xref: /openbmc/u-boot/drivers/i2c/ihs_i2c.c (revision d66ff4ba)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * (C) Copyright 2013
4  * Dirk Eibach,  Guntermann & Drunck GmbH, dirk.eibach@gdsys.cc
5  */
6 
7 #include <common.h>
8 #include <i2c.h>
9 #ifdef CONFIG_DM_I2C
10 #include <dm.h>
11 #include <fpgamap.h>
12 #include "../misc/gdsys_soc.h"
13 #else
14 #include <gdsys_fpga.h>
15 #endif
16 #include <asm/unaligned.h>
17 
18 #ifdef CONFIG_DM_I2C
19 struct ihs_i2c_priv {
20 	uint speed;
21 	phys_addr_t addr;
22 };
23 
24 enum {
25 	REG_INTERRUPT_STATUS = 0x00,
26 	REG_INTERRUPT_ENABLE_CONTROL = 0x02,
27 	REG_WRITE_MAILBOX_EXT = 0x04,
28 	REG_WRITE_MAILBOX = 0x06,
29 	REG_READ_MAILBOX_EXT = 0x08,
30 	REG_READ_MAILBOX = 0x0A,
31 };
32 
33 #else /* !CONFIG_DM_I2C */
34 DECLARE_GLOBAL_DATA_PTR;
35 
36 #ifdef CONFIG_SYS_I2C_IHS_DUAL
37 
38 #define I2C_SET_REG(fld, val) \
39 	do { \
40 		if (I2C_ADAP_HWNR & 0x10) \
41 			FPGA_SET_REG(I2C_ADAP_HWNR & 0xf, i2c1.fld, val); \
42 		else \
43 			FPGA_SET_REG(I2C_ADAP_HWNR, i2c0.fld, val); \
44 	} while (0)
45 #else
46 #define I2C_SET_REG(fld, val) \
47 		FPGA_SET_REG(I2C_ADAP_HWNR, i2c0.fld, val)
48 #endif
49 
50 #ifdef CONFIG_SYS_I2C_IHS_DUAL
51 #define I2C_GET_REG(fld, val) \
52 	do {					\
53 		if (I2C_ADAP_HWNR & 0x10) \
54 			FPGA_GET_REG(I2C_ADAP_HWNR & 0xf, i2c1.fld, val); \
55 		else \
56 			FPGA_GET_REG(I2C_ADAP_HWNR, i2c0.fld, val); \
57 	} while (0)
58 #else
59 #define I2C_GET_REG(fld, val) \
60 		FPGA_GET_REG(I2C_ADAP_HWNR, i2c0.fld, val)
61 #endif
62 #endif /* CONFIG_DM_I2C */
63 
64 enum {
65 	I2CINT_ERROR_EV = BIT(13),
66 	I2CINT_TRANSMIT_EV = BIT(14),
67 	I2CINT_RECEIVE_EV = BIT(15),
68 };
69 
70 enum {
71 	I2CMB_READ = 0 << 10,
72 	I2CMB_WRITE = 1 << 10,
73 	I2CMB_1BYTE = 0 << 11,
74 	I2CMB_2BYTE = 1 << 11,
75 	I2CMB_DONT_HOLD_BUS = 0 << 13,
76 	I2CMB_HOLD_BUS = 1 << 13,
77 	I2CMB_NATIVE = 2 << 14,
78 };
79 
80 enum {
81 	I2COP_WRITE = 0,
82 	I2COP_READ = 1,
83 };
84 
85 #ifdef CONFIG_DM_I2C
86 static int wait_for_int(struct udevice *dev, int read)
87 #else
88 static int wait_for_int(bool read)
89 #endif
90 {
91 	u16 val;
92 	uint ctr = 0;
93 #ifdef CONFIG_DM_I2C
94 	struct ihs_i2c_priv *priv = dev_get_priv(dev);
95 	struct udevice *fpga;
96 
97 	gdsys_soc_get_fpga(dev, &fpga);
98 #endif
99 
100 #ifdef CONFIG_DM_I2C
101 	fpgamap_read(fpga, priv->addr + REG_INTERRUPT_STATUS, &val,
102 		     FPGAMAP_SIZE_16);
103 #else
104 	I2C_GET_REG(interrupt_status, &val);
105 #endif
106 	/* Wait until error or receive/transmit interrupt was raised */
107 	while (!(val & (I2CINT_ERROR_EV
108 	       | (read ? I2CINT_RECEIVE_EV : I2CINT_TRANSMIT_EV)))) {
109 		udelay(10);
110 		if (ctr++ > 5000)
111 			return 1;
112 #ifdef CONFIG_DM_I2C
113 		fpgamap_read(fpga, priv->addr + REG_INTERRUPT_STATUS, &val,
114 			     FPGAMAP_SIZE_16);
115 #else
116 		I2C_GET_REG(interrupt_status, &val);
117 #endif
118 	}
119 
120 	return (val & I2CINT_ERROR_EV) ? 1 : 0;
121 }
122 
123 #ifdef CONFIG_DM_I2C
124 static int ihs_i2c_transfer(struct udevice *dev, uchar chip,
125 			    uchar *buffer, int len, int read, bool is_last)
126 #else
127 static int ihs_i2c_transfer(uchar chip, uchar *buffer, int len, bool read,
128 			    bool is_last)
129 #endif
130 {
131 	u16 val;
132 	u16 data;
133 #ifdef CONFIG_DM_I2C
134 	struct ihs_i2c_priv *priv = dev_get_priv(dev);
135 	struct udevice *fpga;
136 
137 	gdsys_soc_get_fpga(dev, &fpga);
138 #endif
139 
140 	/* Clear interrupt status */
141 	data = I2CINT_ERROR_EV | I2CINT_RECEIVE_EV | I2CINT_TRANSMIT_EV;
142 #ifdef CONFIG_DM_I2C
143 	fpgamap_write(fpga, priv->addr + REG_INTERRUPT_STATUS, &data,
144 		      FPGAMAP_SIZE_16);
145 	fpgamap_read(fpga, priv->addr + REG_INTERRUPT_STATUS, &val,
146 		     FPGAMAP_SIZE_16);
147 #else
148 	I2C_SET_REG(interrupt_status, data);
149 	I2C_GET_REG(interrupt_status, &val);
150 #endif
151 
152 	/* If we want to write and have data, write the bytes to the mailbox */
153 	if (!read && len) {
154 		val = buffer[0];
155 
156 		if (len > 1)
157 			val |= buffer[1] << 8;
158 #ifdef CONFIG_DM_I2C
159 		fpgamap_write(fpga, priv->addr + REG_WRITE_MAILBOX_EXT, &val,
160 			      FPGAMAP_SIZE_16);
161 #else
162 		I2C_SET_REG(write_mailbox_ext, val);
163 #endif
164 	}
165 
166 	data = I2CMB_NATIVE
167 	       | (read ? 0 : I2CMB_WRITE)
168 	       | (chip << 1)
169 	       | ((len > 1) ? I2CMB_2BYTE : 0)
170 	       | (is_last ? 0 : I2CMB_HOLD_BUS);
171 
172 #ifdef CONFIG_DM_I2C
173 	fpgamap_write(fpga, priv->addr + REG_WRITE_MAILBOX, &data,
174 		      FPGAMAP_SIZE_16);
175 #else
176 	I2C_SET_REG(write_mailbox, data);
177 #endif
178 
179 #ifdef CONFIG_DM_I2C
180 	if (wait_for_int(dev, read))
181 #else
182 	if (wait_for_int(read))
183 #endif
184 		return 1;
185 
186 	/* If we want to read, get the bytes from the mailbox */
187 	if (read) {
188 #ifdef CONFIG_DM_I2C
189 		fpgamap_read(fpga, priv->addr + REG_READ_MAILBOX_EXT, &val,
190 			     FPGAMAP_SIZE_16);
191 #else
192 		I2C_GET_REG(read_mailbox_ext, &val);
193 #endif
194 		buffer[0] = val & 0xff;
195 		if (len > 1)
196 			buffer[1] = val >> 8;
197 	}
198 
199 	return 0;
200 }
201 
202 #ifdef CONFIG_DM_I2C
203 static int ihs_i2c_send_buffer(struct udevice *dev, uchar chip, u8 *data, int len, bool hold_bus, int read)
204 #else
205 static int ihs_i2c_send_buffer(uchar chip, u8 *data, int len, bool hold_bus,
206 			       int read)
207 #endif
208 {
209 	while (len) {
210 		int transfer = min(len, 2);
211 		bool is_last = len <= transfer;
212 
213 #ifdef CONFIG_DM_I2C
214 		if (ihs_i2c_transfer(dev, chip, data, transfer, read,
215 				     hold_bus ? false : is_last))
216 			return 1;
217 #else
218 		if (ihs_i2c_transfer(chip, data, transfer, read,
219 				     hold_bus ? false : is_last))
220 			return 1;
221 #endif
222 
223 		data += transfer;
224 		len -= transfer;
225 	}
226 
227 	return 0;
228 }
229 
230 #ifdef CONFIG_DM_I2C
231 static int ihs_i2c_address(struct udevice *dev, uchar chip, u8 *addr, int alen,
232 			   bool hold_bus)
233 #else
234 static int ihs_i2c_address(uchar chip, u8 *addr, int alen, bool hold_bus)
235 #endif
236 {
237 #ifdef CONFIG_DM_I2C
238 	return ihs_i2c_send_buffer(dev, chip, addr, alen, hold_bus, I2COP_WRITE);
239 #else
240 	return ihs_i2c_send_buffer(chip, addr, alen, hold_bus, I2COP_WRITE);
241 #endif
242 }
243 
244 #ifdef CONFIG_DM_I2C
245 static int ihs_i2c_access(struct udevice *dev, uchar chip, u8 *addr,
246 			  int alen, uchar *buffer, int len, int read)
247 #else
248 static int ihs_i2c_access(struct i2c_adapter *adap, uchar chip, u8 *addr,
249 			  int alen, uchar *buffer, int len, int read)
250 #endif
251 {
252 	/* Don't hold the bus if length of data to send/receive is zero */
253 #ifdef CONFIG_DM_I2C
254 	if (len <= 0 || ihs_i2c_address(dev, chip, addr, alen, len))
255 		return 1;
256 #else
257 	if (len <= 0 || ihs_i2c_address(chip, addr, alen, len))
258 		return 1;
259 #endif
260 
261 #ifdef CONFIG_DM_I2C
262 	return ihs_i2c_send_buffer(dev, chip, buffer, len, false, read);
263 #else
264 	return ihs_i2c_send_buffer(chip, buffer, len, false, read);
265 #endif
266 }
267 
268 #ifdef CONFIG_DM_I2C
269 
270 int ihs_i2c_probe(struct udevice *bus)
271 {
272 	struct ihs_i2c_priv *priv = dev_get_priv(bus);
273 	int addr;
274 
275 	addr = dev_read_u32_default(bus, "reg", -1);
276 
277 	priv->addr = addr;
278 
279 	return 0;
280 }
281 
282 static int ihs_i2c_set_bus_speed(struct udevice *bus, uint speed)
283 {
284 	struct ihs_i2c_priv *priv = dev_get_priv(bus);
285 
286 	if (speed != priv->speed && priv->speed != 0)
287 		return 1;
288 
289 	priv->speed = speed;
290 
291 	return 0;
292 }
293 
294 static int ihs_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs)
295 {
296 	struct i2c_msg *dmsg, *omsg, dummy;
297 
298 	memset(&dummy, 0, sizeof(struct i2c_msg));
299 
300 	/* We expect either two messages (one with an offset and one with the
301 	 * actucal data) or one message (just data)
302 	 */
303 	if (nmsgs > 2 || nmsgs == 0) {
304 		debug("%s: Only one or two messages are supported.", __func__);
305 		return -1;
306 	}
307 
308 	omsg = nmsgs == 1 ? &dummy : msg;
309 	dmsg = nmsgs == 1 ? msg : msg + 1;
310 
311 	if (dmsg->flags & I2C_M_RD)
312 		return ihs_i2c_access(bus, dmsg->addr, omsg->buf,
313 				      omsg->len, dmsg->buf, dmsg->len,
314 				      I2COP_READ);
315 	else
316 		return ihs_i2c_access(bus, dmsg->addr, omsg->buf,
317 				      omsg->len, dmsg->buf, dmsg->len,
318 				      I2COP_WRITE);
319 }
320 
321 static int ihs_i2c_probe_chip(struct udevice *bus, u32 chip_addr,
322 			      u32 chip_flags)
323 {
324 	uchar buffer[2];
325 
326 	if (ihs_i2c_transfer(bus, chip_addr, buffer, 0, I2COP_READ, true))
327 		return 1;
328 
329 	return 0;
330 }
331 
332 static const struct dm_i2c_ops ihs_i2c_ops = {
333 	.xfer           = ihs_i2c_xfer,
334 	.probe_chip     = ihs_i2c_probe_chip,
335 	.set_bus_speed  = ihs_i2c_set_bus_speed,
336 };
337 
338 static const struct udevice_id ihs_i2c_ids[] = {
339 	{ .compatible = "gdsys,ihs_i2cmaster", },
340 	{ /* sentinel */ }
341 };
342 
343 U_BOOT_DRIVER(i2c_ihs) = {
344 	.name = "i2c_ihs",
345 	.id = UCLASS_I2C,
346 	.of_match = ihs_i2c_ids,
347 	.probe = ihs_i2c_probe,
348 	.priv_auto_alloc_size = sizeof(struct ihs_i2c_priv),
349 	.ops = &ihs_i2c_ops,
350 };
351 
352 #else /* CONFIG_DM_I2C */
353 
354 static void ihs_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr)
355 {
356 #ifdef CONFIG_SYS_I2C_INIT_BOARD
357 	/*
358 	 * Call board specific i2c bus reset routine before accessing the
359 	 * environment, which might be in a chip on that bus. For details
360 	 * about this problem see doc/I2C_Edge_Conditions.
361 	 */
362 	i2c_init_board();
363 #endif
364 }
365 
366 static int ihs_i2c_probe(struct i2c_adapter *adap, uchar chip)
367 {
368 	uchar buffer[2];
369 
370 	if (ihs_i2c_transfer(chip, buffer, 0, I2COP_READ, true))
371 		return 1;
372 
373 	return 0;
374 }
375 
376 static int ihs_i2c_read(struct i2c_adapter *adap, uchar chip, uint addr,
377 			int alen, uchar *buffer, int len)
378 {
379 	u8 addr_bytes[4];
380 
381 	put_unaligned_le32(addr, addr_bytes);
382 
383 	return ihs_i2c_access(adap, chip, addr_bytes, alen, buffer, len,
384 			      I2COP_READ);
385 }
386 
387 static int ihs_i2c_write(struct i2c_adapter *adap, uchar chip, uint addr,
388 			 int alen, uchar *buffer, int len)
389 {
390 	u8 addr_bytes[4];
391 
392 	put_unaligned_le32(addr, addr_bytes);
393 
394 	return ihs_i2c_access(adap, chip, addr_bytes, alen, buffer, len,
395 			      I2COP_WRITE);
396 }
397 
398 static unsigned int ihs_i2c_set_bus_speed(struct i2c_adapter *adap,
399 					  unsigned int speed)
400 {
401 	if (speed != adap->speed)
402 		return 1;
403 	return speed;
404 }
405 
406 /*
407  * Register IHS i2c adapters
408  */
409 #ifdef CONFIG_SYS_I2C_IHS_CH0
410 U_BOOT_I2C_ADAP_COMPLETE(ihs0, ihs_i2c_init, ihs_i2c_probe,
411 			 ihs_i2c_read, ihs_i2c_write,
412 			 ihs_i2c_set_bus_speed,
413 			 CONFIG_SYS_I2C_IHS_SPEED_0,
414 			 CONFIG_SYS_I2C_IHS_SLAVE_0, 0)
415 #ifdef CONFIG_SYS_I2C_IHS_DUAL
416 U_BOOT_I2C_ADAP_COMPLETE(ihs0_1, ihs_i2c_init, ihs_i2c_probe,
417 			 ihs_i2c_read, ihs_i2c_write,
418 			 ihs_i2c_set_bus_speed,
419 			 CONFIG_SYS_I2C_IHS_SPEED_0_1,
420 			 CONFIG_SYS_I2C_IHS_SLAVE_0_1, 16)
421 #endif
422 #endif
423 #ifdef CONFIG_SYS_I2C_IHS_CH1
424 U_BOOT_I2C_ADAP_COMPLETE(ihs1, ihs_i2c_init, ihs_i2c_probe,
425 			 ihs_i2c_read, ihs_i2c_write,
426 			 ihs_i2c_set_bus_speed,
427 			 CONFIG_SYS_I2C_IHS_SPEED_1,
428 			 CONFIG_SYS_I2C_IHS_SLAVE_1, 1)
429 #ifdef CONFIG_SYS_I2C_IHS_DUAL
430 U_BOOT_I2C_ADAP_COMPLETE(ihs1_1, ihs_i2c_init, ihs_i2c_probe,
431 			 ihs_i2c_read, ihs_i2c_write,
432 			 ihs_i2c_set_bus_speed,
433 			 CONFIG_SYS_I2C_IHS_SPEED_1_1,
434 			 CONFIG_SYS_I2C_IHS_SLAVE_1_1, 17)
435 #endif
436 #endif
437 #ifdef CONFIG_SYS_I2C_IHS_CH2
438 U_BOOT_I2C_ADAP_COMPLETE(ihs2, ihs_i2c_init, ihs_i2c_probe,
439 			 ihs_i2c_read, ihs_i2c_write,
440 			 ihs_i2c_set_bus_speed,
441 			 CONFIG_SYS_I2C_IHS_SPEED_2,
442 			 CONFIG_SYS_I2C_IHS_SLAVE_2, 2)
443 #ifdef CONFIG_SYS_I2C_IHS_DUAL
444 U_BOOT_I2C_ADAP_COMPLETE(ihs2_1, ihs_i2c_init, ihs_i2c_probe,
445 			 ihs_i2c_read, ihs_i2c_write,
446 			 ihs_i2c_set_bus_speed,
447 			 CONFIG_SYS_I2C_IHS_SPEED_2_1,
448 			 CONFIG_SYS_I2C_IHS_SLAVE_2_1, 18)
449 #endif
450 #endif
451 #ifdef CONFIG_SYS_I2C_IHS_CH3
452 U_BOOT_I2C_ADAP_COMPLETE(ihs3, ihs_i2c_init, ihs_i2c_probe,
453 			 ihs_i2c_read, ihs_i2c_write,
454 			 ihs_i2c_set_bus_speed,
455 			 CONFIG_SYS_I2C_IHS_SPEED_3,
456 			 CONFIG_SYS_I2C_IHS_SLAVE_3, 3)
457 #ifdef CONFIG_SYS_I2C_IHS_DUAL
458 U_BOOT_I2C_ADAP_COMPLETE(ihs3_1, ihs_i2c_init, ihs_i2c_probe,
459 			 ihs_i2c_read, ihs_i2c_write,
460 			 ihs_i2c_set_bus_speed,
461 			 CONFIG_SYS_I2C_IHS_SPEED_3_1,
462 			 CONFIG_SYS_I2C_IHS_SLAVE_3_1, 19)
463 #endif
464 #endif
465 #endif /* CONFIG_DM_I2C */
466