xref: /linux/drivers/i2c/busses/i2c-qcom-geni.c (revision 42b16d3ac371a2fac9b6f08fd75f23f34ba3955a)
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/soc/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 	struct clk *core_clk;
92 	u32 clk_freq_out;
93 	const struct geni_i2c_clk_fld *clk_fld;
94 	int suspended;
95 	void *dma_buf;
96 	size_t xfer_len;
97 	dma_addr_t dma_addr;
98 	struct dma_chan *tx_c;
99 	struct dma_chan *rx_c;
100 	bool gpi_mode;
101 	bool abort_done;
102 };
103 
104 struct geni_i2c_desc {
105 	bool has_core_clk;
106 	char *icc_ddr;
107 	bool no_dma_support;
108 	unsigned int tx_fifo_depth;
109 };
110 
111 struct geni_i2c_err_log {
112 	int err;
113 	const char *msg;
114 };
115 
116 static const struct geni_i2c_err_log gi2c_log[] = {
117 	[GP_IRQ0] = {-EIO, "Unknown I2C err GP_IRQ0"},
118 	[NACK] = {-ENXIO, "NACK: slv unresponsive, check its power/reset-ln"},
119 	[GP_IRQ2] = {-EIO, "Unknown I2C err GP IRQ2"},
120 	[BUS_PROTO] = {-EPROTO, "Bus proto err, noisy/unexpected start/stop"},
121 	[ARB_LOST] = {-EAGAIN, "Bus arbitration lost, clock line undriveable"},
122 	[GP_IRQ5] = {-EIO, "Unknown I2C err GP IRQ5"},
123 	[GENI_OVERRUN] = {-EIO, "Cmd overrun, check GENI cmd-state machine"},
124 	[GENI_ILLEGAL_CMD] = {-EIO, "Illegal cmd, check GENI cmd-state machine"},
125 	[GENI_ABORT_DONE] = {-ETIMEDOUT, "Abort after timeout successful"},
126 	[GENI_TIMEOUT] = {-ETIMEDOUT, "I2C TXN timed out"},
127 };
128 
129 struct geni_i2c_clk_fld {
130 	u32	clk_freq_out;
131 	u8	clk_div;
132 	u8	t_high_cnt;
133 	u8	t_low_cnt;
134 	u8	t_cycle_cnt;
135 };
136 
137 /*
138  * Hardware uses the underlying formula to calculate time periods of
139  * SCL clock cycle. Firmware uses some additional cycles excluded from the
140  * below formula and it is confirmed that the time periods are within
141  * specification limits.
142  *
143  * time of high period of SCL: t_high = (t_high_cnt * clk_div) / source_clock
144  * time of low period of SCL: t_low = (t_low_cnt * clk_div) / source_clock
145  * time of full period of SCL: t_cycle = (t_cycle_cnt * clk_div) / source_clock
146  * clk_freq_out = t / t_cycle
147  * source_clock = 19.2 MHz
148  */
149 static const struct geni_i2c_clk_fld geni_i2c_clk_map[] = {
150 	{KHZ(100), 7, 10, 11, 26},
151 	{KHZ(400), 2,  5, 12, 24},
152 	{KHZ(1000), 1, 3,  9, 18},
153 };
154 
geni_i2c_clk_map_idx(struct geni_i2c_dev * gi2c)155 static int geni_i2c_clk_map_idx(struct geni_i2c_dev *gi2c)
156 {
157 	int i;
158 	const struct geni_i2c_clk_fld *itr = geni_i2c_clk_map;
159 
160 	for (i = 0; i < ARRAY_SIZE(geni_i2c_clk_map); i++, itr++) {
161 		if (itr->clk_freq_out == gi2c->clk_freq_out) {
162 			gi2c->clk_fld = itr;
163 			return 0;
164 		}
165 	}
166 	return -EINVAL;
167 }
168 
qcom_geni_i2c_conf(struct geni_i2c_dev * gi2c)169 static void qcom_geni_i2c_conf(struct geni_i2c_dev *gi2c)
170 {
171 	const struct geni_i2c_clk_fld *itr = gi2c->clk_fld;
172 	u32 val;
173 
174 	writel_relaxed(0, gi2c->se.base + SE_GENI_CLK_SEL);
175 
176 	val = (itr->clk_div << CLK_DIV_SHFT) | SER_CLK_EN;
177 	writel_relaxed(val, gi2c->se.base + GENI_SER_M_CLK_CFG);
178 
179 	val = itr->t_high_cnt << HIGH_COUNTER_SHFT;
180 	val |= itr->t_low_cnt << LOW_COUNTER_SHFT;
181 	val |= itr->t_cycle_cnt;
182 	writel_relaxed(val, gi2c->se.base + SE_I2C_SCL_COUNTERS);
183 }
184 
geni_i2c_err_misc(struct geni_i2c_dev * gi2c)185 static void geni_i2c_err_misc(struct geni_i2c_dev *gi2c)
186 {
187 	u32 m_cmd = readl_relaxed(gi2c->se.base + SE_GENI_M_CMD0);
188 	u32 m_stat = readl_relaxed(gi2c->se.base + SE_GENI_M_IRQ_STATUS);
189 	u32 geni_s = readl_relaxed(gi2c->se.base + SE_GENI_STATUS);
190 	u32 geni_ios = readl_relaxed(gi2c->se.base + SE_GENI_IOS);
191 	u32 dma = readl_relaxed(gi2c->se.base + SE_GENI_DMA_MODE_EN);
192 	u32 rx_st, tx_st;
193 
194 	if (dma) {
195 		rx_st = readl_relaxed(gi2c->se.base + SE_DMA_RX_IRQ_STAT);
196 		tx_st = readl_relaxed(gi2c->se.base + SE_DMA_TX_IRQ_STAT);
197 	} else {
198 		rx_st = readl_relaxed(gi2c->se.base + SE_GENI_RX_FIFO_STATUS);
199 		tx_st = readl_relaxed(gi2c->se.base + SE_GENI_TX_FIFO_STATUS);
200 	}
201 	dev_dbg(gi2c->se.dev, "DMA:%d tx_stat:0x%x, rx_stat:0x%x, irq-stat:0x%x\n",
202 		dma, tx_st, rx_st, m_stat);
203 	dev_dbg(gi2c->se.dev, "m_cmd:0x%x, geni_status:0x%x, geni_ios:0x%x\n",
204 		m_cmd, geni_s, geni_ios);
205 }
206 
geni_i2c_err(struct geni_i2c_dev * gi2c,int err)207 static void geni_i2c_err(struct geni_i2c_dev *gi2c, int err)
208 {
209 	if (!gi2c->err)
210 		gi2c->err = gi2c_log[err].err;
211 	if (gi2c->cur)
212 		dev_dbg(gi2c->se.dev, "len:%d, slv-addr:0x%x, RD/WR:%d\n",
213 			gi2c->cur->len, gi2c->cur->addr, gi2c->cur->flags);
214 
215 	switch (err) {
216 	case GENI_ABORT_DONE:
217 		gi2c->abort_done = true;
218 		break;
219 	case NACK:
220 	case GENI_TIMEOUT:
221 		dev_dbg(gi2c->se.dev, "%s\n", gi2c_log[err].msg);
222 		break;
223 	default:
224 		dev_err(gi2c->se.dev, "%s\n", gi2c_log[err].msg);
225 		geni_i2c_err_misc(gi2c);
226 		break;
227 	}
228 }
229 
geni_i2c_irq(int irq,void * dev)230 static irqreturn_t geni_i2c_irq(int irq, void *dev)
231 {
232 	struct geni_i2c_dev *gi2c = dev;
233 	void __iomem *base = gi2c->se.base;
234 	int j, p;
235 	u32 m_stat;
236 	u32 rx_st;
237 	u32 dm_tx_st;
238 	u32 dm_rx_st;
239 	u32 dma;
240 	u32 val;
241 	struct i2c_msg *cur;
242 
243 	spin_lock(&gi2c->lock);
244 	m_stat = readl_relaxed(base + SE_GENI_M_IRQ_STATUS);
245 	rx_st = readl_relaxed(base + SE_GENI_RX_FIFO_STATUS);
246 	dm_tx_st = readl_relaxed(base + SE_DMA_TX_IRQ_STAT);
247 	dm_rx_st = readl_relaxed(base + SE_DMA_RX_IRQ_STAT);
248 	dma = readl_relaxed(base + SE_GENI_DMA_MODE_EN);
249 	cur = gi2c->cur;
250 
251 	if (!cur ||
252 	    m_stat & (M_CMD_FAILURE_EN | M_CMD_ABORT_EN) ||
253 	    dm_rx_st & (DM_I2C_CB_ERR)) {
254 		if (m_stat & M_GP_IRQ_1_EN)
255 			geni_i2c_err(gi2c, NACK);
256 		if (m_stat & M_GP_IRQ_3_EN)
257 			geni_i2c_err(gi2c, BUS_PROTO);
258 		if (m_stat & M_GP_IRQ_4_EN)
259 			geni_i2c_err(gi2c, ARB_LOST);
260 		if (m_stat & M_CMD_OVERRUN_EN)
261 			geni_i2c_err(gi2c, GENI_OVERRUN);
262 		if (m_stat & M_ILLEGAL_CMD_EN)
263 			geni_i2c_err(gi2c, GENI_ILLEGAL_CMD);
264 		if (m_stat & M_CMD_ABORT_EN)
265 			geni_i2c_err(gi2c, GENI_ABORT_DONE);
266 		if (m_stat & M_GP_IRQ_0_EN)
267 			geni_i2c_err(gi2c, GP_IRQ0);
268 
269 		/* Disable the TX Watermark interrupt to stop TX */
270 		if (!dma)
271 			writel_relaxed(0, base + SE_GENI_TX_WATERMARK_REG);
272 	} else if (dma) {
273 		dev_dbg(gi2c->se.dev, "i2c dma tx:0x%x, dma rx:0x%x\n",
274 			dm_tx_st, dm_rx_st);
275 	} else if (cur->flags & I2C_M_RD &&
276 		   m_stat & (M_RX_FIFO_WATERMARK_EN | M_RX_FIFO_LAST_EN)) {
277 		u32 rxcnt = rx_st & RX_FIFO_WC_MSK;
278 
279 		for (j = 0; j < rxcnt; j++) {
280 			p = 0;
281 			val = readl_relaxed(base + SE_GENI_RX_FIFOn);
282 			while (gi2c->cur_rd < cur->len && p < sizeof(val)) {
283 				cur->buf[gi2c->cur_rd++] = val & 0xff;
284 				val >>= 8;
285 				p++;
286 			}
287 			if (gi2c->cur_rd == cur->len)
288 				break;
289 		}
290 	} else if (!(cur->flags & I2C_M_RD) &&
291 		   m_stat & M_TX_FIFO_WATERMARK_EN) {
292 		for (j = 0; j < gi2c->tx_wm; j++) {
293 			u32 temp;
294 
295 			val = 0;
296 			p = 0;
297 			while (gi2c->cur_wr < cur->len && p < sizeof(val)) {
298 				temp = cur->buf[gi2c->cur_wr++];
299 				val |= temp << (p * 8);
300 				p++;
301 			}
302 			writel_relaxed(val, base + SE_GENI_TX_FIFOn);
303 			/* TX Complete, Disable the TX Watermark interrupt */
304 			if (gi2c->cur_wr == cur->len) {
305 				writel_relaxed(0, base + SE_GENI_TX_WATERMARK_REG);
306 				break;
307 			}
308 		}
309 	}
310 
311 	if (m_stat)
312 		writel_relaxed(m_stat, base + SE_GENI_M_IRQ_CLEAR);
313 
314 	if (dma && dm_tx_st)
315 		writel_relaxed(dm_tx_st, base + SE_DMA_TX_IRQ_CLR);
316 	if (dma && dm_rx_st)
317 		writel_relaxed(dm_rx_st, base + SE_DMA_RX_IRQ_CLR);
318 
319 	/* if this is err with done-bit not set, handle that through timeout. */
320 	if (m_stat & M_CMD_DONE_EN || m_stat & M_CMD_ABORT_EN ||
321 	    dm_tx_st & TX_DMA_DONE || dm_tx_st & TX_RESET_DONE ||
322 	    dm_rx_st & RX_DMA_DONE || dm_rx_st & RX_RESET_DONE)
323 		complete(&gi2c->done);
324 
325 	spin_unlock(&gi2c->lock);
326 
327 	return IRQ_HANDLED;
328 }
329 
geni_i2c_abort_xfer(struct geni_i2c_dev * gi2c)330 static void geni_i2c_abort_xfer(struct geni_i2c_dev *gi2c)
331 {
332 	unsigned long time_left = ABORT_TIMEOUT;
333 	unsigned long flags;
334 
335 	spin_lock_irqsave(&gi2c->lock, flags);
336 	geni_i2c_err(gi2c, GENI_TIMEOUT);
337 	gi2c->cur = NULL;
338 	gi2c->abort_done = false;
339 	geni_se_abort_m_cmd(&gi2c->se);
340 	spin_unlock_irqrestore(&gi2c->lock, flags);
341 
342 	do {
343 		time_left = wait_for_completion_timeout(&gi2c->done, time_left);
344 	} while (!gi2c->abort_done && time_left);
345 
346 	if (!time_left)
347 		dev_err(gi2c->se.dev, "Timeout abort_m_cmd\n");
348 }
349 
geni_i2c_rx_fsm_rst(struct geni_i2c_dev * gi2c)350 static void geni_i2c_rx_fsm_rst(struct geni_i2c_dev *gi2c)
351 {
352 	u32 val;
353 	unsigned long time_left = RST_TIMEOUT;
354 
355 	writel_relaxed(1, gi2c->se.base + SE_DMA_RX_FSM_RST);
356 	do {
357 		time_left = wait_for_completion_timeout(&gi2c->done, time_left);
358 		val = readl_relaxed(gi2c->se.base + SE_DMA_RX_IRQ_STAT);
359 	} while (!(val & RX_RESET_DONE) && time_left);
360 
361 	if (!(val & RX_RESET_DONE))
362 		dev_err(gi2c->se.dev, "Timeout resetting RX_FSM\n");
363 }
364 
geni_i2c_tx_fsm_rst(struct geni_i2c_dev * gi2c)365 static void geni_i2c_tx_fsm_rst(struct geni_i2c_dev *gi2c)
366 {
367 	u32 val;
368 	unsigned long time_left = RST_TIMEOUT;
369 
370 	writel_relaxed(1, gi2c->se.base + SE_DMA_TX_FSM_RST);
371 	do {
372 		time_left = wait_for_completion_timeout(&gi2c->done, time_left);
373 		val = readl_relaxed(gi2c->se.base + SE_DMA_TX_IRQ_STAT);
374 	} while (!(val & TX_RESET_DONE) && time_left);
375 
376 	if (!(val & TX_RESET_DONE))
377 		dev_err(gi2c->se.dev, "Timeout resetting TX_FSM\n");
378 }
379 
geni_i2c_rx_msg_cleanup(struct geni_i2c_dev * gi2c,struct i2c_msg * cur)380 static void geni_i2c_rx_msg_cleanup(struct geni_i2c_dev *gi2c,
381 				     struct i2c_msg *cur)
382 {
383 	gi2c->cur_rd = 0;
384 	if (gi2c->dma_buf) {
385 		if (gi2c->err)
386 			geni_i2c_rx_fsm_rst(gi2c);
387 		geni_se_rx_dma_unprep(&gi2c->se, gi2c->dma_addr, gi2c->xfer_len);
388 		i2c_put_dma_safe_msg_buf(gi2c->dma_buf, cur, !gi2c->err);
389 	}
390 }
391 
geni_i2c_tx_msg_cleanup(struct geni_i2c_dev * gi2c,struct i2c_msg * cur)392 static void geni_i2c_tx_msg_cleanup(struct geni_i2c_dev *gi2c,
393 				     struct i2c_msg *cur)
394 {
395 	gi2c->cur_wr = 0;
396 	if (gi2c->dma_buf) {
397 		if (gi2c->err)
398 			geni_i2c_tx_fsm_rst(gi2c);
399 		geni_se_tx_dma_unprep(&gi2c->se, gi2c->dma_addr, gi2c->xfer_len);
400 		i2c_put_dma_safe_msg_buf(gi2c->dma_buf, cur, !gi2c->err);
401 	}
402 }
403 
geni_i2c_rx_one_msg(struct geni_i2c_dev * gi2c,struct i2c_msg * msg,u32 m_param)404 static int geni_i2c_rx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
405 				u32 m_param)
406 {
407 	dma_addr_t rx_dma = 0;
408 	unsigned long time_left;
409 	void *dma_buf;
410 	struct geni_se *se = &gi2c->se;
411 	size_t len = msg->len;
412 	struct i2c_msg *cur;
413 
414 	dma_buf = i2c_get_dma_safe_msg_buf(msg, 32);
415 	if (dma_buf)
416 		geni_se_select_mode(se, GENI_SE_DMA);
417 	else
418 		geni_se_select_mode(se, GENI_SE_FIFO);
419 
420 	writel_relaxed(len, se->base + SE_I2C_RX_TRANS_LEN);
421 	geni_se_setup_m_cmd(se, I2C_READ, m_param);
422 
423 	if (dma_buf && geni_se_rx_dma_prep(se, dma_buf, len, &rx_dma)) {
424 		geni_se_select_mode(se, GENI_SE_FIFO);
425 		i2c_put_dma_safe_msg_buf(dma_buf, msg, false);
426 		dma_buf = NULL;
427 	} else {
428 		gi2c->xfer_len = len;
429 		gi2c->dma_addr = rx_dma;
430 		gi2c->dma_buf = dma_buf;
431 	}
432 
433 	cur = gi2c->cur;
434 	time_left = wait_for_completion_timeout(&gi2c->done, XFER_TIMEOUT);
435 	if (!time_left)
436 		geni_i2c_abort_xfer(gi2c);
437 
438 	geni_i2c_rx_msg_cleanup(gi2c, cur);
439 
440 	return gi2c->err;
441 }
442 
geni_i2c_tx_one_msg(struct geni_i2c_dev * gi2c,struct i2c_msg * msg,u32 m_param)443 static int geni_i2c_tx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
444 				u32 m_param)
445 {
446 	dma_addr_t tx_dma = 0;
447 	unsigned long time_left;
448 	void *dma_buf;
449 	struct geni_se *se = &gi2c->se;
450 	size_t len = msg->len;
451 	struct i2c_msg *cur;
452 
453 	dma_buf = i2c_get_dma_safe_msg_buf(msg, 32);
454 	if (dma_buf)
455 		geni_se_select_mode(se, GENI_SE_DMA);
456 	else
457 		geni_se_select_mode(se, GENI_SE_FIFO);
458 
459 	writel_relaxed(len, se->base + SE_I2C_TX_TRANS_LEN);
460 	geni_se_setup_m_cmd(se, I2C_WRITE, m_param);
461 
462 	if (dma_buf && geni_se_tx_dma_prep(se, dma_buf, len, &tx_dma)) {
463 		geni_se_select_mode(se, GENI_SE_FIFO);
464 		i2c_put_dma_safe_msg_buf(dma_buf, msg, false);
465 		dma_buf = NULL;
466 	} else {
467 		gi2c->xfer_len = len;
468 		gi2c->dma_addr = tx_dma;
469 		gi2c->dma_buf = dma_buf;
470 	}
471 
472 	if (!dma_buf) /* Get FIFO IRQ */
473 		writel_relaxed(1, se->base + SE_GENI_TX_WATERMARK_REG);
474 
475 	cur = gi2c->cur;
476 	time_left = wait_for_completion_timeout(&gi2c->done, XFER_TIMEOUT);
477 	if (!time_left)
478 		geni_i2c_abort_xfer(gi2c);
479 
480 	geni_i2c_tx_msg_cleanup(gi2c, cur);
481 
482 	return gi2c->err;
483 }
484 
i2c_gpi_cb_result(void * cb,const struct dmaengine_result * result)485 static void i2c_gpi_cb_result(void *cb, const struct dmaengine_result *result)
486 {
487 	struct geni_i2c_dev *gi2c = cb;
488 
489 	if (result->result != DMA_TRANS_NOERROR) {
490 		dev_err(gi2c->se.dev, "DMA txn failed:%d\n", result->result);
491 		gi2c->err = -EIO;
492 	} else if (result->residue) {
493 		dev_dbg(gi2c->se.dev, "DMA xfer has pending: %d\n", result->residue);
494 	}
495 
496 	complete(&gi2c->done);
497 }
498 
geni_i2c_gpi_unmap(struct geni_i2c_dev * gi2c,struct i2c_msg * msg,void * tx_buf,dma_addr_t tx_addr,void * rx_buf,dma_addr_t rx_addr)499 static void geni_i2c_gpi_unmap(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
500 			       void *tx_buf, dma_addr_t tx_addr,
501 			       void *rx_buf, dma_addr_t rx_addr)
502 {
503 	if (tx_buf) {
504 		dma_unmap_single(gi2c->se.dev->parent, tx_addr, msg->len, DMA_TO_DEVICE);
505 		i2c_put_dma_safe_msg_buf(tx_buf, msg, !gi2c->err);
506 	}
507 
508 	if (rx_buf) {
509 		dma_unmap_single(gi2c->se.dev->parent, rx_addr, msg->len, DMA_FROM_DEVICE);
510 		i2c_put_dma_safe_msg_buf(rx_buf, msg, !gi2c->err);
511 	}
512 }
513 
geni_i2c_gpi(struct geni_i2c_dev * gi2c,struct i2c_msg * msg,struct dma_slave_config * config,dma_addr_t * dma_addr_p,void ** buf,unsigned int op,struct dma_chan * dma_chan)514 static int geni_i2c_gpi(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
515 			struct dma_slave_config *config, dma_addr_t *dma_addr_p,
516 			void **buf, unsigned int op, struct dma_chan *dma_chan)
517 {
518 	struct gpi_i2c_config *peripheral;
519 	unsigned int flags;
520 	void *dma_buf;
521 	dma_addr_t addr;
522 	enum dma_data_direction map_dirn;
523 	enum dma_transfer_direction dma_dirn;
524 	struct dma_async_tx_descriptor *desc;
525 	int ret;
526 
527 	peripheral = config->peripheral_config;
528 
529 	dma_buf = i2c_get_dma_safe_msg_buf(msg, 1);
530 	if (!dma_buf)
531 		return -ENOMEM;
532 
533 	if (op == I2C_WRITE)
534 		map_dirn = DMA_TO_DEVICE;
535 	else
536 		map_dirn = DMA_FROM_DEVICE;
537 
538 	addr = dma_map_single(gi2c->se.dev->parent, dma_buf, msg->len, map_dirn);
539 	if (dma_mapping_error(gi2c->se.dev->parent, addr)) {
540 		i2c_put_dma_safe_msg_buf(dma_buf, msg, false);
541 		return -ENOMEM;
542 	}
543 
544 	/* set the length as message for rx txn */
545 	peripheral->rx_len = msg->len;
546 	peripheral->op = op;
547 
548 	ret = dmaengine_slave_config(dma_chan, config);
549 	if (ret) {
550 		dev_err(gi2c->se.dev, "dma config error: %d for op:%d\n", ret, op);
551 		goto err_config;
552 	}
553 
554 	peripheral->set_config = 0;
555 	peripheral->multi_msg = true;
556 	flags = DMA_PREP_INTERRUPT | DMA_CTRL_ACK;
557 
558 	if (op == I2C_WRITE)
559 		dma_dirn = DMA_MEM_TO_DEV;
560 	else
561 		dma_dirn = DMA_DEV_TO_MEM;
562 
563 	desc = dmaengine_prep_slave_single(dma_chan, addr, msg->len, dma_dirn, flags);
564 	if (!desc) {
565 		dev_err(gi2c->se.dev, "prep_slave_sg failed\n");
566 		ret = -EIO;
567 		goto err_config;
568 	}
569 
570 	desc->callback_result = i2c_gpi_cb_result;
571 	desc->callback_param = gi2c;
572 
573 	dmaengine_submit(desc);
574 	*buf = dma_buf;
575 	*dma_addr_p = addr;
576 
577 	return 0;
578 
579 err_config:
580 	dma_unmap_single(gi2c->se.dev->parent, addr, msg->len, map_dirn);
581 	i2c_put_dma_safe_msg_buf(dma_buf, msg, false);
582 	return ret;
583 }
584 
geni_i2c_gpi_xfer(struct geni_i2c_dev * gi2c,struct i2c_msg msgs[],int num)585 static int geni_i2c_gpi_xfer(struct geni_i2c_dev *gi2c, struct i2c_msg msgs[], int num)
586 {
587 	struct dma_slave_config config = {};
588 	struct gpi_i2c_config peripheral = {};
589 	int i, ret = 0;
590 	unsigned long time_left;
591 	dma_addr_t tx_addr, rx_addr;
592 	void *tx_buf = NULL, *rx_buf = NULL;
593 	const struct geni_i2c_clk_fld *itr = gi2c->clk_fld;
594 
595 	config.peripheral_config = &peripheral;
596 	config.peripheral_size = sizeof(peripheral);
597 
598 	peripheral.pack_enable = I2C_PACK_TX | I2C_PACK_RX;
599 	peripheral.cycle_count = itr->t_cycle_cnt;
600 	peripheral.high_count = itr->t_high_cnt;
601 	peripheral.low_count = itr->t_low_cnt;
602 	peripheral.clk_div = itr->clk_div;
603 	peripheral.set_config = 1;
604 	peripheral.multi_msg = false;
605 
606 	for (i = 0; i < num; i++) {
607 		gi2c->cur = &msgs[i];
608 		gi2c->err = 0;
609 		dev_dbg(gi2c->se.dev, "msg[%d].len:%d\n", i, gi2c->cur->len);
610 
611 		peripheral.stretch = 0;
612 		if (i < num - 1)
613 			peripheral.stretch = 1;
614 
615 		peripheral.addr = msgs[i].addr;
616 
617 		ret =  geni_i2c_gpi(gi2c, &msgs[i], &config,
618 				    &tx_addr, &tx_buf, I2C_WRITE, gi2c->tx_c);
619 		if (ret)
620 			goto err;
621 
622 		if (msgs[i].flags & I2C_M_RD) {
623 			ret =  geni_i2c_gpi(gi2c, &msgs[i], &config,
624 					    &rx_addr, &rx_buf, I2C_READ, gi2c->rx_c);
625 			if (ret)
626 				goto err;
627 
628 			dma_async_issue_pending(gi2c->rx_c);
629 		}
630 
631 		dma_async_issue_pending(gi2c->tx_c);
632 
633 		time_left = wait_for_completion_timeout(&gi2c->done, XFER_TIMEOUT);
634 		if (!time_left)
635 			gi2c->err = -ETIMEDOUT;
636 
637 		if (gi2c->err) {
638 			ret = gi2c->err;
639 			goto err;
640 		}
641 
642 		geni_i2c_gpi_unmap(gi2c, &msgs[i], tx_buf, tx_addr, rx_buf, rx_addr);
643 	}
644 
645 	return num;
646 
647 err:
648 	dev_err(gi2c->se.dev, "GPI transfer failed: %d\n", ret);
649 	dmaengine_terminate_sync(gi2c->rx_c);
650 	dmaengine_terminate_sync(gi2c->tx_c);
651 	geni_i2c_gpi_unmap(gi2c, &msgs[i], tx_buf, tx_addr, rx_buf, rx_addr);
652 	return ret;
653 }
654 
geni_i2c_fifo_xfer(struct geni_i2c_dev * gi2c,struct i2c_msg msgs[],int num)655 static int geni_i2c_fifo_xfer(struct geni_i2c_dev *gi2c,
656 			      struct i2c_msg msgs[], int num)
657 {
658 	int i, ret = 0;
659 
660 	for (i = 0; i < num; i++) {
661 		u32 m_param = i < (num - 1) ? STOP_STRETCH : 0;
662 
663 		m_param |= ((msgs[i].addr << SLV_ADDR_SHFT) & SLV_ADDR_MSK);
664 
665 		gi2c->cur = &msgs[i];
666 		if (msgs[i].flags & I2C_M_RD)
667 			ret = geni_i2c_rx_one_msg(gi2c, &msgs[i], m_param);
668 		else
669 			ret = geni_i2c_tx_one_msg(gi2c, &msgs[i], m_param);
670 
671 		if (ret)
672 			return ret;
673 	}
674 
675 	return num;
676 }
677 
geni_i2c_xfer(struct i2c_adapter * adap,struct i2c_msg msgs[],int num)678 static int geni_i2c_xfer(struct i2c_adapter *adap,
679 			 struct i2c_msg msgs[],
680 			 int num)
681 {
682 	struct geni_i2c_dev *gi2c = i2c_get_adapdata(adap);
683 	int ret;
684 
685 	gi2c->err = 0;
686 	reinit_completion(&gi2c->done);
687 	ret = pm_runtime_get_sync(gi2c->se.dev);
688 	if (ret < 0) {
689 		dev_err(gi2c->se.dev, "error turning SE resources:%d\n", ret);
690 		pm_runtime_put_noidle(gi2c->se.dev);
691 		/* Set device in suspended since resume failed */
692 		pm_runtime_set_suspended(gi2c->se.dev);
693 		return ret;
694 	}
695 
696 	qcom_geni_i2c_conf(gi2c);
697 
698 	if (gi2c->gpi_mode)
699 		ret = geni_i2c_gpi_xfer(gi2c, msgs, num);
700 	else
701 		ret = geni_i2c_fifo_xfer(gi2c, msgs, num);
702 
703 	pm_runtime_mark_last_busy(gi2c->se.dev);
704 	pm_runtime_put_autosuspend(gi2c->se.dev);
705 	gi2c->cur = NULL;
706 	gi2c->err = 0;
707 	return ret;
708 }
709 
geni_i2c_func(struct i2c_adapter * adap)710 static u32 geni_i2c_func(struct i2c_adapter *adap)
711 {
712 	return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
713 }
714 
715 static const struct i2c_algorithm geni_i2c_algo = {
716 	.master_xfer	= geni_i2c_xfer,
717 	.functionality	= geni_i2c_func,
718 };
719 
720 #ifdef CONFIG_ACPI
721 static const struct acpi_device_id geni_i2c_acpi_match[] = {
722 	{ "QCOM0220"},
723 	{ "QCOM0411" },
724 	{ }
725 };
726 MODULE_DEVICE_TABLE(acpi, geni_i2c_acpi_match);
727 #endif
728 
release_gpi_dma(struct geni_i2c_dev * gi2c)729 static void release_gpi_dma(struct geni_i2c_dev *gi2c)
730 {
731 	if (gi2c->rx_c)
732 		dma_release_channel(gi2c->rx_c);
733 
734 	if (gi2c->tx_c)
735 		dma_release_channel(gi2c->tx_c);
736 }
737 
setup_gpi_dma(struct geni_i2c_dev * gi2c)738 static int setup_gpi_dma(struct geni_i2c_dev *gi2c)
739 {
740 	int ret;
741 
742 	geni_se_select_mode(&gi2c->se, GENI_GPI_DMA);
743 	gi2c->tx_c = dma_request_chan(gi2c->se.dev, "tx");
744 	if (IS_ERR(gi2c->tx_c)) {
745 		ret = dev_err_probe(gi2c->se.dev, PTR_ERR(gi2c->tx_c),
746 				    "Failed to get tx DMA ch\n");
747 		goto err_tx;
748 	}
749 
750 	gi2c->rx_c = dma_request_chan(gi2c->se.dev, "rx");
751 	if (IS_ERR(gi2c->rx_c)) {
752 		ret = dev_err_probe(gi2c->se.dev, PTR_ERR(gi2c->rx_c),
753 				    "Failed to get rx DMA ch\n");
754 		goto err_rx;
755 	}
756 
757 	dev_dbg(gi2c->se.dev, "Grabbed GPI dma channels\n");
758 	return 0;
759 
760 err_rx:
761 	dma_release_channel(gi2c->tx_c);
762 err_tx:
763 	return ret;
764 }
765 
geni_i2c_probe(struct platform_device * pdev)766 static int geni_i2c_probe(struct platform_device *pdev)
767 {
768 	struct geni_i2c_dev *gi2c;
769 	u32 proto, tx_depth, fifo_disable;
770 	int ret;
771 	struct device *dev = &pdev->dev;
772 	const struct geni_i2c_desc *desc = NULL;
773 
774 	gi2c = devm_kzalloc(dev, sizeof(*gi2c), GFP_KERNEL);
775 	if (!gi2c)
776 		return -ENOMEM;
777 
778 	gi2c->se.dev = dev;
779 	gi2c->se.wrapper = dev_get_drvdata(dev->parent);
780 	gi2c->se.base = devm_platform_ioremap_resource(pdev, 0);
781 	if (IS_ERR(gi2c->se.base))
782 		return PTR_ERR(gi2c->se.base);
783 
784 	desc = device_get_match_data(&pdev->dev);
785 
786 	if (desc && desc->has_core_clk) {
787 		gi2c->core_clk = devm_clk_get(dev, "core");
788 		if (IS_ERR(gi2c->core_clk))
789 			return PTR_ERR(gi2c->core_clk);
790 	}
791 
792 	gi2c->se.clk = devm_clk_get(dev, "se");
793 	if (IS_ERR(gi2c->se.clk) && !has_acpi_companion(dev))
794 		return PTR_ERR(gi2c->se.clk);
795 
796 	ret = device_property_read_u32(dev, "clock-frequency",
797 				       &gi2c->clk_freq_out);
798 	if (ret) {
799 		dev_info(dev, "Bus frequency not specified, default to 100kHz.\n");
800 		gi2c->clk_freq_out = KHZ(100);
801 	}
802 
803 	if (has_acpi_companion(dev))
804 		ACPI_COMPANION_SET(&gi2c->adap.dev, ACPI_COMPANION(dev));
805 
806 	gi2c->irq = platform_get_irq(pdev, 0);
807 	if (gi2c->irq < 0)
808 		return gi2c->irq;
809 
810 	ret = geni_i2c_clk_map_idx(gi2c);
811 	if (ret) {
812 		dev_err(dev, "Invalid clk frequency %d Hz: %d\n",
813 			gi2c->clk_freq_out, ret);
814 		return ret;
815 	}
816 
817 	gi2c->adap.algo = &geni_i2c_algo;
818 	init_completion(&gi2c->done);
819 	spin_lock_init(&gi2c->lock);
820 	platform_set_drvdata(pdev, gi2c);
821 	ret = devm_request_irq(dev, gi2c->irq, geni_i2c_irq, IRQF_NO_AUTOEN,
822 			       dev_name(dev), gi2c);
823 	if (ret) {
824 		dev_err(dev, "Request_irq failed:%d: err:%d\n",
825 			gi2c->irq, ret);
826 		return ret;
827 	}
828 	i2c_set_adapdata(&gi2c->adap, gi2c);
829 	gi2c->adap.dev.parent = dev;
830 	gi2c->adap.dev.of_node = dev->of_node;
831 	strscpy(gi2c->adap.name, "Geni-I2C", sizeof(gi2c->adap.name));
832 
833 	ret = geni_icc_get(&gi2c->se, desc ? desc->icc_ddr : "qup-memory");
834 	if (ret)
835 		return ret;
836 	/*
837 	 * Set the bus quota for core and cpu to a reasonable value for
838 	 * register access.
839 	 * Set quota for DDR based on bus speed.
840 	 */
841 	gi2c->se.icc_paths[GENI_TO_CORE].avg_bw = GENI_DEFAULT_BW;
842 	gi2c->se.icc_paths[CPU_TO_GENI].avg_bw = GENI_DEFAULT_BW;
843 	if (!desc || desc->icc_ddr)
844 		gi2c->se.icc_paths[GENI_TO_DDR].avg_bw = Bps_to_icc(gi2c->clk_freq_out);
845 
846 	ret = geni_icc_set_bw(&gi2c->se);
847 	if (ret)
848 		return ret;
849 
850 	ret = clk_prepare_enable(gi2c->core_clk);
851 	if (ret)
852 		return ret;
853 
854 	ret = geni_se_resources_on(&gi2c->se);
855 	if (ret) {
856 		dev_err(dev, "Error turning on resources %d\n", ret);
857 		clk_disable_unprepare(gi2c->core_clk);
858 		return ret;
859 	}
860 	proto = geni_se_read_proto(&gi2c->se);
861 	if (proto != GENI_SE_I2C) {
862 		dev_err(dev, "Invalid proto %d\n", proto);
863 		geni_se_resources_off(&gi2c->se);
864 		clk_disable_unprepare(gi2c->core_clk);
865 		return -ENXIO;
866 	}
867 
868 	if (desc && desc->no_dma_support)
869 		fifo_disable = false;
870 	else
871 		fifo_disable = readl_relaxed(gi2c->se.base + GENI_IF_DISABLE_RO) & FIFO_IF_DISABLE;
872 
873 	if (fifo_disable) {
874 		/* FIFO is disabled, so we can only use GPI DMA */
875 		gi2c->gpi_mode = true;
876 		ret = setup_gpi_dma(gi2c);
877 		if (ret) {
878 			geni_se_resources_off(&gi2c->se);
879 			clk_disable_unprepare(gi2c->core_clk);
880 			return dev_err_probe(dev, ret, "Failed to setup GPI DMA mode\n");
881 		}
882 
883 		dev_dbg(dev, "Using GPI DMA mode for I2C\n");
884 	} else {
885 		gi2c->gpi_mode = false;
886 		tx_depth = geni_se_get_tx_fifo_depth(&gi2c->se);
887 
888 		/* I2C Master Hub Serial Elements doesn't have the HW_PARAM_0 register */
889 		if (!tx_depth && desc)
890 			tx_depth = desc->tx_fifo_depth;
891 
892 		if (!tx_depth) {
893 			dev_err(dev, "Invalid TX FIFO depth\n");
894 			geni_se_resources_off(&gi2c->se);
895 			clk_disable_unprepare(gi2c->core_clk);
896 			return -EINVAL;
897 		}
898 
899 		gi2c->tx_wm = tx_depth - 1;
900 		geni_se_init(&gi2c->se, gi2c->tx_wm, tx_depth);
901 		geni_se_config_packing(&gi2c->se, BITS_PER_BYTE,
902 				       PACKING_BYTES_PW, true, true, true);
903 
904 		dev_dbg(dev, "i2c fifo/se-dma mode. fifo depth:%d\n", tx_depth);
905 	}
906 
907 	clk_disable_unprepare(gi2c->core_clk);
908 	ret = geni_se_resources_off(&gi2c->se);
909 	if (ret) {
910 		dev_err(dev, "Error turning off resources %d\n", ret);
911 		goto err_dma;
912 	}
913 
914 	ret = geni_icc_disable(&gi2c->se);
915 	if (ret)
916 		goto err_dma;
917 
918 	gi2c->suspended = 1;
919 	pm_runtime_set_suspended(gi2c->se.dev);
920 	pm_runtime_set_autosuspend_delay(gi2c->se.dev, I2C_AUTO_SUSPEND_DELAY);
921 	pm_runtime_use_autosuspend(gi2c->se.dev);
922 	pm_runtime_enable(gi2c->se.dev);
923 
924 	ret = i2c_add_adapter(&gi2c->adap);
925 	if (ret) {
926 		dev_err(dev, "Error adding i2c adapter %d\n", ret);
927 		pm_runtime_disable(gi2c->se.dev);
928 		goto err_dma;
929 	}
930 
931 	dev_dbg(dev, "Geni-I2C adaptor successfully added\n");
932 
933 	return 0;
934 
935 err_dma:
936 	release_gpi_dma(gi2c);
937 	return ret;
938 }
939 
geni_i2c_remove(struct platform_device * pdev)940 static void geni_i2c_remove(struct platform_device *pdev)
941 {
942 	struct geni_i2c_dev *gi2c = platform_get_drvdata(pdev);
943 
944 	i2c_del_adapter(&gi2c->adap);
945 	release_gpi_dma(gi2c);
946 	pm_runtime_disable(gi2c->se.dev);
947 }
948 
geni_i2c_shutdown(struct platform_device * pdev)949 static void geni_i2c_shutdown(struct platform_device *pdev)
950 {
951 	struct geni_i2c_dev *gi2c = platform_get_drvdata(pdev);
952 
953 	/* Make client i2c transfers start failing */
954 	i2c_mark_adapter_suspended(&gi2c->adap);
955 }
956 
geni_i2c_runtime_suspend(struct device * dev)957 static int __maybe_unused geni_i2c_runtime_suspend(struct device *dev)
958 {
959 	int ret;
960 	struct geni_i2c_dev *gi2c = dev_get_drvdata(dev);
961 
962 	disable_irq(gi2c->irq);
963 	ret = geni_se_resources_off(&gi2c->se);
964 	if (ret) {
965 		enable_irq(gi2c->irq);
966 		return ret;
967 
968 	} else {
969 		gi2c->suspended = 1;
970 	}
971 
972 	clk_disable_unprepare(gi2c->core_clk);
973 
974 	return geni_icc_disable(&gi2c->se);
975 }
976 
geni_i2c_runtime_resume(struct device * dev)977 static int __maybe_unused geni_i2c_runtime_resume(struct device *dev)
978 {
979 	int ret;
980 	struct geni_i2c_dev *gi2c = dev_get_drvdata(dev);
981 
982 	ret = geni_icc_enable(&gi2c->se);
983 	if (ret)
984 		return ret;
985 
986 	ret = clk_prepare_enable(gi2c->core_clk);
987 	if (ret)
988 		goto out_icc_disable;
989 
990 	ret = geni_se_resources_on(&gi2c->se);
991 	if (ret)
992 		goto out_clk_disable;
993 
994 	enable_irq(gi2c->irq);
995 	gi2c->suspended = 0;
996 
997 	return 0;
998 
999 out_clk_disable:
1000 	clk_disable_unprepare(gi2c->core_clk);
1001 out_icc_disable:
1002 	geni_icc_disable(&gi2c->se);
1003 
1004 	return ret;
1005 }
1006 
geni_i2c_suspend_noirq(struct device * dev)1007 static int __maybe_unused geni_i2c_suspend_noirq(struct device *dev)
1008 {
1009 	struct geni_i2c_dev *gi2c = dev_get_drvdata(dev);
1010 
1011 	i2c_mark_adapter_suspended(&gi2c->adap);
1012 
1013 	if (!gi2c->suspended) {
1014 		geni_i2c_runtime_suspend(dev);
1015 		pm_runtime_disable(dev);
1016 		pm_runtime_set_suspended(dev);
1017 		pm_runtime_enable(dev);
1018 	}
1019 	return 0;
1020 }
1021 
geni_i2c_resume_noirq(struct device * dev)1022 static int __maybe_unused geni_i2c_resume_noirq(struct device *dev)
1023 {
1024 	struct geni_i2c_dev *gi2c = dev_get_drvdata(dev);
1025 
1026 	i2c_mark_adapter_resumed(&gi2c->adap);
1027 	return 0;
1028 }
1029 
1030 static const struct dev_pm_ops geni_i2c_pm_ops = {
1031 	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(geni_i2c_suspend_noirq, geni_i2c_resume_noirq)
1032 	SET_RUNTIME_PM_OPS(geni_i2c_runtime_suspend, geni_i2c_runtime_resume,
1033 									NULL)
1034 };
1035 
1036 static const struct geni_i2c_desc i2c_master_hub = {
1037 	.has_core_clk = true,
1038 	.icc_ddr = NULL,
1039 	.no_dma_support = true,
1040 	.tx_fifo_depth = 16,
1041 };
1042 
1043 static const struct of_device_id geni_i2c_dt_match[] = {
1044 	{ .compatible = "qcom,geni-i2c" },
1045 	{ .compatible = "qcom,geni-i2c-master-hub", .data = &i2c_master_hub },
1046 	{}
1047 };
1048 MODULE_DEVICE_TABLE(of, geni_i2c_dt_match);
1049 
1050 static struct platform_driver geni_i2c_driver = {
1051 	.probe  = geni_i2c_probe,
1052 	.remove_new = geni_i2c_remove,
1053 	.shutdown = geni_i2c_shutdown,
1054 	.driver = {
1055 		.name = "geni_i2c",
1056 		.pm = &geni_i2c_pm_ops,
1057 		.of_match_table = geni_i2c_dt_match,
1058 		.acpi_match_table = ACPI_PTR(geni_i2c_acpi_match),
1059 	},
1060 };
1061 
1062 module_platform_driver(geni_i2c_driver);
1063 
1064 MODULE_DESCRIPTION("I2C Controller Driver for GENI based QUP cores");
1065 MODULE_LICENSE("GPL v2");
1066