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/mutex.h>
  28 #include <linux/uaccess.h>
  29 #include <asm/system.h>
  30
  31 #include "go7007-priv.h"
  32 #include "wis-i2c.h"
  33
  34 /********************* Driver for on-board I2C adapter *********************/
  35
  36 /* #define GO7007_I2C_DEBUG */
  37
  38 #define SPI_I2C_ADDR_BASE               0x1400
  39 #define STATUS_REG_ADDR                 (SPI_I2C_ADDR_BASE + 0x2)
  40 #define I2C_CTRL_REG_ADDR               (SPI_I2C_ADDR_BASE + 0x6)
  41 #define I2C_DEV_UP_ADDR_REG_ADDR        (SPI_I2C_ADDR_BASE + 0x7)
  42 #define I2C_LO_ADDR_REG_ADDR            (SPI_I2C_ADDR_BASE + 0x8)
  43 #define I2C_DATA_REG_ADDR               (SPI_I2C_ADDR_BASE + 0x9)
  44 #define I2C_CLKFREQ_REG_ADDR            (SPI_I2C_ADDR_BASE + 0xa)
  45
  46 #define I2C_STATE_MASK                  0x0007
  47 #define I2C_READ_READY_MASK             0x0008
  48
  49 /* There is only one I2C port on the TW2804 that feeds all four GO7007 VIPs
  50  * on the Adlink PCI-MPG24, so access is shared between all of them. */
  51 static DEFINE_MUTEX(adlink_mpg24_i2c_lock);
  52
  53 static int go7007_i2c_xfer(struct go7007 *go, u16 addr, int read,
  54                 u16 command, int flags, u8 *data)
  55 {
  56         int i, ret = -1;
  57         u16 val;
  58
  59         if (go->status == STATUS_SHUTDOWN)
  60                 return -1;
  61
  62 #ifdef GO7007_I2C_DEBUG
  63         if (read)
  64                 printk(KERN_DEBUG "go7007-i2c: reading 0x%02x on 0x%02x\n",
  65                         command, addr);
  66         else
  67                 printk(KERN_DEBUG
  68                         "go7007-i2c: writing 0x%02x to 0x%02x on 0x%02x\n",
  69                         *data, command, addr);
  70 #endif
  71
  72         mutex_lock(&go->hw_lock);
  73
  74         if (go->board_id == GO7007_BOARDID_ADLINK_MPG24) {
  75                 /* Bridge the I2C port on this GO7007 to the shared bus */
  76                 mutex_lock(&adlink_mpg24_i2c_lock);
  77                 go7007_write_addr(go, 0x3c82, 0x0020);
  78         }
  79
  80         /* Wait for I2C adapter to be ready */
  81         for (i = 0; i < 10; ++i) {
  82                 if (go7007_read_addr(go, STATUS_REG_ADDR, &val) < 0)
  83                         goto i2c_done;
  84                 if (!(val & I2C_STATE_MASK))
  85                         break;
  86                 msleep(100);
  87         }
  88         if (i == 10) {
  89                 printk(KERN_ERR "go7007-i2c: I2C adapter is hung\n");
  90                 goto i2c_done;
  91         }
  92
  93         /* Set target register (command) */
  94         go7007_write_addr(go, I2C_CTRL_REG_ADDR, flags);
  95         go7007_write_addr(go, I2C_LO_ADDR_REG_ADDR, command);
  96
  97         /* If we're writing, send the data and target address and we're done */
  98         if (!read) {
  99                 go7007_write_addr(go, I2C_DATA_REG_ADDR, *data);
 100                 go7007_write_addr(go, I2C_DEV_UP_ADDR_REG_ADDR,
 101                                         (addr << 9) | (command >> 8));
 102                 ret = 0;
 103                 goto i2c_done;
 104         }
 105
 106         /* Otherwise, we're reading.  First clear i2c_rx_data_rdy. */
 107         if (go7007_read_addr(go, I2C_DATA_REG_ADDR, &val) < 0)
 108                 goto i2c_done;
 109
 110         /* Send the target address plus read flag */
 111         go7007_write_addr(go, I2C_DEV_UP_ADDR_REG_ADDR,
 112                         (addr << 9) | 0x0100 | (command >> 8));
 113
 114         /* Wait for i2c_rx_data_rdy */
 115         for (i = 0; i < 10; ++i) {
 116                 if (go7007_read_addr(go, STATUS_REG_ADDR, &val) < 0)
 117                         goto i2c_done;
 118                 if (val & I2C_READ_READY_MASK)
 119                         break;
 120                 msleep(100);
 121         }
 122         if (i == 10) {
 123                 printk(KERN_ERR "go7007-i2c: I2C adapter is hung\n");
 124                 goto i2c_done;
 125         }
 126
 127         /* Retrieve the read byte */
 128         if (go7007_read_addr(go, I2C_DATA_REG_ADDR, &val) < 0)
 129                 goto i2c_done;
 130         *data = val;
 131         ret = 0;
 132
 133 i2c_done:
 134         if (go->board_id == GO7007_BOARDID_ADLINK_MPG24) {
 135                 /* Isolate the I2C port on this GO7007 from the shared bus */
 136                 go7007_write_addr(go, 0x3c82, 0x0000);
 137                 mutex_unlock(&adlink_mpg24_i2c_lock);
 138         }
 139         mutex_unlock(&go->hw_lock);
 140         return ret;
 141 }
 142
 143 static int go7007_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
 144                 unsigned short flags, char read_write,
 145                 u8 command, int size, union i2c_smbus_data *data)
 146 {
 147         struct go7007 *go = i2c_get_adapdata(adapter);
 148
 149         if (size != I2C_SMBUS_BYTE_DATA)
 150                 return -1;
 151         return go7007_i2c_xfer(go, addr, read_write == I2C_SMBUS_READ, command,
 152                         flags & I2C_CLIENT_SCCB ? 0x10 : 0x00, &data->byte);
 153 }
 154
 155 /* VERY LIMITED I2C master xfer function -- only needed because the
 156  * SMBus functions only support 8-bit commands and the SAA7135 uses
 157  * 16-bit commands.  The I2C interface on the GO7007, as limited as
 158  * it is, does support this mode. */
 159
 160 static int go7007_i2c_master_xfer(struct i2c_adapter *adapter,
 161                                         struct i2c_msg msgs[], int num)
 162 {
 163         struct go7007 *go = i2c_get_adapdata(adapter);
 164         int i;
 165
 166         for (i = 0; i < num; ++i) {
 167                 /* We can only do two things here -- write three bytes, or
 168                  * write two bytes and read one byte. */
 169                 if (msgs[i].len == 2) {
 170                         if (i + 1 == num || msgs[i].addr != msgs[i + 1].addr ||
 171                                         (msgs[i].flags & I2C_M_RD) ||
 172                                         !(msgs[i + 1].flags & I2C_M_RD) ||
 173                                         msgs[i + 1].len != 1)
 174                                 return -1;
 175                         if (go7007_i2c_xfer(go, msgs[i].addr, 1,
 176                                         (msgs[i].buf[0] << 8) | msgs[i].buf[1],
 177                                         0x01, &msgs[i + 1].buf[0]) < 0)
 178                                 return -1;
 179                         ++i;
 180                 } else if (msgs[i].len == 3) {
 181                         if (msgs[i].flags & I2C_M_RD)
 182                                 return -1;
 183                         if (msgs[i].len != 3)
 184                                 return -1;
 185                         if (go7007_i2c_xfer(go, msgs[i].addr, 0,
 186                                         (msgs[i].buf[0] << 8) | msgs[i].buf[1],
 187                                         0x01, &msgs[i].buf[2]) < 0)
 188                                 return -1;
 189                 } else
 190                         return -1;
 191         }
 192
 193         return 0;
 194 }
 195
 196 static u32 go7007_functionality(struct i2c_adapter *adapter)
 197 {
 198         return I2C_FUNC_SMBUS_BYTE_DATA;
 199 }
 200
 201 static struct i2c_algorithm go7007_algo = {
 202         .smbus_xfer     = go7007_smbus_xfer,
 203         .master_xfer    = go7007_i2c_master_xfer,
 204         .functionality  = go7007_functionality,
 205 };
 206
 207 static struct i2c_adapter go7007_adap_templ = {
 208         .owner                  = THIS_MODULE,
 209         .name                   = "WIS GO7007SB",
 210         .algo                   = &go7007_algo,
 211 };
 212
 213 int go7007_i2c_init(struct go7007 *go)
 214 {
 215         memcpy(&go->i2c_adapter, &go7007_adap_templ,
 216                         sizeof(go7007_adap_templ));
 217         go->i2c_adapter.dev.parent = go->dev;
 218         i2c_set_adapdata(&go->i2c_adapter, go);
 219         if (i2c_add_adapter(&go->i2c_adapter) < 0) {
 220                 printk(KERN_ERR
 221                         "go7007-i2c: error: i2c_add_adapter failed\n");
 222                 return -1;
 223         }
 224         return 0;
 225 }