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