xref: /linux/drivers/i2c/busses/i2c-qup.c (revision 70dbb12e95ec7585c68cb3ceae971688915021e3)
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/interrupt.h>
18 #include <linux/io.h>
19 #include <linux/module.h>
20 #include <linux/platform_device.h>
21 #include <linux/pm_runtime.h>
22 #include <linux/property.h>
23 #include <linux/scatterlist.h>
24 
25 /* QUP Registers */
26 #define QUP_CONFIG		0x000
27 #define QUP_STATE		0x004
28 #define QUP_IO_MODE		0x008
29 #define QUP_SW_RESET		0x00c
30 #define QUP_OPERATIONAL		0x018
31 #define QUP_ERROR_FLAGS		0x01c
32 #define QUP_ERROR_FLAGS_EN	0x020
33 #define QUP_OPERATIONAL_MASK	0x028
34 #define QUP_HW_VERSION		0x030
35 #define QUP_MX_OUTPUT_CNT	0x100
36 #define QUP_OUT_FIFO_BASE	0x110
37 #define QUP_MX_WRITE_CNT	0x150
38 #define QUP_MX_INPUT_CNT	0x200
39 #define QUP_MX_READ_CNT		0x208
40 #define QUP_IN_FIFO_BASE	0x218
41 #define QUP_I2C_CLK_CTL		0x400
42 #define QUP_I2C_STATUS		0x404
43 #define QUP_I2C_MASTER_GEN	0x408
44 
45 /* QUP States and reset values */
46 #define QUP_RESET_STATE		0
47 #define QUP_RUN_STATE		1
48 #define QUP_PAUSE_STATE		3
49 #define QUP_STATE_MASK		3
50 
51 #define QUP_STATE_VALID		BIT(2)
52 #define QUP_I2C_MAST_GEN	BIT(4)
53 #define QUP_I2C_FLUSH		BIT(6)
54 
55 #define QUP_OPERATIONAL_RESET	0x000ff0
56 #define QUP_I2C_STATUS_RESET	0xfffffc
57 
58 /* QUP OPERATIONAL FLAGS */
59 #define QUP_I2C_NACK_FLAG	BIT(3)
60 #define QUP_OUT_NOT_EMPTY	BIT(4)
61 #define QUP_IN_NOT_EMPTY	BIT(5)
62 #define QUP_OUT_FULL		BIT(6)
63 #define QUP_OUT_SVC_FLAG	BIT(8)
64 #define QUP_IN_SVC_FLAG		BIT(9)
65 #define QUP_MX_OUTPUT_DONE	BIT(10)
66 #define QUP_MX_INPUT_DONE	BIT(11)
67 #define OUT_BLOCK_WRITE_REQ	BIT(12)
68 #define IN_BLOCK_READ_REQ	BIT(13)
69 
70 /* I2C mini core related values */
71 #define QUP_NO_INPUT		BIT(7)
72 #define QUP_CLOCK_AUTO_GATE	BIT(13)
73 #define I2C_MINI_CORE		(2 << 8)
74 #define I2C_N_VAL		15
75 #define I2C_N_VAL_V2		7
76 
77 /* Most significant word offset in FIFO port */
78 #define QUP_MSW_SHIFT		(I2C_N_VAL + 1)
79 
80 /* Packing/Unpacking words in FIFOs, and IO modes */
81 #define QUP_OUTPUT_BLK_MODE	(1 << 10)
82 #define QUP_OUTPUT_BAM_MODE	(3 << 10)
83 #define QUP_INPUT_BLK_MODE	(1 << 12)
84 #define QUP_INPUT_BAM_MODE	(3 << 12)
85 #define QUP_BAM_MODE		(QUP_OUTPUT_BAM_MODE | QUP_INPUT_BAM_MODE)
86 #define QUP_UNPACK_EN		BIT(14)
87 #define QUP_PACK_EN		BIT(15)
88 
89 #define QUP_REPACK_EN		(QUP_UNPACK_EN | QUP_PACK_EN)
90 #define QUP_V2_TAGS_EN		1
91 
92 #define QUP_OUTPUT_BLOCK_SIZE(x)(((x) >> 0) & 0x03)
93 #define QUP_OUTPUT_FIFO_SIZE(x)	(((x) >> 2) & 0x07)
94 #define QUP_INPUT_BLOCK_SIZE(x)	(((x) >> 5) & 0x03)
95 #define QUP_INPUT_FIFO_SIZE(x)	(((x) >> 7) & 0x07)
96 
97 /* QUP tags */
98 #define QUP_TAG_START		(1 << 8)
99 #define QUP_TAG_DATA		(2 << 8)
100 #define QUP_TAG_STOP		(3 << 8)
101 #define QUP_TAG_REC		(4 << 8)
102 #define QUP_BAM_INPUT_EOT		0x93
103 #define QUP_BAM_FLUSH_STOP		0x96
104 
105 /* QUP v2 tags */
106 #define QUP_TAG_V2_START               0x81
107 #define QUP_TAG_V2_DATAWR              0x82
108 #define QUP_TAG_V2_DATAWR_STOP         0x83
109 #define QUP_TAG_V2_DATARD              0x85
110 #define QUP_TAG_V2_DATARD_NACK         0x86
111 #define QUP_TAG_V2_DATARD_STOP         0x87
112 
113 /* Status, Error flags */
114 #define I2C_STATUS_WR_BUFFER_FULL	BIT(0)
115 #define I2C_STATUS_BUS_ACTIVE		BIT(8)
116 #define I2C_STATUS_ERROR_MASK		0x38000fc
117 #define QUP_STATUS_ERROR_FLAGS		0x7c
118 
119 #define QUP_READ_LIMIT			256
120 #define SET_BIT				0x1
121 #define RESET_BIT			0x0
122 #define ONE_BYTE			0x1
123 #define QUP_I2C_MX_CONFIG_DURING_RUN   BIT(31)
124 
125 /* Maximum transfer length for single DMA descriptor */
126 #define MX_TX_RX_LEN			SZ_64K
127 #define MX_BLOCKS			(MX_TX_RX_LEN / QUP_READ_LIMIT)
128 /* Maximum transfer length for all DMA descriptors */
129 #define MX_DMA_TX_RX_LEN		(2 * MX_TX_RX_LEN)
130 #define MX_DMA_BLOCKS			(MX_DMA_TX_RX_LEN / QUP_READ_LIMIT)
131 
132 /*
133  * Minimum transfer timeout for i2c transfers in seconds. It will be added on
134  * the top of maximum transfer time calculated from i2c bus speed to compensate
135  * the overheads.
136  */
137 #define TOUT_MIN			2
138 
139 /* Default values. Use these if FW query fails */
140 #define DEFAULT_CLK_FREQ I2C_MAX_STANDARD_MODE_FREQ
141 #define DEFAULT_SRC_CLK 20000000
142 
143 /*
144  * Max tags length (start, stop and maximum 2 bytes address) for each QUP
145  * data transfer
146  */
147 #define QUP_MAX_TAGS_LEN		4
148 /* Max data length for each DATARD tags */
149 #define RECV_MAX_DATA_LEN		254
150 /* TAG length for DATA READ in RX FIFO  */
151 #define READ_RX_TAGS_LEN		2
152 
153 static unsigned int scl_freq;
154 module_param_named(scl_freq, scl_freq, uint, 0444);
155 MODULE_PARM_DESC(scl_freq, "SCL frequency override");
156 
157 /*
158  * count: no of blocks
159  * pos: current block number
160  * tx_tag_len: tx tag length for current block
161  * rx_tag_len: rx tag length for current block
162  * data_len: remaining data length for current message
163  * cur_blk_len: data length for current block
164  * total_tx_len: total tx length including tag bytes for current QUP transfer
165  * total_rx_len: total rx length including tag bytes for current QUP transfer
166  * tx_fifo_data_pos: current byte number in TX FIFO word
167  * tx_fifo_free: number of free bytes in current QUP block write.
168  * rx_fifo_data_pos: current byte number in RX FIFO word
169  * fifo_available: number of available bytes in RX FIFO for current
170  *		   QUP block read
171  * tx_fifo_data: QUP TX FIFO write works on word basis (4 bytes). New byte write
172  *		 to TX FIFO will be appended in this data and will be written to
173  *		 TX FIFO when all the 4 bytes are available.
174  * rx_fifo_data: QUP RX FIFO read works on word basis (4 bytes). This will
175  *		 contains the 4 bytes of RX data.
176  * cur_data: pointer to tell cur data position for current message
177  * cur_tx_tags: pointer to tell cur position in tags
178  * tx_tags_sent: all tx tag bytes have been written in FIFO word
179  * send_last_word: for tx FIFO, last word send is pending in current block
180  * rx_bytes_read: if all the bytes have been read from rx FIFO.
181  * rx_tags_fetched: all the rx tag bytes have been fetched from rx fifo word
182  * is_tx_blk_mode: whether tx uses block or FIFO mode in case of non BAM xfer.
183  * is_rx_blk_mode: whether rx uses block or FIFO mode in case of non BAM xfer.
184  * tags: contains tx tag bytes for current QUP transfer
185  */
186 struct qup_i2c_block {
187 	int		count;
188 	int		pos;
189 	int		tx_tag_len;
190 	int		rx_tag_len;
191 	int		data_len;
192 	int		cur_blk_len;
193 	int		total_tx_len;
194 	int		total_rx_len;
195 	int		tx_fifo_data_pos;
196 	int		tx_fifo_free;
197 	int		rx_fifo_data_pos;
198 	int		fifo_available;
199 	u32		tx_fifo_data;
200 	u32		rx_fifo_data;
201 	u8		*cur_data;
202 	u8		*cur_tx_tags;
203 	bool		tx_tags_sent;
204 	bool		send_last_word;
205 	bool		rx_tags_fetched;
206 	bool		rx_bytes_read;
207 	bool		is_tx_blk_mode;
208 	bool		is_rx_blk_mode;
209 	u8		tags[6];
210 };
211 
212 struct qup_i2c_tag {
213 	u8 *start;
214 	dma_addr_t addr;
215 };
216 
217 struct qup_i2c_bam {
218 	struct	qup_i2c_tag tag;
219 	struct	dma_chan *dma;
220 	struct	scatterlist *sg;
221 	unsigned int sg_cnt;
222 };
223 
224 struct qup_i2c_dev {
225 	struct device		*dev;
226 	void __iomem		*base;
227 	int			irq;
228 	struct clk		*clk;
229 	struct clk		*pclk;
230 	struct i2c_adapter	adap;
231 
232 	int			clk_ctl;
233 	int			out_fifo_sz;
234 	int			in_fifo_sz;
235 	int			out_blk_sz;
236 	int			in_blk_sz;
237 
238 	int			blk_xfer_limit;
239 	unsigned long		one_byte_t;
240 	unsigned long		xfer_timeout;
241 	struct qup_i2c_block	blk;
242 
243 	struct i2c_msg		*msg;
244 	/* Current posion in user message buffer */
245 	int			pos;
246 	/* I2C protocol errors */
247 	u32			bus_err;
248 	/* QUP core errors */
249 	u32			qup_err;
250 
251 	/* To check if this is the last msg */
252 	bool			is_last;
253 	bool			is_smbus_read;
254 
255 	/* To configure when bus is in run state */
256 	u32			config_run;
257 
258 	/* dma parameters */
259 	bool			is_dma;
260 	/* To check if the current transfer is using DMA */
261 	bool			use_dma;
262 	unsigned int		max_xfer_sg_len;
263 	unsigned int		tag_buf_pos;
264 	/* The threshold length above which block mode will be used */
265 	unsigned int		blk_mode_threshold;
266 	struct			dma_pool *dpool;
267 	struct			qup_i2c_tag start_tag;
268 	struct			qup_i2c_bam brx;
269 	struct			qup_i2c_bam btx;
270 
271 	struct completion	xfer;
272 	/* function to write data in tx fifo */
273 	void (*write_tx_fifo)(struct qup_i2c_dev *qup);
274 	/* function to read data from rx fifo */
275 	void (*read_rx_fifo)(struct qup_i2c_dev *qup);
276 	/* function to write tags in tx fifo for i2c read transfer */
277 	void (*write_rx_tags)(struct qup_i2c_dev *qup);
278 };
279 
qup_i2c_interrupt(int irq,void * dev)280 static irqreturn_t qup_i2c_interrupt(int irq, void *dev)
281 {
282 	struct qup_i2c_dev *qup = dev;
283 	struct qup_i2c_block *blk = &qup->blk;
284 	u32 bus_err;
285 	u32 qup_err;
286 	u32 opflags;
287 
288 	bus_err = readl(qup->base + QUP_I2C_STATUS);
289 	qup_err = readl(qup->base + QUP_ERROR_FLAGS);
290 	opflags = readl(qup->base + QUP_OPERATIONAL);
291 
292 	if (!qup->msg) {
293 		/* Clear Error interrupt */
294 		writel(QUP_RESET_STATE, qup->base + QUP_STATE);
295 		return IRQ_HANDLED;
296 	}
297 
298 	bus_err &= I2C_STATUS_ERROR_MASK;
299 	qup_err &= QUP_STATUS_ERROR_FLAGS;
300 
301 	/* Clear the error bits in QUP_ERROR_FLAGS */
302 	if (qup_err)
303 		writel(qup_err, qup->base + QUP_ERROR_FLAGS);
304 
305 	/* Clear the error bits in QUP_I2C_STATUS */
306 	if (bus_err)
307 		writel(bus_err, qup->base + QUP_I2C_STATUS);
308 
309 	/*
310 	 * Check for BAM mode and returns if already error has come for current
311 	 * transfer. In Error case, sometimes, QUP generates more than one
312 	 * interrupt.
313 	 */
314 	if (qup->use_dma && (qup->qup_err || qup->bus_err))
315 		return IRQ_HANDLED;
316 
317 	/* Reset the QUP State in case of error */
318 	if (qup_err || bus_err) {
319 		/*
320 		 * Don’t reset the QUP state in case of BAM mode. The BAM
321 		 * flush operation needs to be scheduled in transfer function
322 		 * which will clear the remaining schedule descriptors in BAM
323 		 * HW FIFO and generates the BAM interrupt.
324 		 */
325 		if (!qup->use_dma)
326 			writel(QUP_RESET_STATE, qup->base + QUP_STATE);
327 		goto done;
328 	}
329 
330 	if (opflags & QUP_OUT_SVC_FLAG) {
331 		writel(QUP_OUT_SVC_FLAG, qup->base + QUP_OPERATIONAL);
332 
333 		if (opflags & OUT_BLOCK_WRITE_REQ) {
334 			blk->tx_fifo_free += qup->out_blk_sz;
335 			if (qup->msg->flags & I2C_M_RD)
336 				qup->write_rx_tags(qup);
337 			else
338 				qup->write_tx_fifo(qup);
339 		}
340 	}
341 
342 	if (opflags & QUP_IN_SVC_FLAG) {
343 		writel(QUP_IN_SVC_FLAG, qup->base + QUP_OPERATIONAL);
344 
345 		if (!blk->is_rx_blk_mode) {
346 			blk->fifo_available += qup->in_fifo_sz;
347 			qup->read_rx_fifo(qup);
348 		} else if (opflags & IN_BLOCK_READ_REQ) {
349 			blk->fifo_available += qup->in_blk_sz;
350 			qup->read_rx_fifo(qup);
351 		}
352 	}
353 
354 	if (qup->msg->flags & I2C_M_RD) {
355 		if (!blk->rx_bytes_read)
356 			return IRQ_HANDLED;
357 	} else {
358 		/*
359 		 * Ideally, QUP_MAX_OUTPUT_DONE_FLAG should be checked
360 		 * for FIFO mode also. But, QUP_MAX_OUTPUT_DONE_FLAG lags
361 		 * behind QUP_OUTPUT_SERVICE_FLAG sometimes. The only reason
362 		 * of interrupt for write message in FIFO mode is
363 		 * QUP_MAX_OUTPUT_DONE_FLAG condition.
364 		 */
365 		if (blk->is_tx_blk_mode && !(opflags & QUP_MX_OUTPUT_DONE))
366 			return IRQ_HANDLED;
367 	}
368 
369 done:
370 	qup->qup_err = qup_err;
371 	qup->bus_err = bus_err;
372 	complete(&qup->xfer);
373 	return IRQ_HANDLED;
374 }
375 
qup_i2c_poll_state_mask(struct qup_i2c_dev * qup,u32 req_state,u32 req_mask)376 static int qup_i2c_poll_state_mask(struct qup_i2c_dev *qup,
377 				   u32 req_state, u32 req_mask)
378 {
379 	int retries = 1;
380 	u32 state;
381 
382 	/*
383 	 * State transition takes 3 AHB clocks cycles + 3 I2C master clock
384 	 * cycles. So retry once after a 1uS delay.
385 	 */
386 	do {
387 		state = readl(qup->base + QUP_STATE);
388 
389 		if (state & QUP_STATE_VALID &&
390 		    (state & req_mask) == req_state)
391 			return 0;
392 
393 		udelay(1);
394 	} while (retries--);
395 
396 	return -ETIMEDOUT;
397 }
398 
qup_i2c_poll_state(struct qup_i2c_dev * qup,u32 req_state)399 static int qup_i2c_poll_state(struct qup_i2c_dev *qup, u32 req_state)
400 {
401 	return qup_i2c_poll_state_mask(qup, req_state, QUP_STATE_MASK);
402 }
403 
qup_i2c_flush(struct qup_i2c_dev * qup)404 static void qup_i2c_flush(struct qup_i2c_dev *qup)
405 {
406 	u32 val = readl(qup->base + QUP_STATE);
407 
408 	val |= QUP_I2C_FLUSH;
409 	writel(val, qup->base + QUP_STATE);
410 }
411 
qup_i2c_poll_state_valid(struct qup_i2c_dev * qup)412 static int qup_i2c_poll_state_valid(struct qup_i2c_dev *qup)
413 {
414 	return qup_i2c_poll_state_mask(qup, 0, 0);
415 }
416 
qup_i2c_poll_state_i2c_master(struct qup_i2c_dev * qup)417 static int qup_i2c_poll_state_i2c_master(struct qup_i2c_dev *qup)
418 {
419 	return qup_i2c_poll_state_mask(qup, QUP_I2C_MAST_GEN, QUP_I2C_MAST_GEN);
420 }
421 
qup_i2c_change_state(struct qup_i2c_dev * qup,u32 state)422 static int qup_i2c_change_state(struct qup_i2c_dev *qup, u32 state)
423 {
424 	if (qup_i2c_poll_state_valid(qup) != 0)
425 		return -EIO;
426 
427 	writel(state, qup->base + QUP_STATE);
428 
429 	if (qup_i2c_poll_state(qup, state) != 0)
430 		return -EIO;
431 	return 0;
432 }
433 
434 /* Check if I2C bus returns to IDLE state */
qup_i2c_bus_active(struct qup_i2c_dev * qup,int len)435 static int qup_i2c_bus_active(struct qup_i2c_dev *qup, int len)
436 {
437 	unsigned long timeout;
438 	u32 status;
439 	int ret = 0;
440 
441 	timeout = jiffies + len * 4;
442 	for (;;) {
443 		status = readl(qup->base + QUP_I2C_STATUS);
444 		if (!(status & I2C_STATUS_BUS_ACTIVE))
445 			break;
446 
447 		if (time_after(jiffies, timeout))
448 			ret = -ETIMEDOUT;
449 
450 		usleep_range(len, len * 2);
451 	}
452 
453 	return ret;
454 }
455 
qup_i2c_write_tx_fifo_v1(struct qup_i2c_dev * qup)456 static void qup_i2c_write_tx_fifo_v1(struct qup_i2c_dev *qup)
457 {
458 	struct qup_i2c_block *blk = &qup->blk;
459 	struct i2c_msg *msg = qup->msg;
460 	u32 addr = i2c_8bit_addr_from_msg(msg);
461 	u32 qup_tag;
462 	int idx;
463 	u32 val;
464 
465 	if (qup->pos == 0) {
466 		val = QUP_TAG_START | addr;
467 		idx = 1;
468 		blk->tx_fifo_free--;
469 	} else {
470 		val = 0;
471 		idx = 0;
472 	}
473 
474 	while (blk->tx_fifo_free && qup->pos < msg->len) {
475 		if (qup->pos == msg->len - 1)
476 			qup_tag = QUP_TAG_STOP;
477 		else
478 			qup_tag = QUP_TAG_DATA;
479 
480 		if (idx & 1)
481 			val |= (qup_tag | msg->buf[qup->pos]) << QUP_MSW_SHIFT;
482 		else
483 			val = qup_tag | msg->buf[qup->pos];
484 
485 		/* Write out the pair and the last odd value */
486 		if (idx & 1 || qup->pos == msg->len - 1)
487 			writel(val, qup->base + QUP_OUT_FIFO_BASE);
488 
489 		qup->pos++;
490 		idx++;
491 		blk->tx_fifo_free--;
492 	}
493 }
494 
qup_i2c_set_blk_data(struct qup_i2c_dev * qup,struct i2c_msg * msg)495 static void qup_i2c_set_blk_data(struct qup_i2c_dev *qup,
496 				 struct i2c_msg *msg)
497 {
498 	qup->blk.pos = 0;
499 	qup->blk.data_len = msg->len;
500 	qup->blk.count = DIV_ROUND_UP(msg->len, qup->blk_xfer_limit);
501 }
502 
qup_i2c_get_data_len(struct qup_i2c_dev * qup)503 static int qup_i2c_get_data_len(struct qup_i2c_dev *qup)
504 {
505 	int data_len;
506 
507 	if (qup->blk.data_len > qup->blk_xfer_limit)
508 		data_len = qup->blk_xfer_limit;
509 	else
510 		data_len = qup->blk.data_len;
511 
512 	return data_len;
513 }
514 
qup_i2c_check_msg_len(struct i2c_msg * msg)515 static bool qup_i2c_check_msg_len(struct i2c_msg *msg)
516 {
517 	return ((msg->flags & I2C_M_RD) && (msg->flags & I2C_M_RECV_LEN));
518 }
519 
qup_i2c_set_tags_smb(u16 addr,u8 * tags,struct qup_i2c_dev * qup,struct i2c_msg * msg)520 static int qup_i2c_set_tags_smb(u16 addr, u8 *tags, struct qup_i2c_dev *qup,
521 			struct i2c_msg *msg)
522 {
523 	int len = 0;
524 
525 	if (qup->is_smbus_read) {
526 		tags[len++] = QUP_TAG_V2_DATARD_STOP;
527 		tags[len++] = qup_i2c_get_data_len(qup);
528 	} else {
529 		tags[len++] = QUP_TAG_V2_START;
530 		tags[len++] = addr & 0xff;
531 
532 		if (msg->flags & I2C_M_TEN)
533 			tags[len++] = addr >> 8;
534 
535 		tags[len++] = QUP_TAG_V2_DATARD;
536 		/* Read 1 byte indicating the length of the SMBus message */
537 		tags[len++] = 1;
538 	}
539 	return len;
540 }
541 
qup_i2c_set_tags(u8 * tags,struct qup_i2c_dev * qup,struct i2c_msg * msg)542 static int qup_i2c_set_tags(u8 *tags, struct qup_i2c_dev *qup,
543 			    struct i2c_msg *msg)
544 {
545 	u16 addr = i2c_8bit_addr_from_msg(msg);
546 	int len = 0;
547 	int data_len;
548 
549 	int last = (qup->blk.pos == (qup->blk.count - 1)) && (qup->is_last);
550 
551 	/* Handle tags for SMBus block read */
552 	if (qup_i2c_check_msg_len(msg))
553 		return qup_i2c_set_tags_smb(addr, tags, qup, msg);
554 
555 	if (qup->blk.pos == 0) {
556 		tags[len++] = QUP_TAG_V2_START;
557 		tags[len++] = addr & 0xff;
558 
559 		if (msg->flags & I2C_M_TEN)
560 			tags[len++] = addr >> 8;
561 	}
562 
563 	/* Send _STOP commands for the last block */
564 	if (last) {
565 		if (msg->flags & I2C_M_RD)
566 			tags[len++] = QUP_TAG_V2_DATARD_STOP;
567 		else
568 			tags[len++] = QUP_TAG_V2_DATAWR_STOP;
569 	} else {
570 		if (msg->flags & I2C_M_RD)
571 			tags[len++] = qup->blk.pos == (qup->blk.count - 1) ?
572 				      QUP_TAG_V2_DATARD_NACK :
573 				      QUP_TAG_V2_DATARD;
574 		else
575 			tags[len++] = QUP_TAG_V2_DATAWR;
576 	}
577 
578 	data_len = qup_i2c_get_data_len(qup);
579 
580 	/* 0 implies 256 bytes */
581 	if (data_len == QUP_READ_LIMIT)
582 		tags[len++] = 0;
583 	else
584 		tags[len++] = data_len;
585 
586 	return len;
587 }
588 
589 
qup_i2c_bam_cb(void * data)590 static void qup_i2c_bam_cb(void *data)
591 {
592 	struct qup_i2c_dev *qup = data;
593 
594 	complete(&qup->xfer);
595 }
596 
qup_sg_set_buf(struct scatterlist * sg,void * buf,unsigned int buflen,struct qup_i2c_dev * qup,int dir)597 static int qup_sg_set_buf(struct scatterlist *sg, void *buf,
598 			  unsigned int buflen, struct qup_i2c_dev *qup,
599 			  int dir)
600 {
601 	int ret;
602 
603 	sg_set_buf(sg, buf, buflen);
604 	ret = dma_map_sg(qup->dev, sg, 1, dir);
605 	if (!ret)
606 		return -EINVAL;
607 
608 	return 0;
609 }
610 
qup_i2c_rel_dma(struct qup_i2c_dev * qup)611 static void qup_i2c_rel_dma(struct qup_i2c_dev *qup)
612 {
613 	if (qup->btx.dma)
614 		dma_release_channel(qup->btx.dma);
615 	if (qup->brx.dma)
616 		dma_release_channel(qup->brx.dma);
617 	qup->btx.dma = NULL;
618 	qup->brx.dma = NULL;
619 }
620 
qup_i2c_req_dma(struct qup_i2c_dev * qup)621 static int qup_i2c_req_dma(struct qup_i2c_dev *qup)
622 {
623 	int err;
624 
625 	if (!qup->btx.dma) {
626 		qup->btx.dma = dma_request_chan(qup->dev, "tx");
627 		if (IS_ERR(qup->btx.dma)) {
628 			err = PTR_ERR(qup->btx.dma);
629 			qup->btx.dma = NULL;
630 			dev_err(qup->dev, "\n tx channel not available");
631 			return err;
632 		}
633 	}
634 
635 	if (!qup->brx.dma) {
636 		qup->brx.dma = dma_request_chan(qup->dev, "rx");
637 		if (IS_ERR(qup->brx.dma)) {
638 			dev_err(qup->dev, "\n rx channel not available");
639 			err = PTR_ERR(qup->brx.dma);
640 			qup->brx.dma = NULL;
641 			qup_i2c_rel_dma(qup);
642 			return err;
643 		}
644 	}
645 	return 0;
646 }
647 
qup_i2c_bam_make_desc(struct qup_i2c_dev * qup,struct i2c_msg * msg)648 static int qup_i2c_bam_make_desc(struct qup_i2c_dev *qup, struct i2c_msg *msg)
649 {
650 	int ret = 0, limit = QUP_READ_LIMIT;
651 	u32 len = 0, blocks, rem;
652 	u32 i = 0, tlen, tx_len = 0;
653 	u8 *tags;
654 
655 	qup->blk_xfer_limit = QUP_READ_LIMIT;
656 	qup_i2c_set_blk_data(qup, msg);
657 
658 	blocks = qup->blk.count;
659 	rem = msg->len - (blocks - 1) * limit;
660 
661 	if (msg->flags & I2C_M_RD) {
662 		while (qup->blk.pos < blocks) {
663 			tlen = (i == (blocks - 1)) ? rem : limit;
664 			tags = &qup->start_tag.start[qup->tag_buf_pos + len];
665 			len += qup_i2c_set_tags(tags, qup, msg);
666 			qup->blk.data_len -= tlen;
667 
668 			/* scratch buf to read the start and len tags */
669 			ret = qup_sg_set_buf(&qup->brx.sg[qup->brx.sg_cnt++],
670 					     &qup->brx.tag.start[0],
671 					     2, qup, DMA_FROM_DEVICE);
672 
673 			if (ret)
674 				return ret;
675 
676 			ret = qup_sg_set_buf(&qup->brx.sg[qup->brx.sg_cnt++],
677 					     &msg->buf[limit * i],
678 					     tlen, qup,
679 					     DMA_FROM_DEVICE);
680 			if (ret)
681 				return ret;
682 
683 			i++;
684 			qup->blk.pos = i;
685 		}
686 		ret = qup_sg_set_buf(&qup->btx.sg[qup->btx.sg_cnt++],
687 				     &qup->start_tag.start[qup->tag_buf_pos],
688 				     len, qup, DMA_TO_DEVICE);
689 		if (ret)
690 			return ret;
691 
692 		qup->tag_buf_pos += len;
693 	} else {
694 		while (qup->blk.pos < blocks) {
695 			tlen = (i == (blocks - 1)) ? rem : limit;
696 			tags = &qup->start_tag.start[qup->tag_buf_pos + tx_len];
697 			len = qup_i2c_set_tags(tags, qup, msg);
698 			qup->blk.data_len -= tlen;
699 
700 			ret = qup_sg_set_buf(&qup->btx.sg[qup->btx.sg_cnt++],
701 					     tags, len,
702 					     qup, DMA_TO_DEVICE);
703 			if (ret)
704 				return ret;
705 
706 			tx_len += len;
707 			ret = qup_sg_set_buf(&qup->btx.sg[qup->btx.sg_cnt++],
708 					     &msg->buf[limit * i],
709 					     tlen, qup, DMA_TO_DEVICE);
710 			if (ret)
711 				return ret;
712 			i++;
713 			qup->blk.pos = i;
714 		}
715 
716 		qup->tag_buf_pos += tx_len;
717 	}
718 
719 	return 0;
720 }
721 
qup_i2c_bam_schedule_desc(struct qup_i2c_dev * qup)722 static int qup_i2c_bam_schedule_desc(struct qup_i2c_dev *qup)
723 {
724 	struct dma_async_tx_descriptor *txd, *rxd = NULL;
725 	int ret = 0;
726 	dma_cookie_t cookie_rx, cookie_tx;
727 	u32 len = 0;
728 	u32 tx_cnt = qup->btx.sg_cnt, rx_cnt = qup->brx.sg_cnt;
729 
730 	/* schedule the EOT and FLUSH I2C tags */
731 	len = 1;
732 	if (rx_cnt) {
733 		qup->btx.tag.start[0] = QUP_BAM_INPUT_EOT;
734 		len++;
735 
736 		/* scratch buf to read the BAM EOT FLUSH tags */
737 		ret = qup_sg_set_buf(&qup->brx.sg[rx_cnt++],
738 				     &qup->brx.tag.start[0],
739 				     1, qup, DMA_FROM_DEVICE);
740 		if (ret)
741 			return ret;
742 	}
743 
744 	qup->btx.tag.start[len - 1] = QUP_BAM_FLUSH_STOP;
745 	ret = qup_sg_set_buf(&qup->btx.sg[tx_cnt++], &qup->btx.tag.start[0],
746 			     len, qup, DMA_TO_DEVICE);
747 	if (ret)
748 		return ret;
749 
750 	txd = dmaengine_prep_slave_sg(qup->btx.dma, qup->btx.sg, tx_cnt,
751 				      DMA_MEM_TO_DEV,
752 				      DMA_PREP_INTERRUPT | DMA_PREP_FENCE);
753 	if (!txd) {
754 		dev_err(qup->dev, "failed to get tx desc\n");
755 		ret = -EINVAL;
756 		goto desc_err;
757 	}
758 
759 	if (!rx_cnt) {
760 		txd->callback = qup_i2c_bam_cb;
761 		txd->callback_param = qup;
762 	}
763 
764 	cookie_tx = dmaengine_submit(txd);
765 	if (dma_submit_error(cookie_tx)) {
766 		ret = -EINVAL;
767 		goto desc_err;
768 	}
769 
770 	dma_async_issue_pending(qup->btx.dma);
771 
772 	if (rx_cnt) {
773 		rxd = dmaengine_prep_slave_sg(qup->brx.dma, qup->brx.sg,
774 					      rx_cnt, DMA_DEV_TO_MEM,
775 					      DMA_PREP_INTERRUPT);
776 		if (!rxd) {
777 			dev_err(qup->dev, "failed to get rx desc\n");
778 			ret = -EINVAL;
779 
780 			/* abort TX descriptors */
781 			dmaengine_terminate_sync(qup->btx.dma);
782 			goto desc_err;
783 		}
784 
785 		rxd->callback = qup_i2c_bam_cb;
786 		rxd->callback_param = qup;
787 		cookie_rx = dmaengine_submit(rxd);
788 		if (dma_submit_error(cookie_rx)) {
789 			ret = -EINVAL;
790 			goto desc_err;
791 		}
792 
793 		dma_async_issue_pending(qup->brx.dma);
794 	}
795 
796 	if (!wait_for_completion_timeout(&qup->xfer, qup->xfer_timeout))
797 		ret = -ETIMEDOUT;
798 
799 	if (ret || qup->bus_err || qup->qup_err) {
800 		reinit_completion(&qup->xfer);
801 
802 		ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
803 		if (ret) {
804 			dev_err(qup->dev, "change to run state timed out");
805 			goto desc_err;
806 		}
807 
808 		qup_i2c_flush(qup);
809 
810 		/* wait for remaining interrupts to occur */
811 		if (!wait_for_completion_timeout(&qup->xfer, HZ))
812 			dev_err(qup->dev, "flush timed out\n");
813 
814 		ret =  (qup->bus_err & QUP_I2C_NACK_FLAG) ? -ENXIO : -EIO;
815 	}
816 
817 desc_err:
818 	dma_unmap_sg(qup->dev, qup->btx.sg, tx_cnt, DMA_TO_DEVICE);
819 
820 	if (rx_cnt)
821 		dma_unmap_sg(qup->dev, qup->brx.sg, rx_cnt,
822 			     DMA_FROM_DEVICE);
823 
824 	return ret;
825 }
826 
qup_i2c_bam_clear_tag_buffers(struct qup_i2c_dev * qup)827 static void qup_i2c_bam_clear_tag_buffers(struct qup_i2c_dev *qup)
828 {
829 	qup->btx.sg_cnt = 0;
830 	qup->brx.sg_cnt = 0;
831 	qup->tag_buf_pos = 0;
832 }
833 
qup_i2c_bam_xfer(struct i2c_adapter * adap,struct i2c_msg * msg,int num)834 static int qup_i2c_bam_xfer(struct i2c_adapter *adap, struct i2c_msg *msg,
835 			    int num)
836 {
837 	struct qup_i2c_dev *qup = i2c_get_adapdata(adap);
838 	int ret = 0;
839 	int idx = 0;
840 
841 	enable_irq(qup->irq);
842 	ret = qup_i2c_req_dma(qup);
843 
844 	if (ret)
845 		goto out;
846 
847 	writel(0, qup->base + QUP_MX_INPUT_CNT);
848 	writel(0, qup->base + QUP_MX_OUTPUT_CNT);
849 
850 	/* set BAM mode */
851 	writel(QUP_REPACK_EN | QUP_BAM_MODE, qup->base + QUP_IO_MODE);
852 
853 	/* mask fifo irqs */
854 	writel((0x3 << 8), qup->base + QUP_OPERATIONAL_MASK);
855 
856 	/* set RUN STATE */
857 	ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
858 	if (ret)
859 		goto out;
860 
861 	writel(qup->clk_ctl, qup->base + QUP_I2C_CLK_CTL);
862 	qup_i2c_bam_clear_tag_buffers(qup);
863 
864 	for (idx = 0; idx < num; idx++) {
865 		qup->msg = msg + idx;
866 		qup->is_last = idx == (num - 1);
867 
868 		ret = qup_i2c_bam_make_desc(qup, qup->msg);
869 		if (ret)
870 			break;
871 
872 		/*
873 		 * Make DMA descriptor and schedule the BAM transfer if its
874 		 * already crossed the maximum length. Since the memory for all
875 		 * tags buffers have been taken for 2 maximum possible
876 		 * transfers length so it will never cross the buffer actual
877 		 * length.
878 		 */
879 		if (qup->btx.sg_cnt > qup->max_xfer_sg_len ||
880 		    qup->brx.sg_cnt > qup->max_xfer_sg_len ||
881 		    qup->is_last) {
882 			ret = qup_i2c_bam_schedule_desc(qup);
883 			if (ret)
884 				break;
885 
886 			qup_i2c_bam_clear_tag_buffers(qup);
887 		}
888 	}
889 
890 out:
891 	disable_irq(qup->irq);
892 
893 	qup->msg = NULL;
894 	return ret;
895 }
896 
qup_i2c_wait_for_complete(struct qup_i2c_dev * qup,struct i2c_msg * msg)897 static int qup_i2c_wait_for_complete(struct qup_i2c_dev *qup,
898 				     struct i2c_msg *msg)
899 {
900 	unsigned long left;
901 	int ret = 0;
902 
903 	left = wait_for_completion_timeout(&qup->xfer, qup->xfer_timeout);
904 	if (!left) {
905 		writel(1, qup->base + QUP_SW_RESET);
906 		ret = -ETIMEDOUT;
907 	}
908 
909 	if (qup->bus_err || qup->qup_err)
910 		ret =  (qup->bus_err & QUP_I2C_NACK_FLAG) ? -ENXIO : -EIO;
911 
912 	return ret;
913 }
914 
qup_i2c_read_rx_fifo_v1(struct qup_i2c_dev * qup)915 static void qup_i2c_read_rx_fifo_v1(struct qup_i2c_dev *qup)
916 {
917 	struct qup_i2c_block *blk = &qup->blk;
918 	struct i2c_msg *msg = qup->msg;
919 	u32 val = 0;
920 	int idx = 0;
921 
922 	while (blk->fifo_available && qup->pos < msg->len) {
923 		if ((idx & 1) == 0) {
924 			/* Reading 2 words at time */
925 			val = readl(qup->base + QUP_IN_FIFO_BASE);
926 			msg->buf[qup->pos++] = val & 0xFF;
927 		} else {
928 			msg->buf[qup->pos++] = val >> QUP_MSW_SHIFT;
929 		}
930 		idx++;
931 		blk->fifo_available--;
932 	}
933 
934 	if (qup->pos == msg->len)
935 		blk->rx_bytes_read = true;
936 }
937 
qup_i2c_write_rx_tags_v1(struct qup_i2c_dev * qup)938 static void qup_i2c_write_rx_tags_v1(struct qup_i2c_dev *qup)
939 {
940 	struct i2c_msg *msg = qup->msg;
941 	u32 addr, len, val;
942 
943 	addr = i2c_8bit_addr_from_msg(msg);
944 
945 	/* 0 is used to specify a length 256 (QUP_READ_LIMIT) */
946 	len = (msg->len == QUP_READ_LIMIT) ? 0 : msg->len;
947 
948 	val = ((QUP_TAG_REC | len) << QUP_MSW_SHIFT) | QUP_TAG_START | addr;
949 	writel(val, qup->base + QUP_OUT_FIFO_BASE);
950 }
951 
qup_i2c_conf_v1(struct qup_i2c_dev * qup)952 static void qup_i2c_conf_v1(struct qup_i2c_dev *qup)
953 {
954 	struct qup_i2c_block *blk = &qup->blk;
955 	u32 qup_config = I2C_MINI_CORE | I2C_N_VAL;
956 	u32 io_mode = QUP_REPACK_EN;
957 
958 	blk->is_tx_blk_mode = blk->total_tx_len > qup->out_fifo_sz;
959 	blk->is_rx_blk_mode = blk->total_rx_len > qup->in_fifo_sz;
960 
961 	if (blk->is_tx_blk_mode) {
962 		io_mode |= QUP_OUTPUT_BLK_MODE;
963 		writel(0, qup->base + QUP_MX_WRITE_CNT);
964 		writel(blk->total_tx_len, qup->base + QUP_MX_OUTPUT_CNT);
965 	} else {
966 		writel(0, qup->base + QUP_MX_OUTPUT_CNT);
967 		writel(blk->total_tx_len, qup->base + QUP_MX_WRITE_CNT);
968 	}
969 
970 	if (blk->total_rx_len) {
971 		if (blk->is_rx_blk_mode) {
972 			io_mode |= QUP_INPUT_BLK_MODE;
973 			writel(0, qup->base + QUP_MX_READ_CNT);
974 			writel(blk->total_rx_len, qup->base + QUP_MX_INPUT_CNT);
975 		} else {
976 			writel(0, qup->base + QUP_MX_INPUT_CNT);
977 			writel(blk->total_rx_len, qup->base + QUP_MX_READ_CNT);
978 		}
979 	} else {
980 		qup_config |= QUP_NO_INPUT;
981 	}
982 
983 	writel(qup_config, qup->base + QUP_CONFIG);
984 	writel(io_mode, qup->base + QUP_IO_MODE);
985 }
986 
qup_i2c_clear_blk_v1(struct qup_i2c_block * blk)987 static void qup_i2c_clear_blk_v1(struct qup_i2c_block *blk)
988 {
989 	blk->tx_fifo_free = 0;
990 	blk->fifo_available = 0;
991 	blk->rx_bytes_read = false;
992 }
993 
qup_i2c_conf_xfer_v1(struct qup_i2c_dev * qup,bool is_rx)994 static int qup_i2c_conf_xfer_v1(struct qup_i2c_dev *qup, bool is_rx)
995 {
996 	struct qup_i2c_block *blk = &qup->blk;
997 	int ret;
998 
999 	qup_i2c_clear_blk_v1(blk);
1000 	qup_i2c_conf_v1(qup);
1001 	ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
1002 	if (ret)
1003 		return ret;
1004 
1005 	writel(qup->clk_ctl, qup->base + QUP_I2C_CLK_CTL);
1006 
1007 	ret = qup_i2c_change_state(qup, QUP_PAUSE_STATE);
1008 	if (ret)
1009 		return ret;
1010 
1011 	reinit_completion(&qup->xfer);
1012 	enable_irq(qup->irq);
1013 	if (!blk->is_tx_blk_mode) {
1014 		blk->tx_fifo_free = qup->out_fifo_sz;
1015 
1016 		if (is_rx)
1017 			qup_i2c_write_rx_tags_v1(qup);
1018 		else
1019 			qup_i2c_write_tx_fifo_v1(qup);
1020 	}
1021 
1022 	ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
1023 	if (ret)
1024 		goto err;
1025 
1026 	ret = qup_i2c_wait_for_complete(qup, qup->msg);
1027 	if (ret)
1028 		goto err;
1029 
1030 	ret = qup_i2c_bus_active(qup, ONE_BYTE);
1031 
1032 err:
1033 	disable_irq(qup->irq);
1034 	return ret;
1035 }
1036 
qup_i2c_write_one(struct qup_i2c_dev * qup)1037 static int qup_i2c_write_one(struct qup_i2c_dev *qup)
1038 {
1039 	struct i2c_msg *msg = qup->msg;
1040 	struct qup_i2c_block *blk = &qup->blk;
1041 
1042 	qup->pos = 0;
1043 	blk->total_tx_len = msg->len + 1;
1044 	blk->total_rx_len = 0;
1045 
1046 	return qup_i2c_conf_xfer_v1(qup, false);
1047 }
1048 
qup_i2c_read_one(struct qup_i2c_dev * qup)1049 static int qup_i2c_read_one(struct qup_i2c_dev *qup)
1050 {
1051 	struct qup_i2c_block *blk = &qup->blk;
1052 
1053 	qup->pos = 0;
1054 	blk->total_tx_len = 2;
1055 	blk->total_rx_len = qup->msg->len;
1056 
1057 	return qup_i2c_conf_xfer_v1(qup, true);
1058 }
1059 
qup_i2c_xfer(struct i2c_adapter * adap,struct i2c_msg msgs[],int num)1060 static int qup_i2c_xfer(struct i2c_adapter *adap,
1061 			struct i2c_msg msgs[],
1062 			int num)
1063 {
1064 	struct qup_i2c_dev *qup = i2c_get_adapdata(adap);
1065 	int ret, idx;
1066 
1067 	ret = pm_runtime_get_sync(qup->dev);
1068 	if (ret < 0)
1069 		goto out;
1070 
1071 	qup->bus_err = 0;
1072 	qup->qup_err = 0;
1073 
1074 	writel(1, qup->base + QUP_SW_RESET);
1075 	ret = qup_i2c_poll_state(qup, QUP_RESET_STATE);
1076 	if (ret)
1077 		goto out;
1078 
1079 	/* Configure QUP as I2C mini core */
1080 	writel(I2C_MINI_CORE | I2C_N_VAL, qup->base + QUP_CONFIG);
1081 
1082 	for (idx = 0; idx < num; idx++) {
1083 		if (qup_i2c_poll_state_i2c_master(qup)) {
1084 			ret = -EIO;
1085 			goto out;
1086 		}
1087 
1088 		if (qup_i2c_check_msg_len(&msgs[idx])) {
1089 			ret = -EINVAL;
1090 			goto out;
1091 		}
1092 
1093 		qup->msg = &msgs[idx];
1094 		if (msgs[idx].flags & I2C_M_RD)
1095 			ret = qup_i2c_read_one(qup);
1096 		else
1097 			ret = qup_i2c_write_one(qup);
1098 
1099 		if (ret)
1100 			break;
1101 
1102 		ret = qup_i2c_change_state(qup, QUP_RESET_STATE);
1103 		if (ret)
1104 			break;
1105 	}
1106 
1107 	if (ret == 0)
1108 		ret = num;
1109 out:
1110 
1111 	pm_runtime_mark_last_busy(qup->dev);
1112 	pm_runtime_put_autosuspend(qup->dev);
1113 
1114 	return ret;
1115 }
1116 
1117 /*
1118  * Configure registers related with reconfiguration during run and call it
1119  * before each i2c sub transfer.
1120  */
qup_i2c_conf_count_v2(struct qup_i2c_dev * qup)1121 static void qup_i2c_conf_count_v2(struct qup_i2c_dev *qup)
1122 {
1123 	struct qup_i2c_block *blk = &qup->blk;
1124 	u32 qup_config = I2C_MINI_CORE | I2C_N_VAL_V2;
1125 
1126 	if (blk->is_tx_blk_mode)
1127 		writel(qup->config_run | blk->total_tx_len,
1128 		       qup->base + QUP_MX_OUTPUT_CNT);
1129 	else
1130 		writel(qup->config_run | blk->total_tx_len,
1131 		       qup->base + QUP_MX_WRITE_CNT);
1132 
1133 	if (blk->total_rx_len) {
1134 		if (blk->is_rx_blk_mode)
1135 			writel(qup->config_run | blk->total_rx_len,
1136 			       qup->base + QUP_MX_INPUT_CNT);
1137 		else
1138 			writel(qup->config_run | blk->total_rx_len,
1139 			       qup->base + QUP_MX_READ_CNT);
1140 	} else {
1141 		qup_config |= QUP_NO_INPUT;
1142 	}
1143 
1144 	writel(qup_config, qup->base + QUP_CONFIG);
1145 }
1146 
1147 /*
1148  * Configure registers related with transfer mode (FIFO/Block)
1149  * before starting of i2c transfer. It will be called only once in
1150  * QUP RESET state.
1151  */
qup_i2c_conf_mode_v2(struct qup_i2c_dev * qup)1152 static void qup_i2c_conf_mode_v2(struct qup_i2c_dev *qup)
1153 {
1154 	struct qup_i2c_block *blk = &qup->blk;
1155 	u32 io_mode = QUP_REPACK_EN;
1156 
1157 	if (blk->is_tx_blk_mode) {
1158 		io_mode |= QUP_OUTPUT_BLK_MODE;
1159 		writel(0, qup->base + QUP_MX_WRITE_CNT);
1160 	} else {
1161 		writel(0, qup->base + QUP_MX_OUTPUT_CNT);
1162 	}
1163 
1164 	if (blk->is_rx_blk_mode) {
1165 		io_mode |= QUP_INPUT_BLK_MODE;
1166 		writel(0, qup->base + QUP_MX_READ_CNT);
1167 	} else {
1168 		writel(0, qup->base + QUP_MX_INPUT_CNT);
1169 	}
1170 
1171 	writel(io_mode, qup->base + QUP_IO_MODE);
1172 }
1173 
1174 /* Clear required variables before starting of any QUP v2 sub transfer. */
qup_i2c_clear_blk_v2(struct qup_i2c_block * blk)1175 static void qup_i2c_clear_blk_v2(struct qup_i2c_block *blk)
1176 {
1177 	blk->send_last_word = false;
1178 	blk->tx_tags_sent = false;
1179 	blk->tx_fifo_data = 0;
1180 	blk->tx_fifo_data_pos = 0;
1181 	blk->tx_fifo_free = 0;
1182 
1183 	blk->rx_tags_fetched = false;
1184 	blk->rx_bytes_read = false;
1185 	blk->rx_fifo_data = 0;
1186 	blk->rx_fifo_data_pos = 0;
1187 	blk->fifo_available = 0;
1188 }
1189 
1190 /* Receive data from RX FIFO for read message in QUP v2 i2c transfer. */
qup_i2c_recv_data(struct qup_i2c_dev * qup)1191 static void qup_i2c_recv_data(struct qup_i2c_dev *qup)
1192 {
1193 	struct qup_i2c_block *blk = &qup->blk;
1194 	int j;
1195 
1196 	for (j = blk->rx_fifo_data_pos;
1197 	     blk->cur_blk_len && blk->fifo_available;
1198 	     blk->cur_blk_len--, blk->fifo_available--) {
1199 		if (j == 0)
1200 			blk->rx_fifo_data = readl(qup->base + QUP_IN_FIFO_BASE);
1201 
1202 		*(blk->cur_data++) = blk->rx_fifo_data;
1203 		blk->rx_fifo_data >>= 8;
1204 
1205 		if (j == 3)
1206 			j = 0;
1207 		else
1208 			j++;
1209 	}
1210 
1211 	blk->rx_fifo_data_pos = j;
1212 }
1213 
1214 /* Receive tags for read message in QUP v2 i2c transfer. */
qup_i2c_recv_tags(struct qup_i2c_dev * qup)1215 static void qup_i2c_recv_tags(struct qup_i2c_dev *qup)
1216 {
1217 	struct qup_i2c_block *blk = &qup->blk;
1218 
1219 	blk->rx_fifo_data = readl(qup->base + QUP_IN_FIFO_BASE);
1220 	blk->rx_fifo_data >>= blk->rx_tag_len  * 8;
1221 	blk->rx_fifo_data_pos = blk->rx_tag_len;
1222 	blk->fifo_available -= blk->rx_tag_len;
1223 }
1224 
1225 /*
1226  * Read the data and tags from RX FIFO. Since in read case, the tags will be
1227  * preceded by received data bytes so
1228  * 1. Check if rx_tags_fetched is false i.e. the start of QUP block so receive
1229  *    all tag bytes and discard that.
1230  * 2. Read the data from RX FIFO. When all the data bytes have been read then
1231  *    set rx_bytes_read to true.
1232  */
qup_i2c_read_rx_fifo_v2(struct qup_i2c_dev * qup)1233 static void qup_i2c_read_rx_fifo_v2(struct qup_i2c_dev *qup)
1234 {
1235 	struct qup_i2c_block *blk = &qup->blk;
1236 
1237 	if (!blk->rx_tags_fetched) {
1238 		qup_i2c_recv_tags(qup);
1239 		blk->rx_tags_fetched = true;
1240 	}
1241 
1242 	qup_i2c_recv_data(qup);
1243 	if (!blk->cur_blk_len)
1244 		blk->rx_bytes_read = true;
1245 }
1246 
1247 /*
1248  * Write bytes in TX FIFO for write message in QUP v2 i2c transfer. QUP TX FIFO
1249  * write works on word basis (4 bytes). Append new data byte write for TX FIFO
1250  * in tx_fifo_data and write to TX FIFO when all the 4 bytes are present.
1251  */
1252 static void
qup_i2c_write_blk_data(struct qup_i2c_dev * qup,u8 ** data,unsigned int * len)1253 qup_i2c_write_blk_data(struct qup_i2c_dev *qup, u8 **data, unsigned int *len)
1254 {
1255 	struct qup_i2c_block *blk = &qup->blk;
1256 	unsigned int j;
1257 
1258 	for (j = blk->tx_fifo_data_pos; *len && blk->tx_fifo_free;
1259 	     (*len)--, blk->tx_fifo_free--) {
1260 		blk->tx_fifo_data |= *(*data)++ << (j * 8);
1261 		if (j == 3) {
1262 			writel(blk->tx_fifo_data,
1263 			       qup->base + QUP_OUT_FIFO_BASE);
1264 			blk->tx_fifo_data = 0x0;
1265 			j = 0;
1266 		} else {
1267 			j++;
1268 		}
1269 	}
1270 
1271 	blk->tx_fifo_data_pos = j;
1272 }
1273 
1274 /* Transfer tags for read message in QUP v2 i2c transfer. */
qup_i2c_write_rx_tags_v2(struct qup_i2c_dev * qup)1275 static void qup_i2c_write_rx_tags_v2(struct qup_i2c_dev *qup)
1276 {
1277 	struct qup_i2c_block *blk = &qup->blk;
1278 
1279 	qup_i2c_write_blk_data(qup, &blk->cur_tx_tags, &blk->tx_tag_len);
1280 	if (blk->tx_fifo_data_pos)
1281 		writel(blk->tx_fifo_data, qup->base + QUP_OUT_FIFO_BASE);
1282 }
1283 
1284 /*
1285  * Write the data and tags in TX FIFO. Since in write case, both tags and data
1286  * need to be written and QUP write tags can have maximum 256 data length, so
1287  *
1288  * 1. Check if tx_tags_sent is false i.e. the start of QUP block so write the
1289  *    tags to TX FIFO and set tx_tags_sent to true.
1290  * 2. Check if send_last_word is true. It will be set when last few data bytes
1291  *    (less than 4 bytes) are remaining to be written in FIFO because of no FIFO
1292  *    space. All this data bytes are available in tx_fifo_data so write this
1293  *    in FIFO.
1294  * 3. Write the data to TX FIFO and check for cur_blk_len. If it is non zero
1295  *    then more data is pending otherwise following 3 cases can be possible
1296  *    a. if tx_fifo_data_pos is zero i.e. all the data bytes in this block
1297  *       have been written in TX FIFO so nothing else is required.
1298  *    b. tx_fifo_free is non zero i.e tx FIFO is free so copy the remaining data
1299  *       from tx_fifo_data to tx FIFO. Since, qup_i2c_write_blk_data do write
1300  *	 in 4 bytes and FIFO space is in multiple of 4 bytes so tx_fifo_free
1301  *       will be always greater than or equal to 4 bytes.
1302  *    c. tx_fifo_free is zero. In this case, last few bytes (less than 4
1303  *       bytes) are copied to tx_fifo_data but couldn't be sent because of
1304  *       FIFO full so make send_last_word true.
1305  */
qup_i2c_write_tx_fifo_v2(struct qup_i2c_dev * qup)1306 static void qup_i2c_write_tx_fifo_v2(struct qup_i2c_dev *qup)
1307 {
1308 	struct qup_i2c_block *blk = &qup->blk;
1309 
1310 	if (!blk->tx_tags_sent) {
1311 		qup_i2c_write_blk_data(qup, &blk->cur_tx_tags,
1312 				       &blk->tx_tag_len);
1313 		blk->tx_tags_sent = true;
1314 	}
1315 
1316 	if (blk->send_last_word)
1317 		goto send_last_word;
1318 
1319 	qup_i2c_write_blk_data(qup, &blk->cur_data, &blk->cur_blk_len);
1320 	if (!blk->cur_blk_len) {
1321 		if (!blk->tx_fifo_data_pos)
1322 			return;
1323 
1324 		if (blk->tx_fifo_free)
1325 			goto send_last_word;
1326 
1327 		blk->send_last_word = true;
1328 	}
1329 
1330 	return;
1331 
1332 send_last_word:
1333 	writel(blk->tx_fifo_data, qup->base + QUP_OUT_FIFO_BASE);
1334 }
1335 
1336 /*
1337  * Main transfer function which read or write i2c data.
1338  * The QUP v2 supports reconfiguration during run in which multiple i2c sub
1339  * transfers can be scheduled.
1340  */
1341 static int
qup_i2c_conf_xfer_v2(struct qup_i2c_dev * qup,bool is_rx,bool is_first,bool change_pause_state)1342 qup_i2c_conf_xfer_v2(struct qup_i2c_dev *qup, bool is_rx, bool is_first,
1343 		     bool change_pause_state)
1344 {
1345 	struct qup_i2c_block *blk = &qup->blk;
1346 	struct i2c_msg *msg = qup->msg;
1347 	int ret;
1348 
1349 	/*
1350 	 * Check if its SMBus Block read for which the top level read will be
1351 	 * done into 2 QUP reads. One with message length 1 while other one is
1352 	 * with actual length.
1353 	 */
1354 	if (qup_i2c_check_msg_len(msg)) {
1355 		if (qup->is_smbus_read) {
1356 			/*
1357 			 * If the message length is already read in
1358 			 * the first byte of the buffer, account for
1359 			 * that by setting the offset
1360 			 */
1361 			blk->cur_data += 1;
1362 			is_first = false;
1363 		} else {
1364 			change_pause_state = false;
1365 		}
1366 	}
1367 
1368 	qup->config_run = is_first ? 0 : QUP_I2C_MX_CONFIG_DURING_RUN;
1369 
1370 	qup_i2c_clear_blk_v2(blk);
1371 	qup_i2c_conf_count_v2(qup);
1372 
1373 	/* If it is first sub transfer, then configure i2c bus clocks */
1374 	if (is_first) {
1375 		ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
1376 		if (ret)
1377 			return ret;
1378 
1379 		writel(qup->clk_ctl, qup->base + QUP_I2C_CLK_CTL);
1380 
1381 		ret = qup_i2c_change_state(qup, QUP_PAUSE_STATE);
1382 		if (ret)
1383 			return ret;
1384 	}
1385 
1386 	reinit_completion(&qup->xfer);
1387 	enable_irq(qup->irq);
1388 	/*
1389 	 * In FIFO mode, tx FIFO can be written directly while in block mode the
1390 	 * it will be written after getting OUT_BLOCK_WRITE_REQ interrupt
1391 	 */
1392 	if (!blk->is_tx_blk_mode) {
1393 		blk->tx_fifo_free = qup->out_fifo_sz;
1394 
1395 		if (is_rx)
1396 			qup_i2c_write_rx_tags_v2(qup);
1397 		else
1398 			qup_i2c_write_tx_fifo_v2(qup);
1399 	}
1400 
1401 	ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
1402 	if (ret)
1403 		goto err;
1404 
1405 	ret = qup_i2c_wait_for_complete(qup, msg);
1406 	if (ret)
1407 		goto err;
1408 
1409 	/* Move to pause state for all the transfers, except last one */
1410 	if (change_pause_state) {
1411 		ret = qup_i2c_change_state(qup, QUP_PAUSE_STATE);
1412 		if (ret)
1413 			goto err;
1414 	}
1415 
1416 err:
1417 	disable_irq(qup->irq);
1418 	return ret;
1419 }
1420 
1421 /*
1422  * Transfer one read/write message in i2c transfer. It splits the message into
1423  * multiple of blk_xfer_limit data length blocks and schedule each
1424  * QUP block individually.
1425  */
qup_i2c_xfer_v2_msg(struct qup_i2c_dev * qup,int msg_id,bool is_rx)1426 static int qup_i2c_xfer_v2_msg(struct qup_i2c_dev *qup, int msg_id, bool is_rx)
1427 {
1428 	int ret = 0;
1429 	unsigned int data_len, i;
1430 	struct i2c_msg *msg = qup->msg;
1431 	struct qup_i2c_block *blk = &qup->blk;
1432 	u8 *msg_buf = msg->buf;
1433 
1434 	qup->blk_xfer_limit = is_rx ? RECV_MAX_DATA_LEN : QUP_READ_LIMIT;
1435 	qup_i2c_set_blk_data(qup, msg);
1436 
1437 	for (i = 0; i < blk->count; i++) {
1438 		data_len =  qup_i2c_get_data_len(qup);
1439 		blk->pos = i;
1440 		blk->cur_tx_tags = blk->tags;
1441 		blk->cur_blk_len = data_len;
1442 		blk->tx_tag_len =
1443 			qup_i2c_set_tags(blk->cur_tx_tags, qup, qup->msg);
1444 
1445 		blk->cur_data = msg_buf;
1446 
1447 		if (is_rx) {
1448 			blk->total_tx_len = blk->tx_tag_len;
1449 			blk->rx_tag_len = 2;
1450 			blk->total_rx_len = blk->rx_tag_len + data_len;
1451 		} else {
1452 			blk->total_tx_len = blk->tx_tag_len + data_len;
1453 			blk->total_rx_len = 0;
1454 		}
1455 
1456 		ret = qup_i2c_conf_xfer_v2(qup, is_rx, !msg_id && !i,
1457 					   !qup->is_last || i < blk->count - 1);
1458 		if (ret)
1459 			return ret;
1460 
1461 		/* Handle SMBus block read length */
1462 		if (qup_i2c_check_msg_len(msg) && msg->len == 1 &&
1463 		    !qup->is_smbus_read) {
1464 			if (msg->buf[0] > I2C_SMBUS_BLOCK_MAX)
1465 				return -EPROTO;
1466 
1467 			msg->len = msg->buf[0];
1468 			qup->is_smbus_read = true;
1469 			ret = qup_i2c_xfer_v2_msg(qup, msg_id, true);
1470 			qup->is_smbus_read = false;
1471 			if (ret)
1472 				return ret;
1473 
1474 			msg->len += 1;
1475 		}
1476 
1477 		msg_buf += data_len;
1478 		blk->data_len -= qup->blk_xfer_limit;
1479 	}
1480 
1481 	return ret;
1482 }
1483 
1484 /*
1485  * QUP v2 supports 3 modes
1486  * Programmed IO using FIFO mode : Less than FIFO size
1487  * Programmed IO using Block mode : Greater than FIFO size
1488  * DMA using BAM : Appropriate for any transaction size but the address should
1489  *		   be DMA applicable
1490  *
1491  * This function determines the mode which will be used for this transfer. An
1492  * i2c transfer contains multiple message. Following are the rules to determine
1493  * the mode used.
1494  * 1. Determine complete length, maximum tx and rx length for complete transfer.
1495  * 2. If complete transfer length is greater than fifo size then use the DMA
1496  *    mode.
1497  * 3. In FIFO or block mode, tx and rx can operate in different mode so check
1498  *    for maximum tx and rx length to determine mode.
1499  */
1500 static int
qup_i2c_determine_mode_v2(struct qup_i2c_dev * qup,struct i2c_msg msgs[],int num)1501 qup_i2c_determine_mode_v2(struct qup_i2c_dev *qup,
1502 			  struct i2c_msg msgs[], int num)
1503 {
1504 	int idx;
1505 	bool no_dma = false;
1506 	unsigned int max_tx_len = 0, max_rx_len = 0, total_len = 0;
1507 
1508 	/* All i2c_msgs should be transferred using either dma or cpu */
1509 	for (idx = 0; idx < num; idx++) {
1510 		if (msgs[idx].flags & I2C_M_RD)
1511 			max_rx_len = max_t(unsigned int, max_rx_len,
1512 					   msgs[idx].len);
1513 		else
1514 			max_tx_len = max_t(unsigned int, max_tx_len,
1515 					   msgs[idx].len);
1516 
1517 		if (is_vmalloc_addr(msgs[idx].buf))
1518 			no_dma = true;
1519 
1520 		total_len += msgs[idx].len;
1521 	}
1522 
1523 	if (!no_dma && qup->is_dma &&
1524 	    (total_len > qup->out_fifo_sz || total_len > qup->in_fifo_sz)) {
1525 		qup->use_dma = true;
1526 	} else {
1527 		qup->blk.is_tx_blk_mode = max_tx_len > qup->out_fifo_sz -
1528 			QUP_MAX_TAGS_LEN;
1529 		qup->blk.is_rx_blk_mode = max_rx_len > qup->in_fifo_sz -
1530 			READ_RX_TAGS_LEN;
1531 	}
1532 
1533 	return 0;
1534 }
1535 
qup_i2c_xfer_v2(struct i2c_adapter * adap,struct i2c_msg msgs[],int num)1536 static int qup_i2c_xfer_v2(struct i2c_adapter *adap,
1537 			   struct i2c_msg msgs[],
1538 			   int num)
1539 {
1540 	struct qup_i2c_dev *qup = i2c_get_adapdata(adap);
1541 	int ret, idx = 0;
1542 
1543 	qup->bus_err = 0;
1544 	qup->qup_err = 0;
1545 
1546 	ret = pm_runtime_get_sync(qup->dev);
1547 	if (ret < 0)
1548 		goto out;
1549 
1550 	ret = qup_i2c_determine_mode_v2(qup, msgs, num);
1551 	if (ret)
1552 		goto out;
1553 
1554 	writel(1, qup->base + QUP_SW_RESET);
1555 	ret = qup_i2c_poll_state(qup, QUP_RESET_STATE);
1556 	if (ret)
1557 		goto out;
1558 
1559 	/* Configure QUP as I2C mini core */
1560 	writel(I2C_MINI_CORE | I2C_N_VAL_V2, qup->base + QUP_CONFIG);
1561 	writel(QUP_V2_TAGS_EN, qup->base + QUP_I2C_MASTER_GEN);
1562 
1563 	if (qup_i2c_poll_state_i2c_master(qup)) {
1564 		ret = -EIO;
1565 		goto out;
1566 	}
1567 
1568 	if (qup->use_dma) {
1569 		reinit_completion(&qup->xfer);
1570 		ret = qup_i2c_bam_xfer(adap, &msgs[0], num);
1571 		qup->use_dma = false;
1572 	} else {
1573 		qup_i2c_conf_mode_v2(qup);
1574 
1575 		for (idx = 0; idx < num; idx++) {
1576 			qup->msg = &msgs[idx];
1577 			qup->is_last = idx == (num - 1);
1578 
1579 			ret = qup_i2c_xfer_v2_msg(qup, idx,
1580 					!!(msgs[idx].flags & I2C_M_RD));
1581 			if (ret)
1582 				break;
1583 		}
1584 		qup->msg = NULL;
1585 	}
1586 
1587 	if (!ret)
1588 		ret = qup_i2c_bus_active(qup, ONE_BYTE);
1589 
1590 	if (!ret)
1591 		qup_i2c_change_state(qup, QUP_RESET_STATE);
1592 
1593 	if (ret == 0)
1594 		ret = num;
1595 out:
1596 	pm_runtime_mark_last_busy(qup->dev);
1597 	pm_runtime_put_autosuspend(qup->dev);
1598 
1599 	return ret;
1600 }
1601 
qup_i2c_func(struct i2c_adapter * adap)1602 static u32 qup_i2c_func(struct i2c_adapter *adap)
1603 {
1604 	return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL_ALL & ~I2C_FUNC_SMBUS_QUICK);
1605 }
1606 
1607 static const struct i2c_algorithm qup_i2c_algo = {
1608 	.master_xfer	= qup_i2c_xfer,
1609 	.functionality	= qup_i2c_func,
1610 };
1611 
1612 static const struct i2c_algorithm qup_i2c_algo_v2 = {
1613 	.master_xfer	= qup_i2c_xfer_v2,
1614 	.functionality	= qup_i2c_func,
1615 };
1616 
1617 /*
1618  * The QUP block will issue a NACK and STOP on the bus when reaching
1619  * the end of the read, the length of the read is specified as one byte
1620  * which limits the possible read to 256 (QUP_READ_LIMIT) bytes.
1621  */
1622 static const struct i2c_adapter_quirks qup_i2c_quirks = {
1623 	.flags = I2C_AQ_NO_ZERO_LEN,
1624 	.max_read_len = QUP_READ_LIMIT,
1625 };
1626 
1627 static const struct i2c_adapter_quirks qup_i2c_quirks_v2 = {
1628 	.flags = I2C_AQ_NO_ZERO_LEN,
1629 };
1630 
qup_i2c_enable_clocks(struct qup_i2c_dev * qup)1631 static void qup_i2c_enable_clocks(struct qup_i2c_dev *qup)
1632 {
1633 	clk_prepare_enable(qup->clk);
1634 	clk_prepare_enable(qup->pclk);
1635 }
1636 
qup_i2c_disable_clocks(struct qup_i2c_dev * qup)1637 static void qup_i2c_disable_clocks(struct qup_i2c_dev *qup)
1638 {
1639 	u32 config;
1640 
1641 	qup_i2c_change_state(qup, QUP_RESET_STATE);
1642 	clk_disable_unprepare(qup->clk);
1643 	config = readl(qup->base + QUP_CONFIG);
1644 	config |= QUP_CLOCK_AUTO_GATE;
1645 	writel(config, qup->base + QUP_CONFIG);
1646 	clk_disable_unprepare(qup->pclk);
1647 }
1648 
1649 static const struct acpi_device_id qup_i2c_acpi_match[] = {
1650 	{ "QCOM8010"},
1651 	{ }
1652 };
1653 MODULE_DEVICE_TABLE(acpi, qup_i2c_acpi_match);
1654 
qup_i2c_probe(struct platform_device * pdev)1655 static int qup_i2c_probe(struct platform_device *pdev)
1656 {
1657 	static const int blk_sizes[] = {4, 16, 32};
1658 	struct qup_i2c_dev *qup;
1659 	unsigned long one_bit_t;
1660 	u32 io_mode, hw_ver, size;
1661 	int ret, fs_div, hs_div;
1662 	u32 src_clk_freq = DEFAULT_SRC_CLK;
1663 	u32 clk_freq = DEFAULT_CLK_FREQ;
1664 	int blocks;
1665 	bool is_qup_v1;
1666 
1667 	qup = devm_kzalloc(&pdev->dev, sizeof(*qup), GFP_KERNEL);
1668 	if (!qup)
1669 		return -ENOMEM;
1670 
1671 	qup->dev = &pdev->dev;
1672 	init_completion(&qup->xfer);
1673 	platform_set_drvdata(pdev, qup);
1674 
1675 	if (scl_freq) {
1676 		dev_notice(qup->dev, "Using override frequency of %u\n", scl_freq);
1677 		clk_freq = scl_freq;
1678 	} else {
1679 		ret = device_property_read_u32(qup->dev, "clock-frequency", &clk_freq);
1680 		if (ret) {
1681 			dev_notice(qup->dev, "using default clock-frequency %d",
1682 				DEFAULT_CLK_FREQ);
1683 		}
1684 	}
1685 
1686 	if (device_is_compatible(&pdev->dev, "qcom,i2c-qup-v1.1.1")) {
1687 		qup->adap.algo = &qup_i2c_algo;
1688 		qup->adap.quirks = &qup_i2c_quirks;
1689 		is_qup_v1 = true;
1690 	} else {
1691 		qup->adap.algo = &qup_i2c_algo_v2;
1692 		qup->adap.quirks = &qup_i2c_quirks_v2;
1693 		is_qup_v1 = false;
1694 		if (acpi_match_device(qup_i2c_acpi_match, qup->dev))
1695 			goto nodma;
1696 		else
1697 			ret = qup_i2c_req_dma(qup);
1698 
1699 		if (ret == -EPROBE_DEFER)
1700 			goto fail_dma;
1701 		else if (ret != 0)
1702 			goto nodma;
1703 
1704 		qup->max_xfer_sg_len = (MX_BLOCKS << 1);
1705 		blocks = (MX_DMA_BLOCKS << 1) + 1;
1706 		qup->btx.sg = devm_kcalloc(&pdev->dev,
1707 					   blocks, sizeof(*qup->btx.sg),
1708 					   GFP_KERNEL);
1709 		if (!qup->btx.sg) {
1710 			ret = -ENOMEM;
1711 			goto fail_dma;
1712 		}
1713 		sg_init_table(qup->btx.sg, blocks);
1714 
1715 		qup->brx.sg = devm_kcalloc(&pdev->dev,
1716 					   blocks, sizeof(*qup->brx.sg),
1717 					   GFP_KERNEL);
1718 		if (!qup->brx.sg) {
1719 			ret = -ENOMEM;
1720 			goto fail_dma;
1721 		}
1722 		sg_init_table(qup->brx.sg, blocks);
1723 
1724 		/* 2 tag bytes for each block + 5 for start, stop tags */
1725 		size = blocks * 2 + 5;
1726 
1727 		qup->start_tag.start = devm_kzalloc(&pdev->dev,
1728 						    size, GFP_KERNEL);
1729 		if (!qup->start_tag.start) {
1730 			ret = -ENOMEM;
1731 			goto fail_dma;
1732 		}
1733 
1734 		qup->brx.tag.start = devm_kzalloc(&pdev->dev, 2, GFP_KERNEL);
1735 		if (!qup->brx.tag.start) {
1736 			ret = -ENOMEM;
1737 			goto fail_dma;
1738 		}
1739 
1740 		qup->btx.tag.start = devm_kzalloc(&pdev->dev, 2, GFP_KERNEL);
1741 		if (!qup->btx.tag.start) {
1742 			ret = -ENOMEM;
1743 			goto fail_dma;
1744 		}
1745 		qup->is_dma = true;
1746 	}
1747 
1748 nodma:
1749 	/* We support frequencies up to FAST Mode Plus (1MHz) */
1750 	if (!clk_freq || clk_freq > I2C_MAX_FAST_MODE_PLUS_FREQ) {
1751 		dev_err(qup->dev, "clock frequency not supported %d\n",
1752 			clk_freq);
1753 		ret = -EINVAL;
1754 		goto fail_dma;
1755 	}
1756 
1757 	qup->base = devm_platform_ioremap_resource(pdev, 0);
1758 	if (IS_ERR(qup->base)) {
1759 		ret = PTR_ERR(qup->base);
1760 		goto fail_dma;
1761 	}
1762 
1763 	qup->irq = platform_get_irq(pdev, 0);
1764 	if (qup->irq < 0) {
1765 		ret = qup->irq;
1766 		goto fail_dma;
1767 	}
1768 
1769 	if (has_acpi_companion(qup->dev)) {
1770 		ret = device_property_read_u32(qup->dev,
1771 				"src-clock-hz", &src_clk_freq);
1772 		if (ret) {
1773 			dev_notice(qup->dev, "using default src-clock-hz %d",
1774 				DEFAULT_SRC_CLK);
1775 		}
1776 		ACPI_COMPANION_SET(&qup->adap.dev, ACPI_COMPANION(qup->dev));
1777 	} else {
1778 		qup->clk = devm_clk_get(qup->dev, "core");
1779 		if (IS_ERR(qup->clk)) {
1780 			dev_err(qup->dev, "Could not get core clock\n");
1781 			ret = PTR_ERR(qup->clk);
1782 			goto fail_dma;
1783 		}
1784 
1785 		qup->pclk = devm_clk_get(qup->dev, "iface");
1786 		if (IS_ERR(qup->pclk)) {
1787 			dev_err(qup->dev, "Could not get iface clock\n");
1788 			ret = PTR_ERR(qup->pclk);
1789 			goto fail_dma;
1790 		}
1791 		qup_i2c_enable_clocks(qup);
1792 		src_clk_freq = clk_get_rate(qup->clk);
1793 	}
1794 
1795 	/*
1796 	 * Bootloaders might leave a pending interrupt on certain QUP's,
1797 	 * so we reset the core before registering for interrupts.
1798 	 */
1799 	writel(1, qup->base + QUP_SW_RESET);
1800 	ret = qup_i2c_poll_state_valid(qup);
1801 	if (ret)
1802 		goto fail;
1803 
1804 	ret = devm_request_irq(qup->dev, qup->irq, qup_i2c_interrupt,
1805 			       IRQF_TRIGGER_HIGH | IRQF_NO_AUTOEN,
1806 			       "i2c_qup", qup);
1807 	if (ret) {
1808 		dev_err(qup->dev, "Request %d IRQ failed\n", qup->irq);
1809 		goto fail;
1810 	}
1811 
1812 	hw_ver = readl(qup->base + QUP_HW_VERSION);
1813 	dev_dbg(qup->dev, "Revision %x\n", hw_ver);
1814 
1815 	io_mode = readl(qup->base + QUP_IO_MODE);
1816 
1817 	/*
1818 	 * The block/fifo size w.r.t. 'actual data' is 1/2 due to 'tag'
1819 	 * associated with each byte written/received
1820 	 */
1821 	size = QUP_OUTPUT_BLOCK_SIZE(io_mode);
1822 	if (size >= ARRAY_SIZE(blk_sizes)) {
1823 		ret = -EIO;
1824 		goto fail;
1825 	}
1826 	qup->out_blk_sz = blk_sizes[size];
1827 
1828 	size = QUP_INPUT_BLOCK_SIZE(io_mode);
1829 	if (size >= ARRAY_SIZE(blk_sizes)) {
1830 		ret = -EIO;
1831 		goto fail;
1832 	}
1833 	qup->in_blk_sz = blk_sizes[size];
1834 
1835 	if (is_qup_v1) {
1836 		/*
1837 		 * in QUP v1, QUP_CONFIG uses N as 15 i.e 16 bits constitutes a
1838 		 * single transfer but the block size is in bytes so divide the
1839 		 * in_blk_sz and out_blk_sz by 2
1840 		 */
1841 		qup->in_blk_sz /= 2;
1842 		qup->out_blk_sz /= 2;
1843 		qup->write_tx_fifo = qup_i2c_write_tx_fifo_v1;
1844 		qup->read_rx_fifo = qup_i2c_read_rx_fifo_v1;
1845 		qup->write_rx_tags = qup_i2c_write_rx_tags_v1;
1846 	} else {
1847 		qup->write_tx_fifo = qup_i2c_write_tx_fifo_v2;
1848 		qup->read_rx_fifo = qup_i2c_read_rx_fifo_v2;
1849 		qup->write_rx_tags = qup_i2c_write_rx_tags_v2;
1850 	}
1851 
1852 	size = QUP_OUTPUT_FIFO_SIZE(io_mode);
1853 	qup->out_fifo_sz = qup->out_blk_sz * (2 << size);
1854 
1855 	size = QUP_INPUT_FIFO_SIZE(io_mode);
1856 	qup->in_fifo_sz = qup->in_blk_sz * (2 << size);
1857 
1858 	hs_div = 3;
1859 	if (clk_freq <= I2C_MAX_STANDARD_MODE_FREQ) {
1860 		fs_div = ((src_clk_freq / clk_freq) / 2) - 3;
1861 		qup->clk_ctl = (hs_div << 8) | (fs_div & 0xff);
1862 	} else {
1863 		/* 33%/66% duty cycle */
1864 		fs_div = ((src_clk_freq / clk_freq) - 6) * 2 / 3;
1865 		qup->clk_ctl = ((fs_div / 2) << 16) | (hs_div << 8) | (fs_div & 0xff);
1866 	}
1867 
1868 	/*
1869 	 * Time it takes for a byte to be clocked out on the bus.
1870 	 * Each byte takes 9 clock cycles (8 bits + 1 ack).
1871 	 */
1872 	one_bit_t = (USEC_PER_SEC / clk_freq) + 1;
1873 	qup->one_byte_t = one_bit_t * 9;
1874 	qup->xfer_timeout = TOUT_MIN * HZ +
1875 		usecs_to_jiffies(MX_DMA_TX_RX_LEN * qup->one_byte_t);
1876 
1877 	dev_dbg(qup->dev, "IN:block:%d, fifo:%d, OUT:block:%d, fifo:%d\n",
1878 		qup->in_blk_sz, qup->in_fifo_sz,
1879 		qup->out_blk_sz, qup->out_fifo_sz);
1880 
1881 	i2c_set_adapdata(&qup->adap, qup);
1882 	qup->adap.dev.parent = qup->dev;
1883 	qup->adap.dev.of_node = pdev->dev.of_node;
1884 	qup->is_last = true;
1885 
1886 	strscpy(qup->adap.name, "QUP I2C adapter", sizeof(qup->adap.name));
1887 
1888 	pm_runtime_set_autosuspend_delay(qup->dev, MSEC_PER_SEC);
1889 	pm_runtime_use_autosuspend(qup->dev);
1890 	pm_runtime_set_active(qup->dev);
1891 	pm_runtime_enable(qup->dev);
1892 
1893 	ret = i2c_add_adapter(&qup->adap);
1894 	if (ret)
1895 		goto fail_runtime;
1896 
1897 	return 0;
1898 
1899 fail_runtime:
1900 	pm_runtime_disable(qup->dev);
1901 	pm_runtime_set_suspended(qup->dev);
1902 fail:
1903 	qup_i2c_disable_clocks(qup);
1904 fail_dma:
1905 	if (qup->btx.dma)
1906 		dma_release_channel(qup->btx.dma);
1907 	if (qup->brx.dma)
1908 		dma_release_channel(qup->brx.dma);
1909 	return ret;
1910 }
1911 
qup_i2c_remove(struct platform_device * pdev)1912 static void qup_i2c_remove(struct platform_device *pdev)
1913 {
1914 	struct qup_i2c_dev *qup = platform_get_drvdata(pdev);
1915 
1916 	if (qup->is_dma) {
1917 		dma_release_channel(qup->btx.dma);
1918 		dma_release_channel(qup->brx.dma);
1919 	}
1920 
1921 	disable_irq(qup->irq);
1922 	qup_i2c_disable_clocks(qup);
1923 	i2c_del_adapter(&qup->adap);
1924 	pm_runtime_disable(qup->dev);
1925 	pm_runtime_set_suspended(qup->dev);
1926 }
1927 
qup_i2c_pm_suspend_runtime(struct device * device)1928 static int qup_i2c_pm_suspend_runtime(struct device *device)
1929 {
1930 	struct qup_i2c_dev *qup = dev_get_drvdata(device);
1931 
1932 	dev_dbg(device, "pm_runtime: suspending...\n");
1933 	qup_i2c_disable_clocks(qup);
1934 	return 0;
1935 }
1936 
qup_i2c_pm_resume_runtime(struct device * device)1937 static int qup_i2c_pm_resume_runtime(struct device *device)
1938 {
1939 	struct qup_i2c_dev *qup = dev_get_drvdata(device);
1940 
1941 	dev_dbg(device, "pm_runtime: resuming...\n");
1942 	qup_i2c_enable_clocks(qup);
1943 	return 0;
1944 }
1945 
qup_i2c_suspend(struct device * device)1946 static int qup_i2c_suspend(struct device *device)
1947 {
1948 	if (!pm_runtime_suspended(device))
1949 		return qup_i2c_pm_suspend_runtime(device);
1950 	return 0;
1951 }
1952 
qup_i2c_resume(struct device * device)1953 static int qup_i2c_resume(struct device *device)
1954 {
1955 	qup_i2c_pm_resume_runtime(device);
1956 	pm_runtime_mark_last_busy(device);
1957 	pm_request_autosuspend(device);
1958 	return 0;
1959 }
1960 
1961 static const struct dev_pm_ops qup_i2c_qup_pm_ops = {
1962 	SYSTEM_SLEEP_PM_OPS(qup_i2c_suspend, qup_i2c_resume)
1963 	RUNTIME_PM_OPS(qup_i2c_pm_suspend_runtime,
1964 		       qup_i2c_pm_resume_runtime, NULL)
1965 };
1966 
1967 static const struct of_device_id qup_i2c_dt_match[] = {
1968 	{ .compatible = "qcom,i2c-qup-v1.1.1" },
1969 	{ .compatible = "qcom,i2c-qup-v2.1.1" },
1970 	{ .compatible = "qcom,i2c-qup-v2.2.1" },
1971 	{}
1972 };
1973 MODULE_DEVICE_TABLE(of, qup_i2c_dt_match);
1974 
1975 static struct platform_driver qup_i2c_driver = {
1976 	.probe  = qup_i2c_probe,
1977 	.remove = qup_i2c_remove,
1978 	.driver = {
1979 		.name = "i2c_qup",
1980 		.pm = pm_ptr(&qup_i2c_qup_pm_ops),
1981 		.of_match_table = qup_i2c_dt_match,
1982 		.acpi_match_table = ACPI_PTR(qup_i2c_acpi_match),
1983 	},
1984 };
1985 
1986 module_platform_driver(qup_i2c_driver);
1987 
1988 MODULE_DESCRIPTION("Qualcomm QUP based I2C controller");
1989 MODULE_LICENSE("GPL v2");
1990 MODULE_ALIAS("platform:i2c_qup");
1991