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 <mach/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_OMAP24XX) || 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_OMAP24XX) || 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 #if defined(CONFIG_ARCH_OMAP24XX)
  84 static const int omap24xx_pins[][2] = {
  85         { M19_24XX_I2C1_SCL, L15_24XX_I2C1_SDA },
  86         { J15_24XX_I2C2_SCL, H19_24XX_I2C2_SDA },
  87 };
  88 #else
  89 static const int omap24xx_pins[][2] = {};
  90 #endif
  91 #if defined(CONFIG_ARCH_OMAP34XX)
  92 static const int omap34xx_pins[][2] = {
  93         { K21_34XX_I2C1_SCL, J21_34XX_I2C1_SDA},
  94         { AF15_34XX_I2C2_SCL, AE15_34XX_I2C2_SDA},
  95         { AF14_34XX_I2C3_SCL, AG14_34XX_I2C3_SDA},
  96 };
  97 #else
  98 static const int omap34xx_pins[][2] = {};
  99 #endif
 100
 101 #define OMAP_I2C_CMDLINE_SETUP  (BIT(31))
 102
 103 static void __init omap_i2c_mux_pins(int bus)
 104 {
 105         int scl, sda;
 106
 107         if (cpu_class_is_omap1()) {
 108                 scl = I2C_SCL;
 109                 sda = I2C_SDA;
 110         } else if (cpu_is_omap24xx()) {
 111                 scl = omap24xx_pins[bus][0];
 112                 sda = omap24xx_pins[bus][1];
 113         } else if (cpu_is_omap34xx()) {
 114                 scl = omap34xx_pins[bus][0];
 115                 sda = omap34xx_pins[bus][1];
 116         } else {
 117                 return;
 118         }
 119
 120         omap_cfg_reg(sda);
 121         omap_cfg_reg(scl);
 122 }
 123
 124 static int __init omap_i2c_nr_ports(void)
 125 {
 126         int ports = 0;
 127
 128         if (cpu_class_is_omap1())
 129                 ports = 1;
 130         else if (cpu_is_omap24xx())
 131                 ports = 2;
 132         else if (cpu_is_omap34xx())
 133                 ports = 3;
 134
 135         return ports;
 136 }
 137
 138 static int __init omap_i2c_add_bus(int bus_id)
 139 {
 140         struct platform_device *pdev;
 141         struct resource *res;
 142         resource_size_t base, irq;
 143
 144         pdev = &omap_i2c_devices[bus_id - 1];
 145         if (bus_id == 1) {
 146                 res = pdev->resource;
 147                 if (cpu_class_is_omap1()) {
 148                         base = OMAP1_I2C_BASE;
 149                         irq = INT_I2C;
 150                 } else {
 151                         base = OMAP2_I2C_BASE1;
 152                         irq = INT_24XX_I2C1_IRQ;
 153                 }
 154                 res[0].start = base;
 155                 res[0].end = base + OMAP_I2C_SIZE;
 156                 res[1].start = irq;
 157         }
 158
 159         omap_i2c_mux_pins(bus_id - 1);
 160         return platform_device_register(pdev);
 161 }
 162
 163 /**
 164  * omap_i2c_bus_setup - Process command line options for the I2C bus speed
 165  * @str: String of options
 166  *
 167  * This function allow to override the default I2C bus speed for given I2C
 168  * bus with a command line option.
 169  *
 170  * Format: i2c_bus=bus_id,clkrate (in kHz)
 171  *
 172  * Returns 1 on success, 0 otherwise.
 173  */
 174 static int __init omap_i2c_bus_setup(char *str)
 175 {
 176         int ports;
 177         int ints[3];
 178
 179         ports = omap_i2c_nr_ports();
 180         get_options(str, 3, ints);
 181         if (ints[0] < 2 || ints[1] < 1 || ints[1] > ports)
 182                 return 0;
 183         i2c_rate[ints[1] - 1] = ints[2];
 184         i2c_rate[ints[1] - 1] |= OMAP_I2C_CMDLINE_SETUP;
 185
 186         return 1;
 187 }
 188 __setup("i2c_bus=", omap_i2c_bus_setup);
 189
 190 /*
 191  * Register busses defined in command line but that are not registered with
 192  * omap_register_i2c_bus from board initialization code.
 193  */
 194 static int __init omap_register_i2c_bus_cmdline(void)
 195 {
 196         int i, err = 0;
 197
 198         for (i = 0; i < ARRAY_SIZE(i2c_rate); i++)
 199                 if (i2c_rate[i] & OMAP_I2C_CMDLINE_SETUP) {
 200                         i2c_rate[i] &= ~OMAP_I2C_CMDLINE_SETUP;
 201                         err = omap_i2c_add_bus(i + 1);
 202                         if (err)
 203                                 goto out;
 204                 }
 205
 206 out:
 207         return err;
 208 }
 209 subsys_initcall(omap_register_i2c_bus_cmdline);
 210
 211 /**
 212  * omap_register_i2c_bus - register I2C bus with device descriptors
 213  * @bus_id: bus id counting from number 1
 214  * @clkrate: clock rate of the bus in kHz
 215  * @info: pointer into I2C device descriptor table or NULL
 216  * @len: number of descriptors in the table
 217  *
 218  * Returns 0 on success or an error code.
 219  */
 220 int __init omap_register_i2c_bus(int bus_id, u32 clkrate,
 221                           struct i2c_board_info const *info,
 222                           unsigned len)
 223 {
 224         int err;
 225
 226         BUG_ON(bus_id < 1 || bus_id > omap_i2c_nr_ports());
 227
 228         if (info) {
 229                 err = i2c_register_board_info(bus_id, info, len);
 230                 if (err)
 231                         return err;
 232         }
 233
 234         if (!i2c_rate[bus_id - 1])
 235                 i2c_rate[bus_id - 1] = clkrate;
 236         i2c_rate[bus_id - 1] &= ~OMAP_I2C_CMDLINE_SETUP;
 237
 238         return omap_i2c_add_bus(bus_id);
 239 }