SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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 static int flexcop_i2c_operation(struct flexcop_device *fc, flexcop_ibi_value *r100, int max_ack_errors)
  13 {
  14         int i,ack_errors = 0;
  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) {  /* && !r.tw_sm_c_100.working_start */
  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                         if (++ack_errors >= max_ack_errors)
  35                                 break;
  36
  37                         fc->write_ibi_reg(fc, tw_sm_c_100, ibi_zero);
  38                         fc->write_ibi_reg(fc, tw_sm_c_100, *r100);
  39                 }
  40         }
  41         deb_i2c("tried %d times i2c operation, never finished or too many ack errors.\n",i);
  42         return -EREMOTEIO;
  43 }
  44
  45 static int flexcop_i2c_read4(struct flexcop_device *fc, flexcop_ibi_value r100, u8 *buf)
  46 {
  47         flexcop_ibi_value r104;
  48         int len = r100.tw_sm_c_100.total_bytes, /* remember total_bytes is buflen-1 */
  49                 ret;
  50
  51         if ((ret = flexcop_i2c_operation(fc,&r100,30)) != 0)
  52                 return ret;
  53
  54         r104 = fc->read_ibi_reg(fc,tw_sm_c_104);
  55
  56         deb_i2c("read: r100: %08x, r104: %08x\n",r100.raw,r104.raw);
  57
  58         /* there is at least one byte, otherwise we wouldn't be here */
  59         buf[0] = r100.tw_sm_c_100.data1_reg;
  60
  61         if (len > 0) buf[1] = r104.tw_sm_c_104.data2_reg;
  62         if (len > 1) buf[2] = r104.tw_sm_c_104.data3_reg;
  63         if (len > 2) buf[3] = r104.tw_sm_c_104.data4_reg;
  64
  65         return 0;
  66 }
  67
  68 static int flexcop_i2c_write4(struct flexcop_device *fc, flexcop_ibi_value r100, u8 *buf)
  69 {
  70         flexcop_ibi_value r104;
  71         int len = r100.tw_sm_c_100.total_bytes; /* remember total_bytes is buflen-1 */
  72         r104.raw = 0;
  73
  74         /* there is at least one byte, otherwise we wouldn't be here */
  75         r100.tw_sm_c_100.data1_reg = buf[0];
  76
  77         r104.tw_sm_c_104.data2_reg = len > 0 ? buf[1] : 0;
  78         r104.tw_sm_c_104.data3_reg = len > 1 ? buf[2] : 0;
  79         r104.tw_sm_c_104.data4_reg = len > 2 ? buf[3] : 0;
  80
  81         deb_i2c("write: r100: %08x, r104: %08x\n",r100.raw,r104.raw);
  82
  83         /* write the additional i2c data before doing the actual i2c operation */
  84         fc->write_ibi_reg(fc,tw_sm_c_104,r104);
  85
  86         return flexcop_i2c_operation(fc,&r100,30);
  87 }
  88
  89 /* master xfer callback for demodulator */
  90 static int flexcop_master_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg msgs[], int num)
  91 {
  92         struct flexcop_device *fc = i2c_get_adapdata(i2c_adap);
  93         int i, ret = 0;
  94
  95         if (down_interruptible(&fc->i2c_sem))
  96                 return -ERESTARTSYS;
  97
  98         /* reading */
  99         if (num == 2 &&
 100                 msgs[0].flags == 0 &&
 101                 msgs[1].flags == I2C_M_RD &&
 102                 msgs[0].buf != NULL &&
 103                 msgs[1].buf != NULL) {
 104
 105                 ret = fc->i2c_request(fc, FC_READ, FC_I2C_PORT_DEMOD, msgs[0].addr, msgs[0].buf[0], msgs[1].buf, msgs[1].len);
 106
 107         } else for (i = 0; i < num; i++) { /* writing command */
 108                 if (msgs[i].flags != 0 || msgs[i].buf == NULL || msgs[i].len < 2) {
 109                         ret = -EINVAL;
 110                         break;
 111                 }
 112
 113                 ret = fc->i2c_request(fc, FC_WRITE, FC_I2C_PORT_DEMOD, msgs[i].addr, msgs[i].buf[0], &msgs[i].buf[1], msgs[i].len - 1);
 114         }
 115
 116         if (ret < 0)
 117                 err("i2c master_xfer failed");
 118         else
 119                 ret = num;
 120
 121         up(&fc->i2c_sem);
 122
 123         return ret;
 124 }
 125
 126 int flexcop_i2c_request(struct flexcop_device *fc, flexcop_access_op_t op,
 127                 flexcop_i2c_port_t port, u8 chipaddr, u8 addr, u8 *buf, u16 len)
 128 {
 129         int ret;
 130         u16 bytes_to_transfer;
 131         flexcop_ibi_value r100;
 132
 133         deb_i2c("op = %d\n",op);
 134         r100.raw = 0;
 135         r100.tw_sm_c_100.chipaddr = chipaddr;
 136         r100.tw_sm_c_100.twoWS_rw = op;
 137         r100.tw_sm_c_100.twoWS_port_reg = port;
 138
 139         while (len != 0) {
 140                 bytes_to_transfer = len > 4 ? 4 : len;
 141
 142                 r100.tw_sm_c_100.total_bytes = bytes_to_transfer - 1;
 143                 r100.tw_sm_c_100.baseaddr = addr;
 144
 145                 if (op == FC_READ)
 146                         ret = flexcop_i2c_read4(fc, r100, buf);
 147                 else
 148                         ret = flexcop_i2c_write4(fc,r100, buf);
 149
 150                 if (ret < 0)
 151                         return ret;
 152
 153                 buf  += bytes_to_transfer;
 154                 addr += bytes_to_transfer;
 155                 len  -= bytes_to_transfer;
 156         };
 157
 158         return 0;
 159 }
 160 /* exported for PCI i2c */
 161 EXPORT_SYMBOL(flexcop_i2c_request);
 162
 163 static u32 flexcop_i2c_func(struct i2c_adapter *adapter)
 164 {
 165         return I2C_FUNC_I2C;
 166 }
 167
 168 static struct i2c_algorithm flexcop_algo = {
 169         .name                   = "FlexCop I2C algorithm",
 170         .id                             = I2C_ALGO_BIT,
 171         .master_xfer    = flexcop_master_xfer,
 172         .functionality  = flexcop_i2c_func,
 173 };
 174
 175 int flexcop_i2c_init(struct flexcop_device *fc)
 176 {
 177         int ret;
 178
 179         sema_init(&fc->i2c_sem,1);
 180
 181         memset(&fc->i2c_adap, 0, sizeof(struct i2c_adapter));
 182         strncpy(fc->i2c_adap.name, "B2C2 FlexCop device",I2C_NAME_SIZE);
 183
 184         i2c_set_adapdata(&fc->i2c_adap,fc);
 185
 186         fc->i2c_adap.class          = I2C_CLASS_TV_DIGITAL;
 187         fc->i2c_adap.algo       = &flexcop_algo;
 188         fc->i2c_adap.algo_data  = NULL;
 189         fc->i2c_adap.id         = I2C_ALGO_BIT;
 190
 191         if ((ret = i2c_add_adapter(&fc->i2c_adap)) < 0)
 192                 return ret;
 193
 194         fc->init_state |= FC_STATE_I2C_INIT;
 195         return 0;
 196 }
 197
 198 void flexcop_i2c_exit(struct flexcop_device *fc)
 199 {
 200         if (fc->init_state & FC_STATE_I2C_INIT)
 201                 i2c_del_adapter(&fc->i2c_adap);
 202
 203         fc->init_state &= ~FC_STATE_I2C_INIT;
 204 }