tests/libqos/i2c-imx.c

   1 /*
   2  * QTest i.MX I2C driver
   3  *
   4  * Copyright (c) 2013 Jean-Christophe Dubois
   5  *
   6  *  This program is free software; you can redistribute it and/or modify it
   7  *  under the terms of the GNU General Public License as published by the
   8  *  Free Software Foundation; either version 2 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful, but WITHOUT
  12  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  *  FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
  14  *  for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License along
  17  *  with this program; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include "qemu/osdep.h"
  21 #include "libqos/i2c.h"
  22
  23
  24 #include "libqtest.h"
  25
  26 #include "hw/i2c/imx_i2c.h"
  27
  28 enum IMXI2CDirection {
  29     IMX_I2C_READ,
  30     IMX_I2C_WRITE,
  31 };
  32
  33 typedef struct IMXI2C {
  34     I2CAdapter parent;
  35
  36     uint64_t addr;
  37 } IMXI2C;
  38
  39
  40 static void imx_i2c_set_slave_addr(IMXI2C *s, uint8_t addr,
  41                                    enum IMXI2CDirection direction)
  42 {
  43     writeb(s->addr + I2DR_ADDR, (addr << 1) |
  44            (direction == IMX_I2C_READ ? 1 : 0));
  45 }
  46
  47 static void imx_i2c_send(I2CAdapter *i2c, uint8_t addr,
  48                          const uint8_t *buf, uint16_t len)
  49 {
  50     IMXI2C *s = (IMXI2C *)i2c;
  51     uint8_t data;
  52     uint8_t status;
  53     uint16_t size = 0;
  54
  55     if (!len) {
  56         return;
  57     }
  58
  59     /* set the bus for write */
  60     data = I2CR_IEN |
  61            I2CR_IIEN |
  62            I2CR_MSTA |
  63            I2CR_MTX |
  64            I2CR_TXAK;
  65
  66     writeb(s->addr + I2CR_ADDR, data);
  67     status = readb(s->addr + I2SR_ADDR);
  68     g_assert((status & I2SR_IBB) != 0);
  69
  70     /* set the slave address */
  71     imx_i2c_set_slave_addr(s, addr, IMX_I2C_WRITE);
  72     status = readb(s->addr + I2SR_ADDR);
  73     g_assert((status & I2SR_IIF) != 0);
  74     g_assert((status & I2SR_RXAK) == 0);
  75
  76     /* ack the interrupt */
  77     writeb(s->addr + I2SR_ADDR, 0);
  78     status = readb(s->addr + I2SR_ADDR);
  79     g_assert((status & I2SR_IIF) == 0);
  80
  81     while (size < len) {
  82         /* check we are still busy */
  83         status = readb(s->addr + I2SR_ADDR);
  84         g_assert((status & I2SR_IBB) != 0);
  85
  86         /* write the data */
  87         writeb(s->addr + I2DR_ADDR, buf[size]);
  88         status = readb(s->addr + I2SR_ADDR);
  89         g_assert((status & I2SR_IIF) != 0);
  90         g_assert((status & I2SR_RXAK) == 0);
  91
  92         /* ack the interrupt */
  93         writeb(s->addr + I2SR_ADDR, 0);
  94         status = readb(s->addr + I2SR_ADDR);
  95         g_assert((status & I2SR_IIF) == 0);
  96
  97         size++;
  98     }
  99
 100     /* release the bus */
 101     data &= ~(I2CR_MSTA | I2CR_MTX);
 102     writeb(s->addr + I2CR_ADDR, data);
 103     status = readb(s->addr + I2SR_ADDR);
 104     g_assert((status & I2SR_IBB) == 0);
 105 }
 106
 107 static void imx_i2c_recv(I2CAdapter *i2c, uint8_t addr,
 108                          uint8_t *buf, uint16_t len)
 109 {
 110     IMXI2C *s = (IMXI2C *)i2c;
 111     uint8_t data;
 112     uint8_t status;
 113     uint16_t size = 0;
 114
 115     if (!len) {
 116         return;
 117     }
 118
 119     /* set the bus for write */
 120     data = I2CR_IEN |
 121            I2CR_IIEN |
 122            I2CR_MSTA |
 123            I2CR_MTX |
 124            I2CR_TXAK;
 125
 126     writeb(s->addr + I2CR_ADDR, data);
 127     status = readb(s->addr + I2SR_ADDR);
 128     g_assert((status & I2SR_IBB) != 0);
 129
 130     /* set the slave address */
 131     imx_i2c_set_slave_addr(s, addr, IMX_I2C_READ);
 132     status = readb(s->addr + I2SR_ADDR);
 133     g_assert((status & I2SR_IIF) != 0);
 134     g_assert((status & I2SR_RXAK) == 0);
 135
 136     /* ack the interrupt */
 137     writeb(s->addr + I2SR_ADDR, 0);
 138     status = readb(s->addr + I2SR_ADDR);
 139     g_assert((status & I2SR_IIF) == 0);
 140
 141     /* set the bus for read */
 142     data &= ~I2CR_MTX;
 143     /* if only one byte don't ack */
 144     if (len != 1) {
 145         data &= ~I2CR_TXAK;
 146     }
 147     writeb(s->addr + I2CR_ADDR, data);
 148     status = readb(s->addr + I2SR_ADDR);
 149     g_assert((status & I2SR_IBB) != 0);
 150
 151     /* dummy read */
 152     readb(s->addr + I2DR_ADDR);
 153     status = readb(s->addr + I2SR_ADDR);
 154     g_assert((status & I2SR_IIF) != 0);
 155
 156     /* ack the interrupt */
 157     writeb(s->addr + I2SR_ADDR, 0);
 158     status = readb(s->addr + I2SR_ADDR);
 159     g_assert((status & I2SR_IIF) == 0);
 160
 161     while (size < len) {
 162         /* check we are still busy */
 163         status = readb(s->addr + I2SR_ADDR);
 164         g_assert((status & I2SR_IBB) != 0);
 165
 166         if (size == (len - 1)) {
 167             /* stop the read transaction */
 168             data &= ~(I2CR_MSTA | I2CR_MTX);
 169         } else {
 170             /* ack the data read */
 171             data |= I2CR_TXAK;
 172         }
 173         writeb(s->addr + I2CR_ADDR, data);
 174
 175         /* read the data */
 176         buf[size] = readb(s->addr + I2DR_ADDR);
 177
 178         if (size != (len - 1)) {
 179             status = readb(s->addr + I2SR_ADDR);
 180             g_assert((status & I2SR_IIF) != 0);
 181
 182             /* ack the interrupt */
 183             writeb(s->addr + I2SR_ADDR, 0);
 184         }
 185
 186         status = readb(s->addr + I2SR_ADDR);
 187         g_assert((status & I2SR_IIF) == 0);
 188
 189         size++;
 190     }
 191
 192     status = readb(s->addr + I2SR_ADDR);
 193     g_assert((status & I2SR_IBB) == 0);
 194 }
 195
 196 I2CAdapter *imx_i2c_create(uint64_t addr)
 197 {
 198     IMXI2C *s = g_malloc0(sizeof(*s));
 199     I2CAdapter *i2c = (I2CAdapter *)s;
 200
 201     s->addr = addr;
 202
 203     i2c->send = imx_i2c_send;
 204     i2c->recv = imx_i2c_recv;
 205
 206     return i2c;
 207 }