2 -------------------------------------------------------------------------
3 i2c-algo-ite.c i2c driver algorithms for ITE adapters
5 Hai-Pao Fan, MontaVista Software, Inc.
6 hpfan@mvista.com or source@mvista.com
8 Copyright 2000 MontaVista Software Inc.
10 ---------------------------------------------------------------------------
11 This file was highly leveraged from i2c-algo-pcf.c, which was created
12 by Simon G. Vogl and Hans Berglund:
15 Copyright (C) 1995-1997 Simon G. Vogl
16 1998-2000 Hans Berglund
18 This program is free software; you can redistribute it and/or modify
19 it under the terms of the GNU General Public License as published by
20 the Free Software Foundation; either version 2 of the License, or
21 (at your option) any later version.
23 This program is distributed in the hope that it will be useful,
24 but WITHOUT ANY WARRANTY; without even the implied warranty of
25 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
26 GNU General Public License for more details.
28 You should have received a copy of the GNU General Public License
29 along with this program; if not, write to the Free Software
30 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
31 /* ------------------------------------------------------------------------- */
33 /* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and
34 Frodo Looijaard <frodol@dds.nl> ,and also from Martin Bailey
35 <mbailey@littlefeet-inc.com> */
37 #include <linux/kernel.h>
38 #include <linux/module.h>
39 #include <linux/delay.h>
40 #include <linux/slab.h>
41 #include <linux/init.h>
42 #include <asm/uaccess.h>
43 #include <linux/ioport.h>
44 #include <linux/errno.h>
45 #include <linux/sched.h>
47 #include <linux/i2c.h>
48 #include <linux/i2c-algo-ite.h>
49 #include "i2c-algo-ite.h"
51 #define PM_DSR IT8172_PCI_IO_BASE + IT_PM_DSR
52 #define PM_IBSR IT8172_PCI_IO_BASE + IT_PM_DSR + 0x04
53 #define GPIO_CCR IT8172_PCI_IO_BASE + IT_GPCCR
55 #define DEB2(x) if (i2c_debug>=2) x
56 #define DEB3(x) if (i2c_debug>=3) x /* print several statistical values*/
57 #define DEF_TIMEOUT 16
63 static int iic_test; /* see if the line-setting functions work */
65 /* --- setting states on the bus with the right timing: --------------- */
67 #define get_clock(adap) adap->getclock(adap->data)
68 #define iic_outw(adap, reg, val) adap->setiic(adap->data, reg, val)
69 #define iic_inw(adap, reg) adap->getiic(adap->data, reg)
72 /* --- other auxiliary functions -------------------------------------- */
74 static void iic_start(struct i2c_algo_iic_data *adap)
76 iic_outw(adap,ITE_I2CHCR,ITE_CMD);
79 static void iic_stop(struct i2c_algo_iic_data *adap)
81 iic_outw(adap,ITE_I2CHCR,0);
82 iic_outw(adap,ITE_I2CHSR,ITE_I2CHSR_TDI);
85 static void iic_reset(struct i2c_algo_iic_data *adap)
87 iic_outw(adap, PM_IBSR, iic_inw(adap, PM_IBSR) | 0x80);
91 static int wait_for_bb(struct i2c_algo_iic_data *adap)
93 int timeout = DEF_TIMEOUT;
96 status = iic_inw(adap, ITE_I2CHSR);
98 while (timeout-- && (status & ITE_I2CHSR_HB)) {
99 udelay(1000); /* How much is this? */
100 status = iic_inw(adap, ITE_I2CHSR);
104 printk(KERN_ERR "Timeout, host is busy\n");
110 /* After we issue a transaction on the IIC bus, this function
111 * is called. It puts this process to sleep until we get an interrupt from
112 * from the controller telling us that the transaction we requested in complete.
114 static int wait_for_pin(struct i2c_algo_iic_data *adap, short *status) {
116 int timeout = DEF_TIMEOUT;
118 timeout = wait_for_bb(adap);
120 DEB2(printk("Timeout waiting for host not busy\n");)
123 timeout = DEF_TIMEOUT;
125 *status = iic_inw(adap, ITE_I2CHSR);
127 while (timeout-- && !(*status & ITE_I2CHSR_TDI)) {
129 *status = iic_inw(adap, ITE_I2CHSR);
138 static int wait_for_fe(struct i2c_algo_iic_data *adap, short *status)
140 int timeout = DEF_TIMEOUT;
142 *status = iic_inw(adap, ITE_I2CFSR);
144 while (timeout-- && (*status & ITE_I2CFSR_FE)) {
146 iic_inw(adap, ITE_I2CFSR);
155 static int iic_init (struct i2c_algo_iic_data *adap)
159 /* Clear bit 7 to set I2C to normal operation mode */
160 i=iic_inw(adap, PM_DSR)& 0xff7f;
161 iic_outw(adap, PM_DSR, i);
163 /* set IT_GPCCR port C bit 2&3 as function 2 */
164 i = iic_inw(adap, GPIO_CCR) & 0xfc0f;
165 iic_outw(adap,GPIO_CCR,i);
167 /* Clear slave address/sub-address */
168 iic_outw(adap,ITE_I2CSAR, 0);
169 iic_outw(adap,ITE_I2CSSAR, 0);
171 /* Set clock counter register */
172 iic_outw(adap,ITE_I2CCKCNT, get_clock(adap));
174 /* Set START/reSTART/STOP time registers */
175 iic_outw(adap,ITE_I2CSHDR, 0x0a);
176 iic_outw(adap,ITE_I2CRSUR, 0x0a);
177 iic_outw(adap,ITE_I2CPSUR, 0x0a);
179 /* Enable interrupts on completing the current transaction */
180 iic_outw(adap,ITE_I2CHCR, ITE_I2CHCR_IE | ITE_I2CHCR_HCE);
182 /* Clear transfer count */
183 iic_outw(adap,ITE_I2CFBCR, 0x0);
185 DEB2(printk("iic_init: Initialized IIC on ITE 0x%x\n",
186 iic_inw(adap, ITE_I2CHSR)));
192 * Sanity check for the adapter hardware - check the reaction of
193 * the bus lines only if it seems to be idle.
195 static int test_bus(struct i2c_algo_iic_data *adap, char *name) {
199 if (adap->getscl==NULL) {
200 printk("test_bus: Warning: Adapter can't read from clock line - skipping test.\n");
204 printk("test_bus: Adapter: %s scl: %d sda: %d -- testing...\n",
205 name,getscl(adap),getsda(adap));
207 printk("test_bus: %s seems to be busy.\n",adap->name);
211 printk("test_bus:1 scl: %d sda: %d\n", getscl(adap),
213 if ( 0 != getsda(adap) ) {
214 printk("test_bus: %s SDA stuck high!\n",name);
218 if ( 0 == getscl(adap) ) {
219 printk("test_bus: %s SCL unexpected low while pulling SDA low!\n",
224 printk("test_bus:2 scl: %d sda: %d\n", getscl(adap),
226 if ( 0 == getsda(adap) ) {
227 printk("test_bus: %s SDA stuck low!\n",name);
231 if ( 0 == getscl(adap) ) {
232 printk("test_bus: %s SCL unexpected low while SDA high!\n",
237 printk("test_bus:3 scl: %d sda: %d\n", getscl(adap),
239 if ( 0 != getscl(adap) ) {
244 if ( 0 == getsda(adap) ) {
245 printk("test_bus: %s SDA unexpected low while pulling SCL low!\n",
250 printk("test_bus:4 scl: %d sda: %d\n", getscl(adap),
252 if ( 0 == getscl(adap) ) {
253 printk("test_bus: %s SCL stuck low!\n",name);
257 if ( 0 == getsda(adap) ) {
258 printk("test_bus: %s SDA unexpected low while SCL high!\n",
262 printk("test_bus: %s passed test.\n",name);
272 /* ----- Utility functions
276 /* Verify the device we want to talk to on the IIC bus really exists. */
277 static inline int try_address(struct i2c_algo_iic_data *adap,
278 unsigned int addr, int retries)
283 for (i=0;i<retries;i++) {
284 iic_outw(adap, ITE_I2CSAR, addr);
286 if (wait_for_pin(adap, &status) == 0) {
287 if ((status & ITE_I2CHSR_DNE) == 0) {
289 iic_outw(adap, ITE_I2CFCR, ITE_I2CFCR_FLUSH);
291 break; /* success! */
295 udelay(adap->udelay);
297 DEB2(if (i) printk("try_address: needed %d retries for 0x%x\n",i,
303 static int iic_sendbytes(struct i2c_adapter *i2c_adap,const char *buf,
306 struct i2c_algo_iic_data *adap = i2c_adap->algo_data;
307 int wrcount=0, timeout;
309 int loops, remainder, i, j;
315 iic_outw(adap, ITE_I2CSSAR, (unsigned short)buf[wrcount++]);
320 loops = count / 32; /* 32-byte FIFO */
321 remainder = count % 32;
324 for(i=0; i<loops; i++) {
326 iic_outw(adap, ITE_I2CFBCR, 32);
327 for(j=0; j<32/2; j++) {
328 tmp.byte[1] = buf[wrcount++];
329 tmp.byte[0] = buf[wrcount++];
330 iic_outw(adap, ITE_I2CFDR, tmp.word);
333 /* status FIFO overrun */
334 iic_inw(adap, ITE_I2CFSR);
335 iic_inw(adap, ITE_I2CFBCR);
337 iic_outw(adap, ITE_I2CHCR, ITE_WRITE); /* Issue WRITE command */
339 /* Wait for transmission to complete */
340 timeout = wait_for_pin(adap, &status);
343 printk("iic_sendbytes: %s write timeout.\n", i2c_adap->name);
344 return -EREMOTEIO; /* got a better one ?? */
346 if (status & ITE_I2CHSR_DB) {
348 printk("iic_sendbytes: %s write error - no ack.\n", i2c_adap->name);
349 return -EREMOTEIO; /* got a better one ?? */
354 iic_outw(adap, ITE_I2CFBCR, remainder);
355 for(i=0; i<remainder/2; i++) {
356 tmp.byte[1] = buf[wrcount++];
357 tmp.byte[0] = buf[wrcount++];
358 iic_outw(adap, ITE_I2CFDR, tmp.word);
361 /* status FIFO overrun */
362 iic_inw(adap, ITE_I2CFSR);
363 iic_inw(adap, ITE_I2CFBCR);
365 iic_outw(adap, ITE_I2CHCR, ITE_WRITE); /* Issue WRITE command */
367 timeout = wait_for_pin(adap, &status);
370 printk("iic_sendbytes: %s write timeout.\n", i2c_adap->name);
371 return -EREMOTEIO; /* got a better one ?? */
374 if (status & ITE_I2CHSR_DB) {
376 printk("iic_sendbytes: %s write error - no ack.\n", i2c_adap->name);
377 return -EREMOTEIO; /* got a better one ?? */
386 static int iic_readbytes(struct i2c_adapter *i2c_adap, char *buf, int count,
389 int rdcount=0, i, timeout;
391 struct i2c_algo_iic_data *adap = i2c_adap->algo_data;
392 int loops, remainder, j;
398 loops = count / 32; /* 32-byte FIFO */
399 remainder = count % 32;
402 for(i=0; i<loops; i++) {
403 iic_outw(adap, ITE_I2CFBCR, 32);
405 iic_outw(adap, ITE_I2CHCR, ITE_SREAD);
407 iic_outw(adap, ITE_I2CHCR, ITE_READ); /* Issue READ command */
409 timeout = wait_for_pin(adap, &status);
412 printk("iic_readbytes: %s read timeout.\n", i2c_adap->name);
416 if (status & ITE_I2CHSR_DB) {
418 printk("iic_readbytes: %s read error - no ack.\n", i2c_adap->name);
423 timeout = wait_for_fe(adap, &status);
426 printk("iic_readbytes: %s FIFO is empty\n", i2c_adap->name);
430 for(j=0; j<32/2; j++) {
431 tmp.word = iic_inw(adap, ITE_I2CFDR);
432 buf[rdcount++] = tmp.byte[1];
433 buf[rdcount++] = tmp.byte[0];
436 /* status FIFO underrun */
437 iic_inw(adap, ITE_I2CFSR);
444 remainder=(remainder+1)/2 * 2;
445 iic_outw(adap, ITE_I2CFBCR, remainder);
447 iic_outw(adap, ITE_I2CHCR, ITE_SREAD);
449 iic_outw(adap, ITE_I2CHCR, ITE_READ); /* Issue READ command */
451 timeout = wait_for_pin(adap, &status);
454 printk("iic_readbytes: %s read timeout.\n", i2c_adap->name);
458 if (status & ITE_I2CHSR_DB) {
460 printk("iic_readbytes: %s read error - no ack.\n", i2c_adap->name);
464 timeout = wait_for_fe(adap, &status);
467 printk("iic_readbytes: %s FIFO is empty\n", i2c_adap->name);
471 for(i=0; i<(remainder+1)/2; i++) {
472 tmp.word = iic_inw(adap, ITE_I2CFDR);
473 buf[rdcount++] = tmp.byte[1];
474 buf[rdcount++] = tmp.byte[0];
477 /* status FIFO underrun */
478 iic_inw(adap, ITE_I2CFSR);
487 /* This function implements combined transactions. Combined
488 * transactions consist of combinations of reading and writing blocks of data.
489 * Each transfer (i.e. a read or a write) is separated by a repeated start
493 static int iic_combined_transaction(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num)
496 struct i2c_msg *pmsg;
499 DEB2(printk("Beginning combined transaction\n"));
501 for(i=0; i<(num-1); i++) {
503 if(pmsg->flags & I2C_M_RD) {
504 DEB2(printk(" This one is a read\n"));
505 ret = iic_readbytes(i2c_adap, pmsg->buf, pmsg->len, IIC_COMBINED_XFER);
507 else if(!(pmsg->flags & I2C_M_RD)) {
508 DEB2(printk("This one is a write\n"));
509 ret = iic_sendbytes(i2c_adap, pmsg->buf, pmsg->len, IIC_COMBINED_XFER);
512 /* Last read or write segment needs to be terminated with a stop */
515 if(pmsg->flags & I2C_M_RD) {
516 DEB2(printk("Doing the last read\n"));
517 ret = iic_readbytes(i2c_adap, pmsg->buf, pmsg->len, IIC_SINGLE_XFER);
519 else if(!(pmsg->flags & I2C_M_RD)) {
520 DEB2(printk("Doing the last write\n"));
521 ret = iic_sendbytes(i2c_adap, pmsg->buf, pmsg->len, IIC_SINGLE_XFER);
529 /* Whenever we initiate a transaction, the first byte clocked
530 * onto the bus after the start condition is the address (7 bit) of the
531 * device we want to talk to. This function manipulates the address specified
532 * so that it makes sense to the hardware when written to the IIC peripheral.
534 * Note: 10 bit addresses are not supported in this driver, although they are
535 * supported by the hardware. This functionality needs to be implemented.
537 static inline int iic_doAddress(struct i2c_algo_iic_data *adap,
538 struct i2c_msg *msg, int retries)
540 unsigned short flags = msg->flags;
544 /* Ten bit addresses not supported right now */
545 if ( (flags & I2C_M_TEN) ) {
547 addr = 0xf0 | (( msg->addr >> 7) & 0x03);
548 DEB2(printk("addr0: %d\n",addr));
549 ret = try_address(adap, addr, retries);
551 printk("iic_doAddress: died at extended address code.\n");
554 iic_outw(adap,msg->addr & 0x7f);
556 printk("iic_doAddress: died at 2nd address code.\n");
559 if ( flags & I2C_M_RD ) {
562 ret = try_address(adap, addr, retries);
564 printk("iic_doAddress: died at extended address code.\n");
571 addr = ( msg->addr << 1 );
574 if (flags & I2C_M_RD )
576 if (flags & I2C_M_REV_DIR_ADDR )
580 if (iic_inw(adap, ITE_I2CSAR) != addr) {
581 iic_outw(adap, ITE_I2CSAR, addr);
582 ret = try_address(adap, addr, retries);
584 printk("iic_doAddress: died at address code.\n");
595 /* Description: Prepares the controller for a transaction (clearing status
596 * registers, data buffers, etc), and then calls either iic_readbytes or
597 * iic_sendbytes to do the actual transaction.
599 * still to be done: Before we issue a transaction, we should
600 * verify that the bus is not busy or in some unknown state.
602 static int iic_xfer(struct i2c_adapter *i2c_adap,
603 struct i2c_msg *msgs,
606 struct i2c_algo_iic_data *adap = i2c_adap->algo_data;
607 struct i2c_msg *pmsg;
614 DEB2(printk("iic_xfer: read/write length is 0\n");)
617 if(!(pmsg->flags & I2C_M_RD) && (!(pmsg->len)%2) ) {
618 DEB2(printk("iic_xfer: write buffer length is not odd\n");)
622 /* Wait for any pending transfers to complete */
623 timeout = wait_for_bb(adap);
625 DEB2(printk("iic_xfer: Timeout waiting for host not busy\n");)
630 iic_outw(adap, ITE_I2CFCR, ITE_I2CFCR_FLUSH);
633 ret = iic_doAddress(adap, pmsg, i2c_adap->retries);
638 /* Combined transaction (read and write) */
640 DEB2(printk("iic_xfer: Call combined transaction\n"));
641 ret = iic_combined_transaction(i2c_adap, msgs, num);
645 DEB3(printk("iic_xfer: Msg %d, addr=0x%x, flags=0x%x, len=%d\n",
646 i, msgs[i].addr, msgs[i].flags, msgs[i].len);)
648 if(pmsg->flags & I2C_M_RD) /* Read */
649 ret = iic_readbytes(i2c_adap, pmsg->buf, pmsg->len, 0);
652 ret = iic_sendbytes(i2c_adap, pmsg->buf, pmsg->len);
655 if (ret != pmsg->len)
656 DEB3(printk("iic_xfer: error or fail on read/write %d bytes.\n",ret));
658 DEB3(printk("iic_xfer: read/write %d bytes.\n",ret));
664 /* Implements device specific ioctls. Higher level ioctls can
665 * be found in i2c-core.c and are typical of any i2c controller (specifying
666 * slave address, timeouts, etc). These ioctls take advantage of any hardware
667 * features built into the controller for which this algorithm-adapter set
668 * was written. These ioctls allow you to take control of the data and clock
669 * lines and set the either high or low,
670 * similar to a GPIO pin.
672 static int algo_control(struct i2c_adapter *adapter,
673 unsigned int cmd, unsigned long arg)
676 struct i2c_algo_iic_data *adap = adapter->algo_data;
677 struct i2c_iic_msg s_msg;
681 if (cmd == I2C_SREAD) {
682 if(copy_from_user(&s_msg, (struct i2c_iic_msg *)arg,
683 sizeof(struct i2c_iic_msg)))
685 buf = kmalloc(s_msg.len, GFP_KERNEL);
690 iic_outw(adap, ITE_I2CFCR, ITE_I2CFCR_FLUSH);
693 iic_outw(adap, ITE_I2CSAR,s_msg.addr<<1);
694 iic_outw(adap, ITE_I2CSSAR,s_msg.waddr & 0xff);
696 ret = iic_readbytes(adapter, buf, s_msg.len, 1);
698 if(copy_to_user( s_msg.buf, buf, s_msg.len) )
707 static u32 iic_func(struct i2c_adapter *adap)
709 return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR |
710 I2C_FUNC_PROTOCOL_MANGLING;
713 /* -----exported algorithm data: ------------------------------------- */
715 static struct i2c_algorithm iic_algo = {
716 .master_xfer = iic_xfer,
717 .algo_control = algo_control, /* ioctl */
718 .functionality = iic_func,
723 * registering functions to load algorithms at runtime
725 int i2c_iic_add_bus(struct i2c_adapter *adap)
727 struct i2c_algo_iic_data *iic_adap = adap->algo_data;
730 int ret = test_bus(iic_adap, adap->name);
735 DEB2(printk("i2c-algo-ite: hw routines for %s registered.\n",
738 /* register new adapter to i2c module... */
739 adap->algo = &iic_algo;
741 adap->timeout = 100; /* default values, should */
742 adap->retries = 3; /* be replaced by defines */
746 return i2c_add_adapter(adap);
750 int i2c_iic_del_bus(struct i2c_adapter *adap)
753 if ((res = i2c_del_adapter(adap)) < 0)
755 DEB2(printk("i2c-algo-ite: adapter unregistered: %s\n",adap->name));
761 int __init i2c_algo_iic_init (void)
763 printk(KERN_INFO "ITE iic (i2c) algorithm module\n");
768 void i2c_algo_iic_exit(void)
774 EXPORT_SYMBOL(i2c_iic_add_bus);
775 EXPORT_SYMBOL(i2c_iic_del_bus);
777 /* The MODULE_* macros resolve to nothing if MODULES is not defined
778 * when this file is compiled.
780 MODULE_AUTHOR("MontaVista Software <www.mvista.com>");
781 MODULE_DESCRIPTION("ITE iic algorithm");
782 MODULE_LICENSE("GPL");
784 module_param(iic_test, bool, 0);
785 module_param(i2c_debug, int, S_IRUGO | S_IWUSR);
787 MODULE_PARM_DESC(iic_test, "Test if the I2C bus is available");
788 MODULE_PARM_DESC(i2c_debug,
789 "debug level - 0 off; 1 normal; 2,3 more verbose; 9 iic-protocol");
792 /* This function resolves to init_module (the function invoked when a module
793 * is loaded via insmod) when this file is compiled with MODULES defined.
794 * Otherwise (i.e. if you want this driver statically linked to the kernel),
795 * a pointer to this function is stored in a table and called
796 * during the initialization of the kernel (in do_basic_setup in /init/main.c)
798 * All this functionality is complements of the macros defined in linux/init.h
800 module_init(i2c_algo_iic_init);
803 /* If MODULES is defined when this file is compiled, then this function will
804 * resolved to cleanup_module.
806 module_exit(i2c_algo_iic_exit);