On Sun, Dec 7, 2025 at 11:49 PM Kane Chen via <[email protected]> wrote:
>
> From: Kane-Chen-AS <[email protected]>
>
> Connect the I2C controller to the AST1700 model by mapping its MMIO
> region and wiring its interrupt line.
>
> This patch also adds a bus_label property to distinguish I2C buses on
> the BMC from those on external boards. This prevents user-specified
> I2C devices from being attached to the wrong bus when provided via CLI.
>
> Signed-off-by: Kane-Chen-AS <[email protected]>
> ---
> include/hw/arm/aspeed_ast1700.h | 2 ++
> include/hw/arm/aspeed_soc.h | 2 ++
> include/hw/i2c/aspeed_i2c.h | 1 +
> hw/arm/aspeed_ast1700.c | 18 ++++++++++++
> hw/arm/aspeed_ast27x0.c | 49 ++++++++++++++++++++++++++++++---
> hw/i2c/aspeed_i2c.c | 19 +++++++++++--
> 6 files changed, 85 insertions(+), 6 deletions(-)
>
> diff --git a/include/hw/arm/aspeed_ast1700.h b/include/hw/arm/aspeed_ast1700.h
> index 7ea6ff4c1a..d4b7abee7d 100644
> --- a/include/hw/arm/aspeed_ast1700.h
> +++ b/include/hw/arm/aspeed_ast1700.h
> @@ -12,6 +12,7 @@
> #include "hw/misc/aspeed_scu.h"
> #include "hw/adc/aspeed_adc.h"
> #include "hw/gpio/aspeed_gpio.h"
> +#include "hw/i2c/aspeed_i2c.h"
> #include "hw/misc/aspeed_ltpi.h"
> #include "hw/ssi/aspeed_smc.h"
> #include "hw/char/serial-mm.h"
> @@ -34,6 +35,7 @@ struct AspeedAST1700SoCState {
> AspeedADCState adc;
> AspeedSCUState scu;
> AspeedGPIOState gpio;
> + AspeedI2CState i2c;
> };
>
> #endif /* ASPEED_AST1700_H */
> diff --git a/include/hw/arm/aspeed_soc.h b/include/hw/arm/aspeed_soc.h
> index cebd8c21c8..602ce3924d 100644
> --- a/include/hw/arm/aspeed_soc.h
> +++ b/include/hw/arm/aspeed_soc.h
> @@ -290,6 +290,8 @@ enum {
> ASPEED_DEV_LTPI_CTRL2,
> ASPEED_DEV_LTPI_IO0,
> ASPEED_DEV_LTPI_IO1,
> + ASPEED_DEV_IOEXP0_I2C,
> + ASPEED_DEV_IOEXP1_I2C,
> ASPEED_DEV_IOEXP0_INTCIO,
> ASPEED_DEV_IOEXP1_INTCIO,
> };
> diff --git a/include/hw/i2c/aspeed_i2c.h b/include/hw/i2c/aspeed_i2c.h
> index 2daacc10ce..babbad5ed9 100644
> --- a/include/hw/i2c/aspeed_i2c.h
> +++ b/include/hw/i2c/aspeed_i2c.h
> @@ -269,6 +269,7 @@ struct AspeedI2CState {
> uint32_t intr_status;
> uint32_t ctrl_global;
> uint32_t new_clk_divider;
> + char *bus_label;
> MemoryRegion pool_iomem;
> uint8_t share_pool[ASPEED_I2C_SHARE_POOL_SIZE];
>
> diff --git a/hw/arm/aspeed_ast1700.c b/hw/arm/aspeed_ast1700.c
> index 1cb3cc4f7c..bd677727f5 100644
> --- a/hw/arm/aspeed_ast1700.c
> +++ b/hw/arm/aspeed_ast1700.c
> @@ -22,6 +22,7 @@ enum {
> ASPEED_AST1700_DEV_ADC,
> ASPEED_AST1700_DEV_SCU,
> ASPEED_AST1700_DEV_GPIO,
> + ASPEED_AST1700_DEV_I2C,
> ASPEED_AST1700_DEV_UART12,
> ASPEED_AST1700_DEV_LTPI_CTRL,
> ASPEED_AST1700_DEV_SPI0_MEM,
> @@ -33,6 +34,7 @@ static const hwaddr aspeed_ast1700_io_memmap[] = {
> [ASPEED_AST1700_DEV_ADC] = 0x00C00000,
> [ASPEED_AST1700_DEV_SCU] = 0x00C02000,
> [ASPEED_AST1700_DEV_GPIO] = 0x00C0B000,
> + [ASPEED_AST1700_DEV_I2C] = 0x00C0F000,
> [ASPEED_AST1700_DEV_UART12] = 0x00C33B00,
> [ASPEED_AST1700_DEV_LTPI_CTRL] = 0x00C34000,
> [ASPEED_AST1700_DEV_SPI0_MEM] = 0x04000000,
> @@ -108,6 +110,18 @@ static void aspeed_ast1700_realize(DeviceState *dev,
> Error **errp)
> aspeed_ast1700_io_memmap[ASPEED_AST1700_DEV_GPIO],
> sysbus_mmio_get_region(SYS_BUS_DEVICE(&s->gpio), 0));
>
> + /* I2C */
> + snprintf(dev_name, sizeof(dev_name), "ioexp%d", s->board_idx);
> + qdev_prop_set_string(DEVICE(&s->i2c), "bus-label", dev_name);
> + object_property_set_link(OBJECT(&s->i2c), "dram",
> + OBJECT(&s->iomem), errp);
> + if (!sysbus_realize(SYS_BUS_DEVICE(&s->i2c), errp)) {
> + return;
> + }
> + memory_region_add_subregion(&s->iomem,
> + aspeed_ast1700_io_memmap[ASPEED_AST1700_DEV_I2C],
> + sysbus_mmio_get_region(SYS_BUS_DEVICE(&s->i2c), 0));
> +
> /* LTPI controller */
> if (!sysbus_realize(SYS_BUS_DEVICE(&s->ltpi), errp)) {
> return;
> @@ -141,6 +155,10 @@ static void aspeed_ast1700_instance_init(Object *obj)
> object_initialize_child(obj, "ioexp-gpio[*]", &s->gpio,
> "aspeed.gpio-ast2700");
>
> + /* I2C */
> + object_initialize_child(obj, "ioexp-i2c[*]", &s->i2c,
> + "aspeed.i2c-ast2700");
> +
> /* LTPI controller */
> object_initialize_child(obj, "ltpi-ctrl",
> &s->ltpi, TYPE_ASPEED_LTPI);
> diff --git a/hw/arm/aspeed_ast27x0.c b/hw/arm/aspeed_ast27x0.c
> index 402799416f..7433d365a3 100644
> --- a/hw/arm/aspeed_ast27x0.c
> +++ b/hw/arm/aspeed_ast27x0.c
> @@ -205,6 +205,8 @@ static const int aspeed_soc_ast2700a1_irqmap[] = {
> [ASPEED_DEV_ETH3] = 196,
> [ASPEED_DEV_PECI] = 197,
> [ASPEED_DEV_SDHCI] = 197,
> + [ASPEED_DEV_IOEXP0_I2C] = 198,
> + [ASPEED_DEV_IOEXP1_I2C] = 200,
> };
>
> /* GICINT 128 */
> @@ -267,6 +269,18 @@ static const int ast2700_gic133_gic197_intcmap[] = {
> [ASPEED_DEV_PECI] = 4,
> };
>
> +/* Primary AST1700 Interrupts */
> +/* A1: GICINT 198 */
> +static const int ast2700_gic198_intcmap[] = {
> + [ASPEED_DEV_IOEXP0_I2C] = 0, /* 0 - 15 */
> +};
> +
> +/* Secondary AST1700 Interrupts */
> +/* A1: GINTC 200 */
> +static const int ast2700_gic200_intcmap[] = {
> + [ASPEED_DEV_IOEXP1_I2C] = 0, /* 0 - 15 */
> +};
> +
> /* GICINT 128 ~ 136 */
> /* GICINT 192 ~ 201 */
> struct gic_intc_irq_info {
> @@ -283,9 +297,9 @@ static const struct gic_intc_irq_info
> ast2700_gic_intcmap[] = {
> {195, 1, 3, ast2700_gic131_gic195_intcmap},
> {196, 1, 4, ast2700_gic132_gic196_intcmap},
> {197, 1, 5, ast2700_gic133_gic197_intcmap},
> - {198, 1, 6, NULL},
> + {198, 2, 0, ast2700_gic198_intcmap},
> {199, 1, 7, NULL},
> - {200, 1, 8, NULL},
> + {200, 3, 0, ast2700_gic200_intcmap},
> {201, 1, 9, NULL},
> {128, 0, 1, ast2700_gic128_gic192_intcmap},
> {129, 0, 2, NULL},
> @@ -333,8 +347,13 @@ static qemu_irq
> aspeed_soc_ast2700_get_irq_index(AspeedSoCState *s, int dev,
> assert(ast2700_gic_intcmap[i].ptr);
> or_idx = ast2700_gic_intcmap[i].orgate_idx;
> idx = ast2700_gic_intcmap[i].intc_idx;
> - return qdev_get_gpio_in(DEVICE(&a->intc[idx].orgates[or_idx]),
> - ast2700_gic_intcmap[i].ptr[dev] + index);
> + if (idx < ASPEED_INTC_NUM) {
> + return
> qdev_get_gpio_in(DEVICE(&a->intc[idx].orgates[or_idx]),
> + ast2700_gic_intcmap[i].ptr[dev] +
> index);
> + } else {
> + return qdev_get_gpio_in(DEVICE(&a->intcioexp[idx -
> ASPEED_INTC_NUM].orgates[or_idx]),
> + ast2700_gic_intcmap[i].ptr[dev] +
> index);
> + }
checkpatch.pl complains about some of these lines being 80+
characters, and errors on the last return being over 90 characters.
> }
> }
>
> @@ -1098,6 +1117,8 @@ static void aspeed_soc_ast2700_realize(DeviceState
> *dev, Error **errp)
>
> /* IO Expander */
> for (i = 0; i < sc->ioexp_num; i++) {
> + AspeedI2CClass *i2c_ctl;
> +
> qdev_prop_set_uint8(DEVICE(&s->ioexp[i]), "board-idx", i);
> if (!sysbus_realize(SYS_BUS_DEVICE(&s->ioexp[i]), errp)) {
> return;
> @@ -1128,6 +1149,26 @@ static void aspeed_soc_ast2700_realize(DeviceState
> *dev, Error **errp)
> sysbus_connect_irq(SYS_BUS_DEVICE(&s->ioexp[i].gpio), 0,
> aspeed_soc_ast2700_get_irq(s, ASPEED_DEV_GPIO));
>
> + /* I2C */
> + i2c_ctl = ASPEED_I2C_GET_CLASS(&s->ioexp[i].i2c);
> + for (int j = 0; j < i2c_ctl->num_busses; j++) {
> + /*
> + * For I2C on AST1700:
> + * I2C bus interrupts are connected to the OR gate from bit 0 to
> bit
> + * 15, and the OR gate output pin is connected to the input pin
> of
> + * GICINT192 of IO expander Interrupt controller (INTC2/3). Then,
> + * the output pin is connected to the INTC (CPU Die) input pin,
> and
> + * its output pin is connected to the GIC.
> + *
> + * I2C bus 0 is connected to the OR gate at bit 0.
> + * I2C bus 15 is connected to the OR gate at bit 15.
> + */
> + irq = aspeed_soc_ast2700_get_irq_index(s,
> + ASPEED_DEV_IOEXP0_I2C + i,
> + j);
> + sysbus_connect_irq(SYS_BUS_DEVICE(&s->ioexp[i].i2c.busses[j]),
> + 0, irq);
> + }
> }
>
> aspeed_mmio_map_unimplemented(s->memory, SYS_BUS_DEVICE(&s->dpmcu),
> diff --git a/hw/i2c/aspeed_i2c.c b/hw/i2c/aspeed_i2c.c
> index 83fb906bdc..ca84068bb4 100644
> --- a/hw/i2c/aspeed_i2c.c
> +++ b/hw/i2c/aspeed_i2c.c
> @@ -1261,6 +1261,7 @@ static void aspeed_i2c_realize(DeviceState *dev, Error
> **errp)
> static const Property aspeed_i2c_properties[] = {
> DEFINE_PROP_LINK("dram", AspeedI2CState, dram_mr,
> TYPE_MEMORY_REGION, MemoryRegion *),
> + DEFINE_PROP_STRING("bus-label", AspeedI2CState, bus_label),
> };
>
> static void aspeed_i2c_class_init(ObjectClass *klass, const void *data)
> @@ -1421,14 +1422,28 @@ static void aspeed_i2c_bus_realize(DeviceState *dev,
> Error **errp)
> {
> AspeedI2CBus *s = ASPEED_I2C_BUS(dev);
> AspeedI2CClass *aic;
> - g_autofree char *name = g_strdup_printf(TYPE_ASPEED_I2C_BUS ".%d",
> s->id);
> - g_autofree char *pool_name = g_strdup_printf("%s.pool", name);
> + g_autofree char *name = NULL;
> + g_autofree char *pool_name = NULL;
>
> if (!s->controller) {
> error_setg(errp, TYPE_ASPEED_I2C_BUS ": 'controller' link not set");
> return;
> }
>
> + /*
> + * I2C bus naming:
> + * - Empty bus_label -> BMC internal controller, use default name.
> + * - Non-empty bus_label -> external/addon controller, prefix with
> label
> + * to avoid conflicts and show bus origin.
> + */
> + if (!s->controller->bus_label || (strlen(s->controller->bus_label) ==
> 0)) {
> + name = g_strdup_printf(TYPE_ASPEED_I2C_BUS ".%d", s->id);
> + } else {
> + name = g_strdup_printf("aspeed.%s.i2c.bus.%d",
> + s->controller->bus_label, s->id);
> + }
> + pool_name = g_strdup_printf("%s.pool", name);
> +
> aic = ASPEED_I2C_GET_CLASS(s->controller);
>
> sysbus_init_irq(SYS_BUS_DEVICE(dev), &s->irq);
> --
> 2.43.0
>
>
