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

   1 /*
   2  * Linux driver for digital TV devices equipped with B2C2 FlexcopII(b)/III
   3  * flexcop-i2c.c - flexcop internal 2Wire bus (I2C) and dvb i2c initialization
   4  * see flexcop.c for copyright information
   5  */
   6 #include "flexcop.h"
   7
   8 #define FC_MAX_I2C_RETRIES 100000
   9
  10 static int flexcop_i2c_operation(struct flexcop_device *fc,
  11                 flexcop_ibi_value *r100)
  12 {
  13         int i;
  14         flexcop_ibi_value r;
  15
  16         r100->tw_sm_c_100.working_start = 1;
  17         deb_i2c("r100 before: %08x\n",r100->raw);
  18
  19         fc->write_ibi_reg(fc, tw_sm_c_100, ibi_zero);
  20         fc->write_ibi_reg(fc, tw_sm_c_100, *r100); /* initiating i2c operation */
  21
  22         for (i = 0; i < FC_MAX_I2C_RETRIES; i++) {
  23                 r = fc->read_ibi_reg(fc, tw_sm_c_100);
  24
  25                 if (!r.tw_sm_c_100.no_base_addr_ack_error) {
  26                         if (r.tw_sm_c_100.st_done) {
  27                                 *r100 = r;
  28                                 deb_i2c("i2c success\n");
  29                                 return 0;
  30                         }
  31                 } else {
  32                         deb_i2c("suffering from an i2c ack_error\n");
  33                         return -EREMOTEIO;
  34                 }
  35         }
  36         deb_i2c("tried %d times i2c operation, "
  37                         "never finished or too many ack errors.\n", i);
  38         return -EREMOTEIO;
  39 }
  40
  41 static int flexcop_i2c_read4(struct flexcop_i2c_adapter *i2c,
  42                 flexcop_ibi_value r100, u8 *buf)
  43 {
  44         flexcop_ibi_value r104;
  45         int len = r100.tw_sm_c_100.total_bytes,
  46                 /* remember total_bytes is buflen-1 */
  47                 ret;
  48
  49         /* work-around to have CableStar2 and SkyStar2 rev 2.7 work
  50          * correctly:
  51          *
  52          * the ITD1000 is behind an i2c-gate which closes automatically
  53          * after an i2c-transaction the STV0297 needs 2 consecutive reads
  54          * one with no_base_addr = 0 and one with 1
  55          *
  56          * those two work-arounds are conflictin: we check for the card
  57          * type, it is set when probing the ITD1000 */
  58         if (i2c->fc->dev_type == FC_SKY_REV27)
  59                 r100.tw_sm_c_100.no_base_addr_ack_error = i2c->no_base_addr;
  60
  61         ret = flexcop_i2c_operation(i2c->fc, &r100);
  62         if (ret != 0) {
  63                 deb_i2c("Retrying operation\n");
  64                 r100.tw_sm_c_100.no_base_addr_ack_error = i2c->no_base_addr;
  65                 ret = flexcop_i2c_operation(i2c->fc, &r100);
  66         }
  67         if (ret != 0) {
  68                 deb_i2c("read failed. %d\n", ret);
  69                 return ret;
  70         }
  71
  72         buf[0] = r100.tw_sm_c_100.data1_reg;
  73
  74         if (len > 0) {
  75                 r104 = i2c->fc->read_ibi_reg(i2c->fc, tw_sm_c_104);
  76                 deb_i2c("read: r100: %08x, r104: %08x\n", r100.raw, r104.raw);
  77
  78                 /* there is at least one more byte, otherwise we wouldn't be here */
  79                 buf[1] = r104.tw_sm_c_104.data2_reg;
  80                 if (len > 1) buf[2] = r104.tw_sm_c_104.data3_reg;
  81                 if (len > 2) buf[3] = r104.tw_sm_c_104.data4_reg;
  82         }
  83         return 0;
  84 }
  85
  86 static int flexcop_i2c_write4(struct flexcop_device *fc,
  87                 flexcop_ibi_value r100, u8 *buf)
  88 {
  89         flexcop_ibi_value r104;
  90         int len = r100.tw_sm_c_100.total_bytes; /* remember total_bytes is buflen-1 */
  91         r104.raw = 0;
  92
  93         /* there is at least one byte, otherwise we wouldn't be here */
  94         r100.tw_sm_c_100.data1_reg = buf[0];
  95         r104.tw_sm_c_104.data2_reg = len > 0 ? buf[1] : 0;
  96         r104.tw_sm_c_104.data3_reg = len > 1 ? buf[2] : 0;
  97         r104.tw_sm_c_104.data4_reg = len > 2 ? buf[3] : 0;
  98
  99         deb_i2c("write: r100: %08x, r104: %08x\n", r100.raw, r104.raw);
 100
 101         /* write the additional i2c data before doing the actual i2c operation */
 102         fc->write_ibi_reg(fc, tw_sm_c_104, r104);
 103         return flexcop_i2c_operation(fc, &r100);
 104 }
 105
 106 int flexcop_i2c_request(struct flexcop_i2c_adapter *i2c,
 107                 flexcop_access_op_t op, u8 chipaddr, u8 addr, u8 *buf, u16 len)
 108 {
 109         int ret;
 110
 111 #ifdef DUMP_I2C_MESSAGES
 112         int i;
 113 #endif
 114
 115         u16 bytes_to_transfer;
 116         flexcop_ibi_value r100;
 117
 118         deb_i2c("op = %d\n",op);
 119         r100.raw = 0;
 120         r100.tw_sm_c_100.chipaddr = chipaddr;
 121         r100.tw_sm_c_100.twoWS_rw = op;
 122         r100.tw_sm_c_100.twoWS_port_reg = i2c->port;
 123
 124 #ifdef DUMP_I2C_MESSAGES
 125         printk(KERN_DEBUG "%d ", i2c->port);
 126         if (op == FC_READ)
 127                 printk("rd(");
 128         else
 129                 printk("wr(");
 130         printk("%02x): %02x ", chipaddr, addr);
 131 #endif
 132
 133         /* in that case addr is the only value ->
 134          * we write it twice as baseaddr and val0
 135          * BBTI is doing it like that for ISL6421 at least */
 136         if (i2c->no_base_addr && len == 0 && op == FC_WRITE) {
 137                 buf = &addr;
 138                 len = 1;
 139         }
 140
 141         while (len != 0) {
 142                 bytes_to_transfer = len > 4 ? 4 : len;
 143
 144                 r100.tw_sm_c_100.total_bytes = bytes_to_transfer - 1;
 145                 r100.tw_sm_c_100.baseaddr = addr;
 146
 147                 if (op == FC_READ)
 148                         ret = flexcop_i2c_read4(i2c, r100, buf);
 149                 else
 150                         ret = flexcop_i2c_write4(i2c->fc, r100, buf);
 151
 152 #ifdef DUMP_I2C_MESSAGES
 153                 for (i = 0; i < bytes_to_transfer; i++)
 154                         printk("%02x ", buf[i]);
 155 #endif
 156
 157                 if (ret < 0)
 158                         return ret;
 159
 160                 buf  += bytes_to_transfer;
 161                 addr += bytes_to_transfer;
 162                 len  -= bytes_to_transfer;
 163         }
 164
 165 #ifdef DUMP_I2C_MESSAGES
 166         printk("\n");
 167 #endif
 168
 169         return 0;
 170 }
 171 /* exported for PCI i2c */
 172 EXPORT_SYMBOL(flexcop_i2c_request);
 173
 174 /* master xfer callback for demodulator */
 175 static int flexcop_master_xfer(struct i2c_adapter *i2c_adap,
 176                 struct i2c_msg msgs[], int num)
 177 {
 178         struct flexcop_i2c_adapter *i2c = i2c_get_adapdata(i2c_adap);
 179         int i, ret = 0;
 180
 181         /* Some drivers use 1 byte or 0 byte reads as probes, which this
 182          * driver doesn't support.  These probes will always fail, so this
 183          * hack makes them always succeed.  If one knew how, it would of
 184          * course be better to actually do the read.  */
 185         if (num == 1 && msgs[0].flags == I2C_M_RD && msgs[0].len <= 1)
 186                 return 1;
 187
 188         if (mutex_lock_interruptible(&i2c->fc->i2c_mutex))
 189                 return -ERESTARTSYS;
 190
 191         for (i = 0; i < num; i++) {
 192                 /* reading */
 193                 if (i+1 < num && (msgs[i+1].flags == I2C_M_RD)) {
 194                         ret = i2c->fc->i2c_request(i2c, FC_READ, msgs[i].addr,
 195                                         msgs[i].buf[0], msgs[i+1].buf,
 196                                         msgs[i+1].len);
 197                         i++; /* skip the following message */
 198                 } else /* writing */
 199                         ret = i2c->fc->i2c_request(i2c, FC_WRITE, msgs[i].addr,
 200                                         msgs[i].buf[0], &msgs[i].buf[1],
 201                                         msgs[i].len - 1);
 202                 if (ret < 0) {
 203                         deb_i2c("i2c master_xfer failed");
 204                         break;
 205                 }
 206         }
 207
 208         mutex_unlock(&i2c->fc->i2c_mutex);
 209
 210         if (ret == 0)
 211                 ret = num;
 212         return ret;
 213 }
 214
 215 static u32 flexcop_i2c_func(struct i2c_adapter *adapter)
 216 {
 217         return I2C_FUNC_I2C;
 218 }
 219
 220 static struct i2c_algorithm flexcop_algo = {
 221         .master_xfer    = flexcop_master_xfer,
 222         .functionality  = flexcop_i2c_func,
 223 };
 224
 225 int flexcop_i2c_init(struct flexcop_device *fc)
 226 {
 227         int ret;
 228         mutex_init(&fc->i2c_mutex);
 229
 230         fc->fc_i2c_adap[0].fc = fc;
 231         fc->fc_i2c_adap[1].fc = fc;
 232         fc->fc_i2c_adap[2].fc = fc;
 233         fc->fc_i2c_adap[0].port = FC_I2C_PORT_DEMOD;
 234         fc->fc_i2c_adap[1].port = FC_I2C_PORT_EEPROM;
 235         fc->fc_i2c_adap[2].port = FC_I2C_PORT_TUNER;
 236
 237         strlcpy(fc->fc_i2c_adap[0].i2c_adap.name, "B2C2 FlexCop I2C to demod",
 238                         sizeof(fc->fc_i2c_adap[0].i2c_adap.name));
 239         strlcpy(fc->fc_i2c_adap[1].i2c_adap.name, "B2C2 FlexCop I2C to eeprom",
 240                         sizeof(fc->fc_i2c_adap[1].i2c_adap.name));
 241         strlcpy(fc->fc_i2c_adap[2].i2c_adap.name, "B2C2 FlexCop I2C to tuner",
 242                         sizeof(fc->fc_i2c_adap[2].i2c_adap.name));
 243
 244         i2c_set_adapdata(&fc->fc_i2c_adap[0].i2c_adap, &fc->fc_i2c_adap[0]);
 245         i2c_set_adapdata(&fc->fc_i2c_adap[1].i2c_adap, &fc->fc_i2c_adap[1]);
 246         i2c_set_adapdata(&fc->fc_i2c_adap[2].i2c_adap, &fc->fc_i2c_adap[2]);
 247
 248         fc->fc_i2c_adap[0].i2c_adap.algo =
 249                 fc->fc_i2c_adap[1].i2c_adap.algo =
 250                 fc->fc_i2c_adap[2].i2c_adap.algo = &flexcop_algo;
 251         fc->fc_i2c_adap[0].i2c_adap.algo_data =
 252                 fc->fc_i2c_adap[1].i2c_adap.algo_data =
 253                 fc->fc_i2c_adap[2].i2c_adap.algo_data = NULL;
 254         fc->fc_i2c_adap[0].i2c_adap.dev.parent =
 255                 fc->fc_i2c_adap[1].i2c_adap.dev.parent =
 256                 fc->fc_i2c_adap[2].i2c_adap.dev.parent = fc->dev;
 257
 258         ret = i2c_add_adapter(&fc->fc_i2c_adap[0].i2c_adap);
 259         if (ret < 0)
 260                 return ret;
 261
 262         ret = i2c_add_adapter(&fc->fc_i2c_adap[1].i2c_adap);
 263         if (ret < 0)
 264                 goto adap_1_failed;
 265
 266         ret = i2c_add_adapter(&fc->fc_i2c_adap[2].i2c_adap);
 267         if (ret < 0)
 268                 goto adap_2_failed;
 269
 270         fc->init_state |= FC_STATE_I2C_INIT;
 271         return 0;
 272
 273 adap_2_failed:
 274         i2c_del_adapter(&fc->fc_i2c_adap[1].i2c_adap);
 275 adap_1_failed:
 276         i2c_del_adapter(&fc->fc_i2c_adap[0].i2c_adap);
 277         return ret;
 278 }
 279
 280 void flexcop_i2c_exit(struct flexcop_device *fc)
 281 {
 282         if (fc->init_state & FC_STATE_I2C_INIT) {
 283                 i2c_del_adapter(&fc->fc_i2c_adap[2].i2c_adap);
 284                 i2c_del_adapter(&fc->fc_i2c_adap[1].i2c_adap);
 285                 i2c_del_adapter(&fc->fc_i2c_adap[0].i2c_adap);
 286         }
 287         fc->init_state &= ~FC_STATE_I2C_INIT;
 288 }