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qemu-e2k/hw/i2c/aspeed_i2c.c
Guenter Roeck bb626e5b43 aspeed/i2c: Fix receive done interrupt handling 
The AST2500 datasheet says:

I2CD10 Interrupt Status Register
       bit 2 Receive Done Interrupt status
             S/W needs to clear this status bit to allow next data receiving

The Rx interrupt done interrupt status bit needs to be cleared
explicitly before the next byte can be received, and must therefore
not be auto-cleared. Also, receiving the next byte must be delayed
until the bit has been cleared.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-id: 20180914063506.20815-4-clg@kaod.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2018-09-25 14:14:07 +01:00

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/*
* ARM Aspeed I2C controller
*
* Copyright (C) 2016 IBM Corp.
*
* 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/osdep.h"
#include "hw/sysbus.h"
#include "qemu/log.h"
#include "hw/i2c/aspeed_i2c.h"
/* I2C Global Register */
#define I2C_CTRL_STATUS 0x00 /* Device Interrupt Status */
#define I2C_CTRL_ASSIGN 0x08 /* Device Interrupt Target
Assignment */
/* I2C Device (Bus) Register */
#define I2CD_FUN_CTRL_REG 0x00 /* I2CD Function Control */
#define I2CD_BUFF_SEL_MASK (0x7 << 20)
#define I2CD_BUFF_SEL(x) (x << 20)
#define I2CD_M_SDA_LOCK_EN (0x1 << 16)
#define I2CD_MULTI_MASTER_DIS (0x1 << 15)
#define I2CD_M_SCL_DRIVE_EN (0x1 << 14)
#define I2CD_MSB_STS (0x1 << 9)
#define I2CD_SDA_DRIVE_1T_EN (0x1 << 8)
#define I2CD_M_SDA_DRIVE_1T_EN (0x1 << 7)
#define I2CD_M_HIGH_SPEED_EN (0x1 << 6)
#define I2CD_DEF_ADDR_EN (0x1 << 5)
#define I2CD_DEF_ALERT_EN (0x1 << 4)
#define I2CD_DEF_ARP_EN (0x1 << 3)
#define I2CD_DEF_GCALL_EN (0x1 << 2)
#define I2CD_SLAVE_EN (0x1 << 1)
#define I2CD_MASTER_EN (0x1)
#define I2CD_AC_TIMING_REG1 0x04 /* Clock and AC Timing Control #1 */
#define I2CD_AC_TIMING_REG2 0x08 /* Clock and AC Timing Control #1 */
#define I2CD_INTR_CTRL_REG 0x0c /* I2CD Interrupt Control */
#define I2CD_INTR_STS_REG 0x10 /* I2CD Interrupt Status */
#define I2CD_INTR_SLAVE_ADDR_MATCH (0x1 << 31) /* 0: addr1 1: addr2 */
#define I2CD_INTR_SLAVE_ADDR_RX_PENDING (0x1 << 30)
/* bits[19-16] Reserved */
/* All bits below are cleared by writing 1 */
#define I2CD_INTR_SLAVE_INACTIVE_TIMEOUT (0x1 << 15)
#define I2CD_INTR_SDA_DL_TIMEOUT (0x1 << 14)
#define I2CD_INTR_BUS_RECOVER_DONE (0x1 << 13)
#define I2CD_INTR_SMBUS_ALERT (0x1 << 12) /* Bus [0-3] only */
#define I2CD_INTR_SMBUS_ARP_ADDR (0x1 << 11) /* Removed */
#define I2CD_INTR_SMBUS_DEV_ALERT_ADDR (0x1 << 10) /* Removed */
#define I2CD_INTR_SMBUS_DEF_ADDR (0x1 << 9) /* Removed */
#define I2CD_INTR_GCALL_ADDR (0x1 << 8) /* Removed */
#define I2CD_INTR_SLAVE_ADDR_RX_MATCH (0x1 << 7) /* use RX_DONE */
#define I2CD_INTR_SCL_TIMEOUT (0x1 << 6)
#define I2CD_INTR_ABNORMAL (0x1 << 5)
#define I2CD_INTR_NORMAL_STOP (0x1 << 4)
#define I2CD_INTR_ARBIT_LOSS (0x1 << 3)
#define I2CD_INTR_RX_DONE (0x1 << 2)
#define I2CD_INTR_TX_NAK (0x1 << 1)
#define I2CD_INTR_TX_ACK (0x1 << 0)
#define I2CD_CMD_REG 0x14 /* I2CD Command/Status */
#define I2CD_SDA_OE (0x1 << 28)
#define I2CD_SDA_O (0x1 << 27)
#define I2CD_SCL_OE (0x1 << 26)
#define I2CD_SCL_O (0x1 << 25)
#define I2CD_TX_TIMING (0x1 << 24)
#define I2CD_TX_STATUS (0x1 << 23)
#define I2CD_TX_STATE_SHIFT 19 /* Tx State Machine */
#define I2CD_TX_STATE_MASK 0xf
#define I2CD_IDLE 0x0
#define I2CD_MACTIVE 0x8
#define I2CD_MSTART 0x9
#define I2CD_MSTARTR 0xa
#define I2CD_MSTOP 0xb
#define I2CD_MTXD 0xc
#define I2CD_MRXACK 0xd
#define I2CD_MRXD 0xe
#define I2CD_MTXACK 0xf
#define I2CD_SWAIT 0x1
#define I2CD_SRXD 0x4
#define I2CD_STXACK 0x5
#define I2CD_STXD 0x6
#define I2CD_SRXACK 0x7
#define I2CD_RECOVER 0x3
#define I2CD_SCL_LINE_STS (0x1 << 18)
#define I2CD_SDA_LINE_STS (0x1 << 17)
#define I2CD_BUS_BUSY_STS (0x1 << 16)
#define I2CD_SDA_OE_OUT_DIR (0x1 << 15)
#define I2CD_SDA_O_OUT_DIR (0x1 << 14)
#define I2CD_SCL_OE_OUT_DIR (0x1 << 13)
#define I2CD_SCL_O_OUT_DIR (0x1 << 12)
#define I2CD_BUS_RECOVER_CMD_EN (0x1 << 11)
#define I2CD_S_ALT_EN (0x1 << 10)
#define I2CD_RX_DMA_ENABLE (0x1 << 9)
#define I2CD_TX_DMA_ENABLE (0x1 << 8)
/* Command Bit */
#define I2CD_M_STOP_CMD (0x1 << 5)
#define I2CD_M_S_RX_CMD_LAST (0x1 << 4)
#define I2CD_M_RX_CMD (0x1 << 3)
#define I2CD_S_TX_CMD (0x1 << 2)
#define I2CD_M_TX_CMD (0x1 << 1)
#define I2CD_M_START_CMD (0x1)
#define I2CD_DEV_ADDR_REG 0x18 /* Slave Device Address */
#define I2CD_BUF_CTRL_REG 0x1c /* Pool Buffer Control */
#define I2CD_BYTE_BUF_REG 0x20 /* Transmit/Receive Byte Buffer */
#define I2CD_BYTE_BUF_TX_SHIFT 0
#define I2CD_BYTE_BUF_TX_MASK 0xff
#define I2CD_BYTE_BUF_RX_SHIFT 8
#define I2CD_BYTE_BUF_RX_MASK 0xff
static inline bool aspeed_i2c_bus_is_master(AspeedI2CBus *bus)
{
return bus->ctrl & I2CD_MASTER_EN;
}
static inline bool aspeed_i2c_bus_is_enabled(AspeedI2CBus *bus)
{
return bus->ctrl & (I2CD_MASTER_EN | I2CD_SLAVE_EN);
}
static inline void aspeed_i2c_bus_raise_interrupt(AspeedI2CBus *bus)
{
bus->intr_status &= bus->intr_ctrl;
if (bus->intr_status) {
bus->controller->intr_status |= 1 << bus->id;
qemu_irq_raise(bus->controller->irq);
}
}
static uint64_t aspeed_i2c_bus_read(void *opaque, hwaddr offset,
unsigned size)
{
AspeedI2CBus *bus = opaque;
switch (offset) {
case I2CD_FUN_CTRL_REG:
return bus->ctrl;
case I2CD_AC_TIMING_REG1:
return bus->timing[0];
case I2CD_AC_TIMING_REG2:
return bus->timing[1];
case I2CD_INTR_CTRL_REG:
return bus->intr_ctrl;
case I2CD_INTR_STS_REG:
return bus->intr_status;
case I2CD_BYTE_BUF_REG:
return bus->buf;
case I2CD_CMD_REG:
return bus->cmd | (i2c_bus_busy(bus->bus) << 16);
default:
qemu_log_mask(LOG_GUEST_ERROR,
"%s: Bad offset 0x%" HWADDR_PRIx "\n", __func__, offset);
return -1;
}
}
static void aspeed_i2c_set_state(AspeedI2CBus *bus, uint8_t state)
{
bus->cmd &= ~(I2CD_TX_STATE_MASK << I2CD_TX_STATE_SHIFT);
bus->cmd |= (state & I2CD_TX_STATE_MASK) << I2CD_TX_STATE_SHIFT;
}
static uint8_t aspeed_i2c_get_state(AspeedI2CBus *bus)
{
return (bus->cmd >> I2CD_TX_STATE_SHIFT) & I2CD_TX_STATE_MASK;
}
static void aspeed_i2c_handle_rx_cmd(AspeedI2CBus *bus)
{
int ret;
aspeed_i2c_set_state(bus, I2CD_MRXD);
ret = i2c_recv(bus->bus);
if (ret < 0) {
qemu_log_mask(LOG_GUEST_ERROR, "%s: read failed\n", __func__);
ret = 0xff;
} else {
bus->intr_status |= I2CD_INTR_RX_DONE;
}
bus->buf = (ret & I2CD_BYTE_BUF_RX_MASK) << I2CD_BYTE_BUF_RX_SHIFT;
if (bus->cmd & I2CD_M_S_RX_CMD_LAST) {
i2c_nack(bus->bus);
}
bus->cmd &= ~(I2CD_M_RX_CMD | I2CD_M_S_RX_CMD_LAST);
aspeed_i2c_set_state(bus, I2CD_MACTIVE);
}
/*
* The state machine needs some refinement. It is only used to track
* invalid STOP commands for the moment.
*/
static void aspeed_i2c_bus_handle_cmd(AspeedI2CBus *bus, uint64_t value)
{
bus->cmd &= ~0xFFFF;
bus->cmd |= value & 0xFFFF;
if (bus->cmd & I2CD_M_START_CMD) {
uint8_t state = aspeed_i2c_get_state(bus) & I2CD_MACTIVE ?
I2CD_MSTARTR : I2CD_MSTART;
aspeed_i2c_set_state(bus, state);
if (i2c_start_transfer(bus->bus, extract32(bus->buf, 1, 7),
extract32(bus->buf, 0, 1))) {
bus->intr_status |= I2CD_INTR_TX_NAK;
} else {
bus->intr_status |= I2CD_INTR_TX_ACK;
}
/* START command is also a TX command, as the slave address is
* sent on the bus */
bus->cmd &= ~(I2CD_M_START_CMD | I2CD_M_TX_CMD);
/* No slave found */
if (!i2c_bus_busy(bus->bus)) {
return;
}
aspeed_i2c_set_state(bus, I2CD_MACTIVE);
}
if (bus->cmd & I2CD_M_TX_CMD) {
aspeed_i2c_set_state(bus, I2CD_MTXD);
if (i2c_send(bus->bus, bus->buf)) {
bus->intr_status |= (I2CD_INTR_TX_NAK);
i2c_end_transfer(bus->bus);
} else {
bus->intr_status |= I2CD_INTR_TX_ACK;
}
bus->cmd &= ~I2CD_M_TX_CMD;
aspeed_i2c_set_state(bus, I2CD_MACTIVE);
}
if ((bus->cmd & (I2CD_M_RX_CMD | I2CD_M_S_RX_CMD_LAST)) &&
!(bus->intr_status & I2CD_INTR_RX_DONE)) {
aspeed_i2c_handle_rx_cmd(bus);
}
if (bus->cmd & I2CD_M_STOP_CMD) {
if (!(aspeed_i2c_get_state(bus) & I2CD_MACTIVE)) {
qemu_log_mask(LOG_GUEST_ERROR, "%s: abnormal stop\n", __func__);
bus->intr_status |= I2CD_INTR_ABNORMAL;
} else {
aspeed_i2c_set_state(bus, I2CD_MSTOP);
i2c_end_transfer(bus->bus);
bus->intr_status |= I2CD_INTR_NORMAL_STOP;
}
bus->cmd &= ~I2CD_M_STOP_CMD;
aspeed_i2c_set_state(bus, I2CD_IDLE);
}
}
static void aspeed_i2c_bus_write(void *opaque, hwaddr offset,
uint64_t value, unsigned size)
{
AspeedI2CBus *bus = opaque;
bool handle_rx;
switch (offset) {
case I2CD_FUN_CTRL_REG:
if (value & I2CD_SLAVE_EN) {
qemu_log_mask(LOG_UNIMP, "%s: slave mode not implemented\n",
__func__);
break;
}
bus->ctrl = value & 0x0071C3FF;
break;
case I2CD_AC_TIMING_REG1:
bus->timing[0] = value & 0xFFFFF0F;
break;
case I2CD_AC_TIMING_REG2:
bus->timing[1] = value & 0x7;
break;
case I2CD_INTR_CTRL_REG:
bus->intr_ctrl = value & 0x7FFF;
break;
case I2CD_INTR_STS_REG:
handle_rx = (bus->intr_status & I2CD_INTR_RX_DONE) &&
(value & I2CD_INTR_RX_DONE);
bus->intr_status &= ~(value & 0x7FFF);
if (!bus->intr_status) {
bus->controller->intr_status &= ~(1 << bus->id);
qemu_irq_lower(bus->controller->irq);
}
if (handle_rx && (bus->cmd & (I2CD_M_RX_CMD | I2CD_M_S_RX_CMD_LAST))) {
aspeed_i2c_handle_rx_cmd(bus);
aspeed_i2c_bus_raise_interrupt(bus);
}
break;
case I2CD_DEV_ADDR_REG:
qemu_log_mask(LOG_UNIMP, "%s: slave mode not implemented\n",
__func__);
break;
case I2CD_BYTE_BUF_REG:
bus->buf = (value & I2CD_BYTE_BUF_TX_MASK) << I2CD_BYTE_BUF_TX_SHIFT;
break;
case I2CD_CMD_REG:
if (!aspeed_i2c_bus_is_enabled(bus)) {
break;
}
if (!aspeed_i2c_bus_is_master(bus)) {
qemu_log_mask(LOG_UNIMP, "%s: slave mode not implemented\n",
__func__);
break;
}
aspeed_i2c_bus_handle_cmd(bus, value);
aspeed_i2c_bus_raise_interrupt(bus);
break;
default:
qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset 0x%" HWADDR_PRIx "\n",
__func__, offset);
}
}
static uint64_t aspeed_i2c_ctrl_read(void *opaque, hwaddr offset,
unsigned size)
{
AspeedI2CState *s = opaque;
switch (offset) {
case I2C_CTRL_STATUS:
return s->intr_status;
default:
qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset 0x%" HWADDR_PRIx "\n",
__func__, offset);
break;
}
return -1;
}
static void aspeed_i2c_ctrl_write(void *opaque, hwaddr offset,
uint64_t value, unsigned size)
{
switch (offset) {
case I2C_CTRL_STATUS:
default:
qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset 0x%" HWADDR_PRIx "\n",
__func__, offset);
break;
}
}
static const MemoryRegionOps aspeed_i2c_bus_ops = {
.read = aspeed_i2c_bus_read,
.write = aspeed_i2c_bus_write,
.endianness = DEVICE_LITTLE_ENDIAN,
};
static const MemoryRegionOps aspeed_i2c_ctrl_ops = {
.read = aspeed_i2c_ctrl_read,
.write = aspeed_i2c_ctrl_write,
.endianness = DEVICE_LITTLE_ENDIAN,
};
static const VMStateDescription aspeed_i2c_bus_vmstate = {
.name = TYPE_ASPEED_I2C,
.version_id = 1,
.minimum_version_id = 1,
.fields = (VMStateField[]) {
VMSTATE_UINT8(id, AspeedI2CBus),
VMSTATE_UINT32(ctrl, AspeedI2CBus),
VMSTATE_UINT32_ARRAY(timing, AspeedI2CBus, 2),
VMSTATE_UINT32(intr_ctrl, AspeedI2CBus),
VMSTATE_UINT32(intr_status, AspeedI2CBus),
VMSTATE_UINT32(cmd, AspeedI2CBus),
VMSTATE_UINT32(buf, AspeedI2CBus),
VMSTATE_END_OF_LIST()
}
};
static const VMStateDescription aspeed_i2c_vmstate = {
.name = TYPE_ASPEED_I2C,
.version_id = 1,
.minimum_version_id = 1,
.fields = (VMStateField[]) {
VMSTATE_UINT32(intr_status, AspeedI2CState),
VMSTATE_STRUCT_ARRAY(busses, AspeedI2CState,
ASPEED_I2C_NR_BUSSES, 1, aspeed_i2c_bus_vmstate,
AspeedI2CBus),
VMSTATE_END_OF_LIST()
}
};
static void aspeed_i2c_reset(DeviceState *dev)
{
int i;
AspeedI2CState *s = ASPEED_I2C(dev);
s->intr_status = 0;
for (i = 0; i < ASPEED_I2C_NR_BUSSES; i++) {
s->busses[i].intr_ctrl = 0;
s->busses[i].intr_status = 0;
s->busses[i].cmd = 0;
s->busses[i].buf = 0;
i2c_end_transfer(s->busses[i].bus);
}
}
/*
* Address Definitions
*
* 0x000 ... 0x03F: Global Register
* 0x040 ... 0x07F: Device 1
* 0x080 ... 0x0BF: Device 2
* 0x0C0 ... 0x0FF: Device 3
* 0x100 ... 0x13F: Device 4
* 0x140 ... 0x17F: Device 5
* 0x180 ... 0x1BF: Device 6
* 0x1C0 ... 0x1FF: Device 7
* 0x200 ... 0x2FF: Buffer Pool (unused in linux driver)
* 0x300 ... 0x33F: Device 8
* 0x340 ... 0x37F: Device 9
* 0x380 ... 0x3BF: Device 10
* 0x3C0 ... 0x3FF: Device 11
* 0x400 ... 0x43F: Device 12
* 0x440 ... 0x47F: Device 13
* 0x480 ... 0x4BF: Device 14
* 0x800 ... 0xFFF: Buffer Pool (unused in linux driver)
*/
static void aspeed_i2c_realize(DeviceState *dev, Error **errp)
{
int i;
SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
AspeedI2CState *s = ASPEED_I2C(dev);
sysbus_init_irq(sbd, &s->irq);
memory_region_init_io(&s->iomem, OBJECT(s), &aspeed_i2c_ctrl_ops, s,
"aspeed.i2c", 0x1000);
sysbus_init_mmio(sbd, &s->iomem);
for (i = 0; i < ASPEED_I2C_NR_BUSSES; i++) {
char name[16];
int offset = i < 7 ? 1 : 5;
snprintf(name, sizeof(name), "aspeed.i2c.%d", i);
s->busses[i].controller = s;
s->busses[i].id = i;
s->busses[i].bus = i2c_init_bus(dev, name);
memory_region_init_io(&s->busses[i].mr, OBJECT(dev),
&aspeed_i2c_bus_ops, &s->busses[i], name, 0x40);
memory_region_add_subregion(&s->iomem, 0x40 * (i + offset),
&s->busses[i].mr);
}
}
static void aspeed_i2c_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
dc->vmsd = &aspeed_i2c_vmstate;
dc->reset = aspeed_i2c_reset;
dc->realize = aspeed_i2c_realize;
dc->desc = "Aspeed I2C Controller";
}
static const TypeInfo aspeed_i2c_info = {
.name = TYPE_ASPEED_I2C,
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(AspeedI2CState),
.class_init = aspeed_i2c_class_init,
};
static void aspeed_i2c_register_types(void)
{
type_register_static(&aspeed_i2c_info);
}
type_init(aspeed_i2c_register_types)
I2CBus *aspeed_i2c_get_bus(DeviceState *dev, int busnr)
{
AspeedI2CState *s = ASPEED_I2C(dev);
I2CBus *bus = NULL;
if (busnr >= 0 && busnr < ASPEED_I2C_NR_BUSSES) {
bus = s->busses[busnr].bus;
}
return bus;
}
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