arch/arm/mach-omap1/i2c.c

   1 /*
   2  * Helper module for board specific I2C bus registration
   3  *
   4  * Copyright (C) 2009 Nokia Corporation.
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * version 2 as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  18  * 02110-1301 USA
  19  *
  20  */
  21
  22 #include <linux/i2c.h>
  23 #include <linux/platform_data/i2c-omap.h>
  24 #include <mach/mux.h>
  25 #include "soc.h"
  26
  27 #define OMAP_I2C_SIZE           0x3f
  28 #define OMAP1_I2C_BASE          0xfffb3800
  29
  30 static const char name[] = "omap_i2c";
  31
  32 static struct resource i2c_resources[2] = {
  33 };
  34
  35 static struct platform_device omap_i2c_devices[1] = {
  36 };
  37
  38 static void __init omap1_i2c_mux_pins(int bus_id)
  39 {
  40         if (cpu_is_omap7xx()) {
  41                 omap_cfg_reg(I2C_7XX_SDA);
  42                 omap_cfg_reg(I2C_7XX_SCL);
  43         } else {
  44                 omap_cfg_reg(I2C_SDA);
  45                 omap_cfg_reg(I2C_SCL);
  46         }
  47 }
  48
  49 int __init omap_i2c_add_bus(struct omap_i2c_bus_platform_data *pdata,
  50                                 int bus_id)
  51 {
  52         struct platform_device *pdev;
  53         struct resource *res;
  54
  55         if (bus_id > 1)
  56                 return -EINVAL;
  57
  58         omap1_i2c_mux_pins(bus_id);
  59
  60         pdev = &omap_i2c_devices[bus_id - 1];
  61         pdev->id = bus_id;
  62         pdev->name = name;
  63         pdev->num_resources = ARRAY_SIZE(i2c_resources);
  64         res = i2c_resources;
  65         res[0].start = OMAP1_I2C_BASE;
  66         res[0].end = res[0].start + OMAP_I2C_SIZE;
  67         res[0].flags = IORESOURCE_MEM;
  68         res[1].start = INT_I2C;
  69         res[1].flags = IORESOURCE_IRQ;
  70         pdev->resource = res;
  71
  72         /* all OMAP1 have IP version 1 register set */
  73         pdata->rev = OMAP_I2C_IP_VERSION_1;
  74
  75         /* all OMAP1 I2C are implemented like this */
  76         pdata->flags = OMAP_I2C_FLAG_NO_FIFO |
  77                        OMAP_I2C_FLAG_SIMPLE_CLOCK |
  78                        OMAP_I2C_FLAG_16BIT_DATA_REG |
  79                        OMAP_I2C_FLAG_ALWAYS_ARMXOR_CLK;
  80
  81         /* how the cpu bus is wired up differs for 7xx only */
  82
  83         if (cpu_is_omap7xx())
  84                 pdata->flags |= OMAP_I2C_FLAG_BUS_SHIFT_1;
  85         else
  86                 pdata->flags |= OMAP_I2C_FLAG_BUS_SHIFT_2;
  87
  88         pdev->dev.platform_data = pdata;
  89
  90         return platform_device_register(pdev);
  91 }
  92
  93 #define OMAP_I2C_MAX_CONTROLLERS 4
  94 static struct omap_i2c_bus_platform_data i2c_pdata[OMAP_I2C_MAX_CONTROLLERS];
  95
  96 #define OMAP_I2C_CMDLINE_SETUP  (BIT(31))
  97
  98 /**
  99  * omap_i2c_bus_setup - Process command line options for the I2C bus speed
 100  * @str: String of options
 101  *
 102  * This function allow to override the default I2C bus speed for given I2C
 103  * bus with a command line option.
 104  *
 105  * Format: i2c_bus=bus_id,clkrate (in kHz)
 106  *
 107  * Returns 1 on success, 0 otherwise.
 108  */
 109 static int __init omap_i2c_bus_setup(char *str)
 110 {
 111         int ints[3];
 112
 113         get_options(str, 3, ints);
 114         if (ints[0] < 2 || ints[1] < 1 ||
 115                         ints[1] > OMAP_I2C_MAX_CONTROLLERS)
 116                 return 0;
 117         i2c_pdata[ints[1] - 1].clkrate = ints[2];
 118         i2c_pdata[ints[1] - 1].clkrate |= OMAP_I2C_CMDLINE_SETUP;
 119
 120         return 1;
 121 }
 122 __setup("i2c_bus=", omap_i2c_bus_setup);
 123
 124 /*
 125  * Register busses defined in command line but that are not registered with
 126  * omap_register_i2c_bus from board initialization code.
 127  */
 128 int __init omap_register_i2c_bus_cmdline(void)
 129 {
 130         int i, err = 0;
 131
 132         for (i = 0; i < ARRAY_SIZE(i2c_pdata); i++)
 133                 if (i2c_pdata[i].clkrate & OMAP_I2C_CMDLINE_SETUP) {
 134                         i2c_pdata[i].clkrate &= ~OMAP_I2C_CMDLINE_SETUP;
 135                         err = omap_i2c_add_bus(&i2c_pdata[i], i + 1);
 136                         if (err)
 137                                 goto out;
 138                 }
 139
 140 out:
 141         return err;
 142 }
 143
 144 /**
 145  * omap_register_i2c_bus - register I2C bus with device descriptors
 146  * @bus_id: bus id counting from number 1
 147  * @clkrate: clock rate of the bus in kHz
 148  * @info: pointer into I2C device descriptor table or NULL
 149  * @len: number of descriptors in the table
 150  *
 151  * Returns 0 on success or an error code.
 152  */
 153 int __init omap_register_i2c_bus(int bus_id, u32 clkrate,
 154                           struct i2c_board_info const *info,
 155                           unsigned len)
 156 {
 157         int err;
 158
 159         BUG_ON(bus_id < 1 || bus_id > OMAP_I2C_MAX_CONTROLLERS);
 160
 161         if (info) {
 162                 err = i2c_register_board_info(bus_id, info, len);
 163                 if (err)
 164                         return err;
 165         }
 166
 167         if (!i2c_pdata[bus_id - 1].clkrate)
 168                 i2c_pdata[bus_id - 1].clkrate = clkrate;
 169
 170         i2c_pdata[bus_id - 1].clkrate &= ~OMAP_I2C_CMDLINE_SETUP;
 171
 172         return omap_i2c_add_bus(&i2c_pdata[bus_id - 1], bus_id);
 173 }
 174
 175 static  int __init omap_i2c_cmdline(void)
 176 {
 177         return omap_register_i2c_bus_cmdline();
 178 }
 179 subsys_initcall(omap_i2c_cmdline);