Blame view

kernel/linux-imx6_3.14.28/arch/arm/plat-omap/i2c.c 3.04 KB
6b13f685e   김민수   BSP 최초 추가
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
  /*
   * 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 <plat/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))
  
  /**
   * 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 ints[3];
  
  	get_options(str, 3, ints);
  	if (ints[0] < 2 || ints[1] < 1 ||
  			ints[1] > OMAP_I2C_MAX_CONTROLLERS)
  		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.
   */
  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;
  }
  
  /**
   * 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_MAX_CONTROLLERS);
  
  	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);
  }