1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Helper module for board specific I2C bus registration
4 *
5 * Copyright (C) 2009 Nokia Corporation.
6 */
7
8 #include <linux/i2c.h>
9 #include <linux/platform_data/i2c-omap.h>
10
11 #include "mux.h"
12 #include "soc.h"
13 #include "i2c.h"
14
15 #define OMAP_I2C_SIZE 0x3f
16 #define OMAP1_I2C_BASE 0xfffb3800
17
18 static const char name[] = "omap_i2c";
19
20 static struct resource i2c_resources[2] = {
21 };
22
23 static struct platform_device omap_i2c_devices[1] = {
24 };
25
26 static void __init omap1_i2c_mux_pins(int bus_id)
27 {
28 omap_cfg_reg(I2C_SDA);
29 omap_cfg_reg(I2C_SCL);
30 }
31
32 int __init omap_i2c_add_bus(struct omap_i2c_bus_platform_data *pdata,
33 int bus_id)
34 {
35 struct platform_device *pdev;
36 struct resource *res;
37
38 if (bus_id > 1)
39 return -EINVAL;
40
41 omap1_i2c_mux_pins(bus_id);
42
43 pdev = &omap_i2c_devices[bus_id - 1];
44 pdev->id = bus_id;
45 pdev->name = name;
46 pdev->num_resources = ARRAY_SIZE(i2c_resources);
47 res = i2c_resources;
48 res[0].start = OMAP1_I2C_BASE;
49 res[0].end = res[0].start + OMAP_I2C_SIZE;
50 res[0].flags = IORESOURCE_MEM;
51 res[1].start = INT_I2C;
52 res[1].flags = IORESOURCE_IRQ;
53 pdev->resource = res;
54
55 /* all OMAP1 have IP version 1 register set */
56 pdata->rev = OMAP_I2C_IP_VERSION_1;
57
58 /* all OMAP1 I2C are implemented like this */
59 pdata->flags = OMAP_I2C_FLAG_NO_FIFO |
60 OMAP_I2C_FLAG_SIMPLE_CLOCK |
61 OMAP_I2C_FLAG_16BIT_DATA_REG |
62 OMAP_I2C_FLAG_ALWAYS_ARMXOR_CLK;
63
64 /* how the cpu bus is wired up differs for 7xx only */
65
66 pdata->flags |= OMAP_I2C_FLAG_BUS_SHIFT_2;
67
68 pdev->dev.platform_data = pdata;
69
70 return platform_device_register(pdev);
71 }
72
73 #define OMAP_I2C_MAX_CONTROLLERS 4
74 static struct omap_i2c_bus_platform_data i2c_pdata[OMAP_I2C_MAX_CONTROLLERS];
75
76 #define OMAP_I2C_CMDLINE_SETUP (BIT(31))
77
78 /**
79 * omap_i2c_bus_setup - Process command line options for the I2C bus speed
80 * @str: String of options
81 *
82 * This function allow to override the default I2C bus speed for given I2C
83 * bus with a command line option.
84 *
85 * Format: i2c_bus=bus_id,clkrate (in kHz)
86 *
87 * Returns 1 on success, 0 otherwise.
88 */
89 static int __init omap_i2c_bus_setup(char *str)
90 {
91 int ints[3];
92
93 get_options(str, 3, ints);
94 if (ints[0] < 2 || ints[1] < 1 ||
95 ints[1] > OMAP_I2C_MAX_CONTROLLERS)
96 return 0;
97 i2c_pdata[ints[1] - 1].clkrate = ints[2];
98 i2c_pdata[ints[1] - 1].clkrate |= OMAP_I2C_CMDLINE_SETUP;
99
100 return 1;
101 }
102 __setup("i2c_bus=", omap_i2c_bus_setup);
103
104 /*
105 * Register busses defined in command line but that are not registered with
106 * omap_register_i2c_bus from board initialization code.
107 */
108 int __init omap_register_i2c_bus_cmdline(void)
109 {
110 int i, err = 0;
111
112 for (i = 0; i < ARRAY_SIZE(i2c_pdata); i++)
113 if (i2c_pdata[i].clkrate & OMAP_I2C_CMDLINE_SETUP) {
114 i2c_pdata[i].clkrate &= ~OMAP_I2C_CMDLINE_SETUP;
115 err = omap_i2c_add_bus(&i2c_pdata[i], i + 1);
116 if (err)
117 goto out;
118 }
119
120 out:
121 return err;
122 }
123
124 /**
125 * omap_register_i2c_bus - register I2C bus with device descriptors
126 * @bus_id: bus id counting from number 1
127 * @clkrate: clock rate of the bus in kHz
128 * @info: pointer into I2C device descriptor table or NULL
129 * @len: number of descriptors in the table
130 *
131 * Returns 0 on success or an error code.
132 */
133 int __init omap_register_i2c_bus(int bus_id, u32 clkrate,
134 struct i2c_board_info const *info,
135 unsigned len)
136 {
137 int err;
138
139 BUG_ON(bus_id < 1 || bus_id > OMAP_I2C_MAX_CONTROLLERS);
140
141 if (info) {
142 err = i2c_register_board_info(bus_id, info, len);
143 if (err)
144 return err;
145 }
146
147 if (!i2c_pdata[bus_id - 1].clkrate)
148 i2c_pdata[bus_id - 1].clkrate = clkrate;
149
150 i2c_pdata[bus_id - 1].clkrate &= ~OMAP_I2C_CMDLINE_SETUP;
151
152 return omap_i2c_add_bus(&i2c_pdata[bus_id - 1], bus_id);
153 }
154
155 static int __init omap_i2c_cmdline(void)
156 {
157 return omap_register_i2c_bus_cmdline();
158 }
159 subsys_initcall(omap_i2c_cmdline);
160
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