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
  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
  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
  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  */
  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  */
 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  */
 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
 161 static  int __init omap_i2c_cmdline(void)
 162 {
 163         return omap_register_i2c_bus_cmdline();
 164 }
 165 subsys_initcall(omap_i2c_cmdline);