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 #include <mach/mux.h>
11 #include "soc.h"
12
13 #define OMAP_I2C_SIZE 0x3f
14 #define OMAP1_I2C_BASE 0xfffb3800
15
16 static const char name[] = "omap_i2c";
17
18 static struct resource i2c_resources[2] = {
19 };
20
21 static struct platform_device omap_i2c_devices[1] = {
22 };
23
omap1_i2c_mux_pins(int bus_id)24 static void __init omap1_i2c_mux_pins(int bus_id)
25 {
26 if (cpu_is_omap7xx()) {
27 omap_cfg_reg(I2C_7XX_SDA);
28 omap_cfg_reg(I2C_7XX_SCL);
29 } else {
30 omap_cfg_reg(I2C_SDA);
31 omap_cfg_reg(I2C_SCL);
32 }
33 }
34
omap_i2c_add_bus(struct omap_i2c_bus_platform_data * pdata,int bus_id)35 int __init omap_i2c_add_bus(struct omap_i2c_bus_platform_data *pdata,
36 int bus_id)
37 {
38 struct platform_device *pdev;
39 struct resource *res;
40
41 if (bus_id > 1)
42 return -EINVAL;
43
44 omap1_i2c_mux_pins(bus_id);
45
46 pdev = &omap_i2c_devices[bus_id - 1];
47 pdev->id = bus_id;
48 pdev->name = name;
49 pdev->num_resources = ARRAY_SIZE(i2c_resources);
50 res = i2c_resources;
51 res[0].start = OMAP1_I2C_BASE;
52 res[0].end = res[0].start + OMAP_I2C_SIZE;
53 res[0].flags = IORESOURCE_MEM;
54 res[1].start = INT_I2C;
55 res[1].flags = IORESOURCE_IRQ;
56 pdev->resource = res;
57
58 /* all OMAP1 have IP version 1 register set */
59 pdata->rev = OMAP_I2C_IP_VERSION_1;
60
61 /* all OMAP1 I2C are implemented like this */
62 pdata->flags = OMAP_I2C_FLAG_NO_FIFO |
63 OMAP_I2C_FLAG_SIMPLE_CLOCK |
64 OMAP_I2C_FLAG_16BIT_DATA_REG |
65 OMAP_I2C_FLAG_ALWAYS_ARMXOR_CLK;
66
67 /* how the cpu bus is wired up differs for 7xx only */
68
69 if (cpu_is_omap7xx())
70 pdata->flags |= OMAP_I2C_FLAG_BUS_SHIFT_1;
71 else
72 pdata->flags |= OMAP_I2C_FLAG_BUS_SHIFT_2;
73
74 pdev->dev.platform_data = pdata;
75
76 return platform_device_register(pdev);
77 }
78
79 #define OMAP_I2C_MAX_CONTROLLERS 4
80 static struct omap_i2c_bus_platform_data i2c_pdata[OMAP_I2C_MAX_CONTROLLERS];
81
82 #define OMAP_I2C_CMDLINE_SETUP (BIT(31))
83
84 /**
85 * omap_i2c_bus_setup - Process command line options for the I2C bus speed
86 * @str: String of options
87 *
88 * This function allow to override the default I2C bus speed for given I2C
89 * bus with a command line option.
90 *
91 * Format: i2c_bus=bus_id,clkrate (in kHz)
92 *
93 * Returns 1 on success, 0 otherwise.
94 */
omap_i2c_bus_setup(char * str)95 static int __init omap_i2c_bus_setup(char *str)
96 {
97 int ints[3];
98
99 get_options(str, 3, ints);
100 if (ints[0] < 2 || ints[1] < 1 ||
101 ints[1] > OMAP_I2C_MAX_CONTROLLERS)
102 return 0;
103 i2c_pdata[ints[1] - 1].clkrate = ints[2];
104 i2c_pdata[ints[1] - 1].clkrate |= OMAP_I2C_CMDLINE_SETUP;
105
106 return 1;
107 }
108 __setup("i2c_bus=", omap_i2c_bus_setup);
109
110 /*
111 * Register busses defined in command line but that are not registered with
112 * omap_register_i2c_bus from board initialization code.
113 */
omap_register_i2c_bus_cmdline(void)114 int __init omap_register_i2c_bus_cmdline(void)
115 {
116 int i, err = 0;
117
118 for (i = 0; i < ARRAY_SIZE(i2c_pdata); i++)
119 if (i2c_pdata[i].clkrate & OMAP_I2C_CMDLINE_SETUP) {
120 i2c_pdata[i].clkrate &= ~OMAP_I2C_CMDLINE_SETUP;
121 err = omap_i2c_add_bus(&i2c_pdata[i], i + 1);
122 if (err)
123 goto out;
124 }
125
126 out:
127 return err;
128 }
129
130 /**
131 * omap_register_i2c_bus - register I2C bus with device descriptors
132 * @bus_id: bus id counting from number 1
133 * @clkrate: clock rate of the bus in kHz
134 * @info: pointer into I2C device descriptor table or NULL
135 * @len: number of descriptors in the table
136 *
137 * Returns 0 on success or an error code.
138 */
omap_register_i2c_bus(int bus_id,u32 clkrate,struct i2c_board_info const * info,unsigned len)139 int __init omap_register_i2c_bus(int bus_id, u32 clkrate,
140 struct i2c_board_info const *info,
141 unsigned len)
142 {
143 int err;
144
145 BUG_ON(bus_id < 1 || bus_id > OMAP_I2C_MAX_CONTROLLERS);
146
147 if (info) {
148 err = i2c_register_board_info(bus_id, info, len);
149 if (err)
150 return err;
151 }
152
153 if (!i2c_pdata[bus_id - 1].clkrate)
154 i2c_pdata[bus_id - 1].clkrate = clkrate;
155
156 i2c_pdata[bus_id - 1].clkrate &= ~OMAP_I2C_CMDLINE_SETUP;
157
158 return omap_i2c_add_bus(&i2c_pdata[bus_id - 1], bus_id);
159 }
160
omap_i2c_cmdline(void)161 static int __init omap_i2c_cmdline(void)
162 {
163 return omap_register_i2c_bus_cmdline();
164 }
165 subsys_initcall(omap_i2c_cmdline);
166