xref: /openbmc/linux/drivers/i2c/busses/i2c-qup.c (revision 4d75f5c664195b970e1cd2fd25b65b5eff257a0a)
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 
458 		usleep_range(len, len * 2);
459 	}
460 
461 	return ret;
462 }
463 
qup_i2c_vote_bw(struct qup_i2c_dev * qup,u32 clk_freq)464 static int qup_i2c_vote_bw(struct qup_i2c_dev *qup, u32 clk_freq)
465 {
466 	u32 needed_peak_bw;
467 	int ret;
468 
469 	if (qup->cur_bw_clk_freq == clk_freq)
470 		return 0;
471 
472 	needed_peak_bw = Bps_to_icc(clk_freq * QUP_BUS_WIDTH);
473 	ret = icc_set_bw(qup->icc_path, 0, needed_peak_bw);
474 	if (ret)
475 		return ret;
476 
477 	qup->cur_bw_clk_freq = clk_freq;
478 	return 0;
479 }
480 
qup_i2c_write_tx_fifo_v1(struct qup_i2c_dev * qup)481 static void qup_i2c_write_tx_fifo_v1(struct qup_i2c_dev *qup)
482 {
483 	struct qup_i2c_block *blk = &qup->blk;
484 	struct i2c_msg *msg = qup->msg;
485 	u32 addr = i2c_8bit_addr_from_msg(msg);
486 	u32 qup_tag;
487 	int idx;
488 	u32 val;
489 
490 	if (qup->pos == 0) {
491 		val = QUP_TAG_START | addr;
492 		idx = 1;
493 		blk->tx_fifo_free--;
494 	} else {
495 		val = 0;
496 		idx = 0;
497 	}
498 
499 	while (blk->tx_fifo_free && qup->pos < msg->len) {
500 		if (qup->pos == msg->len - 1)
501 			qup_tag = QUP_TAG_STOP;
502 		else
503 			qup_tag = QUP_TAG_DATA;
504 
505 		if (idx & 1)
506 			val |= (qup_tag | msg->buf[qup->pos]) << QUP_MSW_SHIFT;
507 		else
508 			val = qup_tag | msg->buf[qup->pos];
509 
510 		/* Write out the pair and the last odd value */
511 		if (idx & 1 || qup->pos == msg->len - 1)
512 			writel(val, qup->base + QUP_OUT_FIFO_BASE);
513 
514 		qup->pos++;
515 		idx++;
516 		blk->tx_fifo_free--;
517 	}
518 }
519 
qup_i2c_set_blk_data(struct qup_i2c_dev * qup,struct i2c_msg * msg)520 static void qup_i2c_set_blk_data(struct qup_i2c_dev *qup,
521 				 struct i2c_msg *msg)
522 {
523 	qup->blk.pos = 0;
524 	qup->blk.data_len = msg->len;
525 	qup->blk.count = DIV_ROUND_UP(msg->len, qup->blk_xfer_limit);
526 }
527 
qup_i2c_get_data_len(struct qup_i2c_dev * qup)528 static int qup_i2c_get_data_len(struct qup_i2c_dev *qup)
529 {
530 	int data_len;
531 
532 	if (qup->blk.data_len > qup->blk_xfer_limit)
533 		data_len = qup->blk_xfer_limit;
534 	else
535 		data_len = qup->blk.data_len;
536 
537 	return data_len;
538 }
539 
qup_i2c_check_msg_len(struct i2c_msg * msg)540 static bool qup_i2c_check_msg_len(struct i2c_msg *msg)
541 {
542 	return ((msg->flags & I2C_M_RD) && (msg->flags & I2C_M_RECV_LEN));
543 }
544 
qup_i2c_set_tags_smb(u16 addr,u8 * tags,struct qup_i2c_dev * qup,struct i2c_msg * msg)545 static int qup_i2c_set_tags_smb(u16 addr, u8 *tags, struct qup_i2c_dev *qup,
546 			struct i2c_msg *msg)
547 {
548 	int len = 0;
549 
550 	if (qup->is_smbus_read) {
551 		tags[len++] = QUP_TAG_V2_DATARD_STOP;
552 		tags[len++] = qup_i2c_get_data_len(qup);
553 	} else {
554 		tags[len++] = QUP_TAG_V2_START;
555 		tags[len++] = addr & 0xff;
556 
557 		if (msg->flags & I2C_M_TEN)
558 			tags[len++] = addr >> 8;
559 
560 		tags[len++] = QUP_TAG_V2_DATARD;
561 		/* Read 1 byte indicating the length of the SMBus message */
562 		tags[len++] = 1;
563 	}
564 	return len;
565 }
566 
qup_i2c_set_tags(u8 * tags,struct qup_i2c_dev * qup,struct i2c_msg * msg)567 static int qup_i2c_set_tags(u8 *tags, struct qup_i2c_dev *qup,
568 			    struct i2c_msg *msg)
569 {
570 	u16 addr = i2c_8bit_addr_from_msg(msg);
571 	int len = 0;
572 	int data_len;
573 
574 	int last = (qup->blk.pos == (qup->blk.count - 1)) && (qup->is_last);
575 
576 	/* Handle tags for SMBus block read */
577 	if (qup_i2c_check_msg_len(msg))
578 		return qup_i2c_set_tags_smb(addr, tags, qup, msg);
579 
580 	if (qup->blk.pos == 0) {
581 		tags[len++] = QUP_TAG_V2_START;
582 		tags[len++] = addr & 0xff;
583 
584 		if (msg->flags & I2C_M_TEN)
585 			tags[len++] = addr >> 8;
586 	}
587 
588 	/* Send _STOP commands for the last block */
589 	if (last) {
590 		if (msg->flags & I2C_M_RD)
591 			tags[len++] = QUP_TAG_V2_DATARD_STOP;
592 		else
593 			tags[len++] = QUP_TAG_V2_DATAWR_STOP;
594 	} else {
595 		if (msg->flags & I2C_M_RD)
596 			tags[len++] = qup->blk.pos == (qup->blk.count - 1) ?
597 				      QUP_TAG_V2_DATARD_NACK :
598 				      QUP_TAG_V2_DATARD;
599 		else
600 			tags[len++] = QUP_TAG_V2_DATAWR;
601 	}
602 
603 	data_len = qup_i2c_get_data_len(qup);
604 
605 	/* 0 implies 256 bytes */
606 	if (data_len == QUP_READ_LIMIT)
607 		tags[len++] = 0;
608 	else
609 		tags[len++] = data_len;
610 
611 	return len;
612 }
613 
614 
qup_i2c_bam_cb(void * data)615 static void qup_i2c_bam_cb(void *data)
616 {
617 	struct qup_i2c_dev *qup = data;
618 
619 	complete(&qup->xfer);
620 }
621 
qup_sg_set_buf(struct scatterlist * sg,void * buf,unsigned int buflen,struct qup_i2c_dev * qup,int dir)622 static int qup_sg_set_buf(struct scatterlist *sg, void *buf,
623 			  unsigned int buflen, struct qup_i2c_dev *qup,
624 			  int dir)
625 {
626 	int ret;
627 
628 	sg_set_buf(sg, buf, buflen);
629 	ret = dma_map_sg(qup->dev, sg, 1, dir);
630 	if (!ret)
631 		return -EINVAL;
632 
633 	return 0;
634 }
635 
qup_i2c_rel_dma(struct qup_i2c_dev * qup)636 static void qup_i2c_rel_dma(struct qup_i2c_dev *qup)
637 {
638 	if (qup->btx.dma)
639 		dma_release_channel(qup->btx.dma);
640 	if (qup->brx.dma)
641 		dma_release_channel(qup->brx.dma);
642 	qup->btx.dma = NULL;
643 	qup->brx.dma = NULL;
644 }
645 
qup_i2c_req_dma(struct qup_i2c_dev * qup)646 static int qup_i2c_req_dma(struct qup_i2c_dev *qup)
647 {
648 	int err;
649 
650 	if (!qup->btx.dma) {
651 		qup->btx.dma = dma_request_chan(qup->dev, "tx");
652 		if (IS_ERR(qup->btx.dma)) {
653 			err = PTR_ERR(qup->btx.dma);
654 			qup->btx.dma = NULL;
655 			dev_err(qup->dev, "\n tx channel not available");
656 			return err;
657 		}
658 	}
659 
660 	if (!qup->brx.dma) {
661 		qup->brx.dma = dma_request_chan(qup->dev, "rx");
662 		if (IS_ERR(qup->brx.dma)) {
663 			dev_err(qup->dev, "\n rx channel not available");
664 			err = PTR_ERR(qup->brx.dma);
665 			qup->brx.dma = NULL;
666 			qup_i2c_rel_dma(qup);
667 			return err;
668 		}
669 	}
670 	return 0;
671 }
672 
qup_i2c_bam_make_desc(struct qup_i2c_dev * qup,struct i2c_msg * msg)673 static int qup_i2c_bam_make_desc(struct qup_i2c_dev *qup, struct i2c_msg *msg)
674 {
675 	int ret = 0, limit = QUP_READ_LIMIT;
676 	u32 len = 0, blocks, rem;
677 	u32 i = 0, tlen, tx_len = 0;
678 	u8 *tags;
679 
680 	qup->blk_xfer_limit = QUP_READ_LIMIT;
681 	qup_i2c_set_blk_data(qup, msg);
682 
683 	blocks = qup->blk.count;
684 	rem = msg->len - (blocks - 1) * limit;
685 
686 	if (msg->flags & I2C_M_RD) {
687 		while (qup->blk.pos < blocks) {
688 			tlen = (i == (blocks - 1)) ? rem : limit;
689 			tags = &qup->start_tag.start[qup->tag_buf_pos + len];
690 			len += qup_i2c_set_tags(tags, qup, msg);
691 			qup->blk.data_len -= tlen;
692 
693 			/* scratch buf to read the start and len tags */
694 			ret = qup_sg_set_buf(&qup->brx.sg[qup->brx.sg_cnt++],
695 					     &qup->brx.tag.start[0],
696 					     2, qup, DMA_FROM_DEVICE);
697 
698 			if (ret)
699 				return ret;
700 
701 			ret = qup_sg_set_buf(&qup->brx.sg[qup->brx.sg_cnt++],
702 					     &msg->buf[limit * i],
703 					     tlen, qup,
704 					     DMA_FROM_DEVICE);
705 			if (ret)
706 				return ret;
707 
708 			i++;
709 			qup->blk.pos = i;
710 		}
711 		ret = qup_sg_set_buf(&qup->btx.sg[qup->btx.sg_cnt++],
712 				     &qup->start_tag.start[qup->tag_buf_pos],
713 				     len, qup, DMA_TO_DEVICE);
714 		if (ret)
715 			return ret;
716 
717 		qup->tag_buf_pos += len;
718 	} else {
719 		while (qup->blk.pos < blocks) {
720 			tlen = (i == (blocks - 1)) ? rem : limit;
721 			tags = &qup->start_tag.start[qup->tag_buf_pos + tx_len];
722 			len = qup_i2c_set_tags(tags, qup, msg);
723 			qup->blk.data_len -= tlen;
724 
725 			ret = qup_sg_set_buf(&qup->btx.sg[qup->btx.sg_cnt++],
726 					     tags, len,
727 					     qup, DMA_TO_DEVICE);
728 			if (ret)
729 				return ret;
730 
731 			tx_len += len;
732 			ret = qup_sg_set_buf(&qup->btx.sg[qup->btx.sg_cnt++],
733 					     &msg->buf[limit * i],
734 					     tlen, qup, DMA_TO_DEVICE);
735 			if (ret)
736 				return ret;
737 			i++;
738 			qup->blk.pos = i;
739 		}
740 
741 		qup->tag_buf_pos += tx_len;
742 	}
743 
744 	return 0;
745 }
746 
qup_i2c_bam_schedule_desc(struct qup_i2c_dev * qup)747 static int qup_i2c_bam_schedule_desc(struct qup_i2c_dev *qup)
748 {
749 	struct dma_async_tx_descriptor *txd, *rxd = NULL;
750 	int ret = 0;
751 	dma_cookie_t cookie_rx, cookie_tx;
752 	u32 len = 0;
753 	u32 tx_cnt = qup->btx.sg_cnt, rx_cnt = qup->brx.sg_cnt;
754 
755 	/* schedule the EOT and FLUSH I2C tags */
756 	len = 1;
757 	if (rx_cnt) {
758 		qup->btx.tag.start[0] = QUP_BAM_INPUT_EOT;
759 		len++;
760 
761 		/* scratch buf to read the BAM EOT FLUSH tags */
762 		ret = qup_sg_set_buf(&qup->brx.sg[rx_cnt++],
763 				     &qup->brx.tag.start[0],
764 				     1, qup, DMA_FROM_DEVICE);
765 		if (ret)
766 			return ret;
767 	}
768 
769 	qup->btx.tag.start[len - 1] = QUP_BAM_FLUSH_STOP;
770 	ret = qup_sg_set_buf(&qup->btx.sg[tx_cnt++], &qup->btx.tag.start[0],
771 			     len, qup, DMA_TO_DEVICE);
772 	if (ret)
773 		return ret;
774 
775 	txd = dmaengine_prep_slave_sg(qup->btx.dma, qup->btx.sg, tx_cnt,
776 				      DMA_MEM_TO_DEV,
777 				      DMA_PREP_INTERRUPT | DMA_PREP_FENCE);
778 	if (!txd) {
779 		dev_err(qup->dev, "failed to get tx desc\n");
780 		ret = -EINVAL;
781 		goto desc_err;
782 	}
783 
784 	if (!rx_cnt) {
785 		txd->callback = qup_i2c_bam_cb;
786 		txd->callback_param = qup;
787 	}
788 
789 	cookie_tx = dmaengine_submit(txd);
790 	if (dma_submit_error(cookie_tx)) {
791 		ret = -EINVAL;
792 		goto desc_err;
793 	}
794 
795 	dma_async_issue_pending(qup->btx.dma);
796 
797 	if (rx_cnt) {
798 		rxd = dmaengine_prep_slave_sg(qup->brx.dma, qup->brx.sg,
799 					      rx_cnt, DMA_DEV_TO_MEM,
800 					      DMA_PREP_INTERRUPT);
801 		if (!rxd) {
802 			dev_err(qup->dev, "failed to get rx desc\n");
803 			ret = -EINVAL;
804 
805 			/* abort TX descriptors */
806 			dmaengine_terminate_sync(qup->btx.dma);
807 			goto desc_err;
808 		}
809 
810 		rxd->callback = qup_i2c_bam_cb;
811 		rxd->callback_param = qup;
812 		cookie_rx = dmaengine_submit(rxd);
813 		if (dma_submit_error(cookie_rx)) {
814 			ret = -EINVAL;
815 			goto desc_err;
816 		}
817 
818 		dma_async_issue_pending(qup->brx.dma);
819 	}
820 
821 	if (!wait_for_completion_timeout(&qup->xfer, qup->xfer_timeout)) {
822 		dev_err(qup->dev, "normal trans timed out\n");
823 		ret = -ETIMEDOUT;
824 	}
825 
826 	if (ret || qup->bus_err || qup->qup_err) {
827 		reinit_completion(&qup->xfer);
828 
829 		ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
830 		if (ret) {
831 			dev_err(qup->dev, "change to run state timed out");
832 			goto desc_err;
833 		}
834 
835 		qup_i2c_flush(qup);
836 
837 		/* wait for remaining interrupts to occur */
838 		if (!wait_for_completion_timeout(&qup->xfer, HZ))
839 			dev_err(qup->dev, "flush timed out\n");
840 
841 		ret =  (qup->bus_err & QUP_I2C_NACK_FLAG) ? -ENXIO : -EIO;
842 	}
843 
844 desc_err:
845 	dma_unmap_sg(qup->dev, qup->btx.sg, tx_cnt, DMA_TO_DEVICE);
846 
847 	if (rx_cnt)
848 		dma_unmap_sg(qup->dev, qup->brx.sg, rx_cnt,
849 			     DMA_FROM_DEVICE);
850 
851 	return ret;
852 }
853 
qup_i2c_bam_clear_tag_buffers(struct qup_i2c_dev * qup)854 static void qup_i2c_bam_clear_tag_buffers(struct qup_i2c_dev *qup)
855 {
856 	qup->btx.sg_cnt = 0;
857 	qup->brx.sg_cnt = 0;
858 	qup->tag_buf_pos = 0;
859 }
860 
qup_i2c_bam_xfer(struct i2c_adapter * adap,struct i2c_msg * msg,int num)861 static int qup_i2c_bam_xfer(struct i2c_adapter *adap, struct i2c_msg *msg,
862 			    int num)
863 {
864 	struct qup_i2c_dev *qup = i2c_get_adapdata(adap);
865 	int ret = 0;
866 	int idx = 0;
867 
868 	ret = qup_i2c_vote_bw(qup, qup->src_clk_freq);
869 	if (ret)
870 		return ret;
871 
872 	enable_irq(qup->irq);
873 	ret = qup_i2c_req_dma(qup);
874 
875 	if (ret)
876 		goto out;
877 
878 	writel(0, qup->base + QUP_MX_INPUT_CNT);
879 	writel(0, qup->base + QUP_MX_OUTPUT_CNT);
880 
881 	/* set BAM mode */
882 	writel(QUP_REPACK_EN | QUP_BAM_MODE, qup->base + QUP_IO_MODE);
883 
884 	/* mask fifo irqs */
885 	writel((0x3 << 8), qup->base + QUP_OPERATIONAL_MASK);
886 
887 	/* set RUN STATE */
888 	ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
889 	if (ret)
890 		goto out;
891 
892 	writel(qup->clk_ctl, qup->base + QUP_I2C_CLK_CTL);
893 	qup_i2c_bam_clear_tag_buffers(qup);
894 
895 	for (idx = 0; idx < num; idx++) {
896 		qup->msg = msg + idx;
897 		qup->is_last = idx == (num - 1);
898 
899 		ret = qup_i2c_bam_make_desc(qup, qup->msg);
900 		if (ret)
901 			break;
902 
903 		/*
904 		 * Make DMA descriptor and schedule the BAM transfer if its
905 		 * already crossed the maximum length. Since the memory for all
906 		 * tags buffers have been taken for 2 maximum possible
907 		 * transfers length so it will never cross the buffer actual
908 		 * length.
909 		 */
910 		if (qup->btx.sg_cnt > qup->max_xfer_sg_len ||
911 		    qup->brx.sg_cnt > qup->max_xfer_sg_len ||
912 		    qup->is_last) {
913 			ret = qup_i2c_bam_schedule_desc(qup);
914 			if (ret)
915 				break;
916 
917 			qup_i2c_bam_clear_tag_buffers(qup);
918 		}
919 	}
920 
921 out:
922 	disable_irq(qup->irq);
923 
924 	qup->msg = NULL;
925 	return ret;
926 }
927 
qup_i2c_wait_for_complete(struct qup_i2c_dev * qup,struct i2c_msg * msg)928 static int qup_i2c_wait_for_complete(struct qup_i2c_dev *qup,
929 				     struct i2c_msg *msg)
930 {
931 	unsigned long left;
932 	int ret = 0;
933 
934 	left = wait_for_completion_timeout(&qup->xfer, qup->xfer_timeout);
935 	if (!left) {
936 		writel(1, qup->base + QUP_SW_RESET);
937 		ret = -ETIMEDOUT;
938 	}
939 
940 	if (qup->bus_err || qup->qup_err)
941 		ret =  (qup->bus_err & QUP_I2C_NACK_FLAG) ? -ENXIO : -EIO;
942 
943 	return ret;
944 }
945 
qup_i2c_read_rx_fifo_v1(struct qup_i2c_dev * qup)946 static void qup_i2c_read_rx_fifo_v1(struct qup_i2c_dev *qup)
947 {
948 	struct qup_i2c_block *blk = &qup->blk;
949 	struct i2c_msg *msg = qup->msg;
950 	u32 val = 0;
951 	int idx = 0;
952 
953 	while (blk->fifo_available && qup->pos < msg->len) {
954 		if ((idx & 1) == 0) {
955 			/* Reading 2 words at time */
956 			val = readl(qup->base + QUP_IN_FIFO_BASE);
957 			msg->buf[qup->pos++] = val & 0xFF;
958 		} else {
959 			msg->buf[qup->pos++] = val >> QUP_MSW_SHIFT;
960 		}
961 		idx++;
962 		blk->fifo_available--;
963 	}
964 
965 	if (qup->pos == msg->len)
966 		blk->rx_bytes_read = true;
967 }
968 
qup_i2c_write_rx_tags_v1(struct qup_i2c_dev * qup)969 static void qup_i2c_write_rx_tags_v1(struct qup_i2c_dev *qup)
970 {
971 	struct i2c_msg *msg = qup->msg;
972 	u32 addr, len, val;
973 
974 	addr = i2c_8bit_addr_from_msg(msg);
975 
976 	/* 0 is used to specify a length 256 (QUP_READ_LIMIT) */
977 	len = (msg->len == QUP_READ_LIMIT) ? 0 : msg->len;
978 
979 	val = ((QUP_TAG_REC | len) << QUP_MSW_SHIFT) | QUP_TAG_START | addr;
980 	writel(val, qup->base + QUP_OUT_FIFO_BASE);
981 }
982 
qup_i2c_conf_v1(struct qup_i2c_dev * qup)983 static void qup_i2c_conf_v1(struct qup_i2c_dev *qup)
984 {
985 	struct qup_i2c_block *blk = &qup->blk;
986 	u32 qup_config = I2C_MINI_CORE | I2C_N_VAL;
987 	u32 io_mode = QUP_REPACK_EN;
988 
989 	blk->is_tx_blk_mode = blk->total_tx_len > qup->out_fifo_sz;
990 	blk->is_rx_blk_mode = blk->total_rx_len > qup->in_fifo_sz;
991 
992 	if (blk->is_tx_blk_mode) {
993 		io_mode |= QUP_OUTPUT_BLK_MODE;
994 		writel(0, qup->base + QUP_MX_WRITE_CNT);
995 		writel(blk->total_tx_len, qup->base + QUP_MX_OUTPUT_CNT);
996 	} else {
997 		writel(0, qup->base + QUP_MX_OUTPUT_CNT);
998 		writel(blk->total_tx_len, qup->base + QUP_MX_WRITE_CNT);
999 	}
1000 
1001 	if (blk->total_rx_len) {
1002 		if (blk->is_rx_blk_mode) {
1003 			io_mode |= QUP_INPUT_BLK_MODE;
1004 			writel(0, qup->base + QUP_MX_READ_CNT);
1005 			writel(blk->total_rx_len, qup->base + QUP_MX_INPUT_CNT);
1006 		} else {
1007 			writel(0, qup->base + QUP_MX_INPUT_CNT);
1008 			writel(blk->total_rx_len, qup->base + QUP_MX_READ_CNT);
1009 		}
1010 	} else {
1011 		qup_config |= QUP_NO_INPUT;
1012 	}
1013 
1014 	writel(qup_config, qup->base + QUP_CONFIG);
1015 	writel(io_mode, qup->base + QUP_IO_MODE);
1016 }
1017 
qup_i2c_clear_blk_v1(struct qup_i2c_block * blk)1018 static void qup_i2c_clear_blk_v1(struct qup_i2c_block *blk)
1019 {
1020 	blk->tx_fifo_free = 0;
1021 	blk->fifo_available = 0;
1022 	blk->rx_bytes_read = false;
1023 }
1024 
qup_i2c_conf_xfer_v1(struct qup_i2c_dev * qup,bool is_rx)1025 static int qup_i2c_conf_xfer_v1(struct qup_i2c_dev *qup, bool is_rx)
1026 {
1027 	struct qup_i2c_block *blk = &qup->blk;
1028 	int ret;
1029 
1030 	qup_i2c_clear_blk_v1(blk);
1031 	qup_i2c_conf_v1(qup);
1032 	ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
1033 	if (ret)
1034 		return ret;
1035 
1036 	writel(qup->clk_ctl, qup->base + QUP_I2C_CLK_CTL);
1037 
1038 	ret = qup_i2c_change_state(qup, QUP_PAUSE_STATE);
1039 	if (ret)
1040 		return ret;
1041 
1042 	reinit_completion(&qup->xfer);
1043 	enable_irq(qup->irq);
1044 	if (!blk->is_tx_blk_mode) {
1045 		blk->tx_fifo_free = qup->out_fifo_sz;
1046 
1047 		if (is_rx)
1048 			qup_i2c_write_rx_tags_v1(qup);
1049 		else
1050 			qup_i2c_write_tx_fifo_v1(qup);
1051 	}
1052 
1053 	ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
1054 	if (ret)
1055 		goto err;
1056 
1057 	ret = qup_i2c_wait_for_complete(qup, qup->msg);
1058 	if (ret)
1059 		goto err;
1060 
1061 	ret = qup_i2c_bus_active(qup, ONE_BYTE);
1062 
1063 err:
1064 	disable_irq(qup->irq);
1065 	return ret;
1066 }
1067 
qup_i2c_write_one(struct qup_i2c_dev * qup)1068 static int qup_i2c_write_one(struct qup_i2c_dev *qup)
1069 {
1070 	struct i2c_msg *msg = qup->msg;
1071 	struct qup_i2c_block *blk = &qup->blk;
1072 
1073 	qup->pos = 0;
1074 	blk->total_tx_len = msg->len + 1;
1075 	blk->total_rx_len = 0;
1076 
1077 	return qup_i2c_conf_xfer_v1(qup, false);
1078 }
1079 
qup_i2c_read_one(struct qup_i2c_dev * qup)1080 static int qup_i2c_read_one(struct qup_i2c_dev *qup)
1081 {
1082 	struct qup_i2c_block *blk = &qup->blk;
1083 
1084 	qup->pos = 0;
1085 	blk->total_tx_len = 2;
1086 	blk->total_rx_len = qup->msg->len;
1087 
1088 	return qup_i2c_conf_xfer_v1(qup, true);
1089 }
1090 
qup_i2c_xfer(struct i2c_adapter * adap,struct i2c_msg msgs[],int num)1091 static int qup_i2c_xfer(struct i2c_adapter *adap,
1092 			struct i2c_msg msgs[],
1093 			int num)
1094 {
1095 	struct qup_i2c_dev *qup = i2c_get_adapdata(adap);
1096 	int ret, idx;
1097 
1098 	ret = pm_runtime_get_sync(qup->dev);
1099 	if (ret < 0)
1100 		goto out;
1101 
1102 	qup->bus_err = 0;
1103 	qup->qup_err = 0;
1104 
1105 	writel(1, qup->base + QUP_SW_RESET);
1106 	ret = qup_i2c_poll_state(qup, QUP_RESET_STATE);
1107 	if (ret)
1108 		goto out;
1109 
1110 	/* Configure QUP as I2C mini core */
1111 	writel(I2C_MINI_CORE | I2C_N_VAL, qup->base + QUP_CONFIG);
1112 
1113 	for (idx = 0; idx < num; idx++) {
1114 		if (qup_i2c_poll_state_i2c_master(qup)) {
1115 			ret = -EIO;
1116 			goto out;
1117 		}
1118 
1119 		if (qup_i2c_check_msg_len(&msgs[idx])) {
1120 			ret = -EINVAL;
1121 			goto out;
1122 		}
1123 
1124 		qup->msg = &msgs[idx];
1125 		if (msgs[idx].flags & I2C_M_RD)
1126 			ret = qup_i2c_read_one(qup);
1127 		else
1128 			ret = qup_i2c_write_one(qup);
1129 
1130 		if (ret)
1131 			break;
1132 
1133 		ret = qup_i2c_change_state(qup, QUP_RESET_STATE);
1134 		if (ret)
1135 			break;
1136 	}
1137 
1138 	if (ret == 0)
1139 		ret = num;
1140 out:
1141 
1142 	pm_runtime_mark_last_busy(qup->dev);
1143 	pm_runtime_put_autosuspend(qup->dev);
1144 
1145 	return ret;
1146 }
1147 
1148 /*
1149  * Configure registers related with reconfiguration during run and call it
1150  * before each i2c sub transfer.
1151  */
qup_i2c_conf_count_v2(struct qup_i2c_dev * qup)1152 static void qup_i2c_conf_count_v2(struct qup_i2c_dev *qup)
1153 {
1154 	struct qup_i2c_block *blk = &qup->blk;
1155 	u32 qup_config = I2C_MINI_CORE | I2C_N_VAL_V2;
1156 
1157 	if (blk->is_tx_blk_mode)
1158 		writel(qup->config_run | blk->total_tx_len,
1159 		       qup->base + QUP_MX_OUTPUT_CNT);
1160 	else
1161 		writel(qup->config_run | blk->total_tx_len,
1162 		       qup->base + QUP_MX_WRITE_CNT);
1163 
1164 	if (blk->total_rx_len) {
1165 		if (blk->is_rx_blk_mode)
1166 			writel(qup->config_run | blk->total_rx_len,
1167 			       qup->base + QUP_MX_INPUT_CNT);
1168 		else
1169 			writel(qup->config_run | blk->total_rx_len,
1170 			       qup->base + QUP_MX_READ_CNT);
1171 	} else {
1172 		qup_config |= QUP_NO_INPUT;
1173 	}
1174 
1175 	writel(qup_config, qup->base + QUP_CONFIG);
1176 }
1177 
1178 /*
1179  * Configure registers related with transfer mode (FIFO/Block)
1180  * before starting of i2c transfer. It will be called only once in
1181  * QUP RESET state.
1182  */
qup_i2c_conf_mode_v2(struct qup_i2c_dev * qup)1183 static void qup_i2c_conf_mode_v2(struct qup_i2c_dev *qup)
1184 {
1185 	struct qup_i2c_block *blk = &qup->blk;
1186 	u32 io_mode = QUP_REPACK_EN;
1187 
1188 	if (blk->is_tx_blk_mode) {
1189 		io_mode |= QUP_OUTPUT_BLK_MODE;
1190 		writel(0, qup->base + QUP_MX_WRITE_CNT);
1191 	} else {
1192 		writel(0, qup->base + QUP_MX_OUTPUT_CNT);
1193 	}
1194 
1195 	if (blk->is_rx_blk_mode) {
1196 		io_mode |= QUP_INPUT_BLK_MODE;
1197 		writel(0, qup->base + QUP_MX_READ_CNT);
1198 	} else {
1199 		writel(0, qup->base + QUP_MX_INPUT_CNT);
1200 	}
1201 
1202 	writel(io_mode, qup->base + QUP_IO_MODE);
1203 }
1204 
1205 /* Clear required variables before starting of any QUP v2 sub transfer. */
qup_i2c_clear_blk_v2(struct qup_i2c_block * blk)1206 static void qup_i2c_clear_blk_v2(struct qup_i2c_block *blk)
1207 {
1208 	blk->send_last_word = false;
1209 	blk->tx_tags_sent = false;
1210 	blk->tx_fifo_data = 0;
1211 	blk->tx_fifo_data_pos = 0;
1212 	blk->tx_fifo_free = 0;
1213 
1214 	blk->rx_tags_fetched = false;
1215 	blk->rx_bytes_read = false;
1216 	blk->rx_fifo_data = 0;
1217 	blk->rx_fifo_data_pos = 0;
1218 	blk->fifo_available = 0;
1219 }
1220 
1221 /* Receive data from RX FIFO for read message in QUP v2 i2c transfer. */
qup_i2c_recv_data(struct qup_i2c_dev * qup)1222 static void qup_i2c_recv_data(struct qup_i2c_dev *qup)
1223 {
1224 	struct qup_i2c_block *blk = &qup->blk;
1225 	int j;
1226 
1227 	for (j = blk->rx_fifo_data_pos;
1228 	     blk->cur_blk_len && blk->fifo_available;
1229 	     blk->cur_blk_len--, blk->fifo_available--) {
1230 		if (j == 0)
1231 			blk->rx_fifo_data = readl(qup->base + QUP_IN_FIFO_BASE);
1232 
1233 		*(blk->cur_data++) = blk->rx_fifo_data;
1234 		blk->rx_fifo_data >>= 8;
1235 
1236 		if (j == 3)
1237 			j = 0;
1238 		else
1239 			j++;
1240 	}
1241 
1242 	blk->rx_fifo_data_pos = j;
1243 }
1244 
1245 /* Receive tags for read message in QUP v2 i2c transfer. */
qup_i2c_recv_tags(struct qup_i2c_dev * qup)1246 static void qup_i2c_recv_tags(struct qup_i2c_dev *qup)
1247 {
1248 	struct qup_i2c_block *blk = &qup->blk;
1249 
1250 	blk->rx_fifo_data = readl(qup->base + QUP_IN_FIFO_BASE);
1251 	blk->rx_fifo_data >>= blk->rx_tag_len  * 8;
1252 	blk->rx_fifo_data_pos = blk->rx_tag_len;
1253 	blk->fifo_available -= blk->rx_tag_len;
1254 }
1255 
1256 /*
1257  * Read the data and tags from RX FIFO. Since in read case, the tags will be
1258  * preceded by received data bytes so
1259  * 1. Check if rx_tags_fetched is false i.e. the start of QUP block so receive
1260  *    all tag bytes and discard that.
1261  * 2. Read the data from RX FIFO. When all the data bytes have been read then
1262  *    set rx_bytes_read to true.
1263  */
qup_i2c_read_rx_fifo_v2(struct qup_i2c_dev * qup)1264 static void qup_i2c_read_rx_fifo_v2(struct qup_i2c_dev *qup)
1265 {
1266 	struct qup_i2c_block *blk = &qup->blk;
1267 
1268 	if (!blk->rx_tags_fetched) {
1269 		qup_i2c_recv_tags(qup);
1270 		blk->rx_tags_fetched = true;
1271 	}
1272 
1273 	qup_i2c_recv_data(qup);
1274 	if (!blk->cur_blk_len)
1275 		blk->rx_bytes_read = true;
1276 }
1277 
1278 /*
1279  * Write bytes in TX FIFO for write message in QUP v2 i2c transfer. QUP TX FIFO
1280  * write works on word basis (4 bytes). Append new data byte write for TX FIFO
1281  * in tx_fifo_data and write to TX FIFO when all the 4 bytes are present.
1282  */
1283 static void
qup_i2c_write_blk_data(struct qup_i2c_dev * qup,u8 ** data,unsigned int * len)1284 qup_i2c_write_blk_data(struct qup_i2c_dev *qup, u8 **data, unsigned int *len)
1285 {
1286 	struct qup_i2c_block *blk = &qup->blk;
1287 	unsigned int j;
1288 
1289 	for (j = blk->tx_fifo_data_pos; *len && blk->tx_fifo_free;
1290 	     (*len)--, blk->tx_fifo_free--) {
1291 		blk->tx_fifo_data |= *(*data)++ << (j * 8);
1292 		if (j == 3) {
1293 			writel(blk->tx_fifo_data,
1294 			       qup->base + QUP_OUT_FIFO_BASE);
1295 			blk->tx_fifo_data = 0x0;
1296 			j = 0;
1297 		} else {
1298 			j++;
1299 		}
1300 	}
1301 
1302 	blk->tx_fifo_data_pos = j;
1303 }
1304 
1305 /* Transfer tags for read message in QUP v2 i2c transfer. */
qup_i2c_write_rx_tags_v2(struct qup_i2c_dev * qup)1306 static void qup_i2c_write_rx_tags_v2(struct qup_i2c_dev *qup)
1307 {
1308 	struct qup_i2c_block *blk = &qup->blk;
1309 
1310 	qup_i2c_write_blk_data(qup, &blk->cur_tx_tags, &blk->tx_tag_len);
1311 	if (blk->tx_fifo_data_pos)
1312 		writel(blk->tx_fifo_data, qup->base + QUP_OUT_FIFO_BASE);
1313 }
1314 
1315 /*
1316  * Write the data and tags in TX FIFO. Since in write case, both tags and data
1317  * need to be written and QUP write tags can have maximum 256 data length, so
1318  *
1319  * 1. Check if tx_tags_sent is false i.e. the start of QUP block so write the
1320  *    tags to TX FIFO and set tx_tags_sent to true.
1321  * 2. Check if send_last_word is true. It will be set when last few data bytes
1322  *    (less than 4 bytes) are remaining to be written in FIFO because of no FIFO
1323  *    space. All this data bytes are available in tx_fifo_data so write this
1324  *    in FIFO.
1325  * 3. Write the data to TX FIFO and check for cur_blk_len. If it is non zero
1326  *    then more data is pending otherwise following 3 cases can be possible
1327  *    a. if tx_fifo_data_pos is zero i.e. all the data bytes in this block
1328  *       have been written in TX FIFO so nothing else is required.
1329  *    b. tx_fifo_free is non zero i.e tx FIFO is free so copy the remaining data
1330  *       from tx_fifo_data to tx FIFO. Since, qup_i2c_write_blk_data do write
1331  *	 in 4 bytes and FIFO space is in multiple of 4 bytes so tx_fifo_free
1332  *       will be always greater than or equal to 4 bytes.
1333  *    c. tx_fifo_free is zero. In this case, last few bytes (less than 4
1334  *       bytes) are copied to tx_fifo_data but couldn't be sent because of
1335  *       FIFO full so make send_last_word true.
1336  */
qup_i2c_write_tx_fifo_v2(struct qup_i2c_dev * qup)1337 static void qup_i2c_write_tx_fifo_v2(struct qup_i2c_dev *qup)
1338 {
1339 	struct qup_i2c_block *blk = &qup->blk;
1340 
1341 	if (!blk->tx_tags_sent) {
1342 		qup_i2c_write_blk_data(qup, &blk->cur_tx_tags,
1343 				       &blk->tx_tag_len);
1344 		blk->tx_tags_sent = true;
1345 	}
1346 
1347 	if (blk->send_last_word)
1348 		goto send_last_word;
1349 
1350 	qup_i2c_write_blk_data(qup, &blk->cur_data, &blk->cur_blk_len);
1351 	if (!blk->cur_blk_len) {
1352 		if (!blk->tx_fifo_data_pos)
1353 			return;
1354 
1355 		if (blk->tx_fifo_free)
1356 			goto send_last_word;
1357 
1358 		blk->send_last_word = true;
1359 	}
1360 
1361 	return;
1362 
1363 send_last_word:
1364 	writel(blk->tx_fifo_data, qup->base + QUP_OUT_FIFO_BASE);
1365 }
1366 
1367 /*
1368  * Main transfer function which read or write i2c data.
1369  * The QUP v2 supports reconfiguration during run in which multiple i2c sub
1370  * transfers can be scheduled.
1371  */
1372 static int
qup_i2c_conf_xfer_v2(struct qup_i2c_dev * qup,bool is_rx,bool is_first,bool change_pause_state)1373 qup_i2c_conf_xfer_v2(struct qup_i2c_dev *qup, bool is_rx, bool is_first,
1374 		     bool change_pause_state)
1375 {
1376 	struct qup_i2c_block *blk = &qup->blk;
1377 	struct i2c_msg *msg = qup->msg;
1378 	int ret;
1379 
1380 	/*
1381 	 * Check if its SMBus Block read for which the top level read will be
1382 	 * done into 2 QUP reads. One with message length 1 while other one is
1383 	 * with actual length.
1384 	 */
1385 	if (qup_i2c_check_msg_len(msg)) {
1386 		if (qup->is_smbus_read) {
1387 			/*
1388 			 * If the message length is already read in
1389 			 * the first byte of the buffer, account for
1390 			 * that by setting the offset
1391 			 */
1392 			blk->cur_data += 1;
1393 			is_first = false;
1394 		} else {
1395 			change_pause_state = false;
1396 		}
1397 	}
1398 
1399 	qup->config_run = is_first ? 0 : QUP_I2C_MX_CONFIG_DURING_RUN;
1400 
1401 	qup_i2c_clear_blk_v2(blk);
1402 	qup_i2c_conf_count_v2(qup);
1403 
1404 	/* If it is first sub transfer, then configure i2c bus clocks */
1405 	if (is_first) {
1406 		ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
1407 		if (ret)
1408 			return ret;
1409 
1410 		writel(qup->clk_ctl, qup->base + QUP_I2C_CLK_CTL);
1411 
1412 		ret = qup_i2c_change_state(qup, QUP_PAUSE_STATE);
1413 		if (ret)
1414 			return ret;
1415 	}
1416 
1417 	reinit_completion(&qup->xfer);
1418 	enable_irq(qup->irq);
1419 	/*
1420 	 * In FIFO mode, tx FIFO can be written directly while in block mode the
1421 	 * it will be written after getting OUT_BLOCK_WRITE_REQ interrupt
1422 	 */
1423 	if (!blk->is_tx_blk_mode) {
1424 		blk->tx_fifo_free = qup->out_fifo_sz;
1425 
1426 		if (is_rx)
1427 			qup_i2c_write_rx_tags_v2(qup);
1428 		else
1429 			qup_i2c_write_tx_fifo_v2(qup);
1430 	}
1431 
1432 	ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
1433 	if (ret)
1434 		goto err;
1435 
1436 	ret = qup_i2c_wait_for_complete(qup, msg);
1437 	if (ret)
1438 		goto err;
1439 
1440 	/* Move to pause state for all the transfers, except last one */
1441 	if (change_pause_state) {
1442 		ret = qup_i2c_change_state(qup, QUP_PAUSE_STATE);
1443 		if (ret)
1444 			goto err;
1445 	}
1446 
1447 err:
1448 	disable_irq(qup->irq);
1449 	return ret;
1450 }
1451 
1452 /*
1453  * Transfer one read/write message in i2c transfer. It splits the message into
1454  * multiple of blk_xfer_limit data length blocks and schedule each
1455  * QUP block individually.
1456  */
qup_i2c_xfer_v2_msg(struct qup_i2c_dev * qup,int msg_id,bool is_rx)1457 static int qup_i2c_xfer_v2_msg(struct qup_i2c_dev *qup, int msg_id, bool is_rx)
1458 {
1459 	int ret = 0;
1460 	unsigned int data_len, i;
1461 	struct i2c_msg *msg = qup->msg;
1462 	struct qup_i2c_block *blk = &qup->blk;
1463 	u8 *msg_buf = msg->buf;
1464 
1465 	qup->blk_xfer_limit = is_rx ? RECV_MAX_DATA_LEN : QUP_READ_LIMIT;
1466 	qup_i2c_set_blk_data(qup, msg);
1467 
1468 	for (i = 0; i < blk->count; i++) {
1469 		data_len =  qup_i2c_get_data_len(qup);
1470 		blk->pos = i;
1471 		blk->cur_tx_tags = blk->tags;
1472 		blk->cur_blk_len = data_len;
1473 		blk->tx_tag_len =
1474 			qup_i2c_set_tags(blk->cur_tx_tags, qup, qup->msg);
1475 
1476 		blk->cur_data = msg_buf;
1477 
1478 		if (is_rx) {
1479 			blk->total_tx_len = blk->tx_tag_len;
1480 			blk->rx_tag_len = 2;
1481 			blk->total_rx_len = blk->rx_tag_len + data_len;
1482 		} else {
1483 			blk->total_tx_len = blk->tx_tag_len + data_len;
1484 			blk->total_rx_len = 0;
1485 		}
1486 
1487 		ret = qup_i2c_conf_xfer_v2(qup, is_rx, !msg_id && !i,
1488 					   !qup->is_last || i < blk->count - 1);
1489 		if (ret)
1490 			return ret;
1491 
1492 		/* Handle SMBus block read length */
1493 		if (qup_i2c_check_msg_len(msg) && msg->len == 1 &&
1494 		    !qup->is_smbus_read) {
1495 			if (msg->buf[0] > I2C_SMBUS_BLOCK_MAX)
1496 				return -EPROTO;
1497 
1498 			msg->len = msg->buf[0];
1499 			qup->is_smbus_read = true;
1500 			ret = qup_i2c_xfer_v2_msg(qup, msg_id, true);
1501 			qup->is_smbus_read = false;
1502 			if (ret)
1503 				return ret;
1504 
1505 			msg->len += 1;
1506 		}
1507 
1508 		msg_buf += data_len;
1509 		blk->data_len -= qup->blk_xfer_limit;
1510 	}
1511 
1512 	return ret;
1513 }
1514 
1515 /*
1516  * QUP v2 supports 3 modes
1517  * Programmed IO using FIFO mode : Less than FIFO size
1518  * Programmed IO using Block mode : Greater than FIFO size
1519  * DMA using BAM : Appropriate for any transaction size but the address should
1520  *		   be DMA applicable
1521  *
1522  * This function determines the mode which will be used for this transfer. An
1523  * i2c transfer contains multiple message. Following are the rules to determine
1524  * the mode used.
1525  * 1. Determine complete length, maximum tx and rx length for complete transfer.
1526  * 2. If complete transfer length is greater than fifo size then use the DMA
1527  *    mode.
1528  * 3. In FIFO or block mode, tx and rx can operate in different mode so check
1529  *    for maximum tx and rx length to determine mode.
1530  */
1531 static int
qup_i2c_determine_mode_v2(struct qup_i2c_dev * qup,struct i2c_msg msgs[],int num)1532 qup_i2c_determine_mode_v2(struct qup_i2c_dev *qup,
1533 			  struct i2c_msg msgs[], int num)
1534 {
1535 	int idx;
1536 	bool no_dma = false;
1537 	unsigned int max_tx_len = 0, max_rx_len = 0, total_len = 0;
1538 
1539 	/* All i2c_msgs should be transferred using either dma or cpu */
1540 	for (idx = 0; idx < num; idx++) {
1541 		if (msgs[idx].flags & I2C_M_RD)
1542 			max_rx_len = max_t(unsigned int, max_rx_len,
1543 					   msgs[idx].len);
1544 		else
1545 			max_tx_len = max_t(unsigned int, max_tx_len,
1546 					   msgs[idx].len);
1547 
1548 		if (is_vmalloc_addr(msgs[idx].buf))
1549 			no_dma = true;
1550 
1551 		total_len += msgs[idx].len;
1552 	}
1553 
1554 	if (!no_dma && qup->is_dma &&
1555 	    (total_len > qup->out_fifo_sz || total_len > qup->in_fifo_sz)) {
1556 		qup->use_dma = true;
1557 	} else {
1558 		qup->blk.is_tx_blk_mode = max_tx_len > qup->out_fifo_sz -
1559 			QUP_MAX_TAGS_LEN;
1560 		qup->blk.is_rx_blk_mode = max_rx_len > qup->in_fifo_sz -
1561 			READ_RX_TAGS_LEN;
1562 	}
1563 
1564 	return 0;
1565 }
1566 
qup_i2c_xfer_v2(struct i2c_adapter * adap,struct i2c_msg msgs[],int num)1567 static int qup_i2c_xfer_v2(struct i2c_adapter *adap,
1568 			   struct i2c_msg msgs[],
1569 			   int num)
1570 {
1571 	struct qup_i2c_dev *qup = i2c_get_adapdata(adap);
1572 	int ret, idx = 0;
1573 
1574 	qup->bus_err = 0;
1575 	qup->qup_err = 0;
1576 
1577 	ret = pm_runtime_get_sync(qup->dev);
1578 	if (ret < 0)
1579 		goto out;
1580 
1581 	ret = qup_i2c_determine_mode_v2(qup, msgs, num);
1582 	if (ret)
1583 		goto out;
1584 
1585 	writel(1, qup->base + QUP_SW_RESET);
1586 	ret = qup_i2c_poll_state(qup, QUP_RESET_STATE);
1587 	if (ret)
1588 		goto out;
1589 
1590 	/* Configure QUP as I2C mini core */
1591 	writel(I2C_MINI_CORE | I2C_N_VAL_V2, qup->base + QUP_CONFIG);
1592 	writel(QUP_V2_TAGS_EN, qup->base + QUP_I2C_MASTER_GEN);
1593 
1594 	if (qup_i2c_poll_state_i2c_master(qup)) {
1595 		ret = -EIO;
1596 		goto out;
1597 	}
1598 
1599 	if (qup->use_dma) {
1600 		reinit_completion(&qup->xfer);
1601 		ret = qup_i2c_bam_xfer(adap, &msgs[0], num);
1602 		qup->use_dma = false;
1603 	} else {
1604 		qup_i2c_conf_mode_v2(qup);
1605 
1606 		for (idx = 0; idx < num; idx++) {
1607 			qup->msg = &msgs[idx];
1608 			qup->is_last = idx == (num - 1);
1609 
1610 			ret = qup_i2c_xfer_v2_msg(qup, idx,
1611 					!!(msgs[idx].flags & I2C_M_RD));
1612 			if (ret)
1613 				break;
1614 		}
1615 		qup->msg = NULL;
1616 	}
1617 
1618 	if (!ret)
1619 		ret = qup_i2c_bus_active(qup, ONE_BYTE);
1620 
1621 	if (!ret)
1622 		qup_i2c_change_state(qup, QUP_RESET_STATE);
1623 
1624 	if (ret == 0)
1625 		ret = num;
1626 out:
1627 	pm_runtime_mark_last_busy(qup->dev);
1628 	pm_runtime_put_autosuspend(qup->dev);
1629 
1630 	return ret;
1631 }
1632 
qup_i2c_func(struct i2c_adapter * adap)1633 static u32 qup_i2c_func(struct i2c_adapter *adap)
1634 {
1635 	return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL_ALL & ~I2C_FUNC_SMBUS_QUICK);
1636 }
1637 
1638 static const struct i2c_algorithm qup_i2c_algo = {
1639 	.master_xfer	= qup_i2c_xfer,
1640 	.functionality	= qup_i2c_func,
1641 };
1642 
1643 static const struct i2c_algorithm qup_i2c_algo_v2 = {
1644 	.master_xfer	= qup_i2c_xfer_v2,
1645 	.functionality	= qup_i2c_func,
1646 };
1647 
1648 /*
1649  * The QUP block will issue a NACK and STOP on the bus when reaching
1650  * the end of the read, the length of the read is specified as one byte
1651  * which limits the possible read to 256 (QUP_READ_LIMIT) bytes.
1652  */
1653 static const struct i2c_adapter_quirks qup_i2c_quirks = {
1654 	.flags = I2C_AQ_NO_ZERO_LEN,
1655 	.max_read_len = QUP_READ_LIMIT,
1656 };
1657 
1658 static const struct i2c_adapter_quirks qup_i2c_quirks_v2 = {
1659 	.flags = I2C_AQ_NO_ZERO_LEN,
1660 };
1661 
qup_i2c_enable_clocks(struct qup_i2c_dev * qup)1662 static void qup_i2c_enable_clocks(struct qup_i2c_dev *qup)
1663 {
1664 	clk_prepare_enable(qup->clk);
1665 	clk_prepare_enable(qup->pclk);
1666 }
1667 
qup_i2c_disable_clocks(struct qup_i2c_dev * qup)1668 static void qup_i2c_disable_clocks(struct qup_i2c_dev *qup)
1669 {
1670 	u32 config;
1671 
1672 	qup_i2c_change_state(qup, QUP_RESET_STATE);
1673 	clk_disable_unprepare(qup->clk);
1674 	config = readl(qup->base + QUP_CONFIG);
1675 	config |= QUP_CLOCK_AUTO_GATE;
1676 	writel(config, qup->base + QUP_CONFIG);
1677 	qup_i2c_vote_bw(qup, 0);
1678 	clk_disable_unprepare(qup->pclk);
1679 }
1680 
1681 static const struct acpi_device_id qup_i2c_acpi_match[] = {
1682 	{ "QCOM8010"},
1683 	{ },
1684 };
1685 MODULE_DEVICE_TABLE(acpi, qup_i2c_acpi_match);
1686 
qup_i2c_probe(struct platform_device * pdev)1687 static int qup_i2c_probe(struct platform_device *pdev)
1688 {
1689 	static const int blk_sizes[] = {4, 16, 32};
1690 	struct qup_i2c_dev *qup;
1691 	unsigned long one_bit_t;
1692 	u32 io_mode, hw_ver, size;
1693 	int ret, fs_div, hs_div;
1694 	u32 src_clk_freq = DEFAULT_SRC_CLK;
1695 	u32 clk_freq = DEFAULT_CLK_FREQ;
1696 	int blocks;
1697 	bool is_qup_v1;
1698 
1699 	qup = devm_kzalloc(&pdev->dev, sizeof(*qup), GFP_KERNEL);
1700 	if (!qup)
1701 		return -ENOMEM;
1702 
1703 	qup->dev = &pdev->dev;
1704 	init_completion(&qup->xfer);
1705 	platform_set_drvdata(pdev, qup);
1706 
1707 	if (scl_freq) {
1708 		dev_notice(qup->dev, "Using override frequency of %u\n", scl_freq);
1709 		clk_freq = scl_freq;
1710 	} else {
1711 		ret = device_property_read_u32(qup->dev, "clock-frequency", &clk_freq);
1712 		if (ret) {
1713 			dev_notice(qup->dev, "using default clock-frequency %d",
1714 				DEFAULT_CLK_FREQ);
1715 		}
1716 	}
1717 
1718 	if (of_device_is_compatible(pdev->dev.of_node, "qcom,i2c-qup-v1.1.1")) {
1719 		qup->adap.algo = &qup_i2c_algo;
1720 		qup->adap.quirks = &qup_i2c_quirks;
1721 		is_qup_v1 = true;
1722 	} else {
1723 		qup->adap.algo = &qup_i2c_algo_v2;
1724 		qup->adap.quirks = &qup_i2c_quirks_v2;
1725 		is_qup_v1 = false;
1726 		if (acpi_match_device(qup_i2c_acpi_match, qup->dev))
1727 			goto nodma;
1728 		else
1729 			ret = qup_i2c_req_dma(qup);
1730 
1731 		if (ret == -EPROBE_DEFER)
1732 			goto fail_dma;
1733 		else if (ret != 0)
1734 			goto nodma;
1735 
1736 		qup->max_xfer_sg_len = (MX_BLOCKS << 1);
1737 		blocks = (MX_DMA_BLOCKS << 1) + 1;
1738 		qup->btx.sg = devm_kcalloc(&pdev->dev,
1739 					   blocks, sizeof(*qup->btx.sg),
1740 					   GFP_KERNEL);
1741 		if (!qup->btx.sg) {
1742 			ret = -ENOMEM;
1743 			goto fail_dma;
1744 		}
1745 		sg_init_table(qup->btx.sg, blocks);
1746 
1747 		qup->brx.sg = devm_kcalloc(&pdev->dev,
1748 					   blocks, sizeof(*qup->brx.sg),
1749 					   GFP_KERNEL);
1750 		if (!qup->brx.sg) {
1751 			ret = -ENOMEM;
1752 			goto fail_dma;
1753 		}
1754 		sg_init_table(qup->brx.sg, blocks);
1755 
1756 		/* 2 tag bytes for each block + 5 for start, stop tags */
1757 		size = blocks * 2 + 5;
1758 
1759 		qup->start_tag.start = devm_kzalloc(&pdev->dev,
1760 						    size, GFP_KERNEL);
1761 		if (!qup->start_tag.start) {
1762 			ret = -ENOMEM;
1763 			goto fail_dma;
1764 		}
1765 
1766 		qup->brx.tag.start = devm_kzalloc(&pdev->dev, 2, GFP_KERNEL);
1767 		if (!qup->brx.tag.start) {
1768 			ret = -ENOMEM;
1769 			goto fail_dma;
1770 		}
1771 
1772 		qup->btx.tag.start = devm_kzalloc(&pdev->dev, 2, GFP_KERNEL);
1773 		if (!qup->btx.tag.start) {
1774 			ret = -ENOMEM;
1775 			goto fail_dma;
1776 		}
1777 		qup->is_dma = true;
1778 
1779 		qup->icc_path = devm_of_icc_get(&pdev->dev, NULL);
1780 		if (IS_ERR(qup->icc_path))
1781 			return dev_err_probe(&pdev->dev, PTR_ERR(qup->icc_path),
1782 					     "failed to get interconnect path\n");
1783 	}
1784 
1785 nodma:
1786 	/* We support frequencies up to FAST Mode Plus (1MHz) */
1787 	if (!clk_freq || clk_freq > I2C_MAX_FAST_MODE_PLUS_FREQ) {
1788 		dev_err(qup->dev, "clock frequency not supported %d\n",
1789 			clk_freq);
1790 		ret = -EINVAL;
1791 		goto fail_dma;
1792 	}
1793 
1794 	qup->base = devm_platform_ioremap_resource(pdev, 0);
1795 	if (IS_ERR(qup->base)) {
1796 		ret = PTR_ERR(qup->base);
1797 		goto fail_dma;
1798 	}
1799 
1800 	qup->irq = platform_get_irq(pdev, 0);
1801 	if (qup->irq < 0) {
1802 		ret = qup->irq;
1803 		goto fail_dma;
1804 	}
1805 
1806 	if (has_acpi_companion(qup->dev)) {
1807 		ret = device_property_read_u32(qup->dev,
1808 				"src-clock-hz", &src_clk_freq);
1809 		if (ret) {
1810 			dev_notice(qup->dev, "using default src-clock-hz %d",
1811 				DEFAULT_SRC_CLK);
1812 		}
1813 		ACPI_COMPANION_SET(&qup->adap.dev, ACPI_COMPANION(qup->dev));
1814 	} else {
1815 		qup->clk = devm_clk_get(qup->dev, "core");
1816 		if (IS_ERR(qup->clk)) {
1817 			dev_err(qup->dev, "Could not get core clock\n");
1818 			ret = PTR_ERR(qup->clk);
1819 			goto fail_dma;
1820 		}
1821 
1822 		qup->pclk = devm_clk_get(qup->dev, "iface");
1823 		if (IS_ERR(qup->pclk)) {
1824 			dev_err(qup->dev, "Could not get iface clock\n");
1825 			ret = PTR_ERR(qup->pclk);
1826 			goto fail_dma;
1827 		}
1828 		qup_i2c_enable_clocks(qup);
1829 		src_clk_freq = clk_get_rate(qup->clk);
1830 	}
1831 	qup->src_clk_freq = src_clk_freq;
1832 
1833 	/*
1834 	 * Bootloaders might leave a pending interrupt on certain QUP's,
1835 	 * so we reset the core before registering for interrupts.
1836 	 */
1837 	writel(1, qup->base + QUP_SW_RESET);
1838 	ret = qup_i2c_poll_state_valid(qup);
1839 	if (ret)
1840 		goto fail;
1841 
1842 	ret = devm_request_irq(qup->dev, qup->irq, qup_i2c_interrupt,
1843 			       IRQF_TRIGGER_HIGH | IRQF_NO_AUTOEN,
1844 			       "i2c_qup", qup);
1845 	if (ret) {
1846 		dev_err(qup->dev, "Request %d IRQ failed\n", qup->irq);
1847 		goto fail;
1848 	}
1849 
1850 	hw_ver = readl(qup->base + QUP_HW_VERSION);
1851 	dev_dbg(qup->dev, "Revision %x\n", hw_ver);
1852 
1853 	io_mode = readl(qup->base + QUP_IO_MODE);
1854 
1855 	/*
1856 	 * The block/fifo size w.r.t. 'actual data' is 1/2 due to 'tag'
1857 	 * associated with each byte written/received
1858 	 */
1859 	size = QUP_OUTPUT_BLOCK_SIZE(io_mode);
1860 	if (size >= ARRAY_SIZE(blk_sizes)) {
1861 		ret = -EIO;
1862 		goto fail;
1863 	}
1864 	qup->out_blk_sz = blk_sizes[size];
1865 
1866 	size = QUP_INPUT_BLOCK_SIZE(io_mode);
1867 	if (size >= ARRAY_SIZE(blk_sizes)) {
1868 		ret = -EIO;
1869 		goto fail;
1870 	}
1871 	qup->in_blk_sz = blk_sizes[size];
1872 
1873 	if (is_qup_v1) {
1874 		/*
1875 		 * in QUP v1, QUP_CONFIG uses N as 15 i.e 16 bits constitutes a
1876 		 * single transfer but the block size is in bytes so divide the
1877 		 * in_blk_sz and out_blk_sz by 2
1878 		 */
1879 		qup->in_blk_sz /= 2;
1880 		qup->out_blk_sz /= 2;
1881 		qup->write_tx_fifo = qup_i2c_write_tx_fifo_v1;
1882 		qup->read_rx_fifo = qup_i2c_read_rx_fifo_v1;
1883 		qup->write_rx_tags = qup_i2c_write_rx_tags_v1;
1884 	} else {
1885 		qup->write_tx_fifo = qup_i2c_write_tx_fifo_v2;
1886 		qup->read_rx_fifo = qup_i2c_read_rx_fifo_v2;
1887 		qup->write_rx_tags = qup_i2c_write_rx_tags_v2;
1888 	}
1889 
1890 	size = QUP_OUTPUT_FIFO_SIZE(io_mode);
1891 	qup->out_fifo_sz = qup->out_blk_sz * (2 << size);
1892 
1893 	size = QUP_INPUT_FIFO_SIZE(io_mode);
1894 	qup->in_fifo_sz = qup->in_blk_sz * (2 << size);
1895 
1896 	hs_div = 3;
1897 	if (clk_freq <= I2C_MAX_STANDARD_MODE_FREQ) {
1898 		fs_div = ((src_clk_freq / clk_freq) / 2) - 3;
1899 		qup->clk_ctl = (hs_div << 8) | (fs_div & 0xff);
1900 	} else {
1901 		/* 33%/66% duty cycle */
1902 		fs_div = ((src_clk_freq / clk_freq) - 6) * 2 / 3;
1903 		qup->clk_ctl = ((fs_div / 2) << 16) | (hs_div << 8) | (fs_div & 0xff);
1904 	}
1905 
1906 	/*
1907 	 * Time it takes for a byte to be clocked out on the bus.
1908 	 * Each byte takes 9 clock cycles (8 bits + 1 ack).
1909 	 */
1910 	one_bit_t = (USEC_PER_SEC / clk_freq) + 1;
1911 	qup->one_byte_t = one_bit_t * 9;
1912 	qup->xfer_timeout = TOUT_MIN * HZ +
1913 		usecs_to_jiffies(MX_DMA_TX_RX_LEN * qup->one_byte_t);
1914 
1915 	dev_dbg(qup->dev, "IN:block:%d, fifo:%d, OUT:block:%d, fifo:%d\n",
1916 		qup->in_blk_sz, qup->in_fifo_sz,
1917 		qup->out_blk_sz, qup->out_fifo_sz);
1918 
1919 	i2c_set_adapdata(&qup->adap, qup);
1920 	qup->adap.dev.parent = qup->dev;
1921 	qup->adap.dev.of_node = pdev->dev.of_node;
1922 	qup->is_last = true;
1923 
1924 	strscpy(qup->adap.name, "QUP I2C adapter", sizeof(qup->adap.name));
1925 
1926 	pm_runtime_set_autosuspend_delay(qup->dev, MSEC_PER_SEC);
1927 	pm_runtime_use_autosuspend(qup->dev);
1928 	pm_runtime_set_active(qup->dev);
1929 	pm_runtime_enable(qup->dev);
1930 
1931 	ret = i2c_add_adapter(&qup->adap);
1932 	if (ret)
1933 		goto fail_runtime;
1934 
1935 	return 0;
1936 
1937 fail_runtime:
1938 	pm_runtime_disable(qup->dev);
1939 	pm_runtime_set_suspended(qup->dev);
1940 fail:
1941 	qup_i2c_disable_clocks(qup);
1942 fail_dma:
1943 	if (qup->btx.dma)
1944 		dma_release_channel(qup->btx.dma);
1945 	if (qup->brx.dma)
1946 		dma_release_channel(qup->brx.dma);
1947 	return ret;
1948 }
1949 
qup_i2c_remove(struct platform_device * pdev)1950 static void qup_i2c_remove(struct platform_device *pdev)
1951 {
1952 	struct qup_i2c_dev *qup = platform_get_drvdata(pdev);
1953 
1954 	if (qup->is_dma) {
1955 		dma_release_channel(qup->btx.dma);
1956 		dma_release_channel(qup->brx.dma);
1957 	}
1958 
1959 	disable_irq(qup->irq);
1960 	qup_i2c_disable_clocks(qup);
1961 	i2c_del_adapter(&qup->adap);
1962 	pm_runtime_disable(qup->dev);
1963 	pm_runtime_set_suspended(qup->dev);
1964 }
1965 
qup_i2c_pm_suspend_runtime(struct device * device)1966 static int qup_i2c_pm_suspend_runtime(struct device *device)
1967 {
1968 	struct qup_i2c_dev *qup = dev_get_drvdata(device);
1969 
1970 	dev_dbg(device, "pm_runtime: suspending...\n");
1971 	qup_i2c_disable_clocks(qup);
1972 	return 0;
1973 }
1974 
qup_i2c_pm_resume_runtime(struct device * device)1975 static int qup_i2c_pm_resume_runtime(struct device *device)
1976 {
1977 	struct qup_i2c_dev *qup = dev_get_drvdata(device);
1978 
1979 	dev_dbg(device, "pm_runtime: resuming...\n");
1980 	qup_i2c_enable_clocks(qup);
1981 	return 0;
1982 }
1983 
qup_i2c_suspend(struct device * device)1984 static int qup_i2c_suspend(struct device *device)
1985 {
1986 	if (!pm_runtime_suspended(device))
1987 		return qup_i2c_pm_suspend_runtime(device);
1988 	return 0;
1989 }
1990 
qup_i2c_resume(struct device * device)1991 static int qup_i2c_resume(struct device *device)
1992 {
1993 	qup_i2c_pm_resume_runtime(device);
1994 	pm_runtime_mark_last_busy(device);
1995 	pm_request_autosuspend(device);
1996 	return 0;
1997 }
1998 
1999 static const struct dev_pm_ops qup_i2c_qup_pm_ops = {
2000 	SYSTEM_SLEEP_PM_OPS(qup_i2c_suspend, qup_i2c_resume)
2001 	RUNTIME_PM_OPS(qup_i2c_pm_suspend_runtime,
2002 		       qup_i2c_pm_resume_runtime, NULL)
2003 };
2004 
2005 static const struct of_device_id qup_i2c_dt_match[] = {
2006 	{ .compatible = "qcom,i2c-qup-v1.1.1" },
2007 	{ .compatible = "qcom,i2c-qup-v2.1.1" },
2008 	{ .compatible = "qcom,i2c-qup-v2.2.1" },
2009 	{}
2010 };
2011 MODULE_DEVICE_TABLE(of, qup_i2c_dt_match);
2012 
2013 static struct platform_driver qup_i2c_driver = {
2014 	.probe  = qup_i2c_probe,
2015 	.remove_new = qup_i2c_remove,
2016 	.driver = {
2017 		.name = "i2c_qup",
2018 		.pm = pm_ptr(&qup_i2c_qup_pm_ops),
2019 		.of_match_table = qup_i2c_dt_match,
2020 		.acpi_match_table = ACPI_PTR(qup_i2c_acpi_match),
2021 	},
2022 };
2023 
2024 module_platform_driver(qup_i2c_driver);
2025 
2026 MODULE_LICENSE("GPL v2");
2027 MODULE_ALIAS("platform:i2c_qup");
2028