arch/arm/mach-omap1/i2c.c

   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);