xref: /linux/drivers/i3c/master/svc-i3c-master.c (revision a2604f8d43bf414db54c42ca6ea52803ce1c0b2f)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Silvaco dual-role I3C master driver
4  *
5  * Copyright (C) 2020 Silvaco
6  * Author: Miquel RAYNAL <miquel.raynal@bootlin.com>
7  * Based on a work from: Conor Culhane <conor.culhane@silvaco.com>
8  */
9 
10 #include <linux/bitfield.h>
11 #include <linux/clk.h>
12 #include <linux/completion.h>
13 #include <linux/errno.h>
14 #include <linux/i3c/master.h>
15 #include <linux/interrupt.h>
16 #include <linux/iopoll.h>
17 #include <linux/list.h>
18 #include <linux/module.h>
19 #include <linux/of.h>
20 #include <linux/pinctrl/consumer.h>
21 #include <linux/platform_device.h>
22 #include <linux/pm_runtime.h>
23 
24 /* Master Mode Registers */
25 #define SVC_I3C_MCONFIG      0x000
26 #define   SVC_I3C_MCONFIG_MASTER_EN BIT(0)
27 #define   SVC_I3C_MCONFIG_DISTO(x) FIELD_PREP(BIT(3), (x))
28 #define   SVC_I3C_MCONFIG_HKEEP(x) FIELD_PREP(GENMASK(5, 4), (x))
29 #define   SVC_I3C_MCONFIG_ODSTOP(x) FIELD_PREP(BIT(6), (x))
30 #define   SVC_I3C_MCONFIG_PPBAUD(x) FIELD_PREP(GENMASK(11, 8), (x))
31 #define   SVC_I3C_MCONFIG_PPLOW(x) FIELD_PREP(GENMASK(15, 12), (x))
32 #define   SVC_I3C_MCONFIG_ODBAUD(x) FIELD_PREP(GENMASK(23, 16), (x))
33 #define   SVC_I3C_MCONFIG_ODHPP(x) FIELD_PREP(BIT(24), (x))
34 #define   SVC_I3C_MCONFIG_SKEW(x) FIELD_PREP(GENMASK(27, 25), (x))
35 #define   SVC_I3C_MCONFIG_SKEW_MASK GENMASK(27, 25)
36 #define   SVC_I3C_MCONFIG_I2CBAUD(x) FIELD_PREP(GENMASK(31, 28), (x))
37 
38 #define SVC_I3C_MCTRL        0x084
39 #define   SVC_I3C_MCTRL_REQUEST_MASK GENMASK(2, 0)
40 #define   SVC_I3C_MCTRL_REQUEST_NONE 0
41 #define   SVC_I3C_MCTRL_REQUEST_START_ADDR 1
42 #define   SVC_I3C_MCTRL_REQUEST_STOP 2
43 #define   SVC_I3C_MCTRL_REQUEST_IBI_ACKNACK 3
44 #define   SVC_I3C_MCTRL_REQUEST_PROC_DAA 4
45 #define   SVC_I3C_MCTRL_REQUEST_AUTO_IBI 7
46 #define   SVC_I3C_MCTRL_TYPE_I3C 0
47 #define   SVC_I3C_MCTRL_TYPE_I2C BIT(4)
48 #define   SVC_I3C_MCTRL_IBIRESP_AUTO 0
49 #define   SVC_I3C_MCTRL_IBIRESP_ACK_WITHOUT_BYTE 0
50 #define   SVC_I3C_MCTRL_IBIRESP_ACK_WITH_BYTE BIT(7)
51 #define   SVC_I3C_MCTRL_IBIRESP_NACK BIT(6)
52 #define   SVC_I3C_MCTRL_IBIRESP_MANUAL GENMASK(7, 6)
53 #define   SVC_I3C_MCTRL_DIR(x) FIELD_PREP(BIT(8), (x))
54 #define   SVC_I3C_MCTRL_DIR_WRITE 0
55 #define   SVC_I3C_MCTRL_DIR_READ 1
56 #define   SVC_I3C_MCTRL_ADDR(x) FIELD_PREP(GENMASK(15, 9), (x))
57 #define   SVC_I3C_MCTRL_RDTERM(x) FIELD_PREP(GENMASK(23, 16), (x))
58 
59 #define SVC_I3C_MSTATUS      0x088
60 #define   SVC_I3C_MSTATUS_STATE(x) FIELD_GET(GENMASK(2, 0), (x))
61 #define   SVC_I3C_MSTATUS_STATE_DAA(x) (SVC_I3C_MSTATUS_STATE(x) == 5)
62 #define   SVC_I3C_MSTATUS_STATE_SLVREQ(x) (SVC_I3C_MSTATUS_STATE(x) == 1)
63 #define   SVC_I3C_MSTATUS_STATE_IDLE(x) (SVC_I3C_MSTATUS_STATE(x) == 0)
64 #define   SVC_I3C_MSTATUS_BETWEEN(x) FIELD_GET(BIT(4), (x))
65 #define   SVC_I3C_MSTATUS_NACKED(x) FIELD_GET(BIT(5), (x))
66 #define   SVC_I3C_MSTATUS_IBITYPE(x) FIELD_GET(GENMASK(7, 6), (x))
67 #define   SVC_I3C_MSTATUS_IBITYPE_IBI 1
68 #define   SVC_I3C_MSTATUS_IBITYPE_MASTER_REQUEST 2
69 #define   SVC_I3C_MSTATUS_IBITYPE_HOT_JOIN 3
70 #define   SVC_I3C_MINT_SLVSTART BIT(8)
71 #define   SVC_I3C_MINT_MCTRLDONE BIT(9)
72 #define   SVC_I3C_MINT_COMPLETE BIT(10)
73 #define   SVC_I3C_MINT_RXPEND BIT(11)
74 #define   SVC_I3C_MINT_TXNOTFULL BIT(12)
75 #define   SVC_I3C_MINT_IBIWON BIT(13)
76 #define   SVC_I3C_MINT_ERRWARN BIT(15)
77 #define   SVC_I3C_MSTATUS_SLVSTART(x) FIELD_GET(SVC_I3C_MINT_SLVSTART, (x))
78 #define   SVC_I3C_MSTATUS_MCTRLDONE(x) FIELD_GET(SVC_I3C_MINT_MCTRLDONE, (x))
79 #define   SVC_I3C_MSTATUS_COMPLETE(x) FIELD_GET(SVC_I3C_MINT_COMPLETE, (x))
80 #define   SVC_I3C_MSTATUS_RXPEND(x) FIELD_GET(SVC_I3C_MINT_RXPEND, (x))
81 #define   SVC_I3C_MSTATUS_TXNOTFULL(x) FIELD_GET(SVC_I3C_MINT_TXNOTFULL, (x))
82 #define   SVC_I3C_MSTATUS_IBIWON(x) FIELD_GET(SVC_I3C_MINT_IBIWON, (x))
83 #define   SVC_I3C_MSTATUS_ERRWARN(x) FIELD_GET(SVC_I3C_MINT_ERRWARN, (x))
84 #define   SVC_I3C_MSTATUS_IBIADDR(x) FIELD_GET(GENMASK(30, 24), (x))
85 
86 #define SVC_I3C_IBIRULES     0x08C
87 #define   SVC_I3C_IBIRULES_ADDR(slot, addr) FIELD_PREP(GENMASK(29, 0), \
88 						       ((addr) & 0x3F) << ((slot) * 6))
89 #define   SVC_I3C_IBIRULES_ADDRS 5
90 #define   SVC_I3C_IBIRULES_MSB0 BIT(30)
91 #define   SVC_I3C_IBIRULES_NOBYTE BIT(31)
92 #define   SVC_I3C_IBIRULES_MANDBYTE 0
93 #define SVC_I3C_MINTSET      0x090
94 #define SVC_I3C_MINTCLR      0x094
95 #define SVC_I3C_MINTMASKED   0x098
96 #define SVC_I3C_MERRWARN     0x09C
97 #define   SVC_I3C_MERRWARN_NACK BIT(2)
98 #define   SVC_I3C_MERRWARN_TIMEOUT BIT(20)
99 #define SVC_I3C_MDMACTRL     0x0A0
100 #define SVC_I3C_MDATACTRL    0x0AC
101 #define   SVC_I3C_MDATACTRL_FLUSHTB BIT(0)
102 #define   SVC_I3C_MDATACTRL_FLUSHRB BIT(1)
103 #define   SVC_I3C_MDATACTRL_UNLOCK_TRIG BIT(3)
104 #define   SVC_I3C_MDATACTRL_TXTRIG_FIFO_NOT_FULL GENMASK(5, 4)
105 #define   SVC_I3C_MDATACTRL_RXTRIG_FIFO_NOT_EMPTY 0
106 #define   SVC_I3C_MDATACTRL_RXCOUNT(x) FIELD_GET(GENMASK(28, 24), (x))
107 #define   SVC_I3C_MDATACTRL_TXFULL BIT(30)
108 #define   SVC_I3C_MDATACTRL_RXEMPTY BIT(31)
109 
110 #define SVC_I3C_MWDATAB      0x0B0
111 #define   SVC_I3C_MWDATAB_END BIT(8)
112 
113 #define SVC_I3C_MWDATABE     0x0B4
114 #define SVC_I3C_MWDATAH      0x0B8
115 #define SVC_I3C_MWDATAHE     0x0BC
116 #define SVC_I3C_MRDATAB      0x0C0
117 #define SVC_I3C_MRDATAH      0x0C8
118 #define SVC_I3C_MWDATAB1     0x0CC
119 #define SVC_I3C_MWMSG_SDR    0x0D0
120 #define SVC_I3C_MRMSG_SDR    0x0D4
121 #define SVC_I3C_MWMSG_DDR    0x0D8
122 #define SVC_I3C_MRMSG_DDR    0x0DC
123 
124 #define SVC_I3C_MDYNADDR     0x0E4
125 #define   SVC_MDYNADDR_VALID BIT(0)
126 #define   SVC_MDYNADDR_ADDR(x) FIELD_PREP(GENMASK(7, 1), (x))
127 
128 #define SVC_I3C_MAX_DEVS 32
129 #define SVC_I3C_PM_TIMEOUT_MS 1000
130 
131 /* This parameter depends on the implementation and may be tuned */
132 #define SVC_I3C_FIFO_SIZE 16
133 #define SVC_I3C_PPBAUD_MAX 15
134 #define SVC_I3C_QUICK_I2C_CLK 4170000
135 
136 #define SVC_I3C_EVENT_IBI	GENMASK(7, 0)
137 #define SVC_I3C_EVENT_HOTJOIN	BIT(31)
138 
139 /*
140  * SVC_I3C_QUIRK_FIFO_EMPTY:
141  * I3C HW stalls the write transfer if the transmit FIFO becomes empty,
142  * when new data is written to FIFO, I3C HW resumes the transfer but
143  * the first transmitted data bit may have the wrong value.
144  * Workaround:
145  * Fill the FIFO in advance to prevent FIFO from becoming empty.
146  */
147 #define SVC_I3C_QUIRK_FIFO_EMPTY	BIT(0)
148 /*
149  * SVC_I3C_QUIRK_FLASE_SLVSTART:
150  * I3C HW may generate an invalid SlvStart event when emitting a STOP.
151  * If it is a true SlvStart, the MSTATUS state is SLVREQ.
152  */
153 #define SVC_I3C_QUIRK_FALSE_SLVSTART	BIT(1)
154 /*
155  * SVC_I3C_QUIRK_DAA_CORRUPT:
156  * When MCONFIG.SKEW=0 and MCONFIG.ODHPP=0, the ENTDAA transaction gets
157  * corrupted and results in a no repeated-start condition at the end of
158  * address assignment.
159  * Workaround:
160  * Set MCONFIG.SKEW to 1 before initiating the DAA process. After the DAA
161  * process is completed, return MCONFIG.SKEW to its previous value.
162  */
163 #define SVC_I3C_QUIRK_DAA_CORRUPT	BIT(2)
164 
165 struct svc_i3c_cmd {
166 	u8 addr;
167 	bool rnw;
168 	u8 *in;
169 	const void *out;
170 	unsigned int len;
171 	unsigned int actual_len;
172 	struct i3c_priv_xfer *xfer;
173 	bool continued;
174 };
175 
176 struct svc_i3c_xfer {
177 	struct list_head node;
178 	struct completion comp;
179 	int ret;
180 	unsigned int type;
181 	unsigned int ncmds;
182 	struct svc_i3c_cmd cmds[] __counted_by(ncmds);
183 };
184 
185 struct svc_i3c_regs_save {
186 	u32 mconfig;
187 	u32 mdynaddr;
188 };
189 
190 struct svc_i3c_drvdata {
191 	u32 quirks;
192 };
193 
194 /**
195  * struct svc_i3c_master - Silvaco I3C Master structure
196  * @base: I3C master controller
197  * @dev: Corresponding device
198  * @regs: Memory mapping
199  * @saved_regs: Volatile values for PM operations
200  * @free_slots: Bit array of available slots
201  * @addrs: Array containing the dynamic addresses of each attached device
202  * @descs: Array of descriptors, one per attached device
203  * @hj_work: Hot-join work
204  * @irq: Main interrupt
205  * @num_clks: I3C clock number
206  * @fclk: Fast clock (bus)
207  * @clks: I3C clock array
208  * @xferqueue: Transfer queue structure
209  * @xferqueue.list: List member
210  * @xferqueue.cur: Current ongoing transfer
211  * @xferqueue.lock: Queue lock
212  * @ibi: IBI structure
213  * @ibi.num_slots: Number of slots available in @ibi.slots
214  * @ibi.slots: Available IBI slots
215  * @ibi.tbq_slot: To be queued IBI slot
216  * @ibi.lock: IBI lock
217  * @lock: Transfer lock, protect between IBI work thread and callbacks from master
218  * @drvdata: Driver data
219  * @enabled_events: Bit masks for enable events (IBI, HotJoin).
220  * @mctrl_config: Configuration value in SVC_I3C_MCTRL for setting speed back.
221  */
222 struct svc_i3c_master {
223 	struct i3c_master_controller base;
224 	struct device *dev;
225 	void __iomem *regs;
226 	struct svc_i3c_regs_save saved_regs;
227 	u32 free_slots;
228 	u8 addrs[SVC_I3C_MAX_DEVS];
229 	struct i3c_dev_desc *descs[SVC_I3C_MAX_DEVS];
230 	struct work_struct hj_work;
231 	int irq;
232 	int num_clks;
233 	struct clk *fclk;
234 	struct clk_bulk_data *clks;
235 	struct {
236 		struct list_head list;
237 		struct svc_i3c_xfer *cur;
238 		/* Prevent races between transfers */
239 		spinlock_t lock;
240 	} xferqueue;
241 	struct {
242 		unsigned int num_slots;
243 		struct i3c_dev_desc **slots;
244 		struct i3c_ibi_slot *tbq_slot;
245 		/* Prevent races within IBI handlers */
246 		spinlock_t lock;
247 	} ibi;
248 	struct mutex lock;
249 	const struct svc_i3c_drvdata *drvdata;
250 	u32 enabled_events;
251 	u32 mctrl_config;
252 };
253 
254 /**
255  * struct svc_i3c_i2c_dev_data - Device specific data
256  * @index: Index in the master tables corresponding to this device
257  * @ibi: IBI slot index in the master structure
258  * @ibi_pool: IBI pool associated to this device
259  */
260 struct svc_i3c_i2c_dev_data {
261 	u8 index;
262 	int ibi;
263 	struct i3c_generic_ibi_pool *ibi_pool;
264 };
265 
svc_has_quirk(struct svc_i3c_master * master,u32 quirk)266 static inline bool svc_has_quirk(struct svc_i3c_master *master, u32 quirk)
267 {
268 	return (master->drvdata->quirks & quirk);
269 }
270 
svc_has_daa_corrupt(struct svc_i3c_master * master)271 static inline bool svc_has_daa_corrupt(struct svc_i3c_master *master)
272 {
273 	return ((master->drvdata->quirks & SVC_I3C_QUIRK_DAA_CORRUPT) &&
274 		!(master->mctrl_config &
275 		(SVC_I3C_MCONFIG_SKEW_MASK | SVC_I3C_MCONFIG_ODHPP(1))));
276 }
277 
is_events_enabled(struct svc_i3c_master * master,u32 mask)278 static inline bool is_events_enabled(struct svc_i3c_master *master, u32 mask)
279 {
280 	return !!(master->enabled_events & mask);
281 }
282 
svc_i3c_master_error(struct svc_i3c_master * master)283 static bool svc_i3c_master_error(struct svc_i3c_master *master)
284 {
285 	u32 mstatus, merrwarn;
286 
287 	mstatus = readl(master->regs + SVC_I3C_MSTATUS);
288 	if (SVC_I3C_MSTATUS_ERRWARN(mstatus)) {
289 		merrwarn = readl(master->regs + SVC_I3C_MERRWARN);
290 		writel(merrwarn, master->regs + SVC_I3C_MERRWARN);
291 
292 		/* Ignore timeout error */
293 		if (merrwarn & SVC_I3C_MERRWARN_TIMEOUT) {
294 			dev_dbg(master->dev, "Warning condition: MSTATUS 0x%08x, MERRWARN 0x%08x\n",
295 				mstatus, merrwarn);
296 			return false;
297 		}
298 
299 		dev_err(master->dev,
300 			"Error condition: MSTATUS 0x%08x, MERRWARN 0x%08x\n",
301 			mstatus, merrwarn);
302 
303 		return true;
304 	}
305 
306 	return false;
307 }
308 
svc_i3c_master_enable_interrupts(struct svc_i3c_master * master,u32 mask)309 static void svc_i3c_master_enable_interrupts(struct svc_i3c_master *master, u32 mask)
310 {
311 	writel(mask, master->regs + SVC_I3C_MINTSET);
312 }
313 
svc_i3c_master_disable_interrupts(struct svc_i3c_master * master)314 static void svc_i3c_master_disable_interrupts(struct svc_i3c_master *master)
315 {
316 	u32 mask = readl(master->regs + SVC_I3C_MINTSET);
317 
318 	writel(mask, master->regs + SVC_I3C_MINTCLR);
319 }
320 
svc_i3c_master_clear_merrwarn(struct svc_i3c_master * master)321 static void svc_i3c_master_clear_merrwarn(struct svc_i3c_master *master)
322 {
323 	/* Clear pending warnings */
324 	writel(readl(master->regs + SVC_I3C_MERRWARN),
325 	       master->regs + SVC_I3C_MERRWARN);
326 }
327 
svc_i3c_master_flush_fifo(struct svc_i3c_master * master)328 static void svc_i3c_master_flush_fifo(struct svc_i3c_master *master)
329 {
330 	/* Flush FIFOs */
331 	writel(SVC_I3C_MDATACTRL_FLUSHTB | SVC_I3C_MDATACTRL_FLUSHRB,
332 	       master->regs + SVC_I3C_MDATACTRL);
333 }
334 
svc_i3c_master_reset_fifo_trigger(struct svc_i3c_master * master)335 static void svc_i3c_master_reset_fifo_trigger(struct svc_i3c_master *master)
336 {
337 	u32 reg;
338 
339 	/* Set RX and TX tigger levels, flush FIFOs */
340 	reg = SVC_I3C_MDATACTRL_FLUSHTB |
341 	      SVC_I3C_MDATACTRL_FLUSHRB |
342 	      SVC_I3C_MDATACTRL_UNLOCK_TRIG |
343 	      SVC_I3C_MDATACTRL_TXTRIG_FIFO_NOT_FULL |
344 	      SVC_I3C_MDATACTRL_RXTRIG_FIFO_NOT_EMPTY;
345 	writel(reg, master->regs + SVC_I3C_MDATACTRL);
346 }
347 
svc_i3c_master_reset(struct svc_i3c_master * master)348 static void svc_i3c_master_reset(struct svc_i3c_master *master)
349 {
350 	svc_i3c_master_clear_merrwarn(master);
351 	svc_i3c_master_reset_fifo_trigger(master);
352 	svc_i3c_master_disable_interrupts(master);
353 }
354 
355 static inline struct svc_i3c_master *
to_svc_i3c_master(struct i3c_master_controller * master)356 to_svc_i3c_master(struct i3c_master_controller *master)
357 {
358 	return container_of(master, struct svc_i3c_master, base);
359 }
360 
svc_i3c_master_hj_work(struct work_struct * work)361 static void svc_i3c_master_hj_work(struct work_struct *work)
362 {
363 	struct svc_i3c_master *master;
364 
365 	master = container_of(work, struct svc_i3c_master, hj_work);
366 	i3c_master_do_daa(&master->base);
367 }
368 
369 static struct i3c_dev_desc *
svc_i3c_master_dev_from_addr(struct svc_i3c_master * master,unsigned int ibiaddr)370 svc_i3c_master_dev_from_addr(struct svc_i3c_master *master,
371 			     unsigned int ibiaddr)
372 {
373 	int i;
374 
375 	for (i = 0; i < SVC_I3C_MAX_DEVS; i++)
376 		if (master->addrs[i] == ibiaddr)
377 			break;
378 
379 	if (i == SVC_I3C_MAX_DEVS)
380 		return NULL;
381 
382 	return master->descs[i];
383 }
384 
svc_i3c_master_emit_stop(struct svc_i3c_master * master)385 static void svc_i3c_master_emit_stop(struct svc_i3c_master *master)
386 {
387 	writel(SVC_I3C_MCTRL_REQUEST_STOP, master->regs + SVC_I3C_MCTRL);
388 
389 	/*
390 	 * This delay is necessary after the emission of a stop, otherwise eg.
391 	 * repeating IBIs do not get detected. There is a note in the manual
392 	 * about it, stating that the stop condition might not be settled
393 	 * correctly if a start condition follows too rapidly.
394 	 */
395 	udelay(1);
396 }
397 
svc_i3c_master_handle_ibi(struct svc_i3c_master * master,struct i3c_dev_desc * dev)398 static int svc_i3c_master_handle_ibi(struct svc_i3c_master *master,
399 				     struct i3c_dev_desc *dev)
400 {
401 	struct svc_i3c_i2c_dev_data *data = i3c_dev_get_master_data(dev);
402 	struct i3c_ibi_slot *slot;
403 	unsigned int count;
404 	u32 mdatactrl;
405 	int ret, val;
406 	u8 *buf;
407 
408 	slot = i3c_generic_ibi_get_free_slot(data->ibi_pool);
409 	if (!slot)
410 		return -ENOSPC;
411 
412 	slot->len = 0;
413 	buf = slot->data;
414 
415 	ret = readl_relaxed_poll_timeout(master->regs + SVC_I3C_MSTATUS, val,
416 						SVC_I3C_MSTATUS_COMPLETE(val), 0, 1000);
417 	if (ret) {
418 		dev_err(master->dev, "Timeout when polling for COMPLETE\n");
419 		return ret;
420 	}
421 
422 	while (SVC_I3C_MSTATUS_RXPEND(readl(master->regs + SVC_I3C_MSTATUS))  &&
423 	       slot->len < SVC_I3C_FIFO_SIZE) {
424 		mdatactrl = readl(master->regs + SVC_I3C_MDATACTRL);
425 		count = SVC_I3C_MDATACTRL_RXCOUNT(mdatactrl);
426 		readsb(master->regs + SVC_I3C_MRDATAB, buf, count);
427 		slot->len += count;
428 		buf += count;
429 	}
430 
431 	master->ibi.tbq_slot = slot;
432 
433 	return 0;
434 }
435 
svc_i3c_master_ack_ibi(struct svc_i3c_master * master,bool mandatory_byte)436 static int svc_i3c_master_ack_ibi(struct svc_i3c_master *master,
437 				   bool mandatory_byte)
438 {
439 	unsigned int ibi_ack_nack;
440 	u32 reg;
441 
442 	ibi_ack_nack = SVC_I3C_MCTRL_REQUEST_IBI_ACKNACK;
443 	if (mandatory_byte)
444 		ibi_ack_nack |= SVC_I3C_MCTRL_IBIRESP_ACK_WITH_BYTE;
445 	else
446 		ibi_ack_nack |= SVC_I3C_MCTRL_IBIRESP_ACK_WITHOUT_BYTE;
447 
448 	writel(ibi_ack_nack, master->regs + SVC_I3C_MCTRL);
449 
450 	return readl_poll_timeout_atomic(master->regs + SVC_I3C_MSTATUS, reg,
451 					 SVC_I3C_MSTATUS_MCTRLDONE(reg), 1, 1000);
452 
453 }
454 
svc_i3c_master_nack_ibi(struct svc_i3c_master * master)455 static int svc_i3c_master_nack_ibi(struct svc_i3c_master *master)
456 {
457 	int ret;
458 	u32 reg;
459 
460 	writel(SVC_I3C_MCTRL_REQUEST_IBI_ACKNACK |
461 	       SVC_I3C_MCTRL_IBIRESP_NACK,
462 	       master->regs + SVC_I3C_MCTRL);
463 
464 	ret = readl_poll_timeout_atomic(master->regs + SVC_I3C_MSTATUS, reg,
465 					SVC_I3C_MSTATUS_MCTRLDONE(reg), 1, 1000);
466 	return ret;
467 }
468 
svc_i3c_master_handle_ibi_won(struct svc_i3c_master * master,u32 mstatus)469 static int svc_i3c_master_handle_ibi_won(struct svc_i3c_master *master, u32 mstatus)
470 {
471 	u32 ibitype;
472 	int ret = 0;
473 
474 	ibitype = SVC_I3C_MSTATUS_IBITYPE(mstatus);
475 
476 	writel(SVC_I3C_MINT_IBIWON, master->regs + SVC_I3C_MSTATUS);
477 
478 	/* Hardware can't auto emit NACK for hot join and master request */
479 	switch (ibitype) {
480 	case SVC_I3C_MSTATUS_IBITYPE_HOT_JOIN:
481 	case SVC_I3C_MSTATUS_IBITYPE_MASTER_REQUEST:
482 		ret = svc_i3c_master_nack_ibi(master);
483 	}
484 
485 	return ret;
486 }
487 
svc_i3c_master_ibi_isr(struct svc_i3c_master * master)488 static void svc_i3c_master_ibi_isr(struct svc_i3c_master *master)
489 {
490 	struct svc_i3c_i2c_dev_data *data;
491 	unsigned int ibitype, ibiaddr;
492 	struct i3c_dev_desc *dev;
493 	u32 status, val;
494 	int ret;
495 
496 	/*
497 	 * According to I3C spec ver 1.1, 09-Jun-2021, section 5.1.2.5:
498 	 *
499 	 * The I3C Controller shall hold SCL low while the Bus is in ACK/NACK Phase of I3C/I2C
500 	 * transfer. But maximum stall time is 100us. The IRQs have to be disabled to prevent
501 	 * schedule during the whole I3C transaction, otherwise, the I3C bus timeout may happen if
502 	 * any irq or schedule happen during transaction.
503 	 */
504 	guard(spinlock)(&master->xferqueue.lock);
505 
506 	/*
507 	 * IBIWON may be set before SVC_I3C_MCTRL_REQUEST_AUTO_IBI, causing
508 	 * readl_relaxed_poll_timeout() to return immediately. Consequently,
509 	 * ibitype will be 0 since it was last updated only after the 8th SCL
510 	 * cycle, leading to missed client IBI handlers.
511 	 *
512 	 * A typical scenario is when IBIWON occurs and bus arbitration is lost
513 	 * at svc_i3c_master_priv_xfers().
514 	 *
515 	 * Clear SVC_I3C_MINT_IBIWON before sending SVC_I3C_MCTRL_REQUEST_AUTO_IBI.
516 	 */
517 	writel(SVC_I3C_MINT_IBIWON, master->regs + SVC_I3C_MSTATUS);
518 
519 	/* Acknowledge the incoming interrupt with the AUTOIBI mechanism */
520 	writel(SVC_I3C_MCTRL_REQUEST_AUTO_IBI |
521 	       SVC_I3C_MCTRL_IBIRESP_AUTO,
522 	       master->regs + SVC_I3C_MCTRL);
523 
524 	/* Wait for IBIWON, should take approximately 100us */
525 	ret = readl_relaxed_poll_timeout_atomic(master->regs + SVC_I3C_MSTATUS, val,
526 					 SVC_I3C_MSTATUS_IBIWON(val), 0, 100);
527 	if (ret) {
528 		dev_err(master->dev, "Timeout when polling for IBIWON\n");
529 		svc_i3c_master_emit_stop(master);
530 		return;
531 	}
532 
533 	status = readl(master->regs + SVC_I3C_MSTATUS);
534 	ibitype = SVC_I3C_MSTATUS_IBITYPE(status);
535 	ibiaddr = SVC_I3C_MSTATUS_IBIADDR(status);
536 
537 	/* Handle the critical responses to IBI's */
538 	switch (ibitype) {
539 	case SVC_I3C_MSTATUS_IBITYPE_IBI:
540 		dev = svc_i3c_master_dev_from_addr(master, ibiaddr);
541 		if (!dev || !is_events_enabled(master, SVC_I3C_EVENT_IBI))
542 			svc_i3c_master_nack_ibi(master);
543 		else
544 			svc_i3c_master_handle_ibi(master, dev);
545 		break;
546 	case SVC_I3C_MSTATUS_IBITYPE_HOT_JOIN:
547 		if (is_events_enabled(master, SVC_I3C_EVENT_HOTJOIN))
548 			svc_i3c_master_ack_ibi(master, false);
549 		else
550 			svc_i3c_master_nack_ibi(master);
551 		break;
552 	case SVC_I3C_MSTATUS_IBITYPE_MASTER_REQUEST:
553 		svc_i3c_master_nack_ibi(master);
554 		break;
555 	default:
556 		break;
557 	}
558 
559 	/*
560 	 * If an error happened, we probably got interrupted and the exchange
561 	 * timedout. In this case we just drop everything, emit a stop and wait
562 	 * for the slave to interrupt again.
563 	 */
564 	if (svc_i3c_master_error(master)) {
565 		if (master->ibi.tbq_slot) {
566 			data = i3c_dev_get_master_data(dev);
567 			i3c_generic_ibi_recycle_slot(data->ibi_pool,
568 						     master->ibi.tbq_slot);
569 			master->ibi.tbq_slot = NULL;
570 		}
571 
572 		svc_i3c_master_emit_stop(master);
573 
574 		return;
575 	}
576 
577 	/* Handle the non critical tasks */
578 	switch (ibitype) {
579 	case SVC_I3C_MSTATUS_IBITYPE_IBI:
580 		svc_i3c_master_emit_stop(master);
581 		if (dev) {
582 			i3c_master_queue_ibi(dev, master->ibi.tbq_slot);
583 			master->ibi.tbq_slot = NULL;
584 		}
585 		break;
586 	case SVC_I3C_MSTATUS_IBITYPE_HOT_JOIN:
587 		svc_i3c_master_emit_stop(master);
588 		if (is_events_enabled(master, SVC_I3C_EVENT_HOTJOIN))
589 			queue_work(master->base.wq, &master->hj_work);
590 		break;
591 	case SVC_I3C_MSTATUS_IBITYPE_MASTER_REQUEST:
592 		svc_i3c_master_emit_stop(master);
593 		break;
594 	default:
595 		break;
596 	}
597 }
598 
svc_i3c_master_irq_handler(int irq,void * dev_id)599 static irqreturn_t svc_i3c_master_irq_handler(int irq, void *dev_id)
600 {
601 	struct svc_i3c_master *master = (struct svc_i3c_master *)dev_id;
602 	u32 active = readl(master->regs + SVC_I3C_MSTATUS);
603 
604 	if (!SVC_I3C_MSTATUS_SLVSTART(active))
605 		return IRQ_NONE;
606 
607 	/* Clear the interrupt status */
608 	writel(SVC_I3C_MINT_SLVSTART, master->regs + SVC_I3C_MSTATUS);
609 
610 	/* Ignore the false event */
611 	if (svc_has_quirk(master, SVC_I3C_QUIRK_FALSE_SLVSTART) &&
612 	    !SVC_I3C_MSTATUS_STATE_SLVREQ(active))
613 		return IRQ_HANDLED;
614 
615 	/*
616 	 * The SDA line remains low until the request is processed.
617 	 * Receive the request in the interrupt context to respond promptly
618 	 * and restore the bus to idle state.
619 	 */
620 	svc_i3c_master_ibi_isr(master);
621 
622 	return IRQ_HANDLED;
623 }
624 
svc_i3c_master_set_speed(struct i3c_master_controller * m,enum i3c_open_drain_speed speed)625 static int svc_i3c_master_set_speed(struct i3c_master_controller *m,
626 				     enum i3c_open_drain_speed speed)
627 {
628 	struct svc_i3c_master *master = to_svc_i3c_master(m);
629 	struct i3c_bus *bus = i3c_master_get_bus(&master->base);
630 	u32 ppbaud, odbaud, odhpp, mconfig;
631 	unsigned long fclk_rate;
632 	int ret;
633 
634 	ret = pm_runtime_resume_and_get(master->dev);
635 	if (ret < 0) {
636 		dev_err(master->dev, "<%s> Cannot get runtime PM.\n", __func__);
637 		return ret;
638 	}
639 
640 	switch (speed) {
641 	case I3C_OPEN_DRAIN_SLOW_SPEED:
642 		fclk_rate = clk_get_rate(master->fclk);
643 		if (!fclk_rate) {
644 			ret = -EINVAL;
645 			goto rpm_out;
646 		}
647 		/*
648 		 * Set 50% duty-cycle I2C speed to I3C OPEN-DRAIN mode, so the first
649 		 * broadcast address is visible to all I2C/I3C devices on the I3C bus.
650 		 * I3C device working as a I2C device will turn off its 50ns Spike
651 		 * Filter to change to I3C mode.
652 		 */
653 		mconfig = master->mctrl_config;
654 		ppbaud = FIELD_GET(GENMASK(11, 8), mconfig);
655 		odhpp = 0;
656 		odbaud = DIV_ROUND_UP(fclk_rate, bus->scl_rate.i2c * (2 + 2 * ppbaud)) - 1;
657 		mconfig &= ~GENMASK(24, 16);
658 		mconfig |= SVC_I3C_MCONFIG_ODBAUD(odbaud) | SVC_I3C_MCONFIG_ODHPP(odhpp);
659 		writel(mconfig, master->regs + SVC_I3C_MCONFIG);
660 		break;
661 	case I3C_OPEN_DRAIN_NORMAL_SPEED:
662 		writel(master->mctrl_config, master->regs + SVC_I3C_MCONFIG);
663 		break;
664 	}
665 
666 rpm_out:
667 	pm_runtime_mark_last_busy(master->dev);
668 	pm_runtime_put_autosuspend(master->dev);
669 
670 	return ret;
671 }
672 
svc_i3c_master_bus_init(struct i3c_master_controller * m)673 static int svc_i3c_master_bus_init(struct i3c_master_controller *m)
674 {
675 	struct svc_i3c_master *master = to_svc_i3c_master(m);
676 	struct i3c_bus *bus = i3c_master_get_bus(m);
677 	struct i3c_device_info info = {};
678 	unsigned long fclk_rate, fclk_period_ns;
679 	unsigned long i2c_period_ns, i2c_scl_rate, i3c_scl_rate;
680 	unsigned int high_period_ns, od_low_period_ns;
681 	u32 ppbaud, pplow, odhpp, odbaud, odstop, i2cbaud, reg;
682 	int ret;
683 
684 	ret = pm_runtime_resume_and_get(master->dev);
685 	if (ret < 0) {
686 		dev_err(master->dev,
687 			"<%s> cannot resume i3c bus master, err: %d\n",
688 			__func__, ret);
689 		return ret;
690 	}
691 
692 	/* Timings derivation */
693 	fclk_rate = clk_get_rate(master->fclk);
694 	if (!fclk_rate) {
695 		ret = -EINVAL;
696 		goto rpm_out;
697 	}
698 
699 	fclk_period_ns = DIV_ROUND_UP(1000000000, fclk_rate);
700 	i2c_period_ns = DIV_ROUND_UP(1000000000, bus->scl_rate.i2c);
701 	i2c_scl_rate = bus->scl_rate.i2c;
702 	i3c_scl_rate = bus->scl_rate.i3c;
703 
704 	/*
705 	 * Using I3C Push-Pull mode, target is 12.5MHz/80ns period.
706 	 * Simplest configuration is using a 50% duty-cycle of 40ns.
707 	 */
708 	ppbaud = DIV_ROUND_UP(fclk_rate / 2, i3c_scl_rate) - 1;
709 	pplow = 0;
710 
711 	/*
712 	 * Using I3C Open-Drain mode, target is 4.17MHz/240ns with a
713 	 * duty-cycle tuned so that high levels are filetered out by
714 	 * the 50ns filter (target being 40ns).
715 	 */
716 	odhpp = 1;
717 	high_period_ns = (ppbaud + 1) * fclk_period_ns;
718 	odbaud = DIV_ROUND_UP(fclk_rate, SVC_I3C_QUICK_I2C_CLK * (1 + ppbaud)) - 2;
719 	od_low_period_ns = (odbaud + 1) * high_period_ns;
720 
721 	switch (bus->mode) {
722 	case I3C_BUS_MODE_PURE:
723 		i2cbaud = 0;
724 		odstop = 0;
725 		break;
726 	case I3C_BUS_MODE_MIXED_FAST:
727 		/*
728 		 * Using I2C Fm+ mode, target is 1MHz/1000ns, the difference
729 		 * between the high and low period does not really matter.
730 		 */
731 		i2cbaud = DIV_ROUND_UP(i2c_period_ns, od_low_period_ns) - 2;
732 		odstop = 1;
733 		break;
734 	case I3C_BUS_MODE_MIXED_LIMITED:
735 	case I3C_BUS_MODE_MIXED_SLOW:
736 		/* I3C PP + I3C OP + I2C OP both use i2c clk rate */
737 		if (ppbaud > SVC_I3C_PPBAUD_MAX) {
738 			ppbaud = SVC_I3C_PPBAUD_MAX;
739 			pplow =  DIV_ROUND_UP(fclk_rate, i3c_scl_rate) - (2 + 2 * ppbaud);
740 		}
741 
742 		high_period_ns = (ppbaud + 1) * fclk_period_ns;
743 		odhpp = 0;
744 		odbaud = DIV_ROUND_UP(fclk_rate, i2c_scl_rate * (2 + 2 * ppbaud)) - 1;
745 
746 		od_low_period_ns = (odbaud + 1) * high_period_ns;
747 		i2cbaud = DIV_ROUND_UP(i2c_period_ns, od_low_period_ns) - 2;
748 		odstop = 1;
749 		break;
750 	default:
751 		goto rpm_out;
752 	}
753 
754 	reg = SVC_I3C_MCONFIG_MASTER_EN |
755 	      SVC_I3C_MCONFIG_DISTO(0) |
756 	      SVC_I3C_MCONFIG_HKEEP(0) |
757 	      SVC_I3C_MCONFIG_ODSTOP(odstop) |
758 	      SVC_I3C_MCONFIG_PPBAUD(ppbaud) |
759 	      SVC_I3C_MCONFIG_PPLOW(pplow) |
760 	      SVC_I3C_MCONFIG_ODBAUD(odbaud) |
761 	      SVC_I3C_MCONFIG_ODHPP(odhpp) |
762 	      SVC_I3C_MCONFIG_SKEW(0) |
763 	      SVC_I3C_MCONFIG_I2CBAUD(i2cbaud);
764 	writel(reg, master->regs + SVC_I3C_MCONFIG);
765 
766 	master->mctrl_config = reg;
767 	/* Master core's registration */
768 	ret = i3c_master_get_free_addr(m, 0);
769 	if (ret < 0)
770 		goto rpm_out;
771 
772 	info.dyn_addr = ret;
773 
774 	writel(SVC_MDYNADDR_VALID | SVC_MDYNADDR_ADDR(info.dyn_addr),
775 	       master->regs + SVC_I3C_MDYNADDR);
776 
777 	ret = i3c_master_set_info(&master->base, &info);
778 	if (ret)
779 		goto rpm_out;
780 
781 rpm_out:
782 	pm_runtime_mark_last_busy(master->dev);
783 	pm_runtime_put_autosuspend(master->dev);
784 
785 	return ret;
786 }
787 
svc_i3c_master_bus_cleanup(struct i3c_master_controller * m)788 static void svc_i3c_master_bus_cleanup(struct i3c_master_controller *m)
789 {
790 	struct svc_i3c_master *master = to_svc_i3c_master(m);
791 	int ret;
792 
793 	ret = pm_runtime_resume_and_get(master->dev);
794 	if (ret < 0) {
795 		dev_err(master->dev, "<%s> Cannot get runtime PM.\n", __func__);
796 		return;
797 	}
798 
799 	svc_i3c_master_disable_interrupts(master);
800 
801 	/* Disable master */
802 	writel(0, master->regs + SVC_I3C_MCONFIG);
803 
804 	pm_runtime_mark_last_busy(master->dev);
805 	pm_runtime_put_autosuspend(master->dev);
806 }
807 
svc_i3c_master_reserve_slot(struct svc_i3c_master * master)808 static int svc_i3c_master_reserve_slot(struct svc_i3c_master *master)
809 {
810 	unsigned int slot;
811 
812 	if (!(master->free_slots & GENMASK(SVC_I3C_MAX_DEVS - 1, 0)))
813 		return -ENOSPC;
814 
815 	slot = ffs(master->free_slots) - 1;
816 
817 	master->free_slots &= ~BIT(slot);
818 
819 	return slot;
820 }
821 
svc_i3c_master_release_slot(struct svc_i3c_master * master,unsigned int slot)822 static void svc_i3c_master_release_slot(struct svc_i3c_master *master,
823 					unsigned int slot)
824 {
825 	master->free_slots |= BIT(slot);
826 }
827 
svc_i3c_master_attach_i3c_dev(struct i3c_dev_desc * dev)828 static int svc_i3c_master_attach_i3c_dev(struct i3c_dev_desc *dev)
829 {
830 	struct i3c_master_controller *m = i3c_dev_get_master(dev);
831 	struct svc_i3c_master *master = to_svc_i3c_master(m);
832 	struct svc_i3c_i2c_dev_data *data;
833 	int slot;
834 
835 	slot = svc_i3c_master_reserve_slot(master);
836 	if (slot < 0)
837 		return slot;
838 
839 	data = kzalloc(sizeof(*data), GFP_KERNEL);
840 	if (!data) {
841 		svc_i3c_master_release_slot(master, slot);
842 		return -ENOMEM;
843 	}
844 
845 	data->ibi = -1;
846 	data->index = slot;
847 	master->addrs[slot] = dev->info.dyn_addr ? dev->info.dyn_addr :
848 						   dev->info.static_addr;
849 	master->descs[slot] = dev;
850 
851 	i3c_dev_set_master_data(dev, data);
852 
853 	return 0;
854 }
855 
svc_i3c_master_reattach_i3c_dev(struct i3c_dev_desc * dev,u8 old_dyn_addr)856 static int svc_i3c_master_reattach_i3c_dev(struct i3c_dev_desc *dev,
857 					   u8 old_dyn_addr)
858 {
859 	struct i3c_master_controller *m = i3c_dev_get_master(dev);
860 	struct svc_i3c_master *master = to_svc_i3c_master(m);
861 	struct svc_i3c_i2c_dev_data *data = i3c_dev_get_master_data(dev);
862 
863 	master->addrs[data->index] = dev->info.dyn_addr ? dev->info.dyn_addr :
864 							  dev->info.static_addr;
865 
866 	return 0;
867 }
868 
svc_i3c_master_detach_i3c_dev(struct i3c_dev_desc * dev)869 static void svc_i3c_master_detach_i3c_dev(struct i3c_dev_desc *dev)
870 {
871 	struct svc_i3c_i2c_dev_data *data = i3c_dev_get_master_data(dev);
872 	struct i3c_master_controller *m = i3c_dev_get_master(dev);
873 	struct svc_i3c_master *master = to_svc_i3c_master(m);
874 
875 	master->addrs[data->index] = 0;
876 	svc_i3c_master_release_slot(master, data->index);
877 
878 	kfree(data);
879 }
880 
svc_i3c_master_attach_i2c_dev(struct i2c_dev_desc * dev)881 static int svc_i3c_master_attach_i2c_dev(struct i2c_dev_desc *dev)
882 {
883 	struct i3c_master_controller *m = i2c_dev_get_master(dev);
884 	struct svc_i3c_master *master = to_svc_i3c_master(m);
885 	struct svc_i3c_i2c_dev_data *data;
886 	int slot;
887 
888 	slot = svc_i3c_master_reserve_slot(master);
889 	if (slot < 0)
890 		return slot;
891 
892 	data = kzalloc(sizeof(*data), GFP_KERNEL);
893 	if (!data) {
894 		svc_i3c_master_release_slot(master, slot);
895 		return -ENOMEM;
896 	}
897 
898 	data->index = slot;
899 	master->addrs[slot] = dev->addr;
900 
901 	i2c_dev_set_master_data(dev, data);
902 
903 	return 0;
904 }
905 
svc_i3c_master_detach_i2c_dev(struct i2c_dev_desc * dev)906 static void svc_i3c_master_detach_i2c_dev(struct i2c_dev_desc *dev)
907 {
908 	struct svc_i3c_i2c_dev_data *data = i2c_dev_get_master_data(dev);
909 	struct i3c_master_controller *m = i2c_dev_get_master(dev);
910 	struct svc_i3c_master *master = to_svc_i3c_master(m);
911 
912 	svc_i3c_master_release_slot(master, data->index);
913 
914 	kfree(data);
915 }
916 
svc_i3c_master_readb(struct svc_i3c_master * master,u8 * dst,unsigned int len)917 static int svc_i3c_master_readb(struct svc_i3c_master *master, u8 *dst,
918 				unsigned int len)
919 {
920 	int ret, i;
921 	u32 reg;
922 
923 	for (i = 0; i < len; i++) {
924 		ret = readl_poll_timeout_atomic(master->regs + SVC_I3C_MSTATUS,
925 						reg,
926 						SVC_I3C_MSTATUS_RXPEND(reg),
927 						0, 1000);
928 		if (ret)
929 			return ret;
930 
931 		dst[i] = readl(master->regs + SVC_I3C_MRDATAB);
932 	}
933 
934 	return 0;
935 }
936 
svc_i3c_master_do_daa_locked(struct svc_i3c_master * master,u8 * addrs,unsigned int * count)937 static int svc_i3c_master_do_daa_locked(struct svc_i3c_master *master,
938 					u8 *addrs, unsigned int *count)
939 {
940 	u64 prov_id[SVC_I3C_MAX_DEVS] = {}, nacking_prov_id = 0;
941 	unsigned int dev_nb = 0, last_addr = 0, dyn_addr = 0;
942 	u32 reg;
943 	int ret, i;
944 
945 	svc_i3c_master_flush_fifo(master);
946 
947 	while (true) {
948 		/* clean SVC_I3C_MINT_IBIWON w1c bits */
949 		writel(SVC_I3C_MINT_IBIWON, master->regs + SVC_I3C_MSTATUS);
950 
951 		/* SVC_I3C_MCTRL_REQUEST_PROC_DAA have two mode, ENTER DAA or PROCESS DAA.
952 		 *
953 		 * ENTER DAA:
954 		 *   1 will issue START, 7E, ENTDAA, and then emits 7E/R to process first target.
955 		 *   2 Stops just before the new Dynamic Address (DA) is to be emitted.
956 		 *
957 		 * PROCESS DAA:
958 		 *   1 The DA is written using MWDATAB or ADDR bits 6:0.
959 		 *   2 ProcessDAA is requested again to write the new address, and then starts the
960 		 *     next (START, 7E, ENTDAA)  unless marked to STOP; an MSTATUS indicating NACK
961 		 *     means DA was not accepted (e.g. parity error). If PROCESSDAA is NACKed on the
962 		 *     7E/R, which means no more Slaves need a DA, then a COMPLETE will be signaled
963 		 *     (along with DONE), and a STOP issued automatically.
964 		 */
965 		writel(SVC_I3C_MCTRL_REQUEST_PROC_DAA |
966 		       SVC_I3C_MCTRL_TYPE_I3C |
967 		       SVC_I3C_MCTRL_IBIRESP_NACK |
968 		       SVC_I3C_MCTRL_DIR(SVC_I3C_MCTRL_DIR_WRITE),
969 		       master->regs + SVC_I3C_MCTRL);
970 
971 		/*
972 		 * Either one slave will send its ID, or the assignment process
973 		 * is done.
974 		 */
975 		ret = readl_poll_timeout_atomic(master->regs + SVC_I3C_MSTATUS,
976 						reg,
977 						SVC_I3C_MSTATUS_RXPEND(reg) |
978 						SVC_I3C_MSTATUS_MCTRLDONE(reg),
979 						1, 1000);
980 		if (ret)
981 			break;
982 
983 		if (SVC_I3C_MSTATUS_RXPEND(reg)) {
984 			u8 data[6];
985 
986 			/*
987 			 * One slave sends its ID to request for address assignment,
988 			 * prefilling the dynamic address can reduce SCL clock stalls
989 			 * and also fix the SVC_I3C_QUIRK_FIFO_EMPTY quirk.
990 			 *
991 			 * Ideally, prefilling before the processDAA command is better.
992 			 * However, it requires an additional check to write the dyn_addr
993 			 * at the right time because the driver needs to write the processDAA
994 			 * command twice for one assignment.
995 			 * Prefilling here is safe and efficient because the FIFO starts
996 			 * filling within a few hundred nanoseconds, which is significantly
997 			 * faster compared to the 64 SCL clock cycles.
998 			 */
999 			ret = i3c_master_get_free_addr(&master->base, last_addr + 1);
1000 			if (ret < 0)
1001 				break;
1002 
1003 			dyn_addr = ret;
1004 			writel(dyn_addr, master->regs + SVC_I3C_MWDATAB);
1005 
1006 			/*
1007 			 * We only care about the 48-bit provisioned ID yet to
1008 			 * be sure a device does not nack an address twice.
1009 			 * Otherwise, we would just need to flush the RX FIFO.
1010 			 */
1011 			ret = svc_i3c_master_readb(master, data, 6);
1012 			if (ret)
1013 				break;
1014 
1015 			for (i = 0; i < 6; i++)
1016 				prov_id[dev_nb] |= (u64)(data[i]) << (8 * (5 - i));
1017 
1018 			/* We do not care about the BCR and DCR yet */
1019 			ret = svc_i3c_master_readb(master, data, 2);
1020 			if (ret)
1021 				break;
1022 		} else if (SVC_I3C_MSTATUS_IBIWON(reg)) {
1023 			ret = svc_i3c_master_handle_ibi_won(master, reg);
1024 			if (ret)
1025 				break;
1026 			continue;
1027 		} else if (SVC_I3C_MSTATUS_MCTRLDONE(reg)) {
1028 			if (SVC_I3C_MSTATUS_STATE_IDLE(reg) &&
1029 			    SVC_I3C_MSTATUS_COMPLETE(reg)) {
1030 				/*
1031 				 * All devices received and acked they dynamic
1032 				 * address, this is the natural end of the DAA
1033 				 * procedure.
1034 				 *
1035 				 * Hardware will auto emit STOP at this case.
1036 				 */
1037 				*count = dev_nb;
1038 				return 0;
1039 
1040 			} else if (SVC_I3C_MSTATUS_NACKED(reg)) {
1041 				/* No I3C devices attached */
1042 				if (dev_nb == 0) {
1043 					/*
1044 					 * Hardware can't treat first NACK for ENTAA as normal
1045 					 * COMPLETE. So need manual emit STOP.
1046 					 */
1047 					ret = 0;
1048 					*count = 0;
1049 					break;
1050 				}
1051 
1052 				/*
1053 				 * A slave device nacked the address, this is
1054 				 * allowed only once, DAA will be stopped and
1055 				 * then resumed. The same device is supposed to
1056 				 * answer again immediately and shall ack the
1057 				 * address this time.
1058 				 */
1059 				if (prov_id[dev_nb] == nacking_prov_id) {
1060 					ret = -EIO;
1061 					break;
1062 				}
1063 
1064 				dev_nb--;
1065 				nacking_prov_id = prov_id[dev_nb];
1066 				svc_i3c_master_emit_stop(master);
1067 
1068 				continue;
1069 			} else {
1070 				break;
1071 			}
1072 		}
1073 
1074 		/* Wait for the slave to be ready to receive its address */
1075 		ret = readl_poll_timeout_atomic(master->regs + SVC_I3C_MSTATUS,
1076 						reg,
1077 						SVC_I3C_MSTATUS_MCTRLDONE(reg) &&
1078 						SVC_I3C_MSTATUS_STATE_DAA(reg) &&
1079 						SVC_I3C_MSTATUS_BETWEEN(reg),
1080 						0, 1000);
1081 		if (ret)
1082 			break;
1083 
1084 		addrs[dev_nb] = dyn_addr;
1085 		dev_dbg(master->dev, "DAA: device %d assigned to 0x%02x\n",
1086 			dev_nb, addrs[dev_nb]);
1087 		last_addr = addrs[dev_nb++];
1088 	}
1089 
1090 	/* Need manual issue STOP except for Complete condition */
1091 	svc_i3c_master_emit_stop(master);
1092 	svc_i3c_master_flush_fifo(master);
1093 
1094 	return ret;
1095 }
1096 
svc_i3c_update_ibirules(struct svc_i3c_master * master)1097 static int svc_i3c_update_ibirules(struct svc_i3c_master *master)
1098 {
1099 	struct i3c_dev_desc *dev;
1100 	u32 reg_mbyte = 0, reg_nobyte = SVC_I3C_IBIRULES_NOBYTE;
1101 	unsigned int mbyte_addr_ok = 0, mbyte_addr_ko = 0, nobyte_addr_ok = 0,
1102 		nobyte_addr_ko = 0;
1103 	bool list_mbyte = false, list_nobyte = false;
1104 
1105 	/* Create the IBIRULES register for both cases */
1106 	i3c_bus_for_each_i3cdev(&master->base.bus, dev) {
1107 		if (!(dev->info.bcr & I3C_BCR_IBI_REQ_CAP))
1108 			continue;
1109 
1110 		if (dev->info.bcr & I3C_BCR_IBI_PAYLOAD) {
1111 			reg_mbyte |= SVC_I3C_IBIRULES_ADDR(mbyte_addr_ok,
1112 							   dev->info.dyn_addr);
1113 
1114 			/* IBI rules cannot be applied to devices with MSb=1 */
1115 			if (dev->info.dyn_addr & BIT(7))
1116 				mbyte_addr_ko++;
1117 			else
1118 				mbyte_addr_ok++;
1119 		} else {
1120 			reg_nobyte |= SVC_I3C_IBIRULES_ADDR(nobyte_addr_ok,
1121 							    dev->info.dyn_addr);
1122 
1123 			/* IBI rules cannot be applied to devices with MSb=1 */
1124 			if (dev->info.dyn_addr & BIT(7))
1125 				nobyte_addr_ko++;
1126 			else
1127 				nobyte_addr_ok++;
1128 		}
1129 	}
1130 
1131 	/* Device list cannot be handled by hardware */
1132 	if (!mbyte_addr_ko && mbyte_addr_ok <= SVC_I3C_IBIRULES_ADDRS)
1133 		list_mbyte = true;
1134 
1135 	if (!nobyte_addr_ko && nobyte_addr_ok <= SVC_I3C_IBIRULES_ADDRS)
1136 		list_nobyte = true;
1137 
1138 	/* No list can be properly handled, return an error */
1139 	if (!list_mbyte && !list_nobyte)
1140 		return -ERANGE;
1141 
1142 	/* Pick the first list that can be handled by hardware, randomly */
1143 	if (list_mbyte)
1144 		writel(reg_mbyte, master->regs + SVC_I3C_IBIRULES);
1145 	else
1146 		writel(reg_nobyte, master->regs + SVC_I3C_IBIRULES);
1147 
1148 	return 0;
1149 }
1150 
svc_i3c_master_do_daa(struct i3c_master_controller * m)1151 static int svc_i3c_master_do_daa(struct i3c_master_controller *m)
1152 {
1153 	struct svc_i3c_master *master = to_svc_i3c_master(m);
1154 	u8 addrs[SVC_I3C_MAX_DEVS];
1155 	unsigned long flags;
1156 	unsigned int dev_nb;
1157 	int ret, i;
1158 
1159 	ret = pm_runtime_resume_and_get(master->dev);
1160 	if (ret < 0) {
1161 		dev_err(master->dev, "<%s> Cannot get runtime PM.\n", __func__);
1162 		return ret;
1163 	}
1164 
1165 	spin_lock_irqsave(&master->xferqueue.lock, flags);
1166 
1167 	if (svc_has_daa_corrupt(master))
1168 		writel(master->mctrl_config | SVC_I3C_MCONFIG_SKEW(1),
1169 		       master->regs + SVC_I3C_MCONFIG);
1170 
1171 	ret = svc_i3c_master_do_daa_locked(master, addrs, &dev_nb);
1172 
1173 	if (svc_has_daa_corrupt(master))
1174 		writel(master->mctrl_config, master->regs + SVC_I3C_MCONFIG);
1175 
1176 	spin_unlock_irqrestore(&master->xferqueue.lock, flags);
1177 
1178 	svc_i3c_master_clear_merrwarn(master);
1179 	if (ret)
1180 		goto rpm_out;
1181 
1182 	/*
1183 	 * Register all devices who participated to the core
1184 	 *
1185 	 * If two devices (A and B) are detected in DAA and address 0xa is assigned to
1186 	 * device A and 0xb to device B, a failure in i3c_master_add_i3c_dev_locked()
1187 	 * for device A (addr: 0xa) could prevent device B (addr: 0xb) from being
1188 	 * registered on the bus. The I3C stack might still consider 0xb a free
1189 	 * address. If a subsequent Hotjoin occurs, 0xb might be assigned to Device A,
1190 	 * causing both devices A and B to use the same address 0xb, violating the I3C
1191 	 * specification.
1192 	 *
1193 	 * The return value for i3c_master_add_i3c_dev_locked() should not be checked
1194 	 * because subsequent steps will scan the entire I3C bus, independent of
1195 	 * whether i3c_master_add_i3c_dev_locked() returns success.
1196 	 *
1197 	 * If device A registration fails, there is still a chance to register device
1198 	 * B. i3c_master_add_i3c_dev_locked() can reset DAA if a failure occurs while
1199 	 * retrieving device information.
1200 	 */
1201 	for (i = 0; i < dev_nb; i++)
1202 		i3c_master_add_i3c_dev_locked(m, addrs[i]);
1203 
1204 	/* Configure IBI auto-rules */
1205 	ret = svc_i3c_update_ibirules(master);
1206 	if (ret)
1207 		dev_err(master->dev, "Cannot handle such a list of devices");
1208 
1209 rpm_out:
1210 	pm_runtime_mark_last_busy(master->dev);
1211 	pm_runtime_put_autosuspend(master->dev);
1212 
1213 	return ret;
1214 }
1215 
svc_i3c_master_read(struct svc_i3c_master * master,u8 * in,unsigned int len)1216 static int svc_i3c_master_read(struct svc_i3c_master *master,
1217 			       u8 *in, unsigned int len)
1218 {
1219 	int offset = 0, i;
1220 	u32 mdctrl, mstatus;
1221 	bool completed = false;
1222 	unsigned int count;
1223 	unsigned long start = jiffies;
1224 
1225 	while (!completed) {
1226 		mstatus = readl(master->regs + SVC_I3C_MSTATUS);
1227 		if (SVC_I3C_MSTATUS_COMPLETE(mstatus) != 0)
1228 			completed = true;
1229 
1230 		if (time_after(jiffies, start + msecs_to_jiffies(1000))) {
1231 			dev_dbg(master->dev, "I3C read timeout\n");
1232 			return -ETIMEDOUT;
1233 		}
1234 
1235 		mdctrl = readl(master->regs + SVC_I3C_MDATACTRL);
1236 		count = SVC_I3C_MDATACTRL_RXCOUNT(mdctrl);
1237 		if (offset + count > len) {
1238 			dev_err(master->dev, "I3C receive length too long!\n");
1239 			return -EINVAL;
1240 		}
1241 		for (i = 0; i < count; i++)
1242 			in[offset + i] = readl(master->regs + SVC_I3C_MRDATAB);
1243 
1244 		offset += count;
1245 	}
1246 
1247 	return offset;
1248 }
1249 
svc_i3c_master_write(struct svc_i3c_master * master,const u8 * out,unsigned int len)1250 static int svc_i3c_master_write(struct svc_i3c_master *master,
1251 				const u8 *out, unsigned int len)
1252 {
1253 	int offset = 0, ret;
1254 	u32 mdctrl;
1255 
1256 	while (offset < len) {
1257 		ret = readl_poll_timeout(master->regs + SVC_I3C_MDATACTRL,
1258 					 mdctrl,
1259 					 !(mdctrl & SVC_I3C_MDATACTRL_TXFULL),
1260 					 0, 1000);
1261 		if (ret)
1262 			return ret;
1263 
1264 		/*
1265 		 * The last byte to be sent over the bus must either have the
1266 		 * "end" bit set or be written in MWDATABE.
1267 		 */
1268 		if (likely(offset < (len - 1)))
1269 			writel(out[offset++], master->regs + SVC_I3C_MWDATAB);
1270 		else
1271 			writel(out[offset++], master->regs + SVC_I3C_MWDATABE);
1272 	}
1273 
1274 	return 0;
1275 }
1276 
svc_i3c_master_xfer(struct svc_i3c_master * master,bool rnw,unsigned int xfer_type,u8 addr,u8 * in,const u8 * out,unsigned int xfer_len,unsigned int * actual_len,bool continued,bool repeat_start)1277 static int svc_i3c_master_xfer(struct svc_i3c_master *master,
1278 			       bool rnw, unsigned int xfer_type, u8 addr,
1279 			       u8 *in, const u8 *out, unsigned int xfer_len,
1280 			       unsigned int *actual_len, bool continued, bool repeat_start)
1281 {
1282 	int retry = repeat_start ? 1 : 2;
1283 	u32 reg;
1284 	int ret;
1285 
1286 	/* clean SVC_I3C_MINT_IBIWON w1c bits */
1287 	writel(SVC_I3C_MINT_IBIWON, master->regs + SVC_I3C_MSTATUS);
1288 
1289 
1290 	while (retry--) {
1291 		writel(SVC_I3C_MCTRL_REQUEST_START_ADDR |
1292 		       xfer_type |
1293 		       SVC_I3C_MCTRL_IBIRESP_NACK |
1294 		       SVC_I3C_MCTRL_DIR(rnw) |
1295 		       SVC_I3C_MCTRL_ADDR(addr) |
1296 		       SVC_I3C_MCTRL_RDTERM(*actual_len),
1297 		       master->regs + SVC_I3C_MCTRL);
1298 
1299 		/*
1300 		 * The entire transaction can consist of multiple write transfers.
1301 		 * Prefilling before EmitStartAddr causes the data to be emitted
1302 		 * immediately, becoming part of the previous transfer.
1303 		 * The only way to work around this hardware issue is to let the
1304 		 * FIFO start filling as soon as possible after EmitStartAddr.
1305 		 */
1306 		if (svc_has_quirk(master, SVC_I3C_QUIRK_FIFO_EMPTY) && !rnw && xfer_len) {
1307 			u32 end = xfer_len > SVC_I3C_FIFO_SIZE ? 0 : SVC_I3C_MWDATAB_END;
1308 			u32 len = min_t(u32, xfer_len, SVC_I3C_FIFO_SIZE);
1309 
1310 			writesb(master->regs + SVC_I3C_MWDATAB1, out, len - 1);
1311 			/* Mark END bit if this is the last byte */
1312 			writel(out[len - 1] | end, master->regs + SVC_I3C_MWDATAB);
1313 			xfer_len -= len;
1314 			out += len;
1315 		}
1316 
1317 		ret = readl_poll_timeout(master->regs + SVC_I3C_MSTATUS, reg,
1318 				 SVC_I3C_MSTATUS_MCTRLDONE(reg), 0, 1000);
1319 		if (ret)
1320 			goto emit_stop;
1321 
1322 		/*
1323 		 * According to I3C spec ver 1.1.1, 5.1.2.2.3 Consequence of Controller Starting a
1324 		 * Frame with I3C Target Address.
1325 		 *
1326 		 * The I3C Controller normally should start a Frame, the Address may be arbitrated,
1327 		 * and so the Controller shall monitor to see whether an In-Band Interrupt request,
1328 		 * a Controller Role Request (i.e., Secondary Controller requests to become the
1329 		 * Active Controller), or a Hot-Join Request has been made.
1330 		 *
1331 		 * If missed IBIWON check, the wrong data will be return. When IBIWON happen, issue
1332 		 * repeat start. Address arbitrate only happen at START, never happen at REPEAT
1333 		 * start.
1334 		 */
1335 		if (SVC_I3C_MSTATUS_IBIWON(reg)) {
1336 			ret = svc_i3c_master_handle_ibi_won(master, reg);
1337 			if (ret)
1338 				goto emit_stop;
1339 			continue;
1340 		}
1341 
1342 		if (readl(master->regs + SVC_I3C_MERRWARN) & SVC_I3C_MERRWARN_NACK) {
1343 			/*
1344 			 * According to I3C Spec 1.1.1, 11-Jun-2021, section: 5.1.2.2.3.
1345 			 * If the Controller chooses to start an I3C Message with an I3C Dynamic
1346 			 * Address, then special provisions shall be made because that same I3C
1347 			 * Target may be initiating an IBI or a Controller Role Request. So, one of
1348 			 * three things may happen: (skip 1, 2)
1349 			 *
1350 			 * 3. The Addresses match and the RnW bits also match, and so neither
1351 			 * Controller nor Target will ACK since both are expecting the other side to
1352 			 * provide ACK. As a result, each side might think it had "won" arbitration,
1353 			 * but neither side would continue, as each would subsequently see that the
1354 			 * other did not provide ACK.
1355 			 * ...
1356 			 * For either value of RnW: Due to the NACK, the Controller shall defer the
1357 			 * Private Write or Private Read, and should typically transmit the Target
1358 			 * Address again after a Repeated START (i.e., the next one or any one prior
1359 			 * to a STOP in the Frame). Since the Address Header following a Repeated
1360 			 * START is not arbitrated, the Controller will always win (see Section
1361 			 * 5.1.2.2.4).
1362 			 */
1363 			if (retry && addr != 0x7e) {
1364 				writel(SVC_I3C_MERRWARN_NACK, master->regs + SVC_I3C_MERRWARN);
1365 			} else {
1366 				ret = -ENXIO;
1367 				*actual_len = 0;
1368 				goto emit_stop;
1369 			}
1370 		} else {
1371 			break;
1372 		}
1373 	}
1374 
1375 	if (rnw)
1376 		ret = svc_i3c_master_read(master, in, xfer_len);
1377 	else
1378 		ret = svc_i3c_master_write(master, out, xfer_len);
1379 	if (ret < 0)
1380 		goto emit_stop;
1381 
1382 	if (rnw)
1383 		*actual_len = ret;
1384 
1385 	ret = readl_poll_timeout(master->regs + SVC_I3C_MSTATUS, reg,
1386 				 SVC_I3C_MSTATUS_COMPLETE(reg), 0, 1000);
1387 	if (ret)
1388 		goto emit_stop;
1389 
1390 	writel(SVC_I3C_MINT_COMPLETE, master->regs + SVC_I3C_MSTATUS);
1391 
1392 	if (!continued) {
1393 		svc_i3c_master_emit_stop(master);
1394 
1395 		/* Wait idle if stop is sent. */
1396 		readl_poll_timeout(master->regs + SVC_I3C_MSTATUS, reg,
1397 				   SVC_I3C_MSTATUS_STATE_IDLE(reg), 0, 1000);
1398 	}
1399 
1400 	return 0;
1401 
1402 emit_stop:
1403 	svc_i3c_master_emit_stop(master);
1404 	svc_i3c_master_clear_merrwarn(master);
1405 	svc_i3c_master_flush_fifo(master);
1406 
1407 	return ret;
1408 }
1409 
1410 static struct svc_i3c_xfer *
svc_i3c_master_alloc_xfer(struct svc_i3c_master * master,unsigned int ncmds)1411 svc_i3c_master_alloc_xfer(struct svc_i3c_master *master, unsigned int ncmds)
1412 {
1413 	struct svc_i3c_xfer *xfer;
1414 
1415 	xfer = kzalloc(struct_size(xfer, cmds, ncmds), GFP_KERNEL);
1416 	if (!xfer)
1417 		return NULL;
1418 
1419 	INIT_LIST_HEAD(&xfer->node);
1420 	xfer->ncmds = ncmds;
1421 	xfer->ret = -ETIMEDOUT;
1422 
1423 	return xfer;
1424 }
1425 
svc_i3c_master_free_xfer(struct svc_i3c_xfer * xfer)1426 static void svc_i3c_master_free_xfer(struct svc_i3c_xfer *xfer)
1427 {
1428 	kfree(xfer);
1429 }
1430 
svc_i3c_master_dequeue_xfer_locked(struct svc_i3c_master * master,struct svc_i3c_xfer * xfer)1431 static void svc_i3c_master_dequeue_xfer_locked(struct svc_i3c_master *master,
1432 					       struct svc_i3c_xfer *xfer)
1433 {
1434 	if (master->xferqueue.cur == xfer)
1435 		master->xferqueue.cur = NULL;
1436 	else
1437 		list_del_init(&xfer->node);
1438 }
1439 
svc_i3c_master_dequeue_xfer(struct svc_i3c_master * master,struct svc_i3c_xfer * xfer)1440 static void svc_i3c_master_dequeue_xfer(struct svc_i3c_master *master,
1441 					struct svc_i3c_xfer *xfer)
1442 {
1443 	unsigned long flags;
1444 
1445 	spin_lock_irqsave(&master->xferqueue.lock, flags);
1446 	svc_i3c_master_dequeue_xfer_locked(master, xfer);
1447 	spin_unlock_irqrestore(&master->xferqueue.lock, flags);
1448 }
1449 
svc_i3c_master_start_xfer_locked(struct svc_i3c_master * master)1450 static void svc_i3c_master_start_xfer_locked(struct svc_i3c_master *master)
1451 {
1452 	struct svc_i3c_xfer *xfer = master->xferqueue.cur;
1453 	int ret, i;
1454 
1455 	if (!xfer)
1456 		return;
1457 
1458 	svc_i3c_master_clear_merrwarn(master);
1459 	svc_i3c_master_flush_fifo(master);
1460 
1461 	for (i = 0; i < xfer->ncmds; i++) {
1462 		struct svc_i3c_cmd *cmd = &xfer->cmds[i];
1463 
1464 		ret = svc_i3c_master_xfer(master, cmd->rnw, xfer->type,
1465 					  cmd->addr, cmd->in, cmd->out,
1466 					  cmd->len, &cmd->actual_len,
1467 					  cmd->continued, i > 0);
1468 		/* cmd->xfer is NULL if I2C or CCC transfer */
1469 		if (cmd->xfer)
1470 			cmd->xfer->actual_len = cmd->actual_len;
1471 
1472 		if (ret)
1473 			break;
1474 	}
1475 
1476 	xfer->ret = ret;
1477 	complete(&xfer->comp);
1478 
1479 	if (ret < 0)
1480 		svc_i3c_master_dequeue_xfer_locked(master, xfer);
1481 
1482 	xfer = list_first_entry_or_null(&master->xferqueue.list,
1483 					struct svc_i3c_xfer,
1484 					node);
1485 	if (xfer)
1486 		list_del_init(&xfer->node);
1487 
1488 	master->xferqueue.cur = xfer;
1489 	svc_i3c_master_start_xfer_locked(master);
1490 }
1491 
svc_i3c_master_enqueue_xfer(struct svc_i3c_master * master,struct svc_i3c_xfer * xfer)1492 static void svc_i3c_master_enqueue_xfer(struct svc_i3c_master *master,
1493 					struct svc_i3c_xfer *xfer)
1494 {
1495 	unsigned long flags;
1496 	int ret;
1497 
1498 	ret = pm_runtime_resume_and_get(master->dev);
1499 	if (ret < 0) {
1500 		dev_err(master->dev, "<%s> Cannot get runtime PM.\n", __func__);
1501 		return;
1502 	}
1503 
1504 	init_completion(&xfer->comp);
1505 	spin_lock_irqsave(&master->xferqueue.lock, flags);
1506 	if (master->xferqueue.cur) {
1507 		list_add_tail(&xfer->node, &master->xferqueue.list);
1508 	} else {
1509 		master->xferqueue.cur = xfer;
1510 		svc_i3c_master_start_xfer_locked(master);
1511 	}
1512 	spin_unlock_irqrestore(&master->xferqueue.lock, flags);
1513 
1514 	pm_runtime_mark_last_busy(master->dev);
1515 	pm_runtime_put_autosuspend(master->dev);
1516 }
1517 
1518 static bool
svc_i3c_master_supports_ccc_cmd(struct i3c_master_controller * master,const struct i3c_ccc_cmd * cmd)1519 svc_i3c_master_supports_ccc_cmd(struct i3c_master_controller *master,
1520 				const struct i3c_ccc_cmd *cmd)
1521 {
1522 	/* No software support for CCC commands targeting more than one slave */
1523 	return (cmd->ndests == 1);
1524 }
1525 
svc_i3c_master_send_bdcast_ccc_cmd(struct svc_i3c_master * master,struct i3c_ccc_cmd * ccc)1526 static int svc_i3c_master_send_bdcast_ccc_cmd(struct svc_i3c_master *master,
1527 					      struct i3c_ccc_cmd *ccc)
1528 {
1529 	unsigned int xfer_len = ccc->dests[0].payload.len + 1;
1530 	struct svc_i3c_xfer *xfer;
1531 	struct svc_i3c_cmd *cmd;
1532 	u8 *buf;
1533 	int ret;
1534 
1535 	xfer = svc_i3c_master_alloc_xfer(master, 1);
1536 	if (!xfer)
1537 		return -ENOMEM;
1538 
1539 	buf = kmalloc(xfer_len, GFP_KERNEL);
1540 	if (!buf) {
1541 		svc_i3c_master_free_xfer(xfer);
1542 		return -ENOMEM;
1543 	}
1544 
1545 	buf[0] = ccc->id;
1546 	memcpy(&buf[1], ccc->dests[0].payload.data, ccc->dests[0].payload.len);
1547 
1548 	xfer->type = SVC_I3C_MCTRL_TYPE_I3C;
1549 
1550 	cmd = &xfer->cmds[0];
1551 	cmd->addr = ccc->dests[0].addr;
1552 	cmd->rnw = ccc->rnw;
1553 	cmd->in = NULL;
1554 	cmd->out = buf;
1555 	cmd->len = xfer_len;
1556 	cmd->actual_len = 0;
1557 	cmd->continued = false;
1558 
1559 	mutex_lock(&master->lock);
1560 	svc_i3c_master_enqueue_xfer(master, xfer);
1561 	if (!wait_for_completion_timeout(&xfer->comp, msecs_to_jiffies(1000)))
1562 		svc_i3c_master_dequeue_xfer(master, xfer);
1563 	mutex_unlock(&master->lock);
1564 
1565 	ret = xfer->ret;
1566 	kfree(buf);
1567 	svc_i3c_master_free_xfer(xfer);
1568 
1569 	return ret;
1570 }
1571 
svc_i3c_master_send_direct_ccc_cmd(struct svc_i3c_master * master,struct i3c_ccc_cmd * ccc)1572 static int svc_i3c_master_send_direct_ccc_cmd(struct svc_i3c_master *master,
1573 					      struct i3c_ccc_cmd *ccc)
1574 {
1575 	unsigned int xfer_len = ccc->dests[0].payload.len;
1576 	unsigned int actual_len = ccc->rnw ? xfer_len : 0;
1577 	struct svc_i3c_xfer *xfer;
1578 	struct svc_i3c_cmd *cmd;
1579 	int ret;
1580 
1581 	xfer = svc_i3c_master_alloc_xfer(master, 2);
1582 	if (!xfer)
1583 		return -ENOMEM;
1584 
1585 	xfer->type = SVC_I3C_MCTRL_TYPE_I3C;
1586 
1587 	/* Broadcasted message */
1588 	cmd = &xfer->cmds[0];
1589 	cmd->addr = I3C_BROADCAST_ADDR;
1590 	cmd->rnw = 0;
1591 	cmd->in = NULL;
1592 	cmd->out = &ccc->id;
1593 	cmd->len = 1;
1594 	cmd->actual_len = 0;
1595 	cmd->continued = true;
1596 
1597 	/* Directed message */
1598 	cmd = &xfer->cmds[1];
1599 	cmd->addr = ccc->dests[0].addr;
1600 	cmd->rnw = ccc->rnw;
1601 	cmd->in = ccc->rnw ? ccc->dests[0].payload.data : NULL;
1602 	cmd->out = ccc->rnw ? NULL : ccc->dests[0].payload.data;
1603 	cmd->len = xfer_len;
1604 	cmd->actual_len = actual_len;
1605 	cmd->continued = false;
1606 
1607 	mutex_lock(&master->lock);
1608 	svc_i3c_master_enqueue_xfer(master, xfer);
1609 	if (!wait_for_completion_timeout(&xfer->comp, msecs_to_jiffies(1000)))
1610 		svc_i3c_master_dequeue_xfer(master, xfer);
1611 	mutex_unlock(&master->lock);
1612 
1613 	if (cmd->actual_len != xfer_len)
1614 		ccc->dests[0].payload.len = cmd->actual_len;
1615 
1616 	ret = xfer->ret;
1617 	svc_i3c_master_free_xfer(xfer);
1618 
1619 	return ret;
1620 }
1621 
svc_i3c_master_send_ccc_cmd(struct i3c_master_controller * m,struct i3c_ccc_cmd * cmd)1622 static int svc_i3c_master_send_ccc_cmd(struct i3c_master_controller *m,
1623 				       struct i3c_ccc_cmd *cmd)
1624 {
1625 	struct svc_i3c_master *master = to_svc_i3c_master(m);
1626 	bool broadcast = cmd->id < 0x80;
1627 	int ret;
1628 
1629 	if (broadcast)
1630 		ret = svc_i3c_master_send_bdcast_ccc_cmd(master, cmd);
1631 	else
1632 		ret = svc_i3c_master_send_direct_ccc_cmd(master, cmd);
1633 
1634 	if (ret)
1635 		cmd->err = I3C_ERROR_M2;
1636 
1637 	return ret;
1638 }
1639 
svc_i3c_master_priv_xfers(struct i3c_dev_desc * dev,struct i3c_priv_xfer * xfers,int nxfers)1640 static int svc_i3c_master_priv_xfers(struct i3c_dev_desc *dev,
1641 				     struct i3c_priv_xfer *xfers,
1642 				     int nxfers)
1643 {
1644 	struct i3c_master_controller *m = i3c_dev_get_master(dev);
1645 	struct svc_i3c_master *master = to_svc_i3c_master(m);
1646 	struct svc_i3c_i2c_dev_data *data = i3c_dev_get_master_data(dev);
1647 	struct svc_i3c_xfer *xfer;
1648 	int ret, i;
1649 
1650 	xfer = svc_i3c_master_alloc_xfer(master, nxfers);
1651 	if (!xfer)
1652 		return -ENOMEM;
1653 
1654 	xfer->type = SVC_I3C_MCTRL_TYPE_I3C;
1655 
1656 	for (i = 0; i < nxfers; i++) {
1657 		struct svc_i3c_cmd *cmd = &xfer->cmds[i];
1658 
1659 		cmd->xfer = &xfers[i];
1660 		cmd->addr = master->addrs[data->index];
1661 		cmd->rnw = xfers[i].rnw;
1662 		cmd->in = xfers[i].rnw ? xfers[i].data.in : NULL;
1663 		cmd->out = xfers[i].rnw ? NULL : xfers[i].data.out;
1664 		cmd->len = xfers[i].len;
1665 		cmd->actual_len = xfers[i].rnw ? xfers[i].len : 0;
1666 		cmd->continued = (i + 1) < nxfers;
1667 	}
1668 
1669 	mutex_lock(&master->lock);
1670 	svc_i3c_master_enqueue_xfer(master, xfer);
1671 	if (!wait_for_completion_timeout(&xfer->comp, msecs_to_jiffies(1000)))
1672 		svc_i3c_master_dequeue_xfer(master, xfer);
1673 	mutex_unlock(&master->lock);
1674 
1675 	ret = xfer->ret;
1676 	svc_i3c_master_free_xfer(xfer);
1677 
1678 	return ret;
1679 }
1680 
svc_i3c_master_i2c_xfers(struct i2c_dev_desc * dev,struct i2c_msg * xfers,int nxfers)1681 static int svc_i3c_master_i2c_xfers(struct i2c_dev_desc *dev,
1682 				    struct i2c_msg *xfers,
1683 				    int nxfers)
1684 {
1685 	struct i3c_master_controller *m = i2c_dev_get_master(dev);
1686 	struct svc_i3c_master *master = to_svc_i3c_master(m);
1687 	struct svc_i3c_i2c_dev_data *data = i2c_dev_get_master_data(dev);
1688 	struct svc_i3c_xfer *xfer;
1689 	int ret, i;
1690 
1691 	xfer = svc_i3c_master_alloc_xfer(master, nxfers);
1692 	if (!xfer)
1693 		return -ENOMEM;
1694 
1695 	xfer->type = SVC_I3C_MCTRL_TYPE_I2C;
1696 
1697 	for (i = 0; i < nxfers; i++) {
1698 		struct svc_i3c_cmd *cmd = &xfer->cmds[i];
1699 
1700 		cmd->addr = master->addrs[data->index];
1701 		cmd->rnw = xfers[i].flags & I2C_M_RD;
1702 		cmd->in = cmd->rnw ? xfers[i].buf : NULL;
1703 		cmd->out = cmd->rnw ? NULL : xfers[i].buf;
1704 		cmd->len = xfers[i].len;
1705 		cmd->actual_len = cmd->rnw ? xfers[i].len : 0;
1706 		cmd->continued = (i + 1 < nxfers);
1707 	}
1708 
1709 	mutex_lock(&master->lock);
1710 	svc_i3c_master_enqueue_xfer(master, xfer);
1711 	if (!wait_for_completion_timeout(&xfer->comp, msecs_to_jiffies(1000)))
1712 		svc_i3c_master_dequeue_xfer(master, xfer);
1713 	mutex_unlock(&master->lock);
1714 
1715 	ret = xfer->ret;
1716 	svc_i3c_master_free_xfer(xfer);
1717 
1718 	return ret;
1719 }
1720 
svc_i3c_master_request_ibi(struct i3c_dev_desc * dev,const struct i3c_ibi_setup * req)1721 static int svc_i3c_master_request_ibi(struct i3c_dev_desc *dev,
1722 				      const struct i3c_ibi_setup *req)
1723 {
1724 	struct i3c_master_controller *m = i3c_dev_get_master(dev);
1725 	struct svc_i3c_master *master = to_svc_i3c_master(m);
1726 	struct svc_i3c_i2c_dev_data *data = i3c_dev_get_master_data(dev);
1727 	unsigned long flags;
1728 	unsigned int i;
1729 
1730 	if (dev->ibi->max_payload_len > SVC_I3C_FIFO_SIZE) {
1731 		dev_err(master->dev, "IBI max payload %d should be < %d\n",
1732 			dev->ibi->max_payload_len, SVC_I3C_FIFO_SIZE);
1733 		return -ERANGE;
1734 	}
1735 
1736 	data->ibi_pool = i3c_generic_ibi_alloc_pool(dev, req);
1737 	if (IS_ERR(data->ibi_pool))
1738 		return PTR_ERR(data->ibi_pool);
1739 
1740 	spin_lock_irqsave(&master->ibi.lock, flags);
1741 	for (i = 0; i < master->ibi.num_slots; i++) {
1742 		if (!master->ibi.slots[i]) {
1743 			data->ibi = i;
1744 			master->ibi.slots[i] = dev;
1745 			break;
1746 		}
1747 	}
1748 	spin_unlock_irqrestore(&master->ibi.lock, flags);
1749 
1750 	if (i < master->ibi.num_slots)
1751 		return 0;
1752 
1753 	i3c_generic_ibi_free_pool(data->ibi_pool);
1754 	data->ibi_pool = NULL;
1755 
1756 	return -ENOSPC;
1757 }
1758 
svc_i3c_master_free_ibi(struct i3c_dev_desc * dev)1759 static void svc_i3c_master_free_ibi(struct i3c_dev_desc *dev)
1760 {
1761 	struct i3c_master_controller *m = i3c_dev_get_master(dev);
1762 	struct svc_i3c_master *master = to_svc_i3c_master(m);
1763 	struct svc_i3c_i2c_dev_data *data = i3c_dev_get_master_data(dev);
1764 	unsigned long flags;
1765 
1766 	spin_lock_irqsave(&master->ibi.lock, flags);
1767 	master->ibi.slots[data->ibi] = NULL;
1768 	data->ibi = -1;
1769 	spin_unlock_irqrestore(&master->ibi.lock, flags);
1770 
1771 	i3c_generic_ibi_free_pool(data->ibi_pool);
1772 }
1773 
svc_i3c_master_enable_ibi(struct i3c_dev_desc * dev)1774 static int svc_i3c_master_enable_ibi(struct i3c_dev_desc *dev)
1775 {
1776 	struct i3c_master_controller *m = i3c_dev_get_master(dev);
1777 	struct svc_i3c_master *master = to_svc_i3c_master(m);
1778 	int ret;
1779 
1780 	ret = pm_runtime_resume_and_get(master->dev);
1781 	if (ret < 0) {
1782 		dev_err(master->dev, "<%s> Cannot get runtime PM.\n", __func__);
1783 		return ret;
1784 	}
1785 
1786 	master->enabled_events++;
1787 	svc_i3c_master_enable_interrupts(master, SVC_I3C_MINT_SLVSTART);
1788 
1789 	return i3c_master_enec_locked(m, dev->info.dyn_addr, I3C_CCC_EVENT_SIR);
1790 }
1791 
svc_i3c_master_disable_ibi(struct i3c_dev_desc * dev)1792 static int svc_i3c_master_disable_ibi(struct i3c_dev_desc *dev)
1793 {
1794 	struct i3c_master_controller *m = i3c_dev_get_master(dev);
1795 	struct svc_i3c_master *master = to_svc_i3c_master(m);
1796 	int ret;
1797 
1798 	master->enabled_events--;
1799 	if (!master->enabled_events)
1800 		svc_i3c_master_disable_interrupts(master);
1801 
1802 	ret = i3c_master_disec_locked(m, dev->info.dyn_addr, I3C_CCC_EVENT_SIR);
1803 
1804 	pm_runtime_mark_last_busy(master->dev);
1805 	pm_runtime_put_autosuspend(master->dev);
1806 
1807 	return ret;
1808 }
1809 
svc_i3c_master_enable_hotjoin(struct i3c_master_controller * m)1810 static int svc_i3c_master_enable_hotjoin(struct i3c_master_controller *m)
1811 {
1812 	struct svc_i3c_master *master = to_svc_i3c_master(m);
1813 	int ret;
1814 
1815 	ret = pm_runtime_resume_and_get(master->dev);
1816 	if (ret < 0) {
1817 		dev_err(master->dev, "<%s> Cannot get runtime PM.\n", __func__);
1818 		return ret;
1819 	}
1820 
1821 	master->enabled_events |= SVC_I3C_EVENT_HOTJOIN;
1822 
1823 	svc_i3c_master_enable_interrupts(master, SVC_I3C_MINT_SLVSTART);
1824 
1825 	return 0;
1826 }
1827 
svc_i3c_master_disable_hotjoin(struct i3c_master_controller * m)1828 static int svc_i3c_master_disable_hotjoin(struct i3c_master_controller *m)
1829 {
1830 	struct svc_i3c_master *master = to_svc_i3c_master(m);
1831 
1832 	master->enabled_events &= ~SVC_I3C_EVENT_HOTJOIN;
1833 
1834 	if (!master->enabled_events)
1835 		svc_i3c_master_disable_interrupts(master);
1836 
1837 	pm_runtime_mark_last_busy(master->dev);
1838 	pm_runtime_put_autosuspend(master->dev);
1839 
1840 	return 0;
1841 }
1842 
svc_i3c_master_recycle_ibi_slot(struct i3c_dev_desc * dev,struct i3c_ibi_slot * slot)1843 static void svc_i3c_master_recycle_ibi_slot(struct i3c_dev_desc *dev,
1844 					    struct i3c_ibi_slot *slot)
1845 {
1846 	struct svc_i3c_i2c_dev_data *data = i3c_dev_get_master_data(dev);
1847 
1848 	i3c_generic_ibi_recycle_slot(data->ibi_pool, slot);
1849 }
1850 
1851 static const struct i3c_master_controller_ops svc_i3c_master_ops = {
1852 	.bus_init = svc_i3c_master_bus_init,
1853 	.bus_cleanup = svc_i3c_master_bus_cleanup,
1854 	.attach_i3c_dev = svc_i3c_master_attach_i3c_dev,
1855 	.detach_i3c_dev = svc_i3c_master_detach_i3c_dev,
1856 	.reattach_i3c_dev = svc_i3c_master_reattach_i3c_dev,
1857 	.attach_i2c_dev = svc_i3c_master_attach_i2c_dev,
1858 	.detach_i2c_dev = svc_i3c_master_detach_i2c_dev,
1859 	.do_daa = svc_i3c_master_do_daa,
1860 	.supports_ccc_cmd = svc_i3c_master_supports_ccc_cmd,
1861 	.send_ccc_cmd = svc_i3c_master_send_ccc_cmd,
1862 	.priv_xfers = svc_i3c_master_priv_xfers,
1863 	.i2c_xfers = svc_i3c_master_i2c_xfers,
1864 	.request_ibi = svc_i3c_master_request_ibi,
1865 	.free_ibi = svc_i3c_master_free_ibi,
1866 	.recycle_ibi_slot = svc_i3c_master_recycle_ibi_slot,
1867 	.enable_ibi = svc_i3c_master_enable_ibi,
1868 	.disable_ibi = svc_i3c_master_disable_ibi,
1869 	.enable_hotjoin = svc_i3c_master_enable_hotjoin,
1870 	.disable_hotjoin = svc_i3c_master_disable_hotjoin,
1871 	.set_speed = svc_i3c_master_set_speed,
1872 };
1873 
svc_i3c_master_probe(struct platform_device * pdev)1874 static int svc_i3c_master_probe(struct platform_device *pdev)
1875 {
1876 	struct device *dev = &pdev->dev;
1877 	struct svc_i3c_master *master;
1878 	int ret, i;
1879 
1880 	master = devm_kzalloc(dev, sizeof(*master), GFP_KERNEL);
1881 	if (!master)
1882 		return -ENOMEM;
1883 
1884 	master->drvdata = of_device_get_match_data(dev);
1885 	if (!master->drvdata)
1886 		return -EINVAL;
1887 
1888 	master->regs = devm_platform_ioremap_resource(pdev, 0);
1889 	if (IS_ERR(master->regs))
1890 		return PTR_ERR(master->regs);
1891 
1892 	master->num_clks = devm_clk_bulk_get_all(dev, &master->clks);
1893 	if (master->num_clks < 0)
1894 		return dev_err_probe(dev, -EINVAL, "can't get I3C clocks\n");
1895 
1896 	for (i = 0; i < master->num_clks; i++) {
1897 		if (!strcmp(master->clks[i].id, "fast_clk"))
1898 			break;
1899 	}
1900 
1901 	if (i == master->num_clks)
1902 		return dev_err_probe(dev, -EINVAL,
1903 				     "can't get I3C peripheral clock\n");
1904 
1905 	master->fclk = master->clks[i].clk;
1906 	if (IS_ERR(master->fclk))
1907 		return PTR_ERR(master->fclk);
1908 
1909 	master->irq = platform_get_irq(pdev, 0);
1910 	if (master->irq < 0)
1911 		return master->irq;
1912 
1913 	master->dev = dev;
1914 	ret = clk_bulk_prepare_enable(master->num_clks, master->clks);
1915 	if (ret)
1916 		return dev_err_probe(dev, ret, "can't enable I3C clocks\n");
1917 
1918 	INIT_WORK(&master->hj_work, svc_i3c_master_hj_work);
1919 	mutex_init(&master->lock);
1920 
1921 	ret = devm_request_irq(dev, master->irq, svc_i3c_master_irq_handler,
1922 			       IRQF_NO_SUSPEND, "svc-i3c-irq", master);
1923 	if (ret)
1924 		goto err_disable_clks;
1925 
1926 	master->free_slots = GENMASK(SVC_I3C_MAX_DEVS - 1, 0);
1927 
1928 	spin_lock_init(&master->xferqueue.lock);
1929 	INIT_LIST_HEAD(&master->xferqueue.list);
1930 
1931 	spin_lock_init(&master->ibi.lock);
1932 	master->ibi.num_slots = SVC_I3C_MAX_DEVS;
1933 	master->ibi.slots = devm_kcalloc(&pdev->dev, master->ibi.num_slots,
1934 					 sizeof(*master->ibi.slots),
1935 					 GFP_KERNEL);
1936 	if (!master->ibi.slots) {
1937 		ret = -ENOMEM;
1938 		goto err_disable_clks;
1939 	}
1940 
1941 	platform_set_drvdata(pdev, master);
1942 
1943 	pm_runtime_set_autosuspend_delay(&pdev->dev, SVC_I3C_PM_TIMEOUT_MS);
1944 	pm_runtime_use_autosuspend(&pdev->dev);
1945 	pm_runtime_get_noresume(&pdev->dev);
1946 	pm_runtime_set_active(&pdev->dev);
1947 	pm_runtime_enable(&pdev->dev);
1948 
1949 	svc_i3c_master_reset(master);
1950 
1951 	/* Register the master */
1952 	ret = i3c_master_register(&master->base, &pdev->dev,
1953 				  &svc_i3c_master_ops, false);
1954 	if (ret)
1955 		goto rpm_disable;
1956 
1957 	pm_runtime_mark_last_busy(&pdev->dev);
1958 	pm_runtime_put_autosuspend(&pdev->dev);
1959 
1960 	return 0;
1961 
1962 rpm_disable:
1963 	pm_runtime_dont_use_autosuspend(&pdev->dev);
1964 	pm_runtime_put_noidle(&pdev->dev);
1965 	pm_runtime_disable(&pdev->dev);
1966 	pm_runtime_set_suspended(&pdev->dev);
1967 
1968 err_disable_clks:
1969 	clk_bulk_disable_unprepare(master->num_clks, master->clks);
1970 
1971 	return ret;
1972 }
1973 
svc_i3c_master_remove(struct platform_device * pdev)1974 static void svc_i3c_master_remove(struct platform_device *pdev)
1975 {
1976 	struct svc_i3c_master *master = platform_get_drvdata(pdev);
1977 
1978 	cancel_work_sync(&master->hj_work);
1979 	i3c_master_unregister(&master->base);
1980 
1981 	pm_runtime_dont_use_autosuspend(&pdev->dev);
1982 	pm_runtime_disable(&pdev->dev);
1983 }
1984 
svc_i3c_save_regs(struct svc_i3c_master * master)1985 static void svc_i3c_save_regs(struct svc_i3c_master *master)
1986 {
1987 	master->saved_regs.mconfig = readl(master->regs + SVC_I3C_MCONFIG);
1988 	master->saved_regs.mdynaddr = readl(master->regs + SVC_I3C_MDYNADDR);
1989 }
1990 
svc_i3c_restore_regs(struct svc_i3c_master * master)1991 static void svc_i3c_restore_regs(struct svc_i3c_master *master)
1992 {
1993 	if (readl(master->regs + SVC_I3C_MDYNADDR) !=
1994 	    master->saved_regs.mdynaddr) {
1995 		writel(master->saved_regs.mconfig,
1996 		       master->regs + SVC_I3C_MCONFIG);
1997 		writel(master->saved_regs.mdynaddr,
1998 		       master->regs + SVC_I3C_MDYNADDR);
1999 	}
2000 }
2001 
svc_i3c_runtime_suspend(struct device * dev)2002 static int __maybe_unused svc_i3c_runtime_suspend(struct device *dev)
2003 {
2004 	struct svc_i3c_master *master = dev_get_drvdata(dev);
2005 
2006 	svc_i3c_save_regs(master);
2007 	clk_bulk_disable_unprepare(master->num_clks, master->clks);
2008 	pinctrl_pm_select_sleep_state(dev);
2009 
2010 	return 0;
2011 }
2012 
svc_i3c_runtime_resume(struct device * dev)2013 static int __maybe_unused svc_i3c_runtime_resume(struct device *dev)
2014 {
2015 	struct svc_i3c_master *master = dev_get_drvdata(dev);
2016 	int ret;
2017 
2018 	pinctrl_pm_select_default_state(dev);
2019 	ret = clk_bulk_prepare_enable(master->num_clks, master->clks);
2020 	if (ret)
2021 		return ret;
2022 
2023 	svc_i3c_restore_regs(master);
2024 
2025 	return 0;
2026 }
2027 
2028 static const struct dev_pm_ops svc_i3c_pm_ops = {
2029 	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
2030 				      pm_runtime_force_resume)
2031 	SET_RUNTIME_PM_OPS(svc_i3c_runtime_suspend,
2032 			   svc_i3c_runtime_resume, NULL)
2033 };
2034 
2035 static const struct svc_i3c_drvdata npcm845_drvdata = {
2036 	.quirks = SVC_I3C_QUIRK_FIFO_EMPTY |
2037 		SVC_I3C_QUIRK_FALSE_SLVSTART |
2038 		SVC_I3C_QUIRK_DAA_CORRUPT,
2039 };
2040 
2041 static const struct svc_i3c_drvdata svc_default_drvdata = {};
2042 
2043 static const struct of_device_id svc_i3c_master_of_match_tbl[] = {
2044 	{ .compatible = "nuvoton,npcm845-i3c", .data = &npcm845_drvdata },
2045 	{ .compatible = "silvaco,i3c-master-v1", .data = &svc_default_drvdata },
2046 	{ /* sentinel */ },
2047 };
2048 MODULE_DEVICE_TABLE(of, svc_i3c_master_of_match_tbl);
2049 
2050 static struct platform_driver svc_i3c_master = {
2051 	.probe = svc_i3c_master_probe,
2052 	.remove = svc_i3c_master_remove,
2053 	.driver = {
2054 		.name = "silvaco-i3c-master",
2055 		.of_match_table = svc_i3c_master_of_match_tbl,
2056 		.pm = &svc_i3c_pm_ops,
2057 	},
2058 };
2059 module_platform_driver(svc_i3c_master);
2060 
2061 MODULE_AUTHOR("Conor Culhane <conor.culhane@silvaco.com>");
2062 MODULE_AUTHOR("Miquel Raynal <miquel.raynal@bootlin.com>");
2063 MODULE_DESCRIPTION("Silvaco dual-role I3C master driver");
2064 MODULE_LICENSE("GPL v2");
2065