Adds Atlantis Reset Controller and auxiliary device definitions for
reset to share same regmap interface as clock controller.
This version of the reset controller driver covers resets from the RCPU
syscon.
Signed-off-by: Anirudh Srinivasan <asrinivasan@oss.tenstorrent.com>
---
MAINTAINERS | 2 +
drivers/reset/Kconfig | 11 ++
drivers/reset/Makefile | 1 +
drivers/reset/reset-tenstorrent-atlantis.c | 158 +++++++++++++++++++++++++++++
include/soc/tenstorrent/atlantis-syscon.h | 26 +++++
5 files changed, 198 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index 19a98b1fa456..cf7c8e2153dc 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -22537,7 +22537,9 @@ T: git https://github.com/tenstorrent/linux.git
F: Documentation/devicetree/bindings/riscv/tenstorrent.yaml
F: Documentation/devicetree/bindings/soc/tenstorrent/tenstorrent,atlantis-syscon.yaml
F: arch/riscv/boot/dts/tenstorrent/
+F: drivers/reset/reset-tenstorrent-atlantis.c
F: include/dt-bindings/clock/tenstorrent,atlantis-syscon.h
+F: include/soc/tenstorrent/
RISC-V THEAD SoC SUPPORT
M: Drew Fustini <fustini@kernel.org>
diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
index 6e5d6deffa7d..cade77717492 100644
--- a/drivers/reset/Kconfig
+++ b/drivers/reset/Kconfig
@@ -324,6 +324,17 @@ config RESET_SUNXI
help
This enables the reset driver for Allwinner SoCs.
+config RESET_TENSTORRENT_ATLANTIS
+ tristate "Tenstorrent atlantis reset driver"
+ depends on ARCH_TENSTORRENT || COMPILE_TEST
+ select AUXILIARY_BUS
+ default ARCH_TENSTORRENT
+ help
+ This enables the driver for the reset controller
+ present in the Tenstorrent Atlantis SoC.
+ Enable this option to be able to use hardware
+ resets on Atalantis based systems.
+
config RESET_TH1520
tristate "T-HEAD TH1520 reset controller"
depends on ARCH_THEAD || COMPILE_TEST
diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
index 9c3e484dfd81..a31959da0a88 100644
--- a/drivers/reset/Makefile
+++ b/drivers/reset/Makefile
@@ -41,6 +41,7 @@ obj-$(CONFIG_RESET_SOCFPGA) += reset-socfpga.o
obj-$(CONFIG_RESET_SPACEMIT) += reset-spacemit.o
obj-$(CONFIG_RESET_SUNPLUS) += reset-sunplus.o
obj-$(CONFIG_RESET_SUNXI) += reset-sunxi.o
+obj-$(CONFIG_RESET_TENSTORRENT_ATLANTIS) += reset-tenstorrent-atlantis.o
obj-$(CONFIG_RESET_TH1520) += reset-th1520.o
obj-$(CONFIG_RESET_TI_SCI) += reset-ti-sci.o
obj-$(CONFIG_RESET_TI_SYSCON) += reset-ti-syscon.o
diff --git a/drivers/reset/reset-tenstorrent-atlantis.c b/drivers/reset/reset-tenstorrent-atlantis.c
new file mode 100644
index 000000000000..2e7f09409f79
--- /dev/null
+++ b/drivers/reset/reset-tenstorrent-atlantis.c
@@ -0,0 +1,158 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2026 Tenstorrent
+ */
+
+#include <dt-bindings/clock/tenstorrent,atlantis-syscon.h>
+#include <linux/auxiliary_bus.h>
+#include <linux/reset-controller.h>
+#include <linux/regmap.h>
+#include <soc/tenstorrent/atlantis-syscon.h>
+
+struct atlantis_reset_data {
+ u8 bit;
+ u16 reg;
+ bool active_low;
+};
+
+struct atlantis_reset_controller_data {
+ const struct atlantis_reset_data *reset_data;
+ size_t count;
+};
+
+struct atlantis_reset_controller {
+ struct reset_controller_dev rcdev;
+ const struct atlantis_reset_controller_data *data;
+ struct regmap *regmap;
+};
+
+#define to_atlantis_reset_controller(_rcdev) \
+ container_of((_rcdev), struct atlantis_reset_controller, rcdev)
+
+#define RESET_DATA(_reg, _bit, _active_low) \
+ { \
+ .bit = _bit, .reg = _reg, .active_low = _active_low, \
+ }
+
+static const struct atlantis_reset_data atlantis_rcpu_resets[] = {
+ [RST_SMNDMA0] = RESET_DATA(RCPU_BLK_RST_REG, 0, true),
+ [RST_SMNDMA1] = RESET_DATA(RCPU_BLK_RST_REG, 1, true),
+ [RST_WDT0] = RESET_DATA(RCPU_BLK_RST_REG, 2, true),
+ [RST_WDT1] = RESET_DATA(RCPU_BLK_RST_REG, 3, true),
+ [RST_TMR] = RESET_DATA(RCPU_BLK_RST_REG, 4, true),
+ [RST_PVTC] = RESET_DATA(RCPU_BLK_RST_REG, 12, true),
+ [RST_PMU] = RESET_DATA(RCPU_BLK_RST_REG, 13, true),
+ [RST_MAILBOX] = RESET_DATA(RCPU_BLK_RST_REG, 14, true),
+ [RST_SPACC] = RESET_DATA(RCPU_BLK_RST_REG, 26, true),
+ [RST_OTP] = RESET_DATA(RCPU_BLK_RST_REG, 28, true),
+ [RST_TRNG] = RESET_DATA(RCPU_BLK_RST_REG, 29, true),
+ [RST_CRC] = RESET_DATA(RCPU_BLK_RST_REG, 30, true),
+ [RST_QSPI] = RESET_DATA(LSIO_BLK_RST_REG, 0, true),
+ [RST_I2C0] = RESET_DATA(LSIO_BLK_RST_REG, 1, true),
+ [RST_I2C1] = RESET_DATA(LSIO_BLK_RST_REG, 2, true),
+ [RST_I2C2] = RESET_DATA(LSIO_BLK_RST_REG, 3, true),
+ [RST_I2C3] = RESET_DATA(LSIO_BLK_RST_REG, 4, true),
+ [RST_I2C4] = RESET_DATA(LSIO_BLK_RST_REG, 5, true),
+ [RST_UART0] = RESET_DATA(LSIO_BLK_RST_REG, 6, true),
+ [RST_UART1] = RESET_DATA(LSIO_BLK_RST_REG, 7, true),
+ [RST_UART2] = RESET_DATA(LSIO_BLK_RST_REG, 8, true),
+ [RST_UART3] = RESET_DATA(LSIO_BLK_RST_REG, 9, true),
+ [RST_UART4] = RESET_DATA(LSIO_BLK_RST_REG, 10, true),
+ [RST_SPI0] = RESET_DATA(LSIO_BLK_RST_REG, 11, true),
+ [RST_SPI1] = RESET_DATA(LSIO_BLK_RST_REG, 12, true),
+ [RST_SPI2] = RESET_DATA(LSIO_BLK_RST_REG, 13, true),
+ [RST_SPI3] = RESET_DATA(LSIO_BLK_RST_REG, 14, true),
+ [RST_GPIO] = RESET_DATA(LSIO_BLK_RST_REG, 15, true),
+ [RST_CAN0] = RESET_DATA(LSIO_BLK_RST_REG, 17, true),
+ [RST_CAN1] = RESET_DATA(LSIO_BLK_RST_REG, 18, true),
+ [RST_I2S0] = RESET_DATA(LSIO_BLK_RST_REG, 19, true),
+ [RST_I2S1] = RESET_DATA(LSIO_BLK_RST_REG, 20, true),
+
+};
+
+static const struct atlantis_reset_controller_data atlantis_rcpu_reset_data = {
+ .reset_data = atlantis_rcpu_resets,
+ .count = ARRAY_SIZE(atlantis_rcpu_resets),
+};
+
+static int atlantis_reset_update(struct reset_controller_dev *rcdev,
+ unsigned long id, bool assert)
+{
+ unsigned int val;
+ struct atlantis_reset_controller *rst =
+ to_atlantis_reset_controller(rcdev);
+ const struct atlantis_reset_data *data = &rst->data->reset_data[id];
+ unsigned int mask = BIT(data->bit);
+ struct regmap *regmap = rst->regmap;
+
+ if (data->active_low ^ assert)
+ val = mask;
+ else
+ val = ~mask;
+
+ return regmap_update_bits(regmap, data->reg, mask, val);
+}
+
+static int atlantis_reset_assert(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ return atlantis_reset_update(rcdev, id, true);
+}
+
+static int atlantis_reset_deassert(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ return atlantis_reset_update(rcdev, id, false);
+}
+
+static const struct reset_control_ops atlantis_reset_control_ops = {
+ .assert = atlantis_reset_assert,
+ .deassert = atlantis_reset_deassert,
+};
+
+static int
+atlantis_reset_controller_register(struct device *dev,
+ struct atlantis_reset_controller *controller)
+{
+ struct reset_controller_dev *rcdev = &controller->rcdev;
+
+ rcdev->ops = &atlantis_reset_control_ops;
+ rcdev->owner = THIS_MODULE;
+ rcdev->of_node = dev->of_node;
+ rcdev->nr_resets = controller->data->count;
+
+ return devm_reset_controller_register(dev, &controller->rcdev);
+}
+static int atlantis_reset_probe(struct auxiliary_device *adev,
+ const struct auxiliary_device_id *id)
+{
+ struct atlantis_ccu_adev *rdev = to_atlantis_ccu_adev(adev);
+ struct atlantis_reset_controller *controller;
+ struct device *dev = &adev->dev;
+
+ controller = devm_kzalloc(dev, sizeof(*controller), GFP_KERNEL);
+ if (!controller)
+ return -ENOMEM;
+ controller->data =
+ (const struct atlantis_reset_controller_data *)id->driver_data;
+ controller->regmap = rdev->regmap;
+
+ return atlantis_reset_controller_register(dev, controller);
+}
+
+static const struct auxiliary_device_id atlantis_reset_ids[] = {
+ { .name = "atlantis_ccu.rcpu-reset",
+ .driver_data = (kernel_ulong_t)&atlantis_rcpu_reset_data },
+ {},
+};
+MODULE_DEVICE_TABLE(auxiliary, atlantis_reset_ids);
+
+static struct auxiliary_driver atlantis_reset_driver = {
+ .probe = atlantis_reset_probe,
+ .id_table = atlantis_reset_ids,
+};
+module_auxiliary_driver(atlantis_reset_driver);
+
+MODULE_AUTHOR("Anirudh Srinivasan <asrinivasan@oss.tenstorrent.com>");
+MODULE_DESCRIPTION("Atlantis reset controller driver");
+MODULE_LICENSE("GPL");
diff --git a/include/soc/tenstorrent/atlantis-syscon.h b/include/soc/tenstorrent/atlantis-syscon.h
new file mode 100644
index 000000000000..2c6387e5c21a
--- /dev/null
+++ b/include/soc/tenstorrent/atlantis-syscon.h
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */
+/*
+ * Copyright (c) 2026 Tenstorrent
+ */
+#ifndef __SOC_ATLANTIS_SYSCON_H__
+#define __SOC_ATLANTIS_SYSCON_H__
+
+#include <linux/bits.h>
+#include <linux/types.h>
+
+struct atlantis_ccu_adev {
+ struct auxiliary_device adev;
+ struct regmap *regmap;
+};
+
+#define to_atlantis_ccu_adev(_adev) \
+ container_of((_adev), struct atlantis_ccu_adev, adev)
+
+/* RCPU Reset Register Offsets */
+#define RCPU_BLK_RST_REG 0x001c
+#define LSIO_BLK_RST_REG 0x0020
+#define HSIO_BLK_RST_REG 0x000c
+#define PCIE_SUBS_RST_REG 0x0000
+#define MM_RSTN_REG 0x0014
+
+#endif
--
2.43.0On Do, 2026-01-22 at 16:36 -0600, Anirudh Srinivasan wrote:
> Adds Atlantis Reset Controller and auxiliary device definitions for
> reset to share same regmap interface as clock controller.
>
> This version of the reset controller driver covers resets from the RCPU
> syscon.
>
> Signed-off-by: Anirudh Srinivasan <asrinivasan@oss.tenstorrent.com>
> ---
> MAINTAINERS | 2 +
> drivers/reset/Kconfig | 11 ++
> drivers/reset/Makefile | 1 +
> drivers/reset/reset-tenstorrent-atlantis.c | 158 +++++++++++++++++++++++++++++
> include/soc/tenstorrent/atlantis-syscon.h | 26 +++++
> 5 files changed, 198 insertions(+)
>
[...]
> diff --git a/drivers/reset/reset-tenstorrent-atlantis.c b/drivers/reset/reset-tenstorrent-atlantis.c
> new file mode 100644
> index 000000000000..2e7f09409f79
> --- /dev/null
> +++ b/drivers/reset/reset-tenstorrent-atlantis.c
> @@ -0,0 +1,158 @@
[...]
> +static int atlantis_reset_update(struct reset_controller_dev *rcdev,
> + unsigned long id, bool assert)
> +{
> + unsigned int val;
> + struct atlantis_reset_controller *rst =
> + to_atlantis_reset_controller(rcdev);
> + const struct atlantis_reset_data *data = &rst->data->reset_data[id];
> + unsigned int mask = BIT(data->bit);
> + struct regmap *regmap = rst->regmap;
> +
> + if (data->active_low ^ assert)
> + val = mask;
> + else
> + val = ~mask;
val = 0;
The ~mask bits will be ignored anyway.
[...]
> diff --git a/include/soc/tenstorrent/atlantis-syscon.h b/include/soc/tenstorrent/atlantis-syscon.h
> new file mode 100644
> index 000000000000..2c6387e5c21a
> --- /dev/null
> +++ b/include/soc/tenstorrent/atlantis-syscon.h
> @@ -0,0 +1,26 @@
> +/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */
> +/*
> + * Copyright (c) 2026 Tenstorrent
> + */
> +#ifndef __SOC_ATLANTIS_SYSCON_H__
> +#define __SOC_ATLANTIS_SYSCON_H__
> +
> +#include <linux/bits.h>
> +#include <linux/types.h>
#include <linux/auxiliary_bus.h>
struct regmap;
> +
> +struct atlantis_ccu_adev {
> + struct auxiliary_device adev;
> + struct regmap *regmap;
> +};
> +
> +#define to_atlantis_ccu_adev(_adev) \
> + container_of((_adev), struct atlantis_ccu_adev, adev)
Please use an inline function instead of a macro.
> +
> +/* RCPU Reset Register Offsets */
> +#define RCPU_BLK_RST_REG 0x001c
> +#define LSIO_BLK_RST_REG 0x0020
> +#define HSIO_BLK_RST_REG 0x000c
> +#define PCIE_SUBS_RST_REG 0x0000
> +#define MM_RSTN_REG 0x0014
Why not move these into reset-tenstorrent-atlantis.c, they are not part
of the interface between clock and reset drivers.
regards
Philipp
Hi Philipp,
On Fri, Jan 23, 2026 at 7:00 AM Philipp Zabel <p.zabel@pengutronix.de> wrote:
>
> On Do, 2026-01-22 at 16:36 -0600, Anirudh Srinivasan wrote:
> > Adds Atlantis Reset Controller and auxiliary device definitions for
> > reset to share same regmap interface as clock controller.
> >
> > + if (data->active_low ^ assert)
> > + val = mask;
> > + else
> > + val = ~mask;
>
> val = 0;
>
> The ~mask bits will be ignored anyway.
Ack. Will change.
>
> struct regmap;
>
> > +
> > +struct atlantis_ccu_adev {
> > + struct auxiliary_device adev;
> > + struct regmap *regmap;
> > +};
> > +
> > +#define to_atlantis_ccu_adev(_adev) \
> > + container_of((_adev), struct atlantis_ccu_adev, adev)
>
> Please use an inline function instead of a macro.
Ack.
>
> > +
> > +/* RCPU Reset Register Offsets */
> > +#define RCPU_BLK_RST_REG 0x001c
> > +#define LSIO_BLK_RST_REG 0x0020
> > +#define HSIO_BLK_RST_REG 0x000c
> > +#define PCIE_SUBS_RST_REG 0x0000
> > +#define MM_RSTN_REG 0x0014
>
> Why not move these into reset-tenstorrent-atlantis.c, they are not part
> of the interface between clock and reset drivers.
We were considering putting register offsets like this in separate
header files that are dual licensed. In that case, is it okay to put
it here?
>
> regards
> Philipp
On Fr, 2026-01-23 at 10:15 -0600, Anirudh Srinivasan wrote: > > > +/* RCPU Reset Register Offsets */ > > > +#define RCPU_BLK_RST_REG 0x001c > > > +#define LSIO_BLK_RST_REG 0x0020 > > > +#define HSIO_BLK_RST_REG 0x000c > > > +#define PCIE_SUBS_RST_REG 0x0000 > > > +#define MM_RSTN_REG 0x0014 > > > > Why not move these into reset-tenstorrent-atlantis.c, they are not part > > of the interface between clock and reset drivers. > > We were considering putting register offsets like this in separate > header files that are dual licensed. In that case, is it okay to put > it here? I see, nothing wrong with that. regards Philipp
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