xref: /openbmc/linux/drivers/i2c/busses/i2c-qup.c (revision d19941ac)
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/of.h>
21 #include <linux/platform_device.h>
22 #include <linux/pm_runtime.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 		dev_err(qup->dev, "normal trans timed out\n");
798 		ret = -ETIMEDOUT;
799 	}
800 
801 	if (ret || qup->bus_err || qup->qup_err) {
802 		reinit_completion(&qup->xfer);
803 
804 		ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
805 		if (ret) {
806 			dev_err(qup->dev, "change to run state timed out");
807 			goto desc_err;
808 		}
809 
810 		qup_i2c_flush(qup);
811 
812 		/* wait for remaining interrupts to occur */
813 		if (!wait_for_completion_timeout(&qup->xfer, HZ))
814 			dev_err(qup->dev, "flush timed out\n");
815 
816 		ret =  (qup->bus_err & QUP_I2C_NACK_FLAG) ? -ENXIO : -EIO;
817 	}
818 
819 desc_err:
820 	dma_unmap_sg(qup->dev, qup->btx.sg, tx_cnt, DMA_TO_DEVICE);
821 
822 	if (rx_cnt)
823 		dma_unmap_sg(qup->dev, qup->brx.sg, rx_cnt,
824 			     DMA_FROM_DEVICE);
825 
826 	return ret;
827 }
828 
qup_i2c_bam_clear_tag_buffers(struct qup_i2c_dev * qup)829 static void qup_i2c_bam_clear_tag_buffers(struct qup_i2c_dev *qup)
830 {
831 	qup->btx.sg_cnt = 0;
832 	qup->brx.sg_cnt = 0;
833 	qup->tag_buf_pos = 0;
834 }
835 
qup_i2c_bam_xfer(struct i2c_adapter * adap,struct i2c_msg * msg,int num)836 static int qup_i2c_bam_xfer(struct i2c_adapter *adap, struct i2c_msg *msg,
837 			    int num)
838 {
839 	struct qup_i2c_dev *qup = i2c_get_adapdata(adap);
840 	int ret = 0;
841 	int idx = 0;
842 
843 	enable_irq(qup->irq);
844 	ret = qup_i2c_req_dma(qup);
845 
846 	if (ret)
847 		goto out;
848 
849 	writel(0, qup->base + QUP_MX_INPUT_CNT);
850 	writel(0, qup->base + QUP_MX_OUTPUT_CNT);
851 
852 	/* set BAM mode */
853 	writel(QUP_REPACK_EN | QUP_BAM_MODE, qup->base + QUP_IO_MODE);
854 
855 	/* mask fifo irqs */
856 	writel((0x3 << 8), qup->base + QUP_OPERATIONAL_MASK);
857 
858 	/* set RUN STATE */
859 	ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
860 	if (ret)
861 		goto out;
862 
863 	writel(qup->clk_ctl, qup->base + QUP_I2C_CLK_CTL);
864 	qup_i2c_bam_clear_tag_buffers(qup);
865 
866 	for (idx = 0; idx < num; idx++) {
867 		qup->msg = msg + idx;
868 		qup->is_last = idx == (num - 1);
869 
870 		ret = qup_i2c_bam_make_desc(qup, qup->msg);
871 		if (ret)
872 			break;
873 
874 		/*
875 		 * Make DMA descriptor and schedule the BAM transfer if its
876 		 * already crossed the maximum length. Since the memory for all
877 		 * tags buffers have been taken for 2 maximum possible
878 		 * transfers length so it will never cross the buffer actual
879 		 * length.
880 		 */
881 		if (qup->btx.sg_cnt > qup->max_xfer_sg_len ||
882 		    qup->brx.sg_cnt > qup->max_xfer_sg_len ||
883 		    qup->is_last) {
884 			ret = qup_i2c_bam_schedule_desc(qup);
885 			if (ret)
886 				break;
887 
888 			qup_i2c_bam_clear_tag_buffers(qup);
889 		}
890 	}
891 
892 out:
893 	disable_irq(qup->irq);
894 
895 	qup->msg = NULL;
896 	return ret;
897 }
898 
qup_i2c_wait_for_complete(struct qup_i2c_dev * qup,struct i2c_msg * msg)899 static int qup_i2c_wait_for_complete(struct qup_i2c_dev *qup,
900 				     struct i2c_msg *msg)
901 {
902 	unsigned long left;
903 	int ret = 0;
904 
905 	left = wait_for_completion_timeout(&qup->xfer, qup->xfer_timeout);
906 	if (!left) {
907 		writel(1, qup->base + QUP_SW_RESET);
908 		ret = -ETIMEDOUT;
909 	}
910 
911 	if (qup->bus_err || qup->qup_err)
912 		ret =  (qup->bus_err & QUP_I2C_NACK_FLAG) ? -ENXIO : -EIO;
913 
914 	return ret;
915 }
916 
qup_i2c_read_rx_fifo_v1(struct qup_i2c_dev * qup)917 static void qup_i2c_read_rx_fifo_v1(struct qup_i2c_dev *qup)
918 {
919 	struct qup_i2c_block *blk = &qup->blk;
920 	struct i2c_msg *msg = qup->msg;
921 	u32 val = 0;
922 	int idx = 0;
923 
924 	while (blk->fifo_available && qup->pos < msg->len) {
925 		if ((idx & 1) == 0) {
926 			/* Reading 2 words at time */
927 			val = readl(qup->base + QUP_IN_FIFO_BASE);
928 			msg->buf[qup->pos++] = val & 0xFF;
929 		} else {
930 			msg->buf[qup->pos++] = val >> QUP_MSW_SHIFT;
931 		}
932 		idx++;
933 		blk->fifo_available--;
934 	}
935 
936 	if (qup->pos == msg->len)
937 		blk->rx_bytes_read = true;
938 }
939 
qup_i2c_write_rx_tags_v1(struct qup_i2c_dev * qup)940 static void qup_i2c_write_rx_tags_v1(struct qup_i2c_dev *qup)
941 {
942 	struct i2c_msg *msg = qup->msg;
943 	u32 addr, len, val;
944 
945 	addr = i2c_8bit_addr_from_msg(msg);
946 
947 	/* 0 is used to specify a length 256 (QUP_READ_LIMIT) */
948 	len = (msg->len == QUP_READ_LIMIT) ? 0 : msg->len;
949 
950 	val = ((QUP_TAG_REC | len) << QUP_MSW_SHIFT) | QUP_TAG_START | addr;
951 	writel(val, qup->base + QUP_OUT_FIFO_BASE);
952 }
953 
qup_i2c_conf_v1(struct qup_i2c_dev * qup)954 static void qup_i2c_conf_v1(struct qup_i2c_dev *qup)
955 {
956 	struct qup_i2c_block *blk = &qup->blk;
957 	u32 qup_config = I2C_MINI_CORE | I2C_N_VAL;
958 	u32 io_mode = QUP_REPACK_EN;
959 
960 	blk->is_tx_blk_mode = blk->total_tx_len > qup->out_fifo_sz;
961 	blk->is_rx_blk_mode = blk->total_rx_len > qup->in_fifo_sz;
962 
963 	if (blk->is_tx_blk_mode) {
964 		io_mode |= QUP_OUTPUT_BLK_MODE;
965 		writel(0, qup->base + QUP_MX_WRITE_CNT);
966 		writel(blk->total_tx_len, qup->base + QUP_MX_OUTPUT_CNT);
967 	} else {
968 		writel(0, qup->base + QUP_MX_OUTPUT_CNT);
969 		writel(blk->total_tx_len, qup->base + QUP_MX_WRITE_CNT);
970 	}
971 
972 	if (blk->total_rx_len) {
973 		if (blk->is_rx_blk_mode) {
974 			io_mode |= QUP_INPUT_BLK_MODE;
975 			writel(0, qup->base + QUP_MX_READ_CNT);
976 			writel(blk->total_rx_len, qup->base + QUP_MX_INPUT_CNT);
977 		} else {
978 			writel(0, qup->base + QUP_MX_INPUT_CNT);
979 			writel(blk->total_rx_len, qup->base + QUP_MX_READ_CNT);
980 		}
981 	} else {
982 		qup_config |= QUP_NO_INPUT;
983 	}
984 
985 	writel(qup_config, qup->base + QUP_CONFIG);
986 	writel(io_mode, qup->base + QUP_IO_MODE);
987 }
988 
qup_i2c_clear_blk_v1(struct qup_i2c_block * blk)989 static void qup_i2c_clear_blk_v1(struct qup_i2c_block *blk)
990 {
991 	blk->tx_fifo_free = 0;
992 	blk->fifo_available = 0;
993 	blk->rx_bytes_read = false;
994 }
995 
qup_i2c_conf_xfer_v1(struct qup_i2c_dev * qup,bool is_rx)996 static int qup_i2c_conf_xfer_v1(struct qup_i2c_dev *qup, bool is_rx)
997 {
998 	struct qup_i2c_block *blk = &qup->blk;
999 	int ret;
1000 
1001 	qup_i2c_clear_blk_v1(blk);
1002 	qup_i2c_conf_v1(qup);
1003 	ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
1004 	if (ret)
1005 		return ret;
1006 
1007 	writel(qup->clk_ctl, qup->base + QUP_I2C_CLK_CTL);
1008 
1009 	ret = qup_i2c_change_state(qup, QUP_PAUSE_STATE);
1010 	if (ret)
1011 		return ret;
1012 
1013 	reinit_completion(&qup->xfer);
1014 	enable_irq(qup->irq);
1015 	if (!blk->is_tx_blk_mode) {
1016 		blk->tx_fifo_free = qup->out_fifo_sz;
1017 
1018 		if (is_rx)
1019 			qup_i2c_write_rx_tags_v1(qup);
1020 		else
1021 			qup_i2c_write_tx_fifo_v1(qup);
1022 	}
1023 
1024 	ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
1025 	if (ret)
1026 		goto err;
1027 
1028 	ret = qup_i2c_wait_for_complete(qup, qup->msg);
1029 	if (ret)
1030 		goto err;
1031 
1032 	ret = qup_i2c_bus_active(qup, ONE_BYTE);
1033 
1034 err:
1035 	disable_irq(qup->irq);
1036 	return ret;
1037 }
1038 
qup_i2c_write_one(struct qup_i2c_dev * qup)1039 static int qup_i2c_write_one(struct qup_i2c_dev *qup)
1040 {
1041 	struct i2c_msg *msg = qup->msg;
1042 	struct qup_i2c_block *blk = &qup->blk;
1043 
1044 	qup->pos = 0;
1045 	blk->total_tx_len = msg->len + 1;
1046 	blk->total_rx_len = 0;
1047 
1048 	return qup_i2c_conf_xfer_v1(qup, false);
1049 }
1050 
qup_i2c_read_one(struct qup_i2c_dev * qup)1051 static int qup_i2c_read_one(struct qup_i2c_dev *qup)
1052 {
1053 	struct qup_i2c_block *blk = &qup->blk;
1054 
1055 	qup->pos = 0;
1056 	blk->total_tx_len = 2;
1057 	blk->total_rx_len = qup->msg->len;
1058 
1059 	return qup_i2c_conf_xfer_v1(qup, true);
1060 }
1061 
qup_i2c_xfer(struct i2c_adapter * adap,struct i2c_msg msgs[],int num)1062 static int qup_i2c_xfer(struct i2c_adapter *adap,
1063 			struct i2c_msg msgs[],
1064 			int num)
1065 {
1066 	struct qup_i2c_dev *qup = i2c_get_adapdata(adap);
1067 	int ret, idx;
1068 
1069 	ret = pm_runtime_get_sync(qup->dev);
1070 	if (ret < 0)
1071 		goto out;
1072 
1073 	qup->bus_err = 0;
1074 	qup->qup_err = 0;
1075 
1076 	writel(1, qup->base + QUP_SW_RESET);
1077 	ret = qup_i2c_poll_state(qup, QUP_RESET_STATE);
1078 	if (ret)
1079 		goto out;
1080 
1081 	/* Configure QUP as I2C mini core */
1082 	writel(I2C_MINI_CORE | I2C_N_VAL, qup->base + QUP_CONFIG);
1083 
1084 	for (idx = 0; idx < num; idx++) {
1085 		if (qup_i2c_poll_state_i2c_master(qup)) {
1086 			ret = -EIO;
1087 			goto out;
1088 		}
1089 
1090 		if (qup_i2c_check_msg_len(&msgs[idx])) {
1091 			ret = -EINVAL;
1092 			goto out;
1093 		}
1094 
1095 		qup->msg = &msgs[idx];
1096 		if (msgs[idx].flags & I2C_M_RD)
1097 			ret = qup_i2c_read_one(qup);
1098 		else
1099 			ret = qup_i2c_write_one(qup);
1100 
1101 		if (ret)
1102 			break;
1103 
1104 		ret = qup_i2c_change_state(qup, QUP_RESET_STATE);
1105 		if (ret)
1106 			break;
1107 	}
1108 
1109 	if (ret == 0)
1110 		ret = num;
1111 out:
1112 
1113 	pm_runtime_mark_last_busy(qup->dev);
1114 	pm_runtime_put_autosuspend(qup->dev);
1115 
1116 	return ret;
1117 }
1118 
1119 /*
1120  * Configure registers related with reconfiguration during run and call it
1121  * before each i2c sub transfer.
1122  */
qup_i2c_conf_count_v2(struct qup_i2c_dev * qup)1123 static void qup_i2c_conf_count_v2(struct qup_i2c_dev *qup)
1124 {
1125 	struct qup_i2c_block *blk = &qup->blk;
1126 	u32 qup_config = I2C_MINI_CORE | I2C_N_VAL_V2;
1127 
1128 	if (blk->is_tx_blk_mode)
1129 		writel(qup->config_run | blk->total_tx_len,
1130 		       qup->base + QUP_MX_OUTPUT_CNT);
1131 	else
1132 		writel(qup->config_run | blk->total_tx_len,
1133 		       qup->base + QUP_MX_WRITE_CNT);
1134 
1135 	if (blk->total_rx_len) {
1136 		if (blk->is_rx_blk_mode)
1137 			writel(qup->config_run | blk->total_rx_len,
1138 			       qup->base + QUP_MX_INPUT_CNT);
1139 		else
1140 			writel(qup->config_run | blk->total_rx_len,
1141 			       qup->base + QUP_MX_READ_CNT);
1142 	} else {
1143 		qup_config |= QUP_NO_INPUT;
1144 	}
1145 
1146 	writel(qup_config, qup->base + QUP_CONFIG);
1147 }
1148 
1149 /*
1150  * Configure registers related with transfer mode (FIFO/Block)
1151  * before starting of i2c transfer. It will be called only once in
1152  * QUP RESET state.
1153  */
qup_i2c_conf_mode_v2(struct qup_i2c_dev * qup)1154 static void qup_i2c_conf_mode_v2(struct qup_i2c_dev *qup)
1155 {
1156 	struct qup_i2c_block *blk = &qup->blk;
1157 	u32 io_mode = QUP_REPACK_EN;
1158 
1159 	if (blk->is_tx_blk_mode) {
1160 		io_mode |= QUP_OUTPUT_BLK_MODE;
1161 		writel(0, qup->base + QUP_MX_WRITE_CNT);
1162 	} else {
1163 		writel(0, qup->base + QUP_MX_OUTPUT_CNT);
1164 	}
1165 
1166 	if (blk->is_rx_blk_mode) {
1167 		io_mode |= QUP_INPUT_BLK_MODE;
1168 		writel(0, qup->base + QUP_MX_READ_CNT);
1169 	} else {
1170 		writel(0, qup->base + QUP_MX_INPUT_CNT);
1171 	}
1172 
1173 	writel(io_mode, qup->base + QUP_IO_MODE);
1174 }
1175 
1176 /* Clear required variables before starting of any QUP v2 sub transfer. */
qup_i2c_clear_blk_v2(struct qup_i2c_block * blk)1177 static void qup_i2c_clear_blk_v2(struct qup_i2c_block *blk)
1178 {
1179 	blk->send_last_word = false;
1180 	blk->tx_tags_sent = false;
1181 	blk->tx_fifo_data = 0;
1182 	blk->tx_fifo_data_pos = 0;
1183 	blk->tx_fifo_free = 0;
1184 
1185 	blk->rx_tags_fetched = false;
1186 	blk->rx_bytes_read = false;
1187 	blk->rx_fifo_data = 0;
1188 	blk->rx_fifo_data_pos = 0;
1189 	blk->fifo_available = 0;
1190 }
1191 
1192 /* Receive data from RX FIFO for read message in QUP v2 i2c transfer. */
qup_i2c_recv_data(struct qup_i2c_dev * qup)1193 static void qup_i2c_recv_data(struct qup_i2c_dev *qup)
1194 {
1195 	struct qup_i2c_block *blk = &qup->blk;
1196 	int j;
1197 
1198 	for (j = blk->rx_fifo_data_pos;
1199 	     blk->cur_blk_len && blk->fifo_available;
1200 	     blk->cur_blk_len--, blk->fifo_available--) {
1201 		if (j == 0)
1202 			blk->rx_fifo_data = readl(qup->base + QUP_IN_FIFO_BASE);
1203 
1204 		*(blk->cur_data++) = blk->rx_fifo_data;
1205 		blk->rx_fifo_data >>= 8;
1206 
1207 		if (j == 3)
1208 			j = 0;
1209 		else
1210 			j++;
1211 	}
1212 
1213 	blk->rx_fifo_data_pos = j;
1214 }
1215 
1216 /* Receive tags for read message in QUP v2 i2c transfer. */
qup_i2c_recv_tags(struct qup_i2c_dev * qup)1217 static void qup_i2c_recv_tags(struct qup_i2c_dev *qup)
1218 {
1219 	struct qup_i2c_block *blk = &qup->blk;
1220 
1221 	blk->rx_fifo_data = readl(qup->base + QUP_IN_FIFO_BASE);
1222 	blk->rx_fifo_data >>= blk->rx_tag_len  * 8;
1223 	blk->rx_fifo_data_pos = blk->rx_tag_len;
1224 	blk->fifo_available -= blk->rx_tag_len;
1225 }
1226 
1227 /*
1228  * Read the data and tags from RX FIFO. Since in read case, the tags will be
1229  * preceded by received data bytes so
1230  * 1. Check if rx_tags_fetched is false i.e. the start of QUP block so receive
1231  *    all tag bytes and discard that.
1232  * 2. Read the data from RX FIFO. When all the data bytes have been read then
1233  *    set rx_bytes_read to true.
1234  */
qup_i2c_read_rx_fifo_v2(struct qup_i2c_dev * qup)1235 static void qup_i2c_read_rx_fifo_v2(struct qup_i2c_dev *qup)
1236 {
1237 	struct qup_i2c_block *blk = &qup->blk;
1238 
1239 	if (!blk->rx_tags_fetched) {
1240 		qup_i2c_recv_tags(qup);
1241 		blk->rx_tags_fetched = true;
1242 	}
1243 
1244 	qup_i2c_recv_data(qup);
1245 	if (!blk->cur_blk_len)
1246 		blk->rx_bytes_read = true;
1247 }
1248 
1249 /*
1250  * Write bytes in TX FIFO for write message in QUP v2 i2c transfer. QUP TX FIFO
1251  * write works on word basis (4 bytes). Append new data byte write for TX FIFO
1252  * in tx_fifo_data and write to TX FIFO when all the 4 bytes are present.
1253  */
1254 static void
qup_i2c_write_blk_data(struct qup_i2c_dev * qup,u8 ** data,unsigned int * len)1255 qup_i2c_write_blk_data(struct qup_i2c_dev *qup, u8 **data, unsigned int *len)
1256 {
1257 	struct qup_i2c_block *blk = &qup->blk;
1258 	unsigned int j;
1259 
1260 	for (j = blk->tx_fifo_data_pos; *len && blk->tx_fifo_free;
1261 	     (*len)--, blk->tx_fifo_free--) {
1262 		blk->tx_fifo_data |= *(*data)++ << (j * 8);
1263 		if (j == 3) {
1264 			writel(blk->tx_fifo_data,
1265 			       qup->base + QUP_OUT_FIFO_BASE);
1266 			blk->tx_fifo_data = 0x0;
1267 			j = 0;
1268 		} else {
1269 			j++;
1270 		}
1271 	}
1272 
1273 	blk->tx_fifo_data_pos = j;
1274 }
1275 
1276 /* Transfer tags for read message in QUP v2 i2c transfer. */
qup_i2c_write_rx_tags_v2(struct qup_i2c_dev * qup)1277 static void qup_i2c_write_rx_tags_v2(struct qup_i2c_dev *qup)
1278 {
1279 	struct qup_i2c_block *blk = &qup->blk;
1280 
1281 	qup_i2c_write_blk_data(qup, &blk->cur_tx_tags, &blk->tx_tag_len);
1282 	if (blk->tx_fifo_data_pos)
1283 		writel(blk->tx_fifo_data, qup->base + QUP_OUT_FIFO_BASE);
1284 }
1285 
1286 /*
1287  * Write the data and tags in TX FIFO. Since in write case, both tags and data
1288  * need to be written and QUP write tags can have maximum 256 data length, so
1289  *
1290  * 1. Check if tx_tags_sent is false i.e. the start of QUP block so write the
1291  *    tags to TX FIFO and set tx_tags_sent to true.
1292  * 2. Check if send_last_word is true. It will be set when last few data bytes
1293  *    (less than 4 bytes) are remaining to be written in FIFO because of no FIFO
1294  *    space. All this data bytes are available in tx_fifo_data so write this
1295  *    in FIFO.
1296  * 3. Write the data to TX FIFO and check for cur_blk_len. If it is non zero
1297  *    then more data is pending otherwise following 3 cases can be possible
1298  *    a. if tx_fifo_data_pos is zero i.e. all the data bytes in this block
1299  *       have been written in TX FIFO so nothing else is required.
1300  *    b. tx_fifo_free is non zero i.e tx FIFO is free so copy the remaining data
1301  *       from tx_fifo_data to tx FIFO. Since, qup_i2c_write_blk_data do write
1302  *	 in 4 bytes and FIFO space is in multiple of 4 bytes so tx_fifo_free
1303  *       will be always greater than or equal to 4 bytes.
1304  *    c. tx_fifo_free is zero. In this case, last few bytes (less than 4
1305  *       bytes) are copied to tx_fifo_data but couldn't be sent because of
1306  *       FIFO full so make send_last_word true.
1307  */
qup_i2c_write_tx_fifo_v2(struct qup_i2c_dev * qup)1308 static void qup_i2c_write_tx_fifo_v2(struct qup_i2c_dev *qup)
1309 {
1310 	struct qup_i2c_block *blk = &qup->blk;
1311 
1312 	if (!blk->tx_tags_sent) {
1313 		qup_i2c_write_blk_data(qup, &blk->cur_tx_tags,
1314 				       &blk->tx_tag_len);
1315 		blk->tx_tags_sent = true;
1316 	}
1317 
1318 	if (blk->send_last_word)
1319 		goto send_last_word;
1320 
1321 	qup_i2c_write_blk_data(qup, &blk->cur_data, &blk->cur_blk_len);
1322 	if (!blk->cur_blk_len) {
1323 		if (!blk->tx_fifo_data_pos)
1324 			return;
1325 
1326 		if (blk->tx_fifo_free)
1327 			goto send_last_word;
1328 
1329 		blk->send_last_word = true;
1330 	}
1331 
1332 	return;
1333 
1334 send_last_word:
1335 	writel(blk->tx_fifo_data, qup->base + QUP_OUT_FIFO_BASE);
1336 }
1337 
1338 /*
1339  * Main transfer function which read or write i2c data.
1340  * The QUP v2 supports reconfiguration during run in which multiple i2c sub
1341  * transfers can be scheduled.
1342  */
1343 static int
qup_i2c_conf_xfer_v2(struct qup_i2c_dev * qup,bool is_rx,bool is_first,bool change_pause_state)1344 qup_i2c_conf_xfer_v2(struct qup_i2c_dev *qup, bool is_rx, bool is_first,
1345 		     bool change_pause_state)
1346 {
1347 	struct qup_i2c_block *blk = &qup->blk;
1348 	struct i2c_msg *msg = qup->msg;
1349 	int ret;
1350 
1351 	/*
1352 	 * Check if its SMBus Block read for which the top level read will be
1353 	 * done into 2 QUP reads. One with message length 1 while other one is
1354 	 * with actual length.
1355 	 */
1356 	if (qup_i2c_check_msg_len(msg)) {
1357 		if (qup->is_smbus_read) {
1358 			/*
1359 			 * If the message length is already read in
1360 			 * the first byte of the buffer, account for
1361 			 * that by setting the offset
1362 			 */
1363 			blk->cur_data += 1;
1364 			is_first = false;
1365 		} else {
1366 			change_pause_state = false;
1367 		}
1368 	}
1369 
1370 	qup->config_run = is_first ? 0 : QUP_I2C_MX_CONFIG_DURING_RUN;
1371 
1372 	qup_i2c_clear_blk_v2(blk);
1373 	qup_i2c_conf_count_v2(qup);
1374 
1375 	/* If it is first sub transfer, then configure i2c bus clocks */
1376 	if (is_first) {
1377 		ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
1378 		if (ret)
1379 			return ret;
1380 
1381 		writel(qup->clk_ctl, qup->base + QUP_I2C_CLK_CTL);
1382 
1383 		ret = qup_i2c_change_state(qup, QUP_PAUSE_STATE);
1384 		if (ret)
1385 			return ret;
1386 	}
1387 
1388 	reinit_completion(&qup->xfer);
1389 	enable_irq(qup->irq);
1390 	/*
1391 	 * In FIFO mode, tx FIFO can be written directly while in block mode the
1392 	 * it will be written after getting OUT_BLOCK_WRITE_REQ interrupt
1393 	 */
1394 	if (!blk->is_tx_blk_mode) {
1395 		blk->tx_fifo_free = qup->out_fifo_sz;
1396 
1397 		if (is_rx)
1398 			qup_i2c_write_rx_tags_v2(qup);
1399 		else
1400 			qup_i2c_write_tx_fifo_v2(qup);
1401 	}
1402 
1403 	ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
1404 	if (ret)
1405 		goto err;
1406 
1407 	ret = qup_i2c_wait_for_complete(qup, msg);
1408 	if (ret)
1409 		goto err;
1410 
1411 	/* Move to pause state for all the transfers, except last one */
1412 	if (change_pause_state) {
1413 		ret = qup_i2c_change_state(qup, QUP_PAUSE_STATE);
1414 		if (ret)
1415 			goto err;
1416 	}
1417 
1418 err:
1419 	disable_irq(qup->irq);
1420 	return ret;
1421 }
1422 
1423 /*
1424  * Transfer one read/write message in i2c transfer. It splits the message into
1425  * multiple of blk_xfer_limit data length blocks and schedule each
1426  * QUP block individually.
1427  */
qup_i2c_xfer_v2_msg(struct qup_i2c_dev * qup,int msg_id,bool is_rx)1428 static int qup_i2c_xfer_v2_msg(struct qup_i2c_dev *qup, int msg_id, bool is_rx)
1429 {
1430 	int ret = 0;
1431 	unsigned int data_len, i;
1432 	struct i2c_msg *msg = qup->msg;
1433 	struct qup_i2c_block *blk = &qup->blk;
1434 	u8 *msg_buf = msg->buf;
1435 
1436 	qup->blk_xfer_limit = is_rx ? RECV_MAX_DATA_LEN : QUP_READ_LIMIT;
1437 	qup_i2c_set_blk_data(qup, msg);
1438 
1439 	for (i = 0; i < blk->count; i++) {
1440 		data_len =  qup_i2c_get_data_len(qup);
1441 		blk->pos = i;
1442 		blk->cur_tx_tags = blk->tags;
1443 		blk->cur_blk_len = data_len;
1444 		blk->tx_tag_len =
1445 			qup_i2c_set_tags(blk->cur_tx_tags, qup, qup->msg);
1446 
1447 		blk->cur_data = msg_buf;
1448 
1449 		if (is_rx) {
1450 			blk->total_tx_len = blk->tx_tag_len;
1451 			blk->rx_tag_len = 2;
1452 			blk->total_rx_len = blk->rx_tag_len + data_len;
1453 		} else {
1454 			blk->total_tx_len = blk->tx_tag_len + data_len;
1455 			blk->total_rx_len = 0;
1456 		}
1457 
1458 		ret = qup_i2c_conf_xfer_v2(qup, is_rx, !msg_id && !i,
1459 					   !qup->is_last || i < blk->count - 1);
1460 		if (ret)
1461 			return ret;
1462 
1463 		/* Handle SMBus block read length */
1464 		if (qup_i2c_check_msg_len(msg) && msg->len == 1 &&
1465 		    !qup->is_smbus_read) {
1466 			if (msg->buf[0] > I2C_SMBUS_BLOCK_MAX)
1467 				return -EPROTO;
1468 
1469 			msg->len = msg->buf[0];
1470 			qup->is_smbus_read = true;
1471 			ret = qup_i2c_xfer_v2_msg(qup, msg_id, true);
1472 			qup->is_smbus_read = false;
1473 			if (ret)
1474 				return ret;
1475 
1476 			msg->len += 1;
1477 		}
1478 
1479 		msg_buf += data_len;
1480 		blk->data_len -= qup->blk_xfer_limit;
1481 	}
1482 
1483 	return ret;
1484 }
1485 
1486 /*
1487  * QUP v2 supports 3 modes
1488  * Programmed IO using FIFO mode : Less than FIFO size
1489  * Programmed IO using Block mode : Greater than FIFO size
1490  * DMA using BAM : Appropriate for any transaction size but the address should
1491  *		   be DMA applicable
1492  *
1493  * This function determines the mode which will be used for this transfer. An
1494  * i2c transfer contains multiple message. Following are the rules to determine
1495  * the mode used.
1496  * 1. Determine complete length, maximum tx and rx length for complete transfer.
1497  * 2. If complete transfer length is greater than fifo size then use the DMA
1498  *    mode.
1499  * 3. In FIFO or block mode, tx and rx can operate in different mode so check
1500  *    for maximum tx and rx length to determine mode.
1501  */
1502 static int
qup_i2c_determine_mode_v2(struct qup_i2c_dev * qup,struct i2c_msg msgs[],int num)1503 qup_i2c_determine_mode_v2(struct qup_i2c_dev *qup,
1504 			  struct i2c_msg msgs[], int num)
1505 {
1506 	int idx;
1507 	bool no_dma = false;
1508 	unsigned int max_tx_len = 0, max_rx_len = 0, total_len = 0;
1509 
1510 	/* All i2c_msgs should be transferred using either dma or cpu */
1511 	for (idx = 0; idx < num; idx++) {
1512 		if (msgs[idx].flags & I2C_M_RD)
1513 			max_rx_len = max_t(unsigned int, max_rx_len,
1514 					   msgs[idx].len);
1515 		else
1516 			max_tx_len = max_t(unsigned int, max_tx_len,
1517 					   msgs[idx].len);
1518 
1519 		if (is_vmalloc_addr(msgs[idx].buf))
1520 			no_dma = true;
1521 
1522 		total_len += msgs[idx].len;
1523 	}
1524 
1525 	if (!no_dma && qup->is_dma &&
1526 	    (total_len > qup->out_fifo_sz || total_len > qup->in_fifo_sz)) {
1527 		qup->use_dma = true;
1528 	} else {
1529 		qup->blk.is_tx_blk_mode = max_tx_len > qup->out_fifo_sz -
1530 			QUP_MAX_TAGS_LEN;
1531 		qup->blk.is_rx_blk_mode = max_rx_len > qup->in_fifo_sz -
1532 			READ_RX_TAGS_LEN;
1533 	}
1534 
1535 	return 0;
1536 }
1537 
qup_i2c_xfer_v2(struct i2c_adapter * adap,struct i2c_msg msgs[],int num)1538 static int qup_i2c_xfer_v2(struct i2c_adapter *adap,
1539 			   struct i2c_msg msgs[],
1540 			   int num)
1541 {
1542 	struct qup_i2c_dev *qup = i2c_get_adapdata(adap);
1543 	int ret, idx = 0;
1544 
1545 	qup->bus_err = 0;
1546 	qup->qup_err = 0;
1547 
1548 	ret = pm_runtime_get_sync(qup->dev);
1549 	if (ret < 0)
1550 		goto out;
1551 
1552 	ret = qup_i2c_determine_mode_v2(qup, msgs, num);
1553 	if (ret)
1554 		goto out;
1555 
1556 	writel(1, qup->base + QUP_SW_RESET);
1557 	ret = qup_i2c_poll_state(qup, QUP_RESET_STATE);
1558 	if (ret)
1559 		goto out;
1560 
1561 	/* Configure QUP as I2C mini core */
1562 	writel(I2C_MINI_CORE | I2C_N_VAL_V2, qup->base + QUP_CONFIG);
1563 	writel(QUP_V2_TAGS_EN, qup->base + QUP_I2C_MASTER_GEN);
1564 
1565 	if (qup_i2c_poll_state_i2c_master(qup)) {
1566 		ret = -EIO;
1567 		goto out;
1568 	}
1569 
1570 	if (qup->use_dma) {
1571 		reinit_completion(&qup->xfer);
1572 		ret = qup_i2c_bam_xfer(adap, &msgs[0], num);
1573 		qup->use_dma = false;
1574 	} else {
1575 		qup_i2c_conf_mode_v2(qup);
1576 
1577 		for (idx = 0; idx < num; idx++) {
1578 			qup->msg = &msgs[idx];
1579 			qup->is_last = idx == (num - 1);
1580 
1581 			ret = qup_i2c_xfer_v2_msg(qup, idx,
1582 					!!(msgs[idx].flags & I2C_M_RD));
1583 			if (ret)
1584 				break;
1585 		}
1586 		qup->msg = NULL;
1587 	}
1588 
1589 	if (!ret)
1590 		ret = qup_i2c_bus_active(qup, ONE_BYTE);
1591 
1592 	if (!ret)
1593 		qup_i2c_change_state(qup, QUP_RESET_STATE);
1594 
1595 	if (ret == 0)
1596 		ret = num;
1597 out:
1598 	pm_runtime_mark_last_busy(qup->dev);
1599 	pm_runtime_put_autosuspend(qup->dev);
1600 
1601 	return ret;
1602 }
1603 
qup_i2c_func(struct i2c_adapter * adap)1604 static u32 qup_i2c_func(struct i2c_adapter *adap)
1605 {
1606 	return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL_ALL & ~I2C_FUNC_SMBUS_QUICK);
1607 }
1608 
1609 static const struct i2c_algorithm qup_i2c_algo = {
1610 	.master_xfer	= qup_i2c_xfer,
1611 	.functionality	= qup_i2c_func,
1612 };
1613 
1614 static const struct i2c_algorithm qup_i2c_algo_v2 = {
1615 	.master_xfer	= qup_i2c_xfer_v2,
1616 	.functionality	= qup_i2c_func,
1617 };
1618 
1619 /*
1620  * The QUP block will issue a NACK and STOP on the bus when reaching
1621  * the end of the read, the length of the read is specified as one byte
1622  * which limits the possible read to 256 (QUP_READ_LIMIT) bytes.
1623  */
1624 static const struct i2c_adapter_quirks qup_i2c_quirks = {
1625 	.flags = I2C_AQ_NO_ZERO_LEN,
1626 	.max_read_len = QUP_READ_LIMIT,
1627 };
1628 
1629 static const struct i2c_adapter_quirks qup_i2c_quirks_v2 = {
1630 	.flags = I2C_AQ_NO_ZERO_LEN,
1631 };
1632 
qup_i2c_enable_clocks(struct qup_i2c_dev * qup)1633 static void qup_i2c_enable_clocks(struct qup_i2c_dev *qup)
1634 {
1635 	clk_prepare_enable(qup->clk);
1636 	clk_prepare_enable(qup->pclk);
1637 }
1638 
qup_i2c_disable_clocks(struct qup_i2c_dev * qup)1639 static void qup_i2c_disable_clocks(struct qup_i2c_dev *qup)
1640 {
1641 	u32 config;
1642 
1643 	qup_i2c_change_state(qup, QUP_RESET_STATE);
1644 	clk_disable_unprepare(qup->clk);
1645 	config = readl(qup->base + QUP_CONFIG);
1646 	config |= QUP_CLOCK_AUTO_GATE;
1647 	writel(config, qup->base + QUP_CONFIG);
1648 	clk_disable_unprepare(qup->pclk);
1649 }
1650 
1651 static const struct acpi_device_id qup_i2c_acpi_match[] = {
1652 	{ "QCOM8010"},
1653 	{ },
1654 };
1655 MODULE_DEVICE_TABLE(acpi, qup_i2c_acpi_match);
1656 
qup_i2c_probe(struct platform_device * pdev)1657 static int qup_i2c_probe(struct platform_device *pdev)
1658 {
1659 	static const int blk_sizes[] = {4, 16, 32};
1660 	struct qup_i2c_dev *qup;
1661 	unsigned long one_bit_t;
1662 	u32 io_mode, hw_ver, size;
1663 	int ret, fs_div, hs_div;
1664 	u32 src_clk_freq = DEFAULT_SRC_CLK;
1665 	u32 clk_freq = DEFAULT_CLK_FREQ;
1666 	int blocks;
1667 	bool is_qup_v1;
1668 
1669 	qup = devm_kzalloc(&pdev->dev, sizeof(*qup), GFP_KERNEL);
1670 	if (!qup)
1671 		return -ENOMEM;
1672 
1673 	qup->dev = &pdev->dev;
1674 	init_completion(&qup->xfer);
1675 	platform_set_drvdata(pdev, qup);
1676 
1677 	if (scl_freq) {
1678 		dev_notice(qup->dev, "Using override frequency of %u\n", scl_freq);
1679 		clk_freq = scl_freq;
1680 	} else {
1681 		ret = device_property_read_u32(qup->dev, "clock-frequency", &clk_freq);
1682 		if (ret) {
1683 			dev_notice(qup->dev, "using default clock-frequency %d",
1684 				DEFAULT_CLK_FREQ);
1685 		}
1686 	}
1687 
1688 	if (of_device_is_compatible(pdev->dev.of_node, "qcom,i2c-qup-v1.1.1")) {
1689 		qup->adap.algo = &qup_i2c_algo;
1690 		qup->adap.quirks = &qup_i2c_quirks;
1691 		is_qup_v1 = true;
1692 	} else {
1693 		qup->adap.algo = &qup_i2c_algo_v2;
1694 		qup->adap.quirks = &qup_i2c_quirks_v2;
1695 		is_qup_v1 = false;
1696 		if (acpi_match_device(qup_i2c_acpi_match, qup->dev))
1697 			goto nodma;
1698 		else
1699 			ret = qup_i2c_req_dma(qup);
1700 
1701 		if (ret == -EPROBE_DEFER)
1702 			goto fail_dma;
1703 		else if (ret != 0)
1704 			goto nodma;
1705 
1706 		qup->max_xfer_sg_len = (MX_BLOCKS << 1);
1707 		blocks = (MX_DMA_BLOCKS << 1) + 1;
1708 		qup->btx.sg = devm_kcalloc(&pdev->dev,
1709 					   blocks, sizeof(*qup->btx.sg),
1710 					   GFP_KERNEL);
1711 		if (!qup->btx.sg) {
1712 			ret = -ENOMEM;
1713 			goto fail_dma;
1714 		}
1715 		sg_init_table(qup->btx.sg, blocks);
1716 
1717 		qup->brx.sg = devm_kcalloc(&pdev->dev,
1718 					   blocks, sizeof(*qup->brx.sg),
1719 					   GFP_KERNEL);
1720 		if (!qup->brx.sg) {
1721 			ret = -ENOMEM;
1722 			goto fail_dma;
1723 		}
1724 		sg_init_table(qup->brx.sg, blocks);
1725 
1726 		/* 2 tag bytes for each block + 5 for start, stop tags */
1727 		size = blocks * 2 + 5;
1728 
1729 		qup->start_tag.start = devm_kzalloc(&pdev->dev,
1730 						    size, GFP_KERNEL);
1731 		if (!qup->start_tag.start) {
1732 			ret = -ENOMEM;
1733 			goto fail_dma;
1734 		}
1735 
1736 		qup->brx.tag.start = devm_kzalloc(&pdev->dev, 2, GFP_KERNEL);
1737 		if (!qup->brx.tag.start) {
1738 			ret = -ENOMEM;
1739 			goto fail_dma;
1740 		}
1741 
1742 		qup->btx.tag.start = devm_kzalloc(&pdev->dev, 2, GFP_KERNEL);
1743 		if (!qup->btx.tag.start) {
1744 			ret = -ENOMEM;
1745 			goto fail_dma;
1746 		}
1747 		qup->is_dma = true;
1748 	}
1749 
1750 nodma:
1751 	/* We support frequencies up to FAST Mode Plus (1MHz) */
1752 	if (!clk_freq || clk_freq > I2C_MAX_FAST_MODE_PLUS_FREQ) {
1753 		dev_err(qup->dev, "clock frequency not supported %d\n",
1754 			clk_freq);
1755 		ret = -EINVAL;
1756 		goto fail_dma;
1757 	}
1758 
1759 	qup->base = devm_platform_ioremap_resource(pdev, 0);
1760 	if (IS_ERR(qup->base)) {
1761 		ret = PTR_ERR(qup->base);
1762 		goto fail_dma;
1763 	}
1764 
1765 	qup->irq = platform_get_irq(pdev, 0);
1766 	if (qup->irq < 0) {
1767 		ret = qup->irq;
1768 		goto fail_dma;
1769 	}
1770 
1771 	if (has_acpi_companion(qup->dev)) {
1772 		ret = device_property_read_u32(qup->dev,
1773 				"src-clock-hz", &src_clk_freq);
1774 		if (ret) {
1775 			dev_notice(qup->dev, "using default src-clock-hz %d",
1776 				DEFAULT_SRC_CLK);
1777 		}
1778 		ACPI_COMPANION_SET(&qup->adap.dev, ACPI_COMPANION(qup->dev));
1779 	} else {
1780 		qup->clk = devm_clk_get(qup->dev, "core");
1781 		if (IS_ERR(qup->clk)) {
1782 			dev_err(qup->dev, "Could not get core clock\n");
1783 			ret = PTR_ERR(qup->clk);
1784 			goto fail_dma;
1785 		}
1786 
1787 		qup->pclk = devm_clk_get(qup->dev, "iface");
1788 		if (IS_ERR(qup->pclk)) {
1789 			dev_err(qup->dev, "Could not get iface clock\n");
1790 			ret = PTR_ERR(qup->pclk);
1791 			goto fail_dma;
1792 		}
1793 		qup_i2c_enable_clocks(qup);
1794 		src_clk_freq = clk_get_rate(qup->clk);
1795 	}
1796 
1797 	/*
1798 	 * Bootloaders might leave a pending interrupt on certain QUP's,
1799 	 * so we reset the core before registering for interrupts.
1800 	 */
1801 	writel(1, qup->base + QUP_SW_RESET);
1802 	ret = qup_i2c_poll_state_valid(qup);
1803 	if (ret)
1804 		goto fail;
1805 
1806 	ret = devm_request_irq(qup->dev, qup->irq, qup_i2c_interrupt,
1807 			       IRQF_TRIGGER_HIGH | IRQF_NO_AUTOEN,
1808 			       "i2c_qup", qup);
1809 	if (ret) {
1810 		dev_err(qup->dev, "Request %d IRQ failed\n", qup->irq);
1811 		goto fail;
1812 	}
1813 
1814 	hw_ver = readl(qup->base + QUP_HW_VERSION);
1815 	dev_dbg(qup->dev, "Revision %x\n", hw_ver);
1816 
1817 	io_mode = readl(qup->base + QUP_IO_MODE);
1818 
1819 	/*
1820 	 * The block/fifo size w.r.t. 'actual data' is 1/2 due to 'tag'
1821 	 * associated with each byte written/received
1822 	 */
1823 	size = QUP_OUTPUT_BLOCK_SIZE(io_mode);
1824 	if (size >= ARRAY_SIZE(blk_sizes)) {
1825 		ret = -EIO;
1826 		goto fail;
1827 	}
1828 	qup->out_blk_sz = blk_sizes[size];
1829 
1830 	size = QUP_INPUT_BLOCK_SIZE(io_mode);
1831 	if (size >= ARRAY_SIZE(blk_sizes)) {
1832 		ret = -EIO;
1833 		goto fail;
1834 	}
1835 	qup->in_blk_sz = blk_sizes[size];
1836 
1837 	if (is_qup_v1) {
1838 		/*
1839 		 * in QUP v1, QUP_CONFIG uses N as 15 i.e 16 bits constitutes a
1840 		 * single transfer but the block size is in bytes so divide the
1841 		 * in_blk_sz and out_blk_sz by 2
1842 		 */
1843 		qup->in_blk_sz /= 2;
1844 		qup->out_blk_sz /= 2;
1845 		qup->write_tx_fifo = qup_i2c_write_tx_fifo_v1;
1846 		qup->read_rx_fifo = qup_i2c_read_rx_fifo_v1;
1847 		qup->write_rx_tags = qup_i2c_write_rx_tags_v1;
1848 	} else {
1849 		qup->write_tx_fifo = qup_i2c_write_tx_fifo_v2;
1850 		qup->read_rx_fifo = qup_i2c_read_rx_fifo_v2;
1851 		qup->write_rx_tags = qup_i2c_write_rx_tags_v2;
1852 	}
1853 
1854 	size = QUP_OUTPUT_FIFO_SIZE(io_mode);
1855 	qup->out_fifo_sz = qup->out_blk_sz * (2 << size);
1856 
1857 	size = QUP_INPUT_FIFO_SIZE(io_mode);
1858 	qup->in_fifo_sz = qup->in_blk_sz * (2 << size);
1859 
1860 	hs_div = 3;
1861 	if (clk_freq <= I2C_MAX_STANDARD_MODE_FREQ) {
1862 		fs_div = ((src_clk_freq / clk_freq) / 2) - 3;
1863 		qup->clk_ctl = (hs_div << 8) | (fs_div & 0xff);
1864 	} else {
1865 		/* 33%/66% duty cycle */
1866 		fs_div = ((src_clk_freq / clk_freq) - 6) * 2 / 3;
1867 		qup->clk_ctl = ((fs_div / 2) << 16) | (hs_div << 8) | (fs_div & 0xff);
1868 	}
1869 
1870 	/*
1871 	 * Time it takes for a byte to be clocked out on the bus.
1872 	 * Each byte takes 9 clock cycles (8 bits + 1 ack).
1873 	 */
1874 	one_bit_t = (USEC_PER_SEC / clk_freq) + 1;
1875 	qup->one_byte_t = one_bit_t * 9;
1876 	qup->xfer_timeout = TOUT_MIN * HZ +
1877 		usecs_to_jiffies(MX_DMA_TX_RX_LEN * qup->one_byte_t);
1878 
1879 	dev_dbg(qup->dev, "IN:block:%d, fifo:%d, OUT:block:%d, fifo:%d\n",
1880 		qup->in_blk_sz, qup->in_fifo_sz,
1881 		qup->out_blk_sz, qup->out_fifo_sz);
1882 
1883 	i2c_set_adapdata(&qup->adap, qup);
1884 	qup->adap.dev.parent = qup->dev;
1885 	qup->adap.dev.of_node = pdev->dev.of_node;
1886 	qup->is_last = true;
1887 
1888 	strscpy(qup->adap.name, "QUP I2C adapter", sizeof(qup->adap.name));
1889 
1890 	pm_runtime_set_autosuspend_delay(qup->dev, MSEC_PER_SEC);
1891 	pm_runtime_use_autosuspend(qup->dev);
1892 	pm_runtime_set_active(qup->dev);
1893 	pm_runtime_enable(qup->dev);
1894 
1895 	ret = i2c_add_adapter(&qup->adap);
1896 	if (ret)
1897 		goto fail_runtime;
1898 
1899 	return 0;
1900 
1901 fail_runtime:
1902 	pm_runtime_disable(qup->dev);
1903 	pm_runtime_set_suspended(qup->dev);
1904 fail:
1905 	qup_i2c_disable_clocks(qup);
1906 fail_dma:
1907 	if (qup->btx.dma)
1908 		dma_release_channel(qup->btx.dma);
1909 	if (qup->brx.dma)
1910 		dma_release_channel(qup->brx.dma);
1911 	return ret;
1912 }
1913 
qup_i2c_remove(struct platform_device * pdev)1914 static void qup_i2c_remove(struct platform_device *pdev)
1915 {
1916 	struct qup_i2c_dev *qup = platform_get_drvdata(pdev);
1917 
1918 	if (qup->is_dma) {
1919 		dma_release_channel(qup->btx.dma);
1920 		dma_release_channel(qup->brx.dma);
1921 	}
1922 
1923 	disable_irq(qup->irq);
1924 	qup_i2c_disable_clocks(qup);
1925 	i2c_del_adapter(&qup->adap);
1926 	pm_runtime_disable(qup->dev);
1927 	pm_runtime_set_suspended(qup->dev);
1928 }
1929 
qup_i2c_pm_suspend_runtime(struct device * device)1930 static int qup_i2c_pm_suspend_runtime(struct device *device)
1931 {
1932 	struct qup_i2c_dev *qup = dev_get_drvdata(device);
1933 
1934 	dev_dbg(device, "pm_runtime: suspending...\n");
1935 	qup_i2c_disable_clocks(qup);
1936 	return 0;
1937 }
1938 
qup_i2c_pm_resume_runtime(struct device * device)1939 static int qup_i2c_pm_resume_runtime(struct device *device)
1940 {
1941 	struct qup_i2c_dev *qup = dev_get_drvdata(device);
1942 
1943 	dev_dbg(device, "pm_runtime: resuming...\n");
1944 	qup_i2c_enable_clocks(qup);
1945 	return 0;
1946 }
1947 
qup_i2c_suspend(struct device * device)1948 static int qup_i2c_suspend(struct device *device)
1949 {
1950 	if (!pm_runtime_suspended(device))
1951 		return qup_i2c_pm_suspend_runtime(device);
1952 	return 0;
1953 }
1954 
qup_i2c_resume(struct device * device)1955 static int qup_i2c_resume(struct device *device)
1956 {
1957 	qup_i2c_pm_resume_runtime(device);
1958 	pm_runtime_mark_last_busy(device);
1959 	pm_request_autosuspend(device);
1960 	return 0;
1961 }
1962 
1963 static const struct dev_pm_ops qup_i2c_qup_pm_ops = {
1964 	SYSTEM_SLEEP_PM_OPS(qup_i2c_suspend, qup_i2c_resume)
1965 	RUNTIME_PM_OPS(qup_i2c_pm_suspend_runtime,
1966 		       qup_i2c_pm_resume_runtime, NULL)
1967 };
1968 
1969 static const struct of_device_id qup_i2c_dt_match[] = {
1970 	{ .compatible = "qcom,i2c-qup-v1.1.1" },
1971 	{ .compatible = "qcom,i2c-qup-v2.1.1" },
1972 	{ .compatible = "qcom,i2c-qup-v2.2.1" },
1973 	{}
1974 };
1975 MODULE_DEVICE_TABLE(of, qup_i2c_dt_match);
1976 
1977 static struct platform_driver qup_i2c_driver = {
1978 	.probe  = qup_i2c_probe,
1979 	.remove_new = qup_i2c_remove,
1980 	.driver = {
1981 		.name = "i2c_qup",
1982 		.pm = pm_ptr(&qup_i2c_qup_pm_ops),
1983 		.of_match_table = qup_i2c_dt_match,
1984 		.acpi_match_table = ACPI_PTR(qup_i2c_acpi_match),
1985 	},
1986 };
1987 
1988 module_platform_driver(qup_i2c_driver);
1989 
1990 MODULE_LICENSE("GPL v2");
1991 MODULE_ALIAS("platform:i2c_qup");
1992