1 // SPDX-License-Identifier: GPL-2.0-or-later
3  * i2c-algo-pcf.c i2c driver algorithms for PCF8584 adapters
5  *   Copyright (C) 1995-1997 Simon G. Vogl
6  *		   1998-2000 Hans Berglund
10  * <mbailey@littlefeet-inc.com>
21 #include <linux/i2c-algo-pcf.h>
22 #include "i2c-algo-pcf.h"
38 #define set_pcf(adap, ctl, val) adap->setpcf(adap->data, ctl, val)
39 #define get_pcf(adap, ctl) adap->getpcf(adap->data, ctl)
40 #define get_own(adap) adap->getown(adap->data)
41 #define get_clock(adap) adap->getclock(adap->data)
42 #define i2c_outb(adap, val) adap->setpcf(adap->data, 0, val)
43 #define i2c_inb(adap) adap->getpcf(adap->data, 0)
68 		"i2c-algo-pcf.o: lost arbitration (CSR 0x%02x)\n",  in handle_lab()
71 	 * Cleanup from LAB -- reset and enable ESO.  in handle_lab()
79 	 * We pause for a time period sufficient for any running  in handle_lab()
80 	 * I2C transaction to complete -- the arbitration logic won't  in handle_lab()
87 	if (adap->lab_mdelay)  in handle_lab()
88 		mdelay(adap->lab_mdelay);  in handle_lab()
91 		"i2c-algo-pcf.o: reset LAB condition (CSR 0x%02x)\n",  in handle_lab()
103 	while (!(status & I2C_PCF_BB) && --timeout) {  in wait_for_bb()
104 		udelay(100); /* wait for 100 us */  in wait_for_bb()
109 		printk(KERN_ERR "Timeout waiting for Bus Busy\n");  in wait_for_bb()
110 		return -ETIMEDOUT;  in wait_for_bb()
123 	while ((*status & I2C_PCF_PIN) && --timeout) {  in wait_for_pin()
124 		adap->waitforpin(adap->data);  in wait_for_pin()
129 		return -EINTR;  in wait_for_pin()
133 		return -ETIMEDOUT;  in wait_for_pin()
141  * There should be a 30 clock cycle wait after reset, I assume this
144  * to synchronize the BB-bit (in multimaster systems). How long is
145  * this? I assume 1 second is always long enough.
147  * vdovikin: added detect code for PCF8584
153 	DEB3(printk(KERN_DEBUG "i2c-algo-pcf.o: PCF state 0x%02x\n",  in pcf_init_8584()
159 	 * check to see S1 now used as R/W ctrl -  in pcf_init_8584()
163 …DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't select S0 (0x%02x).\n", temp));  in pcf_init_8584()
164 		return -ENXIO; /* definitely not PCF8584 */  in pcf_init_8584()
171 		DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't set S0 (0x%02x).\n", temp));  in pcf_init_8584()
172 		return -ENXIO;  in pcf_init_8584()
179 …DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't select S2 (0x%02x).\n", temp));  in pcf_init_8584()
180 		return -ENXIO;  in pcf_init_8584()
187 		DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't set S2 (0x%02x).\n", temp));  in pcf_init_8584()
188 		return -ENXIO;  in pcf_init_8584()
196 …DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't select S1` (0x%02x).\n", temp)…  in pcf_init_8584()
197 		return -ENXIO;  in pcf_init_8584()
200 	printk(KERN_DEBUG "i2c-algo-pcf.o: detected and initialized PCF8584.\n");  in pcf_init_8584()
208 	struct i2c_algo_pcf_data *adap = i2c_adap->algo_data;  in pcf_sendbytes()
211 	for (wrcount=0; wrcount<count; ++wrcount) {  in pcf_sendbytes()
212 		DEB2(dev_dbg(&i2c_adap->dev, "i2c_write: writing %2.2X\n",  in pcf_sendbytes()
217 			if (timeout == -EINTR)  in pcf_sendbytes()
218 				return -EINTR; /* arbitration lost */  in pcf_sendbytes()
221 			dev_err(&i2c_adap->dev, "i2c_write: error - timeout.\n");  in pcf_sendbytes()
222 			return -EREMOTEIO; /* got a better one ?? */  in pcf_sendbytes()
226 			dev_err(&i2c_adap->dev, "i2c_write: error - no ack.\n");  in pcf_sendbytes()
227 			return -EREMOTEIO; /* got a better one ?? */  in pcf_sendbytes()
242 	struct i2c_algo_pcf_data *adap = i2c_adap->algo_data;  in pcf_readbytes()
245 	/* increment number of bytes to read by one -- read dummy byte */  in pcf_readbytes()
246 	for (i = 0; i <= count; i++) {  in pcf_readbytes()
249 			if (wfp == -EINTR)  in pcf_readbytes()
250 				return -EINTR; /* arbitration lost */  in pcf_readbytes()
253 			dev_err(&i2c_adap->dev, "pcf_readbytes timed out.\n");  in pcf_readbytes()
254 			return -1;  in pcf_readbytes()
259 			dev_err(&i2c_adap->dev, "i2c_read: i2c_inb, No ack.\n");  in pcf_readbytes()
260 			return -1;  in pcf_readbytes()
263 		if (i == count - 1) {  in pcf_readbytes()
273 			buf[i - 1] = i2c_inb(adap);  in pcf_readbytes()
278 	return i - 1;  in pcf_readbytes()
287 	if (msg->flags & I2C_M_REV_DIR_ADDR)  in pcf_doAddress()
298 	struct i2c_algo_pcf_data *adap = i2c_adap->algo_data;  in pcf_xfer()
303 	if (adap->xfer_begin)  in pcf_xfer()
304 		adap->xfer_begin(adap->data);  in pcf_xfer()
306 	/* Check for bus busy */  in pcf_xfer()
309 		DEB2(printk(KERN_ERR "i2c-algo-pcf.o: "  in pcf_xfer()
310 			    "Timeout waiting for BB in pcf_xfer\n");)  in pcf_xfer()
311 		i = -EIO;  in pcf_xfer()
315 	for (i = 0;ret >= 0 && i < num; i++) {  in pcf_xfer()
318 		DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: Doing %s %d bytes to 0x%02x - %d of %d messages\n",  in pcf_xfer()
319 		     pmsg->flags & I2C_M_RD ? "read" : "write",  in pcf_xfer()
320 		     pmsg->len, pmsg->addr, i + 1, num);)  in pcf_xfer()
328 		/* Wait for PIN (pending interrupt NOT) */  in pcf_xfer()
331 			if (timeout == -EINTR) {  in pcf_xfer()
333 				i = -EINTR;  in pcf_xfer()
337 			DEB2(printk(KERN_ERR "i2c-algo-pcf.o: Timeout waiting "  in pcf_xfer()
338 				    "for PIN(1) in pcf_xfer\n");)  in pcf_xfer()
339 			i = -EREMOTEIO;  in pcf_xfer()
343 		/* Check LRB (last rcvd bit - slave ack) */  in pcf_xfer()
346 			DEB2(printk(KERN_ERR "i2c-algo-pcf.o: No LRB(1) in pcf_xfer\n");)  in pcf_xfer()
347 			i = -EREMOTEIO;  in pcf_xfer()
351 		DEB3(printk(KERN_DEBUG "i2c-algo-pcf.o: Msg %d, addr=0x%x, flags=0x%x, len=%d\n",  in pcf_xfer()
354 		if (pmsg->flags & I2C_M_RD) {  in pcf_xfer()
355 			ret = pcf_readbytes(i2c_adap, pmsg->buf, pmsg->len,  in pcf_xfer()
358 			if (ret != pmsg->len) {  in pcf_xfer()
359 				DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: fail: "  in pcf_xfer()
362 				DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: read %d bytes.\n",ret));  in pcf_xfer()
365 			ret = pcf_sendbytes(i2c_adap, pmsg->buf, pmsg->len,  in pcf_xfer()
368 			if (ret != pmsg->len) {  in pcf_xfer()
369 				DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: fail: "  in pcf_xfer()
372 				DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: wrote %d bytes.\n",ret));  in pcf_xfer()
378 	if (adap->xfer_end)  in pcf_xfer()
379 		adap->xfer_end(adap->data);  in pcf_xfer()
400 	struct i2c_algo_pcf_data *pcf_adap = adap->algo_data;  in i2c_pcf_add_bus()
403 	DEB2(dev_dbg(&adap->dev, "hw routines registered.\n"));  in i2c_pcf_add_bus()
406 	adap->algo = &pcf_algo;  in i2c_pcf_add_bus()
418 MODULE_DESCRIPTION("I2C-Bus PCF8584 algorithm");
423 	"debug level - 0 off; 1 normal; 2,3 more verbose; 9 pcf-protocol");