1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
|
/*
* Copyright (C) 2012 Boundary Devices Inc.
*
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <common.h>
#include <asm/arch/clock.h>
#include <asm/arch/imx-regs.h>
#include <asm/errno.h>
#include <asm/gpio.h>
#include <asm/imx-common/mxc_i2c.h>
#include <watchdog.h>
static int force_idle_bus(void *priv)
{
int i;
int sda, scl;
ulong elapsed, start_time;
struct i2c_pads_info *p = (struct i2c_pads_info *)priv;
int ret = 0;
gpio_direction_input(p->sda.gp);
gpio_direction_input(p->scl.gp);
imx_iomux_v3_setup_pad(p->sda.gpio_mode);
imx_iomux_v3_setup_pad(p->scl.gpio_mode);
sda = gpio_get_value(p->sda.gp);
scl = gpio_get_value(p->scl.gp);
if ((sda & scl) == 1)
goto exit; /* Bus is idle already */
printf("%s: sda=%d scl=%d sda.gp=0x%x scl.gp=0x%x\n", __func__,
sda, scl, p->sda.gp, p->scl.gp);
/* Send high and low on the SCL line */
for (i = 0; i < 9; i++) {
gpio_direction_output(p->scl.gp, 0);
udelay(50);
gpio_direction_input(p->scl.gp);
udelay(50);
}
start_time = get_timer(0);
for (;;) {
sda = gpio_get_value(p->sda.gp);
scl = gpio_get_value(p->scl.gp);
if ((sda & scl) == 1)
break;
WATCHDOG_RESET();
elapsed = get_timer(start_time);
if (elapsed > (CONFIG_SYS_HZ / 5)) { /* .2 seconds */
ret = -EBUSY;
printf("%s: failed to clear bus, sda=%d scl=%d\n",
__func__, sda, scl);
break;
}
}
exit:
imx_iomux_v3_setup_pad(p->sda.i2c_mode);
imx_iomux_v3_setup_pad(p->scl.i2c_mode);
return ret;
}
static void * const i2c_bases[] = {
(void *)I2C1_BASE_ADDR,
(void *)I2C2_BASE_ADDR,
#ifdef I2C3_BASE_ADDR
(void *)I2C3_BASE_ADDR,
#endif
};
/* i2c_index can be from 0 - 2 */
void setup_i2c(unsigned i2c_index, int speed, int slave_addr,
struct i2c_pads_info *p)
{
if (i2c_index >= ARRAY_SIZE(i2c_bases))
return;
/* Enable i2c clock */
enable_i2c_clk(1, i2c_index);
/* Make sure bus is idle */
force_idle_bus(p);
bus_i2c_init(i2c_bases[i2c_index], speed, slave_addr,
force_idle_bus, p);
}
|
