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
omap1_i2c_mux_pins(int bus_id)26 static void __init omap1_i2c_mux_pins(int bus_id)
27 {
28 if (cpu_is_omap7xx()) {
29 omap_cfg_reg(I2C_7XX_SDA);
30 omap_cfg_reg(I2C_7XX_SCL);
31 } else {
32 omap_cfg_reg(I2C_SDA);
33 omap_cfg_reg(I2C_SCL);
34 }
35 }
36
omap_i2c_add_bus(struct omap_i2c_bus_platform_data * pdata,int bus_id)37 int __init omap_i2c_add_bus(struct omap_i2c_bus_platform_data *pdata,
38 int bus_id)
39 {
40 struct platform_device *pdev;
41 struct resource *res;
42
43 if (bus_id > 1)
44 return -EINVAL;
45
46 omap1_i2c_mux_pins(bus_id);
47
48 pdev = &omap_i2c_devices[bus_id - 1];
49 pdev->id = bus_id;
50 pdev->name = name;
51 pdev->num_resources = ARRAY_SIZE(i2c_resources);
52 res = i2c_resources;
53 res[0].start = OMAP1_I2C_BASE;
54 res[0].end = res[0].start + OMAP_I2C_SIZE;
55 res[0].flags = IORESOURCE_MEM;
56 res[1].start = INT_I2C;
57 res[1].flags = IORESOURCE_IRQ;
58 pdev->resource = res;
59
60 /* all OMAP1 have IP version 1 register set */
61 pdata->rev = OMAP_I2C_IP_VERSION_1;
62
63 /* all OMAP1 I2C are implemented like this */
64 pdata->flags = OMAP_I2C_FLAG_NO_FIFO |
65 OMAP_I2C_FLAG_SIMPLE_CLOCK |
66 OMAP_I2C_FLAG_16BIT_DATA_REG |
67 OMAP_I2C_FLAG_ALWAYS_ARMXOR_CLK;
68
69 /* how the cpu bus is wired up differs for 7xx only */
70
71 if (cpu_is_omap7xx())
72 pdata->flags |= OMAP_I2C_FLAG_BUS_SHIFT_1;
73 else
74 pdata->flags |= OMAP_I2C_FLAG_BUS_SHIFT_2;
75
76 pdev->dev.platform_data = pdata;
77
78 return platform_device_register(pdev);
79 }
80
81 #define OMAP_I2C_MAX_CONTROLLERS 4
82 static struct omap_i2c_bus_platform_data i2c_pdata[OMAP_I2C_MAX_CONTROLLERS];
83
84 #define OMAP_I2C_CMDLINE_SETUP (BIT(31))
85
86 /**
87 * omap_i2c_bus_setup - Process command line options for the I2C bus speed
88 * @str: String of options
89 *
90 * This function allow to override the default I2C bus speed for given I2C
91 * bus with a command line option.
92 *
93 * Format: i2c_bus=bus_id,clkrate (in kHz)
94 *
95 * Returns 1 on success, 0 otherwise.
96 */
omap_i2c_bus_setup(char * str)97 static int __init omap_i2c_bus_setup(char *str)
98 {
99 int ints[3];
100
101 get_options(str, 3, ints);
102 if (ints[0] < 2 || ints[1] < 1 ||
103 ints[1] > OMAP_I2C_MAX_CONTROLLERS)
104 return 0;
105 i2c_pdata[ints[1] - 1].clkrate = ints[2];
106 i2c_pdata[ints[1] - 1].clkrate |= OMAP_I2C_CMDLINE_SETUP;
107
108 return 1;
109 }
110 __setup("i2c_bus=", omap_i2c_bus_setup);
111
112 /*
113 * Register busses defined in command line but that are not registered with
114 * omap_register_i2c_bus from board initialization code.
115 */
omap_register_i2c_bus_cmdline(void)116 int __init omap_register_i2c_bus_cmdline(void)
117 {
118 int i, err = 0;
119
120 for (i = 0; i < ARRAY_SIZE(i2c_pdata); i++)
121 if (i2c_pdata[i].clkrate & OMAP_I2C_CMDLINE_SETUP) {
122 i2c_pdata[i].clkrate &= ~OMAP_I2C_CMDLINE_SETUP;
123 err = omap_i2c_add_bus(&i2c_pdata[i], i + 1);
124 if (err)
125 goto out;
126 }
127
128 out:
129 return err;
130 }
131
132 /**
133 * omap_register_i2c_bus - register I2C bus with device descriptors
134 * @bus_id: bus id counting from number 1
135 * @clkrate: clock rate of the bus in kHz
136 * @info: pointer into I2C device descriptor table or NULL
137 * @len: number of descriptors in the table
138 *
139 * Returns 0 on success or an error code.
140 */
omap_register_i2c_bus(int bus_id,u32 clkrate,struct i2c_board_info const * info,unsigned len)141 int __init omap_register_i2c_bus(int bus_id, u32 clkrate,
142 struct i2c_board_info const *info,
143 unsigned len)
144 {
145 int err;
146
147 BUG_ON(bus_id < 1 || bus_id > OMAP_I2C_MAX_CONTROLLERS);
148
149 if (info) {
150 err = i2c_register_board_info(bus_id, info, len);
151 if (err)
152 return err;
153 }
154
155 if (!i2c_pdata[bus_id - 1].clkrate)
156 i2c_pdata[bus_id - 1].clkrate = clkrate;
157
158 i2c_pdata[bus_id - 1].clkrate &= ~OMAP_I2C_CMDLINE_SETUP;
159
160 return omap_i2c_add_bus(&i2c_pdata[bus_id - 1], bus_id);
161 }
162
omap_i2c_cmdline(void)163 static int __init omap_i2c_cmdline(void)
164 {
165 return omap_register_i2c_bus_cmdline();
166 }
167 subsys_initcall(omap_i2c_cmdline);
168
