drivers/media/usb/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
  14 #include <linux/module.h>
  15 #include <linux/delay.h>
  16 #include <linux/sched.h>
  17 #include <linux/list.h>
  18 #include <linux/unistd.h>
  19 #include <linux/time.h>
  20 #include <linux/device.h>
  21 #include <linux/i2c.h>
  22 #include <linux/mutex.h>
  23 #include <linux/uaccess.h>
  24
  25 #include "go7007-priv.h"
  26
  27 /********************* Driver for on-board I2C adapter *********************/
  28
  29 /* #define GO7007_I2C_DEBUG */
  30
  31 #define SPI_I2C_ADDR_BASE               0x1400
  32 #define STATUS_REG_ADDR                 (SPI_I2C_ADDR_BASE + 0x2)
  33 #define I2C_CTRL_REG_ADDR               (SPI_I2C_ADDR_BASE + 0x6)
  34 #define I2C_DEV_UP_ADDR_REG_ADDR        (SPI_I2C_ADDR_BASE + 0x7)
  35 #define I2C_LO_ADDR_REG_ADDR            (SPI_I2C_ADDR_BASE + 0x8)
  36 #define I2C_DATA_REG_ADDR               (SPI_I2C_ADDR_BASE + 0x9)
  37 #define I2C_CLKFREQ_REG_ADDR            (SPI_I2C_ADDR_BASE + 0xa)
  38
  39 #define I2C_STATE_MASK                  0x0007
  40 #define I2C_READ_READY_MASK             0x0008
  41
  42 /* There is only one I2C port on the TW2804 that feeds all four GO7007 VIPs
  43  * on the Adlink PCI-MPG24, so access is shared between all of them. */
  44 static DEFINE_MUTEX(adlink_mpg24_i2c_lock);
  45
  46 static int go7007_i2c_xfer(struct go7007 *go, u16 addr, int read,
  47                 u16 command, int flags, u8 *data)
  48 {
  49         int i, ret = -EIO;
  50         u16 val;
  51
  52         if (go->status == STATUS_SHUTDOWN)
  53                 return -ENODEV;
  54
  55 #ifdef GO7007_I2C_DEBUG
  56         if (read)
  57                 dev_dbg(go->dev, "go7007-i2c: reading 0x%02x on 0x%02x\n",
  58                         command, addr);
  59         else
  60                 dev_dbg(go->dev,
  61                         "go7007-i2c: writing 0x%02x to 0x%02x on 0x%02x\n",
  62                         *data, command, addr);
  63 #endif
  64
  65         mutex_lock(&go->hw_lock);
  66
  67         if (go->board_id == GO7007_BOARDID_ADLINK_MPG24) {
  68                 /* Bridge the I2C port on this GO7007 to the shared bus */
  69                 mutex_lock(&adlink_mpg24_i2c_lock);
  70                 go7007_write_addr(go, 0x3c82, 0x0020);
  71         }
  72
  73         /* Wait for I2C adapter to be ready */
  74         for (i = 0; i < 10; ++i) {
  75                 if (go7007_read_addr(go, STATUS_REG_ADDR, &val) < 0)
  76                         goto i2c_done;
  77                 if (!(val & I2C_STATE_MASK))
  78                         break;
  79                 msleep(100);
  80         }
  81         if (i == 10) {
  82                 dev_err(go->dev, "go7007-i2c: I2C adapter is hung\n");
  83                 goto i2c_done;
  84         }
  85
  86         /* Set target register (command) */
  87         go7007_write_addr(go, I2C_CTRL_REG_ADDR, flags);
  88         go7007_write_addr(go, I2C_LO_ADDR_REG_ADDR, command);
  89
  90         /* If we're writing, send the data and target address and we're done */
  91         if (!read) {
  92                 go7007_write_addr(go, I2C_DATA_REG_ADDR, *data);
  93                 go7007_write_addr(go, I2C_DEV_UP_ADDR_REG_ADDR,
  94                                         (addr << 9) | (command >> 8));
  95                 ret = 0;
  96                 goto i2c_done;
  97         }
  98
  99         /* Otherwise, we're reading.  First clear i2c_rx_data_rdy. */
 100         if (go7007_read_addr(go, I2C_DATA_REG_ADDR, &val) < 0)
 101                 goto i2c_done;
 102
 103         /* Send the target address plus read flag */
 104         go7007_write_addr(go, I2C_DEV_UP_ADDR_REG_ADDR,
 105                         (addr << 9) | 0x0100 | (command >> 8));
 106
 107         /* Wait for i2c_rx_data_rdy */
 108         for (i = 0; i < 10; ++i) {
 109                 if (go7007_read_addr(go, STATUS_REG_ADDR, &val) < 0)
 110                         goto i2c_done;
 111                 if (val & I2C_READ_READY_MASK)
 112                         break;
 113                 msleep(100);
 114         }
 115         if (i == 10) {
 116                 dev_err(go->dev, "go7007-i2c: I2C adapter is hung\n");
 117                 goto i2c_done;
 118         }
 119
 120         /* Retrieve the read byte */
 121         if (go7007_read_addr(go, I2C_DATA_REG_ADDR, &val) < 0)
 122                 goto i2c_done;
 123         *data = val;
 124         ret = 0;
 125
 126 i2c_done:
 127         if (go->board_id == GO7007_BOARDID_ADLINK_MPG24) {
 128                 /* Isolate the I2C port on this GO7007 from the shared bus */
 129                 go7007_write_addr(go, 0x3c82, 0x0000);
 130                 mutex_unlock(&adlink_mpg24_i2c_lock);
 131         }
 132         mutex_unlock(&go->hw_lock);
 133         return ret;
 134 }
 135
 136 static int go7007_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
 137                 unsigned short flags, char read_write,
 138                 u8 command, int size, union i2c_smbus_data *data)
 139 {
 140         struct go7007 *go = i2c_get_adapdata(adapter);
 141
 142         if (size != I2C_SMBUS_BYTE_DATA)
 143                 return -EIO;
 144         return go7007_i2c_xfer(go, addr, read_write == I2C_SMBUS_READ, command,
 145                         flags & I2C_CLIENT_SCCB ? 0x10 : 0x00, &data->byte);
 146 }
 147
 148 /* VERY LIMITED I2C master xfer function -- only needed because the
 149  * SMBus functions only support 8-bit commands and the SAA7135 uses
 150  * 16-bit commands.  The I2C interface on the GO7007, as limited as
 151  * it is, does support this mode. */
 152
 153 static int go7007_i2c_master_xfer(struct i2c_adapter *adapter,
 154                                         struct i2c_msg msgs[], int num)
 155 {
 156         struct go7007 *go = i2c_get_adapdata(adapter);
 157         int i;
 158
 159         for (i = 0; i < num; ++i) {
 160                 /* We can only do two things here -- write three bytes, or
 161                  * write two bytes and read one byte. */
 162                 if (msgs[i].len == 2) {
 163                         if (i + 1 == num || msgs[i].addr != msgs[i + 1].addr ||
 164                                         (msgs[i].flags & I2C_M_RD) ||
 165                                         !(msgs[i + 1].flags & I2C_M_RD) ||
 166                                         msgs[i + 1].len != 1)
 167                                 return -EIO;
 168                         if (go7007_i2c_xfer(go, msgs[i].addr, 1,
 169                                         (msgs[i].buf[0] << 8) | msgs[i].buf[1],
 170                                         0x01, &msgs[i + 1].buf[0]) < 0)
 171                                 return -EIO;
 172                         ++i;
 173                 } else if (msgs[i].len == 3) {
 174                         if (msgs[i].flags & I2C_M_RD)
 175                                 return -EIO;
 176                         if (msgs[i].len != 3)
 177                                 return -EIO;
 178                         if (go7007_i2c_xfer(go, msgs[i].addr, 0,
 179                                         (msgs[i].buf[0] << 8) | msgs[i].buf[1],
 180                                         0x01, &msgs[i].buf[2]) < 0)
 181                                 return -EIO;
 182                 } else
 183                         return -EIO;
 184         }
 185
 186         return num;
 187 }
 188
 189 static u32 go7007_functionality(struct i2c_adapter *adapter)
 190 {
 191         return I2C_FUNC_SMBUS_BYTE_DATA;
 192 }
 193
 194 static struct i2c_algorithm go7007_algo = {
 195         .smbus_xfer     = go7007_smbus_xfer,
 196         .master_xfer    = go7007_i2c_master_xfer,
 197         .functionality  = go7007_functionality,
 198 };
 199
 200 static struct i2c_adapter go7007_adap_templ = {
 201         .owner                  = THIS_MODULE,
 202         .name                   = "WIS GO7007SB",
 203         .algo                   = &go7007_algo,
 204 };
 205
 206 int go7007_i2c_init(struct go7007 *go)
 207 {
 208         memcpy(&go->i2c_adapter, &go7007_adap_templ,
 209                         sizeof(go7007_adap_templ));
 210         go->i2c_adapter.dev.parent = go->dev;
 211         i2c_set_adapdata(&go->i2c_adapter, go);
 212         if (i2c_add_adapter(&go->i2c_adapter) < 0) {
 213                 dev_err(go->dev,
 214                         "go7007-i2c: error: i2c_add_adapter failed\n");
 215                 return -1;
 216         }
 217         return 0;
 218 }