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

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Linux driver for digital TV devices equipped with B2C2 FlexcopII(b)/III
   4  * flexcop-i2c.c - flexcop internal 2Wire bus (I2C) and dvb i2c initialization
   5  * see flexcop.c for copyright information
   6  */
   7 #include "flexcop.h"
   8
   9 #define FC_MAX_I2C_RETRIES 100000
  10
  11 static int flexcop_i2c_operation(struct flexcop_device *fc,
  12                 flexcop_ibi_value *r100)
  13 {
  14         int i;
  15         flexcop_ibi_value r;
  16
  17         r100->tw_sm_c_100.working_start = 1;
  18         deb_i2c("r100 before: %08x\n",r100->raw);
  19
  20         fc->write_ibi_reg(fc, tw_sm_c_100, ibi_zero);
  21         fc->write_ibi_reg(fc, tw_sm_c_100, *r100); /* initiating i2c operation */
  22
  23         for (i = 0; i < FC_MAX_I2C_RETRIES; i++) {
  24                 r = fc->read_ibi_reg(fc, tw_sm_c_100);
  25
  26                 if (!r.tw_sm_c_100.no_base_addr_ack_error) {
  27                         if (r.tw_sm_c_100.st_done) {
  28                                 *r100 = r;
  29                                 deb_i2c("i2c success\n");
  30                                 return 0;
  31                         }
  32                 } else {
  33                         deb_i2c("suffering from an i2c ack_error\n");
  34                         return -EREMOTEIO;
  35                 }
  36         }
  37         deb_i2c("tried %d times i2c operation, never finished or too many ack errors.\n",
  38                 i);
  39         return -EREMOTEIO;
  40 }
  41
  42 static int flexcop_i2c_read4(struct flexcop_i2c_adapter *i2c,
  43                 flexcop_ibi_value r100, u8 *buf)
  44 {
  45         flexcop_ibi_value r104;
  46         int len = r100.tw_sm_c_100.total_bytes,
  47                 /* remember total_bytes is buflen-1 */
  48                 ret;
  49
  50         /* work-around to have CableStar2 and SkyStar2 rev 2.7 work
  51          * correctly:
  52          *
  53          * the ITD1000 is behind an i2c-gate which closes automatically
  54          * after an i2c-transaction the STV0297 needs 2 consecutive reads
  55          * one with no_base_addr = 0 and one with 1
  56          *
  57          * those two work-arounds are conflictin: we check for the card
  58          * type, it is set when probing the ITD1000 */
  59         if (i2c->fc->dev_type == FC_SKY_REV27)
  60                 r100.tw_sm_c_100.no_base_addr_ack_error = i2c->no_base_addr;
  61
  62         ret = flexcop_i2c_operation(i2c->fc, &r100);
  63         if (ret != 0) {
  64                 deb_i2c("Retrying operation\n");
  65                 r100.tw_sm_c_100.no_base_addr_ack_error = i2c->no_base_addr;
  66                 ret = flexcop_i2c_operation(i2c->fc, &r100);
  67         }
  68         if (ret != 0) {
  69                 deb_i2c("read failed. %d\n", ret);
  70                 return ret;
  71         }
  72
  73         buf[0] = r100.tw_sm_c_100.data1_reg;
  74
  75         if (len > 0) {
  76                 r104 = i2c->fc->read_ibi_reg(i2c->fc, tw_sm_c_104);
  77                 deb_i2c("read: r100: %08x, r104: %08x\n", r100.raw, r104.raw);
  78
  79                 /* there is at least one more byte, otherwise we wouldn't be here */
  80                 buf[1] = r104.tw_sm_c_104.data2_reg;
  81                 if (len > 1) buf[2] = r104.tw_sm_c_104.data3_reg;
  82                 if (len > 2) buf[3] = r104.tw_sm_c_104.data4_reg;
  83         }
  84         return 0;
  85 }
  86
  87 static int flexcop_i2c_write4(struct flexcop_device *fc,
  88                 flexcop_ibi_value r100, u8 *buf)
  89 {
  90         flexcop_ibi_value r104;
  91         int len = r100.tw_sm_c_100.total_bytes; /* remember total_bytes is buflen-1 */
  92         r104.raw = 0;
  93
  94         /* there is at least one byte, otherwise we wouldn't be here */
  95         r100.tw_sm_c_100.data1_reg = buf[0];
  96         r104.tw_sm_c_104.data2_reg = len > 0 ? buf[1] : 0;
  97         r104.tw_sm_c_104.data3_reg = len > 1 ? buf[2] : 0;
  98         r104.tw_sm_c_104.data4_reg = len > 2 ? buf[3] : 0;
  99
 100         deb_i2c("write: r100: %08x, r104: %08x\n", r100.raw, r104.raw);
 101
 102         /* write the additional i2c data before doing the actual i2c operation */
 103         fc->write_ibi_reg(fc, tw_sm_c_104, r104);
 104         return flexcop_i2c_operation(fc, &r100);
 105 }
 106
 107 int flexcop_i2c_request(struct flexcop_i2c_adapter *i2c,
 108                 flexcop_access_op_t op, u8 chipaddr, u8 addr, u8 *buf, u16 len)
 109 {
 110         int ret;
 111
 112 #ifdef DUMP_I2C_MESSAGES
 113         int i;
 114 #endif
 115
 116         u16 bytes_to_transfer;
 117         flexcop_ibi_value r100;
 118
 119         deb_i2c("op = %d\n",op);
 120         r100.raw = 0;
 121         r100.tw_sm_c_100.chipaddr = chipaddr;
 122         r100.tw_sm_c_100.twoWS_rw = op;
 123         r100.tw_sm_c_100.twoWS_port_reg = i2c->port;
 124
 125 #ifdef DUMP_I2C_MESSAGES
 126         printk(KERN_DEBUG "%d ", i2c->port);
 127         if (op == FC_READ)
 128                 printk(KERN_CONT "rd(");
 129         else
 130                 printk(KERN_CONT "wr(");
 131         printk(KERN_CONT "%02x): %02x ", chipaddr, addr);
 132 #endif
 133
 134         /* in that case addr is the only value ->
 135          * we write it twice as baseaddr and val0
 136          * BBTI is doing it like that for ISL6421 at least */
 137         if (i2c->no_base_addr && len == 0 && op == FC_WRITE) {
 138                 buf = &addr;
 139                 len = 1;
 140         }
 141
 142         while (len != 0) {
 143                 bytes_to_transfer = len > 4 ? 4 : len;
 144
 145                 r100.tw_sm_c_100.total_bytes = bytes_to_transfer - 1;
 146                 r100.tw_sm_c_100.baseaddr = addr;
 147
 148                 if (op == FC_READ)
 149                         ret = flexcop_i2c_read4(i2c, r100, buf);
 150                 else
 151                         ret = flexcop_i2c_write4(i2c->fc, r100, buf);
 152
 153 #ifdef DUMP_I2C_MESSAGES
 154                 for (i = 0; i < bytes_to_transfer; i++)
 155                         printk(KERN_CONT "%02x ", buf[i]);
 156 #endif
 157
 158                 if (ret < 0)
 159                         return ret;
 160
 161                 buf  += bytes_to_transfer;
 162                 addr += bytes_to_transfer;
 163                 len  -= bytes_to_transfer;
 164         }
 165
 166 #ifdef DUMP_I2C_MESSAGES
 167         printk(KERN_CONT "\n");
 168 #endif
 169
 170         return 0;
 171 }
 172 /* exported for PCI i2c */
 173 EXPORT_SYMBOL(flexcop_i2c_request);
 174
 175 /* master xfer callback for demodulator */
 176 static int flexcop_master_xfer(struct i2c_adapter *i2c_adap,
 177                 struct i2c_msg msgs[], int num)
 178 {
 179         struct flexcop_i2c_adapter *i2c = i2c_get_adapdata(i2c_adap);
 180         int i, ret = 0;
 181
 182         /* Some drivers use 1 byte or 0 byte reads as probes, which this
 183          * driver doesn't support.  These probes will always fail, so this
 184          * hack makes them always succeed.  If one knew how, it would of
 185          * course be better to actually do the read.  */
 186         if (num == 1 && msgs[0].flags == I2C_M_RD && msgs[0].len <= 1)
 187                 return 1;
 188
 189         if (mutex_lock_interruptible(&i2c->fc->i2c_mutex))
 190                 return -ERESTARTSYS;
 191
 192         for (i = 0; i < num; i++) {
 193                 /* reading */
 194                 if (i+1 < num && (msgs[i+1].flags == I2C_M_RD)) {
 195                         ret = i2c->fc->i2c_request(i2c, FC_READ, msgs[i].addr,
 196                                         msgs[i].buf[0], msgs[i+1].buf,
 197                                         msgs[i+1].len);
 198                         i++; /* skip the following message */
 199                 } else /* writing */
 200                         ret = i2c->fc->i2c_request(i2c, FC_WRITE, msgs[i].addr,
 201                                         msgs[i].buf[0], &msgs[i].buf[1],
 202                                         msgs[i].len - 1);
 203                 if (ret < 0) {
 204                         deb_i2c("i2c master_xfer failed");
 205                         break;
 206                 }
 207         }
 208
 209         mutex_unlock(&i2c->fc->i2c_mutex);
 210
 211         if (ret == 0)
 212                 ret = num;
 213         return ret;
 214 }
 215
 216 static u32 flexcop_i2c_func(struct i2c_adapter *adapter)
 217 {
 218         return I2C_FUNC_I2C;
 219 }
 220
 221 static struct i2c_algorithm flexcop_algo = {
 222         .master_xfer    = flexcop_master_xfer,
 223         .functionality  = flexcop_i2c_func,
 224 };
 225
 226 int flexcop_i2c_init(struct flexcop_device *fc)
 227 {
 228         int ret;
 229         mutex_init(&fc->i2c_mutex);
 230
 231         fc->fc_i2c_adap[0].fc = fc;
 232         fc->fc_i2c_adap[1].fc = fc;
 233         fc->fc_i2c_adap[2].fc = fc;
 234         fc->fc_i2c_adap[0].port = FC_I2C_PORT_DEMOD;
 235         fc->fc_i2c_adap[1].port = FC_I2C_PORT_EEPROM;
 236         fc->fc_i2c_adap[2].port = FC_I2C_PORT_TUNER;
 237
 238         strlcpy(fc->fc_i2c_adap[0].i2c_adap.name, "B2C2 FlexCop I2C to demod",
 239                         sizeof(fc->fc_i2c_adap[0].i2c_adap.name));
 240         strlcpy(fc->fc_i2c_adap[1].i2c_adap.name, "B2C2 FlexCop I2C to eeprom",
 241                         sizeof(fc->fc_i2c_adap[1].i2c_adap.name));
 242         strlcpy(fc->fc_i2c_adap[2].i2c_adap.name, "B2C2 FlexCop I2C to tuner",
 243                         sizeof(fc->fc_i2c_adap[2].i2c_adap.name));
 244
 245         i2c_set_adapdata(&fc->fc_i2c_adap[0].i2c_adap, &fc->fc_i2c_adap[0]);
 246         i2c_set_adapdata(&fc->fc_i2c_adap[1].i2c_adap, &fc->fc_i2c_adap[1]);
 247         i2c_set_adapdata(&fc->fc_i2c_adap[2].i2c_adap, &fc->fc_i2c_adap[2]);
 248
 249         fc->fc_i2c_adap[0].i2c_adap.algo =
 250                 fc->fc_i2c_adap[1].i2c_adap.algo =
 251                 fc->fc_i2c_adap[2].i2c_adap.algo = &flexcop_algo;
 252         fc->fc_i2c_adap[0].i2c_adap.algo_data =
 253                 fc->fc_i2c_adap[1].i2c_adap.algo_data =
 254                 fc->fc_i2c_adap[2].i2c_adap.algo_data = NULL;
 255         fc->fc_i2c_adap[0].i2c_adap.dev.parent =
 256                 fc->fc_i2c_adap[1].i2c_adap.dev.parent =
 257                 fc->fc_i2c_adap[2].i2c_adap.dev.parent = fc->dev;
 258
 259         ret = i2c_add_adapter(&fc->fc_i2c_adap[0].i2c_adap);
 260         if (ret < 0)
 261                 return ret;
 262
 263         ret = i2c_add_adapter(&fc->fc_i2c_adap[1].i2c_adap);
 264         if (ret < 0)
 265                 goto adap_1_failed;
 266
 267         ret = i2c_add_adapter(&fc->fc_i2c_adap[2].i2c_adap);
 268         if (ret < 0)
 269                 goto adap_2_failed;
 270
 271         fc->init_state |= FC_STATE_I2C_INIT;
 272         return 0;
 273
 274 adap_2_failed:
 275         i2c_del_adapter(&fc->fc_i2c_adap[1].i2c_adap);
 276 adap_1_failed:
 277         i2c_del_adapter(&fc->fc_i2c_adap[0].i2c_adap);
 278         return ret;
 279 }
 280
 281 void flexcop_i2c_exit(struct flexcop_device *fc)
 282 {
 283         if (fc->init_state & FC_STATE_I2C_INIT) {
 284                 i2c_del_adapter(&fc->fc_i2c_adap[2].i2c_adap);
 285                 i2c_del_adapter(&fc->fc_i2c_adap[1].i2c_adap);
 286                 i2c_del_adapter(&fc->fc_i2c_adap[0].i2c_adap);
 287         }
 288         fc->init_state &= ~FC_STATE_I2C_INIT;
 289 }