LXR linux/drivers/media/common/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
  10static 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
  41static 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
  86static 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
 106int 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 */
 172EXPORT_SYMBOL(flexcop_i2c_request);
 173
 174/* master xfer callback for demodulator */
 175static 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
 215static u32 flexcop_i2c_func(struct i2c_adapter *adapter)
 216{
 217        return I2C_FUNC_I2C;
 218}
 219
 220static struct i2c_algorithm flexcop_algo = {
 221        .master_xfer    = flexcop_master_xfer,
 222        .functionality  = flexcop_i2c_func,
 223};
 224
 225int 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
 273adap_2_failed:
 274        i2c_del_adapter(&fc->fc_i2c_adap[1].i2c_adap);
 275adap_1_failed:
 276        i2c_del_adapter(&fc->fc_i2c_adap[0].i2c_adap);
 277        return ret;
 278}
 279
 280void 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}
 289