xref: /openbmc/u-boot/drivers/i2c/ihs_i2c.c (revision d024236e5a31a2b4b82cbcc98b31b8170fc88d28)
1 /*
2  * (C) Copyright 2013
3  * Dirk Eibach,  Guntermann & Drunck GmbH, dirk.eibach@gdsys.cc
4  *
5  * SPDX-License-Identifier:	GPL-2.0+
6  */
7 
8 #include <common.h>
9 #include <i2c.h>
10 #ifdef CONFIG_DM_I2C
11 #include <dm.h>
12 #include <fpgamap.h>
13 #include "../misc/gdsys_soc.h"
14 #else
15 #include <gdsys_fpga.h>
16 #endif
17 #include <asm/unaligned.h>
18 
19 #ifdef CONFIG_DM_I2C
20 struct ihs_i2c_priv {
21 	uint speed;
22 	phys_addr_t addr;
23 };
24 
25 enum {
26 	REG_INTERRUPT_STATUS = 0x00,
27 	REG_INTERRUPT_ENABLE_CONTROL = 0x02,
28 	REG_WRITE_MAILBOX_EXT = 0x04,
29 	REG_WRITE_MAILBOX = 0x06,
30 	REG_READ_MAILBOX_EXT = 0x08,
31 	REG_READ_MAILBOX = 0x0A,
32 };
33 
34 #else /* !CONFIG_DM_I2C */
35 DECLARE_GLOBAL_DATA_PTR;
36 
37 #ifdef CONFIG_SYS_I2C_IHS_DUAL
38 
39 #define I2C_SET_REG(fld, val) \
40 	do { \
41 		if (I2C_ADAP_HWNR & 0x10) \
42 			FPGA_SET_REG(I2C_ADAP_HWNR & 0xf, i2c1.fld, val); \
43 		else \
44 			FPGA_SET_REG(I2C_ADAP_HWNR, i2c0.fld, val); \
45 	} while (0)
46 #else
47 #define I2C_SET_REG(fld, val) \
48 		FPGA_SET_REG(I2C_ADAP_HWNR, i2c0.fld, val)
49 #endif
50 
51 #ifdef CONFIG_SYS_I2C_IHS_DUAL
52 #define I2C_GET_REG(fld, val) \
53 	do {					\
54 		if (I2C_ADAP_HWNR & 0x10) \
55 			FPGA_GET_REG(I2C_ADAP_HWNR & 0xf, i2c1.fld, val); \
56 		else \
57 			FPGA_GET_REG(I2C_ADAP_HWNR, i2c0.fld, val); \
58 	} while (0)
59 #else
60 #define I2C_GET_REG(fld, val) \
61 		FPGA_GET_REG(I2C_ADAP_HWNR, i2c0.fld, val)
62 #endif
63 #endif /* CONFIG_DM_I2C */
64 
65 enum {
66 	I2CINT_ERROR_EV = BIT(13),
67 	I2CINT_TRANSMIT_EV = BIT(14),
68 	I2CINT_RECEIVE_EV = BIT(15),
69 };
70 
71 enum {
72 	I2CMB_READ = 0 << 10,
73 	I2CMB_WRITE = 1 << 10,
74 	I2CMB_1BYTE = 0 << 11,
75 	I2CMB_2BYTE = 1 << 11,
76 	I2CMB_DONT_HOLD_BUS = 0 << 13,
77 	I2CMB_HOLD_BUS = 1 << 13,
78 	I2CMB_NATIVE = 2 << 14,
79 };
80 
81 enum {
82 	I2COP_WRITE = 0,
83 	I2COP_READ = 1,
84 };
85 
86 #ifdef CONFIG_DM_I2C
87 static int wait_for_int(struct udevice *dev, int read)
88 #else
89 static int wait_for_int(bool read)
90 #endif
91 {
92 	u16 val;
93 	uint ctr = 0;
94 #ifdef CONFIG_DM_I2C
95 	struct ihs_i2c_priv *priv = dev_get_priv(dev);
96 	struct udevice *fpga;
97 
98 	gdsys_soc_get_fpga(dev, &fpga);
99 #endif
100 
101 #ifdef CONFIG_DM_I2C
102 	fpgamap_read(fpga, priv->addr + REG_INTERRUPT_STATUS, &val,
103 		     FPGAMAP_SIZE_16);
104 #else
105 	I2C_GET_REG(interrupt_status, &val);
106 #endif
107 	/* Wait until error or receive/transmit interrupt was raised */
108 	while (!(val & (I2CINT_ERROR_EV
109 	       | (read ? I2CINT_RECEIVE_EV : I2CINT_TRANSMIT_EV)))) {
110 		udelay(10);
111 		if (ctr++ > 5000)
112 			return 1;
113 #ifdef CONFIG_DM_I2C
114 		fpgamap_read(fpga, priv->addr + REG_INTERRUPT_STATUS, &val,
115 			     FPGAMAP_SIZE_16);
116 #else
117 		I2C_GET_REG(interrupt_status, &val);
118 #endif
119 	}
120 
121 	return (val & I2CINT_ERROR_EV) ? 1 : 0;
122 }
123 
124 #ifdef CONFIG_DM_I2C
125 static int ihs_i2c_transfer(struct udevice *dev, uchar chip,
126 			    uchar *buffer, int len, int read, bool is_last)
127 #else
128 static int ihs_i2c_transfer(uchar chip, uchar *buffer, int len, bool read,
129 			    bool is_last)
130 #endif
131 {
132 	u16 val;
133 	u16 data;
134 #ifdef CONFIG_DM_I2C
135 	struct ihs_i2c_priv *priv = dev_get_priv(dev);
136 	struct udevice *fpga;
137 
138 	gdsys_soc_get_fpga(dev, &fpga);
139 #endif
140 
141 	/* Clear interrupt status */
142 	data = I2CINT_ERROR_EV | I2CINT_RECEIVE_EV | I2CINT_TRANSMIT_EV;
143 #ifdef CONFIG_DM_I2C
144 	fpgamap_write(fpga, priv->addr + REG_INTERRUPT_STATUS, &data,
145 		      FPGAMAP_SIZE_16);
146 	fpgamap_read(fpga, priv->addr + REG_INTERRUPT_STATUS, &val,
147 		     FPGAMAP_SIZE_16);
148 #else
149 	I2C_SET_REG(interrupt_status, data);
150 	I2C_GET_REG(interrupt_status, &val);
151 #endif
152 
153 	/* If we want to write and have data, write the bytes to the mailbox */
154 	if (!read && len) {
155 		val = buffer[0];
156 
157 		if (len > 1)
158 			val |= buffer[1] << 8;
159 #ifdef CONFIG_DM_I2C
160 		fpgamap_write(fpga, priv->addr + REG_WRITE_MAILBOX_EXT, &val,
161 			      FPGAMAP_SIZE_16);
162 #else
163 		I2C_SET_REG(write_mailbox_ext, val);
164 #endif
165 	}
166 
167 	data = I2CMB_NATIVE
168 	       | (read ? 0 : I2CMB_WRITE)
169 	       | (chip << 1)
170 	       | ((len > 1) ? I2CMB_2BYTE : 0)
171 	       | (is_last ? 0 : I2CMB_HOLD_BUS);
172 
173 #ifdef CONFIG_DM_I2C
174 	fpgamap_write(fpga, priv->addr + REG_WRITE_MAILBOX, &data,
175 		      FPGAMAP_SIZE_16);
176 #else
177 	I2C_SET_REG(write_mailbox, data);
178 #endif
179 
180 #ifdef CONFIG_DM_I2C
181 	if (wait_for_int(dev, read))
182 #else
183 	if (wait_for_int(read))
184 #endif
185 		return 1;
186 
187 	/* If we want to read, get the bytes from the mailbox */
188 	if (read) {
189 #ifdef CONFIG_DM_I2C
190 		fpgamap_read(fpga, priv->addr + REG_READ_MAILBOX_EXT, &val,
191 			     FPGAMAP_SIZE_16);
192 #else
193 		I2C_GET_REG(read_mailbox_ext, &val);
194 #endif
195 		buffer[0] = val & 0xff;
196 		if (len > 1)
197 			buffer[1] = val >> 8;
198 	}
199 
200 	return 0;
201 }
202 
203 #ifdef CONFIG_DM_I2C
204 static int ihs_i2c_send_buffer(struct udevice *dev, uchar chip, u8 *data, int len, bool hold_bus, int read)
205 #else
206 static int ihs_i2c_send_buffer(uchar chip, u8 *data, int len, bool hold_bus,
207 			       int read)
208 #endif
209 {
210 	while (len) {
211 		int transfer = min(len, 2);
212 		bool is_last = len <= transfer;
213 
214 #ifdef CONFIG_DM_I2C
215 		if (ihs_i2c_transfer(dev, chip, data, transfer, read,
216 				     hold_bus ? false : is_last))
217 			return 1;
218 #else
219 		if (ihs_i2c_transfer(chip, data, transfer, read,
220 				     hold_bus ? false : is_last))
221 			return 1;
222 #endif
223 
224 		data += transfer;
225 		len -= transfer;
226 	}
227 
228 	return 0;
229 }
230 
231 #ifdef CONFIG_DM_I2C
232 static int ihs_i2c_address(struct udevice *dev, uchar chip, u8 *addr, int alen,
233 			   bool hold_bus)
234 #else
235 static int ihs_i2c_address(uchar chip, u8 *addr, int alen, bool hold_bus)
236 #endif
237 {
238 #ifdef CONFIG_DM_I2C
239 	return ihs_i2c_send_buffer(dev, chip, addr, alen, hold_bus, I2COP_WRITE);
240 #else
241 	return ihs_i2c_send_buffer(chip, addr, alen, hold_bus, I2COP_WRITE);
242 #endif
243 }
244 
245 #ifdef CONFIG_DM_I2C
246 static int ihs_i2c_access(struct udevice *dev, uchar chip, u8 *addr,
247 			  int alen, uchar *buffer, int len, int read)
248 #else
249 static int ihs_i2c_access(struct i2c_adapter *adap, uchar chip, u8 *addr,
250 			  int alen, uchar *buffer, int len, int read)
251 #endif
252 {
253 	/* Don't hold the bus if length of data to send/receive is zero */
254 #ifdef CONFIG_DM_I2C
255 	if (len <= 0 || ihs_i2c_address(dev, chip, addr, alen, len))
256 		return 1;
257 #else
258 	if (len <= 0 || ihs_i2c_address(chip, addr, alen, len))
259 		return 1;
260 #endif
261 
262 #ifdef CONFIG_DM_I2C
263 	return ihs_i2c_send_buffer(dev, chip, buffer, len, false, read);
264 #else
265 	return ihs_i2c_send_buffer(chip, buffer, len, false, read);
266 #endif
267 }
268 
269 #ifdef CONFIG_DM_I2C
270 
271 int ihs_i2c_probe(struct udevice *bus)
272 {
273 	struct ihs_i2c_priv *priv = dev_get_priv(bus);
274 	int addr;
275 
276 	addr = dev_read_u32_default(bus, "reg", -1);
277 
278 	priv->addr = addr;
279 
280 	return 0;
281 }
282 
283 static int ihs_i2c_set_bus_speed(struct udevice *bus, uint speed)
284 {
285 	struct ihs_i2c_priv *priv = dev_get_priv(bus);
286 
287 	if (speed != priv->speed && priv->speed != 0)
288 		return 1;
289 
290 	priv->speed = speed;
291 
292 	return 0;
293 }
294 
295 static int ihs_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs)
296 {
297 	struct i2c_msg *dmsg, *omsg, dummy;
298 
299 	memset(&dummy, 0, sizeof(struct i2c_msg));
300 
301 	/* We expect either two messages (one with an offset and one with the
302 	 * actucal data) or one message (just data)
303 	 */
304 	if (nmsgs > 2 || nmsgs == 0) {
305 		debug("%s: Only one or two messages are supported.", __func__);
306 		return -1;
307 	}
308 
309 	omsg = nmsgs == 1 ? &dummy : msg;
310 	dmsg = nmsgs == 1 ? msg : msg + 1;
311 
312 	if (dmsg->flags & I2C_M_RD)
313 		return ihs_i2c_access(bus, dmsg->addr, omsg->buf,
314 				      omsg->len, dmsg->buf, dmsg->len,
315 				      I2COP_READ);
316 	else
317 		return ihs_i2c_access(bus, dmsg->addr, omsg->buf,
318 				      omsg->len, dmsg->buf, dmsg->len,
319 				      I2COP_WRITE);
320 }
321 
322 static int ihs_i2c_probe_chip(struct udevice *bus, u32 chip_addr,
323 			      u32 chip_flags)
324 {
325 	uchar buffer[2];
326 
327 	if (ihs_i2c_transfer(bus, chip_addr, buffer, 0, I2COP_READ, true))
328 		return 1;
329 
330 	return 0;
331 }
332 
333 static const struct dm_i2c_ops ihs_i2c_ops = {
334 	.xfer           = ihs_i2c_xfer,
335 	.probe_chip     = ihs_i2c_probe_chip,
336 	.set_bus_speed  = ihs_i2c_set_bus_speed,
337 };
338 
339 static const struct udevice_id ihs_i2c_ids[] = {
340 	{ .compatible = "gdsys,ihs_i2cmaster", },
341 	{ /* sentinel */ }
342 };
343 
344 U_BOOT_DRIVER(i2c_ihs) = {
345 	.name = "i2c_ihs",
346 	.id = UCLASS_I2C,
347 	.of_match = ihs_i2c_ids,
348 	.probe = ihs_i2c_probe,
349 	.priv_auto_alloc_size = sizeof(struct ihs_i2c_priv),
350 	.ops = &ihs_i2c_ops,
351 };
352 
353 #else /* CONFIG_DM_I2C */
354 
355 static void ihs_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr)
356 {
357 #ifdef CONFIG_SYS_I2C_INIT_BOARD
358 	/*
359 	 * Call board specific i2c bus reset routine before accessing the
360 	 * environment, which might be in a chip on that bus. For details
361 	 * about this problem see doc/I2C_Edge_Conditions.
362 	 */
363 	i2c_init_board();
364 #endif
365 }
366 
367 static int ihs_i2c_probe(struct i2c_adapter *adap, uchar chip)
368 {
369 	uchar buffer[2];
370 
371 	if (ihs_i2c_transfer(chip, buffer, 0, I2COP_READ, true))
372 		return 1;
373 
374 	return 0;
375 }
376 
377 static int ihs_i2c_read(struct i2c_adapter *adap, uchar chip, uint addr,
378 			int alen, uchar *buffer, int len)
379 {
380 	u8 addr_bytes[4];
381 
382 	put_unaligned_le32(addr, addr_bytes);
383 
384 	return ihs_i2c_access(adap, chip, addr_bytes, alen, buffer, len,
385 			      I2COP_READ);
386 }
387 
388 static int ihs_i2c_write(struct i2c_adapter *adap, uchar chip, uint addr,
389 			 int alen, uchar *buffer, int len)
390 {
391 	u8 addr_bytes[4];
392 
393 	put_unaligned_le32(addr, addr_bytes);
394 
395 	return ihs_i2c_access(adap, chip, addr_bytes, alen, buffer, len,
396 			      I2COP_WRITE);
397 }
398 
399 static unsigned int ihs_i2c_set_bus_speed(struct i2c_adapter *adap,
400 					  unsigned int speed)
401 {
402 	if (speed != adap->speed)
403 		return 1;
404 	return speed;
405 }
406 
407 /*
408  * Register IHS i2c adapters
409  */
410 #ifdef CONFIG_SYS_I2C_IHS_CH0
411 U_BOOT_I2C_ADAP_COMPLETE(ihs0, ihs_i2c_init, ihs_i2c_probe,
412 			 ihs_i2c_read, ihs_i2c_write,
413 			 ihs_i2c_set_bus_speed,
414 			 CONFIG_SYS_I2C_IHS_SPEED_0,
415 			 CONFIG_SYS_I2C_IHS_SLAVE_0, 0)
416 #ifdef CONFIG_SYS_I2C_IHS_DUAL
417 U_BOOT_I2C_ADAP_COMPLETE(ihs0_1, ihs_i2c_init, ihs_i2c_probe,
418 			 ihs_i2c_read, ihs_i2c_write,
419 			 ihs_i2c_set_bus_speed,
420 			 CONFIG_SYS_I2C_IHS_SPEED_0_1,
421 			 CONFIG_SYS_I2C_IHS_SLAVE_0_1, 16)
422 #endif
423 #endif
424 #ifdef CONFIG_SYS_I2C_IHS_CH1
425 U_BOOT_I2C_ADAP_COMPLETE(ihs1, ihs_i2c_init, ihs_i2c_probe,
426 			 ihs_i2c_read, ihs_i2c_write,
427 			 ihs_i2c_set_bus_speed,
428 			 CONFIG_SYS_I2C_IHS_SPEED_1,
429 			 CONFIG_SYS_I2C_IHS_SLAVE_1, 1)
430 #ifdef CONFIG_SYS_I2C_IHS_DUAL
431 U_BOOT_I2C_ADAP_COMPLETE(ihs1_1, ihs_i2c_init, ihs_i2c_probe,
432 			 ihs_i2c_read, ihs_i2c_write,
433 			 ihs_i2c_set_bus_speed,
434 			 CONFIG_SYS_I2C_IHS_SPEED_1_1,
435 			 CONFIG_SYS_I2C_IHS_SLAVE_1_1, 17)
436 #endif
437 #endif
438 #ifdef CONFIG_SYS_I2C_IHS_CH2
439 U_BOOT_I2C_ADAP_COMPLETE(ihs2, ihs_i2c_init, ihs_i2c_probe,
440 			 ihs_i2c_read, ihs_i2c_write,
441 			 ihs_i2c_set_bus_speed,
442 			 CONFIG_SYS_I2C_IHS_SPEED_2,
443 			 CONFIG_SYS_I2C_IHS_SLAVE_2, 2)
444 #ifdef CONFIG_SYS_I2C_IHS_DUAL
445 U_BOOT_I2C_ADAP_COMPLETE(ihs2_1, ihs_i2c_init, ihs_i2c_probe,
446 			 ihs_i2c_read, ihs_i2c_write,
447 			 ihs_i2c_set_bus_speed,
448 			 CONFIG_SYS_I2C_IHS_SPEED_2_1,
449 			 CONFIG_SYS_I2C_IHS_SLAVE_2_1, 18)
450 #endif
451 #endif
452 #ifdef CONFIG_SYS_I2C_IHS_CH3
453 U_BOOT_I2C_ADAP_COMPLETE(ihs3, ihs_i2c_init, ihs_i2c_probe,
454 			 ihs_i2c_read, ihs_i2c_write,
455 			 ihs_i2c_set_bus_speed,
456 			 CONFIG_SYS_I2C_IHS_SPEED_3,
457 			 CONFIG_SYS_I2C_IHS_SLAVE_3, 3)
458 #ifdef CONFIG_SYS_I2C_IHS_DUAL
459 U_BOOT_I2C_ADAP_COMPLETE(ihs3_1, ihs_i2c_init, ihs_i2c_probe,
460 			 ihs_i2c_read, ihs_i2c_write,
461 			 ihs_i2c_set_bus_speed,
462 			 CONFIG_SYS_I2C_IHS_SPEED_3_1,
463 			 CONFIG_SYS_I2C_IHS_SLAVE_3_1, 19)
464 #endif
465 #endif
466 #endif /* CONFIG_DM_I2C */
467