xref: /linux/drivers/i3c/master/mipi-i3c-hci/core.c (revision 3d0fe49454652117522f60bfbefb978ba0e5300b)
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 	struct platform_device *pdev = to_platform_device(m->dev.parent);
165 
166 	DBG("");
167 
168 	reg_clear(HC_CONTROL, HC_CONTROL_BUS_ENABLE);
169 	synchronize_irq(platform_get_irq(pdev, 0));
170 	hci->io->cleanup(hci);
171 	if (hci->cmd == &mipi_i3c_hci_cmd_v1)
172 		mipi_i3c_hci_dat_v1.cleanup(hci);
173 }
174 
175 void mipi_i3c_hci_resume(struct i3c_hci *hci)
176 {
177 	reg_set(HC_CONTROL, HC_CONTROL_RESUME);
178 }
179 
180 /* located here rather than pio.c because needed bits are in core reg space */
181 void mipi_i3c_hci_pio_reset(struct i3c_hci *hci)
182 {
183 	reg_write(RESET_CONTROL, RX_FIFO_RST | TX_FIFO_RST | RESP_QUEUE_RST);
184 }
185 
186 /* located here rather than dct.c because needed bits are in core reg space */
187 void mipi_i3c_hci_dct_index_reset(struct i3c_hci *hci)
188 {
189 	reg_write(DCT_SECTION, FIELD_PREP(DCT_TABLE_INDEX, 0));
190 }
191 
192 static int i3c_hci_send_ccc_cmd(struct i3c_master_controller *m,
193 				struct i3c_ccc_cmd *ccc)
194 {
195 	struct i3c_hci *hci = to_i3c_hci(m);
196 	struct hci_xfer *xfer;
197 	bool raw = !!(hci->quirks & HCI_QUIRK_RAW_CCC);
198 	bool prefixed = raw && !!(ccc->id & I3C_CCC_DIRECT);
199 	unsigned int nxfers = ccc->ndests + prefixed;
200 	DECLARE_COMPLETION_ONSTACK(done);
201 	int i, last, ret = 0;
202 
203 	DBG("cmd=%#x rnw=%d ndests=%d data[0].len=%d",
204 	    ccc->id, ccc->rnw, ccc->ndests, ccc->dests[0].payload.len);
205 
206 	xfer = hci_alloc_xfer(nxfers);
207 	if (!xfer)
208 		return -ENOMEM;
209 
210 	if (prefixed) {
211 		xfer->data = NULL;
212 		xfer->data_len = 0;
213 		xfer->rnw = false;
214 		hci->cmd->prep_ccc(hci, xfer, I3C_BROADCAST_ADDR,
215 				   ccc->id, true);
216 		xfer++;
217 	}
218 
219 	for (i = 0; i < nxfers - prefixed; i++) {
220 		xfer[i].data = ccc->dests[i].payload.data;
221 		xfer[i].data_len = ccc->dests[i].payload.len;
222 		xfer[i].rnw = ccc->rnw;
223 		ret = hci->cmd->prep_ccc(hci, &xfer[i], ccc->dests[i].addr,
224 					 ccc->id, raw);
225 		if (ret)
226 			goto out;
227 		xfer[i].cmd_desc[0] |= CMD_0_ROC;
228 	}
229 	last = i - 1;
230 	xfer[last].cmd_desc[0] |= CMD_0_TOC;
231 	xfer[last].completion = &done;
232 
233 	if (prefixed)
234 		xfer--;
235 
236 	ret = hci->io->queue_xfer(hci, xfer, nxfers);
237 	if (ret)
238 		goto out;
239 	if (!wait_for_completion_timeout(&done, HZ) &&
240 	    hci->io->dequeue_xfer(hci, xfer, nxfers)) {
241 		ret = -ETIME;
242 		goto out;
243 	}
244 	for (i = prefixed; i < nxfers; i++) {
245 		if (ccc->rnw)
246 			ccc->dests[i - prefixed].payload.len =
247 				RESP_DATA_LENGTH(xfer[i].response);
248 		if (RESP_STATUS(xfer[i].response) != RESP_SUCCESS) {
249 			ret = -EIO;
250 			goto out;
251 		}
252 	}
253 
254 	if (ccc->rnw)
255 		DBG("got: %*ph",
256 		    ccc->dests[0].payload.len, ccc->dests[0].payload.data);
257 
258 out:
259 	hci_free_xfer(xfer, nxfers);
260 	return ret;
261 }
262 
263 static int i3c_hci_daa(struct i3c_master_controller *m)
264 {
265 	struct i3c_hci *hci = to_i3c_hci(m);
266 
267 	DBG("");
268 
269 	return hci->cmd->perform_daa(hci);
270 }
271 
272 static int i3c_hci_priv_xfers(struct i3c_dev_desc *dev,
273 			      struct i3c_priv_xfer *i3c_xfers,
274 			      int nxfers)
275 {
276 	struct i3c_master_controller *m = i3c_dev_get_master(dev);
277 	struct i3c_hci *hci = to_i3c_hci(m);
278 	struct hci_xfer *xfer;
279 	DECLARE_COMPLETION_ONSTACK(done);
280 	unsigned int size_limit;
281 	int i, last, ret = 0;
282 
283 	DBG("nxfers = %d", nxfers);
284 
285 	xfer = hci_alloc_xfer(nxfers);
286 	if (!xfer)
287 		return -ENOMEM;
288 
289 	size_limit = 1U << (16 + FIELD_GET(HC_CAP_MAX_DATA_LENGTH, hci->caps));
290 
291 	for (i = 0; i < nxfers; i++) {
292 		xfer[i].data_len = i3c_xfers[i].len;
293 		ret = -EFBIG;
294 		if (xfer[i].data_len >= size_limit)
295 			goto out;
296 		xfer[i].rnw = i3c_xfers[i].rnw;
297 		if (i3c_xfers[i].rnw) {
298 			xfer[i].data = i3c_xfers[i].data.in;
299 		} else {
300 			/* silence the const qualifier warning with a cast */
301 			xfer[i].data = (void *) i3c_xfers[i].data.out;
302 		}
303 		hci->cmd->prep_i3c_xfer(hci, dev, &xfer[i]);
304 		xfer[i].cmd_desc[0] |= CMD_0_ROC;
305 	}
306 	last = i - 1;
307 	xfer[last].cmd_desc[0] |= CMD_0_TOC;
308 	xfer[last].completion = &done;
309 
310 	ret = hci->io->queue_xfer(hci, xfer, nxfers);
311 	if (ret)
312 		goto out;
313 	if (!wait_for_completion_timeout(&done, HZ) &&
314 	    hci->io->dequeue_xfer(hci, xfer, nxfers)) {
315 		ret = -ETIME;
316 		goto out;
317 	}
318 	for (i = 0; i < nxfers; i++) {
319 		if (i3c_xfers[i].rnw)
320 			i3c_xfers[i].len = RESP_DATA_LENGTH(xfer[i].response);
321 		if (RESP_STATUS(xfer[i].response) != RESP_SUCCESS) {
322 			ret = -EIO;
323 			goto out;
324 		}
325 	}
326 
327 out:
328 	hci_free_xfer(xfer, nxfers);
329 	return ret;
330 }
331 
332 static int i3c_hci_i2c_xfers(struct i2c_dev_desc *dev,
333 			     const struct i2c_msg *i2c_xfers, int nxfers)
334 {
335 	struct i3c_master_controller *m = i2c_dev_get_master(dev);
336 	struct i3c_hci *hci = to_i3c_hci(m);
337 	struct hci_xfer *xfer;
338 	DECLARE_COMPLETION_ONSTACK(done);
339 	int i, last, ret = 0;
340 
341 	DBG("nxfers = %d", nxfers);
342 
343 	xfer = hci_alloc_xfer(nxfers);
344 	if (!xfer)
345 		return -ENOMEM;
346 
347 	for (i = 0; i < nxfers; i++) {
348 		xfer[i].data = i2c_xfers[i].buf;
349 		xfer[i].data_len = i2c_xfers[i].len;
350 		xfer[i].rnw = i2c_xfers[i].flags & I2C_M_RD;
351 		hci->cmd->prep_i2c_xfer(hci, dev, &xfer[i]);
352 		xfer[i].cmd_desc[0] |= CMD_0_ROC;
353 	}
354 	last = i - 1;
355 	xfer[last].cmd_desc[0] |= CMD_0_TOC;
356 	xfer[last].completion = &done;
357 
358 	ret = hci->io->queue_xfer(hci, xfer, nxfers);
359 	if (ret)
360 		goto out;
361 	if (!wait_for_completion_timeout(&done, HZ) &&
362 	    hci->io->dequeue_xfer(hci, xfer, nxfers)) {
363 		ret = -ETIME;
364 		goto out;
365 	}
366 	for (i = 0; i < nxfers; i++) {
367 		if (RESP_STATUS(xfer[i].response) != RESP_SUCCESS) {
368 			ret = -EIO;
369 			goto out;
370 		}
371 	}
372 
373 out:
374 	hci_free_xfer(xfer, nxfers);
375 	return ret;
376 }
377 
378 static int i3c_hci_attach_i3c_dev(struct i3c_dev_desc *dev)
379 {
380 	struct i3c_master_controller *m = i3c_dev_get_master(dev);
381 	struct i3c_hci *hci = to_i3c_hci(m);
382 	struct i3c_hci_dev_data *dev_data;
383 	int ret;
384 
385 	DBG("");
386 
387 	dev_data = kzalloc(sizeof(*dev_data), GFP_KERNEL);
388 	if (!dev_data)
389 		return -ENOMEM;
390 	if (hci->cmd == &mipi_i3c_hci_cmd_v1) {
391 		ret = mipi_i3c_hci_dat_v1.alloc_entry(hci);
392 		if (ret < 0) {
393 			kfree(dev_data);
394 			return ret;
395 		}
396 		mipi_i3c_hci_dat_v1.set_dynamic_addr(hci, ret, dev->info.dyn_addr);
397 		dev_data->dat_idx = ret;
398 	}
399 	i3c_dev_set_master_data(dev, dev_data);
400 	return 0;
401 }
402 
403 static int i3c_hci_reattach_i3c_dev(struct i3c_dev_desc *dev, u8 old_dyn_addr)
404 {
405 	struct i3c_master_controller *m = i3c_dev_get_master(dev);
406 	struct i3c_hci *hci = to_i3c_hci(m);
407 	struct i3c_hci_dev_data *dev_data = i3c_dev_get_master_data(dev);
408 
409 	DBG("");
410 
411 	if (hci->cmd == &mipi_i3c_hci_cmd_v1)
412 		mipi_i3c_hci_dat_v1.set_dynamic_addr(hci, dev_data->dat_idx,
413 					     dev->info.dyn_addr);
414 	return 0;
415 }
416 
417 static void i3c_hci_detach_i3c_dev(struct i3c_dev_desc *dev)
418 {
419 	struct i3c_master_controller *m = i3c_dev_get_master(dev);
420 	struct i3c_hci *hci = to_i3c_hci(m);
421 	struct i3c_hci_dev_data *dev_data = i3c_dev_get_master_data(dev);
422 
423 	DBG("");
424 
425 	i3c_dev_set_master_data(dev, NULL);
426 	if (hci->cmd == &mipi_i3c_hci_cmd_v1)
427 		mipi_i3c_hci_dat_v1.free_entry(hci, dev_data->dat_idx);
428 	kfree(dev_data);
429 }
430 
431 static int i3c_hci_attach_i2c_dev(struct i2c_dev_desc *dev)
432 {
433 	struct i3c_master_controller *m = i2c_dev_get_master(dev);
434 	struct i3c_hci *hci = to_i3c_hci(m);
435 	struct i3c_hci_dev_data *dev_data;
436 	int ret;
437 
438 	DBG("");
439 
440 	if (hci->cmd != &mipi_i3c_hci_cmd_v1)
441 		return 0;
442 	dev_data = kzalloc(sizeof(*dev_data), GFP_KERNEL);
443 	if (!dev_data)
444 		return -ENOMEM;
445 	ret = mipi_i3c_hci_dat_v1.alloc_entry(hci);
446 	if (ret < 0) {
447 		kfree(dev_data);
448 		return ret;
449 	}
450 	mipi_i3c_hci_dat_v1.set_static_addr(hci, ret, dev->addr);
451 	mipi_i3c_hci_dat_v1.set_flags(hci, ret, DAT_0_I2C_DEVICE, 0);
452 	dev_data->dat_idx = ret;
453 	i2c_dev_set_master_data(dev, dev_data);
454 	return 0;
455 }
456 
457 static void i3c_hci_detach_i2c_dev(struct i2c_dev_desc *dev)
458 {
459 	struct i3c_master_controller *m = i2c_dev_get_master(dev);
460 	struct i3c_hci *hci = to_i3c_hci(m);
461 	struct i3c_hci_dev_data *dev_data = i2c_dev_get_master_data(dev);
462 
463 	DBG("");
464 
465 	if (dev_data) {
466 		i2c_dev_set_master_data(dev, NULL);
467 		if (hci->cmd == &mipi_i3c_hci_cmd_v1)
468 			mipi_i3c_hci_dat_v1.free_entry(hci, dev_data->dat_idx);
469 		kfree(dev_data);
470 	}
471 }
472 
473 static int i3c_hci_request_ibi(struct i3c_dev_desc *dev,
474 			       const struct i3c_ibi_setup *req)
475 {
476 	struct i3c_master_controller *m = i3c_dev_get_master(dev);
477 	struct i3c_hci *hci = to_i3c_hci(m);
478 	struct i3c_hci_dev_data *dev_data = i3c_dev_get_master_data(dev);
479 	unsigned int dat_idx = dev_data->dat_idx;
480 
481 	if (req->max_payload_len != 0)
482 		mipi_i3c_hci_dat_v1.set_flags(hci, dat_idx, DAT_0_IBI_PAYLOAD, 0);
483 	else
484 		mipi_i3c_hci_dat_v1.clear_flags(hci, dat_idx, DAT_0_IBI_PAYLOAD, 0);
485 	return hci->io->request_ibi(hci, dev, req);
486 }
487 
488 static void i3c_hci_free_ibi(struct i3c_dev_desc *dev)
489 {
490 	struct i3c_master_controller *m = i3c_dev_get_master(dev);
491 	struct i3c_hci *hci = to_i3c_hci(m);
492 
493 	hci->io->free_ibi(hci, dev);
494 }
495 
496 static int i3c_hci_enable_ibi(struct i3c_dev_desc *dev)
497 {
498 	struct i3c_master_controller *m = i3c_dev_get_master(dev);
499 	struct i3c_hci *hci = to_i3c_hci(m);
500 	struct i3c_hci_dev_data *dev_data = i3c_dev_get_master_data(dev);
501 
502 	mipi_i3c_hci_dat_v1.clear_flags(hci, dev_data->dat_idx, DAT_0_SIR_REJECT, 0);
503 	return i3c_master_enec_locked(m, dev->info.dyn_addr, I3C_CCC_EVENT_SIR);
504 }
505 
506 static int i3c_hci_disable_ibi(struct i3c_dev_desc *dev)
507 {
508 	struct i3c_master_controller *m = i3c_dev_get_master(dev);
509 	struct i3c_hci *hci = to_i3c_hci(m);
510 	struct i3c_hci_dev_data *dev_data = i3c_dev_get_master_data(dev);
511 
512 	mipi_i3c_hci_dat_v1.set_flags(hci, dev_data->dat_idx, DAT_0_SIR_REJECT, 0);
513 	return i3c_master_disec_locked(m, dev->info.dyn_addr, I3C_CCC_EVENT_SIR);
514 }
515 
516 static void i3c_hci_recycle_ibi_slot(struct i3c_dev_desc *dev,
517 				     struct i3c_ibi_slot *slot)
518 {
519 	struct i3c_master_controller *m = i3c_dev_get_master(dev);
520 	struct i3c_hci *hci = to_i3c_hci(m);
521 
522 	hci->io->recycle_ibi_slot(hci, dev, slot);
523 }
524 
525 static const struct i3c_master_controller_ops i3c_hci_ops = {
526 	.bus_init		= i3c_hci_bus_init,
527 	.bus_cleanup		= i3c_hci_bus_cleanup,
528 	.do_daa			= i3c_hci_daa,
529 	.send_ccc_cmd		= i3c_hci_send_ccc_cmd,
530 	.priv_xfers		= i3c_hci_priv_xfers,
531 	.i2c_xfers		= i3c_hci_i2c_xfers,
532 	.attach_i3c_dev		= i3c_hci_attach_i3c_dev,
533 	.reattach_i3c_dev	= i3c_hci_reattach_i3c_dev,
534 	.detach_i3c_dev		= i3c_hci_detach_i3c_dev,
535 	.attach_i2c_dev		= i3c_hci_attach_i2c_dev,
536 	.detach_i2c_dev		= i3c_hci_detach_i2c_dev,
537 	.request_ibi		= i3c_hci_request_ibi,
538 	.free_ibi		= i3c_hci_free_ibi,
539 	.enable_ibi		= i3c_hci_enable_ibi,
540 	.disable_ibi		= i3c_hci_disable_ibi,
541 	.recycle_ibi_slot	= i3c_hci_recycle_ibi_slot,
542 };
543 
544 static irqreturn_t i3c_hci_irq_handler(int irq, void *dev_id)
545 {
546 	struct i3c_hci *hci = dev_id;
547 	irqreturn_t result = IRQ_NONE;
548 	u32 val;
549 
550 	val = reg_read(INTR_STATUS);
551 	DBG("INTR_STATUS = %#x", val);
552 
553 	if (val) {
554 		reg_write(INTR_STATUS, val);
555 	} else {
556 		/* v1.0 does not have PIO cascaded notification bits */
557 		val |= INTR_HC_PIO;
558 	}
559 
560 	if (val & INTR_HC_RESET_CANCEL) {
561 		DBG("cancelled reset");
562 		val &= ~INTR_HC_RESET_CANCEL;
563 	}
564 	if (val & INTR_HC_INTERNAL_ERR) {
565 		dev_err(&hci->master.dev, "Host Controller Internal Error\n");
566 		val &= ~INTR_HC_INTERNAL_ERR;
567 	}
568 	if (val & INTR_HC_PIO) {
569 		hci->io->irq_handler(hci, 0);
570 		val &= ~INTR_HC_PIO;
571 	}
572 	if (val & INTR_HC_RINGS) {
573 		hci->io->irq_handler(hci, val & INTR_HC_RINGS);
574 		val &= ~INTR_HC_RINGS;
575 	}
576 	if (val)
577 		dev_err(&hci->master.dev, "unexpected INTR_STATUS %#x\n", val);
578 	else
579 		result = IRQ_HANDLED;
580 
581 	return result;
582 }
583 
584 static int i3c_hci_init(struct i3c_hci *hci)
585 {
586 	u32 regval, offset;
587 	int ret;
588 
589 	/* Validate HCI hardware version */
590 	regval = reg_read(HCI_VERSION);
591 	hci->version_major = (regval >> 8) & 0xf;
592 	hci->version_minor = (regval >> 4) & 0xf;
593 	hci->revision = regval & 0xf;
594 	dev_notice(&hci->master.dev, "MIPI I3C HCI v%u.%u r%02u\n",
595 		   hci->version_major, hci->version_minor, hci->revision);
596 	/* known versions */
597 	switch (regval & ~0xf) {
598 	case 0x100:	/* version 1.0 */
599 	case 0x110:	/* version 1.1 */
600 	case 0x200:	/* version 2.0 */
601 		break;
602 	default:
603 		dev_err(&hci->master.dev, "unsupported HCI version\n");
604 		return -EPROTONOSUPPORT;
605 	}
606 
607 	hci->caps = reg_read(HC_CAPABILITIES);
608 	DBG("caps = %#x", hci->caps);
609 
610 	regval = reg_read(DAT_SECTION);
611 	offset = FIELD_GET(DAT_TABLE_OFFSET, regval);
612 	hci->DAT_regs = offset ? hci->base_regs + offset : NULL;
613 	hci->DAT_entries = FIELD_GET(DAT_TABLE_SIZE, regval);
614 	hci->DAT_entry_size = FIELD_GET(DAT_ENTRY_SIZE, regval) ? 0 : 8;
615 	dev_info(&hci->master.dev, "DAT: %u %u-bytes entries at offset %#x\n",
616 		 hci->DAT_entries, hci->DAT_entry_size, offset);
617 
618 	regval = reg_read(DCT_SECTION);
619 	offset = FIELD_GET(DCT_TABLE_OFFSET, regval);
620 	hci->DCT_regs = offset ? hci->base_regs + offset : NULL;
621 	hci->DCT_entries = FIELD_GET(DCT_TABLE_SIZE, regval);
622 	hci->DCT_entry_size = FIELD_GET(DCT_ENTRY_SIZE, regval) ? 0 : 16;
623 	dev_info(&hci->master.dev, "DCT: %u %u-bytes entries at offset %#x\n",
624 		 hci->DCT_entries, hci->DCT_entry_size, offset);
625 
626 	regval = reg_read(RING_HEADERS_SECTION);
627 	offset = FIELD_GET(RING_HEADERS_OFFSET, regval);
628 	hci->RHS_regs = offset ? hci->base_regs + offset : NULL;
629 	dev_info(&hci->master.dev, "Ring Headers at offset %#x\n", offset);
630 
631 	regval = reg_read(PIO_SECTION);
632 	offset = FIELD_GET(PIO_REGS_OFFSET, regval);
633 	hci->PIO_regs = offset ? hci->base_regs + offset : NULL;
634 	dev_info(&hci->master.dev, "PIO section at offset %#x\n", offset);
635 
636 	regval = reg_read(EXT_CAPS_SECTION);
637 	offset = FIELD_GET(EXT_CAPS_OFFSET, regval);
638 	hci->EXTCAPS_regs = offset ? hci->base_regs + offset : NULL;
639 	dev_info(&hci->master.dev, "Extended Caps at offset %#x\n", offset);
640 
641 	ret = i3c_hci_parse_ext_caps(hci);
642 	if (ret)
643 		return ret;
644 
645 	/*
646 	 * Now let's reset the hardware.
647 	 * SOFT_RST must be clear before we write to it.
648 	 * Then we must wait until it clears again.
649 	 */
650 	ret = readx_poll_timeout(reg_read, RESET_CONTROL, regval,
651 				 !(regval & SOFT_RST), 1, 10000);
652 	if (ret)
653 		return -ENXIO;
654 	reg_write(RESET_CONTROL, SOFT_RST);
655 	ret = readx_poll_timeout(reg_read, RESET_CONTROL, regval,
656 				 !(regval & SOFT_RST), 1, 10000);
657 	if (ret)
658 		return -ENXIO;
659 
660 	/* Disable all interrupts and allow all signal updates */
661 	reg_write(INTR_SIGNAL_ENABLE, 0x0);
662 	reg_write(INTR_STATUS_ENABLE, 0xffffffff);
663 
664 	/* Make sure our data ordering fits the host's */
665 	regval = reg_read(HC_CONTROL);
666 	if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN)) {
667 		if (!(regval & HC_CONTROL_DATA_BIG_ENDIAN)) {
668 			regval |= HC_CONTROL_DATA_BIG_ENDIAN;
669 			reg_write(HC_CONTROL, regval);
670 			regval = reg_read(HC_CONTROL);
671 			if (!(regval & HC_CONTROL_DATA_BIG_ENDIAN)) {
672 				dev_err(&hci->master.dev, "cannot set BE mode\n");
673 				return -EOPNOTSUPP;
674 			}
675 		}
676 	} else {
677 		if (regval & HC_CONTROL_DATA_BIG_ENDIAN) {
678 			regval &= ~HC_CONTROL_DATA_BIG_ENDIAN;
679 			reg_write(HC_CONTROL, regval);
680 			regval = reg_read(HC_CONTROL);
681 			if (regval & HC_CONTROL_DATA_BIG_ENDIAN) {
682 				dev_err(&hci->master.dev, "cannot clear BE mode\n");
683 				return -EOPNOTSUPP;
684 			}
685 		}
686 	}
687 
688 	/* Select our command descriptor model */
689 	switch (FIELD_GET(HC_CAP_CMD_SIZE, hci->caps)) {
690 	case 0:
691 		hci->cmd = &mipi_i3c_hci_cmd_v1;
692 		break;
693 	case 1:
694 		hci->cmd = &mipi_i3c_hci_cmd_v2;
695 		break;
696 	default:
697 		dev_err(&hci->master.dev, "wrong CMD_SIZE capability value\n");
698 		return -EINVAL;
699 	}
700 
701 	/* Try activating DMA operations first */
702 	if (hci->RHS_regs) {
703 		reg_clear(HC_CONTROL, HC_CONTROL_PIO_MODE);
704 		if (reg_read(HC_CONTROL) & HC_CONTROL_PIO_MODE) {
705 			dev_err(&hci->master.dev, "PIO mode is stuck\n");
706 			ret = -EIO;
707 		} else {
708 			hci->io = &mipi_i3c_hci_dma;
709 			dev_info(&hci->master.dev, "Using DMA\n");
710 		}
711 	}
712 
713 	/* If no DMA, try PIO */
714 	if (!hci->io && hci->PIO_regs) {
715 		reg_set(HC_CONTROL, HC_CONTROL_PIO_MODE);
716 		if (!(reg_read(HC_CONTROL) & HC_CONTROL_PIO_MODE)) {
717 			dev_err(&hci->master.dev, "DMA mode is stuck\n");
718 			ret = -EIO;
719 		} else {
720 			hci->io = &mipi_i3c_hci_pio;
721 			dev_info(&hci->master.dev, "Using PIO\n");
722 		}
723 	}
724 
725 	if (!hci->io) {
726 		dev_err(&hci->master.dev, "neither DMA nor PIO can be used\n");
727 		if (!ret)
728 			ret = -EINVAL;
729 		return ret;
730 	}
731 
732 	return 0;
733 }
734 
735 static int i3c_hci_probe(struct platform_device *pdev)
736 {
737 	struct i3c_hci *hci;
738 	int irq, ret;
739 
740 	hci = devm_kzalloc(&pdev->dev, sizeof(*hci), GFP_KERNEL);
741 	if (!hci)
742 		return -ENOMEM;
743 	hci->base_regs = devm_platform_ioremap_resource(pdev, 0);
744 	if (IS_ERR(hci->base_regs))
745 		return PTR_ERR(hci->base_regs);
746 
747 	platform_set_drvdata(pdev, hci);
748 	/* temporary for dev_printk's, to be replaced in i3c_master_register */
749 	hci->master.dev.init_name = dev_name(&pdev->dev);
750 
751 	ret = i3c_hci_init(hci);
752 	if (ret)
753 		return ret;
754 
755 	irq = platform_get_irq(pdev, 0);
756 	ret = devm_request_irq(&pdev->dev, irq, i3c_hci_irq_handler,
757 			       0, NULL, hci);
758 	if (ret)
759 		return ret;
760 
761 	ret = i3c_master_register(&hci->master, &pdev->dev,
762 				  &i3c_hci_ops, false);
763 	if (ret)
764 		return ret;
765 
766 	return 0;
767 }
768 
769 static void i3c_hci_remove(struct platform_device *pdev)
770 {
771 	struct i3c_hci *hci = platform_get_drvdata(pdev);
772 
773 	i3c_master_unregister(&hci->master);
774 }
775 
776 static const __maybe_unused struct of_device_id i3c_hci_of_match[] = {
777 	{ .compatible = "mipi-i3c-hci", },
778 	{},
779 };
780 MODULE_DEVICE_TABLE(of, i3c_hci_of_match);
781 
782 static struct platform_driver i3c_hci_driver = {
783 	.probe = i3c_hci_probe,
784 	.remove_new = i3c_hci_remove,
785 	.driver = {
786 		.name = "mipi-i3c-hci",
787 		.of_match_table = of_match_ptr(i3c_hci_of_match),
788 	},
789 };
790 module_platform_driver(i3c_hci_driver);
791 MODULE_ALIAS("platform:mipi-i3c-hci");
792 
793 MODULE_AUTHOR("Nicolas Pitre <npitre@baylibre.com>");
794 MODULE_DESCRIPTION("MIPI I3C HCI driver");
795 MODULE_LICENSE("Dual BSD/GPL");
796