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 <linux/i2c-omap.h>
  30
  31 #include <mach/irqs.h>
  32 #include <plat/mux.h>
  33 #include <plat/i2c.h>
  34 #include <plat/omap-pm.h>
  35
  36 #define OMAP_I2C_SIZE           0x3f
  37 #define OMAP1_I2C_BASE          0xfffb3800
  38 #define OMAP2_I2C_BASE1         0x48070000
  39 #define OMAP2_I2C_BASE2         0x48072000
  40 #define OMAP2_I2C_BASE3         0x48060000
  41
  42 static const char name[] = "i2c_omap";
  43
  44 #define I2C_RESOURCE_BUILDER(base, irq)                 \
  45         {                                               \
  46                 .start  = (base),                       \
  47                 .end    = (base) + OMAP_I2C_SIZE,       \
  48                 .flags  = IORESOURCE_MEM,               \
  49         },                                              \
  50         {                                               \
  51                 .start  = (irq),                        \
  52                 .flags  = IORESOURCE_IRQ,               \
  53         },
  54
  55 static struct resource i2c_resources[][2] = {
  56         { I2C_RESOURCE_BUILDER(0, 0) },
  57 #if     defined(CONFIG_ARCH_OMAP2) || defined(CONFIG_ARCH_OMAP3)
  58         { I2C_RESOURCE_BUILDER(OMAP2_I2C_BASE2, INT_24XX_I2C2_IRQ) },
  59 #endif
  60 #if     defined(CONFIG_ARCH_OMAP3)
  61         { I2C_RESOURCE_BUILDER(OMAP2_I2C_BASE3, INT_34XX_I2C3_IRQ) },
  62 #endif
  63 };
  64
  65 #define I2C_DEV_BUILDER(bus_id, res, data)              \
  66         {                                               \
  67                 .id     = (bus_id),                     \
  68                 .name   = name,                         \
  69                 .num_resources  = ARRAY_SIZE(res),      \
  70                 .resource       = (res),                \
  71                 .dev            = {                     \
  72                         .platform_data  = (data),       \
  73                 },                                      \
  74         }
  75
  76 static struct omap_i2c_bus_platform_data i2c_pdata[ARRAY_SIZE(i2c_resources)];
  77 static struct platform_device omap_i2c_devices[] = {
  78         I2C_DEV_BUILDER(1, i2c_resources[0], &i2c_pdata[0]),
  79 #if     defined(CONFIG_ARCH_OMAP2) || defined(CONFIG_ARCH_OMAP3)
  80         I2C_DEV_BUILDER(2, i2c_resources[1], &i2c_pdata[1]),
  81 #endif
  82 #if     defined(CONFIG_ARCH_OMAP3)
  83         I2C_DEV_BUILDER(3, i2c_resources[2], &i2c_pdata[2]),
  84 #endif
  85 };
  86
  87 #define OMAP_I2C_CMDLINE_SETUP  (BIT(31))
  88
  89 static int __init omap_i2c_nr_ports(void)
  90 {
  91         int ports = 0;
  92
  93         if (cpu_class_is_omap1())
  94                 ports = 1;
  95         else if (cpu_is_omap24xx())
  96                 ports = 2;
  97         else if (cpu_is_omap34xx())
  98                 ports = 3;
  99
 100         return ports;
 101 }
 102
 103 static int __init omap_i2c_add_bus(int bus_id)
 104 {
 105         struct platform_device *pdev;
 106         struct omap_i2c_bus_platform_data *pd;
 107         struct resource *res;
 108         resource_size_t base, irq;
 109
 110         pdev = &omap_i2c_devices[bus_id - 1];
 111         pd = pdev->dev.platform_data;
 112         if (bus_id == 1) {
 113                 res = pdev->resource;
 114                 if (cpu_class_is_omap1()) {
 115                         base = OMAP1_I2C_BASE;
 116                         irq = INT_I2C;
 117                 } else {
 118                         base = OMAP2_I2C_BASE1;
 119                         irq = INT_24XX_I2C1_IRQ;
 120                 }
 121                 res[0].start = base;
 122                 res[0].end = base + OMAP_I2C_SIZE;
 123                 res[1].start = irq;
 124         }
 125
 126         if (cpu_class_is_omap1())
 127                 omap1_i2c_mux_pins(bus_id);
 128         if (cpu_class_is_omap2())
 129                 omap2_i2c_mux_pins(bus_id);
 130
 131         /*
 132          * When waiting for completion of a i2c transfer, we need to
 133          * set a wake up latency constraint for the MPU. This is to
 134          * ensure quick enough wakeup from idle, when transfer
 135          * completes.
 136          */
 137         if (cpu_is_omap34xx())
 138                 pd->set_mpu_wkup_lat = omap_pm_set_max_mpu_wakeup_lat;
 139
 140         return platform_device_register(pdev);
 141 }
 142
 143 /**
 144  * omap_i2c_bus_setup - Process command line options for the I2C bus speed
 145  * @str: String of options
 146  *
 147  * This function allow to override the default I2C bus speed for given I2C
 148  * bus with a command line option.
 149  *
 150  * Format: i2c_bus=bus_id,clkrate (in kHz)
 151  *
 152  * Returns 1 on success, 0 otherwise.
 153  */
 154 static int __init omap_i2c_bus_setup(char *str)
 155 {
 156         int ports;
 157         int ints[3];
 158
 159         ports = omap_i2c_nr_ports();
 160         get_options(str, 3, ints);
 161         if (ints[0] < 2 || ints[1] < 1 || ints[1] > ports)
 162                 return 0;
 163         i2c_pdata[ints[1] - 1].clkrate = ints[2];
 164         i2c_pdata[ints[1] - 1].clkrate |= OMAP_I2C_CMDLINE_SETUP;
 165
 166         return 1;
 167 }
 168 __setup("i2c_bus=", omap_i2c_bus_setup);
 169
 170 /*
 171  * Register busses defined in command line but that are not registered with
 172  * omap_register_i2c_bus from board initialization code.
 173  */
 174 static int __init omap_register_i2c_bus_cmdline(void)
 175 {
 176         int i, err = 0;
 177
 178         for (i = 0; i < ARRAY_SIZE(i2c_pdata); i++)
 179                 if (i2c_pdata[i].clkrate & OMAP_I2C_CMDLINE_SETUP) {
 180                         i2c_pdata[i].clkrate &= ~OMAP_I2C_CMDLINE_SETUP;
 181                         err = omap_i2c_add_bus(i + 1);
 182                         if (err)
 183                                 goto out;
 184                 }
 185
 186 out:
 187         return err;
 188 }
 189 subsys_initcall(omap_register_i2c_bus_cmdline);
 190
 191 /**
 192  * omap_register_i2c_bus - register I2C bus with device descriptors
 193  * @bus_id: bus id counting from number 1
 194  * @clkrate: clock rate of the bus in kHz
 195  * @info: pointer into I2C device descriptor table or NULL
 196  * @len: number of descriptors in the table
 197  *
 198  * Returns 0 on success or an error code.
 199  */
 200 int __init omap_register_i2c_bus(int bus_id, u32 clkrate,
 201                           struct i2c_board_info const *info,
 202                           unsigned len)
 203 {
 204         int err;
 205
 206         BUG_ON(bus_id < 1 || bus_id > omap_i2c_nr_ports());
 207
 208         if (info) {
 209                 err = i2c_register_board_info(bus_id, info, len);
 210                 if (err)
 211                         return err;
 212         }
 213
 214         if (!i2c_pdata[bus_id - 1].clkrate)
 215                 i2c_pdata[bus_id - 1].clkrate = clkrate;
 216
 217         i2c_pdata[bus_id - 1].clkrate &= ~OMAP_I2C_CMDLINE_SETUP;
 218
 219         return omap_i2c_add_bus(bus_id);
 220 }