[Qemu-devel] [PATCH V4] exynos4210: add Exynos4210 i2c implementation

[Igor Mitsyanko]

Create 9 exynos4210 i2c interfaces.

Signed-off-by: Igor Mitsyanko <address@hidden>
Reviewed-by: Andreas Färber <address@hidden>
---
Previous versions of this patch were sent to mailing list within a "Exynos: 
i2c, gpio and
touchscreen support for NURI board" patchset some time ago. V4 is merely a 
rabased version
of V3.

Change list:

v3->v4
    - rebased to current master.
    - "exynos4210_i2c_info" renamed to "exynos4210_i2c_type_info".

v2->v3
    - static TypeInfos are made const.
    - added spaces after "do {".
    - "All rights reserved" sentence is droped from license.
    - names are fixed according to conventions.
    - introduced scl_free member of exynos4210 i2c state. As it turned out, 
real hardware
      generates level-triggered interrupt while scl line is kept low, scl_free 
member models
      this behaviour. This fixes a bug when i2c generates receiving of extra 
data byte.
    - exynos4210 i2c slave device droped.
    - added missing i2caddr in vmstate.
    - timers are droped.
    - debug array containing i2c registers names replaced with a function.

v1->v2
    - Added indendations for second and subsequent lines of multiple-line macro 
definitions;
    - Weird big spaces after .field members of VMStateDescriptions are replaced 
with single space;

 hw/arm/Makefile.objs |    2 +-
 hw/exynos4210.c      |   27 ++++
 hw/exynos4210.h      |    3 +
 hw/exynos4210_i2c.c  |  334 ++++++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 365 insertions(+), 1 deletions(-)
 create mode 100644 hw/exynos4210_i2c.c

diff --git a/hw/arm/Makefile.objs b/hw/arm/Makefile.objs
index 236786e..c413780 100644
--- a/hw/arm/Makefile.objs
+++ b/hw/arm/Makefile.objs
@@ -11,7 +11,7 @@ obj-y += realview_gic.o realview.o arm_sysctl.o arm11mpcore.o 
a9mpcore.o
 obj-y += exynos4210_gic.o exynos4210_combiner.o exynos4210.o
 obj-y += exynos4_boards.o exynos4210_uart.o exynos4210_pwm.o
 obj-y += exynos4210_pmu.o exynos4210_mct.o exynos4210_fimd.o
-obj-y += exynos4210_rtc.o
+obj-y += exynos4210_rtc.o exynos4210_i2c.o
 obj-y += arm_l2x0.o
 obj-y += arm_mptimer.o a15mpcore.o
 obj-y += armv7m.o armv7m_nvic.o stellaris.o pl022.o stellaris_enet.o
diff --git a/hw/exynos4210.c b/hw/exynos4210.c
index 7c58c90..00d4db8 100644
--- a/hw/exynos4210.c
+++ b/hw/exynos4210.c
@@ -39,6 +39,13 @@
 /* MCT */
 #define EXYNOS4210_MCT_BASE_ADDR       0x10050000
 
+/* I2C */
+#define EXYNOS4210_I2C_SHIFT           0x00010000
+#define EXYNOS4210_I2C_BASE_ADDR       0x13860000
+/* Interrupt Group of External Interrupt Combiner for I2C */
+#define EXYNOS4210_I2C_INTG            27
+#define EXYNOS4210_HDMI_INTG           16
+
 /* UART's definitions */
 #define EXYNOS4210_UART0_BASE_ADDR     0x13800000
 #define EXYNOS4210_UART1_BASE_ADDR     0x13810000
@@ -283,6 +290,26 @@ Exynos4210State *exynos4210_init(MemoryRegion *system_mem,
             s->irq_table[exynos4210_get_irq(35, 3)]);
     sysbus_mmio_map(busdev, 0, EXYNOS4210_MCT_BASE_ADDR);
 
+    /*** I2C ***/
+    for (n = 0; n < EXYNOS4210_I2C_NUMBER; n++) {
+        uint32_t addr = EXYNOS4210_I2C_BASE_ADDR + EXYNOS4210_I2C_SHIFT * n;
+        qemu_irq i2c_irq;
+
+        if (n < 8) {
+            i2c_irq = s->irq_table[exynos4210_get_irq(EXYNOS4210_I2C_INTG, n)];
+        } else {
+            i2c_irq = s->irq_table[exynos4210_get_irq(EXYNOS4210_HDMI_INTG, 
1)];
+        }
+
+        dev = qdev_create(NULL, "exynos4210.i2c");
+        qdev_init_nofail(dev);
+        busdev = sysbus_from_qdev(dev);
+        sysbus_connect_irq(busdev, 0, i2c_irq);
+        sysbus_mmio_map(busdev, 0, addr);
+        s->i2c_if[n] = (i2c_bus *)qdev_get_child_bus(dev, "i2c");
+    }
+
+
     /*** UARTs ***/
     exynos4210_uart_create(EXYNOS4210_UART0_BASE_ADDR,
                            EXYNOS4210_UART0_FIFO_SIZE, 0, NULL,
diff --git a/hw/exynos4210.h b/hw/exynos4210.h
index 9b1ae4c..a43ba3a 100644
--- a/hw/exynos4210.h
+++ b/hw/exynos4210.h
@@ -74,6 +74,8 @@
 #define EXYNOS4210_EXT_GIC_NIRQ     (160-32)
 #define EXYNOS4210_INT_GIC_NIRQ     64
 
+#define EXYNOS4210_I2C_NUMBER               9
+
 typedef struct Exynos4210Irq {
     qemu_irq int_combiner_irq[EXYNOS4210_MAX_INT_COMBINER_IN_IRQ];
     qemu_irq ext_combiner_irq[EXYNOS4210_MAX_EXT_COMBINER_IN_IRQ];
@@ -95,6 +97,7 @@ typedef struct Exynos4210State {
     MemoryRegion dram1_mem;
     MemoryRegion boot_secondary;
     MemoryRegion bootreg_mem;
+    i2c_bus *i2c_if[EXYNOS4210_I2C_NUMBER];
 } Exynos4210State;
 
 void exynos4210_write_secondary(ARMCPU *cpu,
diff --git a/hw/exynos4210_i2c.c b/hw/exynos4210_i2c.c
new file mode 100644
index 0000000..3f72a5c
--- /dev/null
+++ b/hw/exynos4210_i2c.c
@@ -0,0 +1,334 @@
+/*
+ *  Exynos4210 I2C Bus Serial Interface Emulation
+ *
+ *  Copyright (C) 2012 Samsung Electronics Co Ltd.
+ *    Maksim Kozlov, <address@hidden>
+ *    Igor Mitsyanko, <address@hidden>
+ *
+ *  This program is free software; you can redistribute it and/or modify it
+ *  under the terms of the GNU General Public License as published by the
+ *  Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful, but WITHOUT
+ *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ *  FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ *  for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "qemu-timer.h"
+#include "sysbus.h"
+#include "i2c.h"
+
+#ifndef EXYNOS4_I2C_DEBUG
+#define EXYNOS4_I2C_DEBUG                 0
+#endif
+
+#define TYPE_EXYNOS4_I2C                  "exynos4210.i2c"
+#define EXYNOS4_I2C(obj)                  \
+    OBJECT_CHECK(Exynos4210I2CState, (obj), TYPE_EXYNOS4_I2C)
+
+/* Exynos4210 I2C memory map */
+#define EXYNOS4_I2C_MEM_SIZE              0x14
+#define I2CCON_ADDR                       0x00  /* control register */
+#define I2CSTAT_ADDR                      0x04  /* control/status register */
+#define I2CADD_ADDR                       0x08  /* address register */
+#define I2CDS_ADDR                        0x0c  /* data shift register */
+#define I2CLC_ADDR                        0x10  /* line control register */
+
+#define I2CCON_ACK_GEN                    (1 << 7)
+#define I2CCON_INTRS_EN                   (1 << 5)
+#define I2CCON_INT_PEND                   (1 << 4)
+
+#define EXYNOS4_I2C_MODE(reg)             (((reg) >> 6) & 3)
+#define I2C_IN_MASTER_MODE(reg)           (((reg) >> 6) & 2)
+#define I2CMODE_MASTER_Rx                 0x2
+#define I2CMODE_MASTER_Tx                 0x3
+#define I2CSTAT_LAST_BIT                  (1 << 0)
+#define I2CSTAT_OUTPUT_EN                 (1 << 4)
+#define I2CSTAT_START_BUSY                (1 << 5)
+
+
+#if EXYNOS4_I2C_DEBUG
+#define DPRINT(fmt, args...)              \
+    do { fprintf(stderr, "QEMU I2C: "fmt, ## args); } while (0)
+
+static const char *exynos4_i2c_get_regname(unsigned offset)
+{
+    switch (offset) {
+    case I2CCON_ADDR:
+        return "I2CCON";
+    case I2CSTAT_ADDR:
+        return "I2CSTAT";
+    case I2CADD_ADDR:
+        return "I2CADD";
+    case I2CDS_ADDR:
+        return "I2CDS";
+    case I2CLC_ADDR:
+        return "I2CLC";
+    default:
+        return "[?]";
+    }
+}
+
+#else
+#define DPRINT(fmt, args...)              do { } while (0)
+#endif
+
+typedef struct Exynos4210I2CState {
+    SysBusDevice busdev;
+    MemoryRegion iomem;
+    i2c_bus *bus;
+    qemu_irq irq;
+
+    uint8_t i2ccon;
+    uint8_t i2cstat;
+    uint8_t i2cadd;
+    uint8_t i2cds;
+    uint8_t i2clc;
+    bool scl_free;
+} Exynos4210I2CState;
+
+static inline void exynos4210_i2c_raise_interrupt(Exynos4210I2CState *s)
+{
+    if (s->i2ccon & I2CCON_INTRS_EN) {
+        s->i2ccon |= I2CCON_INT_PEND;
+        qemu_irq_raise(s->irq);
+    }
+}
+
+static void exynos4210_i2c_data_receive(void *opaque)
+{
+    Exynos4210I2CState *s = (Exynos4210I2CState *)opaque;
+    int ret;
+
+    s->i2cstat &= ~I2CSTAT_LAST_BIT;
+    s->scl_free = false;
+    ret = i2c_recv(s->bus);
+    if (ret < 0 && (s->i2ccon & I2CCON_ACK_GEN)) {
+        s->i2cstat |= I2CSTAT_LAST_BIT;  /* Data is not acknowledged */
+    } else {
+        s->i2cds = ret;
+    }
+    exynos4210_i2c_raise_interrupt(s);
+}
+
+static void exynos4210_i2c_data_send(void *opaque)
+{
+    Exynos4210I2CState *s = (Exynos4210I2CState *)opaque;
+
+    s->i2cstat &= ~I2CSTAT_LAST_BIT;
+    s->scl_free = false;
+    if (i2c_send(s->bus, s->i2cds) < 0 && (s->i2ccon & I2CCON_ACK_GEN)) {
+        s->i2cstat |= I2CSTAT_LAST_BIT;
+    }
+    exynos4210_i2c_raise_interrupt(s);
+}
+
+static uint64_t exynos4210_i2c_read(void *opaque, target_phys_addr_t offset,
+                                 unsigned size)
+{
+    Exynos4210I2CState *s = (Exynos4210I2CState *)opaque;
+    uint8_t value;
+
+    switch (offset) {
+    case I2CCON_ADDR:
+        value = s->i2ccon;
+        break;
+    case I2CSTAT_ADDR:
+        value = s->i2cstat;
+        break;
+    case I2CADD_ADDR:
+        value = s->i2cadd;
+        break;
+    case I2CDS_ADDR:
+        value = s->i2cds;
+        s->scl_free = true;
+        if (EXYNOS4_I2C_MODE(s->i2cstat) == I2CMODE_MASTER_Rx &&
+               (s->i2cstat & I2CSTAT_START_BUSY) &&
+               !(s->i2ccon & I2CCON_INT_PEND)) {
+            exynos4210_i2c_data_receive(s);
+        }
+        break;
+    case I2CLC_ADDR:
+        value = s->i2clc;
+        break;
+    default:
+        value = 0;
+        DPRINT("ERROR: Bad read offset 0x%x\n", (unsigned int)offset);
+        break;
+    }
+
+    DPRINT("read %s [0x%02x] -> 0x%02x\n", exynos4_i2c_get_regname(offset),
+            (unsigned int)offset, value);
+    return value;
+}
+
+static void exynos4210_i2c_write(void *opaque, target_phys_addr_t offset,
+                              uint64_t value, unsigned size)
+{
+    Exynos4210I2CState *s = (Exynos4210I2CState *)opaque;
+    uint8_t v = value & 0xff;
+
+    DPRINT("write %s [0x%02x] <- 0x%02x\n", exynos4_i2c_get_regname(offset),
+            (unsigned int)offset, v);
+
+    switch (offset) {
+    case I2CCON_ADDR:
+        s->i2ccon = (v & ~I2CCON_INT_PEND) | (s->i2ccon & I2CCON_INT_PEND);
+        if ((s->i2ccon & I2CCON_INT_PEND) && !(v & I2CCON_INT_PEND)) {
+            s->i2ccon &= ~I2CCON_INT_PEND;
+            qemu_irq_lower(s->irq);
+            if (!(s->i2ccon & I2CCON_INTRS_EN)) {
+                s->i2cstat &= ~I2CSTAT_START_BUSY;
+            }
+
+            if (s->i2cstat & I2CSTAT_START_BUSY) {
+                if (s->scl_free) {
+                    if (EXYNOS4_I2C_MODE(s->i2cstat) == I2CMODE_MASTER_Tx) {
+                        exynos4210_i2c_data_send(s);
+                    } else if (EXYNOS4_I2C_MODE(s->i2cstat) ==
+                            I2CMODE_MASTER_Rx) {
+                        exynos4210_i2c_data_receive(s);
+                    }
+                } else {
+                    s->i2ccon |= I2CCON_INT_PEND;
+                    qemu_irq_raise(s->irq);
+                }
+            }
+        }
+        break;
+    case I2CSTAT_ADDR:
+        s->i2cstat =
+                (s->i2cstat & I2CSTAT_START_BUSY) | (v & ~I2CSTAT_START_BUSY);
+
+        if (!(s->i2cstat & I2CSTAT_OUTPUT_EN)) {
+            s->i2cstat &= ~I2CSTAT_START_BUSY;
+            s->scl_free = true;
+            qemu_irq_lower(s->irq);
+            break;
+        }
+
+        /* Nothing to do if in i2c slave mode */
+        if (!I2C_IN_MASTER_MODE(s->i2cstat)) {
+            break;
+        }
+
+        if (v & I2CSTAT_START_BUSY) {
+            s->i2cstat &= ~I2CSTAT_LAST_BIT;
+            s->i2cstat |= I2CSTAT_START_BUSY;    /* Line is busy */
+            s->scl_free = false;
+
+            /* Generate start bit and send slave address */
+            if (i2c_start_transfer(s->bus, s->i2cds >> 1, s->i2cds & 0x1) &&
+                    (s->i2ccon & I2CCON_ACK_GEN)) {
+                s->i2cstat |= I2CSTAT_LAST_BIT;
+            } else if (EXYNOS4_I2C_MODE(s->i2cstat) == I2CMODE_MASTER_Rx) {
+                exynos4210_i2c_data_receive(s);
+            }
+            exynos4210_i2c_raise_interrupt(s);
+        } else {
+            i2c_end_transfer(s->bus);
+            if (!(s->i2ccon & I2CCON_INT_PEND)) {
+                s->i2cstat &= ~I2CSTAT_START_BUSY;
+            }
+            s->scl_free = true;
+        }
+        break;
+    case I2CADD_ADDR:
+        if ((s->i2cstat & I2CSTAT_OUTPUT_EN) == 0) {
+            s->i2cadd = v;
+        }
+        break;
+    case I2CDS_ADDR:
+        if (s->i2cstat & I2CSTAT_OUTPUT_EN) {
+            s->i2cds = v;
+            s->scl_free = true;
+            if (EXYNOS4_I2C_MODE(s->i2cstat) == I2CMODE_MASTER_Tx &&
+                    (s->i2cstat & I2CSTAT_START_BUSY) &&
+                    !(s->i2ccon & I2CCON_INT_PEND)) {
+                exynos4210_i2c_data_send(s);
+            }
+        }
+        break;
+    case I2CLC_ADDR:
+        s->i2clc = v;
+        break;
+    default:
+        DPRINT("ERROR: Bad write offset 0x%x\n", (unsigned int)offset);
+        break;
+    }
+}
+
+static const MemoryRegionOps exynos4210_i2c_ops = {
+    .read = exynos4210_i2c_read,
+    .write = exynos4210_i2c_write,
+    .endianness = DEVICE_NATIVE_ENDIAN,
+};
+
+static const VMStateDescription exynos4210_i2c_vmstate = {
+    .name = TYPE_EXYNOS4_I2C,
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT8(i2ccon, Exynos4210I2CState),
+        VMSTATE_UINT8(i2cstat, Exynos4210I2CState),
+        VMSTATE_UINT8(i2cds, Exynos4210I2CState),
+        VMSTATE_UINT8(i2cadd, Exynos4210I2CState),
+        VMSTATE_UINT8(i2clc, Exynos4210I2CState),
+        VMSTATE_BOOL(scl_free, Exynos4210I2CState),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static void exynos4210_i2c_reset(DeviceState *d)
+{
+    Exynos4210I2CState *s = EXYNOS4_I2C(d);
+
+    s->i2ccon  = 0x00;
+    s->i2cstat = 0x00;
+    s->i2cds   = 0xFF;
+    s->i2clc   = 0x00;
+    s->i2cadd  = 0xFF;
+    s->scl_free = true;
+}
+
+static int exynos4210_i2c_realize(SysBusDevice *dev)
+{
+    Exynos4210I2CState *s = EXYNOS4_I2C(dev);
+
+    memory_region_init_io(&s->iomem, &exynos4210_i2c_ops, s, TYPE_EXYNOS4_I2C,
+                          EXYNOS4_I2C_MEM_SIZE);
+    sysbus_init_mmio(dev, &s->iomem);
+    sysbus_init_irq(dev, &s->irq);
+    s->bus = i2c_init_bus(&dev->qdev, "i2c");
+    return 0;
+}
+
+static void exynos4210_i2c_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    SysBusDeviceClass *sbdc = SYS_BUS_DEVICE_CLASS(klass);
+
+    dc->vmsd = &exynos4210_i2c_vmstate;
+    dc->reset = exynos4210_i2c_reset;
+    sbdc->init = exynos4210_i2c_realize;
+}
+
+static const TypeInfo exynos4210_i2c_type_info = {
+    .name = TYPE_EXYNOS4_I2C,
+    .parent = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(Exynos4210I2CState),
+    .class_init = exynos4210_i2c_class_init,
+};
+
+static void exynos4210_i2c_register_types(void)
+{
+    type_register_static(&exynos4210_i2c_type_info);
+}
+
+type_init(exynos4210_i2c_register_types)
-- 
1.7.5.4