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  * I3C HCI v1.0/v1.1 Command Descriptor Handling
8  */
9 
10 #include <linux/bitfield.h>
11 #include <linux/i3c/master.h>
12 
13 #include "hci.h"
14 #include "cmd.h"
15 #include "dat.h"
16 #include "dct.h"
17 
18 
19 /*
20  * Address Assignment Command
21  */
22 
23 #define CMD_0_ATTR_A			FIELD_PREP(CMD_0_ATTR, 0x2)
24 
25 #define CMD_A0_TOC				   W0_BIT_(31)
26 #define CMD_A0_ROC				   W0_BIT_(30)
27 #define CMD_A0_DEV_COUNT(v)		FIELD_PREP(W0_MASK(29, 26), v)
28 #define CMD_A0_DEV_INDEX(v)		FIELD_PREP(W0_MASK(20, 16), v)
29 #define CMD_A0_CMD(v)			FIELD_PREP(W0_MASK(14,  7), v)
30 #define CMD_A0_TID(v)			FIELD_PREP(W0_MASK( 6,  3), v)
31 
32 /*
33  * Immediate Data Transfer Command
34  */
35 
36 #define CMD_0_ATTR_I			FIELD_PREP(CMD_0_ATTR, 0x1)
37 
38 #define CMD_I1_DATA_BYTE_4(v)		FIELD_PREP(W1_MASK(63, 56), v)
39 #define CMD_I1_DATA_BYTE_3(v)		FIELD_PREP(W1_MASK(55, 48), v)
40 #define CMD_I1_DATA_BYTE_2(v)		FIELD_PREP(W1_MASK(47, 40), v)
41 #define CMD_I1_DATA_BYTE_1(v)		FIELD_PREP(W1_MASK(39, 32), v)
42 #define CMD_I1_DEF_BYTE(v)		FIELD_PREP(W1_MASK(39, 32), v)
43 #define CMD_I0_TOC				   W0_BIT_(31)
44 #define CMD_I0_ROC				   W0_BIT_(30)
45 #define CMD_I0_RNW				   W0_BIT_(29)
46 #define CMD_I0_MODE(v)			FIELD_PREP(W0_MASK(28, 26), v)
47 #define CMD_I0_DTT(v)			FIELD_PREP(W0_MASK(25, 23), v)
48 #define CMD_I0_DEV_INDEX(v)		FIELD_PREP(W0_MASK(20, 16), v)
49 #define CMD_I0_CP				   W0_BIT_(15)
50 #define CMD_I0_CMD(v)			FIELD_PREP(W0_MASK(14,  7), v)
51 #define CMD_I0_TID(v)			FIELD_PREP(W0_MASK( 6,  3), v)
52 
53 /*
54  * Regular Data Transfer Command
55  */
56 
57 #define CMD_0_ATTR_R			FIELD_PREP(CMD_0_ATTR, 0x0)
58 
59 #define CMD_R1_DATA_LENGTH(v)		FIELD_PREP(W1_MASK(63, 48), v)
60 #define CMD_R1_DEF_BYTE(v)		FIELD_PREP(W1_MASK(39, 32), v)
61 #define CMD_R0_TOC				   W0_BIT_(31)
62 #define CMD_R0_ROC				   W0_BIT_(30)
63 #define CMD_R0_RNW				   W0_BIT_(29)
64 #define CMD_R0_MODE(v)			FIELD_PREP(W0_MASK(28, 26), v)
65 #define CMD_R0_DBP				   W0_BIT_(25)
66 #define CMD_R0_DEV_INDEX(v)		FIELD_PREP(W0_MASK(20, 16), v)
67 #define CMD_R0_CP				   W0_BIT_(15)
68 #define CMD_R0_CMD(v)			FIELD_PREP(W0_MASK(14,  7), v)
69 #define CMD_R0_TID(v)			FIELD_PREP(W0_MASK( 6,  3), v)
70 
71 /*
72  * Combo Transfer (Write + Write/Read) Command
73  */
74 
75 #define CMD_0_ATTR_C			FIELD_PREP(CMD_0_ATTR, 0x3)
76 
77 #define CMD_C1_DATA_LENGTH(v)		FIELD_PREP(W1_MASK(63, 48), v)
78 #define CMD_C1_OFFSET(v)		FIELD_PREP(W1_MASK(47, 32), v)
79 #define CMD_C0_TOC				   W0_BIT_(31)
80 #define CMD_C0_ROC				   W0_BIT_(30)
81 #define CMD_C0_RNW				   W0_BIT_(29)
82 #define CMD_C0_MODE(v)			FIELD_PREP(W0_MASK(28, 26), v)
83 #define CMD_C0_16_BIT_SUBOFFSET			   W0_BIT_(25)
84 #define CMD_C0_FIRST_PHASE_MODE			   W0_BIT_(24)
85 #define CMD_C0_DATA_LENGTH_POSITION(v)	FIELD_PREP(W0_MASK(23, 22), v)
86 #define CMD_C0_DEV_INDEX(v)		FIELD_PREP(W0_MASK(20, 16), v)
87 #define CMD_C0_CP				   W0_BIT_(15)
88 #define CMD_C0_CMD(v)			FIELD_PREP(W0_MASK(14,  7), v)
89 #define CMD_C0_TID(v)			FIELD_PREP(W0_MASK( 6,  3), v)
90 
91 /*
92  * Internal Control Command
93  */
94 
95 #define CMD_0_ATTR_M			FIELD_PREP(CMD_0_ATTR, 0x7)
96 
97 #define CMD_M1_VENDOR_SPECIFIC			   W1_MASK(63, 32)
98 #define CMD_M0_MIPI_RESERVED			   W0_MASK(31, 12)
99 #define CMD_M0_MIPI_CMD				   W0_MASK(11,  8)
100 #define CMD_M0_VENDOR_INFO_PRESENT		   W0_BIT_( 7)
101 #define CMD_M0_TID(v)			FIELD_PREP(W0_MASK( 6,  3), v)
102 
103 
104 /* Data Transfer Speed and Mode */
105 enum hci_cmd_mode {
106 	MODE_I3C_SDR0		= 0x0,
107 	MODE_I3C_SDR1		= 0x1,
108 	MODE_I3C_SDR2		= 0x2,
109 	MODE_I3C_SDR3		= 0x3,
110 	MODE_I3C_SDR4		= 0x4,
111 	MODE_I3C_HDR_TSx	= 0x5,
112 	MODE_I3C_HDR_DDR	= 0x6,
113 	MODE_I3C_HDR_BT		= 0x7,
114 	MODE_I3C_Fm_FmP		= 0x8,
115 	MODE_I2C_Fm		= 0x0,
116 	MODE_I2C_FmP		= 0x1,
117 	MODE_I2C_UD1		= 0x2,
118 	MODE_I2C_UD2		= 0x3,
119 	MODE_I2C_UD3		= 0x4,
120 };
121 
122 static enum hci_cmd_mode get_i3c_mode(struct i3c_hci *hci)
123 {
124 	struct i3c_bus *bus = i3c_master_get_bus(&hci->master);
125 
126 	if (bus->scl_rate.i3c >= 12500000)
127 		return MODE_I3C_SDR0;
128 	if (bus->scl_rate.i3c > 8000000)
129 		return MODE_I3C_SDR1;
130 	if (bus->scl_rate.i3c > 6000000)
131 		return MODE_I3C_SDR2;
132 	if (bus->scl_rate.i3c > 4000000)
133 		return MODE_I3C_SDR3;
134 	if (bus->scl_rate.i3c > 2000000)
135 		return MODE_I3C_SDR4;
136 	return MODE_I3C_Fm_FmP;
137 }
138 
139 static enum hci_cmd_mode get_i2c_mode(struct i3c_hci *hci)
140 {
141 	struct i3c_bus *bus = i3c_master_get_bus(&hci->master);
142 
143 	if (bus->scl_rate.i2c >= 1000000)
144 		return MODE_I2C_FmP;
145 	return MODE_I2C_Fm;
146 }
147 
148 static void fill_data_bytes(struct hci_xfer *xfer, u8 *data,
149 			    unsigned int data_len)
150 {
151 	xfer->cmd_desc[1] = 0;
152 	switch (data_len) {
153 	case 4:
154 		xfer->cmd_desc[1] |= CMD_I1_DATA_BYTE_4(data[3]);
155 		fallthrough;
156 	case 3:
157 		xfer->cmd_desc[1] |= CMD_I1_DATA_BYTE_3(data[2]);
158 		fallthrough;
159 	case 2:
160 		xfer->cmd_desc[1] |= CMD_I1_DATA_BYTE_2(data[1]);
161 		fallthrough;
162 	case 1:
163 		xfer->cmd_desc[1] |= CMD_I1_DATA_BYTE_1(data[0]);
164 		fallthrough;
165 	case 0:
166 		break;
167 	}
168 	/* we consumed all the data with the cmd descriptor */
169 	xfer->data = NULL;
170 }
171 
172 static int hci_cmd_v1_prep_ccc(struct i3c_hci *hci,
173 			       struct hci_xfer *xfer,
174 			       u8 ccc_addr, u8 ccc_cmd, bool raw)
175 {
176 	unsigned int dat_idx = 0;
177 	enum hci_cmd_mode mode = get_i3c_mode(hci);
178 	u8 *data = xfer->data;
179 	unsigned int data_len = xfer->data_len;
180 	bool rnw = xfer->rnw;
181 	int ret;
182 
183 	/* this should never happen */
184 	if (WARN_ON(raw))
185 		return -EINVAL;
186 
187 	if (ccc_addr != I3C_BROADCAST_ADDR) {
188 		ret = mipi_i3c_hci_dat_v1.get_index(hci, ccc_addr);
189 		if (ret < 0)
190 			return ret;
191 		dat_idx = ret;
192 	}
193 
194 	xfer->cmd_tid = hci_get_tid();
195 
196 	if (!rnw && data_len <= 4) {
197 		/* we use an Immediate Data Transfer Command */
198 		xfer->cmd_desc[0] =
199 			CMD_0_ATTR_I |
200 			CMD_I0_TID(xfer->cmd_tid) |
201 			CMD_I0_CMD(ccc_cmd) | CMD_I0_CP |
202 			CMD_I0_DEV_INDEX(dat_idx) |
203 			CMD_I0_DTT(data_len) |
204 			CMD_I0_MODE(mode);
205 		fill_data_bytes(xfer, data, data_len);
206 	} else {
207 		/* we use a Regular Data Transfer Command */
208 		xfer->cmd_desc[0] =
209 			CMD_0_ATTR_R |
210 			CMD_R0_TID(xfer->cmd_tid) |
211 			CMD_R0_CMD(ccc_cmd) | CMD_R0_CP |
212 			CMD_R0_DEV_INDEX(dat_idx) |
213 			CMD_R0_MODE(mode) |
214 			(rnw ? CMD_R0_RNW : 0);
215 		xfer->cmd_desc[1] =
216 			CMD_R1_DATA_LENGTH(data_len);
217 	}
218 
219 	return 0;
220 }
221 
222 static void hci_cmd_v1_prep_i3c_xfer(struct i3c_hci *hci,
223 				     struct i3c_dev_desc *dev,
224 				     struct hci_xfer *xfer)
225 {
226 	struct i3c_hci_dev_data *dev_data = i3c_dev_get_master_data(dev);
227 	unsigned int dat_idx = dev_data->dat_idx;
228 	enum hci_cmd_mode mode = get_i3c_mode(hci);
229 	u8 *data = xfer->data;
230 	unsigned int data_len = xfer->data_len;
231 	bool rnw = xfer->rnw;
232 
233 	xfer->cmd_tid = hci_get_tid();
234 
235 	if (!rnw && data_len <= 4) {
236 		/* we use an Immediate Data Transfer Command */
237 		xfer->cmd_desc[0] =
238 			CMD_0_ATTR_I |
239 			CMD_I0_TID(xfer->cmd_tid) |
240 			CMD_I0_DEV_INDEX(dat_idx) |
241 			CMD_I0_DTT(data_len) |
242 			CMD_I0_MODE(mode);
243 		fill_data_bytes(xfer, data, data_len);
244 	} else {
245 		/* we use a Regular Data Transfer Command */
246 		xfer->cmd_desc[0] =
247 			CMD_0_ATTR_R |
248 			CMD_R0_TID(xfer->cmd_tid) |
249 			CMD_R0_DEV_INDEX(dat_idx) |
250 			CMD_R0_MODE(mode) |
251 			(rnw ? CMD_R0_RNW : 0);
252 		xfer->cmd_desc[1] =
253 			CMD_R1_DATA_LENGTH(data_len);
254 	}
255 }
256 
257 static void hci_cmd_v1_prep_i2c_xfer(struct i3c_hci *hci,
258 				     struct i2c_dev_desc *dev,
259 				     struct hci_xfer *xfer)
260 {
261 	struct i3c_hci_dev_data *dev_data = i2c_dev_get_master_data(dev);
262 	unsigned int dat_idx = dev_data->dat_idx;
263 	enum hci_cmd_mode mode = get_i2c_mode(hci);
264 	u8 *data = xfer->data;
265 	unsigned int data_len = xfer->data_len;
266 	bool rnw = xfer->rnw;
267 
268 	xfer->cmd_tid = hci_get_tid();
269 
270 	if (!rnw && data_len <= 4) {
271 		/* we use an Immediate Data Transfer Command */
272 		xfer->cmd_desc[0] =
273 			CMD_0_ATTR_I |
274 			CMD_I0_TID(xfer->cmd_tid) |
275 			CMD_I0_DEV_INDEX(dat_idx) |
276 			CMD_I0_DTT(data_len) |
277 			CMD_I0_MODE(mode);
278 		fill_data_bytes(xfer, data, data_len);
279 	} else {
280 		/* we use a Regular Data Transfer Command */
281 		xfer->cmd_desc[0] =
282 			CMD_0_ATTR_R |
283 			CMD_R0_TID(xfer->cmd_tid) |
284 			CMD_R0_DEV_INDEX(dat_idx) |
285 			CMD_R0_MODE(mode) |
286 			(rnw ? CMD_R0_RNW : 0);
287 		xfer->cmd_desc[1] =
288 			CMD_R1_DATA_LENGTH(data_len);
289 	}
290 }
291 
292 static int hci_cmd_v1_daa(struct i3c_hci *hci)
293 {
294 	struct hci_xfer *xfer;
295 	int ret, dat_idx = -1;
296 	u8 next_addr = 0;
297 	u64 pid;
298 	unsigned int dcr, bcr;
299 	DECLARE_COMPLETION_ONSTACK(done);
300 
301 	xfer = hci_alloc_xfer(2);
302 	if (!xfer)
303 		return -ENOMEM;
304 
305 	/*
306 	 * Simple for now: we allocate a temporary DAT entry, do a single
307 	 * DAA, register the device which will allocate its own DAT entry
308 	 * via the core callback, then free the temporary DAT entry.
309 	 * Loop until there is no more devices to assign an address to.
310 	 * Yes, there is room for improvements.
311 	 */
312 	for (;;) {
313 		ret = mipi_i3c_hci_dat_v1.alloc_entry(hci);
314 		if (ret < 0)
315 			break;
316 		dat_idx = ret;
317 		ret = i3c_master_get_free_addr(&hci->master, next_addr);
318 		if (ret < 0)
319 			break;
320 		next_addr = ret;
321 
322 		DBG("next_addr = 0x%02x, DAA using DAT %d", next_addr, dat_idx);
323 		mipi_i3c_hci_dat_v1.set_dynamic_addr(hci, dat_idx, next_addr);
324 		mipi_i3c_hci_dct_index_reset(hci);
325 
326 		xfer->cmd_tid = hci_get_tid();
327 		xfer->cmd_desc[0] =
328 			CMD_0_ATTR_A |
329 			CMD_A0_TID(xfer->cmd_tid) |
330 			CMD_A0_CMD(I3C_CCC_ENTDAA) |
331 			CMD_A0_DEV_INDEX(dat_idx) |
332 			CMD_A0_DEV_COUNT(1) |
333 			CMD_A0_ROC | CMD_A0_TOC;
334 		xfer->cmd_desc[1] = 0;
335 		hci->io->queue_xfer(hci, xfer, 1);
336 		if (!wait_for_completion_timeout(&done, HZ) &&
337 		    hci->io->dequeue_xfer(hci, xfer, 1)) {
338 			ret = -ETIME;
339 			break;
340 		}
341 		if (RESP_STATUS(xfer[0].response) == RESP_ERR_NACK &&
342 		    RESP_STATUS(xfer[0].response) == 1) {
343 			ret = 0;  /* no more devices to be assigned */
344 			break;
345 		}
346 		if (RESP_STATUS(xfer[0].response) != RESP_SUCCESS) {
347 			ret = -EIO;
348 			break;
349 		}
350 
351 		i3c_hci_dct_get_val(hci, 0, &pid, &dcr, &bcr);
352 		DBG("assigned address %#x to device PID=0x%llx DCR=%#x BCR=%#x",
353 		    next_addr, pid, dcr, bcr);
354 
355 		mipi_i3c_hci_dat_v1.free_entry(hci, dat_idx);
356 		dat_idx = -1;
357 
358 		/*
359 		 * TODO: Extend the subsystem layer to allow for registering
360 		 * new device and provide BCR/DCR/PID at the same time.
361 		 */
362 		ret = i3c_master_add_i3c_dev_locked(&hci->master, next_addr);
363 		if (ret)
364 			break;
365 	}
366 
367 	if (dat_idx >= 0)
368 		mipi_i3c_hci_dat_v1.free_entry(hci, dat_idx);
369 	hci_free_xfer(xfer, 1);
370 	return ret;
371 }
372 
373 const struct hci_cmd_ops mipi_i3c_hci_cmd_v1 = {
374 	.prep_ccc		= hci_cmd_v1_prep_ccc,
375 	.prep_i3c_xfer		= hci_cmd_v1_prep_i3c_xfer,
376 	.prep_i2c_xfer		= hci_cmd_v1_prep_i2c_xfer,
377 	.perform_daa		= hci_cmd_v1_daa,
378 };
379