1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (c) 2017-2018, The Linux Foundation. All rights reserved.
3 
4 #include <linux/acpi.h>
5 #include <linux/clk.h>
6 #include <linux/dmaengine.h>
7 #include <linux/dma-mapping.h>
8 #include <linux/dma/qcom-gpi-dma.h>
9 #include <linux/err.h>
10 #include <linux/i2c.h>
11 #include <linux/interrupt.h>
12 #include <linux/io.h>
13 #include <linux/module.h>
14 #include <linux/of.h>
15 #include <linux/platform_device.h>
16 #include <linux/pm_runtime.h>
17 #include <linux/qcom-geni-se.h>
18 #include <linux/spinlock.h>
19 
20 #define SE_I2C_TX_TRANS_LEN		0x26c
21 #define SE_I2C_RX_TRANS_LEN		0x270
22 #define SE_I2C_SCL_COUNTERS		0x278
23 
24 #define SE_I2C_ERR  (M_CMD_OVERRUN_EN | M_ILLEGAL_CMD_EN | M_CMD_FAILURE_EN |\
25 			M_GP_IRQ_1_EN | M_GP_IRQ_3_EN | M_GP_IRQ_4_EN)
26 #define SE_I2C_ABORT		BIT(1)
27 
28 /* M_CMD OP codes for I2C */
29 #define I2C_WRITE		0x1
30 #define I2C_READ		0x2
31 #define I2C_WRITE_READ		0x3
32 #define I2C_ADDR_ONLY		0x4
33 #define I2C_BUS_CLEAR		0x6
34 #define I2C_STOP_ON_BUS		0x7
35 /* M_CMD params for I2C */
36 #define PRE_CMD_DELAY		BIT(0)
37 #define TIMESTAMP_BEFORE	BIT(1)
38 #define STOP_STRETCH		BIT(2)
39 #define TIMESTAMP_AFTER		BIT(3)
40 #define POST_COMMAND_DELAY	BIT(4)
41 #define IGNORE_ADD_NACK		BIT(6)
42 #define READ_FINISHED_WITH_ACK	BIT(7)
43 #define BYPASS_ADDR_PHASE	BIT(8)
44 #define SLV_ADDR_MSK		GENMASK(15, 9)
45 #define SLV_ADDR_SHFT		9
46 /* I2C SCL COUNTER fields */
47 #define HIGH_COUNTER_MSK	GENMASK(29, 20)
48 #define HIGH_COUNTER_SHFT	20
49 #define LOW_COUNTER_MSK		GENMASK(19, 10)
50 #define LOW_COUNTER_SHFT	10
51 #define CYCLE_COUNTER_MSK	GENMASK(9, 0)
52 
53 #define I2C_PACK_TX		BIT(0)
54 #define I2C_PACK_RX		BIT(1)
55 
56 enum geni_i2c_err_code {
57 	GP_IRQ0,
58 	NACK,
59 	GP_IRQ2,
60 	BUS_PROTO,
61 	ARB_LOST,
62 	GP_IRQ5,
63 	GENI_OVERRUN,
64 	GENI_ILLEGAL_CMD,
65 	GENI_ABORT_DONE,
66 	GENI_TIMEOUT,
67 };
68 
69 #define DM_I2C_CB_ERR		((BIT(NACK) | BIT(BUS_PROTO) | BIT(ARB_LOST)) \
70 									<< 5)
71 
72 #define I2C_AUTO_SUSPEND_DELAY	250
73 #define KHZ(freq)		(1000 * freq)
74 #define PACKING_BYTES_PW	4
75 
76 #define ABORT_TIMEOUT		HZ
77 #define XFER_TIMEOUT		HZ
78 #define RST_TIMEOUT		HZ
79 
80 struct geni_i2c_dev {
81 	struct geni_se se;
82 	u32 tx_wm;
83 	int irq;
84 	int err;
85 	struct i2c_adapter adap;
86 	struct completion done;
87 	struct i2c_msg *cur;
88 	int cur_wr;
89 	int cur_rd;
90 	spinlock_t lock;
91 	u32 clk_freq_out;
92 	const struct geni_i2c_clk_fld *clk_fld;
93 	int suspended;
94 	void *dma_buf;
95 	size_t xfer_len;
96 	dma_addr_t dma_addr;
97 	struct dma_chan *tx_c;
98 	struct dma_chan *rx_c;
99 	bool gpi_mode;
100 };
101 
102 struct geni_i2c_err_log {
103 	int err;
104 	const char *msg;
105 };
106 
107 static const struct geni_i2c_err_log gi2c_log[] = {
108 	[GP_IRQ0] = {-EIO, "Unknown I2C err GP_IRQ0"},
109 	[NACK] = {-ENXIO, "NACK: slv unresponsive, check its power/reset-ln"},
110 	[GP_IRQ2] = {-EIO, "Unknown I2C err GP IRQ2"},
111 	[BUS_PROTO] = {-EPROTO, "Bus proto err, noisy/unexpected start/stop"},
112 	[ARB_LOST] = {-EAGAIN, "Bus arbitration lost, clock line undriveable"},
113 	[GP_IRQ5] = {-EIO, "Unknown I2C err GP IRQ5"},
114 	[GENI_OVERRUN] = {-EIO, "Cmd overrun, check GENI cmd-state machine"},
115 	[GENI_ILLEGAL_CMD] = {-EIO, "Illegal cmd, check GENI cmd-state machine"},
116 	[GENI_ABORT_DONE] = {-ETIMEDOUT, "Abort after timeout successful"},
117 	[GENI_TIMEOUT] = {-ETIMEDOUT, "I2C TXN timed out"},
118 };
119 
120 struct geni_i2c_clk_fld {
121 	u32	clk_freq_out;
122 	u8	clk_div;
123 	u8	t_high_cnt;
124 	u8	t_low_cnt;
125 	u8	t_cycle_cnt;
126 };
127 
128 /*
129  * Hardware uses the underlying formula to calculate time periods of
130  * SCL clock cycle. Firmware uses some additional cycles excluded from the
131  * below formula and it is confirmed that the time periods are within
132  * specification limits.
133  *
134  * time of high period of SCL: t_high = (t_high_cnt * clk_div) / source_clock
135  * time of low period of SCL: t_low = (t_low_cnt * clk_div) / source_clock
136  * time of full period of SCL: t_cycle = (t_cycle_cnt * clk_div) / source_clock
137  * clk_freq_out = t / t_cycle
138  * source_clock = 19.2 MHz
139  */
140 static const struct geni_i2c_clk_fld geni_i2c_clk_map[] = {
141 	{KHZ(100), 7, 10, 11, 26},
142 	{KHZ(400), 2,  5, 12, 24},
143 	{KHZ(1000), 1, 3,  9, 18},
144 };
145 
146 static int geni_i2c_clk_map_idx(struct geni_i2c_dev *gi2c)
147 {
148 	int i;
149 	const struct geni_i2c_clk_fld *itr = geni_i2c_clk_map;
150 
151 	for (i = 0; i < ARRAY_SIZE(geni_i2c_clk_map); i++, itr++) {
152 		if (itr->clk_freq_out == gi2c->clk_freq_out) {
153 			gi2c->clk_fld = itr;
154 			return 0;
155 		}
156 	}
157 	return -EINVAL;
158 }
159 
160 static void qcom_geni_i2c_conf(struct geni_i2c_dev *gi2c)
161 {
162 	const struct geni_i2c_clk_fld *itr = gi2c->clk_fld;
163 	u32 val;
164 
165 	writel_relaxed(0, gi2c->se.base + SE_GENI_CLK_SEL);
166 
167 	val = (itr->clk_div << CLK_DIV_SHFT) | SER_CLK_EN;
168 	writel_relaxed(val, gi2c->se.base + GENI_SER_M_CLK_CFG);
169 
170 	val = itr->t_high_cnt << HIGH_COUNTER_SHFT;
171 	val |= itr->t_low_cnt << LOW_COUNTER_SHFT;
172 	val |= itr->t_cycle_cnt;
173 	writel_relaxed(val, gi2c->se.base + SE_I2C_SCL_COUNTERS);
174 }
175 
176 static void geni_i2c_err_misc(struct geni_i2c_dev *gi2c)
177 {
178 	u32 m_cmd = readl_relaxed(gi2c->se.base + SE_GENI_M_CMD0);
179 	u32 m_stat = readl_relaxed(gi2c->se.base + SE_GENI_M_IRQ_STATUS);
180 	u32 geni_s = readl_relaxed(gi2c->se.base + SE_GENI_STATUS);
181 	u32 geni_ios = readl_relaxed(gi2c->se.base + SE_GENI_IOS);
182 	u32 dma = readl_relaxed(gi2c->se.base + SE_GENI_DMA_MODE_EN);
183 	u32 rx_st, tx_st;
184 
185 	if (dma) {
186 		rx_st = readl_relaxed(gi2c->se.base + SE_DMA_RX_IRQ_STAT);
187 		tx_st = readl_relaxed(gi2c->se.base + SE_DMA_TX_IRQ_STAT);
188 	} else {
189 		rx_st = readl_relaxed(gi2c->se.base + SE_GENI_RX_FIFO_STATUS);
190 		tx_st = readl_relaxed(gi2c->se.base + SE_GENI_TX_FIFO_STATUS);
191 	}
192 	dev_dbg(gi2c->se.dev, "DMA:%d tx_stat:0x%x, rx_stat:0x%x, irq-stat:0x%x\n",
193 		dma, tx_st, rx_st, m_stat);
194 	dev_dbg(gi2c->se.dev, "m_cmd:0x%x, geni_status:0x%x, geni_ios:0x%x\n",
195 		m_cmd, geni_s, geni_ios);
196 }
197 
198 static void geni_i2c_err(struct geni_i2c_dev *gi2c, int err)
199 {
200 	if (!gi2c->err)
201 		gi2c->err = gi2c_log[err].err;
202 	if (gi2c->cur)
203 		dev_dbg(gi2c->se.dev, "len:%d, slv-addr:0x%x, RD/WR:%d\n",
204 			gi2c->cur->len, gi2c->cur->addr, gi2c->cur->flags);
205 
206 	if (err != NACK && err != GENI_ABORT_DONE) {
207 		dev_err(gi2c->se.dev, "%s\n", gi2c_log[err].msg);
208 		geni_i2c_err_misc(gi2c);
209 	}
210 }
211 
212 static irqreturn_t geni_i2c_irq(int irq, void *dev)
213 {
214 	struct geni_i2c_dev *gi2c = dev;
215 	void __iomem *base = gi2c->se.base;
216 	int j, p;
217 	u32 m_stat;
218 	u32 rx_st;
219 	u32 dm_tx_st;
220 	u32 dm_rx_st;
221 	u32 dma;
222 	u32 val;
223 	struct i2c_msg *cur;
224 
225 	spin_lock(&gi2c->lock);
226 	m_stat = readl_relaxed(base + SE_GENI_M_IRQ_STATUS);
227 	rx_st = readl_relaxed(base + SE_GENI_RX_FIFO_STATUS);
228 	dm_tx_st = readl_relaxed(base + SE_DMA_TX_IRQ_STAT);
229 	dm_rx_st = readl_relaxed(base + SE_DMA_RX_IRQ_STAT);
230 	dma = readl_relaxed(base + SE_GENI_DMA_MODE_EN);
231 	cur = gi2c->cur;
232 
233 	if (!cur ||
234 	    m_stat & (M_CMD_FAILURE_EN | M_CMD_ABORT_EN) ||
235 	    dm_rx_st & (DM_I2C_CB_ERR)) {
236 		if (m_stat & M_GP_IRQ_1_EN)
237 			geni_i2c_err(gi2c, NACK);
238 		if (m_stat & M_GP_IRQ_3_EN)
239 			geni_i2c_err(gi2c, BUS_PROTO);
240 		if (m_stat & M_GP_IRQ_4_EN)
241 			geni_i2c_err(gi2c, ARB_LOST);
242 		if (m_stat & M_CMD_OVERRUN_EN)
243 			geni_i2c_err(gi2c, GENI_OVERRUN);
244 		if (m_stat & M_ILLEGAL_CMD_EN)
245 			geni_i2c_err(gi2c, GENI_ILLEGAL_CMD);
246 		if (m_stat & M_CMD_ABORT_EN)
247 			geni_i2c_err(gi2c, GENI_ABORT_DONE);
248 		if (m_stat & M_GP_IRQ_0_EN)
249 			geni_i2c_err(gi2c, GP_IRQ0);
250 
251 		/* Disable the TX Watermark interrupt to stop TX */
252 		if (!dma)
253 			writel_relaxed(0, base + SE_GENI_TX_WATERMARK_REG);
254 	} else if (dma) {
255 		dev_dbg(gi2c->se.dev, "i2c dma tx:0x%x, dma rx:0x%x\n",
256 			dm_tx_st, dm_rx_st);
257 	} else if (cur->flags & I2C_M_RD &&
258 		   m_stat & (M_RX_FIFO_WATERMARK_EN | M_RX_FIFO_LAST_EN)) {
259 		u32 rxcnt = rx_st & RX_FIFO_WC_MSK;
260 
261 		for (j = 0; j < rxcnt; j++) {
262 			p = 0;
263 			val = readl_relaxed(base + SE_GENI_RX_FIFOn);
264 			while (gi2c->cur_rd < cur->len && p < sizeof(val)) {
265 				cur->buf[gi2c->cur_rd++] = val & 0xff;
266 				val >>= 8;
267 				p++;
268 			}
269 			if (gi2c->cur_rd == cur->len)
270 				break;
271 		}
272 	} else if (!(cur->flags & I2C_M_RD) &&
273 		   m_stat & M_TX_FIFO_WATERMARK_EN) {
274 		for (j = 0; j < gi2c->tx_wm; j++) {
275 			u32 temp;
276 
277 			val = 0;
278 			p = 0;
279 			while (gi2c->cur_wr < cur->len && p < sizeof(val)) {
280 				temp = cur->buf[gi2c->cur_wr++];
281 				val |= temp << (p * 8);
282 				p++;
283 			}
284 			writel_relaxed(val, base + SE_GENI_TX_FIFOn);
285 			/* TX Complete, Disable the TX Watermark interrupt */
286 			if (gi2c->cur_wr == cur->len) {
287 				writel_relaxed(0, base + SE_GENI_TX_WATERMARK_REG);
288 				break;
289 			}
290 		}
291 	}
292 
293 	if (m_stat)
294 		writel_relaxed(m_stat, base + SE_GENI_M_IRQ_CLEAR);
295 
296 	if (dma && dm_tx_st)
297 		writel_relaxed(dm_tx_st, base + SE_DMA_TX_IRQ_CLR);
298 	if (dma && dm_rx_st)
299 		writel_relaxed(dm_rx_st, base + SE_DMA_RX_IRQ_CLR);
300 
301 	/* if this is err with done-bit not set, handle that through timeout. */
302 	if (m_stat & M_CMD_DONE_EN || m_stat & M_CMD_ABORT_EN ||
303 	    dm_tx_st & TX_DMA_DONE || dm_tx_st & TX_RESET_DONE ||
304 	    dm_rx_st & RX_DMA_DONE || dm_rx_st & RX_RESET_DONE)
305 		complete(&gi2c->done);
306 
307 	spin_unlock(&gi2c->lock);
308 
309 	return IRQ_HANDLED;
310 }
311 
312 static void geni_i2c_abort_xfer(struct geni_i2c_dev *gi2c)
313 {
314 	u32 val;
315 	unsigned long time_left = ABORT_TIMEOUT;
316 	unsigned long flags;
317 
318 	spin_lock_irqsave(&gi2c->lock, flags);
319 	geni_i2c_err(gi2c, GENI_TIMEOUT);
320 	gi2c->cur = NULL;
321 	geni_se_abort_m_cmd(&gi2c->se);
322 	spin_unlock_irqrestore(&gi2c->lock, flags);
323 	do {
324 		time_left = wait_for_completion_timeout(&gi2c->done, time_left);
325 		val = readl_relaxed(gi2c->se.base + SE_GENI_M_IRQ_STATUS);
326 	} while (!(val & M_CMD_ABORT_EN) && time_left);
327 
328 	if (!(val & M_CMD_ABORT_EN))
329 		dev_err(gi2c->se.dev, "Timeout abort_m_cmd\n");
330 }
331 
332 static void geni_i2c_rx_fsm_rst(struct geni_i2c_dev *gi2c)
333 {
334 	u32 val;
335 	unsigned long time_left = RST_TIMEOUT;
336 
337 	writel_relaxed(1, gi2c->se.base + SE_DMA_RX_FSM_RST);
338 	do {
339 		time_left = wait_for_completion_timeout(&gi2c->done, time_left);
340 		val = readl_relaxed(gi2c->se.base + SE_DMA_RX_IRQ_STAT);
341 	} while (!(val & RX_RESET_DONE) && time_left);
342 
343 	if (!(val & RX_RESET_DONE))
344 		dev_err(gi2c->se.dev, "Timeout resetting RX_FSM\n");
345 }
346 
347 static void geni_i2c_tx_fsm_rst(struct geni_i2c_dev *gi2c)
348 {
349 	u32 val;
350 	unsigned long time_left = RST_TIMEOUT;
351 
352 	writel_relaxed(1, gi2c->se.base + SE_DMA_TX_FSM_RST);
353 	do {
354 		time_left = wait_for_completion_timeout(&gi2c->done, time_left);
355 		val = readl_relaxed(gi2c->se.base + SE_DMA_TX_IRQ_STAT);
356 	} while (!(val & TX_RESET_DONE) && time_left);
357 
358 	if (!(val & TX_RESET_DONE))
359 		dev_err(gi2c->se.dev, "Timeout resetting TX_FSM\n");
360 }
361 
362 static void geni_i2c_rx_msg_cleanup(struct geni_i2c_dev *gi2c,
363 				     struct i2c_msg *cur)
364 {
365 	gi2c->cur_rd = 0;
366 	if (gi2c->dma_buf) {
367 		if (gi2c->err)
368 			geni_i2c_rx_fsm_rst(gi2c);
369 		geni_se_rx_dma_unprep(&gi2c->se, gi2c->dma_addr, gi2c->xfer_len);
370 		i2c_put_dma_safe_msg_buf(gi2c->dma_buf, cur, !gi2c->err);
371 	}
372 }
373 
374 static void geni_i2c_tx_msg_cleanup(struct geni_i2c_dev *gi2c,
375 				     struct i2c_msg *cur)
376 {
377 	gi2c->cur_wr = 0;
378 	if (gi2c->dma_buf) {
379 		if (gi2c->err)
380 			geni_i2c_tx_fsm_rst(gi2c);
381 		geni_se_tx_dma_unprep(&gi2c->se, gi2c->dma_addr, gi2c->xfer_len);
382 		i2c_put_dma_safe_msg_buf(gi2c->dma_buf, cur, !gi2c->err);
383 	}
384 }
385 
386 static int geni_i2c_rx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
387 				u32 m_param)
388 {
389 	dma_addr_t rx_dma = 0;
390 	unsigned long time_left;
391 	void *dma_buf;
392 	struct geni_se *se = &gi2c->se;
393 	size_t len = msg->len;
394 	struct i2c_msg *cur;
395 
396 	dma_buf = i2c_get_dma_safe_msg_buf(msg, 32);
397 	if (dma_buf)
398 		geni_se_select_mode(se, GENI_SE_DMA);
399 	else
400 		geni_se_select_mode(se, GENI_SE_FIFO);
401 
402 	writel_relaxed(len, se->base + SE_I2C_RX_TRANS_LEN);
403 	geni_se_setup_m_cmd(se, I2C_READ, m_param);
404 
405 	if (dma_buf && geni_se_rx_dma_prep(se, dma_buf, len, &rx_dma)) {
406 		geni_se_select_mode(se, GENI_SE_FIFO);
407 		i2c_put_dma_safe_msg_buf(dma_buf, msg, false);
408 		dma_buf = NULL;
409 	} else {
410 		gi2c->xfer_len = len;
411 		gi2c->dma_addr = rx_dma;
412 		gi2c->dma_buf = dma_buf;
413 	}
414 
415 	cur = gi2c->cur;
416 	time_left = wait_for_completion_timeout(&gi2c->done, XFER_TIMEOUT);
417 	if (!time_left)
418 		geni_i2c_abort_xfer(gi2c);
419 
420 	geni_i2c_rx_msg_cleanup(gi2c, cur);
421 
422 	return gi2c->err;
423 }
424 
425 static int geni_i2c_tx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
426 				u32 m_param)
427 {
428 	dma_addr_t tx_dma = 0;
429 	unsigned long time_left;
430 	void *dma_buf;
431 	struct geni_se *se = &gi2c->se;
432 	size_t len = msg->len;
433 	struct i2c_msg *cur;
434 
435 	dma_buf = i2c_get_dma_safe_msg_buf(msg, 32);
436 	if (dma_buf)
437 		geni_se_select_mode(se, GENI_SE_DMA);
438 	else
439 		geni_se_select_mode(se, GENI_SE_FIFO);
440 
441 	writel_relaxed(len, se->base + SE_I2C_TX_TRANS_LEN);
442 	geni_se_setup_m_cmd(se, I2C_WRITE, m_param);
443 
444 	if (dma_buf && geni_se_tx_dma_prep(se, dma_buf, len, &tx_dma)) {
445 		geni_se_select_mode(se, GENI_SE_FIFO);
446 		i2c_put_dma_safe_msg_buf(dma_buf, msg, false);
447 		dma_buf = NULL;
448 	} else {
449 		gi2c->xfer_len = len;
450 		gi2c->dma_addr = tx_dma;
451 		gi2c->dma_buf = dma_buf;
452 	}
453 
454 	if (!dma_buf) /* Get FIFO IRQ */
455 		writel_relaxed(1, se->base + SE_GENI_TX_WATERMARK_REG);
456 
457 	cur = gi2c->cur;
458 	time_left = wait_for_completion_timeout(&gi2c->done, XFER_TIMEOUT);
459 	if (!time_left)
460 		geni_i2c_abort_xfer(gi2c);
461 
462 	geni_i2c_tx_msg_cleanup(gi2c, cur);
463 
464 	return gi2c->err;
465 }
466 
467 static void i2c_gpi_cb_result(void *cb, const struct dmaengine_result *result)
468 {
469 	struct geni_i2c_dev *gi2c = cb;
470 
471 	if (result->result != DMA_TRANS_NOERROR) {
472 		dev_err(gi2c->se.dev, "DMA txn failed:%d\n", result->result);
473 		gi2c->err = -EIO;
474 	} else if (result->residue) {
475 		dev_dbg(gi2c->se.dev, "DMA xfer has pending: %d\n", result->residue);
476 	}
477 
478 	complete(&gi2c->done);
479 }
480 
481 static void geni_i2c_gpi_unmap(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
482 			       void *tx_buf, dma_addr_t tx_addr,
483 			       void *rx_buf, dma_addr_t rx_addr)
484 {
485 	if (tx_buf) {
486 		dma_unmap_single(gi2c->se.dev->parent, tx_addr, msg->len, DMA_TO_DEVICE);
487 		i2c_put_dma_safe_msg_buf(tx_buf, msg, false);
488 	}
489 
490 	if (rx_buf) {
491 		dma_unmap_single(gi2c->se.dev->parent, rx_addr, msg->len, DMA_FROM_DEVICE);
492 		i2c_put_dma_safe_msg_buf(rx_buf, msg, false);
493 	}
494 }
495 
496 static int geni_i2c_gpi(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
497 			struct dma_slave_config *config, dma_addr_t *dma_addr_p,
498 			void **buf, unsigned int op, struct dma_chan *dma_chan)
499 {
500 	struct gpi_i2c_config *peripheral;
501 	unsigned int flags;
502 	void *dma_buf;
503 	dma_addr_t addr;
504 	enum dma_data_direction map_dirn;
505 	enum dma_transfer_direction dma_dirn;
506 	struct dma_async_tx_descriptor *desc;
507 	int ret;
508 
509 	peripheral = config->peripheral_config;
510 
511 	dma_buf = i2c_get_dma_safe_msg_buf(msg, 1);
512 	if (!dma_buf)
513 		return -ENOMEM;
514 
515 	if (op == I2C_WRITE)
516 		map_dirn = DMA_TO_DEVICE;
517 	else
518 		map_dirn = DMA_FROM_DEVICE;
519 
520 	addr = dma_map_single(gi2c->se.dev->parent, dma_buf, msg->len, map_dirn);
521 	if (dma_mapping_error(gi2c->se.dev->parent, addr)) {
522 		i2c_put_dma_safe_msg_buf(dma_buf, msg, false);
523 		return -ENOMEM;
524 	}
525 
526 	/* set the length as message for rx txn */
527 	peripheral->rx_len = msg->len;
528 	peripheral->op = op;
529 
530 	ret = dmaengine_slave_config(dma_chan, config);
531 	if (ret) {
532 		dev_err(gi2c->se.dev, "dma config error: %d for op:%d\n", ret, op);
533 		goto err_config;
534 	}
535 
536 	peripheral->set_config = 0;
537 	peripheral->multi_msg = true;
538 	flags = DMA_PREP_INTERRUPT | DMA_CTRL_ACK;
539 
540 	if (op == I2C_WRITE)
541 		dma_dirn = DMA_MEM_TO_DEV;
542 	else
543 		dma_dirn = DMA_DEV_TO_MEM;
544 
545 	desc = dmaengine_prep_slave_single(dma_chan, addr, msg->len, dma_dirn, flags);
546 	if (!desc) {
547 		dev_err(gi2c->se.dev, "prep_slave_sg failed\n");
548 		ret = -EIO;
549 		goto err_config;
550 	}
551 
552 	desc->callback_result = i2c_gpi_cb_result;
553 	desc->callback_param = gi2c;
554 
555 	dmaengine_submit(desc);
556 	*dma_addr_p = addr;
557 
558 	return 0;
559 
560 err_config:
561 	dma_unmap_single(gi2c->se.dev->parent, addr, msg->len, map_dirn);
562 	i2c_put_dma_safe_msg_buf(dma_buf, msg, false);
563 	return ret;
564 }
565 
566 static int geni_i2c_gpi_xfer(struct geni_i2c_dev *gi2c, struct i2c_msg msgs[], int num)
567 {
568 	struct dma_slave_config config = {};
569 	struct gpi_i2c_config peripheral = {};
570 	int i, ret = 0, timeout;
571 	dma_addr_t tx_addr, rx_addr;
572 	void *tx_buf = NULL, *rx_buf = NULL;
573 	const struct geni_i2c_clk_fld *itr = gi2c->clk_fld;
574 
575 	config.peripheral_config = &peripheral;
576 	config.peripheral_size = sizeof(peripheral);
577 
578 	peripheral.pack_enable = I2C_PACK_TX | I2C_PACK_RX;
579 	peripheral.cycle_count = itr->t_cycle_cnt;
580 	peripheral.high_count = itr->t_high_cnt;
581 	peripheral.low_count = itr->t_low_cnt;
582 	peripheral.clk_div = itr->clk_div;
583 	peripheral.set_config = 1;
584 	peripheral.multi_msg = false;
585 
586 	for (i = 0; i < num; i++) {
587 		gi2c->cur = &msgs[i];
588 		gi2c->err = 0;
589 		dev_dbg(gi2c->se.dev, "msg[%d].len:%d\n", i, gi2c->cur->len);
590 
591 		peripheral.stretch = 0;
592 		if (i < num - 1)
593 			peripheral.stretch = 1;
594 
595 		peripheral.addr = msgs[i].addr;
596 
597 		if (msgs[i].flags & I2C_M_RD) {
598 			ret =  geni_i2c_gpi(gi2c, &msgs[i], &config,
599 					    &rx_addr, &rx_buf, I2C_READ, gi2c->rx_c);
600 			if (ret)
601 				goto err;
602 		}
603 
604 		ret =  geni_i2c_gpi(gi2c, &msgs[i], &config,
605 				    &tx_addr, &tx_buf, I2C_WRITE, gi2c->tx_c);
606 		if (ret)
607 			goto err;
608 
609 		if (msgs[i].flags & I2C_M_RD)
610 			dma_async_issue_pending(gi2c->rx_c);
611 		dma_async_issue_pending(gi2c->tx_c);
612 
613 		timeout = wait_for_completion_timeout(&gi2c->done, XFER_TIMEOUT);
614 		if (!timeout) {
615 			dev_err(gi2c->se.dev, "I2C timeout gpi flags:%d addr:0x%x\n",
616 				gi2c->cur->flags, gi2c->cur->addr);
617 			gi2c->err = -ETIMEDOUT;
618 			goto err;
619 		}
620 
621 		if (gi2c->err) {
622 			ret = gi2c->err;
623 			goto err;
624 		}
625 
626 		geni_i2c_gpi_unmap(gi2c, &msgs[i], tx_buf, tx_addr, rx_buf, rx_addr);
627 	}
628 
629 	return num;
630 
631 err:
632 	dev_err(gi2c->se.dev, "GPI transfer failed: %d\n", ret);
633 	dmaengine_terminate_sync(gi2c->rx_c);
634 	dmaengine_terminate_sync(gi2c->tx_c);
635 	geni_i2c_gpi_unmap(gi2c, &msgs[i], tx_buf, tx_addr, rx_buf, rx_addr);
636 	return ret;
637 }
638 
639 static int geni_i2c_fifo_xfer(struct geni_i2c_dev *gi2c,
640 			      struct i2c_msg msgs[], int num)
641 {
642 	int i, ret = 0;
643 
644 	for (i = 0; i < num; i++) {
645 		u32 m_param = i < (num - 1) ? STOP_STRETCH : 0;
646 
647 		m_param |= ((msgs[i].addr << SLV_ADDR_SHFT) & SLV_ADDR_MSK);
648 
649 		gi2c->cur = &msgs[i];
650 		if (msgs[i].flags & I2C_M_RD)
651 			ret = geni_i2c_rx_one_msg(gi2c, &msgs[i], m_param);
652 		else
653 			ret = geni_i2c_tx_one_msg(gi2c, &msgs[i], m_param);
654 
655 		if (ret)
656 			return ret;
657 	}
658 
659 	return num;
660 }
661 
662 static int geni_i2c_xfer(struct i2c_adapter *adap,
663 			 struct i2c_msg msgs[],
664 			 int num)
665 {
666 	struct geni_i2c_dev *gi2c = i2c_get_adapdata(adap);
667 	int ret;
668 
669 	gi2c->err = 0;
670 	reinit_completion(&gi2c->done);
671 	ret = pm_runtime_get_sync(gi2c->se.dev);
672 	if (ret < 0) {
673 		dev_err(gi2c->se.dev, "error turning SE resources:%d\n", ret);
674 		pm_runtime_put_noidle(gi2c->se.dev);
675 		/* Set device in suspended since resume failed */
676 		pm_runtime_set_suspended(gi2c->se.dev);
677 		return ret;
678 	}
679 
680 	qcom_geni_i2c_conf(gi2c);
681 
682 	if (gi2c->gpi_mode)
683 		ret = geni_i2c_gpi_xfer(gi2c, msgs, num);
684 	else
685 		ret = geni_i2c_fifo_xfer(gi2c, msgs, num);
686 
687 	pm_runtime_mark_last_busy(gi2c->se.dev);
688 	pm_runtime_put_autosuspend(gi2c->se.dev);
689 	gi2c->cur = NULL;
690 	gi2c->err = 0;
691 	return num;
692 }
693 
694 static u32 geni_i2c_func(struct i2c_adapter *adap)
695 {
696 	return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
697 }
698 
699 static const struct i2c_algorithm geni_i2c_algo = {
700 	.master_xfer	= geni_i2c_xfer,
701 	.functionality	= geni_i2c_func,
702 };
703 
704 #ifdef CONFIG_ACPI
705 static const struct acpi_device_id geni_i2c_acpi_match[] = {
706 	{ "QCOM0220"},
707 	{ },
708 };
709 MODULE_DEVICE_TABLE(acpi, geni_i2c_acpi_match);
710 #endif
711 
712 static void release_gpi_dma(struct geni_i2c_dev *gi2c)
713 {
714 	if (gi2c->rx_c)
715 		dma_release_channel(gi2c->rx_c);
716 
717 	if (gi2c->tx_c)
718 		dma_release_channel(gi2c->tx_c);
719 }
720 
721 static int setup_gpi_dma(struct geni_i2c_dev *gi2c)
722 {
723 	int ret;
724 
725 	geni_se_select_mode(&gi2c->se, GENI_GPI_DMA);
726 	gi2c->tx_c = dma_request_chan(gi2c->se.dev, "tx");
727 	if (IS_ERR(gi2c->tx_c)) {
728 		ret = dev_err_probe(gi2c->se.dev, PTR_ERR(gi2c->tx_c),
729 				    "Failed to get tx DMA ch\n");
730 		if (ret < 0)
731 			goto err_tx;
732 	}
733 
734 	gi2c->rx_c = dma_request_chan(gi2c->se.dev, "rx");
735 	if (IS_ERR(gi2c->rx_c)) {
736 		ret = dev_err_probe(gi2c->se.dev, PTR_ERR(gi2c->rx_c),
737 				    "Failed to get rx DMA ch\n");
738 		if (ret < 0)
739 			goto err_rx;
740 	}
741 
742 	dev_dbg(gi2c->se.dev, "Grabbed GPI dma channels\n");
743 	return 0;
744 
745 err_rx:
746 	dma_release_channel(gi2c->tx_c);
747 err_tx:
748 	return ret;
749 }
750 
751 static int geni_i2c_probe(struct platform_device *pdev)
752 {
753 	struct geni_i2c_dev *gi2c;
754 	struct resource *res;
755 	u32 proto, tx_depth, fifo_disable;
756 	int ret;
757 	struct device *dev = &pdev->dev;
758 
759 	gi2c = devm_kzalloc(dev, sizeof(*gi2c), GFP_KERNEL);
760 	if (!gi2c)
761 		return -ENOMEM;
762 
763 	gi2c->se.dev = dev;
764 	gi2c->se.wrapper = dev_get_drvdata(dev->parent);
765 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
766 	gi2c->se.base = devm_ioremap_resource(dev, res);
767 	if (IS_ERR(gi2c->se.base))
768 		return PTR_ERR(gi2c->se.base);
769 
770 	gi2c->se.clk = devm_clk_get(dev, "se");
771 	if (IS_ERR(gi2c->se.clk) && !has_acpi_companion(dev))
772 		return PTR_ERR(gi2c->se.clk);
773 
774 	ret = device_property_read_u32(dev, "clock-frequency",
775 				       &gi2c->clk_freq_out);
776 	if (ret) {
777 		dev_info(dev, "Bus frequency not specified, default to 100kHz.\n");
778 		gi2c->clk_freq_out = KHZ(100);
779 	}
780 
781 	if (has_acpi_companion(dev))
782 		ACPI_COMPANION_SET(&gi2c->adap.dev, ACPI_COMPANION(dev));
783 
784 	gi2c->irq = platform_get_irq(pdev, 0);
785 	if (gi2c->irq < 0)
786 		return gi2c->irq;
787 
788 	ret = geni_i2c_clk_map_idx(gi2c);
789 	if (ret) {
790 		dev_err(dev, "Invalid clk frequency %d Hz: %d\n",
791 			gi2c->clk_freq_out, ret);
792 		return ret;
793 	}
794 
795 	gi2c->adap.algo = &geni_i2c_algo;
796 	init_completion(&gi2c->done);
797 	spin_lock_init(&gi2c->lock);
798 	platform_set_drvdata(pdev, gi2c);
799 	ret = devm_request_irq(dev, gi2c->irq, geni_i2c_irq, 0,
800 			       dev_name(dev), gi2c);
801 	if (ret) {
802 		dev_err(dev, "Request_irq failed:%d: err:%d\n",
803 			gi2c->irq, ret);
804 		return ret;
805 	}
806 	/* Disable the interrupt so that the system can enter low-power mode */
807 	disable_irq(gi2c->irq);
808 	i2c_set_adapdata(&gi2c->adap, gi2c);
809 	gi2c->adap.dev.parent = dev;
810 	gi2c->adap.dev.of_node = dev->of_node;
811 	strlcpy(gi2c->adap.name, "Geni-I2C", sizeof(gi2c->adap.name));
812 
813 	ret = geni_icc_get(&gi2c->se, "qup-memory");
814 	if (ret)
815 		return ret;
816 	/*
817 	 * Set the bus quota for core and cpu to a reasonable value for
818 	 * register access.
819 	 * Set quota for DDR based on bus speed.
820 	 */
821 	gi2c->se.icc_paths[GENI_TO_CORE].avg_bw = GENI_DEFAULT_BW;
822 	gi2c->se.icc_paths[CPU_TO_GENI].avg_bw = GENI_DEFAULT_BW;
823 	gi2c->se.icc_paths[GENI_TO_DDR].avg_bw = Bps_to_icc(gi2c->clk_freq_out);
824 
825 	ret = geni_icc_set_bw(&gi2c->se);
826 	if (ret)
827 		return ret;
828 
829 	ret = geni_se_resources_on(&gi2c->se);
830 	if (ret) {
831 		dev_err(dev, "Error turning on resources %d\n", ret);
832 		return ret;
833 	}
834 	proto = geni_se_read_proto(&gi2c->se);
835 	if (proto != GENI_SE_I2C) {
836 		dev_err(dev, "Invalid proto %d\n", proto);
837 		geni_se_resources_off(&gi2c->se);
838 		return -ENXIO;
839 	}
840 
841 	fifo_disable = readl_relaxed(gi2c->se.base + GENI_IF_DISABLE_RO) & FIFO_IF_DISABLE;
842 	if (fifo_disable) {
843 		/* FIFO is disabled, so we can only use GPI DMA */
844 		gi2c->gpi_mode = true;
845 		ret = setup_gpi_dma(gi2c);
846 		if (ret) {
847 			dev_err(dev, "Failed to setup GPI DMA mode:%d ret\n", ret);
848 			return ret;
849 		}
850 
851 		dev_dbg(dev, "Using GPI DMA mode for I2C\n");
852 	} else {
853 		gi2c->gpi_mode = false;
854 		tx_depth = geni_se_get_tx_fifo_depth(&gi2c->se);
855 		gi2c->tx_wm = tx_depth - 1;
856 		geni_se_init(&gi2c->se, gi2c->tx_wm, tx_depth);
857 		geni_se_config_packing(&gi2c->se, BITS_PER_BYTE,
858 				       PACKING_BYTES_PW, true, true, true);
859 
860 		dev_dbg(dev, "i2c fifo/se-dma mode. fifo depth:%d\n", tx_depth);
861 	}
862 
863 	ret = geni_se_resources_off(&gi2c->se);
864 	if (ret) {
865 		dev_err(dev, "Error turning off resources %d\n", ret);
866 		goto err_dma;
867 	}
868 
869 	ret = geni_icc_disable(&gi2c->se);
870 	if (ret)
871 		goto err_dma;
872 
873 	gi2c->suspended = 1;
874 	pm_runtime_set_suspended(gi2c->se.dev);
875 	pm_runtime_set_autosuspend_delay(gi2c->se.dev, I2C_AUTO_SUSPEND_DELAY);
876 	pm_runtime_use_autosuspend(gi2c->se.dev);
877 	pm_runtime_enable(gi2c->se.dev);
878 
879 	ret = i2c_add_adapter(&gi2c->adap);
880 	if (ret) {
881 		dev_err(dev, "Error adding i2c adapter %d\n", ret);
882 		pm_runtime_disable(gi2c->se.dev);
883 		goto err_dma;
884 	}
885 
886 	dev_dbg(dev, "Geni-I2C adaptor successfully added\n");
887 
888 	return 0;
889 
890 err_dma:
891 	release_gpi_dma(gi2c);
892 	return ret;
893 }
894 
895 static int geni_i2c_remove(struct platform_device *pdev)
896 {
897 	struct geni_i2c_dev *gi2c = platform_get_drvdata(pdev);
898 
899 	i2c_del_adapter(&gi2c->adap);
900 	release_gpi_dma(gi2c);
901 	pm_runtime_disable(gi2c->se.dev);
902 	return 0;
903 }
904 
905 static void geni_i2c_shutdown(struct platform_device *pdev)
906 {
907 	struct geni_i2c_dev *gi2c = platform_get_drvdata(pdev);
908 
909 	/* Make client i2c transfers start failing */
910 	i2c_mark_adapter_suspended(&gi2c->adap);
911 }
912 
913 static int __maybe_unused geni_i2c_runtime_suspend(struct device *dev)
914 {
915 	int ret;
916 	struct geni_i2c_dev *gi2c = dev_get_drvdata(dev);
917 
918 	disable_irq(gi2c->irq);
919 	ret = geni_se_resources_off(&gi2c->se);
920 	if (ret) {
921 		enable_irq(gi2c->irq);
922 		return ret;
923 
924 	} else {
925 		gi2c->suspended = 1;
926 	}
927 
928 	return geni_icc_disable(&gi2c->se);
929 }
930 
931 static int __maybe_unused geni_i2c_runtime_resume(struct device *dev)
932 {
933 	int ret;
934 	struct geni_i2c_dev *gi2c = dev_get_drvdata(dev);
935 
936 	ret = geni_icc_enable(&gi2c->se);
937 	if (ret)
938 		return ret;
939 
940 	ret = geni_se_resources_on(&gi2c->se);
941 	if (ret)
942 		return ret;
943 
944 	enable_irq(gi2c->irq);
945 	gi2c->suspended = 0;
946 	return 0;
947 }
948 
949 static int __maybe_unused geni_i2c_suspend_noirq(struct device *dev)
950 {
951 	struct geni_i2c_dev *gi2c = dev_get_drvdata(dev);
952 
953 	i2c_mark_adapter_suspended(&gi2c->adap);
954 
955 	if (!gi2c->suspended) {
956 		geni_i2c_runtime_suspend(dev);
957 		pm_runtime_disable(dev);
958 		pm_runtime_set_suspended(dev);
959 		pm_runtime_enable(dev);
960 	}
961 	return 0;
962 }
963 
964 static int __maybe_unused geni_i2c_resume_noirq(struct device *dev)
965 {
966 	struct geni_i2c_dev *gi2c = dev_get_drvdata(dev);
967 
968 	i2c_mark_adapter_resumed(&gi2c->adap);
969 	return 0;
970 }
971 
972 static const struct dev_pm_ops geni_i2c_pm_ops = {
973 	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(geni_i2c_suspend_noirq, geni_i2c_resume_noirq)
974 	SET_RUNTIME_PM_OPS(geni_i2c_runtime_suspend, geni_i2c_runtime_resume,
975 									NULL)
976 };
977 
978 static const struct of_device_id geni_i2c_dt_match[] = {
979 	{ .compatible = "qcom,geni-i2c" },
980 	{}
981 };
982 MODULE_DEVICE_TABLE(of, geni_i2c_dt_match);
983 
984 static struct platform_driver geni_i2c_driver = {
985 	.probe  = geni_i2c_probe,
986 	.remove = geni_i2c_remove,
987 	.shutdown = geni_i2c_shutdown,
988 	.driver = {
989 		.name = "geni_i2c",
990 		.pm = &geni_i2c_pm_ops,
991 		.of_match_table = geni_i2c_dt_match,
992 		.acpi_match_table = ACPI_PTR(geni_i2c_acpi_match),
993 	},
994 };
995 
996 module_platform_driver(geni_i2c_driver);
997 
998 MODULE_DESCRIPTION("I2C Controller Driver for GENI based QUP cores");
999 MODULE_LICENSE("GPL v2");
1000