xref: /openbmc/u-boot/board/keymile/km83xx/km83xx_i2c.c (revision e792affe21686788ee7fdbabbb5fc1bcc799eaa8)
1*e792affeSHolger Brunck /*
2*e792affeSHolger Brunck  * (C) Copyright 2011
3*e792affeSHolger Brunck  * Holger Brunck, Keymile GmbH Hannover, holger.brunck@keymile.com
4*e792affeSHolger Brunck  *
5*e792affeSHolger Brunck  * See file CREDITS for list of people who contributed to this
6*e792affeSHolger Brunck  * project.
7*e792affeSHolger Brunck  *
8*e792affeSHolger Brunck  * This program is free software; you can redistribute it and/or
9*e792affeSHolger Brunck  * modify it under the terms of the GNU General Public License as
10*e792affeSHolger Brunck  * published by the Free Software Foundation; either version 2 of
11*e792affeSHolger Brunck  * the License, or (at your option) any later version.
12*e792affeSHolger Brunck  *
13*e792affeSHolger Brunck  * This program is distributed in the hope that it will be useful,
14*e792affeSHolger Brunck  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15*e792affeSHolger Brunck  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16*e792affeSHolger Brunck  * GNU General Public License for more details.
17*e792affeSHolger Brunck  *
18*e792affeSHolger Brunck  * You should have received a copy of the GNU General Public License
19*e792affeSHolger Brunck  * along with this program; if not, write to the Free Software
20*e792affeSHolger Brunck  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
21*e792affeSHolger Brunck  * MA 02111-1307 USA
22*e792affeSHolger Brunck  */
23*e792affeSHolger Brunck 
24*e792affeSHolger Brunck #include <common.h>
25*e792affeSHolger Brunck #include <i2c.h>
26*e792affeSHolger Brunck #include <asm/io.h>
27*e792affeSHolger Brunck #include <linux/ctype.h>
28*e792affeSHolger Brunck #include "../common/common.h"
29*e792affeSHolger Brunck 
30*e792affeSHolger Brunck static void i2c_write_start_seq(void)
31*e792affeSHolger Brunck {
32*e792affeSHolger Brunck 	struct fsl_i2c *dev;
33*e792affeSHolger Brunck 	dev = (struct fsl_i2c *) (CONFIG_SYS_IMMR + CONFIG_SYS_I2C_OFFSET);
34*e792affeSHolger Brunck 	udelay(DELAY_ABORT_SEQ);
35*e792affeSHolger Brunck 	out_8(&dev->cr, (I2C_CR_MEN | I2C_CR_MSTA));
36*e792affeSHolger Brunck 	udelay(DELAY_ABORT_SEQ);
37*e792affeSHolger Brunck 	out_8(&dev->cr, (I2C_CR_MEN));
38*e792affeSHolger Brunck }
39*e792affeSHolger Brunck 
40*e792affeSHolger Brunck int i2c_make_abort(void)
41*e792affeSHolger Brunck {
42*e792affeSHolger Brunck 	struct fsl_i2c *dev;
43*e792affeSHolger Brunck 	dev = (struct fsl_i2c *) (CONFIG_SYS_IMMR + CONFIG_SYS_I2C_OFFSET);
44*e792affeSHolger Brunck 	uchar	dummy;
45*e792affeSHolger Brunck 	uchar   last;
46*e792affeSHolger Brunck 	int     nbr_read = 0;
47*e792affeSHolger Brunck 	int     i = 0;
48*e792affeSHolger Brunck 	int	    ret = 0;
49*e792affeSHolger Brunck 
50*e792affeSHolger Brunck 	/* wait after each operation to finsh with a delay */
51*e792affeSHolger Brunck 	out_8(&dev->cr, (I2C_CR_MSTA));
52*e792affeSHolger Brunck 	udelay(DELAY_ABORT_SEQ);
53*e792affeSHolger Brunck 	out_8(&dev->cr, (I2C_CR_MEN | I2C_CR_MSTA));
54*e792affeSHolger Brunck 	udelay(DELAY_ABORT_SEQ);
55*e792affeSHolger Brunck 	dummy = in_8(&dev->dr);
56*e792affeSHolger Brunck 	udelay(DELAY_ABORT_SEQ);
57*e792affeSHolger Brunck 	last = in_8(&dev->dr);
58*e792affeSHolger Brunck 	nbr_read++;
59*e792affeSHolger Brunck 
60*e792affeSHolger Brunck 	/*
61*e792affeSHolger Brunck 	 * do read until the last bit is 1, but stop if the full eeprom is
62*e792affeSHolger Brunck 	 * read.
63*e792affeSHolger Brunck 	 */
64*e792affeSHolger Brunck 	while (((last & 0x01) != 0x01) &&
65*e792affeSHolger Brunck 		(nbr_read < CONFIG_SYS_IVM_EEPROM_MAX_LEN)) {
66*e792affeSHolger Brunck 		udelay(DELAY_ABORT_SEQ);
67*e792affeSHolger Brunck 		last = in_8(&dev->dr);
68*e792affeSHolger Brunck 		nbr_read++;
69*e792affeSHolger Brunck 	}
70*e792affeSHolger Brunck 	if ((last & 0x01) != 0x01)
71*e792affeSHolger Brunck 		ret = -2;
72*e792affeSHolger Brunck 	if ((last != 0xff) || (nbr_read > 1))
73*e792affeSHolger Brunck 		printf("[INFO] i2c abort after %d bytes (0x%02x)\n",
74*e792affeSHolger Brunck 			nbr_read, last);
75*e792affeSHolger Brunck 	udelay(DELAY_ABORT_SEQ);
76*e792affeSHolger Brunck 	out_8(&dev->cr, (I2C_CR_MEN));
77*e792affeSHolger Brunck 	udelay(DELAY_ABORT_SEQ);
78*e792affeSHolger Brunck 	/* clear status reg */
79*e792affeSHolger Brunck 	out_8(&dev->sr, 0);
80*e792affeSHolger Brunck 
81*e792affeSHolger Brunck 	for (i = 0; i < 5; i++)
82*e792affeSHolger Brunck 		i2c_write_start_seq();
83*e792affeSHolger Brunck 	if (ret != 0)
84*e792affeSHolger Brunck 		printf("[ERROR] i2c abort failed after %d bytes (0x%02x)\n",
85*e792affeSHolger Brunck 			nbr_read, last);
86*e792affeSHolger Brunck 
87*e792affeSHolger Brunck 	return ret;
88*e792affeSHolger Brunck }
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