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/platform_device.h>
21 
22 /* Master Mode Registers */
23 #define SVC_I3C_MCONFIG      0x000
24 #define   SVC_I3C_MCONFIG_MASTER_EN BIT(0)
25 #define   SVC_I3C_MCONFIG_DISTO(x) FIELD_PREP(BIT(3), (x))
26 #define   SVC_I3C_MCONFIG_HKEEP(x) FIELD_PREP(GENMASK(5, 4), (x))
27 #define   SVC_I3C_MCONFIG_ODSTOP(x) FIELD_PREP(BIT(6), (x))
28 #define   SVC_I3C_MCONFIG_PPBAUD(x) FIELD_PREP(GENMASK(11, 8), (x))
29 #define   SVC_I3C_MCONFIG_PPLOW(x) FIELD_PREP(GENMASK(15, 12), (x))
30 #define   SVC_I3C_MCONFIG_ODBAUD(x) FIELD_PREP(GENMASK(23, 16), (x))
31 #define   SVC_I3C_MCONFIG_ODHPP(x) FIELD_PREP(BIT(24), (x))
32 #define   SVC_I3C_MCONFIG_SKEW(x) FIELD_PREP(GENMASK(27, 25), (x))
33 #define   SVC_I3C_MCONFIG_I2CBAUD(x) FIELD_PREP(GENMASK(31, 28), (x))
34 
35 #define SVC_I3C_MCTRL        0x084
36 #define   SVC_I3C_MCTRL_REQUEST_MASK GENMASK(2, 0)
37 #define   SVC_I3C_MCTRL_REQUEST_NONE 0
38 #define   SVC_I3C_MCTRL_REQUEST_START_ADDR 1
39 #define   SVC_I3C_MCTRL_REQUEST_STOP 2
40 #define   SVC_I3C_MCTRL_REQUEST_IBI_ACKNACK 3
41 #define   SVC_I3C_MCTRL_REQUEST_PROC_DAA 4
42 #define   SVC_I3C_MCTRL_REQUEST_AUTO_IBI 7
43 #define   SVC_I3C_MCTRL_TYPE_I3C 0
44 #define   SVC_I3C_MCTRL_TYPE_I2C BIT(4)
45 #define   SVC_I3C_MCTRL_IBIRESP_AUTO 0
46 #define   SVC_I3C_MCTRL_IBIRESP_ACK_WITHOUT_BYTE 0
47 #define   SVC_I3C_MCTRL_IBIRESP_ACK_WITH_BYTE BIT(7)
48 #define   SVC_I3C_MCTRL_IBIRESP_NACK BIT(6)
49 #define   SVC_I3C_MCTRL_IBIRESP_MANUAL GENMASK(7, 6)
50 #define   SVC_I3C_MCTRL_DIR(x) FIELD_PREP(BIT(8), (x))
51 #define   SVC_I3C_MCTRL_DIR_WRITE 0
52 #define   SVC_I3C_MCTRL_DIR_READ 1
53 #define   SVC_I3C_MCTRL_ADDR(x) FIELD_PREP(GENMASK(15, 9), (x))
54 #define   SVC_I3C_MCTRL_RDTERM(x) FIELD_PREP(GENMASK(23, 16), (x))
55 
56 #define SVC_I3C_MSTATUS      0x088
57 #define   SVC_I3C_MSTATUS_STATE(x) FIELD_GET(GENMASK(2, 0), (x))
58 #define   SVC_I3C_MSTATUS_STATE_DAA(x) (SVC_I3C_MSTATUS_STATE(x) == 5)
59 #define   SVC_I3C_MSTATUS_STATE_IDLE(x) (SVC_I3C_MSTATUS_STATE(x) == 0)
60 #define   SVC_I3C_MSTATUS_BETWEEN(x) FIELD_GET(BIT(4), (x))
61 #define   SVC_I3C_MSTATUS_NACKED(x) FIELD_GET(BIT(5), (x))
62 #define   SVC_I3C_MSTATUS_IBITYPE(x) FIELD_GET(GENMASK(7, 6), (x))
63 #define   SVC_I3C_MSTATUS_IBITYPE_IBI 1
64 #define   SVC_I3C_MSTATUS_IBITYPE_MASTER_REQUEST 2
65 #define   SVC_I3C_MSTATUS_IBITYPE_HOT_JOIN 3
66 #define   SVC_I3C_MINT_SLVSTART BIT(8)
67 #define   SVC_I3C_MINT_MCTRLDONE BIT(9)
68 #define   SVC_I3C_MINT_COMPLETE BIT(10)
69 #define   SVC_I3C_MINT_RXPEND BIT(11)
70 #define   SVC_I3C_MINT_TXNOTFULL BIT(12)
71 #define   SVC_I3C_MINT_IBIWON BIT(13)
72 #define   SVC_I3C_MINT_ERRWARN BIT(15)
73 #define   SVC_I3C_MSTATUS_SLVSTART(x) FIELD_GET(SVC_I3C_MINT_SLVSTART, (x))
74 #define   SVC_I3C_MSTATUS_MCTRLDONE(x) FIELD_GET(SVC_I3C_MINT_MCTRLDONE, (x))
75 #define   SVC_I3C_MSTATUS_COMPLETE(x) FIELD_GET(SVC_I3C_MINT_COMPLETE, (x))
76 #define   SVC_I3C_MSTATUS_RXPEND(x) FIELD_GET(SVC_I3C_MINT_RXPEND, (x))
77 #define   SVC_I3C_MSTATUS_TXNOTFULL(x) FIELD_GET(SVC_I3C_MINT_TXNOTFULL, (x))
78 #define   SVC_I3C_MSTATUS_IBIWON(x) FIELD_GET(SVC_I3C_MINT_IBIWON, (x))
79 #define   SVC_I3C_MSTATUS_ERRWARN(x) FIELD_GET(SVC_I3C_MINT_ERRWARN, (x))
80 #define   SVC_I3C_MSTATUS_IBIADDR(x) FIELD_GET(GENMASK(30, 24), (x))
81 
82 #define SVC_I3C_IBIRULES     0x08C
83 #define   SVC_I3C_IBIRULES_ADDR(slot, addr) FIELD_PREP(GENMASK(29, 0), \
84 						       ((addr) & 0x3F) << ((slot) * 6))
85 #define   SVC_I3C_IBIRULES_ADDRS 5
86 #define   SVC_I3C_IBIRULES_MSB0 BIT(30)
87 #define   SVC_I3C_IBIRULES_NOBYTE BIT(31)
88 #define   SVC_I3C_IBIRULES_MANDBYTE 0
89 #define SVC_I3C_MINTSET      0x090
90 #define SVC_I3C_MINTCLR      0x094
91 #define SVC_I3C_MINTMASKED   0x098
92 #define SVC_I3C_MERRWARN     0x09C
93 #define SVC_I3C_MDMACTRL     0x0A0
94 #define SVC_I3C_MDATACTRL    0x0AC
95 #define   SVC_I3C_MDATACTRL_FLUSHTB BIT(0)
96 #define   SVC_I3C_MDATACTRL_FLUSHRB BIT(1)
97 #define   SVC_I3C_MDATACTRL_UNLOCK_TRIG BIT(3)
98 #define   SVC_I3C_MDATACTRL_TXTRIG_FIFO_NOT_FULL GENMASK(5, 4)
99 #define   SVC_I3C_MDATACTRL_RXTRIG_FIFO_NOT_EMPTY 0
100 #define   SVC_I3C_MDATACTRL_RXCOUNT(x) FIELD_GET(GENMASK(28, 24), (x))
101 #define   SVC_I3C_MDATACTRL_TXFULL BIT(30)
102 #define   SVC_I3C_MDATACTRL_RXEMPTY BIT(31)
103 
104 #define SVC_I3C_MWDATAB      0x0B0
105 #define   SVC_I3C_MWDATAB_END BIT(8)
106 
107 #define SVC_I3C_MWDATABE     0x0B4
108 #define SVC_I3C_MWDATAH      0x0B8
109 #define SVC_I3C_MWDATAHE     0x0BC
110 #define SVC_I3C_MRDATAB      0x0C0
111 #define SVC_I3C_MRDATAH      0x0C8
112 #define SVC_I3C_MWMSG_SDR    0x0D0
113 #define SVC_I3C_MRMSG_SDR    0x0D4
114 #define SVC_I3C_MWMSG_DDR    0x0D8
115 #define SVC_I3C_MRMSG_DDR    0x0DC
116 
117 #define SVC_I3C_MDYNADDR     0x0E4
118 #define   SVC_MDYNADDR_VALID BIT(0)
119 #define   SVC_MDYNADDR_ADDR(x) FIELD_PREP(GENMASK(7, 1), (x))
120 
121 #define SVC_I3C_MAX_DEVS 32
122 
123 /* This parameter depends on the implementation and may be tuned */
124 #define SVC_I3C_FIFO_SIZE 16
125 
126 struct svc_i3c_cmd {
127 	u8 addr;
128 	bool rnw;
129 	u8 *in;
130 	const void *out;
131 	unsigned int len;
132 	unsigned int read_len;
133 	bool continued;
134 };
135 
136 struct svc_i3c_xfer {
137 	struct list_head node;
138 	struct completion comp;
139 	int ret;
140 	unsigned int type;
141 	unsigned int ncmds;
142 	struct svc_i3c_cmd cmds[];
143 };
144 
145 /**
146  * struct svc_i3c_master - Silvaco I3C Master structure
147  * @base: I3C master controller
148  * @dev: Corresponding device
149  * @regs: Memory mapping
150  * @free_slots: Bit array of available slots
151  * @addrs: Array containing the dynamic addresses of each attached device
152  * @descs: Array of descriptors, one per attached device
153  * @hj_work: Hot-join work
154  * @ibi_work: IBI work
155  * @irq: Main interrupt
156  * @pclk: System clock
157  * @fclk: Fast clock (bus)
158  * @sclk: Slow clock (other events)
159  * @xferqueue: Transfer queue structure
160  * @xferqueue.list: List member
161  * @xferqueue.cur: Current ongoing transfer
162  * @xferqueue.lock: Queue lock
163  * @ibi: IBI structure
164  * @ibi.num_slots: Number of slots available in @ibi.slots
165  * @ibi.slots: Available IBI slots
166  * @ibi.tbq_slot: To be queued IBI slot
167  * @ibi.lock: IBI lock
168  */
169 struct svc_i3c_master {
170 	struct i3c_master_controller base;
171 	struct device *dev;
172 	void __iomem *regs;
173 	u32 free_slots;
174 	u8 addrs[SVC_I3C_MAX_DEVS];
175 	struct i3c_dev_desc *descs[SVC_I3C_MAX_DEVS];
176 	struct work_struct hj_work;
177 	struct work_struct ibi_work;
178 	int irq;
179 	struct clk *pclk;
180 	struct clk *fclk;
181 	struct clk *sclk;
182 	struct {
183 		struct list_head list;
184 		struct svc_i3c_xfer *cur;
185 		/* Prevent races between transfers */
186 		spinlock_t lock;
187 	} xferqueue;
188 	struct {
189 		unsigned int num_slots;
190 		struct i3c_dev_desc **slots;
191 		struct i3c_ibi_slot *tbq_slot;
192 		/* Prevent races within IBI handlers */
193 		spinlock_t lock;
194 	} ibi;
195 };
196 
197 /**
198  * struct svc_i3c_i2c_dev_data - Device specific data
199  * @index: Index in the master tables corresponding to this device
200  * @ibi: IBI slot index in the master structure
201  * @ibi_pool: IBI pool associated to this device
202  */
203 struct svc_i3c_i2c_dev_data {
204 	u8 index;
205 	int ibi;
206 	struct i3c_generic_ibi_pool *ibi_pool;
207 };
208 
svc_i3c_master_error(struct svc_i3c_master * master)209 static bool svc_i3c_master_error(struct svc_i3c_master *master)
210 {
211 	u32 mstatus, merrwarn;
212 
213 	mstatus = readl(master->regs + SVC_I3C_MSTATUS);
214 	if (SVC_I3C_MSTATUS_ERRWARN(mstatus)) {
215 		merrwarn = readl(master->regs + SVC_I3C_MERRWARN);
216 		writel(merrwarn, master->regs + SVC_I3C_MERRWARN);
217 		dev_err(master->dev,
218 			"Error condition: MSTATUS 0x%08x, MERRWARN 0x%08x\n",
219 			mstatus, merrwarn);
220 
221 		return true;
222 	}
223 
224 	return false;
225 }
226 
svc_i3c_master_enable_interrupts(struct svc_i3c_master * master,u32 mask)227 static void svc_i3c_master_enable_interrupts(struct svc_i3c_master *master, u32 mask)
228 {
229 	writel(mask, master->regs + SVC_I3C_MINTSET);
230 }
231 
svc_i3c_master_disable_interrupts(struct svc_i3c_master * master)232 static void svc_i3c_master_disable_interrupts(struct svc_i3c_master *master)
233 {
234 	u32 mask = readl(master->regs + SVC_I3C_MINTSET);
235 
236 	writel(mask, master->regs + SVC_I3C_MINTCLR);
237 }
238 
239 static inline struct svc_i3c_master *
to_svc_i3c_master(struct i3c_master_controller * master)240 to_svc_i3c_master(struct i3c_master_controller *master)
241 {
242 	return container_of(master, struct svc_i3c_master, base);
243 }
244 
svc_i3c_master_hj_work(struct work_struct * work)245 static void svc_i3c_master_hj_work(struct work_struct *work)
246 {
247 	struct svc_i3c_master *master;
248 
249 	master = container_of(work, struct svc_i3c_master, hj_work);
250 	i3c_master_do_daa(&master->base);
251 }
252 
253 static struct i3c_dev_desc *
svc_i3c_master_dev_from_addr(struct svc_i3c_master * master,unsigned int ibiaddr)254 svc_i3c_master_dev_from_addr(struct svc_i3c_master *master,
255 			     unsigned int ibiaddr)
256 {
257 	int i;
258 
259 	for (i = 0; i < SVC_I3C_MAX_DEVS; i++)
260 		if (master->addrs[i] == ibiaddr)
261 			break;
262 
263 	if (i == SVC_I3C_MAX_DEVS)
264 		return NULL;
265 
266 	return master->descs[i];
267 }
268 
svc_i3c_master_emit_stop(struct svc_i3c_master * master)269 static void svc_i3c_master_emit_stop(struct svc_i3c_master *master)
270 {
271 	writel(SVC_I3C_MCTRL_REQUEST_STOP, master->regs + SVC_I3C_MCTRL);
272 
273 	/*
274 	 * This delay is necessary after the emission of a stop, otherwise eg.
275 	 * repeating IBIs do not get detected. There is a note in the manual
276 	 * about it, stating that the stop condition might not be settled
277 	 * correctly if a start condition follows too rapidly.
278 	 */
279 	udelay(1);
280 }
281 
svc_i3c_master_clear_merrwarn(struct svc_i3c_master * master)282 static void svc_i3c_master_clear_merrwarn(struct svc_i3c_master *master)
283 {
284 	writel(readl(master->regs + SVC_I3C_MERRWARN),
285 	       master->regs + SVC_I3C_MERRWARN);
286 }
287 
svc_i3c_master_handle_ibi(struct svc_i3c_master * master,struct i3c_dev_desc * dev)288 static int svc_i3c_master_handle_ibi(struct svc_i3c_master *master,
289 				     struct i3c_dev_desc *dev)
290 {
291 	struct svc_i3c_i2c_dev_data *data = i3c_dev_get_master_data(dev);
292 	struct i3c_ibi_slot *slot;
293 	unsigned int count;
294 	u32 mdatactrl;
295 	u8 *buf;
296 
297 	slot = i3c_generic_ibi_get_free_slot(data->ibi_pool);
298 	if (!slot)
299 		return -ENOSPC;
300 
301 	slot->len = 0;
302 	buf = slot->data;
303 
304 	while (SVC_I3C_MSTATUS_RXPEND(readl(master->regs + SVC_I3C_MSTATUS))  &&
305 	       slot->len < SVC_I3C_FIFO_SIZE) {
306 		mdatactrl = readl(master->regs + SVC_I3C_MDATACTRL);
307 		count = SVC_I3C_MDATACTRL_RXCOUNT(mdatactrl);
308 		readsl(master->regs + SVC_I3C_MRDATAB, buf, count);
309 		slot->len += count;
310 		buf += count;
311 	}
312 
313 	master->ibi.tbq_slot = slot;
314 
315 	return 0;
316 }
317 
svc_i3c_master_ack_ibi(struct svc_i3c_master * master,bool mandatory_byte)318 static void svc_i3c_master_ack_ibi(struct svc_i3c_master *master,
319 				   bool mandatory_byte)
320 {
321 	unsigned int ibi_ack_nack;
322 
323 	ibi_ack_nack = SVC_I3C_MCTRL_REQUEST_IBI_ACKNACK;
324 	if (mandatory_byte)
325 		ibi_ack_nack |= SVC_I3C_MCTRL_IBIRESP_ACK_WITH_BYTE;
326 	else
327 		ibi_ack_nack |= SVC_I3C_MCTRL_IBIRESP_ACK_WITHOUT_BYTE;
328 
329 	writel(ibi_ack_nack, master->regs + SVC_I3C_MCTRL);
330 }
331 
svc_i3c_master_nack_ibi(struct svc_i3c_master * master)332 static void svc_i3c_master_nack_ibi(struct svc_i3c_master *master)
333 {
334 	writel(SVC_I3C_MCTRL_REQUEST_IBI_ACKNACK |
335 	       SVC_I3C_MCTRL_IBIRESP_NACK,
336 	       master->regs + SVC_I3C_MCTRL);
337 }
338 
svc_i3c_master_ibi_work(struct work_struct * work)339 static void svc_i3c_master_ibi_work(struct work_struct *work)
340 {
341 	struct svc_i3c_master *master = container_of(work, struct svc_i3c_master, ibi_work);
342 	struct svc_i3c_i2c_dev_data *data;
343 	unsigned int ibitype, ibiaddr;
344 	struct i3c_dev_desc *dev;
345 	u32 status, val;
346 	int ret;
347 
348 	/* Acknowledge the incoming interrupt with the AUTOIBI mechanism */
349 	writel(SVC_I3C_MCTRL_REQUEST_AUTO_IBI |
350 	       SVC_I3C_MCTRL_IBIRESP_AUTO,
351 	       master->regs + SVC_I3C_MCTRL);
352 
353 	/* Wait for IBIWON, should take approximately 100us */
354 	ret = readl_relaxed_poll_timeout(master->regs + SVC_I3C_MSTATUS, val,
355 					 SVC_I3C_MSTATUS_IBIWON(val), 0, 1000);
356 	if (ret) {
357 		dev_err(master->dev, "Timeout when polling for IBIWON\n");
358 		goto reenable_ibis;
359 	}
360 
361 	/* Clear the interrupt status */
362 	writel(SVC_I3C_MINT_IBIWON, master->regs + SVC_I3C_MSTATUS);
363 
364 	status = readl(master->regs + SVC_I3C_MSTATUS);
365 	ibitype = SVC_I3C_MSTATUS_IBITYPE(status);
366 	ibiaddr = SVC_I3C_MSTATUS_IBIADDR(status);
367 
368 	/* Handle the critical responses to IBI's */
369 	switch (ibitype) {
370 	case SVC_I3C_MSTATUS_IBITYPE_IBI:
371 		dev = svc_i3c_master_dev_from_addr(master, ibiaddr);
372 		if (!dev)
373 			svc_i3c_master_nack_ibi(master);
374 		else
375 			svc_i3c_master_handle_ibi(master, dev);
376 		break;
377 	case SVC_I3C_MSTATUS_IBITYPE_HOT_JOIN:
378 		svc_i3c_master_ack_ibi(master, false);
379 		break;
380 	case SVC_I3C_MSTATUS_IBITYPE_MASTER_REQUEST:
381 		svc_i3c_master_nack_ibi(master);
382 		break;
383 	default:
384 		break;
385 	}
386 
387 	/*
388 	 * If an error happened, we probably got interrupted and the exchange
389 	 * timedout. In this case we just drop everything, emit a stop and wait
390 	 * for the slave to interrupt again.
391 	 */
392 	if (svc_i3c_master_error(master)) {
393 		if (master->ibi.tbq_slot) {
394 			data = i3c_dev_get_master_data(dev);
395 			i3c_generic_ibi_recycle_slot(data->ibi_pool,
396 						     master->ibi.tbq_slot);
397 			master->ibi.tbq_slot = NULL;
398 		}
399 
400 		svc_i3c_master_emit_stop(master);
401 
402 		goto reenable_ibis;
403 	}
404 
405 	/* Handle the non critical tasks */
406 	switch (ibitype) {
407 	case SVC_I3C_MSTATUS_IBITYPE_IBI:
408 		if (dev) {
409 			i3c_master_queue_ibi(dev, master->ibi.tbq_slot);
410 			master->ibi.tbq_slot = NULL;
411 		}
412 		svc_i3c_master_emit_stop(master);
413 		break;
414 	case SVC_I3C_MSTATUS_IBITYPE_HOT_JOIN:
415 		queue_work(master->base.wq, &master->hj_work);
416 		break;
417 	case SVC_I3C_MSTATUS_IBITYPE_MASTER_REQUEST:
418 	default:
419 		break;
420 	}
421 
422 reenable_ibis:
423 	svc_i3c_master_enable_interrupts(master, SVC_I3C_MINT_SLVSTART);
424 }
425 
svc_i3c_master_irq_handler(int irq,void * dev_id)426 static irqreturn_t svc_i3c_master_irq_handler(int irq, void *dev_id)
427 {
428 	struct svc_i3c_master *master = (struct svc_i3c_master *)dev_id;
429 	u32 active = readl(master->regs + SVC_I3C_MINTMASKED);
430 
431 	if (!SVC_I3C_MSTATUS_SLVSTART(active))
432 		return IRQ_NONE;
433 
434 	/* Clear the interrupt status */
435 	writel(SVC_I3C_MINT_SLVSTART, master->regs + SVC_I3C_MSTATUS);
436 
437 	svc_i3c_master_disable_interrupts(master);
438 
439 	/* Handle the interrupt in a non atomic context */
440 	queue_work(master->base.wq, &master->ibi_work);
441 
442 	return IRQ_HANDLED;
443 }
444 
svc_i3c_master_bus_init(struct i3c_master_controller * m)445 static int svc_i3c_master_bus_init(struct i3c_master_controller *m)
446 {
447 	struct svc_i3c_master *master = to_svc_i3c_master(m);
448 	struct i3c_bus *bus = i3c_master_get_bus(m);
449 	struct i3c_device_info info = {};
450 	unsigned long fclk_rate, fclk_period_ns;
451 	unsigned int high_period_ns, od_low_period_ns;
452 	u32 ppbaud, pplow, odhpp, odbaud, i2cbaud, reg;
453 	int ret;
454 
455 	/* Timings derivation */
456 	fclk_rate = clk_get_rate(master->fclk);
457 	if (!fclk_rate)
458 		return -EINVAL;
459 
460 	fclk_period_ns = DIV_ROUND_UP(1000000000, fclk_rate);
461 
462 	/*
463 	 * Using I3C Push-Pull mode, target is 12.5MHz/80ns period.
464 	 * Simplest configuration is using a 50% duty-cycle of 40ns.
465 	 */
466 	ppbaud = DIV_ROUND_UP(40, fclk_period_ns) - 1;
467 	pplow = 0;
468 
469 	/*
470 	 * Using I3C Open-Drain mode, target is 4.17MHz/240ns with a
471 	 * duty-cycle tuned so that high levels are filetered out by
472 	 * the 50ns filter (target being 40ns).
473 	 */
474 	odhpp = 1;
475 	high_period_ns = (ppbaud + 1) * fclk_period_ns;
476 	odbaud = DIV_ROUND_UP(240 - high_period_ns, high_period_ns) - 1;
477 	od_low_period_ns = (odbaud + 1) * high_period_ns;
478 
479 	switch (bus->mode) {
480 	case I3C_BUS_MODE_PURE:
481 		i2cbaud = 0;
482 		break;
483 	case I3C_BUS_MODE_MIXED_FAST:
484 	case I3C_BUS_MODE_MIXED_LIMITED:
485 		/*
486 		 * Using I2C Fm+ mode, target is 1MHz/1000ns, the difference
487 		 * between the high and low period does not really matter.
488 		 */
489 		i2cbaud = DIV_ROUND_UP(1000, od_low_period_ns) - 2;
490 		break;
491 	case I3C_BUS_MODE_MIXED_SLOW:
492 		/*
493 		 * Using I2C Fm mode, target is 0.4MHz/2500ns, with the same
494 		 * constraints as the FM+ mode.
495 		 */
496 		i2cbaud = DIV_ROUND_UP(2500, od_low_period_ns) - 2;
497 		break;
498 	default:
499 		return -EINVAL;
500 	}
501 
502 	reg = SVC_I3C_MCONFIG_MASTER_EN |
503 	      SVC_I3C_MCONFIG_DISTO(0) |
504 	      SVC_I3C_MCONFIG_HKEEP(0) |
505 	      SVC_I3C_MCONFIG_ODSTOP(0) |
506 	      SVC_I3C_MCONFIG_PPBAUD(ppbaud) |
507 	      SVC_I3C_MCONFIG_PPLOW(pplow) |
508 	      SVC_I3C_MCONFIG_ODBAUD(odbaud) |
509 	      SVC_I3C_MCONFIG_ODHPP(odhpp) |
510 	      SVC_I3C_MCONFIG_SKEW(0) |
511 	      SVC_I3C_MCONFIG_I2CBAUD(i2cbaud);
512 	writel(reg, master->regs + SVC_I3C_MCONFIG);
513 
514 	/* Master core's registration */
515 	ret = i3c_master_get_free_addr(m, 0);
516 	if (ret < 0)
517 		return ret;
518 
519 	info.dyn_addr = ret;
520 
521 	writel(SVC_MDYNADDR_VALID | SVC_MDYNADDR_ADDR(info.dyn_addr),
522 	       master->regs + SVC_I3C_MDYNADDR);
523 
524 	ret = i3c_master_set_info(&master->base, &info);
525 	if (ret)
526 		return ret;
527 
528 	svc_i3c_master_enable_interrupts(master, SVC_I3C_MINT_SLVSTART);
529 
530 	return 0;
531 }
532 
svc_i3c_master_bus_cleanup(struct i3c_master_controller * m)533 static void svc_i3c_master_bus_cleanup(struct i3c_master_controller *m)
534 {
535 	struct svc_i3c_master *master = to_svc_i3c_master(m);
536 
537 	svc_i3c_master_disable_interrupts(master);
538 
539 	/* Disable master */
540 	writel(0, master->regs + SVC_I3C_MCONFIG);
541 }
542 
svc_i3c_master_reserve_slot(struct svc_i3c_master * master)543 static int svc_i3c_master_reserve_slot(struct svc_i3c_master *master)
544 {
545 	unsigned int slot;
546 
547 	if (!(master->free_slots & GENMASK(SVC_I3C_MAX_DEVS - 1, 0)))
548 		return -ENOSPC;
549 
550 	slot = ffs(master->free_slots) - 1;
551 
552 	master->free_slots &= ~BIT(slot);
553 
554 	return slot;
555 }
556 
svc_i3c_master_release_slot(struct svc_i3c_master * master,unsigned int slot)557 static void svc_i3c_master_release_slot(struct svc_i3c_master *master,
558 					unsigned int slot)
559 {
560 	master->free_slots |= BIT(slot);
561 }
562 
svc_i3c_master_attach_i3c_dev(struct i3c_dev_desc * dev)563 static int svc_i3c_master_attach_i3c_dev(struct i3c_dev_desc *dev)
564 {
565 	struct i3c_master_controller *m = i3c_dev_get_master(dev);
566 	struct svc_i3c_master *master = to_svc_i3c_master(m);
567 	struct svc_i3c_i2c_dev_data *data;
568 	int slot;
569 
570 	slot = svc_i3c_master_reserve_slot(master);
571 	if (slot < 0)
572 		return slot;
573 
574 	data = kzalloc(sizeof(*data), GFP_KERNEL);
575 	if (!data) {
576 		svc_i3c_master_release_slot(master, slot);
577 		return -ENOMEM;
578 	}
579 
580 	data->ibi = -1;
581 	data->index = slot;
582 	master->addrs[slot] = dev->info.dyn_addr ? dev->info.dyn_addr :
583 						   dev->info.static_addr;
584 	master->descs[slot] = dev;
585 
586 	i3c_dev_set_master_data(dev, data);
587 
588 	return 0;
589 }
590 
svc_i3c_master_reattach_i3c_dev(struct i3c_dev_desc * dev,u8 old_dyn_addr)591 static int svc_i3c_master_reattach_i3c_dev(struct i3c_dev_desc *dev,
592 					   u8 old_dyn_addr)
593 {
594 	struct i3c_master_controller *m = i3c_dev_get_master(dev);
595 	struct svc_i3c_master *master = to_svc_i3c_master(m);
596 	struct svc_i3c_i2c_dev_data *data = i3c_dev_get_master_data(dev);
597 
598 	master->addrs[data->index] = dev->info.dyn_addr ? dev->info.dyn_addr :
599 							  dev->info.static_addr;
600 
601 	return 0;
602 }
603 
svc_i3c_master_detach_i3c_dev(struct i3c_dev_desc * dev)604 static void svc_i3c_master_detach_i3c_dev(struct i3c_dev_desc *dev)
605 {
606 	struct svc_i3c_i2c_dev_data *data = i3c_dev_get_master_data(dev);
607 	struct i3c_master_controller *m = i3c_dev_get_master(dev);
608 	struct svc_i3c_master *master = to_svc_i3c_master(m);
609 
610 	master->addrs[data->index] = 0;
611 	svc_i3c_master_release_slot(master, data->index);
612 
613 	kfree(data);
614 }
615 
svc_i3c_master_attach_i2c_dev(struct i2c_dev_desc * dev)616 static int svc_i3c_master_attach_i2c_dev(struct i2c_dev_desc *dev)
617 {
618 	struct i3c_master_controller *m = i2c_dev_get_master(dev);
619 	struct svc_i3c_master *master = to_svc_i3c_master(m);
620 	struct svc_i3c_i2c_dev_data *data;
621 	int slot;
622 
623 	slot = svc_i3c_master_reserve_slot(master);
624 	if (slot < 0)
625 		return slot;
626 
627 	data = kzalloc(sizeof(*data), GFP_KERNEL);
628 	if (!data) {
629 		svc_i3c_master_release_slot(master, slot);
630 		return -ENOMEM;
631 	}
632 
633 	data->index = slot;
634 	master->addrs[slot] = dev->addr;
635 
636 	i2c_dev_set_master_data(dev, data);
637 
638 	return 0;
639 }
640 
svc_i3c_master_detach_i2c_dev(struct i2c_dev_desc * dev)641 static void svc_i3c_master_detach_i2c_dev(struct i2c_dev_desc *dev)
642 {
643 	struct svc_i3c_i2c_dev_data *data = i2c_dev_get_master_data(dev);
644 	struct i3c_master_controller *m = i2c_dev_get_master(dev);
645 	struct svc_i3c_master *master = to_svc_i3c_master(m);
646 
647 	svc_i3c_master_release_slot(master, data->index);
648 
649 	kfree(data);
650 }
651 
svc_i3c_master_readb(struct svc_i3c_master * master,u8 * dst,unsigned int len)652 static int svc_i3c_master_readb(struct svc_i3c_master *master, u8 *dst,
653 				unsigned int len)
654 {
655 	int ret, i;
656 	u32 reg;
657 
658 	for (i = 0; i < len; i++) {
659 		ret = readl_poll_timeout(master->regs + SVC_I3C_MSTATUS, reg,
660 					 SVC_I3C_MSTATUS_RXPEND(reg), 0, 1000);
661 		if (ret)
662 			return ret;
663 
664 		dst[i] = readl(master->regs + SVC_I3C_MRDATAB);
665 	}
666 
667 	return 0;
668 }
669 
svc_i3c_master_do_daa_locked(struct svc_i3c_master * master,u8 * addrs,unsigned int * count)670 static int svc_i3c_master_do_daa_locked(struct svc_i3c_master *master,
671 					u8 *addrs, unsigned int *count)
672 {
673 	u64 prov_id[SVC_I3C_MAX_DEVS] = {}, nacking_prov_id = 0;
674 	unsigned int dev_nb = 0, last_addr = 0;
675 	u32 reg;
676 	int ret, i;
677 
678 	while (true) {
679 		/* Enter/proceed with DAA */
680 		writel(SVC_I3C_MCTRL_REQUEST_PROC_DAA |
681 		       SVC_I3C_MCTRL_TYPE_I3C |
682 		       SVC_I3C_MCTRL_IBIRESP_NACK |
683 		       SVC_I3C_MCTRL_DIR(SVC_I3C_MCTRL_DIR_WRITE),
684 		       master->regs + SVC_I3C_MCTRL);
685 
686 		/*
687 		 * Either one slave will send its ID, or the assignment process
688 		 * is done.
689 		 */
690 		ret = readl_poll_timeout(master->regs + SVC_I3C_MSTATUS, reg,
691 					 SVC_I3C_MSTATUS_RXPEND(reg) |
692 					 SVC_I3C_MSTATUS_MCTRLDONE(reg),
693 					 1, 1000);
694 		if (ret)
695 			return ret;
696 
697 		if (SVC_I3C_MSTATUS_RXPEND(reg)) {
698 			u8 data[6];
699 
700 			/*
701 			 * We only care about the 48-bit provisional ID yet to
702 			 * be sure a device does not nack an address twice.
703 			 * Otherwise, we would just need to flush the RX FIFO.
704 			 */
705 			ret = svc_i3c_master_readb(master, data, 6);
706 			if (ret)
707 				return ret;
708 
709 			for (i = 0; i < 6; i++)
710 				prov_id[dev_nb] |= (u64)(data[i]) << (8 * (5 - i));
711 
712 			/* We do not care about the BCR and DCR yet */
713 			ret = svc_i3c_master_readb(master, data, 2);
714 			if (ret)
715 				return ret;
716 		} else if (SVC_I3C_MSTATUS_MCTRLDONE(reg)) {
717 			if (SVC_I3C_MSTATUS_STATE_IDLE(reg) &&
718 			    SVC_I3C_MSTATUS_COMPLETE(reg)) {
719 				/*
720 				 * All devices received and acked they dynamic
721 				 * address, this is the natural end of the DAA
722 				 * procedure.
723 				 */
724 				break;
725 			} else if (SVC_I3C_MSTATUS_NACKED(reg)) {
726 				/*
727 				 * A slave device nacked the address, this is
728 				 * allowed only once, DAA will be stopped and
729 				 * then resumed. The same device is supposed to
730 				 * answer again immediately and shall ack the
731 				 * address this time.
732 				 */
733 				if (prov_id[dev_nb] == nacking_prov_id)
734 					return -EIO;
735 
736 				dev_nb--;
737 				nacking_prov_id = prov_id[dev_nb];
738 				svc_i3c_master_emit_stop(master);
739 
740 				continue;
741 			} else {
742 				return -EIO;
743 			}
744 		}
745 
746 		/* Wait for the slave to be ready to receive its address */
747 		ret = readl_poll_timeout(master->regs + SVC_I3C_MSTATUS, reg,
748 					 SVC_I3C_MSTATUS_MCTRLDONE(reg) &&
749 					 SVC_I3C_MSTATUS_STATE_DAA(reg) &&
750 					 SVC_I3C_MSTATUS_BETWEEN(reg),
751 					 0, 1000);
752 		if (ret)
753 			return ret;
754 
755 		/* Give the slave device a suitable dynamic address */
756 		ret = i3c_master_get_free_addr(&master->base, last_addr + 1);
757 		if (ret < 0)
758 			return ret;
759 
760 		addrs[dev_nb] = ret;
761 		dev_dbg(master->dev, "DAA: device %d assigned to 0x%02x\n",
762 			dev_nb, addrs[dev_nb]);
763 
764 		writel(addrs[dev_nb], master->regs + SVC_I3C_MWDATAB);
765 		last_addr = addrs[dev_nb++];
766 	}
767 
768 	*count = dev_nb;
769 
770 	return 0;
771 }
772 
svc_i3c_update_ibirules(struct svc_i3c_master * master)773 static int svc_i3c_update_ibirules(struct svc_i3c_master *master)
774 {
775 	struct i3c_dev_desc *dev;
776 	u32 reg_mbyte = 0, reg_nobyte = SVC_I3C_IBIRULES_NOBYTE;
777 	unsigned int mbyte_addr_ok = 0, mbyte_addr_ko = 0, nobyte_addr_ok = 0,
778 		nobyte_addr_ko = 0;
779 	bool list_mbyte = false, list_nobyte = false;
780 
781 	/* Create the IBIRULES register for both cases */
782 	i3c_bus_for_each_i3cdev(&master->base.bus, dev) {
783 		if (I3C_BCR_DEVICE_ROLE(dev->info.bcr) == I3C_BCR_I3C_MASTER)
784 			continue;
785 
786 		if (dev->info.bcr & I3C_BCR_IBI_PAYLOAD) {
787 			reg_mbyte |= SVC_I3C_IBIRULES_ADDR(mbyte_addr_ok,
788 							   dev->info.dyn_addr);
789 
790 			/* IBI rules cannot be applied to devices with MSb=1 */
791 			if (dev->info.dyn_addr & BIT(7))
792 				mbyte_addr_ko++;
793 			else
794 				mbyte_addr_ok++;
795 		} else {
796 			reg_nobyte |= SVC_I3C_IBIRULES_ADDR(nobyte_addr_ok,
797 							    dev->info.dyn_addr);
798 
799 			/* IBI rules cannot be applied to devices with MSb=1 */
800 			if (dev->info.dyn_addr & BIT(7))
801 				nobyte_addr_ko++;
802 			else
803 				nobyte_addr_ok++;
804 		}
805 	}
806 
807 	/* Device list cannot be handled by hardware */
808 	if (!mbyte_addr_ko && mbyte_addr_ok <= SVC_I3C_IBIRULES_ADDRS)
809 		list_mbyte = true;
810 
811 	if (!nobyte_addr_ko && nobyte_addr_ok <= SVC_I3C_IBIRULES_ADDRS)
812 		list_nobyte = true;
813 
814 	/* No list can be properly handled, return an error */
815 	if (!list_mbyte && !list_nobyte)
816 		return -ERANGE;
817 
818 	/* Pick the first list that can be handled by hardware, randomly */
819 	if (list_mbyte)
820 		writel(reg_mbyte, master->regs + SVC_I3C_IBIRULES);
821 	else
822 		writel(reg_nobyte, master->regs + SVC_I3C_IBIRULES);
823 
824 	return 0;
825 }
826 
svc_i3c_master_do_daa(struct i3c_master_controller * m)827 static int svc_i3c_master_do_daa(struct i3c_master_controller *m)
828 {
829 	struct svc_i3c_master *master = to_svc_i3c_master(m);
830 	u8 addrs[SVC_I3C_MAX_DEVS];
831 	unsigned long flags;
832 	unsigned int dev_nb;
833 	int ret, i;
834 
835 	spin_lock_irqsave(&master->xferqueue.lock, flags);
836 	ret = svc_i3c_master_do_daa_locked(master, addrs, &dev_nb);
837 	spin_unlock_irqrestore(&master->xferqueue.lock, flags);
838 	if (ret)
839 		goto emit_stop;
840 
841 	/* Register all devices who participated to the core */
842 	for (i = 0; i < dev_nb; i++) {
843 		ret = i3c_master_add_i3c_dev_locked(m, addrs[i]);
844 		if (ret)
845 			return ret;
846 	}
847 
848 	/* Configure IBI auto-rules */
849 	ret = svc_i3c_update_ibirules(master);
850 	if (ret) {
851 		dev_err(master->dev, "Cannot handle such a list of devices");
852 		return ret;
853 	}
854 
855 	return 0;
856 
857 emit_stop:
858 	svc_i3c_master_emit_stop(master);
859 	svc_i3c_master_clear_merrwarn(master);
860 
861 	return ret;
862 }
863 
svc_i3c_master_read(struct svc_i3c_master * master,u8 * in,unsigned int len)864 static int svc_i3c_master_read(struct svc_i3c_master *master,
865 			       u8 *in, unsigned int len)
866 {
867 	int offset = 0, i, ret;
868 	u32 mdctrl;
869 
870 	while (offset < len) {
871 		unsigned int count;
872 
873 		ret = readl_poll_timeout(master->regs + SVC_I3C_MDATACTRL,
874 					 mdctrl,
875 					 !(mdctrl & SVC_I3C_MDATACTRL_RXEMPTY),
876 					 0, 1000);
877 		if (ret)
878 			return ret;
879 
880 		count = SVC_I3C_MDATACTRL_RXCOUNT(mdctrl);
881 		for (i = 0; i < count; i++)
882 			in[offset + i] = readl(master->regs + SVC_I3C_MRDATAB);
883 
884 		offset += count;
885 	}
886 
887 	return 0;
888 }
889 
svc_i3c_master_write(struct svc_i3c_master * master,const u8 * out,unsigned int len)890 static int svc_i3c_master_write(struct svc_i3c_master *master,
891 				const u8 *out, unsigned int len)
892 {
893 	int offset = 0, ret;
894 	u32 mdctrl;
895 
896 	while (offset < len) {
897 		ret = readl_poll_timeout(master->regs + SVC_I3C_MDATACTRL,
898 					 mdctrl,
899 					 !(mdctrl & SVC_I3C_MDATACTRL_TXFULL),
900 					 0, 1000);
901 		if (ret)
902 			return ret;
903 
904 		/*
905 		 * The last byte to be sent over the bus must either have the
906 		 * "end" bit set or be written in MWDATABE.
907 		 */
908 		if (likely(offset < (len - 1)))
909 			writel(out[offset++], master->regs + SVC_I3C_MWDATAB);
910 		else
911 			writel(out[offset++], master->regs + SVC_I3C_MWDATABE);
912 	}
913 
914 	return 0;
915 }
916 
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 read_len,bool continued)917 static int svc_i3c_master_xfer(struct svc_i3c_master *master,
918 			       bool rnw, unsigned int xfer_type, u8 addr,
919 			       u8 *in, const u8 *out, unsigned int xfer_len,
920 			       unsigned int read_len, bool continued)
921 {
922 	u32 reg;
923 	int ret;
924 
925 	writel(SVC_I3C_MCTRL_REQUEST_START_ADDR |
926 	       xfer_type |
927 	       SVC_I3C_MCTRL_IBIRESP_NACK |
928 	       SVC_I3C_MCTRL_DIR(rnw) |
929 	       SVC_I3C_MCTRL_ADDR(addr) |
930 	       SVC_I3C_MCTRL_RDTERM(read_len),
931 	       master->regs + SVC_I3C_MCTRL);
932 
933 	ret = readl_poll_timeout(master->regs + SVC_I3C_MSTATUS, reg,
934 				 SVC_I3C_MSTATUS_MCTRLDONE(reg), 0, 1000);
935 	if (ret)
936 		goto emit_stop;
937 
938 	if (rnw)
939 		ret = svc_i3c_master_read(master, in, xfer_len);
940 	else
941 		ret = svc_i3c_master_write(master, out, xfer_len);
942 	if (ret)
943 		goto emit_stop;
944 
945 	ret = readl_poll_timeout(master->regs + SVC_I3C_MSTATUS, reg,
946 				 SVC_I3C_MSTATUS_COMPLETE(reg), 0, 1000);
947 	if (ret)
948 		goto emit_stop;
949 
950 	if (!continued)
951 		svc_i3c_master_emit_stop(master);
952 
953 	return 0;
954 
955 emit_stop:
956 	svc_i3c_master_emit_stop(master);
957 	svc_i3c_master_clear_merrwarn(master);
958 
959 	return ret;
960 }
961 
962 static struct svc_i3c_xfer *
svc_i3c_master_alloc_xfer(struct svc_i3c_master * master,unsigned int ncmds)963 svc_i3c_master_alloc_xfer(struct svc_i3c_master *master, unsigned int ncmds)
964 {
965 	struct svc_i3c_xfer *xfer;
966 
967 	xfer = kzalloc(struct_size(xfer, cmds, ncmds), GFP_KERNEL);
968 	if (!xfer)
969 		return NULL;
970 
971 	INIT_LIST_HEAD(&xfer->node);
972 	xfer->ncmds = ncmds;
973 	xfer->ret = -ETIMEDOUT;
974 
975 	return xfer;
976 }
977 
svc_i3c_master_free_xfer(struct svc_i3c_xfer * xfer)978 static void svc_i3c_master_free_xfer(struct svc_i3c_xfer *xfer)
979 {
980 	kfree(xfer);
981 }
982 
svc_i3c_master_dequeue_xfer_locked(struct svc_i3c_master * master,struct svc_i3c_xfer * xfer)983 static void svc_i3c_master_dequeue_xfer_locked(struct svc_i3c_master *master,
984 					       struct svc_i3c_xfer *xfer)
985 {
986 	if (master->xferqueue.cur == xfer)
987 		master->xferqueue.cur = NULL;
988 	else
989 		list_del_init(&xfer->node);
990 }
991 
svc_i3c_master_dequeue_xfer(struct svc_i3c_master * master,struct svc_i3c_xfer * xfer)992 static void svc_i3c_master_dequeue_xfer(struct svc_i3c_master *master,
993 					struct svc_i3c_xfer *xfer)
994 {
995 	unsigned long flags;
996 
997 	spin_lock_irqsave(&master->xferqueue.lock, flags);
998 	svc_i3c_master_dequeue_xfer_locked(master, xfer);
999 	spin_unlock_irqrestore(&master->xferqueue.lock, flags);
1000 }
1001 
svc_i3c_master_start_xfer_locked(struct svc_i3c_master * master)1002 static void svc_i3c_master_start_xfer_locked(struct svc_i3c_master *master)
1003 {
1004 	struct svc_i3c_xfer *xfer = master->xferqueue.cur;
1005 	int ret, i;
1006 
1007 	if (!xfer)
1008 		return;
1009 
1010 	for (i = 0; i < xfer->ncmds; i++) {
1011 		struct svc_i3c_cmd *cmd = &xfer->cmds[i];
1012 
1013 		ret = svc_i3c_master_xfer(master, cmd->rnw, xfer->type,
1014 					  cmd->addr, cmd->in, cmd->out,
1015 					  cmd->len, cmd->read_len,
1016 					  cmd->continued);
1017 		if (ret)
1018 			break;
1019 	}
1020 
1021 	xfer->ret = ret;
1022 	complete(&xfer->comp);
1023 
1024 	if (ret < 0)
1025 		svc_i3c_master_dequeue_xfer_locked(master, xfer);
1026 
1027 	xfer = list_first_entry_or_null(&master->xferqueue.list,
1028 					struct svc_i3c_xfer,
1029 					node);
1030 	if (xfer)
1031 		list_del_init(&xfer->node);
1032 
1033 	master->xferqueue.cur = xfer;
1034 	svc_i3c_master_start_xfer_locked(master);
1035 }
1036 
svc_i3c_master_enqueue_xfer(struct svc_i3c_master * master,struct svc_i3c_xfer * xfer)1037 static void svc_i3c_master_enqueue_xfer(struct svc_i3c_master *master,
1038 					struct svc_i3c_xfer *xfer)
1039 {
1040 	unsigned long flags;
1041 
1042 	init_completion(&xfer->comp);
1043 	spin_lock_irqsave(&master->xferqueue.lock, flags);
1044 	if (master->xferqueue.cur) {
1045 		list_add_tail(&xfer->node, &master->xferqueue.list);
1046 	} else {
1047 		master->xferqueue.cur = xfer;
1048 		svc_i3c_master_start_xfer_locked(master);
1049 	}
1050 	spin_unlock_irqrestore(&master->xferqueue.lock, flags);
1051 }
1052 
1053 static bool
svc_i3c_master_supports_ccc_cmd(struct i3c_master_controller * master,const struct i3c_ccc_cmd * cmd)1054 svc_i3c_master_supports_ccc_cmd(struct i3c_master_controller *master,
1055 				const struct i3c_ccc_cmd *cmd)
1056 {
1057 	/* No software support for CCC commands targeting more than one slave */
1058 	return (cmd->ndests == 1);
1059 }
1060 
svc_i3c_master_send_bdcast_ccc_cmd(struct svc_i3c_master * master,struct i3c_ccc_cmd * ccc)1061 static int svc_i3c_master_send_bdcast_ccc_cmd(struct svc_i3c_master *master,
1062 					      struct i3c_ccc_cmd *ccc)
1063 {
1064 	unsigned int xfer_len = ccc->dests[0].payload.len + 1;
1065 	struct svc_i3c_xfer *xfer;
1066 	struct svc_i3c_cmd *cmd;
1067 	u8 *buf;
1068 	int ret;
1069 
1070 	xfer = svc_i3c_master_alloc_xfer(master, 1);
1071 	if (!xfer)
1072 		return -ENOMEM;
1073 
1074 	buf = kmalloc(xfer_len, GFP_KERNEL);
1075 	if (!buf) {
1076 		svc_i3c_master_free_xfer(xfer);
1077 		return -ENOMEM;
1078 	}
1079 
1080 	buf[0] = ccc->id;
1081 	memcpy(&buf[1], ccc->dests[0].payload.data, ccc->dests[0].payload.len);
1082 
1083 	xfer->type = SVC_I3C_MCTRL_TYPE_I3C;
1084 
1085 	cmd = &xfer->cmds[0];
1086 	cmd->addr = ccc->dests[0].addr;
1087 	cmd->rnw = ccc->rnw;
1088 	cmd->in = NULL;
1089 	cmd->out = buf;
1090 	cmd->len = xfer_len;
1091 	cmd->read_len = 0;
1092 	cmd->continued = false;
1093 
1094 	svc_i3c_master_enqueue_xfer(master, xfer);
1095 	if (!wait_for_completion_timeout(&xfer->comp, msecs_to_jiffies(1000)))
1096 		svc_i3c_master_dequeue_xfer(master, xfer);
1097 
1098 	ret = xfer->ret;
1099 	kfree(buf);
1100 	svc_i3c_master_free_xfer(xfer);
1101 
1102 	return ret;
1103 }
1104 
svc_i3c_master_send_direct_ccc_cmd(struct svc_i3c_master * master,struct i3c_ccc_cmd * ccc)1105 static int svc_i3c_master_send_direct_ccc_cmd(struct svc_i3c_master *master,
1106 					      struct i3c_ccc_cmd *ccc)
1107 {
1108 	unsigned int xfer_len = ccc->dests[0].payload.len;
1109 	unsigned int read_len = ccc->rnw ? xfer_len : 0;
1110 	struct svc_i3c_xfer *xfer;
1111 	struct svc_i3c_cmd *cmd;
1112 	int ret;
1113 
1114 	xfer = svc_i3c_master_alloc_xfer(master, 2);
1115 	if (!xfer)
1116 		return -ENOMEM;
1117 
1118 	xfer->type = SVC_I3C_MCTRL_TYPE_I3C;
1119 
1120 	/* Broadcasted message */
1121 	cmd = &xfer->cmds[0];
1122 	cmd->addr = I3C_BROADCAST_ADDR;
1123 	cmd->rnw = 0;
1124 	cmd->in = NULL;
1125 	cmd->out = &ccc->id;
1126 	cmd->len = 1;
1127 	cmd->read_len = 0;
1128 	cmd->continued = true;
1129 
1130 	/* Directed message */
1131 	cmd = &xfer->cmds[1];
1132 	cmd->addr = ccc->dests[0].addr;
1133 	cmd->rnw = ccc->rnw;
1134 	cmd->in = ccc->rnw ? ccc->dests[0].payload.data : NULL;
1135 	cmd->out = ccc->rnw ? NULL : ccc->dests[0].payload.data,
1136 	cmd->len = xfer_len;
1137 	cmd->read_len = read_len;
1138 	cmd->continued = false;
1139 
1140 	svc_i3c_master_enqueue_xfer(master, xfer);
1141 	if (!wait_for_completion_timeout(&xfer->comp, msecs_to_jiffies(1000)))
1142 		svc_i3c_master_dequeue_xfer(master, xfer);
1143 
1144 	ret = xfer->ret;
1145 	svc_i3c_master_free_xfer(xfer);
1146 
1147 	return ret;
1148 }
1149 
svc_i3c_master_send_ccc_cmd(struct i3c_master_controller * m,struct i3c_ccc_cmd * cmd)1150 static int svc_i3c_master_send_ccc_cmd(struct i3c_master_controller *m,
1151 				       struct i3c_ccc_cmd *cmd)
1152 {
1153 	struct svc_i3c_master *master = to_svc_i3c_master(m);
1154 	bool broadcast = cmd->id < 0x80;
1155 
1156 	if (broadcast)
1157 		return svc_i3c_master_send_bdcast_ccc_cmd(master, cmd);
1158 	else
1159 		return svc_i3c_master_send_direct_ccc_cmd(master, cmd);
1160 }
1161 
svc_i3c_master_priv_xfers(struct i3c_dev_desc * dev,struct i3c_priv_xfer * xfers,int nxfers)1162 static int svc_i3c_master_priv_xfers(struct i3c_dev_desc *dev,
1163 				     struct i3c_priv_xfer *xfers,
1164 				     int nxfers)
1165 {
1166 	struct i3c_master_controller *m = i3c_dev_get_master(dev);
1167 	struct svc_i3c_master *master = to_svc_i3c_master(m);
1168 	struct svc_i3c_i2c_dev_data *data = i3c_dev_get_master_data(dev);
1169 	struct svc_i3c_xfer *xfer;
1170 	int ret, i;
1171 
1172 	xfer = svc_i3c_master_alloc_xfer(master, nxfers);
1173 	if (!xfer)
1174 		return -ENOMEM;
1175 
1176 	xfer->type = SVC_I3C_MCTRL_TYPE_I3C;
1177 
1178 	for (i = 0; i < nxfers; i++) {
1179 		struct svc_i3c_cmd *cmd = &xfer->cmds[i];
1180 
1181 		cmd->addr = master->addrs[data->index];
1182 		cmd->rnw = xfers[i].rnw;
1183 		cmd->in = xfers[i].rnw ? xfers[i].data.in : NULL;
1184 		cmd->out = xfers[i].rnw ? NULL : xfers[i].data.out;
1185 		cmd->len = xfers[i].len;
1186 		cmd->read_len = xfers[i].rnw ? xfers[i].len : 0;
1187 		cmd->continued = (i + 1) < nxfers;
1188 	}
1189 
1190 	svc_i3c_master_enqueue_xfer(master, xfer);
1191 	if (!wait_for_completion_timeout(&xfer->comp, msecs_to_jiffies(1000)))
1192 		svc_i3c_master_dequeue_xfer(master, xfer);
1193 
1194 	ret = xfer->ret;
1195 	svc_i3c_master_free_xfer(xfer);
1196 
1197 	return ret;
1198 }
1199 
svc_i3c_master_i2c_xfers(struct i2c_dev_desc * dev,const struct i2c_msg * xfers,int nxfers)1200 static int svc_i3c_master_i2c_xfers(struct i2c_dev_desc *dev,
1201 				    const struct i2c_msg *xfers,
1202 				    int nxfers)
1203 {
1204 	struct i3c_master_controller *m = i2c_dev_get_master(dev);
1205 	struct svc_i3c_master *master = to_svc_i3c_master(m);
1206 	struct svc_i3c_i2c_dev_data *data = i2c_dev_get_master_data(dev);
1207 	struct svc_i3c_xfer *xfer;
1208 	int ret, i;
1209 
1210 	xfer = svc_i3c_master_alloc_xfer(master, nxfers);
1211 	if (!xfer)
1212 		return -ENOMEM;
1213 
1214 	xfer->type = SVC_I3C_MCTRL_TYPE_I2C;
1215 
1216 	for (i = 0; i < nxfers; i++) {
1217 		struct svc_i3c_cmd *cmd = &xfer->cmds[i];
1218 
1219 		cmd->addr = master->addrs[data->index];
1220 		cmd->rnw = xfers[i].flags & I2C_M_RD;
1221 		cmd->in = cmd->rnw ? xfers[i].buf : NULL;
1222 		cmd->out = cmd->rnw ? NULL : xfers[i].buf;
1223 		cmd->len = xfers[i].len;
1224 		cmd->read_len = cmd->rnw ? xfers[i].len : 0;
1225 		cmd->continued = (i + 1 < nxfers);
1226 	}
1227 
1228 	svc_i3c_master_enqueue_xfer(master, xfer);
1229 	if (!wait_for_completion_timeout(&xfer->comp, msecs_to_jiffies(1000)))
1230 		svc_i3c_master_dequeue_xfer(master, xfer);
1231 
1232 	ret = xfer->ret;
1233 	svc_i3c_master_free_xfer(xfer);
1234 
1235 	return ret;
1236 }
1237 
svc_i3c_master_request_ibi(struct i3c_dev_desc * dev,const struct i3c_ibi_setup * req)1238 static int svc_i3c_master_request_ibi(struct i3c_dev_desc *dev,
1239 				      const struct i3c_ibi_setup *req)
1240 {
1241 	struct i3c_master_controller *m = i3c_dev_get_master(dev);
1242 	struct svc_i3c_master *master = to_svc_i3c_master(m);
1243 	struct svc_i3c_i2c_dev_data *data = i3c_dev_get_master_data(dev);
1244 	unsigned long flags;
1245 	unsigned int i;
1246 
1247 	if (dev->ibi->max_payload_len > SVC_I3C_FIFO_SIZE) {
1248 		dev_err(master->dev, "IBI max payload %d should be < %d\n",
1249 			dev->ibi->max_payload_len, SVC_I3C_FIFO_SIZE);
1250 		return -ERANGE;
1251 	}
1252 
1253 	data->ibi_pool = i3c_generic_ibi_alloc_pool(dev, req);
1254 	if (IS_ERR(data->ibi_pool))
1255 		return PTR_ERR(data->ibi_pool);
1256 
1257 	spin_lock_irqsave(&master->ibi.lock, flags);
1258 	for (i = 0; i < master->ibi.num_slots; i++) {
1259 		if (!master->ibi.slots[i]) {
1260 			data->ibi = i;
1261 			master->ibi.slots[i] = dev;
1262 			break;
1263 		}
1264 	}
1265 	spin_unlock_irqrestore(&master->ibi.lock, flags);
1266 
1267 	if (i < master->ibi.num_slots)
1268 		return 0;
1269 
1270 	i3c_generic_ibi_free_pool(data->ibi_pool);
1271 	data->ibi_pool = NULL;
1272 
1273 	return -ENOSPC;
1274 }
1275 
svc_i3c_master_free_ibi(struct i3c_dev_desc * dev)1276 static void svc_i3c_master_free_ibi(struct i3c_dev_desc *dev)
1277 {
1278 	struct i3c_master_controller *m = i3c_dev_get_master(dev);
1279 	struct svc_i3c_master *master = to_svc_i3c_master(m);
1280 	struct svc_i3c_i2c_dev_data *data = i3c_dev_get_master_data(dev);
1281 	unsigned long flags;
1282 
1283 	spin_lock_irqsave(&master->ibi.lock, flags);
1284 	master->ibi.slots[data->ibi] = NULL;
1285 	data->ibi = -1;
1286 	spin_unlock_irqrestore(&master->ibi.lock, flags);
1287 
1288 	i3c_generic_ibi_free_pool(data->ibi_pool);
1289 }
1290 
svc_i3c_master_enable_ibi(struct i3c_dev_desc * dev)1291 static int svc_i3c_master_enable_ibi(struct i3c_dev_desc *dev)
1292 {
1293 	struct i3c_master_controller *m = i3c_dev_get_master(dev);
1294 
1295 	return i3c_master_enec_locked(m, dev->info.dyn_addr, I3C_CCC_EVENT_SIR);
1296 }
1297 
svc_i3c_master_disable_ibi(struct i3c_dev_desc * dev)1298 static int svc_i3c_master_disable_ibi(struct i3c_dev_desc *dev)
1299 {
1300 	struct i3c_master_controller *m = i3c_dev_get_master(dev);
1301 
1302 	return i3c_master_disec_locked(m, dev->info.dyn_addr, I3C_CCC_EVENT_SIR);
1303 }
1304 
svc_i3c_master_recycle_ibi_slot(struct i3c_dev_desc * dev,struct i3c_ibi_slot * slot)1305 static void svc_i3c_master_recycle_ibi_slot(struct i3c_dev_desc *dev,
1306 					    struct i3c_ibi_slot *slot)
1307 {
1308 	struct svc_i3c_i2c_dev_data *data = i3c_dev_get_master_data(dev);
1309 
1310 	i3c_generic_ibi_recycle_slot(data->ibi_pool, slot);
1311 }
1312 
1313 static const struct i3c_master_controller_ops svc_i3c_master_ops = {
1314 	.bus_init = svc_i3c_master_bus_init,
1315 	.bus_cleanup = svc_i3c_master_bus_cleanup,
1316 	.attach_i3c_dev = svc_i3c_master_attach_i3c_dev,
1317 	.detach_i3c_dev = svc_i3c_master_detach_i3c_dev,
1318 	.reattach_i3c_dev = svc_i3c_master_reattach_i3c_dev,
1319 	.attach_i2c_dev = svc_i3c_master_attach_i2c_dev,
1320 	.detach_i2c_dev = svc_i3c_master_detach_i2c_dev,
1321 	.do_daa = svc_i3c_master_do_daa,
1322 	.supports_ccc_cmd = svc_i3c_master_supports_ccc_cmd,
1323 	.send_ccc_cmd = svc_i3c_master_send_ccc_cmd,
1324 	.priv_xfers = svc_i3c_master_priv_xfers,
1325 	.i2c_xfers = svc_i3c_master_i2c_xfers,
1326 	.request_ibi = svc_i3c_master_request_ibi,
1327 	.free_ibi = svc_i3c_master_free_ibi,
1328 	.recycle_ibi_slot = svc_i3c_master_recycle_ibi_slot,
1329 	.enable_ibi = svc_i3c_master_enable_ibi,
1330 	.disable_ibi = svc_i3c_master_disable_ibi,
1331 };
1332 
svc_i3c_master_reset(struct svc_i3c_master * master)1333 static void svc_i3c_master_reset(struct svc_i3c_master *master)
1334 {
1335 	u32 reg;
1336 
1337 	/* Clear pending warnings */
1338 	writel(readl(master->regs + SVC_I3C_MERRWARN),
1339 	       master->regs + SVC_I3C_MERRWARN);
1340 
1341 	/* Set RX and TX tigger levels, flush FIFOs */
1342 	reg = SVC_I3C_MDATACTRL_FLUSHTB |
1343 	      SVC_I3C_MDATACTRL_FLUSHRB |
1344 	      SVC_I3C_MDATACTRL_UNLOCK_TRIG |
1345 	      SVC_I3C_MDATACTRL_TXTRIG_FIFO_NOT_FULL |
1346 	      SVC_I3C_MDATACTRL_RXTRIG_FIFO_NOT_EMPTY;
1347 	writel(reg, master->regs + SVC_I3C_MDATACTRL);
1348 
1349 	svc_i3c_master_disable_interrupts(master);
1350 }
1351 
svc_i3c_master_probe(struct platform_device * pdev)1352 static int svc_i3c_master_probe(struct platform_device *pdev)
1353 {
1354 	struct device *dev = &pdev->dev;
1355 	struct svc_i3c_master *master;
1356 	int ret;
1357 
1358 	master = devm_kzalloc(dev, sizeof(*master), GFP_KERNEL);
1359 	if (!master)
1360 		return -ENOMEM;
1361 
1362 	master->regs = devm_platform_ioremap_resource(pdev, 0);
1363 	if (IS_ERR(master->regs))
1364 		return PTR_ERR(master->regs);
1365 
1366 	master->pclk = devm_clk_get(dev, "pclk");
1367 	if (IS_ERR(master->pclk))
1368 		return PTR_ERR(master->pclk);
1369 
1370 	master->fclk = devm_clk_get(dev, "fast_clk");
1371 	if (IS_ERR(master->fclk))
1372 		return PTR_ERR(master->fclk);
1373 
1374 	master->sclk = devm_clk_get(dev, "slow_clk");
1375 	if (IS_ERR(master->sclk))
1376 		return PTR_ERR(master->sclk);
1377 
1378 	master->irq = platform_get_irq(pdev, 0);
1379 	if (master->irq <= 0)
1380 		return -ENOENT;
1381 
1382 	master->dev = dev;
1383 
1384 	svc_i3c_master_reset(master);
1385 
1386 	ret = clk_prepare_enable(master->pclk);
1387 	if (ret)
1388 		return ret;
1389 
1390 	ret = clk_prepare_enable(master->fclk);
1391 	if (ret)
1392 		goto err_disable_pclk;
1393 
1394 	ret = clk_prepare_enable(master->sclk);
1395 	if (ret)
1396 		goto err_disable_fclk;
1397 
1398 	INIT_WORK(&master->hj_work, svc_i3c_master_hj_work);
1399 	INIT_WORK(&master->ibi_work, svc_i3c_master_ibi_work);
1400 	ret = devm_request_irq(dev, master->irq, svc_i3c_master_irq_handler,
1401 			       IRQF_NO_SUSPEND, "svc-i3c-irq", master);
1402 	if (ret)
1403 		goto err_disable_sclk;
1404 
1405 	master->free_slots = GENMASK(SVC_I3C_MAX_DEVS - 1, 0);
1406 
1407 	spin_lock_init(&master->xferqueue.lock);
1408 	INIT_LIST_HEAD(&master->xferqueue.list);
1409 
1410 	spin_lock_init(&master->ibi.lock);
1411 	master->ibi.num_slots = SVC_I3C_MAX_DEVS;
1412 	master->ibi.slots = devm_kcalloc(&pdev->dev, master->ibi.num_slots,
1413 					 sizeof(*master->ibi.slots),
1414 					 GFP_KERNEL);
1415 	if (!master->ibi.slots) {
1416 		ret = -ENOMEM;
1417 		goto err_disable_sclk;
1418 	}
1419 
1420 	platform_set_drvdata(pdev, master);
1421 
1422 	/* Register the master */
1423 	ret = i3c_master_register(&master->base, &pdev->dev,
1424 				  &svc_i3c_master_ops, false);
1425 	if (ret)
1426 		goto err_disable_sclk;
1427 
1428 	return 0;
1429 
1430 err_disable_sclk:
1431 	clk_disable_unprepare(master->sclk);
1432 
1433 err_disable_fclk:
1434 	clk_disable_unprepare(master->fclk);
1435 
1436 err_disable_pclk:
1437 	clk_disable_unprepare(master->pclk);
1438 
1439 	return ret;
1440 }
1441 
svc_i3c_master_remove(struct platform_device * pdev)1442 static int svc_i3c_master_remove(struct platform_device *pdev)
1443 {
1444 	struct svc_i3c_master *master = platform_get_drvdata(pdev);
1445 	int ret;
1446 
1447 	ret = i3c_master_unregister(&master->base);
1448 	if (ret)
1449 		return ret;
1450 
1451 	clk_disable_unprepare(master->pclk);
1452 	clk_disable_unprepare(master->fclk);
1453 	clk_disable_unprepare(master->sclk);
1454 
1455 	return 0;
1456 }
1457 
1458 static const struct of_device_id svc_i3c_master_of_match_tbl[] = {
1459 	{ .compatible = "silvaco,i3c-master" },
1460 	{ /* sentinel */ },
1461 };
1462 
1463 static struct platform_driver svc_i3c_master = {
1464 	.probe = svc_i3c_master_probe,
1465 	.remove = svc_i3c_master_remove,
1466 	.driver = {
1467 		.name = "silvaco-i3c-master",
1468 		.of_match_table = svc_i3c_master_of_match_tbl,
1469 	},
1470 };
1471 module_platform_driver(svc_i3c_master);
1472 
1473 MODULE_AUTHOR("Conor Culhane <conor.culhane@silvaco.com>");
1474 MODULE_AUTHOR("Miquel Raynal <miquel.raynal@bootlin.com>");
1475 MODULE_DESCRIPTION("Silvaco dual-role I3C master driver");
1476 MODULE_LICENSE("GPL v2");
1477