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         ret = flexcop_i2c_operation(i2c->fc, &r100);
  51         if (ret != 0) {
  52                 deb_i2c("Retrying operation\n");
  53                 r100.tw_sm_c_100.no_base_addr_ack_error = i2c->no_base_addr;
  54                 ret = flexcop_i2c_operation(i2c->fc, &r100);
  55         }
  56         if (ret != 0) {
  57                 deb_i2c("read failed. %d\n", ret);
  58                 return ret;
  59         }
  60
  61         buf[0] = r100.tw_sm_c_100.data1_reg;
  62
  63         if (len > 0) {
  64                 r104 = i2c->fc->read_ibi_reg(i2c->fc, tw_sm_c_104);
  65                 deb_i2c("read: r100: %08x, r104: %08x\n", r100.raw, r104.raw);
  66
  67                 /* there is at least one more byte, otherwise we wouldn't be here */
  68                 buf[1] = r104.tw_sm_c_104.data2_reg;
  69                 if (len > 1) buf[2] = r104.tw_sm_c_104.data3_reg;
  70                 if (len > 2) buf[3] = r104.tw_sm_c_104.data4_reg;
  71         }
  72
  73         return 0;
  74 }
  75
  76 static int flexcop_i2c_write4(struct flexcop_device *fc, flexcop_ibi_value r100, u8 *buf)
  77 {
  78         flexcop_ibi_value r104;
  79         int len = r100.tw_sm_c_100.total_bytes; /* remember total_bytes is buflen-1 */
  80         r104.raw = 0;
  81
  82         /* there is at least one byte, otherwise we wouldn't be here */
  83         r100.tw_sm_c_100.data1_reg = buf[0];
  84
  85         r104.tw_sm_c_104.data2_reg = len > 0 ? buf[1] : 0;
  86         r104.tw_sm_c_104.data3_reg = len > 1 ? buf[2] : 0;
  87         r104.tw_sm_c_104.data4_reg = len > 2 ? buf[3] : 0;
  88
  89         deb_i2c("write: r100: %08x, r104: %08x\n", r100.raw, r104.raw);
  90
  91         /* write the additional i2c data before doing the actual i2c operation */
  92         fc->write_ibi_reg(fc, tw_sm_c_104, r104);
  93         return flexcop_i2c_operation(fc, &r100);
  94 }
  95
  96 int flexcop_i2c_request(struct flexcop_i2c_adapter *i2c,
  97         flexcop_access_op_t op, u8 chipaddr, u8 addr, u8 *buf, u16 len)
  98 {
  99         int ret;
 100
 101 #ifdef DUMP_I2C_MESSAGES
 102         int i;
 103 #endif
 104
 105         u16 bytes_to_transfer;
 106         flexcop_ibi_value r100;
 107
 108         deb_i2c("op = %d\n",op);
 109         r100.raw = 0;
 110         r100.tw_sm_c_100.chipaddr = chipaddr;
 111         r100.tw_sm_c_100.twoWS_rw = op;
 112         r100.tw_sm_c_100.twoWS_port_reg = i2c->port;
 113
 114 #ifdef DUMP_I2C_MESSAGES
 115         printk(KERN_DEBUG "%d ", i2c->port);
 116         if (op == FC_READ)
 117                 printk("rd(");
 118         else
 119                 printk("wr(");
 120
 121         printk("%02x): %02x ", chipaddr, addr);
 122 #endif
 123
 124         /* in that case addr is the only value ->
 125          * we write it twice as baseaddr and val0
 126          * BBTI is doing it like that for ISL6421 at least */
 127         if (i2c->no_base_addr && len == 0 && op == FC_WRITE) {
 128                 buf = &addr;
 129                 len = 1;
 130         }
 131
 132         while (len != 0) {
 133                 bytes_to_transfer = len > 4 ? 4 : len;
 134
 135                 r100.tw_sm_c_100.total_bytes = bytes_to_transfer - 1;
 136                 r100.tw_sm_c_100.baseaddr = addr;
 137
 138                 if (op == FC_READ)
 139                         ret = flexcop_i2c_read4(i2c, r100, buf);
 140                 else
 141                         ret = flexcop_i2c_write4(i2c->fc, r100, buf);
 142
 143 #ifdef DUMP_I2C_MESSAGES
 144                 for (i = 0; i < bytes_to_transfer; i++)
 145                         printk("%02x ", buf[i]);
 146 #endif
 147
 148                 if (ret < 0)
 149                         return ret;
 150
 151                 buf  += bytes_to_transfer;
 152                 addr += bytes_to_transfer;
 153                 len  -= bytes_to_transfer;
 154         }
 155
 156 #ifdef DUMP_I2C_MESSAGES
 157         printk("\n");
 158 #endif
 159
 160         return 0;
 161 }
 162 /* exported for PCI i2c */
 163 EXPORT_SYMBOL(flexcop_i2c_request);
 164
 165 /* master xfer callback for demodulator */
 166 static int flexcop_master_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg msgs[], int num)
 167 {
 168         struct flexcop_i2c_adapter *i2c = i2c_get_adapdata(i2c_adap);
 169         int i, ret = 0;
 170
 171         /* Some drivers use 1 byte or 0 byte reads as probes, which this
 172          * driver doesn't support.  These probes will always fail, so this
 173          * hack makes them always succeed.  If one knew how, it would of
 174          * course be better to actually do the read.  */
 175         if (num == 1 && msgs[0].flags == I2C_M_RD && msgs[0].len <= 1)
 176                 return 1;
 177
 178         if (mutex_lock_interruptible(&i2c->fc->i2c_mutex))
 179                 return -ERESTARTSYS;
 180
 181         for (i = 0; i < num; i++) {
 182                 /* reading */
 183                 if (i+1 < num && (msgs[i+1].flags == I2C_M_RD)) {
 184                         ret = i2c->fc->i2c_request(i2c, FC_READ, msgs[i].addr,
 185                                 msgs[i].buf[0], msgs[i+1].buf, msgs[i+1].len);
 186                         i++; /* skip the following message */
 187                 } else /* writing */
 188                         ret = i2c->fc->i2c_request(i2c, FC_WRITE, msgs[i].addr,
 189                                 msgs[i].buf[0], &msgs[i].buf[1],
 190                                 msgs[i].len - 1);
 191                 if (ret < 0) {
 192                         err("i2c master_xfer failed");
 193                         break;
 194                 }
 195         }
 196
 197         mutex_unlock(&i2c->fc->i2c_mutex);
 198
 199         if (ret == 0)
 200                 ret = num;
 201         return ret;
 202 }
 203
 204 static u32 flexcop_i2c_func(struct i2c_adapter *adapter)
 205 {
 206         return I2C_FUNC_I2C;
 207 }
 208
 209 static struct i2c_algorithm flexcop_algo = {
 210         .master_xfer    = flexcop_master_xfer,
 211         .functionality  = flexcop_i2c_func,
 212 };
 213
 214 int flexcop_i2c_init(struct flexcop_device *fc)
 215 {
 216         int ret;
 217
 218         mutex_init(&fc->i2c_mutex);
 219
 220         fc->fc_i2c_adap[0].fc = fc;
 221         fc->fc_i2c_adap[1].fc = fc;
 222         fc->fc_i2c_adap[2].fc = fc;
 223
 224         fc->fc_i2c_adap[0].port = FC_I2C_PORT_DEMOD;
 225         fc->fc_i2c_adap[1].port = FC_I2C_PORT_EEPROM;
 226         fc->fc_i2c_adap[2].port = FC_I2C_PORT_TUNER;
 227
 228         strlcpy(fc->fc_i2c_adap[0].i2c_adap.name, "B2C2 FlexCop I2C to demod",
 229                 sizeof(fc->fc_i2c_adap[0].i2c_adap.name));
 230         strlcpy(fc->fc_i2c_adap[1].i2c_adap.name, "B2C2 FlexCop I2C to eeprom",
 231                 sizeof(fc->fc_i2c_adap[1].i2c_adap.name));
 232         strlcpy(fc->fc_i2c_adap[2].i2c_adap.name, "B2C2 FlexCop I2C to tuner",
 233                 sizeof(fc->fc_i2c_adap[2].i2c_adap.name));
 234
 235         i2c_set_adapdata(&fc->fc_i2c_adap[0].i2c_adap, &fc->fc_i2c_adap[0]);
 236         i2c_set_adapdata(&fc->fc_i2c_adap[1].i2c_adap, &fc->fc_i2c_adap[1]);
 237         i2c_set_adapdata(&fc->fc_i2c_adap[2].i2c_adap, &fc->fc_i2c_adap[2]);
 238
 239         fc->fc_i2c_adap[0].i2c_adap.class =
 240                 fc->fc_i2c_adap[1].i2c_adap.class =
 241                 fc->fc_i2c_adap[2].i2c_adap.class = I2C_CLASS_TV_DIGITAL;
 242         fc->fc_i2c_adap[0].i2c_adap.algo =
 243                 fc->fc_i2c_adap[1].i2c_adap.algo =
 244                 fc->fc_i2c_adap[2].i2c_adap.algo = &flexcop_algo;
 245         fc->fc_i2c_adap[0].i2c_adap.algo_data =
 246                 fc->fc_i2c_adap[1].i2c_adap.algo_data =
 247                 fc->fc_i2c_adap[2].i2c_adap.algo_data = NULL;
 248         fc->fc_i2c_adap[0].i2c_adap.dev.parent =
 249                 fc->fc_i2c_adap[1].i2c_adap.dev.parent =
 250                 fc->fc_i2c_adap[2].i2c_adap.dev.parent = fc->dev;
 251
 252         ret = i2c_add_adapter(&fc->fc_i2c_adap[0].i2c_adap);
 253         if (ret < 0)
 254                 return ret;
 255
 256         ret = i2c_add_adapter(&fc->fc_i2c_adap[1].i2c_adap);
 257         if (ret < 0)
 258                 goto adap_1_failed;
 259
 260         ret = i2c_add_adapter(&fc->fc_i2c_adap[2].i2c_adap);
 261         if (ret < 0)
 262                 goto adap_2_failed;
 263
 264         fc->init_state |= FC_STATE_I2C_INIT;
 265         return 0;
 266
 267 adap_2_failed:
 268         i2c_del_adapter(&fc->fc_i2c_adap[1].i2c_adap);
 269 adap_1_failed:
 270         i2c_del_adapter(&fc->fc_i2c_adap[0].i2c_adap);
 271
 272         return ret;
 273 }
 274
 275 void flexcop_i2c_exit(struct flexcop_device *fc)
 276 {
 277         if (fc->init_state & FC_STATE_I2C_INIT) {
 278                 i2c_del_adapter(&fc->fc_i2c_adap[2].i2c_adap);
 279                 i2c_del_adapter(&fc->fc_i2c_adap[1].i2c_adap);
 280                 i2c_del_adapter(&fc->fc_i2c_adap[0].i2c_adap);
 281         }
 282
 283         fc->init_state &= ~FC_STATE_I2C_INIT;
 284 }