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