arch/arm/plat-omap/i2c.c

   1 /*
   2  * linux/arch/arm/plat-omap/i2c.c
   3  *
   4  * Helper module for board specific I2C bus registration
   5  *
   6  * Copyright (C) 2007 Nokia Corporation.
   7  *
   8  * Contact: Jarkko Nikula <jhnikula@gmail.com>
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public License
  12  * version 2 as published by the Free Software Foundation.
  13  *
  14  * This program is distributed in the hope that it will be useful, but
  15  * WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  22  * 02110-1301 USA
  23  *
  24  */
  25
  26 #include <linux/kernel.h>
  27 #include <linux/platform_device.h>
  28 #include <linux/i2c.h>
  29 #include <mach/irqs.h>
  30 #include <plat/mux.h>
  31
  32 #define OMAP_I2C_SIZE           0x3f
  33 #define OMAP1_I2C_BASE          0xfffb3800
  34 #define OMAP2_I2C_BASE1         0x48070000
  35 #define OMAP2_I2C_BASE2         0x48072000
  36 #define OMAP2_I2C_BASE3         0x48060000
  37
  38 static const char name[] = "i2c_omap";
  39
  40 #define I2C_RESOURCE_BUILDER(base, irq)                 \
  41         {                                               \
  42                 .start  = (base),                       \
  43                 .end    = (base) + OMAP_I2C_SIZE,       \
  44                 .flags  = IORESOURCE_MEM,               \
  45         },                                              \
  46         {                                               \
  47                 .start  = (irq),                        \
  48                 .flags  = IORESOURCE_IRQ,               \
  49         },
  50
  51 static struct resource i2c_resources[][2] = {
  52         { I2C_RESOURCE_BUILDER(0, 0) },
  53 #if     defined(CONFIG_ARCH_OMAP2) || defined(CONFIG_ARCH_OMAP34XX)
  54         { I2C_RESOURCE_BUILDER(OMAP2_I2C_BASE2, INT_24XX_I2C2_IRQ) },
  55 #endif
  56 #if     defined(CONFIG_ARCH_OMAP34XX)
  57         { I2C_RESOURCE_BUILDER(OMAP2_I2C_BASE3, INT_34XX_I2C3_IRQ) },
  58 #endif
  59 };
  60
  61 #define I2C_DEV_BUILDER(bus_id, res, data)              \
  62         {                                               \
  63                 .id     = (bus_id),                     \
  64                 .name   = name,                         \
  65                 .num_resources  = ARRAY_SIZE(res),      \
  66                 .resource       = (res),                \
  67                 .dev            = {                     \
  68                         .platform_data  = (data),       \
  69                 },                                      \
  70         }
  71
  72 static u32 i2c_rate[ARRAY_SIZE(i2c_resources)];
  73 static struct platform_device omap_i2c_devices[] = {
  74         I2C_DEV_BUILDER(1, i2c_resources[0], &i2c_rate[0]),
  75 #if     defined(CONFIG_ARCH_OMAP2) || defined(CONFIG_ARCH_OMAP34XX)
  76         I2C_DEV_BUILDER(2, i2c_resources[1], &i2c_rate[1]),
  77 #endif
  78 #if     defined(CONFIG_ARCH_OMAP34XX)
  79         I2C_DEV_BUILDER(3, i2c_resources[2], &i2c_rate[2]),
  80 #endif
  81 };
  82
  83 #define OMAP_I2C_CMDLINE_SETUP  (BIT(31))
  84
  85 static int __init omap_i2c_nr_ports(void)
  86 {
  87         int ports = 0;
  88
  89         if (cpu_class_is_omap1())
  90                 ports = 1;
  91         else if (cpu_is_omap24xx())
  92                 ports = 2;
  93         else if (cpu_is_omap34xx())
  94                 ports = 3;
  95
  96         return ports;
  97 }
  98
  99 static int __init omap_i2c_add_bus(int bus_id)
 100 {
 101         struct platform_device *pdev;
 102         struct resource *res;
 103         resource_size_t base, irq;
 104
 105         pdev = &omap_i2c_devices[bus_id - 1];
 106         if (bus_id == 1) {
 107                 res = pdev->resource;
 108                 if (cpu_class_is_omap1()) {
 109                         base = OMAP1_I2C_BASE;
 110                         irq = INT_I2C;
 111                 } else {
 112                         base = OMAP2_I2C_BASE1;
 113                         irq = INT_24XX_I2C1_IRQ;
 114                 }
 115                 res[0].start = base;
 116                 res[0].end = base + OMAP_I2C_SIZE;
 117                 res[1].start = irq;
 118         }
 119
 120         return platform_device_register(pdev);
 121 }
 122
 123 /**
 124  * omap_i2c_bus_setup - Process command line options for the I2C bus speed
 125  * @str: String of options
 126  *
 127  * This function allow to override the default I2C bus speed for given I2C
 128  * bus with a command line option.
 129  *
 130  * Format: i2c_bus=bus_id,clkrate (in kHz)
 131  *
 132  * Returns 1 on success, 0 otherwise.
 133  */
 134 static int __init omap_i2c_bus_setup(char *str)
 135 {
 136         int ports;
 137         int ints[3];
 138
 139         ports = omap_i2c_nr_ports();
 140         get_options(str, 3, ints);
 141         if (ints[0] < 2 || ints[1] < 1 || ints[1] > ports)
 142                 return 0;
 143         i2c_rate[ints[1] - 1] = ints[2];
 144         i2c_rate[ints[1] - 1] |= OMAP_I2C_CMDLINE_SETUP;
 145
 146         return 1;
 147 }
 148 __setup("i2c_bus=", omap_i2c_bus_setup);
 149
 150 /*
 151  * Register busses defined in command line but that are not registered with
 152  * omap_register_i2c_bus from board initialization code.
 153  */
 154 static int __init omap_register_i2c_bus_cmdline(void)
 155 {
 156         int i, err = 0;
 157
 158         for (i = 0; i < ARRAY_SIZE(i2c_rate); i++)
 159                 if (i2c_rate[i] & OMAP_I2C_CMDLINE_SETUP) {
 160                         i2c_rate[i] &= ~OMAP_I2C_CMDLINE_SETUP;
 161                         err = omap_i2c_add_bus(i + 1);
 162                         if (err)
 163                                 goto out;
 164                 }
 165
 166 out:
 167         return err;
 168 }
 169 subsys_initcall(omap_register_i2c_bus_cmdline);
 170
 171 /**
 172  * omap_plat_register_i2c_bus - register I2C bus with device descriptors
 173  * @bus_id: bus id counting from number 1
 174  * @clkrate: clock rate of the bus in kHz
 175  * @info: pointer into I2C device descriptor table or NULL
 176  * @len: number of descriptors in the table
 177  *
 178  * Returns 0 on success or an error code.
 179  */
 180 int __init omap_plat_register_i2c_bus(int bus_id, u32 clkrate,
 181                           struct i2c_board_info const *info,
 182                           unsigned len)
 183 {
 184         int err;
 185
 186         BUG_ON(bus_id < 1 || bus_id > omap_i2c_nr_ports());
 187
 188         if (info) {
 189                 err = i2c_register_board_info(bus_id, info, len);
 190                 if (err)
 191                         return err;
 192         }
 193
 194         if (!i2c_rate[bus_id - 1])
 195                 i2c_rate[bus_id - 1] = clkrate;
 196         i2c_rate[bus_id - 1] &= ~OMAP_I2C_CMDLINE_SETUP;
 197
 198         return omap_i2c_add_bus(bus_id);
 199 }