tests/libqos/i2c-omap.c

   1 /*
   2  * QTest I2C driver
   3  *
   4  * Copyright (c) 2012 Andreas Färber
   5  *
   6  * This work is licensed under the terms of the GNU GPL, version 2 or later.
   7  * See the COPYING file in the top-level directory.
   8  */
   9 #include "qemu/osdep.h"
  10 #include "libqos/i2c.h"
  11
  12
  13 #include "qemu/bswap.h"
  14 #include "libqtest.h"
  15
  16 enum OMAPI2CRegisters {
  17     OMAP_I2C_REV  = 0x00,
  18     OMAP_I2C_STAT = 0x08,
  19     OMAP_I2C_CNT  = 0x18,
  20     OMAP_I2C_DATA = 0x1c,
  21     OMAP_I2C_CON  = 0x24,
  22     OMAP_I2C_SA   = 0x2c,
  23 };
  24
  25 enum OMAPI2CSTATBits {
  26     OMAP_I2C_STAT_NACK = 1 << 1,
  27     OMAP_I2C_STAT_ARDY = 1 << 2,
  28     OMAP_I2C_STAT_RRDY = 1 << 3,
  29     OMAP_I2C_STAT_XRDY = 1 << 4,
  30     OMAP_I2C_STAT_ROVR = 1 << 11,
  31     OMAP_I2C_STAT_SBD  = 1 << 15,
  32 };
  33
  34 enum OMAPI2CCONBits {
  35     OMAP_I2C_CON_STT    = 1 << 0,
  36     OMAP_I2C_CON_STP    = 1 << 1,
  37     OMAP_I2C_CON_TRX    = 1 << 9,
  38     OMAP_I2C_CON_MST    = 1 << 10,
  39     OMAP_I2C_CON_BE     = 1 << 14,
  40     OMAP_I2C_CON_I2C_EN = 1 << 15,
  41 };
  42
  43 typedef struct OMAPI2C {
  44     I2CAdapter parent;
  45
  46     uint64_t addr;
  47 } OMAPI2C;
  48
  49
  50 static void omap_i2c_set_slave_addr(OMAPI2C *s, uint8_t addr)
  51 {
  52     uint16_t data = addr;
  53
  54     writew(s->addr + OMAP_I2C_SA, data);
  55     data = readw(s->addr + OMAP_I2C_SA);
  56     g_assert_cmphex(data, ==, addr);
  57 }
  58
  59 static void omap_i2c_send(I2CAdapter *i2c, uint8_t addr,
  60                           const uint8_t *buf, uint16_t len)
  61 {
  62     OMAPI2C *s = (OMAPI2C *)i2c;
  63     uint16_t data;
  64
  65     omap_i2c_set_slave_addr(s, addr);
  66
  67     data = len;
  68     writew(s->addr + OMAP_I2C_CNT, data);
  69
  70     data = OMAP_I2C_CON_I2C_EN |
  71            OMAP_I2C_CON_TRX |
  72            OMAP_I2C_CON_MST |
  73            OMAP_I2C_CON_STT |
  74            OMAP_I2C_CON_STP;
  75     writew(s->addr + OMAP_I2C_CON, data);
  76     data = readw(s->addr + OMAP_I2C_CON);
  77     g_assert((data & OMAP_I2C_CON_STP) != 0);
  78
  79     data = readw(s->addr + OMAP_I2C_STAT);
  80     g_assert((data & OMAP_I2C_STAT_NACK) == 0);
  81
  82     while (len > 1) {
  83         data = readw(s->addr + OMAP_I2C_STAT);
  84         g_assert((data & OMAP_I2C_STAT_XRDY) != 0);
  85
  86         data = buf[0] | ((uint16_t)buf[1] << 8);
  87         writew(s->addr + OMAP_I2C_DATA, data);
  88         buf = (uint8_t *)buf + 2;
  89         len -= 2;
  90     }
  91     if (len == 1) {
  92         data = readw(s->addr + OMAP_I2C_STAT);
  93         g_assert((data & OMAP_I2C_STAT_XRDY) != 0);
  94
  95         data = buf[0];
  96         writew(s->addr + OMAP_I2C_DATA, data);
  97     }
  98
  99     data = readw(s->addr + OMAP_I2C_CON);
 100     g_assert((data & OMAP_I2C_CON_STP) == 0);
 101 }
 102
 103 static void omap_i2c_recv(I2CAdapter *i2c, uint8_t addr,
 104                           uint8_t *buf, uint16_t len)
 105 {
 106     OMAPI2C *s = (OMAPI2C *)i2c;
 107     uint16_t data, stat;
 108
 109     omap_i2c_set_slave_addr(s, addr);
 110
 111     data = len;
 112     writew(s->addr + OMAP_I2C_CNT, data);
 113
 114     data = OMAP_I2C_CON_I2C_EN |
 115            OMAP_I2C_CON_MST |
 116            OMAP_I2C_CON_STT |
 117            OMAP_I2C_CON_STP;
 118     writew(s->addr + OMAP_I2C_CON, data);
 119     data = readw(s->addr + OMAP_I2C_CON);
 120     g_assert((data & OMAP_I2C_CON_STP) == 0);
 121
 122     data = readw(s->addr + OMAP_I2C_STAT);
 123     g_assert((data & OMAP_I2C_STAT_NACK) == 0);
 124
 125     data = readw(s->addr + OMAP_I2C_CNT);
 126     g_assert_cmpuint(data, ==, len);
 127
 128     while (len > 0) {
 129         data = readw(s->addr + OMAP_I2C_STAT);
 130         g_assert((data & OMAP_I2C_STAT_RRDY) != 0);
 131         g_assert((data & OMAP_I2C_STAT_ROVR) == 0);
 132
 133         data = readw(s->addr + OMAP_I2C_DATA);
 134
 135         stat = readw(s->addr + OMAP_I2C_STAT);
 136
 137         if (unlikely(len == 1)) {
 138             g_assert((stat & OMAP_I2C_STAT_SBD) != 0);
 139
 140             buf[0] = data & 0xff;
 141             buf++;
 142             len--;
 143         } else {
 144             buf[0] = data & 0xff;
 145             buf[1] = data >> 8;
 146             buf += 2;
 147             len -= 2;
 148         }
 149     }
 150
 151     data = readw(s->addr + OMAP_I2C_CON);
 152     g_assert((data & OMAP_I2C_CON_STP) == 0);
 153 }
 154
 155 I2CAdapter *omap_i2c_create(uint64_t addr)
 156 {
 157     OMAPI2C *s = g_malloc0(sizeof(*s));
 158     I2CAdapter *i2c = (I2CAdapter *)s;
 159     uint16_t data;
 160
 161     s->addr = addr;
 162
 163     i2c->send = omap_i2c_send;
 164     i2c->recv = omap_i2c_recv;
 165
 166     /* verify the mmio address by looking for a known signature */
 167     data = readw(addr + OMAP_I2C_REV);
 168     g_assert_cmphex(data, ==, 0x34);
 169
 170     return i2c;
 171 }