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