xref: /openbmc/u-boot/drivers/i2c/ihs_i2c.c (revision 85231c08)
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_read16(fpga, priv->addr + REG_INTERRUPT_STATUS, &val);
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_read16(fpga, priv->addr + REG_INTERRUPT_STATUS, &val);
114 #else
115 		I2C_GET_REG(interrupt_status, &val);
116 #endif
117 	}
118 
119 	return (val & I2CINT_ERROR_EV) ? 1 : 0;
120 }
121 
122 #ifdef CONFIG_DM_I2C
123 static int ihs_i2c_transfer(struct udevice *dev, uchar chip,
124 			    uchar *buffer, int len, int read, bool is_last)
125 #else
126 static int ihs_i2c_transfer(uchar chip, uchar *buffer, int len, bool read,
127 			    bool is_last)
128 #endif
129 {
130 	u16 val;
131 #ifdef CONFIG_DM_I2C
132 	struct ihs_i2c_priv *priv = dev_get_priv(dev);
133 	struct udevice *fpga;
134 
135 	gdsys_soc_get_fpga(dev, &fpga);
136 #endif
137 
138 	/* Clear interrupt status */
139 #ifdef CONFIG_DM_I2C
140 	fpgamap_write16(fpga, priv->addr + REG_INTERRUPT_STATUS,
141 			I2CINT_ERROR_EV | I2CINT_RECEIVE_EV | I2CINT_TRANSMIT_EV);
142 	fpgamap_read16(fpga, priv->addr + REG_INTERRUPT_STATUS, &val);
143 #else
144 	I2C_SET_REG(interrupt_status, I2CINT_ERROR_EV
145 		     | I2CINT_RECEIVE_EV | I2CINT_TRANSMIT_EV);
146 	I2C_GET_REG(interrupt_status, &val);
147 #endif
148 
149 	/* If we want to write and have data, write the bytes to the mailbox */
150 	if (!read && len) {
151 		val = buffer[0];
152 
153 		if (len > 1)
154 			val |= buffer[1] << 8;
155 #ifdef CONFIG_DM_I2C
156 		fpgamap_write16(fpga, priv->addr + REG_WRITE_MAILBOX_EXT, val);
157 #else
158 		I2C_SET_REG(write_mailbox_ext, val);
159 #endif
160 	}
161 
162 #ifdef CONFIG_DM_I2C
163 	fpgamap_write16(fpga, priv->addr + REG_WRITE_MAILBOX,
164 			I2CMB_NATIVE
165 			| (read ? I2CMB_READ : I2CMB_WRITE)
166 			| (chip << 1)
167 			| ((len > 1) ? I2CMB_2BYTE : I2CMB_1BYTE)
168 			| (!is_last ? I2CMB_HOLD_BUS : I2CMB_DONT_HOLD_BUS));
169 #else
170 	I2C_SET_REG(write_mailbox,
171 		    I2CMB_NATIVE
172 		    | (read ? 0 : I2CMB_WRITE)
173 		    | (chip << 1)
174 		    | ((len > 1) ? I2CMB_2BYTE : 0)
175 		    | (is_last ? 0 : I2CMB_HOLD_BUS));
176 #endif
177 
178 #ifdef CONFIG_DM_I2C
179 	if (wait_for_int(dev, read))
180 #else
181 	if (wait_for_int(read))
182 #endif
183 		return 1;
184 
185 	/* If we want to read, get the bytes from the mailbox */
186 	if (read) {
187 #ifdef CONFIG_DM_I2C
188 		fpgamap_read16(fpga, priv->addr + REG_READ_MAILBOX_EXT, &val);
189 #else
190 		I2C_GET_REG(read_mailbox_ext, &val);
191 #endif
192 		buffer[0] = val & 0xff;
193 		if (len > 1)
194 			buffer[1] = val >> 8;
195 	}
196 
197 	return 0;
198 }
199 
200 #ifdef CONFIG_DM_I2C
201 static int ihs_i2c_send_buffer(struct udevice *dev, uchar chip, u8 *data, int len, bool hold_bus, int read)
202 #else
203 static int ihs_i2c_send_buffer(uchar chip, u8 *data, int len, bool hold_bus,
204 			       int read)
205 #endif
206 {
207 	while (len) {
208 		int transfer = min(len, 2);
209 		bool is_last = len <= transfer;
210 
211 #ifdef CONFIG_DM_I2C
212 		if (ihs_i2c_transfer(dev, chip, data, transfer, read,
213 				     hold_bus ? false : is_last))
214 			return 1;
215 #else
216 		if (ihs_i2c_transfer(chip, data, transfer, read,
217 				     hold_bus ? false : is_last))
218 			return 1;
219 #endif
220 
221 		data += transfer;
222 		len -= transfer;
223 	}
224 
225 	return 0;
226 }
227 
228 #ifdef CONFIG_DM_I2C
229 static int ihs_i2c_address(struct udevice *dev, uchar chip, u8 *addr, int alen,
230 			   bool hold_bus)
231 #else
232 static int ihs_i2c_address(uchar chip, u8 *addr, int alen, bool hold_bus)
233 #endif
234 {
235 #ifdef CONFIG_DM_I2C
236 	return ihs_i2c_send_buffer(dev, chip, addr, alen, hold_bus, I2COP_WRITE);
237 #else
238 	return ihs_i2c_send_buffer(chip, addr, alen, hold_bus, I2COP_WRITE);
239 #endif
240 }
241 
242 #ifdef CONFIG_DM_I2C
243 static int ihs_i2c_access(struct udevice *dev, uchar chip, u8 *addr,
244 			  int alen, uchar *buffer, int len, int read)
245 #else
246 static int ihs_i2c_access(struct i2c_adapter *adap, uchar chip, u8 *addr,
247 			  int alen, uchar *buffer, int len, int read)
248 #endif
249 {
250 	/* Don't hold the bus if length of data to send/receive is zero */
251 #ifdef CONFIG_DM_I2C
252 	if (len <= 0 || ihs_i2c_address(dev, chip, addr, alen, len))
253 		return 1;
254 #else
255 	if (len <= 0 || ihs_i2c_address(chip, addr, alen, len))
256 		return 1;
257 #endif
258 
259 #ifdef CONFIG_DM_I2C
260 	return ihs_i2c_send_buffer(dev, chip, buffer, len, false, read);
261 #else
262 	return ihs_i2c_send_buffer(chip, buffer, len, false, read);
263 #endif
264 }
265 
266 #ifdef CONFIG_DM_I2C
267 
268 int ihs_i2c_probe(struct udevice *bus)
269 {
270 	struct ihs_i2c_priv *priv = dev_get_priv(bus);
271 	int addr;
272 
273 	addr = dev_read_u32_default(bus, "reg", -1);
274 
275 	priv->addr = addr;
276 
277 	return 0;
278 }
279 
280 static int ihs_i2c_set_bus_speed(struct udevice *bus, uint speed)
281 {
282 	struct ihs_i2c_priv *priv = dev_get_priv(bus);
283 
284 	if (speed != priv->speed && priv->speed != 0)
285 		return 1;
286 
287 	priv->speed = speed;
288 
289 	return 0;
290 }
291 
292 static int ihs_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs)
293 {
294 	struct i2c_msg *dmsg, *omsg, dummy;
295 
296 	memset(&dummy, 0, sizeof(struct i2c_msg));
297 
298 	/* We expect either two messages (one with an offset and one with the
299 	 * actucal data) or one message (just data)
300 	 */
301 	if (nmsgs > 2 || nmsgs == 0) {
302 		debug("%s: Only one or two messages are supported.", __func__);
303 		return -1;
304 	}
305 
306 	omsg = nmsgs == 1 ? &dummy : msg;
307 	dmsg = nmsgs == 1 ? msg : msg + 1;
308 
309 	if (dmsg->flags & I2C_M_RD)
310 		return ihs_i2c_access(bus, dmsg->addr, omsg->buf,
311 				      omsg->len, dmsg->buf, dmsg->len,
312 				      I2COP_READ);
313 	else
314 		return ihs_i2c_access(bus, dmsg->addr, omsg->buf,
315 				      omsg->len, dmsg->buf, dmsg->len,
316 				      I2COP_WRITE);
317 }
318 
319 static int ihs_i2c_probe_chip(struct udevice *bus, u32 chip_addr,
320 			      u32 chip_flags)
321 {
322 	uchar buffer[2];
323 
324 	if (ihs_i2c_transfer(bus, chip_addr, buffer, 0, I2COP_READ, true))
325 		return 1;
326 
327 	return 0;
328 }
329 
330 static const struct dm_i2c_ops ihs_i2c_ops = {
331 	.xfer           = ihs_i2c_xfer,
332 	.probe_chip     = ihs_i2c_probe_chip,
333 	.set_bus_speed  = ihs_i2c_set_bus_speed,
334 };
335 
336 static const struct udevice_id ihs_i2c_ids[] = {
337 	{ .compatible = "gdsys,ihs_i2cmaster", },
338 	{ /* sentinel */ }
339 };
340 
341 U_BOOT_DRIVER(i2c_ihs) = {
342 	.name = "i2c_ihs",
343 	.id = UCLASS_I2C,
344 	.of_match = ihs_i2c_ids,
345 	.probe = ihs_i2c_probe,
346 	.priv_auto_alloc_size = sizeof(struct ihs_i2c_priv),
347 	.ops = &ihs_i2c_ops,
348 };
349 
350 #else /* CONFIG_DM_I2C */
351 
352 static void ihs_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr)
353 {
354 #ifdef CONFIG_SYS_I2C_INIT_BOARD
355 	/*
356 	 * Call board specific i2c bus reset routine before accessing the
357 	 * environment, which might be in a chip on that bus. For details
358 	 * about this problem see doc/I2C_Edge_Conditions.
359 	 */
360 	i2c_init_board();
361 #endif
362 }
363 
364 static int ihs_i2c_probe(struct i2c_adapter *adap, uchar chip)
365 {
366 	uchar buffer[2];
367 
368 	if (ihs_i2c_transfer(chip, buffer, 0, I2COP_READ, true))
369 		return 1;
370 
371 	return 0;
372 }
373 
374 static int ihs_i2c_read(struct i2c_adapter *adap, uchar chip, uint addr,
375 			int alen, uchar *buffer, int len)
376 {
377 	u8 addr_bytes[4];
378 
379 	put_unaligned_le32(addr, addr_bytes);
380 
381 	return ihs_i2c_access(adap, chip, addr_bytes, alen, buffer, len,
382 			      I2COP_READ);
383 }
384 
385 static int ihs_i2c_write(struct i2c_adapter *adap, uchar chip, uint addr,
386 			 int alen, uchar *buffer, int len)
387 {
388 	u8 addr_bytes[4];
389 
390 	put_unaligned_le32(addr, addr_bytes);
391 
392 	return ihs_i2c_access(adap, chip, addr_bytes, alen, buffer, len,
393 			      I2COP_WRITE);
394 }
395 
396 static unsigned int ihs_i2c_set_bus_speed(struct i2c_adapter *adap,
397 					  unsigned int speed)
398 {
399 	if (speed != adap->speed)
400 		return 1;
401 	return speed;
402 }
403 
404 /*
405  * Register IHS i2c adapters
406  */
407 #ifdef CONFIG_SYS_I2C_IHS_CH0
408 U_BOOT_I2C_ADAP_COMPLETE(ihs0, ihs_i2c_init, ihs_i2c_probe,
409 			 ihs_i2c_read, ihs_i2c_write,
410 			 ihs_i2c_set_bus_speed,
411 			 CONFIG_SYS_I2C_IHS_SPEED_0,
412 			 CONFIG_SYS_I2C_IHS_SLAVE_0, 0)
413 #ifdef CONFIG_SYS_I2C_IHS_DUAL
414 U_BOOT_I2C_ADAP_COMPLETE(ihs0_1, ihs_i2c_init, ihs_i2c_probe,
415 			 ihs_i2c_read, ihs_i2c_write,
416 			 ihs_i2c_set_bus_speed,
417 			 CONFIG_SYS_I2C_IHS_SPEED_0_1,
418 			 CONFIG_SYS_I2C_IHS_SLAVE_0_1, 16)
419 #endif
420 #endif
421 #ifdef CONFIG_SYS_I2C_IHS_CH1
422 U_BOOT_I2C_ADAP_COMPLETE(ihs1, ihs_i2c_init, ihs_i2c_probe,
423 			 ihs_i2c_read, ihs_i2c_write,
424 			 ihs_i2c_set_bus_speed,
425 			 CONFIG_SYS_I2C_IHS_SPEED_1,
426 			 CONFIG_SYS_I2C_IHS_SLAVE_1, 1)
427 #ifdef CONFIG_SYS_I2C_IHS_DUAL
428 U_BOOT_I2C_ADAP_COMPLETE(ihs1_1, ihs_i2c_init, ihs_i2c_probe,
429 			 ihs_i2c_read, ihs_i2c_write,
430 			 ihs_i2c_set_bus_speed,
431 			 CONFIG_SYS_I2C_IHS_SPEED_1_1,
432 			 CONFIG_SYS_I2C_IHS_SLAVE_1_1, 17)
433 #endif
434 #endif
435 #ifdef CONFIG_SYS_I2C_IHS_CH2
436 U_BOOT_I2C_ADAP_COMPLETE(ihs2, ihs_i2c_init, ihs_i2c_probe,
437 			 ihs_i2c_read, ihs_i2c_write,
438 			 ihs_i2c_set_bus_speed,
439 			 CONFIG_SYS_I2C_IHS_SPEED_2,
440 			 CONFIG_SYS_I2C_IHS_SLAVE_2, 2)
441 #ifdef CONFIG_SYS_I2C_IHS_DUAL
442 U_BOOT_I2C_ADAP_COMPLETE(ihs2_1, ihs_i2c_init, ihs_i2c_probe,
443 			 ihs_i2c_read, ihs_i2c_write,
444 			 ihs_i2c_set_bus_speed,
445 			 CONFIG_SYS_I2C_IHS_SPEED_2_1,
446 			 CONFIG_SYS_I2C_IHS_SLAVE_2_1, 18)
447 #endif
448 #endif
449 #ifdef CONFIG_SYS_I2C_IHS_CH3
450 U_BOOT_I2C_ADAP_COMPLETE(ihs3, ihs_i2c_init, ihs_i2c_probe,
451 			 ihs_i2c_read, ihs_i2c_write,
452 			 ihs_i2c_set_bus_speed,
453 			 CONFIG_SYS_I2C_IHS_SPEED_3,
454 			 CONFIG_SYS_I2C_IHS_SLAVE_3, 3)
455 #ifdef CONFIG_SYS_I2C_IHS_DUAL
456 U_BOOT_I2C_ADAP_COMPLETE(ihs3_1, ihs_i2c_init, ihs_i2c_probe,
457 			 ihs_i2c_read, ihs_i2c_write,
458 			 ihs_i2c_set_bus_speed,
459 			 CONFIG_SYS_I2C_IHS_SPEED_3_1,
460 			 CONFIG_SYS_I2C_IHS_SLAVE_3_1, 19)
461 #endif
462 #endif
463 #endif /* CONFIG_DM_I2C */
464