LXR linux/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#include <mach/mux.h>
  11#include "soc.h"
  12
  13#define OMAP_I2C_SIZE           0x3f
  14#define OMAP1_I2C_BASE          0xfffb3800
  15
  16static const char name[] = "omap_i2c";
  17
  18static struct resource i2c_resources[2] = {
  19};
  20
  21static struct platform_device omap_i2c_devices[1] = {
  22};
  23
  24static 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
  35int __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
  80static 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 */
  95static 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 */
 114int __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
 126out:
 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 */
 139int __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
 161static  int __init omap_i2c_cmdline(void)
 162{
 163        return omap_register_i2c_bus_cmdline();
 164}
 165subsys_initcall(omap_i2c_cmdline);
 166