xref: /openbmc/u-boot/drivers/i2c/rk_i2c.c (revision 83853366)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * (C) Copyright 2015 Google, Inc
4  *
5  * (C) Copyright 2008-2014 Rockchip Electronics
6  * Peter, Software Engineering, <superpeter.cai@gmail.com>.
7  */
8 
9 #include <common.h>
10 #include <clk.h>
11 #include <dm.h>
12 #include <errno.h>
13 #include <i2c.h>
14 #include <asm/io.h>
15 #include <asm/arch/clock.h>
16 #include <asm/arch/i2c.h>
17 #include <asm/arch/periph.h>
18 #include <dm/pinctrl.h>
19 #include <linux/sizes.h>
20 
21 /* i2c timerout */
22 #define I2C_TIMEOUT_MS		100
23 #define I2C_RETRY_COUNT		3
24 
25 /* rk i2c fifo max transfer bytes */
26 #define RK_I2C_FIFO_SIZE	32
27 
28 struct rk_i2c {
29 	struct clk clk;
30 	struct i2c_regs *regs;
31 	unsigned int speed;
32 };
33 
34 enum {
35 	RK_I2C_LEGACY,
36 	RK_I2C_NEW,
37 };
38 
39 /**
40  * @controller_type: i2c controller type
41  */
42 struct rk_i2c_soc_data {
43 	int controller_type;
44 };
45 
46 static inline void rk_i2c_get_div(int div, int *divh, int *divl)
47 {
48 	*divl = div / 2;
49 	if (div % 2 == 0)
50 		*divh = div / 2;
51 	else
52 		*divh = DIV_ROUND_UP(div, 2);
53 }
54 
55 /*
56  * SCL Divisor = 8 * (CLKDIVL+1 + CLKDIVH+1)
57  * SCL = PCLK / SCLK Divisor
58  * i2c_rate = PCLK
59  */
60 static void rk_i2c_set_clk(struct rk_i2c *i2c, uint32_t scl_rate)
61 {
62 	uint32_t i2c_rate;
63 	int div, divl, divh;
64 
65 	/* First get i2c rate from pclk */
66 	i2c_rate = clk_get_rate(&i2c->clk);
67 
68 	div = DIV_ROUND_UP(i2c_rate, scl_rate * 8) - 2;
69 	divh = 0;
70 	divl = 0;
71 	if (div >= 0)
72 		rk_i2c_get_div(div, &divh, &divl);
73 	writel(I2C_CLKDIV_VAL(divl, divh), &i2c->regs->clkdiv);
74 
75 	debug("rk_i2c_set_clk: i2c rate = %d, scl rate = %d\n", i2c_rate,
76 	      scl_rate);
77 	debug("set i2c clk div = %d, divh = %d, divl = %d\n", div, divh, divl);
78 	debug("set clk(I2C_CLKDIV: 0x%08x)\n", readl(&i2c->regs->clkdiv));
79 }
80 
81 static void rk_i2c_show_regs(struct i2c_regs *regs)
82 {
83 #ifdef DEBUG
84 	uint i;
85 
86 	debug("i2c_con: 0x%08x\n", readl(&regs->con));
87 	debug("i2c_clkdiv: 0x%08x\n", readl(&regs->clkdiv));
88 	debug("i2c_mrxaddr: 0x%08x\n", readl(&regs->mrxaddr));
89 	debug("i2c_mrxraddR: 0x%08x\n", readl(&regs->mrxraddr));
90 	debug("i2c_mtxcnt: 0x%08x\n", readl(&regs->mtxcnt));
91 	debug("i2c_mrxcnt: 0x%08x\n", readl(&regs->mrxcnt));
92 	debug("i2c_ien: 0x%08x\n", readl(&regs->ien));
93 	debug("i2c_ipd: 0x%08x\n", readl(&regs->ipd));
94 	debug("i2c_fcnt: 0x%08x\n", readl(&regs->fcnt));
95 	for (i = 0; i < 8; i++)
96 		debug("i2c_txdata%d: 0x%08x\n", i, readl(&regs->txdata[i]));
97 	for (i = 0; i < 8; i++)
98 		debug("i2c_rxdata%d: 0x%08x\n", i, readl(&regs->rxdata[i]));
99 #endif
100 }
101 
102 static int rk_i2c_send_start_bit(struct rk_i2c *i2c)
103 {
104 	struct i2c_regs *regs = i2c->regs;
105 	ulong start;
106 
107 	debug("I2c Send Start bit.\n");
108 	writel(I2C_IPD_ALL_CLEAN, &regs->ipd);
109 
110 	writel(I2C_CON_EN | I2C_CON_START, &regs->con);
111 	writel(I2C_STARTIEN, &regs->ien);
112 
113 	start = get_timer(0);
114 	while (1) {
115 		if (readl(&regs->ipd) & I2C_STARTIPD) {
116 			writel(I2C_STARTIPD, &regs->ipd);
117 			break;
118 		}
119 		if (get_timer(start) > I2C_TIMEOUT_MS) {
120 			debug("I2C Send Start Bit Timeout\n");
121 			rk_i2c_show_regs(regs);
122 			return -ETIMEDOUT;
123 		}
124 		udelay(1);
125 	}
126 
127 	return 0;
128 }
129 
130 static int rk_i2c_send_stop_bit(struct rk_i2c *i2c)
131 {
132 	struct i2c_regs *regs = i2c->regs;
133 	ulong start;
134 
135 	debug("I2c Send Stop bit.\n");
136 	writel(I2C_IPD_ALL_CLEAN, &regs->ipd);
137 
138 	writel(I2C_CON_EN | I2C_CON_STOP, &regs->con);
139 	writel(I2C_CON_STOP, &regs->ien);
140 
141 	start = get_timer(0);
142 	while (1) {
143 		if (readl(&regs->ipd) & I2C_STOPIPD) {
144 			writel(I2C_STOPIPD, &regs->ipd);
145 			break;
146 		}
147 		if (get_timer(start) > I2C_TIMEOUT_MS) {
148 			debug("I2C Send Start Bit Timeout\n");
149 			rk_i2c_show_regs(regs);
150 			return -ETIMEDOUT;
151 		}
152 		udelay(1);
153 	}
154 
155 	return 0;
156 }
157 
158 static inline void rk_i2c_disable(struct rk_i2c *i2c)
159 {
160 	writel(0, &i2c->regs->con);
161 }
162 
163 static int rk_i2c_read(struct rk_i2c *i2c, uchar chip, uint reg, uint r_len,
164 		       uchar *buf, uint b_len)
165 {
166 	struct i2c_regs *regs = i2c->regs;
167 	uchar *pbuf = buf;
168 	uint bytes_remain_len = b_len;
169 	uint bytes_xferred = 0;
170 	uint words_xferred = 0;
171 	ulong start;
172 	uint con = 0;
173 	uint rxdata;
174 	uint i, j;
175 	int err;
176 	bool snd_chunk = false;
177 
178 	debug("rk_i2c_read: chip = %d, reg = %d, r_len = %d, b_len = %d\n",
179 	      chip, reg, r_len, b_len);
180 
181 	err = rk_i2c_send_start_bit(i2c);
182 	if (err)
183 		return err;
184 
185 	writel(I2C_MRXADDR_SET(1, chip << 1 | 1), &regs->mrxaddr);
186 	if (r_len == 0) {
187 		writel(0, &regs->mrxraddr);
188 	} else if (r_len < 4) {
189 		writel(I2C_MRXRADDR_SET(r_len, reg), &regs->mrxraddr);
190 	} else {
191 		debug("I2C Read: addr len %d not supported\n", r_len);
192 		return -EIO;
193 	}
194 
195 	while (bytes_remain_len) {
196 		if (bytes_remain_len > RK_I2C_FIFO_SIZE) {
197 			con = I2C_CON_EN;
198 			bytes_xferred = 32;
199 		} else {
200 			/*
201 			 * The hw can read up to 32 bytes at a time. If we need
202 			 * more than one chunk, send an ACK after the last byte.
203 			 */
204 			con = I2C_CON_EN | I2C_CON_LASTACK;
205 			bytes_xferred = bytes_remain_len;
206 		}
207 		words_xferred = DIV_ROUND_UP(bytes_xferred, 4);
208 
209 		/*
210 		 * make sure we are in plain RX mode if we read a second chunk
211 		 */
212 		if (snd_chunk)
213 			con |= I2C_CON_MOD(I2C_MODE_RX);
214 		else
215 			con |= I2C_CON_MOD(I2C_MODE_TRX);
216 
217 		writel(con, &regs->con);
218 		writel(bytes_xferred, &regs->mrxcnt);
219 		writel(I2C_MBRFIEN | I2C_NAKRCVIEN, &regs->ien);
220 
221 		start = get_timer(0);
222 		while (1) {
223 			if (readl(&regs->ipd) & I2C_NAKRCVIPD) {
224 				writel(I2C_NAKRCVIPD, &regs->ipd);
225 				err = -EREMOTEIO;
226 			}
227 			if (readl(&regs->ipd) & I2C_MBRFIPD) {
228 				writel(I2C_MBRFIPD, &regs->ipd);
229 				break;
230 			}
231 			if (get_timer(start) > I2C_TIMEOUT_MS) {
232 				debug("I2C Read Data Timeout\n");
233 				err =  -ETIMEDOUT;
234 				rk_i2c_show_regs(regs);
235 				goto i2c_exit;
236 			}
237 			udelay(1);
238 		}
239 
240 		for (i = 0; i < words_xferred; i++) {
241 			rxdata = readl(&regs->rxdata[i]);
242 			debug("I2c Read RXDATA[%d] = 0x%x\n", i, rxdata);
243 			for (j = 0; j < 4; j++) {
244 				if ((i * 4 + j) == bytes_xferred)
245 					break;
246 				*pbuf++ = (rxdata >> (j * 8)) & 0xff;
247 			}
248 		}
249 
250 		bytes_remain_len -= bytes_xferred;
251 		snd_chunk = true;
252 		debug("I2C Read bytes_remain_len %d\n", bytes_remain_len);
253 	}
254 
255 i2c_exit:
256 	rk_i2c_send_stop_bit(i2c);
257 	rk_i2c_disable(i2c);
258 
259 	return err;
260 }
261 
262 static int rk_i2c_write(struct rk_i2c *i2c, uchar chip, uint reg, uint r_len,
263 			uchar *buf, uint b_len)
264 {
265 	struct i2c_regs *regs = i2c->regs;
266 	int err;
267 	uchar *pbuf = buf;
268 	uint bytes_remain_len = b_len + r_len + 1;
269 	uint bytes_xferred = 0;
270 	uint words_xferred = 0;
271 	ulong start;
272 	uint txdata;
273 	uint i, j;
274 
275 	debug("rk_i2c_write: chip = %d, reg = %d, r_len = %d, b_len = %d\n",
276 	      chip, reg, r_len, b_len);
277 	err = rk_i2c_send_start_bit(i2c);
278 	if (err)
279 		return err;
280 
281 	while (bytes_remain_len) {
282 		if (bytes_remain_len > RK_I2C_FIFO_SIZE)
283 			bytes_xferred = RK_I2C_FIFO_SIZE;
284 		else
285 			bytes_xferred = bytes_remain_len;
286 		words_xferred = DIV_ROUND_UP(bytes_xferred, 4);
287 
288 		for (i = 0; i < words_xferred; i++) {
289 			txdata = 0;
290 			for (j = 0; j < 4; j++) {
291 				if ((i * 4 + j) == bytes_xferred)
292 					break;
293 
294 				if (i == 0 && j == 0 && pbuf == buf) {
295 					txdata |= (chip << 1);
296 				} else if (i == 0 && j <= r_len && pbuf == buf) {
297 					txdata |= (reg &
298 						(0xff << ((j - 1) * 8))) << 8;
299 				} else {
300 					txdata |= (*pbuf++)<<(j * 8);
301 				}
302 			}
303 			writel(txdata, &regs->txdata[i]);
304 			debug("I2c Write TXDATA[%d] = 0x%08x\n", i, txdata);
305 		}
306 
307 		writel(I2C_CON_EN | I2C_CON_MOD(I2C_MODE_TX), &regs->con);
308 		writel(bytes_xferred, &regs->mtxcnt);
309 		writel(I2C_MBTFIEN | I2C_NAKRCVIEN, &regs->ien);
310 
311 		start = get_timer(0);
312 		while (1) {
313 			if (readl(&regs->ipd) & I2C_NAKRCVIPD) {
314 				writel(I2C_NAKRCVIPD, &regs->ipd);
315 				err = -EREMOTEIO;
316 			}
317 			if (readl(&regs->ipd) & I2C_MBTFIPD) {
318 				writel(I2C_MBTFIPD, &regs->ipd);
319 				break;
320 			}
321 			if (get_timer(start) > I2C_TIMEOUT_MS) {
322 				debug("I2C Write Data Timeout\n");
323 				err =  -ETIMEDOUT;
324 				rk_i2c_show_regs(regs);
325 				goto i2c_exit;
326 			}
327 			udelay(1);
328 		}
329 
330 		bytes_remain_len -= bytes_xferred;
331 		debug("I2C Write bytes_remain_len %d\n", bytes_remain_len);
332 	}
333 
334 i2c_exit:
335 	rk_i2c_send_stop_bit(i2c);
336 	rk_i2c_disable(i2c);
337 
338 	return err;
339 }
340 
341 static int rockchip_i2c_xfer(struct udevice *bus, struct i2c_msg *msg,
342 			     int nmsgs)
343 {
344 	struct rk_i2c *i2c = dev_get_priv(bus);
345 	int ret;
346 
347 	debug("i2c_xfer: %d messages\n", nmsgs);
348 	for (; nmsgs > 0; nmsgs--, msg++) {
349 		debug("i2c_xfer: chip=0x%x, len=0x%x\n", msg->addr, msg->len);
350 		if (msg->flags & I2C_M_RD) {
351 			ret = rk_i2c_read(i2c, msg->addr, 0, 0, msg->buf,
352 					  msg->len);
353 		} else {
354 			ret = rk_i2c_write(i2c, msg->addr, 0, 0, msg->buf,
355 					   msg->len);
356 		}
357 		if (ret) {
358 			debug("i2c_write: error sending\n");
359 			return -EREMOTEIO;
360 		}
361 	}
362 
363 	return 0;
364 }
365 
366 int rockchip_i2c_set_bus_speed(struct udevice *bus, unsigned int speed)
367 {
368 	struct rk_i2c *i2c = dev_get_priv(bus);
369 
370 	rk_i2c_set_clk(i2c, speed);
371 
372 	return 0;
373 }
374 
375 static int rockchip_i2c_ofdata_to_platdata(struct udevice *bus)
376 {
377 	struct rk_i2c *priv = dev_get_priv(bus);
378 	int ret;
379 
380 	ret = clk_get_by_index(bus, 0, &priv->clk);
381 	if (ret < 0) {
382 		debug("%s: Could not get clock for %s: %d\n", __func__,
383 		      bus->name, ret);
384 		return ret;
385 	}
386 
387 	return 0;
388 }
389 
390 static int rockchip_i2c_probe(struct udevice *bus)
391 {
392 	struct rk_i2c *priv = dev_get_priv(bus);
393 	struct rk_i2c_soc_data *soc_data;
394 	struct udevice *pinctrl;
395 	int bus_nr;
396 	int ret;
397 
398 	priv->regs = dev_read_addr_ptr(bus);
399 
400 	soc_data = (struct rk_i2c_soc_data*)dev_get_driver_data(bus);
401 
402 	if (soc_data->controller_type == RK_I2C_LEGACY) {
403 		ret = dev_read_alias_seq(bus, &bus_nr);
404 		if (ret < 0) {
405 			debug("%s: Could not get alias for %s: %d\n",
406 			 __func__, bus->name, ret);
407 			return ret;
408 		}
409 
410 		ret = uclass_get_device(UCLASS_PINCTRL, 0, &pinctrl);
411 		if (ret) {
412 			debug("%s: Cannot find pinctrl device\n", __func__);
413 			return ret;
414 		}
415 
416 		/* pinctrl will switch I2C to new type */
417 		ret = pinctrl_request_noflags(pinctrl, PERIPH_ID_I2C0 + bus_nr);
418 		if (ret) {
419 			debug("%s: Failed to switch I2C to new type %s: %d\n",
420 				__func__, bus->name, ret);
421 			return ret;
422 		}
423 	}
424 
425 	return 0;
426 }
427 
428 static const struct dm_i2c_ops rockchip_i2c_ops = {
429 	.xfer		= rockchip_i2c_xfer,
430 	.set_bus_speed	= rockchip_i2c_set_bus_speed,
431 };
432 
433 static const struct rk_i2c_soc_data rk3066_soc_data = {
434 	.controller_type = RK_I2C_LEGACY,
435 };
436 
437 static const struct rk_i2c_soc_data rk3188_soc_data = {
438 	.controller_type = RK_I2C_LEGACY,
439 };
440 
441 static const struct rk_i2c_soc_data rk3228_soc_data = {
442 	.controller_type = RK_I2C_NEW,
443 };
444 
445 static const struct rk_i2c_soc_data rk3288_soc_data = {
446 	.controller_type = RK_I2C_NEW,
447 };
448 
449 static const struct rk_i2c_soc_data rk3328_soc_data = {
450 	.controller_type = RK_I2C_NEW,
451 };
452 
453 static const struct rk_i2c_soc_data rk3399_soc_data = {
454 	.controller_type = RK_I2C_NEW,
455 };
456 
457 static const struct udevice_id rockchip_i2c_ids[] = {
458 	{
459 		.compatible = "rockchip,rk3066-i2c",
460 		.data = (ulong)&rk3066_soc_data,
461 	},
462 	{
463 		.compatible = "rockchip,rk3188-i2c",
464 		.data = (ulong)&rk3188_soc_data,
465 	},
466 	{
467 		.compatible = "rockchip,rk3228-i2c",
468 		.data = (ulong)&rk3228_soc_data,
469 	},
470 	{
471 		.compatible = "rockchip,rk3288-i2c",
472 		.data = (ulong)&rk3288_soc_data,
473 	},
474 	{
475 		.compatible = "rockchip,rk3328-i2c",
476 		.data = (ulong)&rk3328_soc_data,
477 	},
478 	{
479 		.compatible = "rockchip,rk3399-i2c",
480 		.data = (ulong)&rk3399_soc_data,
481 	},
482 	{ }
483 };
484 
485 U_BOOT_DRIVER(i2c_rockchip) = {
486 	.name	= "i2c_rockchip",
487 	.id	= UCLASS_I2C,
488 	.of_match = rockchip_i2c_ids,
489 	.ofdata_to_platdata = rockchip_i2c_ofdata_to_platdata,
490 	.probe	= rockchip_i2c_probe,
491 	.priv_auto_alloc_size = sizeof(struct rk_i2c),
492 	.ops	= &rockchip_i2c_ops,
493 };
494