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 "libqos/i2c.h"
  10
  11 #include <glib.h>
  12 #include <string.h>
  13
  14 #include "qemu/osdep.h"
  15 #include "qemu/bswap.h"
  16 #include "libqtest.h"
  17
  18 enum OMAPI2CRegisters {
  19     OMAP_I2C_REV  = 0x00,
  20     OMAP_I2C_STAT = 0x08,
  21     OMAP_I2C_CNT  = 0x18,
  22     OMAP_I2C_DATA = 0x1c,
  23     OMAP_I2C_CON  = 0x24,
  24     OMAP_I2C_SA   = 0x2c,
  25 };
  26
  27 enum OMAPI2CSTATBits {
  28     OMAP_I2C_STAT_NACK = 1 << 1,
  29     OMAP_I2C_STAT_ARDY = 1 << 2,
  30     OMAP_I2C_STAT_RRDY = 1 << 3,
  31     OMAP_I2C_STAT_XRDY = 1 << 4,
  32     OMAP_I2C_STAT_ROVR = 1 << 11,
  33     OMAP_I2C_STAT_SBD  = 1 << 15,
  34 };
  35
  36 enum OMAPI2CCONBits {
  37     OMAP_I2C_CON_STT    = 1 << 0,
  38     OMAP_I2C_CON_STP    = 1 << 1,
  39     OMAP_I2C_CON_TRX    = 1 << 9,
  40     OMAP_I2C_CON_MST    = 1 << 10,
  41     OMAP_I2C_CON_BE     = 1 << 14,
  42     OMAP_I2C_CON_I2C_EN = 1 << 15,
  43 };
  44
  45 typedef struct OMAPI2C {
  46     I2CAdapter parent;
  47
  48     uint64_t addr;
  49 } OMAPI2C;
  50
  51
  52 static void omap_i2c_set_slave_addr(OMAPI2C *s, uint8_t addr)
  53 {
  54     uint16_t data = addr;
  55
  56     writew(s->addr + OMAP_I2C_SA, data);
  57     data = readw(s->addr + OMAP_I2C_SA);
  58     g_assert_cmphex(data, ==, addr);
  59 }
  60
  61 static void omap_i2c_send(I2CAdapter *i2c, uint8_t addr,
  62                           const uint8_t *buf, uint16_t len)
  63 {
  64     OMAPI2C *s = (OMAPI2C *)i2c;
  65     uint16_t data;
  66
  67     omap_i2c_set_slave_addr(s, addr);
  68
  69     data = len;
  70     writew(s->addr + OMAP_I2C_CNT, data);
  71
  72     data = OMAP_I2C_CON_I2C_EN |
  73            OMAP_I2C_CON_TRX |
  74            OMAP_I2C_CON_MST |
  75            OMAP_I2C_CON_STT |
  76            OMAP_I2C_CON_STP;
  77     writew(s->addr + OMAP_I2C_CON, data);
  78     data = readw(s->addr + OMAP_I2C_CON);
  79     g_assert((data & OMAP_I2C_CON_STP) != 0);
  80
  81     data = readw(s->addr + OMAP_I2C_STAT);
  82     g_assert((data & OMAP_I2C_STAT_NACK) == 0);
  83
  84     while (len > 1) {
  85         data = readw(s->addr + OMAP_I2C_STAT);
  86         g_assert((data & OMAP_I2C_STAT_XRDY) != 0);
  87
  88         data = buf[0] | ((uint16_t)buf[1] << 8);
  89         writew(s->addr + OMAP_I2C_DATA, data);
  90         buf = (uint8_t *)buf + 2;
  91         len -= 2;
  92     }
  93     if (len == 1) {
  94         data = readw(s->addr + OMAP_I2C_STAT);
  95         g_assert((data & OMAP_I2C_STAT_XRDY) != 0);
  96
  97         data = buf[0];
  98         writew(s->addr + OMAP_I2C_DATA, data);
  99     }
 100
 101     data = readw(s->addr + OMAP_I2C_CON);
 102     g_assert((data & OMAP_I2C_CON_STP) == 0);
 103 }
 104
 105 static void omap_i2c_recv(I2CAdapter *i2c, uint8_t addr,
 106                           uint8_t *buf, uint16_t len)
 107 {
 108     OMAPI2C *s = (OMAPI2C *)i2c;
 109     uint16_t data, stat;
 110
 111     omap_i2c_set_slave_addr(s, addr);
 112
 113     data = len;
 114     writew(s->addr + OMAP_I2C_CNT, data);
 115
 116     data = OMAP_I2C_CON_I2C_EN |
 117            OMAP_I2C_CON_MST |
 118            OMAP_I2C_CON_STT |
 119            OMAP_I2C_CON_STP;
 120     writew(s->addr + OMAP_I2C_CON, data);
 121     data = readw(s->addr + OMAP_I2C_CON);
 122     g_assert((data & OMAP_I2C_CON_STP) == 0);
 123
 124     data = readw(s->addr + OMAP_I2C_STAT);
 125     g_assert((data & OMAP_I2C_STAT_NACK) == 0);
 126
 127     data = readw(s->addr + OMAP_I2C_CNT);
 128     g_assert_cmpuint(data, ==, len);
 129
 130     while (len > 0) {
 131         data = readw(s->addr + OMAP_I2C_STAT);
 132         g_assert((data & OMAP_I2C_STAT_RRDY) != 0);
 133         g_assert((data & OMAP_I2C_STAT_ROVR) == 0);
 134
 135         data = readw(s->addr + OMAP_I2C_DATA);
 136
 137         stat = readw(s->addr + OMAP_I2C_STAT);
 138
 139         if (unlikely(len == 1)) {
 140             g_assert((stat & OMAP_I2C_STAT_SBD) != 0);
 141
 142             buf[0] = data & 0xff;
 143             buf++;
 144             len--;
 145         } else {
 146             buf[0] = data & 0xff;
 147             buf[1] = data >> 8;
 148             buf += 2;
 149             len -= 2;
 150         }
 151     }
 152
 153     data = readw(s->addr + OMAP_I2C_CON);
 154     g_assert((data & OMAP_I2C_CON_STP) == 0);
 155 }
 156
 157 I2CAdapter *omap_i2c_create(uint64_t addr)
 158 {
 159     OMAPI2C *s = g_malloc0(sizeof(*s));
 160     I2CAdapter *i2c = (I2CAdapter *)s;
 161     uint16_t data;
 162
 163     s->addr = addr;
 164
 165     i2c->send = omap_i2c_send;
 166     i2c->recv = omap_i2c_recv;
 167
 168     /* verify the mmio address by looking for a known signature */
 169     data = readw(addr + OMAP_I2C_REV);
 170     g_assert_cmphex(data, ==, 0x34);
 171
 172     return i2c;
 173 }