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/*
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 * TI OMAP on-chip I2C controller.  Only "new I2C" mode supported.
3
 *
4
 * Copyright (C) 2007 Andrzej Zaborowski  <balrog@zabor.org>
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 *
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 * This program is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU General Public License as
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 * published by the Free Software Foundation; either version 2 of
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 * the License, or (at your option) any later version.
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 *
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 * This program is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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 * GNU General Public License for more details.
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 *
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 * You should have received a copy of the GNU General Public License along
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 * with this program; if not, see <http://www.gnu.org/licenses/>.
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 */
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#include "hw.h"
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#include "i2c.h"
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#include "omap.h"
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#include "sysbus.h"
23

    
24

    
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typedef struct OMAPI2CState {
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    SysBusDevice busdev;
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    MemoryRegion iomem;
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    qemu_irq irq;
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    qemu_irq drq[2];
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    i2c_bus *bus;
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    uint8_t revision;
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    void *iclk;
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    void *fclk;
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    uint8_t mask;
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    uint16_t stat;
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    uint16_t dma;
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    uint16_t count;
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    int count_cur;
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    uint32_t fifo;
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    int rxlen;
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    int txlen;
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    uint16_t control;
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    uint16_t addr[2];
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    uint8_t divider;
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    uint8_t times[2];
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    uint16_t test;
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} OMAPI2CState;
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#define OMAP2_INTR_REV        0x34
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#define OMAP2_GC_REV        0x34
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static void omap_i2c_interrupts_update(OMAPI2CState *s)
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{
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    qemu_set_irq(s->irq, s->stat & s->mask);
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    if ((s->dma >> 15) & 1)                                        /* RDMA_EN */
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        qemu_set_irq(s->drq[0], (s->stat >> 3) & 1);                /* RRDY */
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    if ((s->dma >> 7) & 1)                                        /* XDMA_EN */
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        qemu_set_irq(s->drq[1], (s->stat >> 4) & 1);                /* XRDY */
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}
62

    
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static void omap_i2c_fifo_run(OMAPI2CState *s)
64
{
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    int ack = 1;
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    if (!i2c_bus_busy(s->bus))
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        return;
69

    
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    if ((s->control >> 2) & 1) {                                /* RM */
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        if ((s->control >> 1) & 1) {                                /* STP */
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            i2c_end_transfer(s->bus);
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            s->control &= ~(1 << 1);                                /* STP */
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            s->count_cur = s->count;
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            s->txlen = 0;
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        } else if ((s->control >> 9) & 1) {                        /* TRX */
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            while (ack && s->txlen)
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                ack = (i2c_send(s->bus,
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                                        (s->fifo >> ((-- s->txlen) << 3)) &
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                                        0xff) >= 0);
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            s->stat |= 1 << 4;                                        /* XRDY */
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        } else {
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            while (s->rxlen < 4)
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                s->fifo |= i2c_recv(s->bus) << ((s->rxlen ++) << 3);
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            s->stat |= 1 << 3;                                        /* RRDY */
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        }
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    } else {
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        if ((s->control >> 9) & 1) {                                /* TRX */
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            while (ack && s->count_cur && s->txlen) {
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                ack = (i2c_send(s->bus,
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                                        (s->fifo >> ((-- s->txlen) << 3)) &
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                                        0xff) >= 0);
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                s->count_cur --;
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            }
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            if (ack && s->count_cur)
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                s->stat |= 1 << 4;                                /* XRDY */
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            else
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                s->stat &= ~(1 << 4);                                /* XRDY */
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            if (!s->count_cur) {
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                s->stat |= 1 << 2;                                /* ARDY */
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                s->control &= ~(1 << 10);                        /* MST */
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            }
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        } else {
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            while (s->count_cur && s->rxlen < 4) {
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                s->fifo |= i2c_recv(s->bus) << ((s->rxlen ++) << 3);
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                s->count_cur --;
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            }
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            if (s->rxlen)
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                s->stat |= 1 << 3;                                /* RRDY */
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            else
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                s->stat &= ~(1 << 3);                                /* RRDY */
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        }
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        if (!s->count_cur) {
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            if ((s->control >> 1) & 1) {                        /* STP */
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                i2c_end_transfer(s->bus);
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                s->control &= ~(1 << 1);                        /* STP */
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                s->count_cur = s->count;
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                s->txlen = 0;
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            } else {
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                s->stat |= 1 << 2;                                /* ARDY */
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                s->control &= ~(1 << 10);                        /* MST */
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            }
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        }
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    }
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    s->stat |= (!ack) << 1;                                        /* NACK */
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    if (!ack)
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        s->control &= ~(1 << 1);                                /* STP */
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}
130

    
131
static void omap_i2c_reset(DeviceState *dev)
132
{
133
    OMAPI2CState *s = FROM_SYSBUS(OMAPI2CState,
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                                  sysbus_from_qdev(dev));
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    s->mask = 0;
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    s->stat = 0;
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    s->dma = 0;
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    s->count = 0;
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    s->count_cur = 0;
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    s->fifo = 0;
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    s->rxlen = 0;
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    s->txlen = 0;
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    s->control = 0;
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    s->addr[0] = 0;
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    s->addr[1] = 0;
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    s->divider = 0;
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    s->times[0] = 0;
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    s->times[1] = 0;
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    s->test = 0;
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}
151

    
152
static uint32_t omap_i2c_read(void *opaque, hwaddr addr)
153
{
154
    OMAPI2CState *s = opaque;
155
    int offset = addr & OMAP_MPUI_REG_MASK;
156
    uint16_t ret;
157

    
158
    switch (offset) {
159
    case 0x00:        /* I2C_REV */
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        return s->revision;                                        /* REV */
161

    
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    case 0x04:        /* I2C_IE */
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        return s->mask;
164

    
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    case 0x08:        /* I2C_STAT */
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        return s->stat | (i2c_bus_busy(s->bus) << 12);
167

    
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    case 0x0c:        /* I2C_IV */
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        if (s->revision >= OMAP2_INTR_REV)
170
            break;
171
        ret = ffs(s->stat & s->mask);
172
        if (ret)
173
            s->stat ^= 1 << (ret - 1);
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        omap_i2c_interrupts_update(s);
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        return ret;
176

    
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    case 0x10:        /* I2C_SYSS */
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        return (s->control >> 15) & 1;                                /* I2C_EN */
179

    
180
    case 0x14:        /* I2C_BUF */
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        return s->dma;
182

    
183
    case 0x18:        /* I2C_CNT */
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        return s->count_cur;                                        /* DCOUNT */
185

    
186
    case 0x1c:        /* I2C_DATA */
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        ret = 0;
188
        if (s->control & (1 << 14)) {                                /* BE */
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            ret |= ((s->fifo >> 0) & 0xff) << 8;
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            ret |= ((s->fifo >> 8) & 0xff) << 0;
191
        } else {
192
            ret |= ((s->fifo >> 8) & 0xff) << 8;
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            ret |= ((s->fifo >> 0) & 0xff) << 0;
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        }
195
        if (s->rxlen == 1) {
196
            s->stat |= 1 << 15;                                        /* SBD */
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            s->rxlen = 0;
198
        } else if (s->rxlen > 1) {
199
            if (s->rxlen > 2)
200
                s->fifo >>= 16;
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            s->rxlen -= 2;
202
        } else {
203
            /* XXX: remote access (qualifier) error - what's that?  */
204
        }
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        if (!s->rxlen) {
206
            s->stat &= ~(1 << 3);                                /* RRDY */
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            if (((s->control >> 10) & 1) &&                        /* MST */
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                            ((~s->control >> 9) & 1)) {                /* TRX */
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                s->stat |= 1 << 2;                                /* ARDY */
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                s->control &= ~(1 << 10);                        /* MST */
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            }
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        }
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        s->stat &= ~(1 << 11);                                        /* ROVR */
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        omap_i2c_fifo_run(s);
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        omap_i2c_interrupts_update(s);
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        return ret;
217

    
218
    case 0x20:        /* I2C_SYSC */
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        return 0;
220

    
221
    case 0x24:        /* I2C_CON */
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        return s->control;
223

    
224
    case 0x28:        /* I2C_OA */
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        return s->addr[0];
226

    
227
    case 0x2c:        /* I2C_SA */
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        return s->addr[1];
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230
    case 0x30:        /* I2C_PSC */
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        return s->divider;
232

    
233
    case 0x34:        /* I2C_SCLL */
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        return s->times[0];
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236
    case 0x38:        /* I2C_SCLH */
237
        return s->times[1];
238

    
239
    case 0x3c:        /* I2C_SYSTEST */
240
        if (s->test & (1 << 15)) {                                /* ST_EN */
241
            s->test ^= 0xa;
242
            return s->test;
243
        } else
244
            return s->test & ~0x300f;
245
    }
246

    
247
    OMAP_BAD_REG(addr);
248
    return 0;
249
}
250

    
251
static void omap_i2c_write(void *opaque, hwaddr addr,
252
                uint32_t value)
253
{
254
    OMAPI2CState *s = opaque;
255
    int offset = addr & OMAP_MPUI_REG_MASK;
256
    int nack;
257

    
258
    switch (offset) {
259
    case 0x00:        /* I2C_REV */
260
    case 0x0c:        /* I2C_IV */
261
    case 0x10:        /* I2C_SYSS */
262
        OMAP_RO_REG(addr);
263
        return;
264

    
265
    case 0x04:        /* I2C_IE */
266
        s->mask = value & (s->revision < OMAP2_GC_REV ? 0x1f : 0x3f);
267
        break;
268

    
269
    case 0x08:        /* I2C_STAT */
270
        if (s->revision < OMAP2_INTR_REV) {
271
            OMAP_RO_REG(addr);
272
            return;
273
        }
274

    
275
        /* RRDY and XRDY are reset by hardware. (in all versions???) */
276
        s->stat &= ~(value & 0x27);
277
        omap_i2c_interrupts_update(s);
278
        break;
279

    
280
    case 0x14:        /* I2C_BUF */
281
        s->dma = value & 0x8080;
282
        if (value & (1 << 15))                                        /* RDMA_EN */
283
            s->mask &= ~(1 << 3);                                /* RRDY_IE */
284
        if (value & (1 << 7))                                        /* XDMA_EN */
285
            s->mask &= ~(1 << 4);                                /* XRDY_IE */
286
        break;
287

    
288
    case 0x18:        /* I2C_CNT */
289
        s->count = value;                                        /* DCOUNT */
290
        break;
291

    
292
    case 0x1c:        /* I2C_DATA */
293
        if (s->txlen > 2) {
294
            /* XXX: remote access (qualifier) error - what's that?  */
295
            break;
296
        }
297
        s->fifo <<= 16;
298
        s->txlen += 2;
299
        if (s->control & (1 << 14)) {                                /* BE */
300
            s->fifo |= ((value >> 8) & 0xff) << 8;
301
            s->fifo |= ((value >> 0) & 0xff) << 0;
302
        } else {
303
            s->fifo |= ((value >> 0) & 0xff) << 8;
304
            s->fifo |= ((value >> 8) & 0xff) << 0;
305
        }
306
        s->stat &= ~(1 << 10);                                        /* XUDF */
307
        if (s->txlen > 2)
308
            s->stat &= ~(1 << 4);                                /* XRDY */
309
        omap_i2c_fifo_run(s);
310
        omap_i2c_interrupts_update(s);
311
        break;
312

    
313
    case 0x20:        /* I2C_SYSC */
314
        if (s->revision < OMAP2_INTR_REV) {
315
            OMAP_BAD_REG(addr);
316
            return;
317
        }
318

    
319
        if (value & 2)
320
            omap_i2c_reset(&s->busdev.qdev);
321
        break;
322

    
323
    case 0x24:        /* I2C_CON */
324
        s->control = value & 0xcf87;
325
        if (~value & (1 << 15)) {                                /* I2C_EN */
326
            if (s->revision < OMAP2_INTR_REV)
327
                omap_i2c_reset(&s->busdev.qdev);
328
            break;
329
        }
330
        if ((value & (1 << 15)) && !(value & (1 << 10))) {        /* MST */
331
            fprintf(stderr, "%s: I^2C slave mode not supported\n",
332
                            __FUNCTION__);
333
            break;
334
        }
335
        if ((value & (1 << 15)) && value & (1 << 8)) {                /* XA */
336
            fprintf(stderr, "%s: 10-bit addressing mode not supported\n",
337
                            __FUNCTION__);
338
            break;
339
        }
340
        if ((value & (1 << 15)) && value & (1 << 0)) {                /* STT */
341
            nack = !!i2c_start_transfer(s->bus, s->addr[1],        /* SA */
342
                            (~value >> 9) & 1);                        /* TRX */
343
            s->stat |= nack << 1;                                /* NACK */
344
            s->control &= ~(1 << 0);                                /* STT */
345
            s->fifo = 0;
346
            if (nack)
347
                s->control &= ~(1 << 1);                        /* STP */
348
            else {
349
                s->count_cur = s->count;
350
                omap_i2c_fifo_run(s);
351
            }
352
            omap_i2c_interrupts_update(s);
353
        }
354
        break;
355

    
356
    case 0x28:        /* I2C_OA */
357
        s->addr[0] = value & 0x3ff;
358
        break;
359

    
360
    case 0x2c:        /* I2C_SA */
361
        s->addr[1] = value & 0x3ff;
362
        break;
363

    
364
    case 0x30:        /* I2C_PSC */
365
        s->divider = value;
366
        break;
367

    
368
    case 0x34:        /* I2C_SCLL */
369
        s->times[0] = value;
370
        break;
371

    
372
    case 0x38:        /* I2C_SCLH */
373
        s->times[1] = value;
374
        break;
375

    
376
    case 0x3c:        /* I2C_SYSTEST */
377
        s->test = value & 0xf80f;
378
        if (value & (1 << 11))                                        /* SBB */
379
            if (s->revision >= OMAP2_INTR_REV) {
380
                s->stat |= 0x3f;
381
                omap_i2c_interrupts_update(s);
382
            }
383
        if (value & (1 << 15))                                        /* ST_EN */
384
            fprintf(stderr, "%s: System Test not supported\n", __FUNCTION__);
385
        break;
386

    
387
    default:
388
        OMAP_BAD_REG(addr);
389
        return;
390
    }
391
}
392

    
393
static void omap_i2c_writeb(void *opaque, hwaddr addr,
394
                uint32_t value)
395
{
396
    OMAPI2CState *s = opaque;
397
    int offset = addr & OMAP_MPUI_REG_MASK;
398

    
399
    switch (offset) {
400
    case 0x1c:        /* I2C_DATA */
401
        if (s->txlen > 2) {
402
            /* XXX: remote access (qualifier) error - what's that?  */
403
            break;
404
        }
405
        s->fifo <<= 8;
406
        s->txlen += 1;
407
        s->fifo |= value & 0xff;
408
        s->stat &= ~(1 << 10);                                        /* XUDF */
409
        if (s->txlen > 2)
410
            s->stat &= ~(1 << 4);                                /* XRDY */
411
        omap_i2c_fifo_run(s);
412
        omap_i2c_interrupts_update(s);
413
        break;
414

    
415
    default:
416
        OMAP_BAD_REG(addr);
417
        return;
418
    }
419
}
420

    
421
static const MemoryRegionOps omap_i2c_ops = {
422
    .old_mmio = {
423
        .read = {
424
            omap_badwidth_read16,
425
            omap_i2c_read,
426
            omap_badwidth_read16,
427
        },
428
        .write = {
429
            omap_i2c_writeb, /* Only the last fifo write can be 8 bit.  */
430
            omap_i2c_write,
431
            omap_badwidth_write16,
432
        },
433
    },
434
    .endianness = DEVICE_NATIVE_ENDIAN,
435
};
436

    
437
static int omap_i2c_init(SysBusDevice *dev)
438
{
439
    OMAPI2CState *s = FROM_SYSBUS(OMAPI2CState, dev);
440

    
441
    if (!s->fclk) {
442
        hw_error("omap_i2c: fclk not connected\n");
443
    }
444
    if (s->revision >= OMAP2_INTR_REV && !s->iclk) {
445
        /* Note that OMAP1 doesn't have a separate interface clock */
446
        hw_error("omap_i2c: iclk not connected\n");
447
    }
448
    sysbus_init_irq(dev, &s->irq);
449
    sysbus_init_irq(dev, &s->drq[0]);
450
    sysbus_init_irq(dev, &s->drq[1]);
451
    memory_region_init_io(&s->iomem, &omap_i2c_ops, s, "omap.i2c",
452
                          (s->revision < OMAP2_INTR_REV) ? 0x800 : 0x1000);
453
    sysbus_init_mmio(dev, &s->iomem);
454
    s->bus = i2c_init_bus(&dev->qdev, NULL);
455
    return 0;
456
}
457

    
458
static Property omap_i2c_properties[] = {
459
    DEFINE_PROP_UINT8("revision", OMAPI2CState, revision, 0),
460
    DEFINE_PROP_PTR("iclk", OMAPI2CState, iclk),
461
    DEFINE_PROP_PTR("fclk", OMAPI2CState, fclk),
462
    DEFINE_PROP_END_OF_LIST(),
463
};
464

    
465
static void omap_i2c_class_init(ObjectClass *klass, void *data)
466
{
467
    DeviceClass *dc = DEVICE_CLASS(klass);
468
    SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
469
    k->init = omap_i2c_init;
470
    dc->props = omap_i2c_properties;
471
    dc->reset = omap_i2c_reset;
472
}
473

    
474
static TypeInfo omap_i2c_info = {
475
    .name = "omap_i2c",
476
    .parent = TYPE_SYS_BUS_DEVICE,
477
    .instance_size = sizeof(OMAPI2CState),
478
    .class_init = omap_i2c_class_init,
479
};
480

    
481
static void omap_i2c_register_types(void)
482
{
483
    type_register_static(&omap_i2c_info);
484
}
485

    
486
i2c_bus *omap_i2c_bus(DeviceState *omap_i2c)
487
{
488
    OMAPI2CState *s = FROM_SYSBUS(OMAPI2CState, sysbus_from_qdev(omap_i2c));
489
    return s->bus;
490
}
491

    
492
type_init(omap_i2c_register_types)