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/i2c-omap.h>
  24 #include <mach/mux.h>
  25 #include "soc.h"
  26
  27 #include <plat/i2c.h>
  28
  29 #define OMAP_I2C_SIZE           0x3f
  30 #define OMAP1_I2C_BASE          0xfffb3800
  31
  32 static const char name[] = "omap_i2c";
  33
  34 static struct resource i2c_resources[2] = {
  35 };
  36
  37 static struct platform_device omap_i2c_devices[1] = {
  38 };
  39
  40 static void __init omap1_i2c_mux_pins(int bus_id)
  41 {
  42         if (cpu_is_omap7xx()) {
  43                 omap_cfg_reg(I2C_7XX_SDA);
  44                 omap_cfg_reg(I2C_7XX_SCL);
  45         } else {
  46                 omap_cfg_reg(I2C_SDA);
  47                 omap_cfg_reg(I2C_SCL);
  48         }
  49 }
  50
  51 int __init omap_i2c_add_bus(struct omap_i2c_bus_platform_data *pdata,
  52                                 int bus_id)
  53 {
  54         struct platform_device *pdev;
  55         struct resource *res;
  56
  57         if (bus_id > 1)
  58                 return -EINVAL;
  59
  60         omap1_i2c_mux_pins(bus_id);
  61
  62         pdev = &omap_i2c_devices[bus_id - 1];
  63         pdev->id = bus_id;
  64         pdev->name = name;
  65         pdev->num_resources = ARRAY_SIZE(i2c_resources);
  66         res = i2c_resources;
  67         res[0].start = OMAP1_I2C_BASE;
  68         res[0].end = res[0].start + OMAP_I2C_SIZE;
  69         res[0].flags = IORESOURCE_MEM;
  70         res[1].start = INT_I2C;
  71         res[1].flags = IORESOURCE_IRQ;
  72         pdev->resource = res;
  73
  74         /* all OMAP1 have IP version 1 register set */
  75         pdata->rev = OMAP_I2C_IP_VERSION_1;
  76
  77         /* all OMAP1 I2C are implemented like this */
  78         pdata->flags = OMAP_I2C_FLAG_NO_FIFO |
  79                        OMAP_I2C_FLAG_SIMPLE_CLOCK |
  80                        OMAP_I2C_FLAG_16BIT_DATA_REG |
  81                        OMAP_I2C_FLAG_ALWAYS_ARMXOR_CLK;
  82
  83         /* how the cpu bus is wired up differs for 7xx only */
  84
  85         if (cpu_is_omap7xx())
  86                 pdata->flags |= OMAP_I2C_FLAG_BUS_SHIFT_1;
  87         else
  88                 pdata->flags |= OMAP_I2C_FLAG_BUS_SHIFT_2;
  89
  90         pdev->dev.platform_data = pdata;
  91
  92         return platform_device_register(pdev);
  93 }
  94
  95 #define OMAP_I2C_MAX_CONTROLLERS 4
  96 static struct omap_i2c_bus_platform_data i2c_pdata[OMAP_I2C_MAX_CONTROLLERS];
  97
  98 #define OMAP_I2C_CMDLINE_SETUP  (BIT(31))
  99
 100 /**
 101  * omap_i2c_bus_setup - Process command line options for the I2C bus speed
 102  * @str: String of options
 103  *
 104  * This function allow to override the default I2C bus speed for given I2C
 105  * bus with a command line option.
 106  *
 107  * Format: i2c_bus=bus_id,clkrate (in kHz)
 108  *
 109  * Returns 1 on success, 0 otherwise.
 110  */
 111 static int __init omap_i2c_bus_setup(char *str)
 112 {
 113         int ints[3];
 114
 115         get_options(str, 3, ints);
 116         if (ints[0] < 2 || ints[1] < 1 ||
 117                         ints[1] > OMAP_I2C_MAX_CONTROLLERS)
 118                 return 0;
 119         i2c_pdata[ints[1] - 1].clkrate = ints[2];
 120         i2c_pdata[ints[1] - 1].clkrate |= OMAP_I2C_CMDLINE_SETUP;
 121
 122         return 1;
 123 }
 124 __setup("i2c_bus=", omap_i2c_bus_setup);
 125
 126 /*
 127  * Register busses defined in command line but that are not registered with
 128  * omap_register_i2c_bus from board initialization code.
 129  */
 130 int __init omap_register_i2c_bus_cmdline(void)
 131 {
 132         int i, err = 0;
 133
 134         for (i = 0; i < ARRAY_SIZE(i2c_pdata); i++)
 135                 if (i2c_pdata[i].clkrate & OMAP_I2C_CMDLINE_SETUP) {
 136                         i2c_pdata[i].clkrate &= ~OMAP_I2C_CMDLINE_SETUP;
 137                         err = omap_i2c_add_bus(&i2c_pdata[i], i + 1);
 138                         if (err)
 139                                 goto out;
 140                 }
 141
 142 out:
 143         return err;
 144 }
 145
 146 /**
 147  * omap_register_i2c_bus - register I2C bus with device descriptors
 148  * @bus_id: bus id counting from number 1
 149  * @clkrate: clock rate of the bus in kHz
 150  * @info: pointer into I2C device descriptor table or NULL
 151  * @len: number of descriptors in the table
 152  *
 153  * Returns 0 on success or an error code.
 154  */
 155 int __init omap_register_i2c_bus(int bus_id, u32 clkrate,
 156                           struct i2c_board_info const *info,
 157                           unsigned len)
 158 {
 159         int err;
 160
 161         BUG_ON(bus_id < 1 || bus_id > OMAP_I2C_MAX_CONTROLLERS);
 162
 163         if (info) {
 164                 err = i2c_register_board_info(bus_id, info, len);
 165                 if (err)
 166                         return err;
 167         }
 168
 169         if (!i2c_pdata[bus_id - 1].clkrate)
 170                 i2c_pdata[bus_id - 1].clkrate = clkrate;
 171
 172         i2c_pdata[bus_id - 1].clkrate &= ~OMAP_I2C_CMDLINE_SETUP;
 173
 174         return omap_i2c_add_bus(&i2c_pdata[bus_id - 1], bus_id);
 175 }
 176
 177 static  int __init omap_i2c_cmdline(void)
 178 {
 179         return omap_register_i2c_bus_cmdline();
 180 }
 181 subsys_initcall(omap_i2c_cmdline);