xref: /linux/drivers/i2c/busses/i2c-qup.c (revision b67ec639010f7d2ce2b467cef36f3e5e785d8d50)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2009-2013, 2016-2018, The Linux Foundation. All rights reserved.
4  * Copyright (c) 2014, Sony Mobile Communications AB.
5  *
6  */
7 
8 #include <linux/acpi.h>
9 #include <linux/atomic.h>
10 #include <linux/clk.h>
11 #include <linux/delay.h>
12 #include <linux/dmaengine.h>
13 #include <linux/dmapool.h>
14 #include <linux/dma-mapping.h>
15 #include <linux/err.h>
16 #include <linux/i2c.h>
17 #include <linux/interconnect.h>
18 #include <linux/interrupt.h>
19 #include <linux/io.h>
20 #include <linux/module.h>
21 #include <linux/platform_device.h>
22 #include <linux/pm_runtime.h>
23 #include <linux/property.h>
24 #include <linux/scatterlist.h>
25 
26 /* QUP Registers */
27 #define QUP_CONFIG		0x000
28 #define QUP_STATE		0x004
29 #define QUP_IO_MODE		0x008
30 #define QUP_SW_RESET		0x00c
31 #define QUP_OPERATIONAL		0x018
32 #define QUP_ERROR_FLAGS		0x01c
33 #define QUP_ERROR_FLAGS_EN	0x020
34 #define QUP_OPERATIONAL_MASK	0x028
35 #define QUP_HW_VERSION		0x030
36 #define QUP_MX_OUTPUT_CNT	0x100
37 #define QUP_OUT_FIFO_BASE	0x110
38 #define QUP_MX_WRITE_CNT	0x150
39 #define QUP_MX_INPUT_CNT	0x200
40 #define QUP_MX_READ_CNT		0x208
41 #define QUP_IN_FIFO_BASE	0x218
42 #define QUP_I2C_CLK_CTL		0x400
43 #define QUP_I2C_STATUS		0x404
44 #define QUP_I2C_MASTER_GEN	0x408
45 
46 /* QUP States and reset values */
47 #define QUP_RESET_STATE		0
48 #define QUP_RUN_STATE		1
49 #define QUP_PAUSE_STATE		3
50 #define QUP_STATE_MASK		3
51 
52 #define QUP_STATE_VALID		BIT(2)
53 #define QUP_I2C_MAST_GEN	BIT(4)
54 #define QUP_I2C_FLUSH		BIT(6)
55 
56 #define QUP_OPERATIONAL_RESET	0x000ff0
57 #define QUP_I2C_STATUS_RESET	0xfffffc
58 
59 /* QUP OPERATIONAL FLAGS */
60 #define QUP_I2C_NACK_FLAG	BIT(3)
61 #define QUP_OUT_NOT_EMPTY	BIT(4)
62 #define QUP_IN_NOT_EMPTY	BIT(5)
63 #define QUP_OUT_FULL		BIT(6)
64 #define QUP_OUT_SVC_FLAG	BIT(8)
65 #define QUP_IN_SVC_FLAG		BIT(9)
66 #define QUP_MX_OUTPUT_DONE	BIT(10)
67 #define QUP_MX_INPUT_DONE	BIT(11)
68 #define OUT_BLOCK_WRITE_REQ	BIT(12)
69 #define IN_BLOCK_READ_REQ	BIT(13)
70 
71 /* I2C mini core related values */
72 #define QUP_NO_INPUT		BIT(7)
73 #define QUP_CLOCK_AUTO_GATE	BIT(13)
74 #define I2C_MINI_CORE		(2 << 8)
75 #define I2C_N_VAL		15
76 #define I2C_N_VAL_V2		7
77 
78 /* Most significant word offset in FIFO port */
79 #define QUP_MSW_SHIFT		(I2C_N_VAL + 1)
80 
81 /* Packing/Unpacking words in FIFOs, and IO modes */
82 #define QUP_OUTPUT_BLK_MODE	(1 << 10)
83 #define QUP_OUTPUT_BAM_MODE	(3 << 10)
84 #define QUP_INPUT_BLK_MODE	(1 << 12)
85 #define QUP_INPUT_BAM_MODE	(3 << 12)
86 #define QUP_BAM_MODE		(QUP_OUTPUT_BAM_MODE | QUP_INPUT_BAM_MODE)
87 #define QUP_UNPACK_EN		BIT(14)
88 #define QUP_PACK_EN		BIT(15)
89 
90 #define QUP_REPACK_EN		(QUP_UNPACK_EN | QUP_PACK_EN)
91 #define QUP_V2_TAGS_EN		1
92 
93 #define QUP_OUTPUT_BLOCK_SIZE(x)(((x) >> 0) & 0x03)
94 #define QUP_OUTPUT_FIFO_SIZE(x)	(((x) >> 2) & 0x07)
95 #define QUP_INPUT_BLOCK_SIZE(x)	(((x) >> 5) & 0x03)
96 #define QUP_INPUT_FIFO_SIZE(x)	(((x) >> 7) & 0x07)
97 
98 /* QUP tags */
99 #define QUP_TAG_START		(1 << 8)
100 #define QUP_TAG_DATA		(2 << 8)
101 #define QUP_TAG_STOP		(3 << 8)
102 #define QUP_TAG_REC		(4 << 8)
103 #define QUP_BAM_INPUT_EOT		0x93
104 #define QUP_BAM_FLUSH_STOP		0x96
105 
106 /* QUP v2 tags */
107 #define QUP_TAG_V2_START               0x81
108 #define QUP_TAG_V2_DATAWR              0x82
109 #define QUP_TAG_V2_DATAWR_STOP         0x83
110 #define QUP_TAG_V2_DATARD              0x85
111 #define QUP_TAG_V2_DATARD_NACK         0x86
112 #define QUP_TAG_V2_DATARD_STOP         0x87
113 
114 /* Status, Error flags */
115 #define I2C_STATUS_WR_BUFFER_FULL	BIT(0)
116 #define I2C_STATUS_BUS_ACTIVE		BIT(8)
117 #define I2C_STATUS_ERROR_MASK		0x38000fc
118 #define QUP_STATUS_ERROR_FLAGS		0x7c
119 
120 #define QUP_READ_LIMIT			256
121 #define SET_BIT				0x1
122 #define RESET_BIT			0x0
123 #define ONE_BYTE			0x1
124 #define QUP_I2C_MX_CONFIG_DURING_RUN   BIT(31)
125 
126 /* Maximum transfer length for single DMA descriptor */
127 #define MX_TX_RX_LEN			SZ_64K
128 #define MX_BLOCKS			(MX_TX_RX_LEN / QUP_READ_LIMIT)
129 /* Maximum transfer length for all DMA descriptors */
130 #define MX_DMA_TX_RX_LEN		(2 * MX_TX_RX_LEN)
131 #define MX_DMA_BLOCKS			(MX_DMA_TX_RX_LEN / QUP_READ_LIMIT)
132 
133 /*
134  * Minimum transfer timeout for i2c transfers in seconds. It will be added on
135  * the top of maximum transfer time calculated from i2c bus speed to compensate
136  * the overheads.
137  */
138 #define TOUT_MIN			2
139 
140 /* Default values. Use these if FW query fails */
141 #define DEFAULT_CLK_FREQ I2C_MAX_STANDARD_MODE_FREQ
142 #define DEFAULT_SRC_CLK 20000000
143 
144 /*
145  * Max tags length (start, stop and maximum 2 bytes address) for each QUP
146  * data transfer
147  */
148 #define QUP_MAX_TAGS_LEN		4
149 /* Max data length for each DATARD tags */
150 #define RECV_MAX_DATA_LEN		254
151 /* TAG length for DATA READ in RX FIFO  */
152 #define READ_RX_TAGS_LEN		2
153 
154 #define QUP_BUS_WIDTH			8
155 
156 static unsigned int scl_freq;
157 module_param_named(scl_freq, scl_freq, uint, 0444);
158 MODULE_PARM_DESC(scl_freq, "SCL frequency override");
159 
160 /*
161  * count: no of blocks
162  * pos: current block number
163  * tx_tag_len: tx tag length for current block
164  * rx_tag_len: rx tag length for current block
165  * data_len: remaining data length for current message
166  * cur_blk_len: data length for current block
167  * total_tx_len: total tx length including tag bytes for current QUP transfer
168  * total_rx_len: total rx length including tag bytes for current QUP transfer
169  * tx_fifo_data_pos: current byte number in TX FIFO word
170  * tx_fifo_free: number of free bytes in current QUP block write.
171  * rx_fifo_data_pos: current byte number in RX FIFO word
172  * fifo_available: number of available bytes in RX FIFO for current
173  *		   QUP block read
174  * tx_fifo_data: QUP TX FIFO write works on word basis (4 bytes). New byte write
175  *		 to TX FIFO will be appended in this data and will be written to
176  *		 TX FIFO when all the 4 bytes are available.
177  * rx_fifo_data: QUP RX FIFO read works on word basis (4 bytes). This will
178  *		 contains the 4 bytes of RX data.
179  * cur_data: pointer to tell cur data position for current message
180  * cur_tx_tags: pointer to tell cur position in tags
181  * tx_tags_sent: all tx tag bytes have been written in FIFO word
182  * send_last_word: for tx FIFO, last word send is pending in current block
183  * rx_bytes_read: if all the bytes have been read from rx FIFO.
184  * rx_tags_fetched: all the rx tag bytes have been fetched from rx fifo word
185  * is_tx_blk_mode: whether tx uses block or FIFO mode in case of non BAM xfer.
186  * is_rx_blk_mode: whether rx uses block or FIFO mode in case of non BAM xfer.
187  * tags: contains tx tag bytes for current QUP transfer
188  */
189 struct qup_i2c_block {
190 	int		count;
191 	int		pos;
192 	int		tx_tag_len;
193 	int		rx_tag_len;
194 	int		data_len;
195 	int		cur_blk_len;
196 	int		total_tx_len;
197 	int		total_rx_len;
198 	int		tx_fifo_data_pos;
199 	int		tx_fifo_free;
200 	int		rx_fifo_data_pos;
201 	int		fifo_available;
202 	u32		tx_fifo_data;
203 	u32		rx_fifo_data;
204 	u8		*cur_data;
205 	u8		*cur_tx_tags;
206 	bool		tx_tags_sent;
207 	bool		send_last_word;
208 	bool		rx_tags_fetched;
209 	bool		rx_bytes_read;
210 	bool		is_tx_blk_mode;
211 	bool		is_rx_blk_mode;
212 	u8		tags[6];
213 };
214 
215 struct qup_i2c_tag {
216 	u8 *start;
217 	dma_addr_t addr;
218 };
219 
220 struct qup_i2c_bam {
221 	struct	qup_i2c_tag tag;
222 	struct	dma_chan *dma;
223 	struct	scatterlist *sg;
224 	unsigned int sg_cnt;
225 };
226 
227 struct qup_i2c_dev {
228 	struct device		*dev;
229 	void __iomem		*base;
230 	int			irq;
231 	struct clk		*clk;
232 	struct clk		*pclk;
233 	struct icc_path		*icc_path;
234 	struct i2c_adapter	adap;
235 
236 	int			clk_ctl;
237 	int			out_fifo_sz;
238 	int			in_fifo_sz;
239 	int			out_blk_sz;
240 	int			in_blk_sz;
241 
242 	int			blk_xfer_limit;
243 	unsigned long		one_byte_t;
244 	unsigned long		xfer_timeout;
245 	struct qup_i2c_block	blk;
246 
247 	struct i2c_msg		*msg;
248 	/* Current posion in user message buffer */
249 	int			pos;
250 	/* I2C protocol errors */
251 	u32			bus_err;
252 	/* QUP core errors */
253 	u32			qup_err;
254 
255 	/* To check if this is the last msg */
256 	bool			is_last;
257 	bool			is_smbus_read;
258 
259 	/* To configure when bus is in run state */
260 	u32			config_run;
261 
262 	/* bandwidth votes */
263 	u32			src_clk_freq;
264 	u32			cur_bw_clk_freq;
265 
266 	/* dma parameters */
267 	bool			is_dma;
268 	/* To check if the current transfer is using DMA */
269 	bool			use_dma;
270 	unsigned int		max_xfer_sg_len;
271 	unsigned int		tag_buf_pos;
272 	/* The threshold length above which block mode will be used */
273 	unsigned int		blk_mode_threshold;
274 	struct			dma_pool *dpool;
275 	struct			qup_i2c_tag start_tag;
276 	struct			qup_i2c_bam brx;
277 	struct			qup_i2c_bam btx;
278 
279 	struct completion	xfer;
280 	/* function to write data in tx fifo */
281 	void (*write_tx_fifo)(struct qup_i2c_dev *qup);
282 	/* function to read data from rx fifo */
283 	void (*read_rx_fifo)(struct qup_i2c_dev *qup);
284 	/* function to write tags in tx fifo for i2c read transfer */
285 	void (*write_rx_tags)(struct qup_i2c_dev *qup);
286 };
287 
qup_i2c_interrupt(int irq,void * dev)288 static irqreturn_t qup_i2c_interrupt(int irq, void *dev)
289 {
290 	struct qup_i2c_dev *qup = dev;
291 	struct qup_i2c_block *blk = &qup->blk;
292 	u32 bus_err;
293 	u32 qup_err;
294 	u32 opflags;
295 
296 	bus_err = readl(qup->base + QUP_I2C_STATUS);
297 	qup_err = readl(qup->base + QUP_ERROR_FLAGS);
298 	opflags = readl(qup->base + QUP_OPERATIONAL);
299 
300 	if (!qup->msg) {
301 		/* Clear Error interrupt */
302 		writel(QUP_RESET_STATE, qup->base + QUP_STATE);
303 		return IRQ_HANDLED;
304 	}
305 
306 	bus_err &= I2C_STATUS_ERROR_MASK;
307 	qup_err &= QUP_STATUS_ERROR_FLAGS;
308 
309 	/* Clear the error bits in QUP_ERROR_FLAGS */
310 	if (qup_err)
311 		writel(qup_err, qup->base + QUP_ERROR_FLAGS);
312 
313 	/* Clear the error bits in QUP_I2C_STATUS */
314 	if (bus_err)
315 		writel(bus_err, qup->base + QUP_I2C_STATUS);
316 
317 	/*
318 	 * Check for BAM mode and returns if already error has come for current
319 	 * transfer. In Error case, sometimes, QUP generates more than one
320 	 * interrupt.
321 	 */
322 	if (qup->use_dma && (qup->qup_err || qup->bus_err))
323 		return IRQ_HANDLED;
324 
325 	/* Reset the QUP State in case of error */
326 	if (qup_err || bus_err) {
327 		/*
328 		 * Don’t reset the QUP state in case of BAM mode. The BAM
329 		 * flush operation needs to be scheduled in transfer function
330 		 * which will clear the remaining schedule descriptors in BAM
331 		 * HW FIFO and generates the BAM interrupt.
332 		 */
333 		if (!qup->use_dma)
334 			writel(QUP_RESET_STATE, qup->base + QUP_STATE);
335 		goto done;
336 	}
337 
338 	if (opflags & QUP_OUT_SVC_FLAG) {
339 		writel(QUP_OUT_SVC_FLAG, qup->base + QUP_OPERATIONAL);
340 
341 		if (opflags & OUT_BLOCK_WRITE_REQ) {
342 			blk->tx_fifo_free += qup->out_blk_sz;
343 			if (qup->msg->flags & I2C_M_RD)
344 				qup->write_rx_tags(qup);
345 			else
346 				qup->write_tx_fifo(qup);
347 		}
348 	}
349 
350 	if (opflags & QUP_IN_SVC_FLAG) {
351 		writel(QUP_IN_SVC_FLAG, qup->base + QUP_OPERATIONAL);
352 
353 		if (!blk->is_rx_blk_mode) {
354 			blk->fifo_available += qup->in_fifo_sz;
355 			qup->read_rx_fifo(qup);
356 		} else if (opflags & IN_BLOCK_READ_REQ) {
357 			blk->fifo_available += qup->in_blk_sz;
358 			qup->read_rx_fifo(qup);
359 		}
360 	}
361 
362 	if (qup->msg->flags & I2C_M_RD) {
363 		if (!blk->rx_bytes_read)
364 			return IRQ_HANDLED;
365 	} else {
366 		/*
367 		 * Ideally, QUP_MAX_OUTPUT_DONE_FLAG should be checked
368 		 * for FIFO mode also. But, QUP_MAX_OUTPUT_DONE_FLAG lags
369 		 * behind QUP_OUTPUT_SERVICE_FLAG sometimes. The only reason
370 		 * of interrupt for write message in FIFO mode is
371 		 * QUP_MAX_OUTPUT_DONE_FLAG condition.
372 		 */
373 		if (blk->is_tx_blk_mode && !(opflags & QUP_MX_OUTPUT_DONE))
374 			return IRQ_HANDLED;
375 	}
376 
377 done:
378 	qup->qup_err = qup_err;
379 	qup->bus_err = bus_err;
380 	complete(&qup->xfer);
381 	return IRQ_HANDLED;
382 }
383 
qup_i2c_poll_state_mask(struct qup_i2c_dev * qup,u32 req_state,u32 req_mask)384 static int qup_i2c_poll_state_mask(struct qup_i2c_dev *qup,
385 				   u32 req_state, u32 req_mask)
386 {
387 	int retries = 1;
388 	u32 state;
389 
390 	/*
391 	 * State transition takes 3 AHB clocks cycles + 3 I2C master clock
392 	 * cycles. So retry once after a 1uS delay.
393 	 */
394 	do {
395 		state = readl(qup->base + QUP_STATE);
396 
397 		if (state & QUP_STATE_VALID &&
398 		    (state & req_mask) == req_state)
399 			return 0;
400 
401 		udelay(1);
402 	} while (retries--);
403 
404 	return -ETIMEDOUT;
405 }
406 
qup_i2c_poll_state(struct qup_i2c_dev * qup,u32 req_state)407 static int qup_i2c_poll_state(struct qup_i2c_dev *qup, u32 req_state)
408 {
409 	return qup_i2c_poll_state_mask(qup, req_state, QUP_STATE_MASK);
410 }
411 
qup_i2c_flush(struct qup_i2c_dev * qup)412 static void qup_i2c_flush(struct qup_i2c_dev *qup)
413 {
414 	u32 val = readl(qup->base + QUP_STATE);
415 
416 	val |= QUP_I2C_FLUSH;
417 	writel(val, qup->base + QUP_STATE);
418 }
419 
qup_i2c_poll_state_valid(struct qup_i2c_dev * qup)420 static int qup_i2c_poll_state_valid(struct qup_i2c_dev *qup)
421 {
422 	return qup_i2c_poll_state_mask(qup, 0, 0);
423 }
424 
qup_i2c_poll_state_i2c_master(struct qup_i2c_dev * qup)425 static int qup_i2c_poll_state_i2c_master(struct qup_i2c_dev *qup)
426 {
427 	return qup_i2c_poll_state_mask(qup, QUP_I2C_MAST_GEN, QUP_I2C_MAST_GEN);
428 }
429 
qup_i2c_change_state(struct qup_i2c_dev * qup,u32 state)430 static int qup_i2c_change_state(struct qup_i2c_dev *qup, u32 state)
431 {
432 	if (qup_i2c_poll_state_valid(qup) != 0)
433 		return -EIO;
434 
435 	writel(state, qup->base + QUP_STATE);
436 
437 	if (qup_i2c_poll_state(qup, state) != 0)
438 		return -EIO;
439 	return 0;
440 }
441 
442 /* Check if I2C bus returns to IDLE state */
qup_i2c_bus_active(struct qup_i2c_dev * qup,int len)443 static int qup_i2c_bus_active(struct qup_i2c_dev *qup, int len)
444 {
445 	unsigned long timeout;
446 	u32 status;
447 	int ret = 0;
448 
449 	timeout = jiffies + len * 4;
450 	for (;;) {
451 		status = readl(qup->base + QUP_I2C_STATUS);
452 		if (!(status & I2C_STATUS_BUS_ACTIVE))
453 			break;
454 
455 		if (time_after(jiffies, timeout))
456 			ret = -ETIMEDOUT;
457 
458 		usleep_range(len, len * 2);
459 	}
460 
461 	return ret;
462 }
463 
qup_i2c_vote_bw(struct qup_i2c_dev * qup,u32 clk_freq)464 static int qup_i2c_vote_bw(struct qup_i2c_dev *qup, u32 clk_freq)
465 {
466 	u32 needed_peak_bw;
467 	int ret;
468 
469 	if (qup->cur_bw_clk_freq == clk_freq)
470 		return 0;
471 
472 	needed_peak_bw = Bps_to_icc(clk_freq * QUP_BUS_WIDTH);
473 	ret = icc_set_bw(qup->icc_path, 0, needed_peak_bw);
474 	if (ret)
475 		return ret;
476 
477 	qup->cur_bw_clk_freq = clk_freq;
478 	return 0;
479 }
480 
qup_i2c_write_tx_fifo_v1(struct qup_i2c_dev * qup)481 static void qup_i2c_write_tx_fifo_v1(struct qup_i2c_dev *qup)
482 {
483 	struct qup_i2c_block *blk = &qup->blk;
484 	struct i2c_msg *msg = qup->msg;
485 	u32 addr = i2c_8bit_addr_from_msg(msg);
486 	u32 qup_tag;
487 	int idx;
488 	u32 val;
489 
490 	if (qup->pos == 0) {
491 		val = QUP_TAG_START | addr;
492 		idx = 1;
493 		blk->tx_fifo_free--;
494 	} else {
495 		val = 0;
496 		idx = 0;
497 	}
498 
499 	while (blk->tx_fifo_free && qup->pos < msg->len) {
500 		if (qup->pos == msg->len - 1)
501 			qup_tag = QUP_TAG_STOP;
502 		else
503 			qup_tag = QUP_TAG_DATA;
504 
505 		if (idx & 1)
506 			val |= (qup_tag | msg->buf[qup->pos]) << QUP_MSW_SHIFT;
507 		else
508 			val = qup_tag | msg->buf[qup->pos];
509 
510 		/* Write out the pair and the last odd value */
511 		if (idx & 1 || qup->pos == msg->len - 1)
512 			writel(val, qup->base + QUP_OUT_FIFO_BASE);
513 
514 		qup->pos++;
515 		idx++;
516 		blk->tx_fifo_free--;
517 	}
518 }
519 
qup_i2c_set_blk_data(struct qup_i2c_dev * qup,struct i2c_msg * msg)520 static void qup_i2c_set_blk_data(struct qup_i2c_dev *qup,
521 				 struct i2c_msg *msg)
522 {
523 	qup->blk.pos = 0;
524 	qup->blk.data_len = msg->len;
525 	qup->blk.count = DIV_ROUND_UP(msg->len, qup->blk_xfer_limit);
526 }
527 
qup_i2c_get_data_len(struct qup_i2c_dev * qup)528 static int qup_i2c_get_data_len(struct qup_i2c_dev *qup)
529 {
530 	int data_len;
531 
532 	if (qup->blk.data_len > qup->blk_xfer_limit)
533 		data_len = qup->blk_xfer_limit;
534 	else
535 		data_len = qup->blk.data_len;
536 
537 	return data_len;
538 }
539 
qup_i2c_check_msg_len(struct i2c_msg * msg)540 static bool qup_i2c_check_msg_len(struct i2c_msg *msg)
541 {
542 	return ((msg->flags & I2C_M_RD) && (msg->flags & I2C_M_RECV_LEN));
543 }
544 
qup_i2c_set_tags_smb(u16 addr,u8 * tags,struct qup_i2c_dev * qup,struct i2c_msg * msg)545 static int qup_i2c_set_tags_smb(u16 addr, u8 *tags, struct qup_i2c_dev *qup,
546 			struct i2c_msg *msg)
547 {
548 	int len = 0;
549 
550 	if (qup->is_smbus_read) {
551 		tags[len++] = QUP_TAG_V2_DATARD_STOP;
552 		tags[len++] = qup_i2c_get_data_len(qup);
553 	} else {
554 		tags[len++] = QUP_TAG_V2_START;
555 		tags[len++] = addr & 0xff;
556 
557 		if (msg->flags & I2C_M_TEN)
558 			tags[len++] = addr >> 8;
559 
560 		tags[len++] = QUP_TAG_V2_DATARD;
561 		/* Read 1 byte indicating the length of the SMBus message */
562 		tags[len++] = 1;
563 	}
564 	return len;
565 }
566 
qup_i2c_set_tags(u8 * tags,struct qup_i2c_dev * qup,struct i2c_msg * msg)567 static int qup_i2c_set_tags(u8 *tags, struct qup_i2c_dev *qup,
568 			    struct i2c_msg *msg)
569 {
570 	u16 addr = i2c_8bit_addr_from_msg(msg);
571 	int len = 0;
572 	int data_len;
573 
574 	int last = (qup->blk.pos == (qup->blk.count - 1)) && (qup->is_last);
575 
576 	/* Handle tags for SMBus block read */
577 	if (qup_i2c_check_msg_len(msg))
578 		return qup_i2c_set_tags_smb(addr, tags, qup, msg);
579 
580 	if (qup->blk.pos == 0) {
581 		tags[len++] = QUP_TAG_V2_START;
582 		tags[len++] = addr & 0xff;
583 
584 		if (msg->flags & I2C_M_TEN)
585 			tags[len++] = addr >> 8;
586 	}
587 
588 	/* Send _STOP commands for the last block */
589 	if (last) {
590 		if (msg->flags & I2C_M_RD)
591 			tags[len++] = QUP_TAG_V2_DATARD_STOP;
592 		else
593 			tags[len++] = QUP_TAG_V2_DATAWR_STOP;
594 	} else {
595 		if (msg->flags & I2C_M_RD)
596 			tags[len++] = qup->blk.pos == (qup->blk.count - 1) ?
597 				      QUP_TAG_V2_DATARD_NACK :
598 				      QUP_TAG_V2_DATARD;
599 		else
600 			tags[len++] = QUP_TAG_V2_DATAWR;
601 	}
602 
603 	data_len = qup_i2c_get_data_len(qup);
604 
605 	/* 0 implies 256 bytes */
606 	if (data_len == QUP_READ_LIMIT)
607 		tags[len++] = 0;
608 	else
609 		tags[len++] = data_len;
610 
611 	return len;
612 }
613 
614 
qup_i2c_bam_cb(void * data)615 static void qup_i2c_bam_cb(void *data)
616 {
617 	struct qup_i2c_dev *qup = data;
618 
619 	complete(&qup->xfer);
620 }
621 
qup_sg_set_buf(struct scatterlist * sg,void * buf,unsigned int buflen,struct qup_i2c_dev * qup,int dir)622 static int qup_sg_set_buf(struct scatterlist *sg, void *buf,
623 			  unsigned int buflen, struct qup_i2c_dev *qup,
624 			  int dir)
625 {
626 	int ret;
627 
628 	sg_set_buf(sg, buf, buflen);
629 	ret = dma_map_sg(qup->dev, sg, 1, dir);
630 	if (!ret)
631 		return -EINVAL;
632 
633 	return 0;
634 }
635 
qup_i2c_rel_dma(struct qup_i2c_dev * qup)636 static void qup_i2c_rel_dma(struct qup_i2c_dev *qup)
637 {
638 	if (qup->btx.dma)
639 		dma_release_channel(qup->btx.dma);
640 	if (qup->brx.dma)
641 		dma_release_channel(qup->brx.dma);
642 	qup->btx.dma = NULL;
643 	qup->brx.dma = NULL;
644 }
645 
qup_i2c_req_dma(struct qup_i2c_dev * qup)646 static int qup_i2c_req_dma(struct qup_i2c_dev *qup)
647 {
648 	int err;
649 
650 	if (!qup->btx.dma) {
651 		qup->btx.dma = dma_request_chan(qup->dev, "tx");
652 		if (IS_ERR(qup->btx.dma)) {
653 			err = PTR_ERR(qup->btx.dma);
654 			qup->btx.dma = NULL;
655 			dev_err(qup->dev, "\n tx channel not available");
656 			return err;
657 		}
658 	}
659 
660 	if (!qup->brx.dma) {
661 		qup->brx.dma = dma_request_chan(qup->dev, "rx");
662 		if (IS_ERR(qup->brx.dma)) {
663 			dev_err(qup->dev, "\n rx channel not available");
664 			err = PTR_ERR(qup->brx.dma);
665 			qup->brx.dma = NULL;
666 			qup_i2c_rel_dma(qup);
667 			return err;
668 		}
669 	}
670 	return 0;
671 }
672 
qup_i2c_bam_make_desc(struct qup_i2c_dev * qup,struct i2c_msg * msg)673 static int qup_i2c_bam_make_desc(struct qup_i2c_dev *qup, struct i2c_msg *msg)
674 {
675 	int ret = 0, limit = QUP_READ_LIMIT;
676 	u32 len = 0, blocks, rem;
677 	u32 i = 0, tlen, tx_len = 0;
678 	u8 *tags;
679 
680 	qup->blk_xfer_limit = QUP_READ_LIMIT;
681 	qup_i2c_set_blk_data(qup, msg);
682 
683 	blocks = qup->blk.count;
684 	rem = msg->len - (blocks - 1) * limit;
685 
686 	if (msg->flags & I2C_M_RD) {
687 		while (qup->blk.pos < blocks) {
688 			tlen = (i == (blocks - 1)) ? rem : limit;
689 			tags = &qup->start_tag.start[qup->tag_buf_pos + len];
690 			len += qup_i2c_set_tags(tags, qup, msg);
691 			qup->blk.data_len -= tlen;
692 
693 			/* scratch buf to read the start and len tags */
694 			ret = qup_sg_set_buf(&qup->brx.sg[qup->brx.sg_cnt++],
695 					     &qup->brx.tag.start[0],
696 					     2, qup, DMA_FROM_DEVICE);
697 
698 			if (ret)
699 				return ret;
700 
701 			ret = qup_sg_set_buf(&qup->brx.sg[qup->brx.sg_cnt++],
702 					     &msg->buf[limit * i],
703 					     tlen, qup,
704 					     DMA_FROM_DEVICE);
705 			if (ret)
706 				return ret;
707 
708 			i++;
709 			qup->blk.pos = i;
710 		}
711 		ret = qup_sg_set_buf(&qup->btx.sg[qup->btx.sg_cnt++],
712 				     &qup->start_tag.start[qup->tag_buf_pos],
713 				     len, qup, DMA_TO_DEVICE);
714 		if (ret)
715 			return ret;
716 
717 		qup->tag_buf_pos += len;
718 	} else {
719 		while (qup->blk.pos < blocks) {
720 			tlen = (i == (blocks - 1)) ? rem : limit;
721 			tags = &qup->start_tag.start[qup->tag_buf_pos + tx_len];
722 			len = qup_i2c_set_tags(tags, qup, msg);
723 			qup->blk.data_len -= tlen;
724 
725 			ret = qup_sg_set_buf(&qup->btx.sg[qup->btx.sg_cnt++],
726 					     tags, len,
727 					     qup, DMA_TO_DEVICE);
728 			if (ret)
729 				return ret;
730 
731 			tx_len += len;
732 			ret = qup_sg_set_buf(&qup->btx.sg[qup->btx.sg_cnt++],
733 					     &msg->buf[limit * i],
734 					     tlen, qup, DMA_TO_DEVICE);
735 			if (ret)
736 				return ret;
737 			i++;
738 			qup->blk.pos = i;
739 		}
740 
741 		qup->tag_buf_pos += tx_len;
742 	}
743 
744 	return 0;
745 }
746 
qup_i2c_bam_schedule_desc(struct qup_i2c_dev * qup)747 static int qup_i2c_bam_schedule_desc(struct qup_i2c_dev *qup)
748 {
749 	struct dma_async_tx_descriptor *txd, *rxd = NULL;
750 	int ret = 0;
751 	dma_cookie_t cookie_rx, cookie_tx;
752 	u32 len = 0;
753 	u32 tx_cnt = qup->btx.sg_cnt, rx_cnt = qup->brx.sg_cnt;
754 
755 	/* schedule the EOT and FLUSH I2C tags */
756 	len = 1;
757 	if (rx_cnt) {
758 		qup->btx.tag.start[0] = QUP_BAM_INPUT_EOT;
759 		len++;
760 
761 		/* scratch buf to read the BAM EOT FLUSH tags */
762 		ret = qup_sg_set_buf(&qup->brx.sg[rx_cnt++],
763 				     &qup->brx.tag.start[0],
764 				     1, qup, DMA_FROM_DEVICE);
765 		if (ret)
766 			return ret;
767 	}
768 
769 	qup->btx.tag.start[len - 1] = QUP_BAM_FLUSH_STOP;
770 	ret = qup_sg_set_buf(&qup->btx.sg[tx_cnt++], &qup->btx.tag.start[0],
771 			     len, qup, DMA_TO_DEVICE);
772 	if (ret)
773 		return ret;
774 
775 	txd = dmaengine_prep_slave_sg(qup->btx.dma, qup->btx.sg, tx_cnt,
776 				      DMA_MEM_TO_DEV,
777 				      DMA_PREP_INTERRUPT | DMA_PREP_FENCE);
778 	if (!txd) {
779 		dev_err(qup->dev, "failed to get tx desc\n");
780 		ret = -EINVAL;
781 		goto desc_err;
782 	}
783 
784 	if (!rx_cnt) {
785 		txd->callback = qup_i2c_bam_cb;
786 		txd->callback_param = qup;
787 	}
788 
789 	cookie_tx = dmaengine_submit(txd);
790 	if (dma_submit_error(cookie_tx)) {
791 		ret = -EINVAL;
792 		goto desc_err;
793 	}
794 
795 	dma_async_issue_pending(qup->btx.dma);
796 
797 	if (rx_cnt) {
798 		rxd = dmaengine_prep_slave_sg(qup->brx.dma, qup->brx.sg,
799 					      rx_cnt, DMA_DEV_TO_MEM,
800 					      DMA_PREP_INTERRUPT);
801 		if (!rxd) {
802 			dev_err(qup->dev, "failed to get rx desc\n");
803 			ret = -EINVAL;
804 
805 			/* abort TX descriptors */
806 			dmaengine_terminate_sync(qup->btx.dma);
807 			goto desc_err;
808 		}
809 
810 		rxd->callback = qup_i2c_bam_cb;
811 		rxd->callback_param = qup;
812 		cookie_rx = dmaengine_submit(rxd);
813 		if (dma_submit_error(cookie_rx)) {
814 			ret = -EINVAL;
815 			goto desc_err;
816 		}
817 
818 		dma_async_issue_pending(qup->brx.dma);
819 	}
820 
821 	if (!wait_for_completion_timeout(&qup->xfer, qup->xfer_timeout))
822 		ret = -ETIMEDOUT;
823 
824 	if (ret || qup->bus_err || qup->qup_err) {
825 		reinit_completion(&qup->xfer);
826 
827 		ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
828 		if (ret) {
829 			dev_err(qup->dev, "change to run state timed out");
830 			goto desc_err;
831 		}
832 
833 		qup_i2c_flush(qup);
834 
835 		/* wait for remaining interrupts to occur */
836 		if (!wait_for_completion_timeout(&qup->xfer, HZ))
837 			dev_err(qup->dev, "flush timed out\n");
838 
839 		ret =  (qup->bus_err & QUP_I2C_NACK_FLAG) ? -ENXIO : -EIO;
840 	}
841 
842 desc_err:
843 	dma_unmap_sg(qup->dev, qup->btx.sg, tx_cnt, DMA_TO_DEVICE);
844 
845 	if (rx_cnt)
846 		dma_unmap_sg(qup->dev, qup->brx.sg, rx_cnt,
847 			     DMA_FROM_DEVICE);
848 
849 	return ret;
850 }
851 
qup_i2c_bam_clear_tag_buffers(struct qup_i2c_dev * qup)852 static void qup_i2c_bam_clear_tag_buffers(struct qup_i2c_dev *qup)
853 {
854 	qup->btx.sg_cnt = 0;
855 	qup->brx.sg_cnt = 0;
856 	qup->tag_buf_pos = 0;
857 }
858 
qup_i2c_bam_xfer(struct i2c_adapter * adap,struct i2c_msg * msg,int num)859 static int qup_i2c_bam_xfer(struct i2c_adapter *adap, struct i2c_msg *msg,
860 			    int num)
861 {
862 	struct qup_i2c_dev *qup = i2c_get_adapdata(adap);
863 	int ret = 0;
864 	int idx = 0;
865 
866 	ret = qup_i2c_vote_bw(qup, qup->src_clk_freq);
867 	if (ret)
868 		return ret;
869 
870 	enable_irq(qup->irq);
871 	ret = qup_i2c_req_dma(qup);
872 
873 	if (ret)
874 		goto out;
875 
876 	writel(0, qup->base + QUP_MX_INPUT_CNT);
877 	writel(0, qup->base + QUP_MX_OUTPUT_CNT);
878 
879 	/* set BAM mode */
880 	writel(QUP_REPACK_EN | QUP_BAM_MODE, qup->base + QUP_IO_MODE);
881 
882 	/* mask fifo irqs */
883 	writel((0x3 << 8), qup->base + QUP_OPERATIONAL_MASK);
884 
885 	/* set RUN STATE */
886 	ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
887 	if (ret)
888 		goto out;
889 
890 	writel(qup->clk_ctl, qup->base + QUP_I2C_CLK_CTL);
891 	qup_i2c_bam_clear_tag_buffers(qup);
892 
893 	for (idx = 0; idx < num; idx++) {
894 		qup->msg = msg + idx;
895 		qup->is_last = idx == (num - 1);
896 
897 		ret = qup_i2c_bam_make_desc(qup, qup->msg);
898 		if (ret)
899 			break;
900 
901 		/*
902 		 * Make DMA descriptor and schedule the BAM transfer if its
903 		 * already crossed the maximum length. Since the memory for all
904 		 * tags buffers have been taken for 2 maximum possible
905 		 * transfers length so it will never cross the buffer actual
906 		 * length.
907 		 */
908 		if (qup->btx.sg_cnt > qup->max_xfer_sg_len ||
909 		    qup->brx.sg_cnt > qup->max_xfer_sg_len ||
910 		    qup->is_last) {
911 			ret = qup_i2c_bam_schedule_desc(qup);
912 			if (ret)
913 				break;
914 
915 			qup_i2c_bam_clear_tag_buffers(qup);
916 		}
917 	}
918 
919 out:
920 	disable_irq(qup->irq);
921 
922 	qup->msg = NULL;
923 	return ret;
924 }
925 
qup_i2c_wait_for_complete(struct qup_i2c_dev * qup,struct i2c_msg * msg)926 static int qup_i2c_wait_for_complete(struct qup_i2c_dev *qup,
927 				     struct i2c_msg *msg)
928 {
929 	unsigned long left;
930 	int ret = 0;
931 
932 	left = wait_for_completion_timeout(&qup->xfer, qup->xfer_timeout);
933 	if (!left) {
934 		writel(1, qup->base + QUP_SW_RESET);
935 		ret = -ETIMEDOUT;
936 	}
937 
938 	if (qup->bus_err || qup->qup_err)
939 		ret =  (qup->bus_err & QUP_I2C_NACK_FLAG) ? -ENXIO : -EIO;
940 
941 	return ret;
942 }
943 
qup_i2c_read_rx_fifo_v1(struct qup_i2c_dev * qup)944 static void qup_i2c_read_rx_fifo_v1(struct qup_i2c_dev *qup)
945 {
946 	struct qup_i2c_block *blk = &qup->blk;
947 	struct i2c_msg *msg = qup->msg;
948 	u32 val = 0;
949 	int idx = 0;
950 
951 	while (blk->fifo_available && qup->pos < msg->len) {
952 		if ((idx & 1) == 0) {
953 			/* Reading 2 words at time */
954 			val = readl(qup->base + QUP_IN_FIFO_BASE);
955 			msg->buf[qup->pos++] = val & 0xFF;
956 		} else {
957 			msg->buf[qup->pos++] = val >> QUP_MSW_SHIFT;
958 		}
959 		idx++;
960 		blk->fifo_available--;
961 	}
962 
963 	if (qup->pos == msg->len)
964 		blk->rx_bytes_read = true;
965 }
966 
qup_i2c_write_rx_tags_v1(struct qup_i2c_dev * qup)967 static void qup_i2c_write_rx_tags_v1(struct qup_i2c_dev *qup)
968 {
969 	struct i2c_msg *msg = qup->msg;
970 	u32 addr, len, val;
971 
972 	addr = i2c_8bit_addr_from_msg(msg);
973 
974 	/* 0 is used to specify a length 256 (QUP_READ_LIMIT) */
975 	len = (msg->len == QUP_READ_LIMIT) ? 0 : msg->len;
976 
977 	val = ((QUP_TAG_REC | len) << QUP_MSW_SHIFT) | QUP_TAG_START | addr;
978 	writel(val, qup->base + QUP_OUT_FIFO_BASE);
979 }
980 
qup_i2c_conf_v1(struct qup_i2c_dev * qup)981 static void qup_i2c_conf_v1(struct qup_i2c_dev *qup)
982 {
983 	struct qup_i2c_block *blk = &qup->blk;
984 	u32 qup_config = I2C_MINI_CORE | I2C_N_VAL;
985 	u32 io_mode = QUP_REPACK_EN;
986 
987 	blk->is_tx_blk_mode = blk->total_tx_len > qup->out_fifo_sz;
988 	blk->is_rx_blk_mode = blk->total_rx_len > qup->in_fifo_sz;
989 
990 	if (blk->is_tx_blk_mode) {
991 		io_mode |= QUP_OUTPUT_BLK_MODE;
992 		writel(0, qup->base + QUP_MX_WRITE_CNT);
993 		writel(blk->total_tx_len, qup->base + QUP_MX_OUTPUT_CNT);
994 	} else {
995 		writel(0, qup->base + QUP_MX_OUTPUT_CNT);
996 		writel(blk->total_tx_len, qup->base + QUP_MX_WRITE_CNT);
997 	}
998 
999 	if (blk->total_rx_len) {
1000 		if (blk->is_rx_blk_mode) {
1001 			io_mode |= QUP_INPUT_BLK_MODE;
1002 			writel(0, qup->base + QUP_MX_READ_CNT);
1003 			writel(blk->total_rx_len, qup->base + QUP_MX_INPUT_CNT);
1004 		} else {
1005 			writel(0, qup->base + QUP_MX_INPUT_CNT);
1006 			writel(blk->total_rx_len, qup->base + QUP_MX_READ_CNT);
1007 		}
1008 	} else {
1009 		qup_config |= QUP_NO_INPUT;
1010 	}
1011 
1012 	writel(qup_config, qup->base + QUP_CONFIG);
1013 	writel(io_mode, qup->base + QUP_IO_MODE);
1014 }
1015 
qup_i2c_clear_blk_v1(struct qup_i2c_block * blk)1016 static void qup_i2c_clear_blk_v1(struct qup_i2c_block *blk)
1017 {
1018 	blk->tx_fifo_free = 0;
1019 	blk->fifo_available = 0;
1020 	blk->rx_bytes_read = false;
1021 }
1022 
qup_i2c_conf_xfer_v1(struct qup_i2c_dev * qup,bool is_rx)1023 static int qup_i2c_conf_xfer_v1(struct qup_i2c_dev *qup, bool is_rx)
1024 {
1025 	struct qup_i2c_block *blk = &qup->blk;
1026 	int ret;
1027 
1028 	qup_i2c_clear_blk_v1(blk);
1029 	qup_i2c_conf_v1(qup);
1030 	ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
1031 	if (ret)
1032 		return ret;
1033 
1034 	writel(qup->clk_ctl, qup->base + QUP_I2C_CLK_CTL);
1035 
1036 	ret = qup_i2c_change_state(qup, QUP_PAUSE_STATE);
1037 	if (ret)
1038 		return ret;
1039 
1040 	reinit_completion(&qup->xfer);
1041 	enable_irq(qup->irq);
1042 	if (!blk->is_tx_blk_mode) {
1043 		blk->tx_fifo_free = qup->out_fifo_sz;
1044 
1045 		if (is_rx)
1046 			qup_i2c_write_rx_tags_v1(qup);
1047 		else
1048 			qup_i2c_write_tx_fifo_v1(qup);
1049 	}
1050 
1051 	ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
1052 	if (ret)
1053 		goto err;
1054 
1055 	ret = qup_i2c_wait_for_complete(qup, qup->msg);
1056 	if (ret)
1057 		goto err;
1058 
1059 	ret = qup_i2c_bus_active(qup, ONE_BYTE);
1060 
1061 err:
1062 	disable_irq(qup->irq);
1063 	return ret;
1064 }
1065 
qup_i2c_write_one(struct qup_i2c_dev * qup)1066 static int qup_i2c_write_one(struct qup_i2c_dev *qup)
1067 {
1068 	struct i2c_msg *msg = qup->msg;
1069 	struct qup_i2c_block *blk = &qup->blk;
1070 
1071 	qup->pos = 0;
1072 	blk->total_tx_len = msg->len + 1;
1073 	blk->total_rx_len = 0;
1074 
1075 	return qup_i2c_conf_xfer_v1(qup, false);
1076 }
1077 
qup_i2c_read_one(struct qup_i2c_dev * qup)1078 static int qup_i2c_read_one(struct qup_i2c_dev *qup)
1079 {
1080 	struct qup_i2c_block *blk = &qup->blk;
1081 
1082 	qup->pos = 0;
1083 	blk->total_tx_len = 2;
1084 	blk->total_rx_len = qup->msg->len;
1085 
1086 	return qup_i2c_conf_xfer_v1(qup, true);
1087 }
1088 
qup_i2c_xfer(struct i2c_adapter * adap,struct i2c_msg msgs[],int num)1089 static int qup_i2c_xfer(struct i2c_adapter *adap,
1090 			struct i2c_msg msgs[],
1091 			int num)
1092 {
1093 	struct qup_i2c_dev *qup = i2c_get_adapdata(adap);
1094 	int ret, idx;
1095 
1096 	ret = pm_runtime_get_sync(qup->dev);
1097 	if (ret < 0)
1098 		goto out;
1099 
1100 	qup->bus_err = 0;
1101 	qup->qup_err = 0;
1102 
1103 	writel(1, qup->base + QUP_SW_RESET);
1104 	ret = qup_i2c_poll_state(qup, QUP_RESET_STATE);
1105 	if (ret)
1106 		goto out;
1107 
1108 	/* Configure QUP as I2C mini core */
1109 	writel(I2C_MINI_CORE | I2C_N_VAL, qup->base + QUP_CONFIG);
1110 
1111 	for (idx = 0; idx < num; idx++) {
1112 		if (qup_i2c_poll_state_i2c_master(qup)) {
1113 			ret = -EIO;
1114 			goto out;
1115 		}
1116 
1117 		if (qup_i2c_check_msg_len(&msgs[idx])) {
1118 			ret = -EINVAL;
1119 			goto out;
1120 		}
1121 
1122 		qup->msg = &msgs[idx];
1123 		if (msgs[idx].flags & I2C_M_RD)
1124 			ret = qup_i2c_read_one(qup);
1125 		else
1126 			ret = qup_i2c_write_one(qup);
1127 
1128 		if (ret)
1129 			break;
1130 
1131 		ret = qup_i2c_change_state(qup, QUP_RESET_STATE);
1132 		if (ret)
1133 			break;
1134 	}
1135 
1136 	if (ret == 0)
1137 		ret = num;
1138 out:
1139 
1140 	pm_runtime_mark_last_busy(qup->dev);
1141 	pm_runtime_put_autosuspend(qup->dev);
1142 
1143 	return ret;
1144 }
1145 
1146 /*
1147  * Configure registers related with reconfiguration during run and call it
1148  * before each i2c sub transfer.
1149  */
qup_i2c_conf_count_v2(struct qup_i2c_dev * qup)1150 static void qup_i2c_conf_count_v2(struct qup_i2c_dev *qup)
1151 {
1152 	struct qup_i2c_block *blk = &qup->blk;
1153 	u32 qup_config = I2C_MINI_CORE | I2C_N_VAL_V2;
1154 
1155 	if (blk->is_tx_blk_mode)
1156 		writel(qup->config_run | blk->total_tx_len,
1157 		       qup->base + QUP_MX_OUTPUT_CNT);
1158 	else
1159 		writel(qup->config_run | blk->total_tx_len,
1160 		       qup->base + QUP_MX_WRITE_CNT);
1161 
1162 	if (blk->total_rx_len) {
1163 		if (blk->is_rx_blk_mode)
1164 			writel(qup->config_run | blk->total_rx_len,
1165 			       qup->base + QUP_MX_INPUT_CNT);
1166 		else
1167 			writel(qup->config_run | blk->total_rx_len,
1168 			       qup->base + QUP_MX_READ_CNT);
1169 	} else {
1170 		qup_config |= QUP_NO_INPUT;
1171 	}
1172 
1173 	writel(qup_config, qup->base + QUP_CONFIG);
1174 }
1175 
1176 /*
1177  * Configure registers related with transfer mode (FIFO/Block)
1178  * before starting of i2c transfer. It will be called only once in
1179  * QUP RESET state.
1180  */
qup_i2c_conf_mode_v2(struct qup_i2c_dev * qup)1181 static void qup_i2c_conf_mode_v2(struct qup_i2c_dev *qup)
1182 {
1183 	struct qup_i2c_block *blk = &qup->blk;
1184 	u32 io_mode = QUP_REPACK_EN;
1185 
1186 	if (blk->is_tx_blk_mode) {
1187 		io_mode |= QUP_OUTPUT_BLK_MODE;
1188 		writel(0, qup->base + QUP_MX_WRITE_CNT);
1189 	} else {
1190 		writel(0, qup->base + QUP_MX_OUTPUT_CNT);
1191 	}
1192 
1193 	if (blk->is_rx_blk_mode) {
1194 		io_mode |= QUP_INPUT_BLK_MODE;
1195 		writel(0, qup->base + QUP_MX_READ_CNT);
1196 	} else {
1197 		writel(0, qup->base + QUP_MX_INPUT_CNT);
1198 	}
1199 
1200 	writel(io_mode, qup->base + QUP_IO_MODE);
1201 }
1202 
1203 /* Clear required variables before starting of any QUP v2 sub transfer. */
qup_i2c_clear_blk_v2(struct qup_i2c_block * blk)1204 static void qup_i2c_clear_blk_v2(struct qup_i2c_block *blk)
1205 {
1206 	blk->send_last_word = false;
1207 	blk->tx_tags_sent = false;
1208 	blk->tx_fifo_data = 0;
1209 	blk->tx_fifo_data_pos = 0;
1210 	blk->tx_fifo_free = 0;
1211 
1212 	blk->rx_tags_fetched = false;
1213 	blk->rx_bytes_read = false;
1214 	blk->rx_fifo_data = 0;
1215 	blk->rx_fifo_data_pos = 0;
1216 	blk->fifo_available = 0;
1217 }
1218 
1219 /* Receive data from RX FIFO for read message in QUP v2 i2c transfer. */
qup_i2c_recv_data(struct qup_i2c_dev * qup)1220 static void qup_i2c_recv_data(struct qup_i2c_dev *qup)
1221 {
1222 	struct qup_i2c_block *blk = &qup->blk;
1223 	int j;
1224 
1225 	for (j = blk->rx_fifo_data_pos;
1226 	     blk->cur_blk_len && blk->fifo_available;
1227 	     blk->cur_blk_len--, blk->fifo_available--) {
1228 		if (j == 0)
1229 			blk->rx_fifo_data = readl(qup->base + QUP_IN_FIFO_BASE);
1230 
1231 		*(blk->cur_data++) = blk->rx_fifo_data;
1232 		blk->rx_fifo_data >>= 8;
1233 
1234 		if (j == 3)
1235 			j = 0;
1236 		else
1237 			j++;
1238 	}
1239 
1240 	blk->rx_fifo_data_pos = j;
1241 }
1242 
1243 /* Receive tags for read message in QUP v2 i2c transfer. */
qup_i2c_recv_tags(struct qup_i2c_dev * qup)1244 static void qup_i2c_recv_tags(struct qup_i2c_dev *qup)
1245 {
1246 	struct qup_i2c_block *blk = &qup->blk;
1247 
1248 	blk->rx_fifo_data = readl(qup->base + QUP_IN_FIFO_BASE);
1249 	blk->rx_fifo_data >>= blk->rx_tag_len  * 8;
1250 	blk->rx_fifo_data_pos = blk->rx_tag_len;
1251 	blk->fifo_available -= blk->rx_tag_len;
1252 }
1253 
1254 /*
1255  * Read the data and tags from RX FIFO. Since in read case, the tags will be
1256  * preceded by received data bytes so
1257  * 1. Check if rx_tags_fetched is false i.e. the start of QUP block so receive
1258  *    all tag bytes and discard that.
1259  * 2. Read the data from RX FIFO. When all the data bytes have been read then
1260  *    set rx_bytes_read to true.
1261  */
qup_i2c_read_rx_fifo_v2(struct qup_i2c_dev * qup)1262 static void qup_i2c_read_rx_fifo_v2(struct qup_i2c_dev *qup)
1263 {
1264 	struct qup_i2c_block *blk = &qup->blk;
1265 
1266 	if (!blk->rx_tags_fetched) {
1267 		qup_i2c_recv_tags(qup);
1268 		blk->rx_tags_fetched = true;
1269 	}
1270 
1271 	qup_i2c_recv_data(qup);
1272 	if (!blk->cur_blk_len)
1273 		blk->rx_bytes_read = true;
1274 }
1275 
1276 /*
1277  * Write bytes in TX FIFO for write message in QUP v2 i2c transfer. QUP TX FIFO
1278  * write works on word basis (4 bytes). Append new data byte write for TX FIFO
1279  * in tx_fifo_data and write to TX FIFO when all the 4 bytes are present.
1280  */
1281 static void
qup_i2c_write_blk_data(struct qup_i2c_dev * qup,u8 ** data,unsigned int * len)1282 qup_i2c_write_blk_data(struct qup_i2c_dev *qup, u8 **data, unsigned int *len)
1283 {
1284 	struct qup_i2c_block *blk = &qup->blk;
1285 	unsigned int j;
1286 
1287 	for (j = blk->tx_fifo_data_pos; *len && blk->tx_fifo_free;
1288 	     (*len)--, blk->tx_fifo_free--) {
1289 		blk->tx_fifo_data |= *(*data)++ << (j * 8);
1290 		if (j == 3) {
1291 			writel(blk->tx_fifo_data,
1292 			       qup->base + QUP_OUT_FIFO_BASE);
1293 			blk->tx_fifo_data = 0x0;
1294 			j = 0;
1295 		} else {
1296 			j++;
1297 		}
1298 	}
1299 
1300 	blk->tx_fifo_data_pos = j;
1301 }
1302 
1303 /* Transfer tags for read message in QUP v2 i2c transfer. */
qup_i2c_write_rx_tags_v2(struct qup_i2c_dev * qup)1304 static void qup_i2c_write_rx_tags_v2(struct qup_i2c_dev *qup)
1305 {
1306 	struct qup_i2c_block *blk = &qup->blk;
1307 
1308 	qup_i2c_write_blk_data(qup, &blk->cur_tx_tags, &blk->tx_tag_len);
1309 	if (blk->tx_fifo_data_pos)
1310 		writel(blk->tx_fifo_data, qup->base + QUP_OUT_FIFO_BASE);
1311 }
1312 
1313 /*
1314  * Write the data and tags in TX FIFO. Since in write case, both tags and data
1315  * need to be written and QUP write tags can have maximum 256 data length, so
1316  *
1317  * 1. Check if tx_tags_sent is false i.e. the start of QUP block so write the
1318  *    tags to TX FIFO and set tx_tags_sent to true.
1319  * 2. Check if send_last_word is true. It will be set when last few data bytes
1320  *    (less than 4 bytes) are remaining to be written in FIFO because of no FIFO
1321  *    space. All this data bytes are available in tx_fifo_data so write this
1322  *    in FIFO.
1323  * 3. Write the data to TX FIFO and check for cur_blk_len. If it is non zero
1324  *    then more data is pending otherwise following 3 cases can be possible
1325  *    a. if tx_fifo_data_pos is zero i.e. all the data bytes in this block
1326  *       have been written in TX FIFO so nothing else is required.
1327  *    b. tx_fifo_free is non zero i.e tx FIFO is free so copy the remaining data
1328  *       from tx_fifo_data to tx FIFO. Since, qup_i2c_write_blk_data do write
1329  *	 in 4 bytes and FIFO space is in multiple of 4 bytes so tx_fifo_free
1330  *       will be always greater than or equal to 4 bytes.
1331  *    c. tx_fifo_free is zero. In this case, last few bytes (less than 4
1332  *       bytes) are copied to tx_fifo_data but couldn't be sent because of
1333  *       FIFO full so make send_last_word true.
1334  */
qup_i2c_write_tx_fifo_v2(struct qup_i2c_dev * qup)1335 static void qup_i2c_write_tx_fifo_v2(struct qup_i2c_dev *qup)
1336 {
1337 	struct qup_i2c_block *blk = &qup->blk;
1338 
1339 	if (!blk->tx_tags_sent) {
1340 		qup_i2c_write_blk_data(qup, &blk->cur_tx_tags,
1341 				       &blk->tx_tag_len);
1342 		blk->tx_tags_sent = true;
1343 	}
1344 
1345 	if (blk->send_last_word)
1346 		goto send_last_word;
1347 
1348 	qup_i2c_write_blk_data(qup, &blk->cur_data, &blk->cur_blk_len);
1349 	if (!blk->cur_blk_len) {
1350 		if (!blk->tx_fifo_data_pos)
1351 			return;
1352 
1353 		if (blk->tx_fifo_free)
1354 			goto send_last_word;
1355 
1356 		blk->send_last_word = true;
1357 	}
1358 
1359 	return;
1360 
1361 send_last_word:
1362 	writel(blk->tx_fifo_data, qup->base + QUP_OUT_FIFO_BASE);
1363 }
1364 
1365 /*
1366  * Main transfer function which read or write i2c data.
1367  * The QUP v2 supports reconfiguration during run in which multiple i2c sub
1368  * transfers can be scheduled.
1369  */
1370 static int
qup_i2c_conf_xfer_v2(struct qup_i2c_dev * qup,bool is_rx,bool is_first,bool change_pause_state)1371 qup_i2c_conf_xfer_v2(struct qup_i2c_dev *qup, bool is_rx, bool is_first,
1372 		     bool change_pause_state)
1373 {
1374 	struct qup_i2c_block *blk = &qup->blk;
1375 	struct i2c_msg *msg = qup->msg;
1376 	int ret;
1377 
1378 	/*
1379 	 * Check if its SMBus Block read for which the top level read will be
1380 	 * done into 2 QUP reads. One with message length 1 while other one is
1381 	 * with actual length.
1382 	 */
1383 	if (qup_i2c_check_msg_len(msg)) {
1384 		if (qup->is_smbus_read) {
1385 			/*
1386 			 * If the message length is already read in
1387 			 * the first byte of the buffer, account for
1388 			 * that by setting the offset
1389 			 */
1390 			blk->cur_data += 1;
1391 			is_first = false;
1392 		} else {
1393 			change_pause_state = false;
1394 		}
1395 	}
1396 
1397 	qup->config_run = is_first ? 0 : QUP_I2C_MX_CONFIG_DURING_RUN;
1398 
1399 	qup_i2c_clear_blk_v2(blk);
1400 	qup_i2c_conf_count_v2(qup);
1401 
1402 	/* If it is first sub transfer, then configure i2c bus clocks */
1403 	if (is_first) {
1404 		ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
1405 		if (ret)
1406 			return ret;
1407 
1408 		writel(qup->clk_ctl, qup->base + QUP_I2C_CLK_CTL);
1409 
1410 		ret = qup_i2c_change_state(qup, QUP_PAUSE_STATE);
1411 		if (ret)
1412 			return ret;
1413 	}
1414 
1415 	reinit_completion(&qup->xfer);
1416 	enable_irq(qup->irq);
1417 	/*
1418 	 * In FIFO mode, tx FIFO can be written directly while in block mode the
1419 	 * it will be written after getting OUT_BLOCK_WRITE_REQ interrupt
1420 	 */
1421 	if (!blk->is_tx_blk_mode) {
1422 		blk->tx_fifo_free = qup->out_fifo_sz;
1423 
1424 		if (is_rx)
1425 			qup_i2c_write_rx_tags_v2(qup);
1426 		else
1427 			qup_i2c_write_tx_fifo_v2(qup);
1428 	}
1429 
1430 	ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
1431 	if (ret)
1432 		goto err;
1433 
1434 	ret = qup_i2c_wait_for_complete(qup, msg);
1435 	if (ret)
1436 		goto err;
1437 
1438 	/* Move to pause state for all the transfers, except last one */
1439 	if (change_pause_state) {
1440 		ret = qup_i2c_change_state(qup, QUP_PAUSE_STATE);
1441 		if (ret)
1442 			goto err;
1443 	}
1444 
1445 err:
1446 	disable_irq(qup->irq);
1447 	return ret;
1448 }
1449 
1450 /*
1451  * Transfer one read/write message in i2c transfer. It splits the message into
1452  * multiple of blk_xfer_limit data length blocks and schedule each
1453  * QUP block individually.
1454  */
qup_i2c_xfer_v2_msg(struct qup_i2c_dev * qup,int msg_id,bool is_rx)1455 static int qup_i2c_xfer_v2_msg(struct qup_i2c_dev *qup, int msg_id, bool is_rx)
1456 {
1457 	int ret = 0;
1458 	unsigned int data_len, i;
1459 	struct i2c_msg *msg = qup->msg;
1460 	struct qup_i2c_block *blk = &qup->blk;
1461 	u8 *msg_buf = msg->buf;
1462 
1463 	qup->blk_xfer_limit = is_rx ? RECV_MAX_DATA_LEN : QUP_READ_LIMIT;
1464 	qup_i2c_set_blk_data(qup, msg);
1465 
1466 	for (i = 0; i < blk->count; i++) {
1467 		data_len =  qup_i2c_get_data_len(qup);
1468 		blk->pos = i;
1469 		blk->cur_tx_tags = blk->tags;
1470 		blk->cur_blk_len = data_len;
1471 		blk->tx_tag_len =
1472 			qup_i2c_set_tags(blk->cur_tx_tags, qup, qup->msg);
1473 
1474 		blk->cur_data = msg_buf;
1475 
1476 		if (is_rx) {
1477 			blk->total_tx_len = blk->tx_tag_len;
1478 			blk->rx_tag_len = 2;
1479 			blk->total_rx_len = blk->rx_tag_len + data_len;
1480 		} else {
1481 			blk->total_tx_len = blk->tx_tag_len + data_len;
1482 			blk->total_rx_len = 0;
1483 		}
1484 
1485 		ret = qup_i2c_conf_xfer_v2(qup, is_rx, !msg_id && !i,
1486 					   !qup->is_last || i < blk->count - 1);
1487 		if (ret)
1488 			return ret;
1489 
1490 		/* Handle SMBus block read length */
1491 		if (qup_i2c_check_msg_len(msg) && msg->len == 1 &&
1492 		    !qup->is_smbus_read) {
1493 			if (msg->buf[0] > I2C_SMBUS_BLOCK_MAX)
1494 				return -EPROTO;
1495 
1496 			msg->len = msg->buf[0];
1497 			qup->is_smbus_read = true;
1498 			ret = qup_i2c_xfer_v2_msg(qup, msg_id, true);
1499 			qup->is_smbus_read = false;
1500 			if (ret)
1501 				return ret;
1502 
1503 			msg->len += 1;
1504 		}
1505 
1506 		msg_buf += data_len;
1507 		blk->data_len -= qup->blk_xfer_limit;
1508 	}
1509 
1510 	return ret;
1511 }
1512 
1513 /*
1514  * QUP v2 supports 3 modes
1515  * Programmed IO using FIFO mode : Less than FIFO size
1516  * Programmed IO using Block mode : Greater than FIFO size
1517  * DMA using BAM : Appropriate for any transaction size but the address should
1518  *		   be DMA applicable
1519  *
1520  * This function determines the mode which will be used for this transfer. An
1521  * i2c transfer contains multiple message. Following are the rules to determine
1522  * the mode used.
1523  * 1. Determine complete length, maximum tx and rx length for complete transfer.
1524  * 2. If complete transfer length is greater than fifo size then use the DMA
1525  *    mode.
1526  * 3. In FIFO or block mode, tx and rx can operate in different mode so check
1527  *    for maximum tx and rx length to determine mode.
1528  */
1529 static int
qup_i2c_determine_mode_v2(struct qup_i2c_dev * qup,struct i2c_msg msgs[],int num)1530 qup_i2c_determine_mode_v2(struct qup_i2c_dev *qup,
1531 			  struct i2c_msg msgs[], int num)
1532 {
1533 	int idx;
1534 	bool no_dma = false;
1535 	unsigned int max_tx_len = 0, max_rx_len = 0, total_len = 0;
1536 
1537 	/* All i2c_msgs should be transferred using either dma or cpu */
1538 	for (idx = 0; idx < num; idx++) {
1539 		if (msgs[idx].flags & I2C_M_RD)
1540 			max_rx_len = max_t(unsigned int, max_rx_len,
1541 					   msgs[idx].len);
1542 		else
1543 			max_tx_len = max_t(unsigned int, max_tx_len,
1544 					   msgs[idx].len);
1545 
1546 		if (is_vmalloc_addr(msgs[idx].buf))
1547 			no_dma = true;
1548 
1549 		total_len += msgs[idx].len;
1550 	}
1551 
1552 	if (!no_dma && qup->is_dma &&
1553 	    (total_len > qup->out_fifo_sz || total_len > qup->in_fifo_sz)) {
1554 		qup->use_dma = true;
1555 	} else {
1556 		qup->blk.is_tx_blk_mode = max_tx_len > qup->out_fifo_sz -
1557 			QUP_MAX_TAGS_LEN;
1558 		qup->blk.is_rx_blk_mode = max_rx_len > qup->in_fifo_sz -
1559 			READ_RX_TAGS_LEN;
1560 	}
1561 
1562 	return 0;
1563 }
1564 
qup_i2c_xfer_v2(struct i2c_adapter * adap,struct i2c_msg msgs[],int num)1565 static int qup_i2c_xfer_v2(struct i2c_adapter *adap,
1566 			   struct i2c_msg msgs[],
1567 			   int num)
1568 {
1569 	struct qup_i2c_dev *qup = i2c_get_adapdata(adap);
1570 	int ret, idx = 0;
1571 
1572 	qup->bus_err = 0;
1573 	qup->qup_err = 0;
1574 
1575 	ret = pm_runtime_get_sync(qup->dev);
1576 	if (ret < 0)
1577 		goto out;
1578 
1579 	ret = qup_i2c_determine_mode_v2(qup, msgs, num);
1580 	if (ret)
1581 		goto out;
1582 
1583 	writel(1, qup->base + QUP_SW_RESET);
1584 	ret = qup_i2c_poll_state(qup, QUP_RESET_STATE);
1585 	if (ret)
1586 		goto out;
1587 
1588 	/* Configure QUP as I2C mini core */
1589 	writel(I2C_MINI_CORE | I2C_N_VAL_V2, qup->base + QUP_CONFIG);
1590 	writel(QUP_V2_TAGS_EN, qup->base + QUP_I2C_MASTER_GEN);
1591 
1592 	if (qup_i2c_poll_state_i2c_master(qup)) {
1593 		ret = -EIO;
1594 		goto out;
1595 	}
1596 
1597 	if (qup->use_dma) {
1598 		reinit_completion(&qup->xfer);
1599 		ret = qup_i2c_bam_xfer(adap, &msgs[0], num);
1600 		qup->use_dma = false;
1601 	} else {
1602 		qup_i2c_conf_mode_v2(qup);
1603 
1604 		for (idx = 0; idx < num; idx++) {
1605 			qup->msg = &msgs[idx];
1606 			qup->is_last = idx == (num - 1);
1607 
1608 			ret = qup_i2c_xfer_v2_msg(qup, idx,
1609 					!!(msgs[idx].flags & I2C_M_RD));
1610 			if (ret)
1611 				break;
1612 		}
1613 		qup->msg = NULL;
1614 	}
1615 
1616 	if (!ret)
1617 		ret = qup_i2c_bus_active(qup, ONE_BYTE);
1618 
1619 	if (!ret)
1620 		qup_i2c_change_state(qup, QUP_RESET_STATE);
1621 
1622 	if (ret == 0)
1623 		ret = num;
1624 out:
1625 	pm_runtime_mark_last_busy(qup->dev);
1626 	pm_runtime_put_autosuspend(qup->dev);
1627 
1628 	return ret;
1629 }
1630 
qup_i2c_func(struct i2c_adapter * adap)1631 static u32 qup_i2c_func(struct i2c_adapter *adap)
1632 {
1633 	return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL_ALL & ~I2C_FUNC_SMBUS_QUICK);
1634 }
1635 
1636 static const struct i2c_algorithm qup_i2c_algo = {
1637 	.xfer = qup_i2c_xfer,
1638 	.functionality = qup_i2c_func,
1639 };
1640 
1641 static const struct i2c_algorithm qup_i2c_algo_v2 = {
1642 	.xfer = qup_i2c_xfer_v2,
1643 	.functionality = qup_i2c_func,
1644 };
1645 
1646 /*
1647  * The QUP block will issue a NACK and STOP on the bus when reaching
1648  * the end of the read, the length of the read is specified as one byte
1649  * which limits the possible read to 256 (QUP_READ_LIMIT) bytes.
1650  */
1651 static const struct i2c_adapter_quirks qup_i2c_quirks = {
1652 	.flags = I2C_AQ_NO_ZERO_LEN,
1653 	.max_read_len = QUP_READ_LIMIT,
1654 };
1655 
1656 static const struct i2c_adapter_quirks qup_i2c_quirks_v2 = {
1657 	.flags = I2C_AQ_NO_ZERO_LEN,
1658 };
1659 
qup_i2c_enable_clocks(struct qup_i2c_dev * qup)1660 static void qup_i2c_enable_clocks(struct qup_i2c_dev *qup)
1661 {
1662 	clk_prepare_enable(qup->clk);
1663 	clk_prepare_enable(qup->pclk);
1664 }
1665 
qup_i2c_disable_clocks(struct qup_i2c_dev * qup)1666 static void qup_i2c_disable_clocks(struct qup_i2c_dev *qup)
1667 {
1668 	u32 config;
1669 
1670 	qup_i2c_change_state(qup, QUP_RESET_STATE);
1671 	clk_disable_unprepare(qup->clk);
1672 	config = readl(qup->base + QUP_CONFIG);
1673 	config |= QUP_CLOCK_AUTO_GATE;
1674 	writel(config, qup->base + QUP_CONFIG);
1675 	qup_i2c_vote_bw(qup, 0);
1676 	clk_disable_unprepare(qup->pclk);
1677 }
1678 
1679 static const struct acpi_device_id qup_i2c_acpi_match[] = {
1680 	{ "QCOM8010"},
1681 	{ }
1682 };
1683 MODULE_DEVICE_TABLE(acpi, qup_i2c_acpi_match);
1684 
qup_i2c_probe(struct platform_device * pdev)1685 static int qup_i2c_probe(struct platform_device *pdev)
1686 {
1687 	static const int blk_sizes[] = {4, 16, 32};
1688 	struct qup_i2c_dev *qup;
1689 	unsigned long one_bit_t;
1690 	u32 io_mode, hw_ver, size;
1691 	int ret, fs_div, hs_div;
1692 	u32 src_clk_freq = DEFAULT_SRC_CLK;
1693 	u32 clk_freq = DEFAULT_CLK_FREQ;
1694 	int blocks;
1695 	bool is_qup_v1;
1696 
1697 	qup = devm_kzalloc(&pdev->dev, sizeof(*qup), GFP_KERNEL);
1698 	if (!qup)
1699 		return -ENOMEM;
1700 
1701 	qup->dev = &pdev->dev;
1702 	init_completion(&qup->xfer);
1703 	platform_set_drvdata(pdev, qup);
1704 
1705 	if (scl_freq) {
1706 		dev_notice(qup->dev, "Using override frequency of %u\n", scl_freq);
1707 		clk_freq = scl_freq;
1708 	} else {
1709 		ret = device_property_read_u32(qup->dev, "clock-frequency", &clk_freq);
1710 		if (ret) {
1711 			dev_notice(qup->dev, "using default clock-frequency %d",
1712 				DEFAULT_CLK_FREQ);
1713 		}
1714 	}
1715 
1716 	if (device_is_compatible(&pdev->dev, "qcom,i2c-qup-v1.1.1")) {
1717 		qup->adap.algo = &qup_i2c_algo;
1718 		qup->adap.quirks = &qup_i2c_quirks;
1719 		is_qup_v1 = true;
1720 	} else {
1721 		qup->adap.algo = &qup_i2c_algo_v2;
1722 		qup->adap.quirks = &qup_i2c_quirks_v2;
1723 		is_qup_v1 = false;
1724 		if (acpi_match_device(qup_i2c_acpi_match, qup->dev))
1725 			goto nodma;
1726 		else
1727 			ret = qup_i2c_req_dma(qup);
1728 
1729 		if (ret == -EPROBE_DEFER)
1730 			goto fail_dma;
1731 		else if (ret != 0)
1732 			goto nodma;
1733 
1734 		qup->max_xfer_sg_len = (MX_BLOCKS << 1);
1735 		blocks = (MX_DMA_BLOCKS << 1) + 1;
1736 		qup->btx.sg = devm_kcalloc(&pdev->dev,
1737 					   blocks, sizeof(*qup->btx.sg),
1738 					   GFP_KERNEL);
1739 		if (!qup->btx.sg) {
1740 			ret = -ENOMEM;
1741 			goto fail_dma;
1742 		}
1743 		sg_init_table(qup->btx.sg, blocks);
1744 
1745 		qup->brx.sg = devm_kcalloc(&pdev->dev,
1746 					   blocks, sizeof(*qup->brx.sg),
1747 					   GFP_KERNEL);
1748 		if (!qup->brx.sg) {
1749 			ret = -ENOMEM;
1750 			goto fail_dma;
1751 		}
1752 		sg_init_table(qup->brx.sg, blocks);
1753 
1754 		/* 2 tag bytes for each block + 5 for start, stop tags */
1755 		size = blocks * 2 + 5;
1756 
1757 		qup->start_tag.start = devm_kzalloc(&pdev->dev,
1758 						    size, GFP_KERNEL);
1759 		if (!qup->start_tag.start) {
1760 			ret = -ENOMEM;
1761 			goto fail_dma;
1762 		}
1763 
1764 		qup->brx.tag.start = devm_kzalloc(&pdev->dev, 2, GFP_KERNEL);
1765 		if (!qup->brx.tag.start) {
1766 			ret = -ENOMEM;
1767 			goto fail_dma;
1768 		}
1769 
1770 		qup->btx.tag.start = devm_kzalloc(&pdev->dev, 2, GFP_KERNEL);
1771 		if (!qup->btx.tag.start) {
1772 			ret = -ENOMEM;
1773 			goto fail_dma;
1774 		}
1775 		qup->is_dma = true;
1776 
1777 		qup->icc_path = devm_of_icc_get(&pdev->dev, NULL);
1778 		if (IS_ERR(qup->icc_path))
1779 			return dev_err_probe(&pdev->dev, PTR_ERR(qup->icc_path),
1780 					     "failed to get interconnect path\n");
1781 	}
1782 
1783 nodma:
1784 	/* We support frequencies up to FAST Mode Plus (1MHz) */
1785 	if (!clk_freq || clk_freq > I2C_MAX_FAST_MODE_PLUS_FREQ) {
1786 		dev_err(qup->dev, "clock frequency not supported %d\n",
1787 			clk_freq);
1788 		ret = -EINVAL;
1789 		goto fail_dma;
1790 	}
1791 
1792 	qup->base = devm_platform_ioremap_resource(pdev, 0);
1793 	if (IS_ERR(qup->base)) {
1794 		ret = PTR_ERR(qup->base);
1795 		goto fail_dma;
1796 	}
1797 
1798 	qup->irq = platform_get_irq(pdev, 0);
1799 	if (qup->irq < 0) {
1800 		ret = qup->irq;
1801 		goto fail_dma;
1802 	}
1803 
1804 	if (has_acpi_companion(qup->dev)) {
1805 		ret = device_property_read_u32(qup->dev,
1806 				"src-clock-hz", &src_clk_freq);
1807 		if (ret) {
1808 			dev_notice(qup->dev, "using default src-clock-hz %d",
1809 				DEFAULT_SRC_CLK);
1810 		}
1811 		ACPI_COMPANION_SET(&qup->adap.dev, ACPI_COMPANION(qup->dev));
1812 	} else {
1813 		qup->clk = devm_clk_get(qup->dev, "core");
1814 		if (IS_ERR(qup->clk)) {
1815 			dev_err(qup->dev, "Could not get core clock\n");
1816 			ret = PTR_ERR(qup->clk);
1817 			goto fail_dma;
1818 		}
1819 
1820 		qup->pclk = devm_clk_get(qup->dev, "iface");
1821 		if (IS_ERR(qup->pclk)) {
1822 			dev_err(qup->dev, "Could not get iface clock\n");
1823 			ret = PTR_ERR(qup->pclk);
1824 			goto fail_dma;
1825 		}
1826 		qup_i2c_enable_clocks(qup);
1827 		src_clk_freq = clk_get_rate(qup->clk);
1828 	}
1829 	qup->src_clk_freq = src_clk_freq;
1830 
1831 	/*
1832 	 * Bootloaders might leave a pending interrupt on certain QUP's,
1833 	 * so we reset the core before registering for interrupts.
1834 	 */
1835 	writel(1, qup->base + QUP_SW_RESET);
1836 	ret = qup_i2c_poll_state_valid(qup);
1837 	if (ret)
1838 		goto fail;
1839 
1840 	ret = devm_request_irq(qup->dev, qup->irq, qup_i2c_interrupt,
1841 			       IRQF_TRIGGER_HIGH | IRQF_NO_AUTOEN,
1842 			       "i2c_qup", qup);
1843 	if (ret) {
1844 		dev_err(qup->dev, "Request %d IRQ failed\n", qup->irq);
1845 		goto fail;
1846 	}
1847 
1848 	hw_ver = readl(qup->base + QUP_HW_VERSION);
1849 	dev_dbg(qup->dev, "Revision %x\n", hw_ver);
1850 
1851 	io_mode = readl(qup->base + QUP_IO_MODE);
1852 
1853 	/*
1854 	 * The block/fifo size w.r.t. 'actual data' is 1/2 due to 'tag'
1855 	 * associated with each byte written/received
1856 	 */
1857 	size = QUP_OUTPUT_BLOCK_SIZE(io_mode);
1858 	if (size >= ARRAY_SIZE(blk_sizes)) {
1859 		ret = -EIO;
1860 		goto fail;
1861 	}
1862 	qup->out_blk_sz = blk_sizes[size];
1863 
1864 	size = QUP_INPUT_BLOCK_SIZE(io_mode);
1865 	if (size >= ARRAY_SIZE(blk_sizes)) {
1866 		ret = -EIO;
1867 		goto fail;
1868 	}
1869 	qup->in_blk_sz = blk_sizes[size];
1870 
1871 	if (is_qup_v1) {
1872 		/*
1873 		 * in QUP v1, QUP_CONFIG uses N as 15 i.e 16 bits constitutes a
1874 		 * single transfer but the block size is in bytes so divide the
1875 		 * in_blk_sz and out_blk_sz by 2
1876 		 */
1877 		qup->in_blk_sz /= 2;
1878 		qup->out_blk_sz /= 2;
1879 		qup->write_tx_fifo = qup_i2c_write_tx_fifo_v1;
1880 		qup->read_rx_fifo = qup_i2c_read_rx_fifo_v1;
1881 		qup->write_rx_tags = qup_i2c_write_rx_tags_v1;
1882 	} else {
1883 		qup->write_tx_fifo = qup_i2c_write_tx_fifo_v2;
1884 		qup->read_rx_fifo = qup_i2c_read_rx_fifo_v2;
1885 		qup->write_rx_tags = qup_i2c_write_rx_tags_v2;
1886 	}
1887 
1888 	size = QUP_OUTPUT_FIFO_SIZE(io_mode);
1889 	qup->out_fifo_sz = qup->out_blk_sz * (2 << size);
1890 
1891 	size = QUP_INPUT_FIFO_SIZE(io_mode);
1892 	qup->in_fifo_sz = qup->in_blk_sz * (2 << size);
1893 
1894 	hs_div = 3;
1895 	if (clk_freq <= I2C_MAX_STANDARD_MODE_FREQ) {
1896 		fs_div = ((src_clk_freq / clk_freq) / 2) - 3;
1897 		qup->clk_ctl = (hs_div << 8) | (fs_div & 0xff);
1898 	} else {
1899 		/* 33%/66% duty cycle */
1900 		fs_div = ((src_clk_freq / clk_freq) - 6) * 2 / 3;
1901 		qup->clk_ctl = ((fs_div / 2) << 16) | (hs_div << 8) | (fs_div & 0xff);
1902 	}
1903 
1904 	/*
1905 	 * Time it takes for a byte to be clocked out on the bus.
1906 	 * Each byte takes 9 clock cycles (8 bits + 1 ack).
1907 	 */
1908 	one_bit_t = (USEC_PER_SEC / clk_freq) + 1;
1909 	qup->one_byte_t = one_bit_t * 9;
1910 	qup->xfer_timeout = TOUT_MIN * HZ +
1911 		usecs_to_jiffies(MX_DMA_TX_RX_LEN * qup->one_byte_t);
1912 
1913 	dev_dbg(qup->dev, "IN:block:%d, fifo:%d, OUT:block:%d, fifo:%d\n",
1914 		qup->in_blk_sz, qup->in_fifo_sz,
1915 		qup->out_blk_sz, qup->out_fifo_sz);
1916 
1917 	i2c_set_adapdata(&qup->adap, qup);
1918 	qup->adap.dev.parent = qup->dev;
1919 	qup->adap.dev.of_node = pdev->dev.of_node;
1920 	qup->is_last = true;
1921 
1922 	strscpy(qup->adap.name, "QUP I2C adapter", sizeof(qup->adap.name));
1923 
1924 	pm_runtime_set_autosuspend_delay(qup->dev, MSEC_PER_SEC);
1925 	pm_runtime_use_autosuspend(qup->dev);
1926 	pm_runtime_set_active(qup->dev);
1927 	pm_runtime_enable(qup->dev);
1928 
1929 	ret = i2c_add_adapter(&qup->adap);
1930 	if (ret)
1931 		goto fail_runtime;
1932 
1933 	return 0;
1934 
1935 fail_runtime:
1936 	pm_runtime_disable(qup->dev);
1937 	pm_runtime_set_suspended(qup->dev);
1938 fail:
1939 	qup_i2c_disable_clocks(qup);
1940 fail_dma:
1941 	if (qup->btx.dma)
1942 		dma_release_channel(qup->btx.dma);
1943 	if (qup->brx.dma)
1944 		dma_release_channel(qup->brx.dma);
1945 	return ret;
1946 }
1947 
qup_i2c_remove(struct platform_device * pdev)1948 static void qup_i2c_remove(struct platform_device *pdev)
1949 {
1950 	struct qup_i2c_dev *qup = platform_get_drvdata(pdev);
1951 
1952 	if (qup->is_dma) {
1953 		dma_release_channel(qup->btx.dma);
1954 		dma_release_channel(qup->brx.dma);
1955 	}
1956 
1957 	disable_irq(qup->irq);
1958 	qup_i2c_disable_clocks(qup);
1959 	i2c_del_adapter(&qup->adap);
1960 	pm_runtime_disable(qup->dev);
1961 	pm_runtime_set_suspended(qup->dev);
1962 }
1963 
qup_i2c_pm_suspend_runtime(struct device * device)1964 static int qup_i2c_pm_suspend_runtime(struct device *device)
1965 {
1966 	struct qup_i2c_dev *qup = dev_get_drvdata(device);
1967 
1968 	dev_dbg(device, "pm_runtime: suspending...\n");
1969 	qup_i2c_disable_clocks(qup);
1970 	return 0;
1971 }
1972 
qup_i2c_pm_resume_runtime(struct device * device)1973 static int qup_i2c_pm_resume_runtime(struct device *device)
1974 {
1975 	struct qup_i2c_dev *qup = dev_get_drvdata(device);
1976 
1977 	dev_dbg(device, "pm_runtime: resuming...\n");
1978 	qup_i2c_enable_clocks(qup);
1979 	return 0;
1980 }
1981 
qup_i2c_suspend(struct device * device)1982 static int qup_i2c_suspend(struct device *device)
1983 {
1984 	if (!pm_runtime_suspended(device))
1985 		return qup_i2c_pm_suspend_runtime(device);
1986 	return 0;
1987 }
1988 
qup_i2c_resume(struct device * device)1989 static int qup_i2c_resume(struct device *device)
1990 {
1991 	qup_i2c_pm_resume_runtime(device);
1992 	pm_runtime_mark_last_busy(device);
1993 	pm_request_autosuspend(device);
1994 	return 0;
1995 }
1996 
1997 static const struct dev_pm_ops qup_i2c_qup_pm_ops = {
1998 	SYSTEM_SLEEP_PM_OPS(qup_i2c_suspend, qup_i2c_resume)
1999 	RUNTIME_PM_OPS(qup_i2c_pm_suspend_runtime,
2000 		       qup_i2c_pm_resume_runtime, NULL)
2001 };
2002 
2003 static const struct of_device_id qup_i2c_dt_match[] = {
2004 	{ .compatible = "qcom,i2c-qup-v1.1.1" },
2005 	{ .compatible = "qcom,i2c-qup-v2.1.1" },
2006 	{ .compatible = "qcom,i2c-qup-v2.2.1" },
2007 	{}
2008 };
2009 MODULE_DEVICE_TABLE(of, qup_i2c_dt_match);
2010 
2011 static struct platform_driver qup_i2c_driver = {
2012 	.probe  = qup_i2c_probe,
2013 	.remove = qup_i2c_remove,
2014 	.driver = {
2015 		.name = "i2c_qup",
2016 		.pm = pm_ptr(&qup_i2c_qup_pm_ops),
2017 		.of_match_table = qup_i2c_dt_match,
2018 		.acpi_match_table = ACPI_PTR(qup_i2c_acpi_match),
2019 	},
2020 };
2021 
2022 module_platform_driver(qup_i2c_driver);
2023 
2024 MODULE_DESCRIPTION("Qualcomm QUP based I2C controller");
2025 MODULE_LICENSE("GPL v2");
2026 MODULE_ALIAS("platform:i2c_qup");
2027