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Diffstat (limited to 'hw/i2c/imx_i2c.c')
-rw-r--r--hw/i2c/imx_i2c.c334
1 files changed, 334 insertions, 0 deletions
diff --git a/hw/i2c/imx_i2c.c b/hw/i2c/imx_i2c.c
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index 0000000000..8474872e07
--- /dev/null
+++ b/hw/i2c/imx_i2c.c
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+/*
+ * i.MX I2C Bus Serial Interface Emulation
+ *
+ * Copyright (C) 2013 Jean-Christophe Dubois. <jcd@tribudubois.net>
+ *
+ * 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 "hw/i2c/imx_i2c.h"
+#include "hw/i2c/i2c.h"
+
+#ifndef IMX_I2C_DEBUG
+#define IMX_I2C_DEBUG 0
+#endif
+
+#if IMX_I2C_DEBUG
+#define DPRINT(fmt, args...) \
+ do { fprintf(stderr, "%s: "fmt, __func__, ## args); } while (0)
+
+static const char *imx_i2c_get_regname(unsigned offset)
+{
+ switch (offset) {
+ case IADR_ADDR:
+ return "IADR";
+ case IFDR_ADDR:
+ return "IFDR";
+ case I2CR_ADDR:
+ return "I2CR";
+ case I2SR_ADDR:
+ return "I2SR";
+ case I2DR_ADDR:
+ return "I2DR";
+ default:
+ return "[?]";
+ }
+}
+#else
+#define DPRINT(fmt, args...) do { } while (0)
+#endif
+
+static inline bool imx_i2c_is_enabled(IMXI2CState *s)
+{
+ return s->i2cr & I2CR_IEN;
+}
+
+static inline bool imx_i2c_interrupt_is_enabled(IMXI2CState *s)
+{
+ return s->i2cr & I2CR_IIEN;
+}
+
+static inline bool imx_i2c_is_master(IMXI2CState *s)
+{
+ return s->i2cr & I2CR_MSTA;
+}
+
+static void imx_i2c_reset(DeviceState *dev)
+{
+ IMXI2CState *s = IMX_I2C(dev);
+
+ if (s->address != ADDR_RESET) {
+ i2c_end_transfer(s->bus);
+ }
+
+ s->address = ADDR_RESET;
+ s->iadr = IADR_RESET;
+ s->ifdr = IFDR_RESET;
+ s->i2cr = I2CR_RESET;
+ s->i2sr = I2SR_RESET;
+ s->i2dr_read = I2DR_RESET;
+ s->i2dr_write = I2DR_RESET;
+}
+
+static inline void imx_i2c_raise_interrupt(IMXI2CState *s)
+{
+ /*
+ * raise an interrupt if the device is enabled and it is configured
+ * to generate some interrupts.
+ */
+ if (imx_i2c_is_enabled(s) && imx_i2c_interrupt_is_enabled(s)) {
+ s->i2sr |= I2SR_IIF;
+ qemu_irq_raise(s->irq);
+ }
+}
+
+static uint64_t imx_i2c_read(void *opaque, hwaddr offset,
+ unsigned size)
+{
+ uint16_t value;
+ IMXI2CState *s = IMX_I2C(opaque);
+
+ switch (offset) {
+ case IADR_ADDR:
+ value = s->iadr;
+ break;
+ case IFDR_ADDR:
+ value = s->ifdr;
+ break;
+ case I2CR_ADDR:
+ value = s->i2cr;
+ break;
+ case I2SR_ADDR:
+ value = s->i2sr;
+ break;
+ case I2DR_ADDR:
+ value = s->i2dr_read;
+
+ if (imx_i2c_is_master(s)) {
+ int ret = 0xff;
+
+ if (s->address == ADDR_RESET) {
+ /* something is wrong as the address is not set */
+ qemu_log_mask(LOG_GUEST_ERROR, "%s[%s]: Trying to read "
+ "without specifying the slave address\n",
+ TYPE_IMX_I2C, __func__);
+ } else if (s->i2cr & I2CR_MTX) {
+ qemu_log_mask(LOG_GUEST_ERROR, "%s[%s]: Trying to read "
+ "but MTX is set\n", TYPE_IMX_I2C, __func__);
+ } else {
+ /* get the next byte */
+ ret = i2c_recv(s->bus);
+
+ if (ret >= 0) {
+ imx_i2c_raise_interrupt(s);
+ } else {
+ qemu_log_mask(LOG_GUEST_ERROR, "%s[%s]: read failed "
+ "for device 0x%02x\n", TYPE_IMX_I2C,
+ __func__, s->address);
+ ret = 0xff;
+ }
+ }
+
+ s->i2dr_read = ret;
+ } else {
+ qemu_log_mask(LOG_UNIMP, "%s[%s]: slave mode not implemented\n",
+ TYPE_IMX_I2C, __func__);
+ }
+ break;
+ default:
+ qemu_log_mask(LOG_GUEST_ERROR, "%s[%s]: Bad address at offset %d\n",
+ TYPE_IMX_I2C, __func__, s->address);
+ value = 0;
+ break;
+ }
+
+ DPRINT("read %s [0x%02x] -> 0x%02x\n", imx_i2c_get_regname(offset),
+ (unsigned int)offset, value);
+
+ return (uint64_t)value;
+}
+
+static void imx_i2c_write(void *opaque, hwaddr offset,
+ uint64_t value, unsigned size)
+{
+ IMXI2CState *s = IMX_I2C(opaque);
+
+ DPRINT("write %s [0x%02x] <- 0x%02x\n", imx_i2c_get_regname(offset),
+ (unsigned int)offset, (int)value);
+
+ value &= 0xff;
+
+ switch (offset) {
+ case IADR_ADDR:
+ s->iadr = value & IADR_MASK;
+ /* i2c_set_slave_address(s->bus, (uint8_t)s->iadr); */
+ break;
+ case IFDR_ADDR:
+ s->ifdr = value & IFDR_MASK;
+ break;
+ case I2CR_ADDR:
+ if (imx_i2c_is_enabled(s) && ((value & I2CR_IEN) == 0)) {
+ /* This is a soft reset. IADR is preserved during soft resets */
+ uint16_t iadr = s->iadr;
+ imx_i2c_reset(DEVICE(s));
+ s->iadr = iadr;
+ } else { /* normal write */
+ s->i2cr = value & I2CR_MASK;
+
+ if (imx_i2c_is_master(s)) {
+ /* set the bus to busy */
+ s->i2sr |= I2SR_IBB;
+ } else { /* slave mode */
+ /* bus is not busy anymore */
+ s->i2sr &= ~I2SR_IBB;
+
+ /*
+ * if we unset the master mode then it ends the ongoing
+ * transfer if any
+ */
+ if (s->address != ADDR_RESET) {
+ i2c_end_transfer(s->bus);
+ s->address = ADDR_RESET;
+ }
+ }
+
+ if (s->i2cr & I2CR_RSTA) { /* Restart */
+ /* if this is a restart then it ends the ongoing transfer */
+ if (s->address != ADDR_RESET) {
+ i2c_end_transfer(s->bus);
+ s->address = ADDR_RESET;
+ s->i2cr &= ~I2CR_RSTA;
+ }
+ }
+ }
+ break;
+ case I2SR_ADDR:
+ /*
+ * if the user writes 0 to IIF then lower the interrupt and
+ * reset the bit
+ */
+ if ((s->i2sr & I2SR_IIF) && !(value & I2SR_IIF)) {
+ s->i2sr &= ~I2SR_IIF;
+ qemu_irq_lower(s->irq);
+ }
+
+ /*
+ * if the user writes 0 to IAL, reset the bit
+ */
+ if ((s->i2sr & I2SR_IAL) && !(value & I2SR_IAL)) {
+ s->i2sr &= ~I2SR_IAL;
+ }
+
+ break;
+ case I2DR_ADDR:
+ /* if the device is not enabled, nothing to do */
+ if (!imx_i2c_is_enabled(s)) {
+ break;
+ }
+
+ s->i2dr_write = value & I2DR_MASK;
+
+ if (imx_i2c_is_master(s)) {
+ /* If this is the first write cycle then it is the slave addr */
+ if (s->address == ADDR_RESET) {
+ if (i2c_start_transfer(s->bus, extract32(s->i2dr_write, 1, 7),
+ extract32(s->i2dr_write, 0, 1))) {
+ /* if non zero is returned, the adress is not valid */
+ s->i2sr |= I2SR_RXAK;
+ } else {
+ s->address = s->i2dr_write;
+ s->i2sr &= ~I2SR_RXAK;
+ imx_i2c_raise_interrupt(s);
+ }
+ } else { /* This is a normal data write */
+ if (i2c_send(s->bus, s->i2dr_write)) {
+ /* if the target return non zero then end the transfer */
+ s->i2sr |= I2SR_RXAK;
+ s->address = ADDR_RESET;
+ i2c_end_transfer(s->bus);
+ } else {
+ s->i2sr &= ~I2SR_RXAK;
+ imx_i2c_raise_interrupt(s);
+ }
+ }
+ } else {
+ qemu_log_mask(LOG_UNIMP, "%s[%s]: slave mode not implemented\n",
+ TYPE_IMX_I2C, __func__);
+ }
+ break;
+ default:
+ qemu_log_mask(LOG_GUEST_ERROR, "%s[%s]: Bad address at offset %d\n",
+ TYPE_IMX_I2C, __func__, s->address);
+ break;
+ }
+}
+
+static const MemoryRegionOps imx_i2c_ops = {
+ .read = imx_i2c_read,
+ .write = imx_i2c_write,
+ .valid.min_access_size = 1,
+ .valid.max_access_size = 2,
+ .endianness = DEVICE_NATIVE_ENDIAN,
+};
+
+static const VMStateDescription imx_i2c_vmstate = {
+ .name = TYPE_IMX_I2C,
+ .version_id = 1,
+ .minimum_version_id = 1,
+ .fields = (VMStateField[]) {
+ VMSTATE_UINT16(address, IMXI2CState),
+ VMSTATE_UINT16(iadr, IMXI2CState),
+ VMSTATE_UINT16(ifdr, IMXI2CState),
+ VMSTATE_UINT16(i2cr, IMXI2CState),
+ VMSTATE_UINT16(i2sr, IMXI2CState),
+ VMSTATE_UINT16(i2dr_read, IMXI2CState),
+ VMSTATE_UINT16(i2dr_write, IMXI2CState),
+ VMSTATE_END_OF_LIST()
+ }
+};
+
+static void imx_i2c_realize(DeviceState *dev, Error **errp)
+{
+ IMXI2CState *s = IMX_I2C(dev);
+
+ memory_region_init_io(&s->iomem, OBJECT(s), &imx_i2c_ops, s, TYPE_IMX_I2C,
+ IMX_I2C_MEM_SIZE);
+ sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->iomem);
+ sysbus_init_irq(SYS_BUS_DEVICE(dev), &s->irq);
+ s->bus = i2c_init_bus(DEVICE(dev), "i2c");
+}
+
+static void imx_i2c_class_init(ObjectClass *klass, void *data)
+{
+ DeviceClass *dc = DEVICE_CLASS(klass);
+
+ dc->vmsd = &imx_i2c_vmstate;
+ dc->reset = imx_i2c_reset;
+ dc->realize = imx_i2c_realize;
+}
+
+static const TypeInfo imx_i2c_type_info = {
+ .name = TYPE_IMX_I2C,
+ .parent = TYPE_SYS_BUS_DEVICE,
+ .instance_size = sizeof(IMXI2CState),
+ .class_init = imx_i2c_class_init,
+};
+
+static void imx_i2c_register_types(void)
+{
+ type_register_static(&imx_i2c_type_info);
+}
+
+type_init(imx_i2c_register_types)
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