->id & I3C_CCC_DIRECT);
198 	unsigned int nxfers = ccc->ndests + prefixed;
199 	DECLARE_COMPLETION_ONSTACK(done);
200 	int i, last, ret = 0;
201 
202 	DBG("cmd=%#x rnw=%d ndests=%d data[0].len=%d",
203 	    ccc->id, ccc->rnw, ccc->ndests, ccc->dests[0].payload.len);
204 
205 	xfer = hci_alloc_xfer(nxfers);
206 	if (!xfer)
207 		return -ENOMEM;
208 
209 	if (prefixed) {
210 		xfer->data = NULL;
211 		xfer->data_len = 0;
212 		xfer->rnw = false;
213 		hci->cmd->prep_ccc(hci, xfer, I3C_BROADCAST_ADDR,
214 				   ccc->id, true);
215 		xfer++;
216 	}
217 
218 	for (i = 0; i < nxfers - prefixed; i++) {
219 		xfer[i].data = ccc->dests[i].payload.data;
220 		xfer[i].data_len = ccc->dests[i].payload.len;
221 		xfer[i].rnw = ccc->rnw;
222 		ret = hci->cmd->prep_ccc(hci, &xfer[i], ccc->dests[i].addr,
223 					 ccc->id, raw);
224 		if (ret)
225 			goto out;
226 		xfer[i].cmd_desc[0] |= CMD_0_ROC;
227 	}
228 	last = i - 1;
229 	xfer[last].cmd_desc[0] |= CMD_0_TOC;
230 	xfer[last].completion = &done;
231 
232 	if (prefixed)
233 		xfer--;
234 
235 	ret = hci->io->queue_xfer(hci, xfer, nxfers);
236 	if (ret)
237 		goto out;
238 	if (!wait_for_completion_timeout(&done, HZ) &&
239 	    hci->io->dequeue_xfer(hci, xfer, nxfers)) {
240 		ret = -ETIME;
241 		goto out;
242 	}
243 	for (i = prefixed; i < nxfers; i++) {
244 		if (ccc->rnw)
245 			ccc->dests[i - prefixed].payload.len =
246 				RESP_DATA_LENGTH(xfer[i].response);
247 		if (RESP_STATUS(xfer[i].response) != RESP_SUCCESS) {
248 			ret = -EIO;
249 			goto out;
250 		}
251 	}
252 
253 	if (ccc->rnw)
254 		DBG("got: %*ph",
255 		    ccc->dests[0].payload.len, ccc->dests[0].payload.data);
256 
257 out:
258 	hci_free_xfer(xfer, nxfers);
259 	return ret;
260 }
261 
262 static int i3c_hci_daa(struct i3c_master_controller *m)
263 {
264 	struct i3c_hci *hci = to_i3c_hci(m);
265 
266 	DBG("");
267 
268 	return hci->cmd->perform_daa(hci);
269 }
270 
271 static int i3c_hci_priv_xfers(struct i3c_dev_desc *dev,
272 			      struct i3c_priv_xfer *i3c_xfers,
273 			      int nxfers)
274 {
275 	struct i3c_master_controller *m = i3c_dev_get_master(dev);
276 	struct i3c_hci *hci = to_i3c_hci(m);
277 	struct hci_xfer *xfer;
278 	DECLARE_COMPLETION_ONSTACK(done);
279 	unsigned int size_limit;
280 	int i, last, ret = 0;
281 
282 	DBG("nxfers = %d", nxfers);
283 
284 	xfer = hci_alloc_xfer(nxfers);
285 	if (!xfer)
286 		return -ENOMEM;
287 
288 	size_limit = 1U << (16 + FIELD_GET(HC_CAP_MAX_DATA_LENGTH, hci->caps));
289 
290 	for (i = 0; i < nxfers; i++) {
291 		xfer[i].data_len = i3c_xfers[i].len;
292 		ret = -EFBIG;
293 		if (xfer[i].data_len >= size_limit)
294 			goto out;
295 		xfer[i].rnw = i3c_xfers[i].rnw;
296 		if (i3c_xfers[i].rnw) {
297 			xfer[i].data = i3c_xfers[i].data.in;
298 		} else {
299 			/* silence the const qualifier warning with a cast */
300 			xfer[i].data = (void *) i3c_xfers[i].data.out;
301 		}
302 		hci->cmd->prep_i3c_xfer(hci, dev, &xfer[i]);
303 		xfer[i].cmd_desc[0] |= CMD_0_ROC;
304 	}
305 	last = i - 1;
306 	xfer[last].cmd_desc[0] |= CMD_0_TOC;
307 	xfer[last].completion = &done;
308 
309 	ret = hci->io->queue_xfer(hci, xfer, nxfers);
310 	if (ret)
311 		goto out;
312 	if (!wait_for_completion_timeout(&done, HZ) &&
313 	    hci->io->dequeue_xfer(hci, xfer, nxfers)) {
314 		ret = -ETIME;
315 		goto out;
316 	}
317 	for (i = 0; i < nxfers; i++) {
318 		if (i3c_xfers[i].rnw)
319 			i3c_xfers[i].len = RESP_DATA_LENGTH(xfer[i].response);
320 		if (RESP_STATUS(xfer[i].response) != RESP_SUCCESS) {
321 			ret = -EIO;
322 			goto out;
323 		}
324 	}
325 
326 out:
327 	hci_free_xfer(xfer, nxfers);
328 	return ret;
329 }
330 
331 static int i3c_hci_i2c_xfers(struct i2c_dev_desc *dev,
332 			     const struct i2c_msg *i2c_xfers, int nxfers)
333 {
334 	struct i3c_master_controller *m = i2c_dev_get_master(dev);
335 	struct i3c_hci *hci = to_i3c_hci(m);
336 	struct hci_xfer *xfer;
337 	DECLARE_COMPLETION_ONSTACK(done);
338 	int i, last, ret = 0;
339 
340 	DBG("nxfers = %d", nxfers);
341 
342 	xfer = hci_alloc_xfer(nxfers);
343 	if (!xfer)
344 		return -ENOMEM;
345 
346 	for (i = 0; i < nxfers; i++) {
347 		xfer[i].data = i2c_xfers[i].buf;
348 		xfer[i].data_len = i2c_xfers[i].len;
349 		xfer[i].rnw = i2c_xfers[i].flags & I2C_M_RD;
350 		hci->cmd->prep_i2c_xfer(hci, dev, &xfer[i]);
351 		xfer[i].cmd_desc[0] |= CMD_0_ROC;
352 	}
353 	last = i - 1;
354 	xfer[last].cmd_desc[0] |= CMD_0_TOC;
355 	xfer[last].completion = &done;
356 
357 	ret = hci->io->queue_xfer(hci, xfer, nxfers);
358 	if (ret)
359 		goto out;
360 	if (!wait_for_completion_timeout(&done, HZ) &&
361 	    hci->io->dequeue_xfer(hci, xfer, nxfers)) {
362 		ret = -ETIME;
363 		goto out;
364 	}
365 	for (i = 0; i < nxfers; i++) {
366 		if (RESP_STATUS(xfer[i].response) != RESP_SUCCESS) {
367 			ret = -EIO;
368 			goto out;
369 		}
370 	}
371 
372 out:
373 	hci_free_xfer(xfer, nxfers);
374 	return ret;
375 }
376 
377 static int i3c_hci_attach_i3c_dev(struct i3c_dev_desc *dev)
378 {
379 	struct i3c_master_controller *m = i3c_dev_get_master(dev);
380 	struct i3c_hci *hci = to_i3c_hci(m);
381 	struct i3c_hci_dev_data *dev_data;
382 	int ret;
383 
384 	DBG("");
385 
386 	dev_data = kzalloc(sizeof(*dev_data), GFP_KERNEL);
387 	if (!dev_data)
388 		return -ENOMEM;
389 	if (hci->cmd == &mipi_i3c_hci_cmd_v1) {
390 		ret = mipi_i3c_hci_dat_v1.alloc_entry(hci);
391 		if (ret < 0) {
392 			kfree(dev_data);
393 			return ret;
394 		}
395 		mipi_i3c_hci_dat_v1.set_dynamic_addr(hci, ret, dev->info.dyn_addr);
396 		dev_data->dat_idx = ret;
397 	}
398 	i3c_dev_set_master_data(dev, dev_data);
399 	return 0;
400 }
401 
402 static int i3c_hci_reattach_i3c_dev(struct i3c_dev_desc *dev, u8 old_dyn_addr)
403 {
404 	struct i3c_master_controller *m = i3c_dev_get_master(dev);
405 	struct i3c_hci *hci = to_i3c_hci(m);
406 	struct i3c_hci_dev_data *dev_data = i3c_dev_get_master_data(dev);
407 
408 	DBG("");
409 
410 	if (hci->cmd == &mipi_i3c_hci_cmd_v1)
411 		mipi_i3c_hci_dat_v1.set_dynamic_addr(hci, dev_data->dat_idx,
412 					     dev->info.dyn_addr);
413 	return 0;
414 }
415 
416 static void i3c_hci_detach_i3c_dev(struct i3c_dev_desc *dev)
417 {
418 	struct i3c_master_controller *m = i3c_dev_get_master(dev);
419 	struct i3c_hci *hci = to_i3c_hci(m);
420 	struct i3c_hci_dev_data *dev_data = i3c_dev_get_master_data(dev);
421 
422 	DBG("");
423 
424 	i3c_dev_set_master_data(dev, NULL);
425 	if (hci->cmd == &mipi_i3c_hci_cmd_v1)
426 		mipi_i3c_hci_dat_v1.free_entry(hci, dev_data->dat_idx);
427 	kfree(dev_data);
428 }
429 
430 static int i3c_hci_attach_i2c_dev(struct i2c_dev_desc *dev)
431 {
432 	struct i3c_master_controller *m = i2c_dev_get_master(dev);
433 	struct i3c_hci *hci = to_i3c_hci(m);
434 	struct i3c_hci_dev_data *dev_data;
435 	int ret;
436 
437 	DBG("");
438 
439 	if (hci->cmd != &mipi_i3c_hci_cmd_v1)
440 		return 0;
441 	dev_data = kzalloc(sizeof(*dev_data), GFP_KERNEL);
442 	if (!dev_data)
443 		return -ENOMEM;
444 	ret = mipi_i3c_hci_dat_v1.alloc_entry(hci);
445 	if (ret < 0) {
446 		kfree(dev_data);
447 		return ret;
448 	}
449 	mipi_i3c_hci_dat_v1.set_static_addr(hci, ret, dev->addr);
450 	mipi_i3c_hci_dat_v1.set_flags(hci, ret, DAT_0_I2C_DEVICE, 0);
451 	dev_data->dat_idx = ret;
452 	i2c_dev_set_master_data(dev, dev_data);
453 	return 0;
454 }
455 
456 static void i3c_hci_detach_i2c_dev(struct i2c_dev_desc *dev)
457 {
458 	struct i3c_master_controller *m = i2c_dev_get_master(dev);
459 	struct i3c_hci *hci = to_i3c_hci(m);
460 	struct i3c_hci_dev_data *dev_data = i2c_dev_get_master_data(dev);
461 
462 	DBG("");
463 
464 	if (dev_data) {
465 		i2c_dev_set_master_data(dev, NULL);
466 		if (hci->cmd == &mipi_i3c_hci_cmd_v1)
467 			mipi_i3c_hci_dat_v1.free_entry(hci, dev_data->dat_idx);
468 		kfree(dev_data);
469 	}
470 }
471 
472 static int i3c_hci_request_ibi(struct i3c_dev_desc *dev,
473 			       const struct i3c_ibi_setup *req)
474 {
475 	struct i3c_master_controller *m = i3c_dev_get_master(dev);
476 	struct i3c_hci *hci = to_i3c_hci(m);
477 	struct i3c_hci_dev_data *dev_data = i3c_dev_get_master_data(dev);
478 	unsigned int dat_idx = dev_data->dat_idx;
479 
480 	if (req->max_payload_len != 0)
481 		mipi_i3c_hci_dat_v1.set_flags(hci, dat_idx, DAT_0_IBI_PAYLOAD, 0);
482 	else
483 		mipi_i3c_hci_dat_v1.clear_flags(hci, dat_idx, DAT_0_IBI_PAYLOAD, 0);
484 	return hci->io->request_ibi(hci, dev, req);
485 }
486 
487 static void i3c_hci_free_ibi(struct i3c_dev_desc *dev)
488 {
489 	struct i3c_master_controller *m = i3c_dev_get_master(dev);
490 	struct i3c_hci *hci = to_i3c_hci(m);
491 
492 	hci->io->free_ibi(hci, dev);
493 }
494 
495 static int i3c_hci_enable_ibi(struct i3c_dev_desc *dev)
496 {
497 	struct i3c_master_controller *m = i3c_dev_get_master(dev);
498 	struct i3c_hci *hci = to_i3c_hci(m);
499 	struct i3c_hci_dev_data *dev_data = i3c_dev_get_master_data(dev);
500 
501 	mipi_i3c_hci_dat_v1.clear_flags(hci, dev_data->dat_idx, DAT_0_SIR_REJECT, 0);
502 	return i3c_master_enec_locked(m, dev->info.dyn_addr, I3C_CCC_EVENT_SIR);
503 }
504 
505 static int i3c_hci_disable_ibi(struct i3c_dev_desc *dev)
506 {
507 	struct i3c_master_controller *m = i3c_dev_get_master(dev);
508 	struct i3c_hci *hci = to_i3c_hci(m);
509 	struct i3c_hci_dev_data *dev_data = i3c_dev_get_master_data(dev);
510 
511 	mipi_i3c_hci_dat_v1.set_flags(hci, dev_data->dat_idx, DAT_0_SIR_REJECT, 0);
512 	return i3c_master_disec_locked(m, dev->info.dyn_addr, I3C_CCC_EVENT_SIR);
513 }
514 
515 static void i3c_hci_recycle_ibi_slot(struct i3c_dev_desc *dev,
516 				     struct i3c_ibi_slot *slot)
517 {
518 	struct i3c_master_controller *m = i3c_dev_get_master(dev);
519 	struct i3c_hci *hci = to_i3c_hci(m);
520 
521 	hci->io->recycle_ibi_slot(hci, dev, slot);
522 }
523 
524 static const struct i3c_master_controller_ops i3c_hci_ops = {
525 	.bus_init		= i3c_hci_bus_init,
526 	.bus_cleanup		= i3c_hci_bus_cleanup,
527 	.do_daa			= i3c_hci_daa,
528 	.send_ccc_cmd		= i3c_hci_send_ccc_cmd,
529 	.priv_xfers		= i3c_hci_priv_xfers,
530 	.i2c_xfers		= i3c_hci_i2c_xfers,
531 	.attach_i3c_dev		= i3c_hci_attach_i3c_dev,
532 	.reattach_i3c_dev	= i3c_hci_reattach_i3c_dev,
533 	.detach_i3c_dev		= i3c_hci_detach_i3c_dev,
534 	.attach_i2c_dev		= i3c_hci_attach_i2c_dev,
535 	.detach_i2c_dev		= i3c_hci_detach_i2c_dev,
536 	.request_ibi		= i3c_hci_request_ibi,
537 	.free_ibi		= i3c_hci_free_ibi,
538 	.enable_ibi		= i3c_hci_enable_ibi,
539 	.disable_ibi		= i3c_hci_disable_ibi,
540 	.recycle_ibi_slot	= i3c_hci_recycle_ibi_slot,
541 };
542 
543 static irqreturn_t i3c_hci_irq_handler(int irq, void *dev_id)
544 {
545 	struct i3c_hci *hci = dev_id;
546 	irqreturn_t result = IRQ_NONE;
547 	u32 val;
548 
549 	val = reg_read(INTR_STATUS);
550 	DBG("INTR_STATUS = %#x", val);
551 
552 	if (val) {
553 		reg_write(INTR_STATUS, val);
554 	} else {
555 		/* v1.0 does not have PIO cascaded notification bits */
556 		val |= INTR_HC_PIO;
557 	}
558 
559 	if (val & INTR_HC_RESET_CANCEL) {
560 		DBG("cancelled reset");
561 		val &= ~INTR_HC_RESET_CANCEL;
562 	}
563 	if (val & INTR_HC_INTERNAL_ERR) {
564 		dev_err(&hci->master.dev, "Host Controller Internal Error\n");
565 		val &= ~INTR_HC_INTERNAL_ERR;
566 	}
567 	if (val & INTR_HC_PIO) {
568 		hci->io->irq_handler(hci, 0);
569 		val &= ~INTR_HC_PIO;
570 	}
571 	if (val & INTR_HC_RINGS) {
572 		hci->io->irq_handler(hci, val & INTR_HC_RINGS);
573 		val &= ~INTR_HC_RINGS;
574 	}
575 	if (val)
576 		dev_err(&hci->master.dev, "unexpected INTR_STATUS %#x\n", val);
577 	else
578 		result = IRQ_HANDLED;
579 
580 	return result;
581 }
582 
583 static int i3c_hci_init(struct i3c_hci *hci)
584 {
585 	u32 regval, offset;
586 	int ret;
587 
588 	/* Validate HCI hardware version */
589 	regval = reg_read(HCI_VERSION);
590 	hci->version_major = (regval >> 8) & 0xf;
591 	hci->version_minor = (regval >> 4) & 0xf;
592 	hci->revision = regval & 0xf;
593 	dev_notice(&hci->master.dev, "MIPI I3C HCI v%u.%u r%02u\n",
594 		   hci->version_major, hci->version_minor, hci->revision);
595 	/* known versions */
596 	switch (regval & ~0xf) {
597 	case 0x100:	/* version 1.0 */
598 	case 0x110:	/* version 1.1 */
599 	case 0x200:	/* version 2.0 */
600 		break;
601 	default:
602 		dev_err(&hci->master.dev, "unsupported HCI version\n");
603 		return -EPROTONOSUPPORT;
604 	}
605 
606 	hci->caps = reg_read(HC_CAPABILITIES);
607 	DBG("caps = %#x", hci->caps);
608 
609 	regval = reg_read(DAT_SECTION);
610 	offset = FIELD_GET(DAT_TABLE_OFFSET, regval);
611 	hci->DAT_regs = offset ? hci->base_regs + offset : NULL;
612 	hci->DAT_entries = FIELD_GET(DAT_TABLE_SIZE, regval);
613 	hci->DAT_entry_size = FIELD_GET(DAT_ENTRY_SIZE, regval);
614 	dev_info(&hci->master.dev, "DAT: %u %u-bytes entries at offset %#x\n",
615 		 hci->DAT_entries, hci->DAT_entry_size * 4, offset);
616 
617 	regval = reg_read(DCT_SECTION);
618 	offset = FIELD_GET(DCT_TABLE_OFFSET, regval);
619 	hci->DCT_regs = offset ? hci->base_regs + offset : NULL;
620 	hci->DCT_entries = FIELD_GET(DCT_TABLE_SIZE, regval);
621 	hci->DCT_entry_size = FIELD_GET(DCT_ENTRY_SIZE, regval);
622 	dev_info(&hci->master.dev, "DCT: %u %u-bytes entries at offset %#x\n",
623 		 hci->DCT_entries, hci->DCT_entry_size * 4, offset);
624 
625 	regval = reg_read(RING_HEADERS_SECTION);
626 	offset = FIELD_GET(RING_HEADERS_OFFSET, regval);
627 	hci->RHS_regs = offset ? hci->base_regs + offset : NULL;
628 	dev_info(&hci->master.dev, "Ring Headers at offset %#x\n", offset);
629 
630 	regval = reg_read(PIO_SECTION);
631 	offset = FIELD_GET(PIO_REGS_OFFSET, regval);
632 	hci->PIO_regs = offset ? hci->base_regs + offset : NULL;
633 	dev_info(&hci->master.dev, "PIO section at offset %#x\n", offset);
634 
635 	regval = reg_read(EXT_CAPS_SECTION);
636 	offset = FIELD_GET(EXT_CAPS_OFFSET, regval);
637 	hci->EXTCAPS_regs = offset ? hci->base_regs + offset : NULL;
638 	dev_info(&hci->master.dev, "Extended Caps at offset %#x\n", offset);
639 
640 	ret = i3c_hci_parse_ext_caps(hci);
641 	if (ret)
642 		return ret;
643 
644 	/*
645 	 * Now let's reset the hardware.
646 	 * SOFT_RST must be clear before we write to it.
647 	 * Then we must wait until it clears again.
648 	 */
649 	ret = readx_poll_timeout(reg_read, RESET_CONTROL, regval,
650 				 !(regval & SOFT_RST), 1, 10000);
651 	if (ret)
652 		return -ENXIO;
653 	reg_write(RESET_CONTROL, SOFT_RST);
654 	ret = readx_poll_timeout(reg_read, RESET_CONTROL, regval,
655 				 !(regval & SOFT_RST), 1, 10000);
656 	if (ret)
657 		return -ENXIO;
658 
659 	/* Disable all interrupts and allow all signal updates */
660 	reg_write(INTR_SIGNAL_ENABLE, 0x0);
661 	reg_write(INTR_STATUS_ENABLE, 0xffffffff);
662 
663 	/* Make sure our data ordering fits the host's */
664 	regval = reg_read(HC_CONTROL);
665 	if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN)) {
666 		if (!(regval & HC_CONTROL_DATA_BIG_ENDIAN)) {
667 			regval |= HC_CONTROL_DATA_BIG_ENDIAN;
668 			reg_write(HC_CONTROL, regval);
669 			regval = reg_read(HC_CONTROL);
670 			if (!(regval & HC_CONTROL_DATA_BIG_ENDIAN)) {
671 				dev_err(&hci->master.dev, "cannot set BE mode\n");
672 				return -EOPNOTSUPP;
673 			}
674 		}
675 	} else {
676 		if (regval & HC_CONTROL_DATA_BIG_ENDIAN) {
677 			regval &= ~HC_CONTROL_DATA_BIG_ENDIAN;
678 			reg_write(HC_CONTROL, regval);
679 			regval = reg_read(HC_CONTROL);
680 			if (regval & HC_CONTROL_DATA_BIG_ENDIAN) {
681 				dev_err(&hci->master.dev, "cannot clear BE mode\n");
682 				return -EOPNOTSUPP;
683 			}
684 		}
685 	}
686 
687 	/* Select our command descriptor model */
688 	switch (FIELD_GET(HC_CAP_CMD_SIZE, hci->caps)) {
689 	case 0:
690 		hci->cmd = &mipi_i3c_hci_cmd_v1;
691 		break;
692 	case 1:
693 		hci->cmd = &mipi_i3c_hci_cmd_v2;
694 		break;
695 	default:
696 		dev_err(&hci->master.dev, "wrong CMD_SIZE capability value\n");
697 		return -EINVAL;
698 	}
699 
700 	/* Try activating DMA operations first */
701 	if (hci->RHS_regs) {
702 		reg_clear(HC_CONTROL, HC_CONTROL_PIO_MODE);
703 		if (reg_read(HC_CONTROL) & HC_CONTROL_PIO_MODE) {
704 			dev_err(&hci->master.dev, "PIO mode is stuck\n");
705 			ret = -EIO;
706 		} else {
707 			hci->io = &mipi_i3c_hci_dma;
708 			dev_info(&hci->master.dev, "Using DMA\n");
709 		}
710 	}
711 
712 	/* If no DMA, try PIO */
713 	if (!hci->io && hci->PIO_regs) {
714 		reg_set(HC_CONTROL, HC_CONTROL_PIO_MODE);
715 		if (!(reg_read(HC_CONTROL) & HC_CONTROL_PIO_MODE)) {
716 			dev_err(&hci->master.dev, "DMA mode is stuck\n");
717 			ret = -EIO;
718 		} else {
719 			hci->io = &mipi_i3c_hci_pio;
720 			dev_info(&hci->master.dev, "Using PIO\n");
721 		}
722 	}
723 
724 	if (!hci->io) {
725 		dev_err(&hci->master.dev, "neither DMA nor PIO can be used\n");
726 		if (!ret)
727 			ret = -EINVAL;
728 		return ret;
729 	}
730 
731 	return 0;
732 }
733 
734 static int i3c_hci_probe(struct platform_device *pdev)
735 {
736 	struct i3c_hci *hci;
737 	int irq, ret;
738 
739 	hci = devm_kzalloc(&pdev->dev, sizeof(*hci), GFP_KERNEL);
740 	if (!hci)
741 		return -ENOMEM;
742 	hci->base_regs = devm_platform_ioremap_resource(pdev, 0);
743 	if (IS_ERR(hci->base_regs))
744 		return PTR_ERR(hci->base_regs);
745 
746 	platform_set_drvdata(pdev, hci);
747 	/* temporary for dev_printk's, to be replaced in i3c_master_register */
748 	hci->master.dev.init_name = dev_name(&pdev->dev);
749 
750 	ret = i3c_hci_init(hci);
751 	if (ret)
752 		return ret;
753 
754 	irq = platform_get_irq(pdev, 0);
755 	ret = devm_request_irq(&pdev->dev, irq, i3c_hci_irq_handler,
756 			       0, NULL, hci);
757 	if (ret)
758 		return ret;
759 
760 	ret = i3c_master_register(&hci->master, &pdev->dev,
761 				  &i3c_hci_ops, false);
762 	if (ret)
763 		return ret;
764 
765 	return 0;
766 }
767 
768 static int i3c_hci_remove(struct platform_device *pdev)
769 {
770 	struct i3c_hci *hci = platform_get_drvdata(pdev);
771 
772 	return i3c_master_unregister(&hci->master);
773 }
774 
775 static const __maybe_unused struct of_device_id i3c_hci_of_match[] = {
776 	{ .compatible = "mipi-i3c-hci", },
777 	{},
778 };
779 MODULE_DEVICE_TABLE(of, i3c_hci_of_match);
780 
781 static struct platform_driver i3c_hci_driver = {
782 	.probe = i3c_hci_probe,
783 	.remove = i3c_hci_remove,
784 	.driver = {
785 		.name = "mipi-i3c-hci",
786 		.of_match_table = of_match_ptr(i3c_hci_of_match),
787 	},
788 };
789 module_platform_driver(i3c_hci_driver);
790 
791 MODULE_AUTHOR("Nicolas Pitre <npitre@baylibre.com>");
792 MODULE_DESCRIPTION("MIPI I3C HCI driver");
793 MODULE_LICENSE("Dual BSD/GPL");
794