drivers/media/dvb/b2c2/flexcop-i2c.c

   1 /*
   2  * This file is part of linux driver the digital TV devices equipped with B2C2 FlexcopII(b)/III
   3  *
   4  * flexcop-i2c.c - flexcop internal 2Wire bus (I2C) and dvb i2c initialization
   5  *
   6  * see flexcop.c for copyright information.
   7  */
   8 #include "flexcop.h"
   9
  10 #define FC_MAX_I2C_RETRIES 100000
  11
  12 /* #define DUMP_I2C_MESSAGES */
  13
  14 static int flexcop_i2c_operation(struct flexcop_device *fc, flexcop_ibi_value *r100)
  15 {
  16         int i;
  17         flexcop_ibi_value r;
  18
  19         r100->tw_sm_c_100.working_start = 1;
  20         deb_i2c("r100 before: %08x\n",r100->raw);
  21
  22         fc->write_ibi_reg(fc, tw_sm_c_100, ibi_zero);
  23         fc->write_ibi_reg(fc, tw_sm_c_100, *r100); /* initiating i2c operation */
  24
  25         for (i = 0; i < FC_MAX_I2C_RETRIES; i++) {
  26                 r = fc->read_ibi_reg(fc, tw_sm_c_100);
  27
  28                 if (!r.tw_sm_c_100.no_base_addr_ack_error) {
  29                         if (r.tw_sm_c_100.st_done) {  /* && !r.tw_sm_c_100.working_start */
  30                                 *r100 = r;
  31                                 deb_i2c("i2c success\n");
  32                                 return 0;
  33                         }
  34                 } else {
  35                         deb_i2c("suffering from an i2c ack_error\n");
  36                         return -EREMOTEIO;
  37                 }
  38         }
  39         deb_i2c("tried %d times i2c operation, never finished or too many ack errors.\n",i);
  40         return -EREMOTEIO;
  41 }
  42
  43 static int flexcop_i2c_read4(struct flexcop_i2c_adapter *i2c,
  44         flexcop_ibi_value r100, u8 *buf)
  45 {
  46         flexcop_ibi_value r104;
  47         int len = r100.tw_sm_c_100.total_bytes, /* remember total_bytes is buflen-1 */
  48                 ret;
  49
  50         r100.tw_sm_c_100.no_base_addr_ack_error = i2c->no_base_addr;
  51         ret = flexcop_i2c_operation(i2c->fc, &r100);
  52         if (ret != 0) {
  53                 deb_i2c("read failed. %d\n", ret);
  54                 return ret;
  55         }
  56
  57         buf[0] = r100.tw_sm_c_100.data1_reg;
  58
  59         if (len > 0) {
  60                 r104 = i2c->fc->read_ibi_reg(i2c->fc, tw_sm_c_104);
  61                 deb_i2c("read: r100: %08x, r104: %08x\n", r100.raw, r104.raw);
  62
  63                 /* there is at least one more byte, otherwise we wouldn't be here */
  64                 buf[1] = r104.tw_sm_c_104.data2_reg;
  65                 if (len > 1) buf[2] = r104.tw_sm_c_104.data3_reg;
  66                 if (len > 2) buf[3] = r104.tw_sm_c_104.data4_reg;
  67         }
  68
  69         return 0;
  70 }
  71
  72 static int flexcop_i2c_write4(struct flexcop_device *fc, flexcop_ibi_value r100, u8 *buf)
  73 {
  74         flexcop_ibi_value r104;
  75         int len = r100.tw_sm_c_100.total_bytes; /* remember total_bytes is buflen-1 */
  76         r104.raw = 0;
  77
  78         /* there is at least one byte, otherwise we wouldn't be here */
  79         r100.tw_sm_c_100.data1_reg = buf[0];
  80
  81         r104.tw_sm_c_104.data2_reg = len > 0 ? buf[1] : 0;
  82         r104.tw_sm_c_104.data3_reg = len > 1 ? buf[2] : 0;
  83         r104.tw_sm_c_104.data4_reg = len > 2 ? buf[3] : 0;
  84
  85         deb_i2c("write: r100: %08x, r104: %08x\n", r100.raw, r104.raw);
  86
  87         /* write the additional i2c data before doing the actual i2c operation */
  88         fc->write_ibi_reg(fc, tw_sm_c_104, r104);
  89         return flexcop_i2c_operation(fc, &r100);
  90 }
  91
  92 int flexcop_i2c_request(struct flexcop_i2c_adapter *i2c,
  93         flexcop_access_op_t op, u8 chipaddr, u8 addr, u8 *buf, u16 len)
  94 {
  95         int ret;
  96
  97 #ifdef DUMP_I2C_MESSAGES
  98         int i;
  99 #endif
 100
 101         u16 bytes_to_transfer;
 102         flexcop_ibi_value r100;
 103
 104         deb_i2c("op = %d\n",op);
 105         r100.raw = 0;
 106         r100.tw_sm_c_100.chipaddr = chipaddr;
 107         r100.tw_sm_c_100.twoWS_rw = op;
 108         r100.tw_sm_c_100.twoWS_port_reg = i2c->port;
 109
 110 #ifdef DUMP_I2C_MESSAGES
 111         printk(KERN_DEBUG "%d ", i2c->port);
 112         if (op == FC_READ)
 113                 printk("rd(");
 114         else
 115                 printk("wr(");
 116
 117         printk("%02x): %02x ", chipaddr, addr);
 118 #endif
 119
 120         /* in that case addr is the only value ->
 121          * we write it twice as baseaddr and val0
 122          * BBTI is doing it like that for ISL6421 at least */
 123         if (i2c->no_base_addr && len == 0 && op == FC_WRITE) {
 124                 buf = &addr;
 125                 len = 1;
 126         }
 127
 128         while (len != 0) {
 129                 bytes_to_transfer = len > 4 ? 4 : len;
 130
 131                 r100.tw_sm_c_100.total_bytes = bytes_to_transfer - 1;
 132                 r100.tw_sm_c_100.baseaddr = addr;
 133
 134                 if (op == FC_READ)
 135                         ret = flexcop_i2c_read4(i2c, r100, buf);
 136                 else
 137                         ret = flexcop_i2c_write4(i2c->fc, r100, buf);
 138
 139 #ifdef DUMP_I2C_MESSAGES
 140                 for (i = 0; i < bytes_to_transfer; i++)
 141                         printk("%02x ", buf[i]);
 142 #endif
 143
 144                 if (ret < 0)
 145                         return ret;
 146
 147                 buf  += bytes_to_transfer;
 148                 addr += bytes_to_transfer;
 149                 len  -= bytes_to_transfer;
 150         }
 151
 152 #ifdef DUMP_I2C_MESSAGES
 153         printk("\n");
 154 #endif
 155
 156         return 0;
 157 }
 158 /* exported for PCI i2c */
 159 EXPORT_SYMBOL(flexcop_i2c_request);
 160
 161 /* master xfer callback for demodulator */
 162 static int flexcop_master_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg msgs[], int num)
 163 {
 164         struct flexcop_i2c_adapter *i2c = i2c_get_adapdata(i2c_adap);
 165         int i, ret = 0;
 166
 167         /* Some drivers use 1 byte or 0 byte reads as probes, which this
 168          * driver doesn't support.  These probes will always fail, so this
 169          * hack makes them always succeed.  If one knew how, it would of
 170          * course be better to actually do the read.  */
 171         if (num == 1 && msgs[0].flags == I2C_M_RD && msgs[0].len <= 1)
 172                 return 1;
 173
 174         if (mutex_lock_interruptible(&i2c->fc->i2c_mutex))
 175                 return -ERESTARTSYS;
 176
 177         for (i = 0; i < num; i++) {
 178                 /* reading */
 179                 if (i+1 < num && (msgs[i+1].flags == I2C_M_RD)) {
 180                         ret = i2c->fc->i2c_request(i2c, FC_READ, msgs[i].addr,
 181                                 msgs[i].buf[0], msgs[i+1].buf, msgs[i+1].len);
 182                         i++; /* skip the following message */
 183                 } else /* writing */
 184                         ret = i2c->fc->i2c_request(i2c, FC_WRITE, msgs[i].addr,
 185                                 msgs[i].buf[0], &msgs[i].buf[1],
 186                                 msgs[i].len - 1);
 187                 if (ret < 0) {
 188                         err("i2c master_xfer failed");
 189                         break;
 190                 }
 191         }
 192
 193         mutex_unlock(&i2c->fc->i2c_mutex);
 194
 195         if (ret == 0)
 196                 ret = num;
 197         return ret;
 198 }
 199
 200 static u32 flexcop_i2c_func(struct i2c_adapter *adapter)
 201 {
 202         return I2C_FUNC_I2C;
 203 }
 204
 205 static struct i2c_algorithm flexcop_algo = {
 206         .master_xfer    = flexcop_master_xfer,
 207         .functionality  = flexcop_i2c_func,
 208 };
 209
 210 int flexcop_i2c_init(struct flexcop_device *fc)
 211 {
 212         int ret;
 213
 214         mutex_init(&fc->i2c_mutex);
 215
 216         fc->fc_i2c_adap[0].fc = fc;
 217         fc->fc_i2c_adap[1].fc = fc;
 218         fc->fc_i2c_adap[2].fc = fc;
 219
 220         fc->fc_i2c_adap[0].port = FC_I2C_PORT_DEMOD;
 221         fc->fc_i2c_adap[1].port = FC_I2C_PORT_EEPROM;
 222         fc->fc_i2c_adap[2].port = FC_I2C_PORT_TUNER;
 223
 224         strncpy(fc->fc_i2c_adap[0].i2c_adap.name,
 225                 "B2C2 FlexCop I2C to demod", I2C_NAME_SIZE);
 226         strncpy(fc->fc_i2c_adap[1].i2c_adap.name,
 227                 "B2C2 FlexCop I2C to eeprom", I2C_NAME_SIZE);
 228         strncpy(fc->fc_i2c_adap[2].i2c_adap.name,
 229                 "B2C2 FlexCop I2C to tuner", I2C_NAME_SIZE);
 230
 231         i2c_set_adapdata(&fc->fc_i2c_adap[0].i2c_adap, &fc->fc_i2c_adap[0]);
 232         i2c_set_adapdata(&fc->fc_i2c_adap[1].i2c_adap, &fc->fc_i2c_adap[1]);
 233         i2c_set_adapdata(&fc->fc_i2c_adap[2].i2c_adap, &fc->fc_i2c_adap[2]);
 234
 235         fc->fc_i2c_adap[0].i2c_adap.class =
 236                 fc->fc_i2c_adap[1].i2c_adap.class =
 237                 fc->fc_i2c_adap[2].i2c_adap.class = I2C_CLASS_TV_DIGITAL;
 238         fc->fc_i2c_adap[0].i2c_adap.algo =
 239                 fc->fc_i2c_adap[1].i2c_adap.algo =
 240                 fc->fc_i2c_adap[2].i2c_adap.algo = &flexcop_algo;
 241         fc->fc_i2c_adap[0].i2c_adap.algo_data =
 242                 fc->fc_i2c_adap[1].i2c_adap.algo_data =
 243                 fc->fc_i2c_adap[2].i2c_adap.algo_data = NULL;
 244         fc->fc_i2c_adap[0].i2c_adap.dev.parent =
 245                 fc->fc_i2c_adap[1].i2c_adap.dev.parent =
 246                 fc->fc_i2c_adap[2].i2c_adap.dev.parent = fc->dev;
 247
 248         ret = i2c_add_adapter(&fc->fc_i2c_adap[0].i2c_adap);
 249         if (ret < 0)
 250                 return ret;
 251
 252         ret = i2c_add_adapter(&fc->fc_i2c_adap[1].i2c_adap);
 253         if (ret < 0)
 254                 goto adap_1_failed;
 255
 256         ret = i2c_add_adapter(&fc->fc_i2c_adap[2].i2c_adap);
 257         if (ret < 0)
 258                 goto adap_2_failed;
 259
 260         fc->init_state |= FC_STATE_I2C_INIT;
 261         return 0;
 262
 263 adap_2_failed:
 264         i2c_del_adapter(&fc->fc_i2c_adap[1].i2c_adap);
 265 adap_1_failed:
 266         i2c_del_adapter(&fc->fc_i2c_adap[0].i2c_adap);
 267
 268         return ret;
 269 }
 270
 271 void flexcop_i2c_exit(struct flexcop_device *fc)
 272 {
 273         if (fc->init_state & FC_STATE_I2C_INIT) {
 274                 i2c_del_adapter(&fc->fc_i2c_adap[2].i2c_adap);
 275                 i2c_del_adapter(&fc->fc_i2c_adap[1].i2c_adap);
 276                 i2c_del_adapter(&fc->fc_i2c_adap[0].i2c_adap);
 277         }
 278
 279         fc->init_state &= ~FC_STATE_I2C_INIT;
 280 }