xref: /openbmc/linux/drivers/i2c/busses/i2c-qup.c (revision 45ad842eafe484cc32e533823bc71878d1ac4a90)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2009-2013, 2016-2018, The Linux Foundation. All rights reserved.
4  * Copyright (c) 2014, Sony Mobile Communications AB.
5  *
6  */
7 
8 #include <linux/acpi.h>
9 #include <linux/atomic.h>
10 #include <linux/clk.h>
11 #include <linux/delay.h>
12 #include <linux/dmaengine.h>
13 #include <linux/dmapool.h>
14 #include <linux/dma-mapping.h>
15 #include <linux/err.h>
16 #include <linux/i2c.h>
17 #include <linux/interconnect.h>
18 #include <linux/interrupt.h>
19 #include <linux/io.h>
20 #include <linux/module.h>
21 #include <linux/of.h>
22 #include <linux/platform_device.h>
23 #include <linux/pm_runtime.h>
24 #include <linux/scatterlist.h>
25 
26 /* QUP Registers */
27 #define QUP_CONFIG		0x000
28 #define QUP_STATE		0x004
29 #define QUP_IO_MODE		0x008
30 #define QUP_SW_RESET		0x00c
31 #define QUP_OPERATIONAL		0x018
32 #define QUP_ERROR_FLAGS		0x01c
33 #define QUP_ERROR_FLAGS_EN	0x020
34 #define QUP_OPERATIONAL_MASK	0x028
35 #define QUP_HW_VERSION		0x030
36 #define QUP_MX_OUTPUT_CNT	0x100
37 #define QUP_OUT_FIFO_BASE	0x110
38 #define QUP_MX_WRITE_CNT	0x150
39 #define QUP_MX_INPUT_CNT	0x200
40 #define QUP_MX_READ_CNT		0x208
41 #define QUP_IN_FIFO_BASE	0x218
42 #define QUP_I2C_CLK_CTL		0x400
43 #define QUP_I2C_STATUS		0x404
44 #define QUP_I2C_MASTER_GEN	0x408
45 
46 /* QUP States and reset values */
47 #define QUP_RESET_STATE		0
48 #define QUP_RUN_STATE		1
49 #define QUP_PAUSE_STATE		3
50 #define QUP_STATE_MASK		3
51 
52 #define QUP_STATE_VALID		BIT(2)
53 #define QUP_I2C_MAST_GEN	BIT(4)
54 #define QUP_I2C_FLUSH		BIT(6)
55 
56 #define QUP_OPERATIONAL_RESET	0x000ff0
57 #define QUP_I2C_STATUS_RESET	0xfffffc
58 
59 /* QUP OPERATIONAL FLAGS */
60 #define QUP_I2C_NACK_FLAG	BIT(3)
61 #define QUP_OUT_NOT_EMPTY	BIT(4)
62 #define QUP_IN_NOT_EMPTY	BIT(5)
63 #define QUP_OUT_FULL		BIT(6)
64 #define QUP_OUT_SVC_FLAG	BIT(8)
65 #define QUP_IN_SVC_FLAG		BIT(9)
66 #define QUP_MX_OUTPUT_DONE	BIT(10)
67 #define QUP_MX_INPUT_DONE	BIT(11)
68 #define OUT_BLOCK_WRITE_REQ	BIT(12)
69 #define IN_BLOCK_READ_REQ	BIT(13)
70 
71 /* I2C mini core related values */
72 #define QUP_NO_INPUT		BIT(7)
73 #define QUP_CLOCK_AUTO_GATE	BIT(13)
74 #define I2C_MINI_CORE		(2 << 8)
75 #define I2C_N_VAL		15
76 #define I2C_N_VAL_V2		7
77 
78 /* Most significant word offset in FIFO port */
79 #define QUP_MSW_SHIFT		(I2C_N_VAL + 1)
80 
81 /* Packing/Unpacking words in FIFOs, and IO modes */
82 #define QUP_OUTPUT_BLK_MODE	(1 << 10)
83 #define QUP_OUTPUT_BAM_MODE	(3 << 10)
84 #define QUP_INPUT_BLK_MODE	(1 << 12)
85 #define QUP_INPUT_BAM_MODE	(3 << 12)
86 #define QUP_BAM_MODE		(QUP_OUTPUT_BAM_MODE | QUP_INPUT_BAM_MODE)
87 #define QUP_UNPACK_EN		BIT(14)
88 #define QUP_PACK_EN		BIT(15)
89 
90 #define QUP_REPACK_EN		(QUP_UNPACK_EN | QUP_PACK_EN)
91 #define QUP_V2_TAGS_EN		1
92 
93 #define QUP_OUTPUT_BLOCK_SIZE(x)(((x) >> 0) & 0x03)
94 #define QUP_OUTPUT_FIFO_SIZE(x)	(((x) >> 2) & 0x07)
95 #define QUP_INPUT_BLOCK_SIZE(x)	(((x) >> 5) & 0x03)
96 #define QUP_INPUT_FIFO_SIZE(x)	(((x) >> 7) & 0x07)
97 
98 /* QUP tags */
99 #define QUP_TAG_START		(1 << 8)
100 #define QUP_TAG_DATA		(2 << 8)
101 #define QUP_TAG_STOP		(3 << 8)
102 #define QUP_TAG_REC		(4 << 8)
103 #define QUP_BAM_INPUT_EOT		0x93
104 #define QUP_BAM_FLUSH_STOP		0x96
105 
106 /* QUP v2 tags */
107 #define QUP_TAG_V2_START               0x81
108 #define QUP_TAG_V2_DATAWR              0x82
109 #define QUP_TAG_V2_DATAWR_STOP         0x83
110 #define QUP_TAG_V2_DATARD              0x85
111 #define QUP_TAG_V2_DATARD_NACK         0x86
112 #define QUP_TAG_V2_DATARD_STOP         0x87
113 
114 /* Status, Error flags */
115 #define I2C_STATUS_WR_BUFFER_FULL	BIT(0)
116 #define I2C_STATUS_BUS_ACTIVE		BIT(8)
117 #define I2C_STATUS_ERROR_MASK		0x38000fc
118 #define QUP_STATUS_ERROR_FLAGS		0x7c
119 
120 #define QUP_READ_LIMIT			256
121 #define SET_BIT				0x1
122 #define RESET_BIT			0x0
123 #define ONE_BYTE			0x1
124 #define QUP_I2C_MX_CONFIG_DURING_RUN   BIT(31)
125 
126 /* Maximum transfer length for single DMA descriptor */
127 #define MX_TX_RX_LEN			SZ_64K
128 #define MX_BLOCKS			(MX_TX_RX_LEN / QUP_READ_LIMIT)
129 /* Maximum transfer length for all DMA descriptors */
130 #define MX_DMA_TX_RX_LEN		(2 * MX_TX_RX_LEN)
131 #define MX_DMA_BLOCKS			(MX_DMA_TX_RX_LEN / QUP_READ_LIMIT)
132 
133 /*
134  * Minimum transfer timeout for i2c transfers in seconds. It will be added on
135  * the top of maximum transfer time calculated from i2c bus speed to compensate
136  * the overheads.
137  */
138 #define TOUT_MIN			2
139 
140 /* Default values. Use these if FW query fails */
141 #define DEFAULT_CLK_FREQ I2C_MAX_STANDARD_MODE_FREQ
142 #define DEFAULT_SRC_CLK 20000000
143 
144 /*
145  * Max tags length (start, stop and maximum 2 bytes address) for each QUP
146  * data transfer
147  */
148 #define QUP_MAX_TAGS_LEN		4
149 /* Max data length for each DATARD tags */
150 #define RECV_MAX_DATA_LEN		254
151 /* TAG length for DATA READ in RX FIFO  */
152 #define READ_RX_TAGS_LEN		2
153 
154 #define QUP_BUS_WIDTH			8
155 
156 static unsigned int scl_freq;
157 module_param_named(scl_freq, scl_freq, uint, 0444);
158 MODULE_PARM_DESC(scl_freq, "SCL frequency override");
159 
160 /*
161  * count: no of blocks
162  * pos: current block number
163  * tx_tag_len: tx tag length for current block
164  * rx_tag_len: rx tag length for current block
165  * data_len: remaining data length for current message
166  * cur_blk_len: data length for current block
167  * total_tx_len: total tx length including tag bytes for current QUP transfer
168  * total_rx_len: total rx length including tag bytes for current QUP transfer
169  * tx_fifo_data_pos: current byte number in TX FIFO word
170  * tx_fifo_free: number of free bytes in current QUP block write.
171  * rx_fifo_data_pos: current byte number in RX FIFO word
172  * fifo_available: number of available bytes in RX FIFO for current
173  *		   QUP block read
174  * tx_fifo_data: QUP TX FIFO write works on word basis (4 bytes). New byte write
175  *		 to TX FIFO will be appended in this data and will be written to
176  *		 TX FIFO when all the 4 bytes are available.
177  * rx_fifo_data: QUP RX FIFO read works on word basis (4 bytes). This will
178  *		 contains the 4 bytes of RX data.
179  * cur_data: pointer to tell cur data position for current message
180  * cur_tx_tags: pointer to tell cur position in tags
181  * tx_tags_sent: all tx tag bytes have been written in FIFO word
182  * send_last_word: for tx FIFO, last word send is pending in current block
183  * rx_bytes_read: if all the bytes have been read from rx FIFO.
184  * rx_tags_fetched: all the rx tag bytes have been fetched from rx fifo word
185  * is_tx_blk_mode: whether tx uses block or FIFO mode in case of non BAM xfer.
186  * is_rx_blk_mode: whether rx uses block or FIFO mode in case of non BAM xfer.
187  * tags: contains tx tag bytes for current QUP transfer
188  */
189 struct qup_i2c_block {
190 	int		count;
191 	int		pos;
192 	int		tx_tag_len;
193 	int		rx_tag_len;
194 	int		data_len;
195 	int		cur_blk_len;
196 	int		total_tx_len;
197 	int		total_rx_len;
198 	int		tx_fifo_data_pos;
199 	int		tx_fifo_free;
200 	int		rx_fifo_data_pos;
201 	int		fifo_available;
202 	u32		tx_fifo_data;
203 	u32		rx_fifo_data;
204 	u8		*cur_data;
205 	u8		*cur_tx_tags;
206 	bool		tx_tags_sent;
207 	bool		send_last_word;
208 	bool		rx_tags_fetched;
209 	bool		rx_bytes_read;
210 	bool		is_tx_blk_mode;
211 	bool		is_rx_blk_mode;
212 	u8		tags[6];
213 };
214 
215 struct qup_i2c_tag {
216 	u8 *start;
217 	dma_addr_t addr;
218 };
219 
220 struct qup_i2c_bam {
221 	struct	qup_i2c_tag tag;
222 	struct	dma_chan *dma;
223 	struct	scatterlist *sg;
224 	unsigned int sg_cnt;
225 };
226 
227 struct qup_i2c_dev {
228 	struct device		*dev;
229 	void __iomem		*base;
230 	int			irq;
231 	struct clk		*clk;
232 	struct clk		*pclk;
233 	struct icc_path		*icc_path;
234 	struct i2c_adapter	adap;
235 
236 	int			clk_ctl;
237 	int			out_fifo_sz;
238 	int			in_fifo_sz;
239 	int			out_blk_sz;
240 	int			in_blk_sz;
241 
242 	int			blk_xfer_limit;
243 	unsigned long		one_byte_t;
244 	unsigned long		xfer_timeout;
245 	struct qup_i2c_block	blk;
246 
247 	struct i2c_msg		*msg;
248 	/* Current posion in user message buffer */
249 	int			pos;
250 	/* I2C protocol errors */
251 	u32			bus_err;
252 	/* QUP core errors */
253 	u32			qup_err;
254 
255 	/* To check if this is the last msg */
256 	bool			is_last;
257 	bool			is_smbus_read;
258 
259 	/* To configure when bus is in run state */
260 	u32			config_run;
261 
262 	/* bandwidth votes */
263 	u32			src_clk_freq;
264 	u32			cur_bw_clk_freq;
265 
266 	/* dma parameters */
267 	bool			is_dma;
268 	/* To check if the current transfer is using DMA */
269 	bool			use_dma;
270 	unsigned int		max_xfer_sg_len;
271 	unsigned int		tag_buf_pos;
272 	/* The threshold length above which block mode will be used */
273 	unsigned int		blk_mode_threshold;
274 	struct			dma_pool *dpool;
275 	struct			qup_i2c_tag start_tag;
276 	struct			qup_i2c_bam brx;
277 	struct			qup_i2c_bam btx;
278 
279 	struct completion	xfer;
280 	/* function to write data in tx fifo */
281 	void (*write_tx_fifo)(struct qup_i2c_dev *qup);
282 	/* function to read data from rx fifo */
283 	void (*read_rx_fifo)(struct qup_i2c_dev *qup);
284 	/* function to write tags in tx fifo for i2c read transfer */
285 	void (*write_rx_tags)(struct qup_i2c_dev *qup);
286 };
287 
qup_i2c_interrupt(int irq,void * dev)288 static irqreturn_t qup_i2c_interrupt(int irq, void *dev)
289 {
290 	struct qup_i2c_dev *qup = dev;
291 	struct qup_i2c_block *blk = &qup->blk;
292 	u32 bus_err;
293 	u32 qup_err;
294 	u32 opflags;
295 
296 	bus_err = readl(qup->base + QUP_I2C_STATUS);
297 	qup_err = readl(qup->base + QUP_ERROR_FLAGS);
298 	opflags = readl(qup->base + QUP_OPERATIONAL);
299 
300 	if (!qup->msg) {
301 		/* Clear Error interrupt */
302 		writel(QUP_RESET_STATE, qup->base + QUP_STATE);
303 		return IRQ_HANDLED;
304 	}
305 
306 	bus_err &= I2C_STATUS_ERROR_MASK;
307 	qup_err &= QUP_STATUS_ERROR_FLAGS;
308 
309 	/* Clear the error bits in QUP_ERROR_FLAGS */
310 	if (qup_err)
311 		writel(qup_err, qup->base + QUP_ERROR_FLAGS);
312 
313 	/* Clear the error bits in QUP_I2C_STATUS */
314 	if (bus_err)
315 		writel(bus_err, qup->base + QUP_I2C_STATUS);
316 
317 	/*
318 	 * Check for BAM mode and returns if already error has come for current
319 	 * transfer. In Error case, sometimes, QUP generates more than one
320 	 * interrupt.
321 	 */
322 	if (qup->use_dma && (qup->qup_err || qup->bus_err))
323 		return IRQ_HANDLED;
324 
325 	/* Reset the QUP State in case of error */
326 	if (qup_err || bus_err) {
327 		/*
328 		 * Don’t reset the QUP state in case of BAM mode. The BAM
329 		 * flush operation needs to be scheduled in transfer function
330 		 * which will clear the remaining schedule descriptors in BAM
331 		 * HW FIFO and generates the BAM interrupt.
332 		 */
333 		if (!qup->use_dma)
334 			writel(QUP_RESET_STATE, qup->base + QUP_STATE);
335 		goto done;
336 	}
337 
338 	if (opflags & QUP_OUT_SVC_FLAG) {
339 		writel(QUP_OUT_SVC_FLAG, qup->base + QUP_OPERATIONAL);
340 
341 		if (opflags & OUT_BLOCK_WRITE_REQ) {
342 			blk->tx_fifo_free += qup->out_blk_sz;
343 			if (qup->msg->flags & I2C_M_RD)
344 				qup->write_rx_tags(qup);
345 			else
346 				qup->write_tx_fifo(qup);
347 		}
348 	}
349 
350 	if (opflags & QUP_IN_SVC_FLAG) {
351 		writel(QUP_IN_SVC_FLAG, qup->base + QUP_OPERATIONAL);
352 
353 		if (!blk->is_rx_blk_mode) {
354 			blk->fifo_available += qup->in_fifo_sz;
355 			qup->read_rx_fifo(qup);
356 		} else if (opflags & IN_BLOCK_READ_REQ) {
357 			blk->fifo_available += qup->in_blk_sz;
358 			qup->read_rx_fifo(qup);
359 		}
360 	}
361 
362 	if (qup->msg->flags & I2C_M_RD) {
363 		if (!blk->rx_bytes_read)
364 			return IRQ_HANDLED;
365 	} else {
366 		/*
367 		 * Ideally, QUP_MAX_OUTPUT_DONE_FLAG should be checked
368 		 * for FIFO mode also. But, QUP_MAX_OUTPUT_DONE_FLAG lags
369 		 * behind QUP_OUTPUT_SERVICE_FLAG sometimes. The only reason
370 		 * of interrupt for write message in FIFO mode is
371 		 * QUP_MAX_OUTPUT_DONE_FLAG condition.
372 		 */
373 		if (blk->is_tx_blk_mode && !(opflags & QUP_MX_OUTPUT_DONE))
374 			return IRQ_HANDLED;
375 	}
376 
377 done:
378 	qup->qup_err = qup_err;
379 	qup->bus_err = bus_err;
380 	complete(&qup->xfer);
381 	return IRQ_HANDLED;
382 }
383 
qup_i2c_poll_state_mask(struct qup_i2c_dev * qup,u32 req_state,u32 req_mask)384 static int qup_i2c_poll_state_mask(struct qup_i2c_dev *qup,
385 				   u32 req_state, u32 req_mask)
386 {
387 	int retries = 1;
388 	u32 state;
389 
390 	/*
391 	 * State transition takes 3 AHB clocks cycles + 3 I2C master clock
392 	 * cycles. So retry once after a 1uS delay.
393 	 */
394 	do {
395 		state = readl(qup->base + QUP_STATE);
396 
397 		if (state & QUP_STATE_VALID &&
398 		    (state & req_mask) == req_state)
399 			return 0;
400 
401 		udelay(1);
402 	} while (retries--);
403 
404 	return -ETIMEDOUT;
405 }
406 
qup_i2c_poll_state(struct qup_i2c_dev * qup,u32 req_state)407 static int qup_i2c_poll_state(struct qup_i2c_dev *qup, u32 req_state)
408 {
409 	return qup_i2c_poll_state_mask(qup, req_state, QUP_STATE_MASK);
410 }
411 
qup_i2c_flush(struct qup_i2c_dev * qup)412 static void qup_i2c_flush(struct qup_i2c_dev *qup)
413 {
414 	u32 val = readl(qup->base + QUP_STATE);
415 
416 	val |= QUP_I2C_FLUSH;
417 	writel(val, qup->base + QUP_STATE);
418 }
419 
qup_i2c_poll_state_valid(struct qup_i2c_dev * qup)420 static int qup_i2c_poll_state_valid(struct qup_i2c_dev *qup)
421 {
422 	return qup_i2c_poll_state_mask(qup, 0, 0);
423 }
424 
qup_i2c_poll_state_i2c_master(struct qup_i2c_dev * qup)425 static int qup_i2c_poll_state_i2c_master(struct qup_i2c_dev *qup)
426 {
427 	return qup_i2c_poll_state_mask(qup, QUP_I2C_MAST_GEN, QUP_I2C_MAST_GEN);
428 }
429 
qup_i2c_change_state(struct qup_i2c_dev * qup,u32 state)430 static int qup_i2c_change_state(struct qup_i2c_dev *qup, u32 state)
431 {
432 	if (qup_i2c_poll_state_valid(qup) != 0)
433 		return -EIO;
434 
435 	writel(state, qup->base + QUP_STATE);
436 
437 	if (qup_i2c_poll_state(qup, state) != 0)
438 		return -EIO;
439 	return 0;
440 }
441 
442 /* Check if I2C bus returns to IDLE state */
qup_i2c_bus_active(struct qup_i2c_dev * qup,int len)443 static int qup_i2c_bus_active(struct qup_i2c_dev *qup, int len)
444 {
445 	unsigned long timeout;
446 	u32 status;
447 	int ret = 0;
448 
449 	timeout = jiffies + len * 4;
450 	for (;;) {
451 		status = readl(qup->base + QUP_I2C_STATUS);
452 		if (!(status & I2C_STATUS_BUS_ACTIVE))
453 			break;
454 
455 		if (time_after(jiffies, timeout)) {
456 			ret = -ETIMEDOUT;
457 			break;
458 		}
459 
460 		usleep_range(len, len * 2);
461 	}
462 
463 	return ret;
464 }
465 
qup_i2c_vote_bw(struct qup_i2c_dev * qup,u32 clk_freq)466 static int qup_i2c_vote_bw(struct qup_i2c_dev *qup, u32 clk_freq)
467 {
468 	u32 needed_peak_bw;
469 	int ret;
470 
471 	if (qup->cur_bw_clk_freq == clk_freq)
472 		return 0;
473 
474 	needed_peak_bw = Bps_to_icc(clk_freq * QUP_BUS_WIDTH);
475 	ret = icc_set_bw(qup->icc_path, 0, needed_peak_bw);
476 	if (ret)
477 		return ret;
478 
479 	qup->cur_bw_clk_freq = clk_freq;
480 	return 0;
481 }
482 
qup_i2c_write_tx_fifo_v1(struct qup_i2c_dev * qup)483 static void qup_i2c_write_tx_fifo_v1(struct qup_i2c_dev *qup)
484 {
485 	struct qup_i2c_block *blk = &qup->blk;
486 	struct i2c_msg *msg = qup->msg;
487 	u32 addr = i2c_8bit_addr_from_msg(msg);
488 	u32 qup_tag;
489 	int idx;
490 	u32 val;
491 
492 	if (qup->pos == 0) {
493 		val = QUP_TAG_START | addr;
494 		idx = 1;
495 		blk->tx_fifo_free--;
496 	} else {
497 		val = 0;
498 		idx = 0;
499 	}
500 
501 	while (blk->tx_fifo_free && qup->pos < msg->len) {
502 		if (qup->pos == msg->len - 1)
503 			qup_tag = QUP_TAG_STOP;
504 		else
505 			qup_tag = QUP_TAG_DATA;
506 
507 		if (idx & 1)
508 			val |= (qup_tag | msg->buf[qup->pos]) << QUP_MSW_SHIFT;
509 		else
510 			val = qup_tag | msg->buf[qup->pos];
511 
512 		/* Write out the pair and the last odd value */
513 		if (idx & 1 || qup->pos == msg->len - 1)
514 			writel(val, qup->base + QUP_OUT_FIFO_BASE);
515 
516 		qup->pos++;
517 		idx++;
518 		blk->tx_fifo_free--;
519 	}
520 }
521 
qup_i2c_set_blk_data(struct qup_i2c_dev * qup,struct i2c_msg * msg)522 static void qup_i2c_set_blk_data(struct qup_i2c_dev *qup,
523 				 struct i2c_msg *msg)
524 {
525 	qup->blk.pos = 0;
526 	qup->blk.data_len = msg->len;
527 	qup->blk.count = DIV_ROUND_UP(msg->len, qup->blk_xfer_limit);
528 }
529 
qup_i2c_get_data_len(struct qup_i2c_dev * qup)530 static int qup_i2c_get_data_len(struct qup_i2c_dev *qup)
531 {
532 	int data_len;
533 
534 	if (qup->blk.data_len > qup->blk_xfer_limit)
535 		data_len = qup->blk_xfer_limit;
536 	else
537 		data_len = qup->blk.data_len;
538 
539 	return data_len;
540 }
541 
qup_i2c_check_msg_len(struct i2c_msg * msg)542 static bool qup_i2c_check_msg_len(struct i2c_msg *msg)
543 {
544 	return ((msg->flags & I2C_M_RD) && (msg->flags & I2C_M_RECV_LEN));
545 }
546 
qup_i2c_set_tags_smb(u16 addr,u8 * tags,struct qup_i2c_dev * qup,struct i2c_msg * msg)547 static int qup_i2c_set_tags_smb(u16 addr, u8 *tags, struct qup_i2c_dev *qup,
548 			struct i2c_msg *msg)
549 {
550 	int len = 0;
551 
552 	if (qup->is_smbus_read) {
553 		tags[len++] = QUP_TAG_V2_DATARD_STOP;
554 		tags[len++] = qup_i2c_get_data_len(qup);
555 	} else {
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 		tags[len++] = QUP_TAG_V2_DATARD;
563 		/* Read 1 byte indicating the length of the SMBus message */
564 		tags[len++] = 1;
565 	}
566 	return len;
567 }
568 
qup_i2c_set_tags(u8 * tags,struct qup_i2c_dev * qup,struct i2c_msg * msg)569 static int qup_i2c_set_tags(u8 *tags, struct qup_i2c_dev *qup,
570 			    struct i2c_msg *msg)
571 {
572 	u16 addr = i2c_8bit_addr_from_msg(msg);
573 	int len = 0;
574 	int data_len;
575 
576 	int last = (qup->blk.pos == (qup->blk.count - 1)) && (qup->is_last);
577 
578 	/* Handle tags for SMBus block read */
579 	if (qup_i2c_check_msg_len(msg))
580 		return qup_i2c_set_tags_smb(addr, tags, qup, msg);
581 
582 	if (qup->blk.pos == 0) {
583 		tags[len++] = QUP_TAG_V2_START;
584 		tags[len++] = addr & 0xff;
585 
586 		if (msg->flags & I2C_M_TEN)
587 			tags[len++] = addr >> 8;
588 	}
589 
590 	/* Send _STOP commands for the last block */
591 	if (last) {
592 		if (msg->flags & I2C_M_RD)
593 			tags[len++] = QUP_TAG_V2_DATARD_STOP;
594 		else
595 			tags[len++] = QUP_TAG_V2_DATAWR_STOP;
596 	} else {
597 		if (msg->flags & I2C_M_RD)
598 			tags[len++] = qup->blk.pos == (qup->blk.count - 1) ?
599 				      QUP_TAG_V2_DATARD_NACK :
600 				      QUP_TAG_V2_DATARD;
601 		else
602 			tags[len++] = QUP_TAG_V2_DATAWR;
603 	}
604 
605 	data_len = qup_i2c_get_data_len(qup);
606 
607 	/* 0 implies 256 bytes */
608 	if (data_len == QUP_READ_LIMIT)
609 		tags[len++] = 0;
610 	else
611 		tags[len++] = data_len;
612 
613 	return len;
614 }
615 
616 
qup_i2c_bam_cb(void * data)617 static void qup_i2c_bam_cb(void *data)
618 {
619 	struct qup_i2c_dev *qup = data;
620 
621 	complete(&qup->xfer);
622 }
623 
qup_sg_set_buf(struct scatterlist * sg,void * buf,unsigned int buflen,struct qup_i2c_dev * qup,int dir)624 static int qup_sg_set_buf(struct scatterlist *sg, void *buf,
625 			  unsigned int buflen, struct qup_i2c_dev *qup,
626 			  int dir)
627 {
628 	int ret;
629 
630 	sg_set_buf(sg, buf, buflen);
631 	ret = dma_map_sg(qup->dev, sg, 1, dir);
632 	if (!ret)
633 		return -EINVAL;
634 
635 	return 0;
636 }
637 
qup_i2c_rel_dma(struct qup_i2c_dev * qup)638 static void qup_i2c_rel_dma(struct qup_i2c_dev *qup)
639 {
640 	if (qup->btx.dma)
641 		dma_release_channel(qup->btx.dma);
642 	if (qup->brx.dma)
643 		dma_release_channel(qup->brx.dma);
644 	qup->btx.dma = NULL;
645 	qup->brx.dma = NULL;
646 }
647 
qup_i2c_req_dma(struct qup_i2c_dev * qup)648 static int qup_i2c_req_dma(struct qup_i2c_dev *qup)
649 {
650 	int err;
651 
652 	if (!qup->btx.dma) {
653 		qup->btx.dma = dma_request_chan(qup->dev, "tx");
654 		if (IS_ERR(qup->btx.dma)) {
655 			err = PTR_ERR(qup->btx.dma);
656 			qup->btx.dma = NULL;
657 			dev_err(qup->dev, "\n tx channel not available");
658 			return err;
659 		}
660 	}
661 
662 	if (!qup->brx.dma) {
663 		qup->brx.dma = dma_request_chan(qup->dev, "rx");
664 		if (IS_ERR(qup->brx.dma)) {
665 			dev_err(qup->dev, "\n rx channel not available");
666 			err = PTR_ERR(qup->brx.dma);
667 			qup->brx.dma = NULL;
668 			qup_i2c_rel_dma(qup);
669 			return err;
670 		}
671 	}
672 	return 0;
673 }
674 
qup_i2c_bam_make_desc(struct qup_i2c_dev * qup,struct i2c_msg * msg)675 static int qup_i2c_bam_make_desc(struct qup_i2c_dev *qup, struct i2c_msg *msg)
676 {
677 	int ret = 0, limit = QUP_READ_LIMIT;
678 	u32 len = 0, blocks, rem;
679 	u32 i = 0, tlen, tx_len = 0;
680 	u8 *tags;
681 
682 	qup->blk_xfer_limit = QUP_READ_LIMIT;
683 	qup_i2c_set_blk_data(qup, msg);
684 
685 	blocks = qup->blk.count;
686 	rem = msg->len - (blocks - 1) * limit;
687 
688 	if (msg->flags & I2C_M_RD) {
689 		while (qup->blk.pos < blocks) {
690 			tlen = (i == (blocks - 1)) ? rem : limit;
691 			tags = &qup->start_tag.start[qup->tag_buf_pos + len];
692 			len += qup_i2c_set_tags(tags, qup, msg);
693 			qup->blk.data_len -= tlen;
694 
695 			/* scratch buf to read the start and len tags */
696 			ret = qup_sg_set_buf(&qup->brx.sg[qup->brx.sg_cnt++],
697 					     &qup->brx.tag.start[0],
698 					     2, qup, DMA_FROM_DEVICE);
699 
700 			if (ret)
701 				return ret;
702 
703 			ret = qup_sg_set_buf(&qup->brx.sg[qup->brx.sg_cnt++],
704 					     &msg->buf[limit * i],
705 					     tlen, qup,
706 					     DMA_FROM_DEVICE);
707 			if (ret)
708 				return ret;
709 
710 			i++;
711 			qup->blk.pos = i;
712 		}
713 		ret = qup_sg_set_buf(&qup->btx.sg[qup->btx.sg_cnt++],
714 				     &qup->start_tag.start[qup->tag_buf_pos],
715 				     len, qup, DMA_TO_DEVICE);
716 		if (ret)
717 			return ret;
718 
719 		qup->tag_buf_pos += len;
720 	} else {
721 		while (qup->blk.pos < blocks) {
722 			tlen = (i == (blocks - 1)) ? rem : limit;
723 			tags = &qup->start_tag.start[qup->tag_buf_pos + tx_len];
724 			len = qup_i2c_set_tags(tags, qup, msg);
725 			qup->blk.data_len -= tlen;
726 
727 			ret = qup_sg_set_buf(&qup->btx.sg[qup->btx.sg_cnt++],
728 					     tags, len,
729 					     qup, DMA_TO_DEVICE);
730 			if (ret)
731 				return ret;
732 
733 			tx_len += len;
734 			ret = qup_sg_set_buf(&qup->btx.sg[qup->btx.sg_cnt++],
735 					     &msg->buf[limit * i],
736 					     tlen, qup, DMA_TO_DEVICE);
737 			if (ret)
738 				return ret;
739 			i++;
740 			qup->blk.pos = i;
741 		}
742 
743 		qup->tag_buf_pos += tx_len;
744 	}
745 
746 	return 0;
747 }
748 
qup_i2c_bam_schedule_desc(struct qup_i2c_dev * qup)749 static int qup_i2c_bam_schedule_desc(struct qup_i2c_dev *qup)
750 {
751 	struct dma_async_tx_descriptor *txd, *rxd = NULL;
752 	int ret = 0;
753 	dma_cookie_t cookie_rx, cookie_tx;
754 	u32 len = 0;
755 	u32 tx_cnt = qup->btx.sg_cnt, rx_cnt = qup->brx.sg_cnt;
756 
757 	/* schedule the EOT and FLUSH I2C tags */
758 	len = 1;
759 	if (rx_cnt) {
760 		qup->btx.tag.start[0] = QUP_BAM_INPUT_EOT;
761 		len++;
762 
763 		/* scratch buf to read the BAM EOT FLUSH tags */
764 		ret = qup_sg_set_buf(&qup->brx.sg[rx_cnt++],
765 				     &qup->brx.tag.start[0],
766 				     1, qup, DMA_FROM_DEVICE);
767 		if (ret)
768 			return ret;
769 	}
770 
771 	qup->btx.tag.start[len - 1] = QUP_BAM_FLUSH_STOP;
772 	ret = qup_sg_set_buf(&qup->btx.sg[tx_cnt++], &qup->btx.tag.start[0],
773 			     len, qup, DMA_TO_DEVICE);
774 	if (ret)
775 		return ret;
776 
777 	txd = dmaengine_prep_slave_sg(qup->btx.dma, qup->btx.sg, tx_cnt,
778 				      DMA_MEM_TO_DEV,
779 				      DMA_PREP_INTERRUPT | DMA_PREP_FENCE);
780 	if (!txd) {
781 		dev_err(qup->dev, "failed to get tx desc\n");
782 		ret = -EINVAL;
783 		goto desc_err;
784 	}
785 
786 	if (!rx_cnt) {
787 		txd->callback = qup_i2c_bam_cb;
788 		txd->callback_param = qup;
789 	}
790 
791 	cookie_tx = dmaengine_submit(txd);
792 	if (dma_submit_error(cookie_tx)) {
793 		ret = -EINVAL;
794 		goto desc_err;
795 	}
796 
797 	dma_async_issue_pending(qup->btx.dma);
798 
799 	if (rx_cnt) {
800 		rxd = dmaengine_prep_slave_sg(qup->brx.dma, qup->brx.sg,
801 					      rx_cnt, DMA_DEV_TO_MEM,
802 					      DMA_PREP_INTERRUPT);
803 		if (!rxd) {
804 			dev_err(qup->dev, "failed to get rx desc\n");
805 			ret = -EINVAL;
806 
807 			/* abort TX descriptors */
808 			dmaengine_terminate_sync(qup->btx.dma);
809 			goto desc_err;
810 		}
811 
812 		rxd->callback = qup_i2c_bam_cb;
813 		rxd->callback_param = qup;
814 		cookie_rx = dmaengine_submit(rxd);
815 		if (dma_submit_error(cookie_rx)) {
816 			ret = -EINVAL;
817 			goto desc_err;
818 		}
819 
820 		dma_async_issue_pending(qup->brx.dma);
821 	}
822 
823 	if (!wait_for_completion_timeout(&qup->xfer, qup->xfer_timeout)) {
824 		dev_err(qup->dev, "normal trans timed out\n");
825 		ret = -ETIMEDOUT;
826 	}
827 
828 	if (ret || qup->bus_err || qup->qup_err) {
829 		reinit_completion(&qup->xfer);
830 
831 		ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
832 		if (ret) {
833 			dev_err(qup->dev, "change to run state timed out");
834 			goto desc_err;
835 		}
836 
837 		qup_i2c_flush(qup);
838 
839 		/* wait for remaining interrupts to occur */
840 		if (!wait_for_completion_timeout(&qup->xfer, HZ))
841 			dev_err(qup->dev, "flush timed out\n");
842 
843 		ret =  (qup->bus_err & QUP_I2C_NACK_FLAG) ? -ENXIO : -EIO;
844 	}
845 
846 desc_err:
847 	dma_unmap_sg(qup->dev, qup->btx.sg, tx_cnt, DMA_TO_DEVICE);
848 
849 	if (rx_cnt)
850 		dma_unmap_sg(qup->dev, qup->brx.sg, rx_cnt,
851 			     DMA_FROM_DEVICE);
852 
853 	return ret;
854 }
855 
qup_i2c_bam_clear_tag_buffers(struct qup_i2c_dev * qup)856 static void qup_i2c_bam_clear_tag_buffers(struct qup_i2c_dev *qup)
857 {
858 	qup->btx.sg_cnt = 0;
859 	qup->brx.sg_cnt = 0;
860 	qup->tag_buf_pos = 0;
861 }
862 
qup_i2c_bam_xfer(struct i2c_adapter * adap,struct i2c_msg * msg,int num)863 static int qup_i2c_bam_xfer(struct i2c_adapter *adap, struct i2c_msg *msg,
864 			    int num)
865 {
866 	struct qup_i2c_dev *qup = i2c_get_adapdata(adap);
867 	int ret = 0;
868 	int idx = 0;
869 
870 	ret = qup_i2c_vote_bw(qup, qup->src_clk_freq);
871 	if (ret)
872 		return ret;
873 
874 	enable_irq(qup->irq);
875 	ret = qup_i2c_req_dma(qup);
876 
877 	if (ret)
878 		goto out;
879 
880 	writel(0, qup->base + QUP_MX_INPUT_CNT);
881 	writel(0, qup->base + QUP_MX_OUTPUT_CNT);
882 
883 	/* set BAM mode */
884 	writel(QUP_REPACK_EN | QUP_BAM_MODE, qup->base + QUP_IO_MODE);
885 
886 	/* mask fifo irqs */
887 	writel((0x3 << 8), qup->base + QUP_OPERATIONAL_MASK);
888 
889 	/* set RUN STATE */
890 	ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
891 	if (ret)
892 		goto out;
893 
894 	writel(qup->clk_ctl, qup->base + QUP_I2C_CLK_CTL);
895 	qup_i2c_bam_clear_tag_buffers(qup);
896 
897 	for (idx = 0; idx < num; idx++) {
898 		qup->msg = msg + idx;
899 		qup->is_last = idx == (num - 1);
900 
901 		ret = qup_i2c_bam_make_desc(qup, qup->msg);
902 		if (ret)
903 			break;
904 
905 		/*
906 		 * Make DMA descriptor and schedule the BAM transfer if its
907 		 * already crossed the maximum length. Since the memory for all
908 		 * tags buffers have been taken for 2 maximum possible
909 		 * transfers length so it will never cross the buffer actual
910 		 * length.
911 		 */
912 		if (qup->btx.sg_cnt > qup->max_xfer_sg_len ||
913 		    qup->brx.sg_cnt > qup->max_xfer_sg_len ||
914 		    qup->is_last) {
915 			ret = qup_i2c_bam_schedule_desc(qup);
916 			if (ret)
917 				break;
918 
919 			qup_i2c_bam_clear_tag_buffers(qup);
920 		}
921 	}
922 
923 out:
924 	disable_irq(qup->irq);
925 
926 	qup->msg = NULL;
927 	return ret;
928 }
929 
qup_i2c_wait_for_complete(struct qup_i2c_dev * qup,struct i2c_msg * msg)930 static int qup_i2c_wait_for_complete(struct qup_i2c_dev *qup,
931 				     struct i2c_msg *msg)
932 {
933 	unsigned long left;
934 	int ret = 0;
935 
936 	left = wait_for_completion_timeout(&qup->xfer, qup->xfer_timeout);
937 	if (!left) {
938 		writel(1, qup->base + QUP_SW_RESET);
939 		ret = -ETIMEDOUT;
940 	}
941 
942 	if (qup->bus_err || qup->qup_err)
943 		ret =  (qup->bus_err & QUP_I2C_NACK_FLAG) ? -ENXIO : -EIO;
944 
945 	return ret;
946 }
947 
qup_i2c_read_rx_fifo_v1(struct qup_i2c_dev * qup)948 static void qup_i2c_read_rx_fifo_v1(struct qup_i2c_dev *qup)
949 {
950 	struct qup_i2c_block *blk = &qup->blk;
951 	struct i2c_msg *msg = qup->msg;
952 	u32 val = 0;
953 	int idx = 0;
954 
955 	while (blk->fifo_available && qup->pos < msg->len) {
956 		if ((idx & 1) == 0) {
957 			/* Reading 2 words at time */
958 			val = readl(qup->base + QUP_IN_FIFO_BASE);
959 			msg->buf[qup->pos++] = val & 0xFF;
960 		} else {
961 			msg->buf[qup->pos++] = val >> QUP_MSW_SHIFT;
962 		}
963 		idx++;
964 		blk->fifo_available--;
965 	}
966 
967 	if (qup->pos == msg->len)
968 		blk->rx_bytes_read = true;
969 }
970 
qup_i2c_write_rx_tags_v1(struct qup_i2c_dev * qup)971 static void qup_i2c_write_rx_tags_v1(struct qup_i2c_dev *qup)
972 {
973 	struct i2c_msg *msg = qup->msg;
974 	u32 addr, len, val;
975 
976 	addr = i2c_8bit_addr_from_msg(msg);
977 
978 	/* 0 is used to specify a length 256 (QUP_READ_LIMIT) */
979 	len = (msg->len == QUP_READ_LIMIT) ? 0 : msg->len;
980 
981 	val = ((QUP_TAG_REC | len) << QUP_MSW_SHIFT) | QUP_TAG_START | addr;
982 	writel(val, qup->base + QUP_OUT_FIFO_BASE);
983 }
984 
qup_i2c_conf_v1(struct qup_i2c_dev * qup)985 static void qup_i2c_conf_v1(struct qup_i2c_dev *qup)
986 {
987 	struct qup_i2c_block *blk = &qup->blk;
988 	u32 qup_config = I2C_MINI_CORE | I2C_N_VAL;
989 	u32 io_mode = QUP_REPACK_EN;
990 
991 	blk->is_tx_blk_mode = blk->total_tx_len > qup->out_fifo_sz;
992 	blk->is_rx_blk_mode = blk->total_rx_len > qup->in_fifo_sz;
993 
994 	if (blk->is_tx_blk_mode) {
995 		io_mode |= QUP_OUTPUT_BLK_MODE;
996 		writel(0, qup->base + QUP_MX_WRITE_CNT);
997 		writel(blk->total_tx_len, qup->base + QUP_MX_OUTPUT_CNT);
998 	} else {
999 		writel(0, qup->base + QUP_MX_OUTPUT_CNT);
1000 		writel(blk->total_tx_len, qup->base + QUP_MX_WRITE_CNT);
1001 	}
1002 
1003 	if (blk->total_rx_len) {
1004 		if (blk->is_rx_blk_mode) {
1005 			io_mode |= QUP_INPUT_BLK_MODE;
1006 			writel(0, qup->base + QUP_MX_READ_CNT);
1007 			writel(blk->total_rx_len, qup->base + QUP_MX_INPUT_CNT);
1008 		} else {
1009 			writel(0, qup->base + QUP_MX_INPUT_CNT);
1010 			writel(blk->total_rx_len, qup->base + QUP_MX_READ_CNT);
1011 		}
1012 	} else {
1013 		qup_config |= QUP_NO_INPUT;
1014 	}
1015 
1016 	writel(qup_config, qup->base + QUP_CONFIG);
1017 	writel(io_mode, qup->base + QUP_IO_MODE);
1018 }
1019 
qup_i2c_clear_blk_v1(struct qup_i2c_block * blk)1020 static void qup_i2c_clear_blk_v1(struct qup_i2c_block *blk)
1021 {
1022 	blk->tx_fifo_free = 0;
1023 	blk->fifo_available = 0;
1024 	blk->rx_bytes_read = false;
1025 }
1026 
qup_i2c_conf_xfer_v1(struct qup_i2c_dev * qup,bool is_rx)1027 static int qup_i2c_conf_xfer_v1(struct qup_i2c_dev *qup, bool is_rx)
1028 {
1029 	struct qup_i2c_block *blk = &qup->blk;
1030 	int ret;
1031 
1032 	qup_i2c_clear_blk_v1(blk);
1033 	qup_i2c_conf_v1(qup);
1034 	ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
1035 	if (ret)
1036 		return ret;
1037 
1038 	writel(qup->clk_ctl, qup->base + QUP_I2C_CLK_CTL);
1039 
1040 	ret = qup_i2c_change_state(qup, QUP_PAUSE_STATE);
1041 	if (ret)
1042 		return ret;
1043 
1044 	reinit_completion(&qup->xfer);
1045 	enable_irq(qup->irq);
1046 	if (!blk->is_tx_blk_mode) {
1047 		blk->tx_fifo_free = qup->out_fifo_sz;
1048 
1049 		if (is_rx)
1050 			qup_i2c_write_rx_tags_v1(qup);
1051 		else
1052 			qup_i2c_write_tx_fifo_v1(qup);
1053 	}
1054 
1055 	ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
1056 	if (ret)
1057 		goto err;
1058 
1059 	ret = qup_i2c_wait_for_complete(qup, qup->msg);
1060 	if (ret)
1061 		goto err;
1062 
1063 	ret = qup_i2c_bus_active(qup, ONE_BYTE);
1064 
1065 err:
1066 	disable_irq(qup->irq);
1067 	return ret;
1068 }
1069 
qup_i2c_write_one(struct qup_i2c_dev * qup)1070 static int qup_i2c_write_one(struct qup_i2c_dev *qup)
1071 {
1072 	struct i2c_msg *msg = qup->msg;
1073 	struct qup_i2c_block *blk = &qup->blk;
1074 
1075 	qup->pos = 0;
1076 	blk->total_tx_len = msg->len + 1;
1077 	blk->total_rx_len = 0;
1078 
1079 	return qup_i2c_conf_xfer_v1(qup, false);
1080 }
1081 
qup_i2c_read_one(struct qup_i2c_dev * qup)1082 static int qup_i2c_read_one(struct qup_i2c_dev *qup)
1083 {
1084 	struct qup_i2c_block *blk = &qup->blk;
1085 
1086 	qup->pos = 0;
1087 	blk->total_tx_len = 2;
1088 	blk->total_rx_len = qup->msg->len;
1089 
1090 	return qup_i2c_conf_xfer_v1(qup, true);
1091 }
1092 
qup_i2c_xfer(struct i2c_adapter * adap,struct i2c_msg msgs[],int num)1093 static int qup_i2c_xfer(struct i2c_adapter *adap,
1094 			struct i2c_msg msgs[],
1095 			int num)
1096 {
1097 	struct qup_i2c_dev *qup = i2c_get_adapdata(adap);
1098 	int ret, idx;
1099 
1100 	ret = pm_runtime_get_sync(qup->dev);
1101 	if (ret < 0)
1102 		goto out;
1103 
1104 	qup->bus_err = 0;
1105 	qup->qup_err = 0;
1106 
1107 	writel(1, qup->base + QUP_SW_RESET);
1108 	ret = qup_i2c_poll_state(qup, QUP_RESET_STATE);
1109 	if (ret)
1110 		goto out;
1111 
1112 	/* Configure QUP as I2C mini core */
1113 	writel(I2C_MINI_CORE | I2C_N_VAL, qup->base + QUP_CONFIG);
1114 
1115 	for (idx = 0; idx < num; idx++) {
1116 		if (qup_i2c_poll_state_i2c_master(qup)) {
1117 			ret = -EIO;
1118 			goto out;
1119 		}
1120 
1121 		if (qup_i2c_check_msg_len(&msgs[idx])) {
1122 			ret = -EINVAL;
1123 			goto out;
1124 		}
1125 
1126 		qup->msg = &msgs[idx];
1127 		if (msgs[idx].flags & I2C_M_RD)
1128 			ret = qup_i2c_read_one(qup);
1129 		else
1130 			ret = qup_i2c_write_one(qup);
1131 
1132 		if (ret)
1133 			break;
1134 
1135 		ret = qup_i2c_change_state(qup, QUP_RESET_STATE);
1136 		if (ret)
1137 			break;
1138 	}
1139 
1140 	if (ret == 0)
1141 		ret = num;
1142 out:
1143 
1144 	pm_runtime_mark_last_busy(qup->dev);
1145 	pm_runtime_put_autosuspend(qup->dev);
1146 
1147 	return ret;
1148 }
1149 
1150 /*
1151  * Configure registers related with reconfiguration during run and call it
1152  * before each i2c sub transfer.
1153  */
qup_i2c_conf_count_v2(struct qup_i2c_dev * qup)1154 static void qup_i2c_conf_count_v2(struct qup_i2c_dev *qup)
1155 {
1156 	struct qup_i2c_block *blk = &qup->blk;
1157 	u32 qup_config = I2C_MINI_CORE | I2C_N_VAL_V2;
1158 
1159 	if (blk->is_tx_blk_mode)
1160 		writel(qup->config_run | blk->total_tx_len,
1161 		       qup->base + QUP_MX_OUTPUT_CNT);
1162 	else
1163 		writel(qup->config_run | blk->total_tx_len,
1164 		       qup->base + QUP_MX_WRITE_CNT);
1165 
1166 	if (blk->total_rx_len) {
1167 		if (blk->is_rx_blk_mode)
1168 			writel(qup->config_run | blk->total_rx_len,
1169 			       qup->base + QUP_MX_INPUT_CNT);
1170 		else
1171 			writel(qup->config_run | blk->total_rx_len,
1172 			       qup->base + QUP_MX_READ_CNT);
1173 	} else {
1174 		qup_config |= QUP_NO_INPUT;
1175 	}
1176 
1177 	writel(qup_config, qup->base + QUP_CONFIG);
1178 }
1179 
1180 /*
1181  * Configure registers related with transfer mode (FIFO/Block)
1182  * before starting of i2c transfer. It will be called only once in
1183  * QUP RESET state.
1184  */
qup_i2c_conf_mode_v2(struct qup_i2c_dev * qup)1185 static void qup_i2c_conf_mode_v2(struct qup_i2c_dev *qup)
1186 {
1187 	struct qup_i2c_block *blk = &qup->blk;
1188 	u32 io_mode = QUP_REPACK_EN;
1189 
1190 	if (blk->is_tx_blk_mode) {
1191 		io_mode |= QUP_OUTPUT_BLK_MODE;
1192 		writel(0, qup->base + QUP_MX_WRITE_CNT);
1193 	} else {
1194 		writel(0, qup->base + QUP_MX_OUTPUT_CNT);
1195 	}
1196 
1197 	if (blk->is_rx_blk_mode) {
1198 		io_mode |= QUP_INPUT_BLK_MODE;
1199 		writel(0, qup->base + QUP_MX_READ_CNT);
1200 	} else {
1201 		writel(0, qup->base + QUP_MX_INPUT_CNT);
1202 	}
1203 
1204 	writel(io_mode, qup->base + QUP_IO_MODE);
1205 }
1206 
1207 /* Clear required variables before starting of any QUP v2 sub transfer. */
qup_i2c_clear_blk_v2(struct qup_i2c_block * blk)1208 static void qup_i2c_clear_blk_v2(struct qup_i2c_block *blk)
1209 {
1210 	blk->send_last_word = false;
1211 	blk->tx_tags_sent = false;
1212 	blk->tx_fifo_data = 0;
1213 	blk->tx_fifo_data_pos = 0;
1214 	blk->tx_fifo_free = 0;
1215 
1216 	blk->rx_tags_fetched = false;
1217 	blk->rx_bytes_read = false;
1218 	blk->rx_fifo_data = 0;
1219 	blk->rx_fifo_data_pos = 0;
1220 	blk->fifo_available = 0;
1221 }
1222 
1223 /* Receive data from RX FIFO for read message in QUP v2 i2c transfer. */
qup_i2c_recv_data(struct qup_i2c_dev * qup)1224 static void qup_i2c_recv_data(struct qup_i2c_dev *qup)
1225 {
1226 	struct qup_i2c_block *blk = &qup->blk;
1227 	int j;
1228 
1229 	for (j = blk->rx_fifo_data_pos;
1230 	     blk->cur_blk_len && blk->fifo_available;
1231 	     blk->cur_blk_len--, blk->fifo_available--) {
1232 		if (j == 0)
1233 			blk->rx_fifo_data = readl(qup->base + QUP_IN_FIFO_BASE);
1234 
1235 		*(blk->cur_data++) = blk->rx_fifo_data;
1236 		blk->rx_fifo_data >>= 8;
1237 
1238 		if (j == 3)
1239 			j = 0;
1240 		else
1241 			j++;
1242 	}
1243 
1244 	blk->rx_fifo_data_pos = j;
1245 }
1246 
1247 /* Receive tags for read message in QUP v2 i2c transfer. */
qup_i2c_recv_tags(struct qup_i2c_dev * qup)1248 static void qup_i2c_recv_tags(struct qup_i2c_dev *qup)
1249 {
1250 	struct qup_i2c_block *blk = &qup->blk;
1251 
1252 	blk->rx_fifo_data = readl(qup->base + QUP_IN_FIFO_BASE);
1253 	blk->rx_fifo_data >>= blk->rx_tag_len  * 8;
1254 	blk->rx_fifo_data_pos = blk->rx_tag_len;
1255 	blk->fifo_available -= blk->rx_tag_len;
1256 }
1257 
1258 /*
1259  * Read the data and tags from RX FIFO. Since in read case, the tags will be
1260  * preceded by received data bytes so
1261  * 1. Check if rx_tags_fetched is false i.e. the start of QUP block so receive
1262  *    all tag bytes and discard that.
1263  * 2. Read the data from RX FIFO. When all the data bytes have been read then
1264  *    set rx_bytes_read to true.
1265  */
qup_i2c_read_rx_fifo_v2(struct qup_i2c_dev * qup)1266 static void qup_i2c_read_rx_fifo_v2(struct qup_i2c_dev *qup)
1267 {
1268 	struct qup_i2c_block *blk = &qup->blk;
1269 
1270 	if (!blk->rx_tags_fetched) {
1271 		qup_i2c_recv_tags(qup);
1272 		blk->rx_tags_fetched = true;
1273 	}
1274 
1275 	qup_i2c_recv_data(qup);
1276 	if (!blk->cur_blk_len)
1277 		blk->rx_bytes_read = true;
1278 }
1279 
1280 /*
1281  * Write bytes in TX FIFO for write message in QUP v2 i2c transfer. QUP TX FIFO
1282  * write works on word basis (4 bytes). Append new data byte write for TX FIFO
1283  * in tx_fifo_data and write to TX FIFO when all the 4 bytes are present.
1284  */
1285 static void
qup_i2c_write_blk_data(struct qup_i2c_dev * qup,u8 ** data,unsigned int * len)1286 qup_i2c_write_blk_data(struct qup_i2c_dev *qup, u8 **data, unsigned int *len)
1287 {
1288 	struct qup_i2c_block *blk = &qup->blk;
1289 	unsigned int j;
1290 
1291 	for (j = blk->tx_fifo_data_pos; *len && blk->tx_fifo_free;
1292 	     (*len)--, blk->tx_fifo_free--) {
1293 		blk->tx_fifo_data |= *(*data)++ << (j * 8);
1294 		if (j == 3) {
1295 			writel(blk->tx_fifo_data,
1296 			       qup->base + QUP_OUT_FIFO_BASE);
1297 			blk->tx_fifo_data = 0x0;
1298 			j = 0;
1299 		} else {
1300 			j++;
1301 		}
1302 	}
1303 
1304 	blk->tx_fifo_data_pos = j;
1305 }
1306 
1307 /* Transfer tags for read message in QUP v2 i2c transfer. */
qup_i2c_write_rx_tags_v2(struct qup_i2c_dev * qup)1308 static void qup_i2c_write_rx_tags_v2(struct qup_i2c_dev *qup)
1309 {
1310 	struct qup_i2c_block *blk = &qup->blk;
1311 
1312 	qup_i2c_write_blk_data(qup, &blk->cur_tx_tags, &blk->tx_tag_len);
1313 	if (blk->tx_fifo_data_pos)
1314 		writel(blk->tx_fifo_data, qup->base + QUP_OUT_FIFO_BASE);
1315 }
1316 
1317 /*
1318  * Write the data and tags in TX FIFO. Since in write case, both tags and data
1319  * need to be written and QUP write tags can have maximum 256 data length, so
1320  *
1321  * 1. Check if tx_tags_sent is false i.e. the start of QUP block so write the
1322  *    tags to TX FIFO and set tx_tags_sent to true.
1323  * 2. Check if send_last_word is true. It will be set when last few data bytes
1324  *    (less than 4 bytes) are remaining to be written in FIFO because of no FIFO
1325  *    space. All this data bytes are available in tx_fifo_data so write this
1326  *    in FIFO.
1327  * 3. Write the data to TX FIFO and check for cur_blk_len. If it is non zero
1328  *    then more data is pending otherwise following 3 cases can be possible
1329  *    a. if tx_fifo_data_pos is zero i.e. all the data bytes in this block
1330  *       have been written in TX FIFO so nothing else is required.
1331  *    b. tx_fifo_free is non zero i.e tx FIFO is free so copy the remaining data
1332  *       from tx_fifo_data to tx FIFO. Since, qup_i2c_write_blk_data do write
1333  *	 in 4 bytes and FIFO space is in multiple of 4 bytes so tx_fifo_free
1334  *       will be always greater than or equal to 4 bytes.
1335  *    c. tx_fifo_free is zero. In this case, last few bytes (less than 4
1336  *       bytes) are copied to tx_fifo_data but couldn't be sent because of
1337  *       FIFO full so make send_last_word true.
1338  */
qup_i2c_write_tx_fifo_v2(struct qup_i2c_dev * qup)1339 static void qup_i2c_write_tx_fifo_v2(struct qup_i2c_dev *qup)
1340 {
1341 	struct qup_i2c_block *blk = &qup->blk;
1342 
1343 	if (!blk->tx_tags_sent) {
1344 		qup_i2c_write_blk_data(qup, &blk->cur_tx_tags,
1345 				       &blk->tx_tag_len);
1346 		blk->tx_tags_sent = true;
1347 	}
1348 
1349 	if (blk->send_last_word)
1350 		goto send_last_word;
1351 
1352 	qup_i2c_write_blk_data(qup, &blk->cur_data, &blk->cur_blk_len);
1353 	if (!blk->cur_blk_len) {
1354 		if (!blk->tx_fifo_data_pos)
1355 			return;
1356 
1357 		if (blk->tx_fifo_free)
1358 			goto send_last_word;
1359 
1360 		blk->send_last_word = true;
1361 	}
1362 
1363 	return;
1364 
1365 send_last_word:
1366 	writel(blk->tx_fifo_data, qup->base + QUP_OUT_FIFO_BASE);
1367 }
1368 
1369 /*
1370  * Main transfer function which read or write i2c data.
1371  * The QUP v2 supports reconfiguration during run in which multiple i2c sub
1372  * transfers can be scheduled.
1373  */
1374 static int
qup_i2c_conf_xfer_v2(struct qup_i2c_dev * qup,bool is_rx,bool is_first,bool change_pause_state)1375 qup_i2c_conf_xfer_v2(struct qup_i2c_dev *qup, bool is_rx, bool is_first,
1376 		     bool change_pause_state)
1377 {
1378 	struct qup_i2c_block *blk = &qup->blk;
1379 	struct i2c_msg *msg = qup->msg;
1380 	int ret;
1381 
1382 	/*
1383 	 * Check if its SMBus Block read for which the top level read will be
1384 	 * done into 2 QUP reads. One with message length 1 while other one is
1385 	 * with actual length.
1386 	 */
1387 	if (qup_i2c_check_msg_len(msg)) {
1388 		if (qup->is_smbus_read) {
1389 			/*
1390 			 * If the message length is already read in
1391 			 * the first byte of the buffer, account for
1392 			 * that by setting the offset
1393 			 */
1394 			blk->cur_data += 1;
1395 			is_first = false;
1396 		} else {
1397 			change_pause_state = false;
1398 		}
1399 	}
1400 
1401 	qup->config_run = is_first ? 0 : QUP_I2C_MX_CONFIG_DURING_RUN;
1402 
1403 	qup_i2c_clear_blk_v2(blk);
1404 	qup_i2c_conf_count_v2(qup);
1405 
1406 	/* If it is first sub transfer, then configure i2c bus clocks */
1407 	if (is_first) {
1408 		ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
1409 		if (ret)
1410 			return ret;
1411 
1412 		writel(qup->clk_ctl, qup->base + QUP_I2C_CLK_CTL);
1413 
1414 		ret = qup_i2c_change_state(qup, QUP_PAUSE_STATE);
1415 		if (ret)
1416 			return ret;
1417 	}
1418 
1419 	reinit_completion(&qup->xfer);
1420 	enable_irq(qup->irq);
1421 	/*
1422 	 * In FIFO mode, tx FIFO can be written directly while in block mode the
1423 	 * it will be written after getting OUT_BLOCK_WRITE_REQ interrupt
1424 	 */
1425 	if (!blk->is_tx_blk_mode) {
1426 		blk->tx_fifo_free = qup->out_fifo_sz;
1427 
1428 		if (is_rx)
1429 			qup_i2c_write_rx_tags_v2(qup);
1430 		else
1431 			qup_i2c_write_tx_fifo_v2(qup);
1432 	}
1433 
1434 	ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
1435 	if (ret)
1436 		goto err;
1437 
1438 	ret = qup_i2c_wait_for_complete(qup, msg);
1439 	if (ret)
1440 		goto err;
1441 
1442 	/* Move to pause state for all the transfers, except last one */
1443 	if (change_pause_state) {
1444 		ret = qup_i2c_change_state(qup, QUP_PAUSE_STATE);
1445 		if (ret)
1446 			goto err;
1447 	}
1448 
1449 err:
1450 	disable_irq(qup->irq);
1451 	return ret;
1452 }
1453 
1454 /*
1455  * Transfer one read/write message in i2c transfer. It splits the message into
1456  * multiple of blk_xfer_limit data length blocks and schedule each
1457  * QUP block individually.
1458  */
qup_i2c_xfer_v2_msg(struct qup_i2c_dev * qup,int msg_id,bool is_rx)1459 static int qup_i2c_xfer_v2_msg(struct qup_i2c_dev *qup, int msg_id, bool is_rx)
1460 {
1461 	int ret = 0;
1462 	unsigned int data_len, i;
1463 	struct i2c_msg *msg = qup->msg;
1464 	struct qup_i2c_block *blk = &qup->blk;
1465 	u8 *msg_buf = msg->buf;
1466 
1467 	qup->blk_xfer_limit = is_rx ? RECV_MAX_DATA_LEN : QUP_READ_LIMIT;
1468 	qup_i2c_set_blk_data(qup, msg);
1469 
1470 	for (i = 0; i < blk->count; i++) {
1471 		data_len =  qup_i2c_get_data_len(qup);
1472 		blk->pos = i;
1473 		blk->cur_tx_tags = blk->tags;
1474 		blk->cur_blk_len = data_len;
1475 		blk->tx_tag_len =
1476 			qup_i2c_set_tags(blk->cur_tx_tags, qup, qup->msg);
1477 
1478 		blk->cur_data = msg_buf;
1479 
1480 		if (is_rx) {
1481 			blk->total_tx_len = blk->tx_tag_len;
1482 			blk->rx_tag_len = 2;
1483 			blk->total_rx_len = blk->rx_tag_len + data_len;
1484 		} else {
1485 			blk->total_tx_len = blk->tx_tag_len + data_len;
1486 			blk->total_rx_len = 0;
1487 		}
1488 
1489 		ret = qup_i2c_conf_xfer_v2(qup, is_rx, !msg_id && !i,
1490 					   !qup->is_last || i < blk->count - 1);
1491 		if (ret)
1492 			return ret;
1493 
1494 		/* Handle SMBus block read length */
1495 		if (qup_i2c_check_msg_len(msg) && msg->len == 1 &&
1496 		    !qup->is_smbus_read) {
1497 			if (msg->buf[0] > I2C_SMBUS_BLOCK_MAX)
1498 				return -EPROTO;
1499 
1500 			msg->len = msg->buf[0];
1501 			qup->is_smbus_read = true;
1502 			ret = qup_i2c_xfer_v2_msg(qup, msg_id, true);
1503 			qup->is_smbus_read = false;
1504 			if (ret)
1505 				return ret;
1506 
1507 			msg->len += 1;
1508 		}
1509 
1510 		msg_buf += data_len;
1511 		blk->data_len -= qup->blk_xfer_limit;
1512 	}
1513 
1514 	return ret;
1515 }
1516 
1517 /*
1518  * QUP v2 supports 3 modes
1519  * Programmed IO using FIFO mode : Less than FIFO size
1520  * Programmed IO using Block mode : Greater than FIFO size
1521  * DMA using BAM : Appropriate for any transaction size but the address should
1522  *		   be DMA applicable
1523  *
1524  * This function determines the mode which will be used for this transfer. An
1525  * i2c transfer contains multiple message. Following are the rules to determine
1526  * the mode used.
1527  * 1. Determine complete length, maximum tx and rx length for complete transfer.
1528  * 2. If complete transfer length is greater than fifo size then use the DMA
1529  *    mode.
1530  * 3. In FIFO or block mode, tx and rx can operate in different mode so check
1531  *    for maximum tx and rx length to determine mode.
1532  */
1533 static int
qup_i2c_determine_mode_v2(struct qup_i2c_dev * qup,struct i2c_msg msgs[],int num)1534 qup_i2c_determine_mode_v2(struct qup_i2c_dev *qup,
1535 			  struct i2c_msg msgs[], int num)
1536 {
1537 	int idx;
1538 	bool no_dma = false;
1539 	unsigned int max_tx_len = 0, max_rx_len = 0, total_len = 0;
1540 
1541 	/* All i2c_msgs should be transferred using either dma or cpu */
1542 	for (idx = 0; idx < num; idx++) {
1543 		if (msgs[idx].flags & I2C_M_RD)
1544 			max_rx_len = max_t(unsigned int, max_rx_len,
1545 					   msgs[idx].len);
1546 		else
1547 			max_tx_len = max_t(unsigned int, max_tx_len,
1548 					   msgs[idx].len);
1549 
1550 		if (is_vmalloc_addr(msgs[idx].buf))
1551 			no_dma = true;
1552 
1553 		total_len += msgs[idx].len;
1554 	}
1555 
1556 	if (!no_dma && qup->is_dma &&
1557 	    (total_len > qup->out_fifo_sz || total_len > qup->in_fifo_sz)) {
1558 		qup->use_dma = true;
1559 	} else {
1560 		qup->blk.is_tx_blk_mode = max_tx_len > qup->out_fifo_sz -
1561 			QUP_MAX_TAGS_LEN;
1562 		qup->blk.is_rx_blk_mode = max_rx_len > qup->in_fifo_sz -
1563 			READ_RX_TAGS_LEN;
1564 	}
1565 
1566 	return 0;
1567 }
1568 
qup_i2c_xfer_v2(struct i2c_adapter * adap,struct i2c_msg msgs[],int num)1569 static int qup_i2c_xfer_v2(struct i2c_adapter *adap,
1570 			   struct i2c_msg msgs[],
1571 			   int num)
1572 {
1573 	struct qup_i2c_dev *qup = i2c_get_adapdata(adap);
1574 	int ret, idx = 0;
1575 
1576 	qup->bus_err = 0;
1577 	qup->qup_err = 0;
1578 
1579 	ret = pm_runtime_get_sync(qup->dev);
1580 	if (ret < 0)
1581 		goto out;
1582 
1583 	ret = qup_i2c_determine_mode_v2(qup, msgs, num);
1584 	if (ret)
1585 		goto out;
1586 
1587 	writel(1, qup->base + QUP_SW_RESET);
1588 	ret = qup_i2c_poll_state(qup, QUP_RESET_STATE);
1589 	if (ret)
1590 		goto out;
1591 
1592 	/* Configure QUP as I2C mini core */
1593 	writel(I2C_MINI_CORE | I2C_N_VAL_V2, qup->base + QUP_CONFIG);
1594 	writel(QUP_V2_TAGS_EN, qup->base + QUP_I2C_MASTER_GEN);
1595 
1596 	if (qup_i2c_poll_state_i2c_master(qup)) {
1597 		ret = -EIO;
1598 		goto out;
1599 	}
1600 
1601 	if (qup->use_dma) {
1602 		reinit_completion(&qup->xfer);
1603 		ret = qup_i2c_bam_xfer(adap, &msgs[0], num);
1604 		qup->use_dma = false;
1605 	} else {
1606 		qup_i2c_conf_mode_v2(qup);
1607 
1608 		for (idx = 0; idx < num; idx++) {
1609 			qup->msg = &msgs[idx];
1610 			qup->is_last = idx == (num - 1);
1611 
1612 			ret = qup_i2c_xfer_v2_msg(qup, idx,
1613 					!!(msgs[idx].flags & I2C_M_RD));
1614 			if (ret)
1615 				break;
1616 		}
1617 		qup->msg = NULL;
1618 	}
1619 
1620 	if (!ret)
1621 		ret = qup_i2c_bus_active(qup, ONE_BYTE);
1622 
1623 	if (!ret)
1624 		qup_i2c_change_state(qup, QUP_RESET_STATE);
1625 
1626 	if (ret == 0)
1627 		ret = num;
1628 out:
1629 	pm_runtime_mark_last_busy(qup->dev);
1630 	pm_runtime_put_autosuspend(qup->dev);
1631 
1632 	return ret;
1633 }
1634 
qup_i2c_func(struct i2c_adapter * adap)1635 static u32 qup_i2c_func(struct i2c_adapter *adap)
1636 {
1637 	return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL_ALL & ~I2C_FUNC_SMBUS_QUICK);
1638 }
1639 
1640 static const struct i2c_algorithm qup_i2c_algo = {
1641 	.master_xfer	= qup_i2c_xfer,
1642 	.functionality	= qup_i2c_func,
1643 };
1644 
1645 static const struct i2c_algorithm qup_i2c_algo_v2 = {
1646 	.master_xfer	= qup_i2c_xfer_v2,
1647 	.functionality	= qup_i2c_func,
1648 };
1649 
1650 /*
1651  * The QUP block will issue a NACK and STOP on the bus when reaching
1652  * the end of the read, the length of the read is specified as one byte
1653  * which limits the possible read to 256 (QUP_READ_LIMIT) bytes.
1654  */
1655 static const struct i2c_adapter_quirks qup_i2c_quirks = {
1656 	.flags = I2C_AQ_NO_ZERO_LEN,
1657 	.max_read_len = QUP_READ_LIMIT,
1658 };
1659 
1660 static const struct i2c_adapter_quirks qup_i2c_quirks_v2 = {
1661 	.flags = I2C_AQ_NO_ZERO_LEN,
1662 };
1663 
qup_i2c_enable_clocks(struct qup_i2c_dev * qup)1664 static void qup_i2c_enable_clocks(struct qup_i2c_dev *qup)
1665 {
1666 	clk_prepare_enable(qup->clk);
1667 	clk_prepare_enable(qup->pclk);
1668 }
1669 
qup_i2c_disable_clocks(struct qup_i2c_dev * qup)1670 static void qup_i2c_disable_clocks(struct qup_i2c_dev *qup)
1671 {
1672 	u32 config;
1673 
1674 	qup_i2c_change_state(qup, QUP_RESET_STATE);
1675 	clk_disable_unprepare(qup->clk);
1676 	config = readl(qup->base + QUP_CONFIG);
1677 	config |= QUP_CLOCK_AUTO_GATE;
1678 	writel(config, qup->base + QUP_CONFIG);
1679 	qup_i2c_vote_bw(qup, 0);
1680 	clk_disable_unprepare(qup->pclk);
1681 }
1682 
1683 static const struct acpi_device_id qup_i2c_acpi_match[] = {
1684 	{ "QCOM8010"},
1685 	{ },
1686 };
1687 MODULE_DEVICE_TABLE(acpi, qup_i2c_acpi_match);
1688 
qup_i2c_probe(struct platform_device * pdev)1689 static int qup_i2c_probe(struct platform_device *pdev)
1690 {
1691 	static const int blk_sizes[] = {4, 16, 32};
1692 	struct qup_i2c_dev *qup;
1693 	unsigned long one_bit_t;
1694 	u32 io_mode, hw_ver, size;
1695 	int ret, fs_div, hs_div;
1696 	u32 src_clk_freq = DEFAULT_SRC_CLK;
1697 	u32 clk_freq = DEFAULT_CLK_FREQ;
1698 	int blocks;
1699 	bool is_qup_v1;
1700 
1701 	qup = devm_kzalloc(&pdev->dev, sizeof(*qup), GFP_KERNEL);
1702 	if (!qup)
1703 		return -ENOMEM;
1704 
1705 	qup->dev = &pdev->dev;
1706 	init_completion(&qup->xfer);
1707 	platform_set_drvdata(pdev, qup);
1708 
1709 	if (scl_freq) {
1710 		dev_notice(qup->dev, "Using override frequency of %u\n", scl_freq);
1711 		clk_freq = scl_freq;
1712 	} else {
1713 		ret = device_property_read_u32(qup->dev, "clock-frequency", &clk_freq);
1714 		if (ret) {
1715 			dev_notice(qup->dev, "using default clock-frequency %d",
1716 				DEFAULT_CLK_FREQ);
1717 		}
1718 	}
1719 
1720 	if (of_device_is_compatible(pdev->dev.of_node, "qcom,i2c-qup-v1.1.1")) {
1721 		qup->adap.algo = &qup_i2c_algo;
1722 		qup->adap.quirks = &qup_i2c_quirks;
1723 		is_qup_v1 = true;
1724 	} else {
1725 		qup->adap.algo = &qup_i2c_algo_v2;
1726 		qup->adap.quirks = &qup_i2c_quirks_v2;
1727 		is_qup_v1 = false;
1728 		if (acpi_match_device(qup_i2c_acpi_match, qup->dev))
1729 			goto nodma;
1730 		else
1731 			ret = qup_i2c_req_dma(qup);
1732 
1733 		if (ret == -EPROBE_DEFER)
1734 			goto fail_dma;
1735 		else if (ret != 0)
1736 			goto nodma;
1737 
1738 		qup->max_xfer_sg_len = (MX_BLOCKS << 1);
1739 		blocks = (MX_DMA_BLOCKS << 1) + 1;
1740 		qup->btx.sg = devm_kcalloc(&pdev->dev,
1741 					   blocks, sizeof(*qup->btx.sg),
1742 					   GFP_KERNEL);
1743 		if (!qup->btx.sg) {
1744 			ret = -ENOMEM;
1745 			goto fail_dma;
1746 		}
1747 		sg_init_table(qup->btx.sg, blocks);
1748 
1749 		qup->brx.sg = devm_kcalloc(&pdev->dev,
1750 					   blocks, sizeof(*qup->brx.sg),
1751 					   GFP_KERNEL);
1752 		if (!qup->brx.sg) {
1753 			ret = -ENOMEM;
1754 			goto fail_dma;
1755 		}
1756 		sg_init_table(qup->brx.sg, blocks);
1757 
1758 		/* 2 tag bytes for each block + 5 for start, stop tags */
1759 		size = blocks * 2 + 5;
1760 
1761 		qup->start_tag.start = devm_kzalloc(&pdev->dev,
1762 						    size, GFP_KERNEL);
1763 		if (!qup->start_tag.start) {
1764 			ret = -ENOMEM;
1765 			goto fail_dma;
1766 		}
1767 
1768 		qup->brx.tag.start = devm_kzalloc(&pdev->dev, 2, GFP_KERNEL);
1769 		if (!qup->brx.tag.start) {
1770 			ret = -ENOMEM;
1771 			goto fail_dma;
1772 		}
1773 
1774 		qup->btx.tag.start = devm_kzalloc(&pdev->dev, 2, GFP_KERNEL);
1775 		if (!qup->btx.tag.start) {
1776 			ret = -ENOMEM;
1777 			goto fail_dma;
1778 		}
1779 		qup->is_dma = true;
1780 
1781 		qup->icc_path = devm_of_icc_get(&pdev->dev, NULL);
1782 		if (IS_ERR(qup->icc_path))
1783 			return dev_err_probe(&pdev->dev, PTR_ERR(qup->icc_path),
1784 					     "failed to get interconnect path\n");
1785 	}
1786 
1787 nodma:
1788 	/* We support frequencies up to FAST Mode Plus (1MHz) */
1789 	if (!clk_freq || clk_freq > I2C_MAX_FAST_MODE_PLUS_FREQ) {
1790 		dev_err(qup->dev, "clock frequency not supported %d\n",
1791 			clk_freq);
1792 		ret = -EINVAL;
1793 		goto fail_dma;
1794 	}
1795 
1796 	qup->base = devm_platform_ioremap_resource(pdev, 0);
1797 	if (IS_ERR(qup->base)) {
1798 		ret = PTR_ERR(qup->base);
1799 		goto fail_dma;
1800 	}
1801 
1802 	qup->irq = platform_get_irq(pdev, 0);
1803 	if (qup->irq < 0) {
1804 		ret = qup->irq;
1805 		goto fail_dma;
1806 	}
1807 
1808 	if (has_acpi_companion(qup->dev)) {
1809 		ret = device_property_read_u32(qup->dev,
1810 				"src-clock-hz", &src_clk_freq);
1811 		if (ret) {
1812 			dev_notice(qup->dev, "using default src-clock-hz %d",
1813 				DEFAULT_SRC_CLK);
1814 		}
1815 		ACPI_COMPANION_SET(&qup->adap.dev, ACPI_COMPANION(qup->dev));
1816 	} else {
1817 		qup->clk = devm_clk_get(qup->dev, "core");
1818 		if (IS_ERR(qup->clk)) {
1819 			dev_err(qup->dev, "Could not get core clock\n");
1820 			ret = PTR_ERR(qup->clk);
1821 			goto fail_dma;
1822 		}
1823 
1824 		qup->pclk = devm_clk_get(qup->dev, "iface");
1825 		if (IS_ERR(qup->pclk)) {
1826 			dev_err(qup->dev, "Could not get iface clock\n");
1827 			ret = PTR_ERR(qup->pclk);
1828 			goto fail_dma;
1829 		}
1830 		qup_i2c_enable_clocks(qup);
1831 		src_clk_freq = clk_get_rate(qup->clk);
1832 	}
1833 	qup->src_clk_freq = src_clk_freq;
1834 
1835 	/*
1836 	 * Bootloaders might leave a pending interrupt on certain QUP's,
1837 	 * so we reset the core before registering for interrupts.
1838 	 */
1839 	writel(1, qup->base + QUP_SW_RESET);
1840 	ret = qup_i2c_poll_state_valid(qup);
1841 	if (ret)
1842 		goto fail;
1843 
1844 	ret = devm_request_irq(qup->dev, qup->irq, qup_i2c_interrupt,
1845 			       IRQF_TRIGGER_HIGH | IRQF_NO_AUTOEN,
1846 			       "i2c_qup", qup);
1847 	if (ret) {
1848 		dev_err(qup->dev, "Request %d IRQ failed\n", qup->irq);
1849 		goto fail;
1850 	}
1851 
1852 	hw_ver = readl(qup->base + QUP_HW_VERSION);
1853 	dev_dbg(qup->dev, "Revision %x\n", hw_ver);
1854 
1855 	io_mode = readl(qup->base + QUP_IO_MODE);
1856 
1857 	/*
1858 	 * The block/fifo size w.r.t. 'actual data' is 1/2 due to 'tag'
1859 	 * associated with each byte written/received
1860 	 */
1861 	size = QUP_OUTPUT_BLOCK_SIZE(io_mode);
1862 	if (size >= ARRAY_SIZE(blk_sizes)) {
1863 		ret = -EIO;
1864 		goto fail;
1865 	}
1866 	qup->out_blk_sz = blk_sizes[size];
1867 
1868 	size = QUP_INPUT_BLOCK_SIZE(io_mode);
1869 	if (size >= ARRAY_SIZE(blk_sizes)) {
1870 		ret = -EIO;
1871 		goto fail;
1872 	}
1873 	qup->in_blk_sz = blk_sizes[size];
1874 
1875 	if (is_qup_v1) {
1876 		/*
1877 		 * in QUP v1, QUP_CONFIG uses N as 15 i.e 16 bits constitutes a
1878 		 * single transfer but the block size is in bytes so divide the
1879 		 * in_blk_sz and out_blk_sz by 2
1880 		 */
1881 		qup->in_blk_sz /= 2;
1882 		qup->out_blk_sz /= 2;
1883 		qup->write_tx_fifo = qup_i2c_write_tx_fifo_v1;
1884 		qup->read_rx_fifo = qup_i2c_read_rx_fifo_v1;
1885 		qup->write_rx_tags = qup_i2c_write_rx_tags_v1;
1886 	} else {
1887 		qup->write_tx_fifo = qup_i2c_write_tx_fifo_v2;
1888 		qup->read_rx_fifo = qup_i2c_read_rx_fifo_v2;
1889 		qup->write_rx_tags = qup_i2c_write_rx_tags_v2;
1890 	}
1891 
1892 	size = QUP_OUTPUT_FIFO_SIZE(io_mode);
1893 	qup->out_fifo_sz = qup->out_blk_sz * (2 << size);
1894 
1895 	size = QUP_INPUT_FIFO_SIZE(io_mode);
1896 	qup->in_fifo_sz = qup->in_blk_sz * (2 << size);
1897 
1898 	hs_div = 3;
1899 	if (clk_freq <= I2C_MAX_STANDARD_MODE_FREQ) {
1900 		fs_div = ((src_clk_freq / clk_freq) / 2) - 3;
1901 		qup->clk_ctl = (hs_div << 8) | (fs_div & 0xff);
1902 	} else {
1903 		/* 33%/66% duty cycle */
1904 		fs_div = ((src_clk_freq / clk_freq) - 6) * 2 / 3;
1905 		qup->clk_ctl = ((fs_div / 2) << 16) | (hs_div << 8) | (fs_div & 0xff);
1906 	}
1907 
1908 	/*
1909 	 * Time it takes for a byte to be clocked out on the bus.
1910 	 * Each byte takes 9 clock cycles (8 bits + 1 ack).
1911 	 */
1912 	one_bit_t = (USEC_PER_SEC / clk_freq) + 1;
1913 	qup->one_byte_t = one_bit_t * 9;
1914 	qup->xfer_timeout = TOUT_MIN * HZ +
1915 		usecs_to_jiffies(MX_DMA_TX_RX_LEN * qup->one_byte_t);
1916 
1917 	dev_dbg(qup->dev, "IN:block:%d, fifo:%d, OUT:block:%d, fifo:%d\n",
1918 		qup->in_blk_sz, qup->in_fifo_sz,
1919 		qup->out_blk_sz, qup->out_fifo_sz);
1920 
1921 	i2c_set_adapdata(&qup->adap, qup);
1922 	qup->adap.dev.parent = qup->dev;
1923 	qup->adap.dev.of_node = pdev->dev.of_node;
1924 	qup->is_last = true;
1925 
1926 	strscpy(qup->adap.name, "QUP I2C adapter", sizeof(qup->adap.name));
1927 
1928 	pm_runtime_set_autosuspend_delay(qup->dev, MSEC_PER_SEC);
1929 	pm_runtime_use_autosuspend(qup->dev);
1930 	pm_runtime_set_active(qup->dev);
1931 	pm_runtime_enable(qup->dev);
1932 
1933 	ret = i2c_add_adapter(&qup->adap);
1934 	if (ret)
1935 		goto fail_runtime;
1936 
1937 	return 0;
1938 
1939 fail_runtime:
1940 	pm_runtime_disable(qup->dev);
1941 	pm_runtime_set_suspended(qup->dev);
1942 fail:
1943 	qup_i2c_disable_clocks(qup);
1944 fail_dma:
1945 	if (qup->btx.dma)
1946 		dma_release_channel(qup->btx.dma);
1947 	if (qup->brx.dma)
1948 		dma_release_channel(qup->brx.dma);
1949 	return ret;
1950 }
1951 
qup_i2c_remove(struct platform_device * pdev)1952 static void qup_i2c_remove(struct platform_device *pdev)
1953 {
1954 	struct qup_i2c_dev *qup = platform_get_drvdata(pdev);
1955 
1956 	if (qup->is_dma) {
1957 		dma_release_channel(qup->btx.dma);
1958 		dma_release_channel(qup->brx.dma);
1959 	}
1960 
1961 	disable_irq(qup->irq);
1962 	qup_i2c_disable_clocks(qup);
1963 	i2c_del_adapter(&qup->adap);
1964 	pm_runtime_disable(qup->dev);
1965 	pm_runtime_set_suspended(qup->dev);
1966 }
1967 
qup_i2c_pm_suspend_runtime(struct device * device)1968 static int qup_i2c_pm_suspend_runtime(struct device *device)
1969 {
1970 	struct qup_i2c_dev *qup = dev_get_drvdata(device);
1971 
1972 	dev_dbg(device, "pm_runtime: suspending...\n");
1973 	qup_i2c_disable_clocks(qup);
1974 	return 0;
1975 }
1976 
qup_i2c_pm_resume_runtime(struct device * device)1977 static int qup_i2c_pm_resume_runtime(struct device *device)
1978 {
1979 	struct qup_i2c_dev *qup = dev_get_drvdata(device);
1980 
1981 	dev_dbg(device, "pm_runtime: resuming...\n");
1982 	qup_i2c_enable_clocks(qup);
1983 	return 0;
1984 }
1985 
qup_i2c_suspend(struct device * device)1986 static int qup_i2c_suspend(struct device *device)
1987 {
1988 	if (!pm_runtime_suspended(device))
1989 		return qup_i2c_pm_suspend_runtime(device);
1990 	return 0;
1991 }
1992 
qup_i2c_resume(struct device * device)1993 static int qup_i2c_resume(struct device *device)
1994 {
1995 	qup_i2c_pm_resume_runtime(device);
1996 	pm_runtime_mark_last_busy(device);
1997 	pm_request_autosuspend(device);
1998 	return 0;
1999 }
2000 
2001 static const struct dev_pm_ops qup_i2c_qup_pm_ops = {
2002 	SYSTEM_SLEEP_PM_OPS(qup_i2c_suspend, qup_i2c_resume)
2003 	RUNTIME_PM_OPS(qup_i2c_pm_suspend_runtime,
2004 		       qup_i2c_pm_resume_runtime, NULL)
2005 };
2006 
2007 static const struct of_device_id qup_i2c_dt_match[] = {
2008 	{ .compatible = "qcom,i2c-qup-v1.1.1" },
2009 	{ .compatible = "qcom,i2c-qup-v2.1.1" },
2010 	{ .compatible = "qcom,i2c-qup-v2.2.1" },
2011 	{}
2012 };
2013 MODULE_DEVICE_TABLE(of, qup_i2c_dt_match);
2014 
2015 static struct platform_driver qup_i2c_driver = {
2016 	.probe  = qup_i2c_probe,
2017 	.remove_new = qup_i2c_remove,
2018 	.driver = {
2019 		.name = "i2c_qup",
2020 		.pm = pm_ptr(&qup_i2c_qup_pm_ops),
2021 		.of_match_table = qup_i2c_dt_match,
2022 		.acpi_match_table = ACPI_PTR(qup_i2c_acpi_match),
2023 	},
2024 };
2025 
2026 module_platform_driver(qup_i2c_driver);
2027 
2028 MODULE_LICENSE("GPL v2");
2029 MODULE_ALIAS("platform:i2c_qup");
2030