drivers/staging/media/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/mutex.h>
  28 #include <linux/uaccess.h>
  29
  30 #include "go7007-priv.h"
  31 #include "wis-i2c.h"
  32
  33 /********************* Driver for on-board I2C adapter *********************/
  34
  35 /* #define GO7007_I2C_DEBUG */
  36
  37 #define SPI_I2C_ADDR_BASE               0x1400
  38 #define STATUS_REG_ADDR                 (SPI_I2C_ADDR_BASE + 0x2)
  39 #define I2C_CTRL_REG_ADDR               (SPI_I2C_ADDR_BASE + 0x6)
  40 #define I2C_DEV_UP_ADDR_REG_ADDR        (SPI_I2C_ADDR_BASE + 0x7)
  41 #define I2C_LO_ADDR_REG_ADDR            (SPI_I2C_ADDR_BASE + 0x8)
  42 #define I2C_DATA_REG_ADDR               (SPI_I2C_ADDR_BASE + 0x9)
  43 #define I2C_CLKFREQ_REG_ADDR            (SPI_I2C_ADDR_BASE + 0xa)
  44
  45 #define I2C_STATE_MASK                  0x0007
  46 #define I2C_READ_READY_MASK             0x0008
  47
  48 /* There is only one I2C port on the TW2804 that feeds all four GO7007 VIPs
  49  * on the Adlink PCI-MPG24, so access is shared between all of them. */
  50 static DEFINE_MUTEX(adlink_mpg24_i2c_lock);
  51
  52 static int go7007_i2c_xfer(struct go7007 *go, u16 addr, int read,
  53                 u16 command, int flags, u8 *data)
  54 {
  55         int i, ret = -1;
  56         u16 val;
  57
  58         if (go->status == STATUS_SHUTDOWN)
  59                 return -1;
  60
  61 #ifdef GO7007_I2C_DEBUG
  62         if (read)
  63                 printk(KERN_DEBUG "go7007-i2c: reading 0x%02x on 0x%02x\n",
  64                         command, addr);
  65         else
  66                 printk(KERN_DEBUG
  67                         "go7007-i2c: writing 0x%02x to 0x%02x on 0x%02x\n",
  68                         *data, command, addr);
  69 #endif
  70
  71         mutex_lock(&go->hw_lock);
  72
  73         if (go->board_id == GO7007_BOARDID_ADLINK_MPG24) {
  74                 /* Bridge the I2C port on this GO7007 to the shared bus */
  75                 mutex_lock(&adlink_mpg24_i2c_lock);
  76                 go7007_write_addr(go, 0x3c82, 0x0020);
  77         }
  78
  79         /* Wait for I2C adapter to be ready */
  80         for (i = 0; i < 10; ++i) {
  81                 if (go7007_read_addr(go, STATUS_REG_ADDR, &val) < 0)
  82                         goto i2c_done;
  83                 if (!(val & I2C_STATE_MASK))
  84                         break;
  85                 msleep(100);
  86         }
  87         if (i == 10) {
  88                 printk(KERN_ERR "go7007-i2c: I2C adapter is hung\n");
  89                 goto i2c_done;
  90         }
  91
  92         /* Set target register (command) */
  93         go7007_write_addr(go, I2C_CTRL_REG_ADDR, flags);
  94         go7007_write_addr(go, I2C_LO_ADDR_REG_ADDR, command);
  95
  96         /* If we're writing, send the data and target address and we're done */
  97         if (!read) {
  98                 go7007_write_addr(go, I2C_DATA_REG_ADDR, *data);
  99                 go7007_write_addr(go, I2C_DEV_UP_ADDR_REG_ADDR,
 100                                         (addr << 9) | (command >> 8));
 101                 ret = 0;
 102                 goto i2c_done;
 103         }
 104
 105         /* Otherwise, we're reading.  First clear i2c_rx_data_rdy. */
 106         if (go7007_read_addr(go, I2C_DATA_REG_ADDR, &val) < 0)
 107                 goto i2c_done;
 108
 109         /* Send the target address plus read flag */
 110         go7007_write_addr(go, I2C_DEV_UP_ADDR_REG_ADDR,
 111                         (addr << 9) | 0x0100 | (command >> 8));
 112
 113         /* Wait for i2c_rx_data_rdy */
 114         for (i = 0; i < 10; ++i) {
 115                 if (go7007_read_addr(go, STATUS_REG_ADDR, &val) < 0)
 116                         goto i2c_done;
 117                 if (val & I2C_READ_READY_MASK)
 118                         break;
 119                 msleep(100);
 120         }
 121         if (i == 10) {
 122                 printk(KERN_ERR "go7007-i2c: I2C adapter is hung\n");
 123                 goto i2c_done;
 124         }
 125
 126         /* Retrieve the read byte */
 127         if (go7007_read_addr(go, I2C_DATA_REG_ADDR, &val) < 0)
 128                 goto i2c_done;
 129         *data = val;
 130         ret = 0;
 131
 132 i2c_done:
 133         if (go->board_id == GO7007_BOARDID_ADLINK_MPG24) {
 134                 /* Isolate the I2C port on this GO7007 from the shared bus */
 135                 go7007_write_addr(go, 0x3c82, 0x0000);
 136                 mutex_unlock(&adlink_mpg24_i2c_lock);
 137         }
 138         mutex_unlock(&go->hw_lock);
 139         return ret;
 140 }
 141
 142 static int go7007_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
 143                 unsigned short flags, char read_write,
 144                 u8 command, int size, union i2c_smbus_data *data)
 145 {
 146         struct go7007 *go = i2c_get_adapdata(adapter);
 147
 148         if (size != I2C_SMBUS_BYTE_DATA)
 149                 return -1;
 150         return go7007_i2c_xfer(go, addr, read_write == I2C_SMBUS_READ, command,
 151                         flags & I2C_CLIENT_SCCB ? 0x10 : 0x00, &data->byte);
 152 }
 153
 154 /* VERY LIMITED I2C master xfer function -- only needed because the
 155  * SMBus functions only support 8-bit commands and the SAA7135 uses
 156  * 16-bit commands.  The I2C interface on the GO7007, as limited as
 157  * it is, does support this mode. */
 158
 159 static int go7007_i2c_master_xfer(struct i2c_adapter *adapter,
 160                                         struct i2c_msg msgs[], int num)
 161 {
 162         struct go7007 *go = i2c_get_adapdata(adapter);
 163         int i;
 164
 165         for (i = 0; i < num; ++i) {
 166                 /* We can only do two things here -- write three bytes, or
 167                  * write two bytes and read one byte. */
 168                 if (msgs[i].len == 2) {
 169                         if (i + 1 == num || msgs[i].addr != msgs[i + 1].addr ||
 170                                         (msgs[i].flags & I2C_M_RD) ||
 171                                         !(msgs[i + 1].flags & I2C_M_RD) ||
 172                                         msgs[i + 1].len != 1)
 173                                 return -1;
 174                         if (go7007_i2c_xfer(go, msgs[i].addr, 1,
 175                                         (msgs[i].buf[0] << 8) | msgs[i].buf[1],
 176                                         0x01, &msgs[i + 1].buf[0]) < 0)
 177                                 return -1;
 178                         ++i;
 179                 } else if (msgs[i].len == 3) {
 180                         if (msgs[i].flags & I2C_M_RD)
 181                                 return -1;
 182                         if (msgs[i].len != 3)
 183                                 return -1;
 184                         if (go7007_i2c_xfer(go, msgs[i].addr, 0,
 185                                         (msgs[i].buf[0] << 8) | msgs[i].buf[1],
 186                                         0x01, &msgs[i].buf[2]) < 0)
 187                                 return -1;
 188                 } else
 189                         return -1;
 190         }
 191
 192         return 0;
 193 }
 194
 195 static u32 go7007_functionality(struct i2c_adapter *adapter)
 196 {
 197         return I2C_FUNC_SMBUS_BYTE_DATA;
 198 }
 199
 200 static struct i2c_algorithm go7007_algo = {
 201         .smbus_xfer     = go7007_smbus_xfer,
 202         .master_xfer    = go7007_i2c_master_xfer,
 203         .functionality  = go7007_functionality,
 204 };
 205
 206 static struct i2c_adapter go7007_adap_templ = {
 207         .owner                  = THIS_MODULE,
 208         .name                   = "WIS GO7007SB",
 209         .algo                   = &go7007_algo,
 210 };
 211
 212 int go7007_i2c_init(struct go7007 *go)
 213 {
 214         memcpy(&go->i2c_adapter, &go7007_adap_templ,
 215                         sizeof(go7007_adap_templ));
 216         go->i2c_adapter.dev.parent = go->dev;
 217         i2c_set_adapdata(&go->i2c_adapter, go);
 218         if (i2c_add_adapter(&go->i2c_adapter) < 0) {
 219                 printk(KERN_ERR
 220                         "go7007-i2c: error: i2c_add_adapter failed\n");
 221                 return -1;
 222         }
 223         return 0;
 224 }