drivers/staging/go7007/go7007-i2c.c

   1 /*
   2  * Copyright (C) 2005-2006 Micronas USA Inc.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License (Version 2) as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this program; if not, write to the Free Software Foundation,
  15  * Inc., 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
  16  */
  17
  18 #include <linux/version.h>
  19 #include <linux/module.h>
  20 #include <linux/init.h>
  21 #include <linux/delay.h>
  22 #include <linux/sched.h>
  23 #include <linux/list.h>
  24 #include <linux/unistd.h>
  25 #include <linux/time.h>
  26 #include <linux/device.h>
  27 #include <linux/i2c.h>
  28 #include <linux/semaphore.h>
  29 #include <linux/uaccess.h>
  30 #include <asm/system.h>
  31
  32 #include "go7007-priv.h"
  33 #include "wis-i2c.h"
  34
  35 /************** Registration interface for I2C client drivers **************/
  36
  37 /* Since there's no way to auto-probe the I2C devices connected to the I2C
  38  * bus on the go7007, we have this silly little registration system that
  39  * client drivers can use to register their I2C driver ID and their
  40  * detect_client function (the one that's normally passed to i2c_probe).
  41  *
  42  * When a new go7007 device is connected, we can look up in a board info
  43  * table by the USB or PCI vendor/product/revision ID to determine
  44  * which I2C client module to load.  The client driver module will register
  45  * itself here, and then we can call the registered detect_client function
  46  * to force-load a new client at the address listed in the board info table.
  47  *
  48  * Really the I2C subsystem should have a way to force-load I2C client
  49  * drivers when we have a priori knowledge of what's on the bus, especially
  50  * since the existing I2C auto-probe mechanism is so hokey, but we'll use
  51  * our own mechanism for the time being. */
  52
  53 struct wis_i2c_client_driver {
  54         unsigned int id;
  55         found_proc found_proc;
  56         struct list_head list;
  57 };
  58
  59 static LIST_HEAD(i2c_client_drivers);
  60 static DECLARE_MUTEX(i2c_client_driver_list_lock);
  61
  62 /* Client drivers register here by their I2C driver ID */
  63 int wis_i2c_add_driver(unsigned int id, found_proc found_proc)
  64 {
  65         struct wis_i2c_client_driver *driver;
  66
  67         driver = kmalloc(sizeof(struct wis_i2c_client_driver), GFP_KERNEL);
  68         if (driver == NULL)
  69                 return -ENOMEM;
  70         driver->id = id;
  71         driver->found_proc = found_proc;
  72
  73         down(&i2c_client_driver_list_lock);
  74         list_add_tail(&driver->list, &i2c_client_drivers);
  75         up(&i2c_client_driver_list_lock);
  76
  77         return 0;
  78 }
  79 EXPORT_SYMBOL(wis_i2c_add_driver);
  80
  81 void wis_i2c_del_driver(found_proc found_proc)
  82 {
  83         struct wis_i2c_client_driver *driver, *next;
  84
  85         down(&i2c_client_driver_list_lock);
  86         list_for_each_entry_safe(driver, next, &i2c_client_drivers, list)
  87                 if (driver->found_proc == found_proc) {
  88                         list_del(&driver->list);
  89                         kfree(driver);
  90                 }
  91         up(&i2c_client_driver_list_lock);
  92 }
  93 EXPORT_SYMBOL(wis_i2c_del_driver);
  94
  95 /* The main go7007 driver calls this to instantiate a client by driver
  96  * ID and bus address, which are both stored in the board info table */
  97 int wis_i2c_probe_device(struct i2c_adapter *adapter,
  98                                 unsigned int id, int addr)
  99 {
 100         struct wis_i2c_client_driver *driver;
 101         int found = 0;
 102
 103         if (addr < 0 || addr > 0x7f)
 104                 return -1;
 105         down(&i2c_client_driver_list_lock);
 106         list_for_each_entry(driver, &i2c_client_drivers, list)
 107                 if (driver->id == id) {
 108                         if (driver->found_proc(adapter, addr, 0) == 0)
 109                                 found = 1;
 110                         break;
 111                 }
 112         up(&i2c_client_driver_list_lock);
 113         return found;
 114 }
 115
 116 /********************* Driver for on-board I2C adapter *********************/
 117
 118 /* #define GO7007_I2C_DEBUG */
 119
 120 #define SPI_I2C_ADDR_BASE               0x1400
 121 #define STATUS_REG_ADDR                 (SPI_I2C_ADDR_BASE + 0x2)
 122 #define I2C_CTRL_REG_ADDR               (SPI_I2C_ADDR_BASE + 0x6)
 123 #define I2C_DEV_UP_ADDR_REG_ADDR        (SPI_I2C_ADDR_BASE + 0x7)
 124 #define I2C_LO_ADDR_REG_ADDR            (SPI_I2C_ADDR_BASE + 0x8)
 125 #define I2C_DATA_REG_ADDR               (SPI_I2C_ADDR_BASE + 0x9)
 126 #define I2C_CLKFREQ_REG_ADDR            (SPI_I2C_ADDR_BASE + 0xa)
 127
 128 #define I2C_STATE_MASK                  0x0007
 129 #define I2C_READ_READY_MASK             0x0008
 130
 131 /* There is only one I2C port on the TW2804 that feeds all four GO7007 VIPs
 132  * on the Adlink PCI-MPG24, so access is shared between all of them. */
 133 static DECLARE_MUTEX(adlink_mpg24_i2c_lock);
 134
 135 static int go7007_i2c_xfer(struct go7007 *go, u16 addr, int read,
 136                 u16 command, int flags, u8 *data)
 137 {
 138         int i, ret = -1;
 139         u16 val;
 140
 141         if (go->status == STATUS_SHUTDOWN)
 142                 return -1;
 143
 144 #ifdef GO7007_I2C_DEBUG
 145         if (read)
 146                 printk(KERN_DEBUG "go7007-i2c: reading 0x%02x on 0x%02x\n",
 147                         command, addr);
 148         else
 149                 printk(KERN_DEBUG
 150                         "go7007-i2c: writing 0x%02x to 0x%02x on 0x%02x\n",
 151                         *data, command, addr);
 152 #endif
 153
 154         down(&go->hw_lock);
 155
 156         if (go->board_id == GO7007_BOARDID_ADLINK_MPG24) {
 157                 /* Bridge the I2C port on this GO7007 to the shared bus */
 158                 down(&adlink_mpg24_i2c_lock);
 159                 go7007_write_addr(go, 0x3c82, 0x0020);
 160         }
 161
 162         /* Wait for I2C adapter to be ready */
 163         for (i = 0; i < 10; ++i) {
 164                 if (go7007_read_addr(go, STATUS_REG_ADDR, &val) < 0)
 165                         goto i2c_done;
 166                 if (!(val & I2C_STATE_MASK))
 167                         break;
 168                 msleep(100);
 169         }
 170         if (i == 10) {
 171                 printk(KERN_ERR "go7007-i2c: I2C adapter is hung\n");
 172                 goto i2c_done;
 173         }
 174
 175         /* Set target register (command) */
 176         go7007_write_addr(go, I2C_CTRL_REG_ADDR, flags);
 177         go7007_write_addr(go, I2C_LO_ADDR_REG_ADDR, command);
 178
 179         /* If we're writing, send the data and target address and we're done */
 180         if (!read) {
 181                 go7007_write_addr(go, I2C_DATA_REG_ADDR, *data);
 182                 go7007_write_addr(go, I2C_DEV_UP_ADDR_REG_ADDR,
 183                                         (addr << 9) | (command >> 8));
 184                 ret = 0;
 185                 goto i2c_done;
 186         }
 187
 188         /* Otherwise, we're reading.  First clear i2c_rx_data_rdy. */
 189         if (go7007_read_addr(go, I2C_DATA_REG_ADDR, &val) < 0)
 190                 goto i2c_done;
 191
 192         /* Send the target address plus read flag */
 193         go7007_write_addr(go, I2C_DEV_UP_ADDR_REG_ADDR,
 194                         (addr << 9) | 0x0100 | (command >> 8));
 195
 196         /* Wait for i2c_rx_data_rdy */
 197         for (i = 0; i < 10; ++i) {
 198                 if (go7007_read_addr(go, STATUS_REG_ADDR, &val) < 0)
 199                         goto i2c_done;
 200                 if (val & I2C_READ_READY_MASK)
 201                         break;
 202                 msleep(100);
 203         }
 204         if (i == 10) {
 205                 printk(KERN_ERR "go7007-i2c: I2C adapter is hung\n");
 206                 goto i2c_done;
 207         }
 208
 209         /* Retrieve the read byte */
 210         if (go7007_read_addr(go, I2C_DATA_REG_ADDR, &val) < 0)
 211                 goto i2c_done;
 212         *data = val;
 213         ret = 0;
 214
 215 i2c_done:
 216         if (go->board_id == GO7007_BOARDID_ADLINK_MPG24) {
 217                 /* Isolate the I2C port on this GO7007 from the shared bus */
 218                 go7007_write_addr(go, 0x3c82, 0x0000);
 219                 up(&adlink_mpg24_i2c_lock);
 220         }
 221         up(&go->hw_lock);
 222         return ret;
 223 }
 224
 225 static int go7007_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
 226                 unsigned short flags, char read_write,
 227                 u8 command, int size, union i2c_smbus_data *data)
 228 {
 229         struct go7007 *go = i2c_get_adapdata(adapter);
 230
 231         if (size != I2C_SMBUS_BYTE_DATA)
 232                 return -1;
 233         return go7007_i2c_xfer(go, addr, read_write == I2C_SMBUS_READ, command,
 234                         flags & I2C_CLIENT_SCCB ? 0x10 : 0x00, &data->byte);
 235 }
 236
 237 /* VERY LIMITED I2C master xfer function -- only needed because the
 238  * SMBus functions only support 8-bit commands and the SAA7135 uses
 239  * 16-bit commands.  The I2C interface on the GO7007, as limited as
 240  * it is, does support this mode. */
 241
 242 static int go7007_i2c_master_xfer(struct i2c_adapter *adapter,
 243                                         struct i2c_msg msgs[], int num)
 244 {
 245         struct go7007 *go = i2c_get_adapdata(adapter);
 246         int i;
 247
 248         for (i = 0; i < num; ++i) {
 249                 /* We can only do two things here -- write three bytes, or
 250                  * write two bytes and read one byte. */
 251                 if (msgs[i].len == 2) {
 252                         if (i + 1 == num || msgs[i].addr != msgs[i + 1].addr ||
 253                                         (msgs[i].flags & I2C_M_RD) ||
 254                                         !(msgs[i + 1].flags & I2C_M_RD) ||
 255                                         msgs[i + 1].len != 1)
 256                                 return -1;
 257                         if (go7007_i2c_xfer(go, msgs[i].addr, 1,
 258                                         (msgs[i].buf[0] << 8) | msgs[i].buf[1],
 259                                         0x01, &msgs[i + 1].buf[0]) < 0)
 260                                 return -1;
 261                         ++i;
 262                 } else if (msgs[i].len == 3) {
 263                         if (msgs[i].flags & I2C_M_RD)
 264                                 return -1;
 265                         if (msgs[i].len != 3)
 266                                 return -1;
 267                         if (go7007_i2c_xfer(go, msgs[i].addr, 0,
 268                                         (msgs[i].buf[0] << 8) | msgs[i].buf[1],
 269                                         0x01, &msgs[i].buf[2]) < 0)
 270                                 return -1;
 271                 } else
 272                         return -1;
 273         }
 274
 275         return 0;
 276 }
 277
 278 static u32 go7007_functionality(struct i2c_adapter *adapter)
 279 {
 280         return I2C_FUNC_SMBUS_BYTE_DATA;
 281 }
 282
 283 static struct i2c_algorithm go7007_algo = {
 284         .smbus_xfer     = go7007_smbus_xfer,
 285         .master_xfer    = go7007_i2c_master_xfer,
 286         .functionality  = go7007_functionality,
 287 };
 288
 289 static struct i2c_adapter go7007_adap_templ = {
 290         .owner                  = THIS_MODULE,
 291         .class                  = I2C_CLASS_TV_ANALOG,
 292         .name                   = "WIS GO7007SB",
 293         .id                     = I2C_ALGO_GO7007,
 294         .algo                   = &go7007_algo,
 295 };
 296
 297 int go7007_i2c_init(struct go7007 *go)
 298 {
 299         memcpy(&go->i2c_adapter, &go7007_adap_templ,
 300                         sizeof(go7007_adap_templ));
 301         go->i2c_adapter.dev.parent = go->dev;
 302         i2c_set_adapdata(&go->i2c_adapter, go);
 303         if (i2c_add_adapter(&go->i2c_adapter) < 0) {
 304                 printk(KERN_ERR
 305                         "go7007-i2c: error: i2c_add_adapter failed\n");
 306                 return -1;
 307         }
 308         return 0;
 309 }