summaryrefslogtreecommitdiff
path: root/arch/arm/plat-omap/i2c.c
blob: be6deb7c12ec8fe9df3bef6315814b6e1206ed68 (plain)
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
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
/*
 * linux/arch/arm/plat-omap/i2c.c
 *
 * Helper module for board specific I2C bus registration
 *
 * Copyright (C) 2007 Nokia Corporation.
 *
 * Contact: Jarkko Nikula <jhnikula@gmail.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 * 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., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 *
 */

#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/i2c.h>
#include <linux/i2c-omap.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/clk.h>

#include <mach/irqs.h>

#include "../mach-omap1/soc.h"
#include "../mach-omap2/soc.h"

#include "i2c.h"

#define OMAP_I2C_MAX_CONTROLLERS 4
static struct omap_i2c_bus_platform_data i2c_pdata[OMAP_I2C_MAX_CONTROLLERS];

#define OMAP_I2C_CMDLINE_SETUP	(BIT(31))

static int __init omap_i2c_nr_ports(void)
{
	int ports = 0;

	if (cpu_class_is_omap1())
		ports = 1;
	else if (cpu_is_omap24xx())
		ports = 2;
	else if (cpu_is_omap34xx())
		ports = 3;
	else if (cpu_is_omap44xx())
		ports = 4;

	return ports;
}

/**
 * omap_i2c_bus_setup - Process command line options for the I2C bus speed
 * @str: String of options
 *
 * This function allow to override the default I2C bus speed for given I2C
 * bus with a command line option.
 *
 * Format: i2c_bus=bus_id,clkrate (in kHz)
 *
 * Returns 1 on success, 0 otherwise.
 */
static int __init omap_i2c_bus_setup(char *str)
{
	int ports;
	int ints[3];

	ports = omap_i2c_nr_ports();
	get_options(str, 3, ints);
	if (ints[0] < 2 || ints[1] < 1 || ints[1] > ports)
		return 0;
	i2c_pdata[ints[1] - 1].clkrate = ints[2];
	i2c_pdata[ints[1] - 1].clkrate |= OMAP_I2C_CMDLINE_SETUP;

	return 1;
}
__setup("i2c_bus=", omap_i2c_bus_setup);

/*
 * Register busses defined in command line but that are not registered with
 * omap_register_i2c_bus from board initialization code.
 */
static int __init omap_register_i2c_bus_cmdline(void)
{
	int i, err = 0;

	for (i = 0; i < ARRAY_SIZE(i2c_pdata); i++)
		if (i2c_pdata[i].clkrate & OMAP_I2C_CMDLINE_SETUP) {
			i2c_pdata[i].clkrate &= ~OMAP_I2C_CMDLINE_SETUP;
			err = omap_i2c_add_bus(&i2c_pdata[i], i + 1);
			if (err)
				goto out;
		}

out:
	return err;
}
subsys_initcall(omap_register_i2c_bus_cmdline);

/**
 * omap_register_i2c_bus - register I2C bus with device descriptors
 * @bus_id: bus id counting from number 1
 * @clkrate: clock rate of the bus in kHz
 * @info: pointer into I2C device descriptor table or NULL
 * @len: number of descriptors in the table
 *
 * Returns 0 on success or an error code.
 */
int __init omap_register_i2c_bus(int bus_id, u32 clkrate,
			  struct i2c_board_info const *info,
			  unsigned len)
{
	int err;

	BUG_ON(bus_id < 1 || bus_id > omap_i2c_nr_ports());

	if (info) {
		err = i2c_register_board_info(bus_id, info, len);
		if (err)
			return err;
	}

	if (!i2c_pdata[bus_id - 1].clkrate)
		i2c_pdata[bus_id - 1].clkrate = clkrate;

	i2c_pdata[bus_id - 1].clkrate &= ~OMAP_I2C_CMDLINE_SETUP;

	return omap_i2c_add_bus(&i2c_pdata[bus_id - 1], bus_id);
}