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         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
  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  */
  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  */
 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  */
 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
 163 static  int __init omap_i2c_cmdline(void)
 164 {
 165         return omap_register_i2c_bus_cmdline();
 166 }
 167 subsys_initcall(omap_i2c_cmdline);