xref: /openbmc/linux/arch/arm/mach-omap1/i2c.c (revision 8825acd7)
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 	omap_cfg_reg(I2C_SDA);
29 	omap_cfg_reg(I2C_SCL);
30 }
31 
omap_i2c_add_bus(struct omap_i2c_bus_platform_data * pdata,int bus_id)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  */
omap_i2c_bus_setup(char * str)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  */
omap_register_i2c_bus_cmdline(void)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  */
omap_register_i2c_bus(int bus_id,u32 clkrate,struct i2c_board_info const * info,unsigned len)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 
omap_i2c_cmdline(void)155 static  int __init omap_i2c_cmdline(void)
156 {
157 	return omap_register_i2c_bus_cmdline();
158 }
159 subsys_initcall(omap_i2c_cmdline);
160