drivers/media/usb/go7007/go7007-i2c.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2005-2006 Micronas USA Inc.
   4  */
   5
   6 #include <linux/module.h>
   7 #include <linux/delay.h>
   8 #include <linux/sched.h>
   9 #include <linux/list.h>
  10 #include <linux/unistd.h>
  11 #include <linux/time.h>
  12 #include <linux/device.h>
  13 #include <linux/i2c.h>
  14 #include <linux/mutex.h>
  15 #include <linux/uaccess.h>
  16
  17 #include "go7007-priv.h"
  18
  19 /********************* Driver for on-board I2C adapter *********************/
  20
  21 /* #define GO7007_I2C_DEBUG */
  22
  23 #define SPI_I2C_ADDR_BASE               0x1400
  24 #define STATUS_REG_ADDR                 (SPI_I2C_ADDR_BASE + 0x2)
  25 #define I2C_CTRL_REG_ADDR               (SPI_I2C_ADDR_BASE + 0x6)
  26 #define I2C_DEV_UP_ADDR_REG_ADDR        (SPI_I2C_ADDR_BASE + 0x7)
  27 #define I2C_LO_ADDR_REG_ADDR            (SPI_I2C_ADDR_BASE + 0x8)
  28 #define I2C_DATA_REG_ADDR               (SPI_I2C_ADDR_BASE + 0x9)
  29 #define I2C_CLKFREQ_REG_ADDR            (SPI_I2C_ADDR_BASE + 0xa)
  30
  31 #define I2C_STATE_MASK                  0x0007
  32 #define I2C_READ_READY_MASK             0x0008
  33
  34 /* There is only one I2C port on the TW2804 that feeds all four GO7007 VIPs
  35  * on the Adlink PCI-MPG24, so access is shared between all of them. */
  36 static DEFINE_MUTEX(adlink_mpg24_i2c_mutex);
  37
  38 static inline void adlink_mpg24_i2c_lock(struct go7007 *go)
  39 {
  40         /* Bridge the I2C port on this GO7007 to the shared bus */
  41         mutex_lock(&adlink_mpg24_i2c_mutex);
  42         go7007_write_addr(go, 0x3c82, 0x0020);
  43 }
  44
  45 static inline void adlink_mpg24_i2c_unlock(struct go7007 *go)
  46 {
  47         /* Isolate the I2C port on this GO7007 from the shared bus */
  48         go7007_write_addr(go, 0x3c82, 0x0000);
  49         mutex_unlock(&adlink_mpg24_i2c_mutex);
  50 }
  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 = -EIO;
  56         u16 val;
  57
  58         if (go->status == STATUS_SHUTDOWN)
  59                 return -ENODEV;
  60
  61 #ifdef GO7007_I2C_DEBUG
  62         if (read)
  63                 dev_dbg(go->dev, "go7007-i2c: reading 0x%02x on 0x%02x\n",
  64                         command, addr);
  65         else
  66                 dev_dbg(go->dev,
  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                 adlink_mpg24_i2c_lock(go);
  75
  76         /* Wait for I2C adapter to be ready */
  77         for (i = 0; i < 10; ++i) {
  78                 if (go7007_read_addr(go, STATUS_REG_ADDR, &val) < 0)
  79                         goto i2c_done;
  80                 if (!(val & I2C_STATE_MASK))
  81                         break;
  82                 msleep(100);
  83         }
  84         if (i == 10) {
  85                 dev_err(go->dev, "go7007-i2c: I2C adapter is hung\n");
  86                 goto i2c_done;
  87         }
  88
  89         /* Set target register (command) */
  90         go7007_write_addr(go, I2C_CTRL_REG_ADDR, flags);
  91         go7007_write_addr(go, I2C_LO_ADDR_REG_ADDR, command);
  92
  93         /* If we're writing, send the data and target address and we're done */
  94         if (!read) {
  95                 go7007_write_addr(go, I2C_DATA_REG_ADDR, *data);
  96                 go7007_write_addr(go, I2C_DEV_UP_ADDR_REG_ADDR,
  97                                         (addr << 9) | (command >> 8));
  98                 ret = 0;
  99                 goto i2c_done;
 100         }
 101
 102         /* Otherwise, we're reading.  First clear i2c_rx_data_rdy. */
 103         if (go7007_read_addr(go, I2C_DATA_REG_ADDR, &val) < 0)
 104                 goto i2c_done;
 105
 106         /* Send the target address plus read flag */
 107         go7007_write_addr(go, I2C_DEV_UP_ADDR_REG_ADDR,
 108                         (addr << 9) | 0x0100 | (command >> 8));
 109
 110         /* Wait for i2c_rx_data_rdy */
 111         for (i = 0; i < 10; ++i) {
 112                 if (go7007_read_addr(go, STATUS_REG_ADDR, &val) < 0)
 113                         goto i2c_done;
 114                 if (val & I2C_READ_READY_MASK)
 115                         break;
 116                 msleep(100);
 117         }
 118         if (i == 10) {
 119                 dev_err(go->dev, "go7007-i2c: I2C adapter is hung\n");
 120                 goto i2c_done;
 121         }
 122
 123         /* Retrieve the read byte */
 124         if (go7007_read_addr(go, I2C_DATA_REG_ADDR, &val) < 0)
 125                 goto i2c_done;
 126         *data = val;
 127         ret = 0;
 128
 129 i2c_done:
 130         if (go->board_id == GO7007_BOARDID_ADLINK_MPG24)
 131                 adlink_mpg24_i2c_unlock(go);
 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 (go7007_i2c_xfer(go, msgs[i].addr, 0,
 177                                         (msgs[i].buf[0] << 8) | msgs[i].buf[1],
 178                                         0x01, &msgs[i].buf[2]) < 0)
 179                                 return -EIO;
 180                 } else
 181                         return -EIO;
 182         }
 183
 184         return num;
 185 }
 186
 187 static u32 go7007_functionality(struct i2c_adapter *adapter)
 188 {
 189         return I2C_FUNC_SMBUS_BYTE_DATA;
 190 }
 191
 192 static const struct i2c_algorithm go7007_algo = {
 193         .smbus_xfer     = go7007_smbus_xfer,
 194         .master_xfer    = go7007_i2c_master_xfer,
 195         .functionality  = go7007_functionality,
 196 };
 197
 198 static struct i2c_adapter go7007_adap_templ = {
 199         .owner                  = THIS_MODULE,
 200         .name                   = "WIS GO7007SB",
 201         .algo                   = &go7007_algo,
 202 };
 203
 204 int go7007_i2c_init(struct go7007 *go)
 205 {
 206         memcpy(&go->i2c_adapter, &go7007_adap_templ,
 207                         sizeof(go7007_adap_templ));
 208         go->i2c_adapter.dev.parent = go->dev;
 209         i2c_set_adapdata(&go->i2c_adapter, go);
 210         if (i2c_add_adapter(&go->i2c_adapter) < 0) {
 211                 dev_err(go->dev,
 212                         "go7007-i2c: error: i2c_add_adapter failed\n");
 213                 return -1;
 214         }
 215         return 0;
 216 }