drivers/i2c/ihs_i2c.c

   1 /*
   2  * (C) Copyright 2013
   3  * Dirk Eibach,  Guntermann & Drunck GmbH, eibach@gdsys.de
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 #include <common.h>
   9 #include <i2c.h>
  10 #include <gdsys_fpga.h>
  11
  12 DECLARE_GLOBAL_DATA_PTR;
  13
  14 #ifdef CONFIG_SYS_I2C_IHS_DUAL
  15 #define I2C_SET_REG(fld, val) \
  16         do { \
  17                 if (I2C_ADAP_HWNR & 0x10) \
  18                         FPGA_SET_REG(I2C_ADAP_HWNR & 0xf, i2c1.fld, val); \
  19                 else \
  20                         FPGA_SET_REG(I2C_ADAP_HWNR, i2c0.fld, val); \
  21         } while (0)
  22 #else
  23 #define I2C_SET_REG(fld, val) \
  24                 FPGA_SET_REG(I2C_ADAP_HWNR, i2c0.fld, val)
  25 #endif
  26
  27 #ifdef CONFIG_SYS_I2C_IHS_DUAL
  28 #define I2C_GET_REG(fld, val) \
  29         do {                                    \
  30                 if (I2C_ADAP_HWNR & 0x10) \
  31                         FPGA_GET_REG(I2C_ADAP_HWNR & 0xf, i2c1.fld, val); \
  32                 else \
  33                         FPGA_GET_REG(I2C_ADAP_HWNR, i2c0.fld, val); \
  34         } while (0)
  35 #else
  36 #define I2C_GET_REG(fld, val) \
  37                 FPGA_GET_REG(I2C_ADAP_HWNR, i2c0.fld, val)
  38 #endif
  39
  40 enum {
  41         I2CINT_ERROR_EV = 1 << 13,
  42         I2CINT_TRANSMIT_EV = 1 << 14,
  43         I2CINT_RECEIVE_EV = 1 << 15,
  44 };
  45
  46 enum {
  47         I2CMB_WRITE = 1 << 10,
  48         I2CMB_2BYTE = 1 << 11,
  49         I2CMB_HOLD_BUS = 1 << 13,
  50         I2CMB_NATIVE = 2 << 14,
  51 };
  52
  53 static int wait_for_int(bool read)
  54 {
  55         u16 val;
  56         unsigned int ctr = 0;
  57
  58         I2C_GET_REG(interrupt_status, &val);
  59         while (!(val & (I2CINT_ERROR_EV
  60                | (read ? I2CINT_RECEIVE_EV : I2CINT_TRANSMIT_EV)))) {
  61                 udelay(10);
  62                 if (ctr++ > 5000) {
  63                         return 1;
  64                 }
  65                 I2C_GET_REG(interrupt_status, &val);
  66         }
  67
  68         return (val & I2CINT_ERROR_EV) ? 1 : 0;
  69 }
  70
  71 static int ihs_i2c_transfer(uchar chip, uchar *buffer, int len, bool read,
  72                             bool is_last)
  73 {
  74         u16 val;
  75
  76         I2C_SET_REG(interrupt_status, I2CINT_ERROR_EV
  77                      | I2CINT_RECEIVE_EV | I2CINT_TRANSMIT_EV);
  78         I2C_GET_REG(interrupt_status, &val);
  79
  80         if (!read && len) {
  81                 val = buffer[0];
  82
  83                 if (len > 1)
  84                         val |= buffer[1] << 8;
  85                 I2C_SET_REG(write_mailbox_ext, val);
  86         }
  87
  88         I2C_SET_REG(write_mailbox,
  89                     I2CMB_NATIVE
  90                     | (read ? 0 : I2CMB_WRITE)
  91                     | (chip << 1)
  92                     | ((len > 1) ? I2CMB_2BYTE : 0)
  93                     | (is_last ? 0 : I2CMB_HOLD_BUS));
  94
  95         if (wait_for_int(read))
  96                 return 1;
  97
  98         if (read) {
  99                 I2C_GET_REG(read_mailbox_ext, &val);
 100                 buffer[0] = val & 0xff;
 101                 if (len > 1)
 102                         buffer[1] = val >> 8;
 103         }
 104
 105         return 0;
 106 }
 107
 108 static int ihs_i2c_address(uchar chip, uint addr, int alen, bool hold_bus)
 109 {
 110         int shift = (alen-1) * 8;
 111
 112         while (alen) {
 113                 int transfer = min(alen, 2);
 114                 uchar buf[2];
 115                 bool is_last = alen <= transfer;
 116
 117                 buf[0] = addr >> shift;
 118                 if (alen > 1)
 119                         buf[1] = addr >> (shift - 8);
 120
 121                 if (ihs_i2c_transfer(chip, buf, transfer, false,
 122                                      hold_bus ? false : is_last))
 123                         return 1;
 124
 125                 shift -= 16;
 126                 alen -= transfer;
 127         }
 128
 129         return 0;
 130 }
 131
 132 static int ihs_i2c_access(struct i2c_adapter *adap, uchar chip, uint addr,
 133                           int alen, uchar *buffer, int len, bool read)
 134 {
 135         if (len <= 0)
 136                 return 1;
 137
 138         if (ihs_i2c_address(chip, addr, alen, !read))
 139                 return 1;
 140
 141         while (len) {
 142                 int transfer = min(len, 2);
 143
 144                 if (ihs_i2c_transfer(chip, buffer, transfer, read,
 145                                      len <= transfer))
 146                         return 1;
 147
 148                 buffer += transfer;
 149                 addr += transfer;
 150                 len -= transfer;
 151         }
 152
 153         return 0;
 154 }
 155
 156
 157 static void ihs_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr)
 158 {
 159 #ifdef CONFIG_SYS_I2C_INIT_BOARD
 160         /*
 161          * Call board specific i2c bus reset routine before accessing the
 162          * environment, which might be in a chip on that bus. For details
 163          * about this problem see doc/I2C_Edge_Conditions.
 164          */
 165         i2c_init_board();
 166 #endif
 167 }
 168
 169 static int ihs_i2c_probe(struct i2c_adapter *adap, uchar chip)
 170 {
 171         uchar buffer[2];
 172
 173         if (ihs_i2c_transfer(chip, buffer, 0, true, true))
 174                 return 1;
 175
 176         return 0;
 177 }
 178
 179 static int ihs_i2c_read(struct i2c_adapter *adap, uchar chip, uint addr,
 180                         int alen, uchar *buffer, int len)
 181 {
 182         return ihs_i2c_access(adap, chip, addr, alen, buffer, len, true);
 183 }
 184
 185 static int ihs_i2c_write(struct i2c_adapter *adap, uchar chip, uint addr,
 186                          int alen, uchar *buffer, int len)
 187 {
 188         return ihs_i2c_access(adap, chip, addr, alen, buffer, len, false);
 189 }
 190
 191 static unsigned int ihs_i2c_set_bus_speed(struct i2c_adapter *adap,
 192                                           unsigned int speed)
 193 {
 194         if (speed != adap->speed)
 195                 return 1;
 196         return speed;
 197 }
 198
 199 /*
 200  * Register IHS i2c adapters
 201  */
 202 #ifdef CONFIG_SYS_I2C_IHS_CH0
 203 U_BOOT_I2C_ADAP_COMPLETE(ihs0, ihs_i2c_init, ihs_i2c_probe,
 204                          ihs_i2c_read, ihs_i2c_write,
 205                          ihs_i2c_set_bus_speed,
 206                          CONFIG_SYS_I2C_IHS_SPEED_0,
 207                          CONFIG_SYS_I2C_IHS_SLAVE_0, 0)
 208 #ifdef CONFIG_SYS_I2C_IHS_DUAL
 209 U_BOOT_I2C_ADAP_COMPLETE(ihs0_1, ihs_i2c_init, ihs_i2c_probe,
 210                          ihs_i2c_read, ihs_i2c_write,
 211                          ihs_i2c_set_bus_speed,
 212                          CONFIG_SYS_I2C_IHS_SPEED_0_1,
 213                          CONFIG_SYS_I2C_IHS_SLAVE_0_1, 16)
 214 #endif
 215 #endif
 216 #ifdef CONFIG_SYS_I2C_IHS_CH1
 217 U_BOOT_I2C_ADAP_COMPLETE(ihs1, ihs_i2c_init, ihs_i2c_probe,
 218                          ihs_i2c_read, ihs_i2c_write,
 219                          ihs_i2c_set_bus_speed,
 220                          CONFIG_SYS_I2C_IHS_SPEED_1,
 221                          CONFIG_SYS_I2C_IHS_SLAVE_1, 1)
 222 #ifdef CONFIG_SYS_I2C_IHS_DUAL
 223 U_BOOT_I2C_ADAP_COMPLETE(ihs1_1, ihs_i2c_init, ihs_i2c_probe,
 224                          ihs_i2c_read, ihs_i2c_write,
 225                          ihs_i2c_set_bus_speed,
 226                          CONFIG_SYS_I2C_IHS_SPEED_1_1,
 227                          CONFIG_SYS_I2C_IHS_SLAVE_1_1, 17)
 228 #endif
 229 #endif
 230 #ifdef CONFIG_SYS_I2C_IHS_CH2
 231 U_BOOT_I2C_ADAP_COMPLETE(ihs2, ihs_i2c_init, ihs_i2c_probe,
 232                          ihs_i2c_read, ihs_i2c_write,
 233                          ihs_i2c_set_bus_speed,
 234                          CONFIG_SYS_I2C_IHS_SPEED_2,
 235                          CONFIG_SYS_I2C_IHS_SLAVE_2, 2)
 236 #ifdef CONFIG_SYS_I2C_IHS_DUAL
 237 U_BOOT_I2C_ADAP_COMPLETE(ihs2_1, ihs_i2c_init, ihs_i2c_probe,
 238                          ihs_i2c_read, ihs_i2c_write,
 239                          ihs_i2c_set_bus_speed,
 240                          CONFIG_SYS_I2C_IHS_SPEED_2_1,
 241                          CONFIG_SYS_I2C_IHS_SLAVE_2_1, 18)
 242 #endif
 243 #endif
 244 #ifdef CONFIG_SYS_I2C_IHS_CH3
 245 U_BOOT_I2C_ADAP_COMPLETE(ihs3, ihs_i2c_init, ihs_i2c_probe,
 246                          ihs_i2c_read, ihs_i2c_write,
 247                          ihs_i2c_set_bus_speed,
 248                          CONFIG_SYS_I2C_IHS_SPEED_3,
 249                          CONFIG_SYS_I2C_IHS_SLAVE_3, 3)
 250 #ifdef CONFIG_SYS_I2C_IHS_DUAL
 251 U_BOOT_I2C_ADAP_COMPLETE(ihs3_1, ihs_i2c_init, ihs_i2c_probe,
 252                          ihs_i2c_read, ihs_i2c_write,
 253                          ihs_i2c_set_bus_speed,
 254                          CONFIG_SYS_I2C_IHS_SPEED_3_1,
 255                          CONFIG_SYS_I2C_IHS_SLAVE_3_1, 19)
 256 #endif
 257 #endif