* [PATCH v28 1/4] dt-bindings: i2c: Split AST2600 binding into a new YAML
2026-03-30 8:21 [PATCH v28 0/4] Add ASPEED AST2600 I2C controller driver Ryan Chen
@ 2026-03-30 8:21 ` Ryan Chen
2026-03-30 8:21 ` [PATCH v28 2/4] dt-bindings: i2c: ast2600-i2c.yaml: Add global-regs and enable-dma properties Ryan Chen
` (2 subsequent siblings)
3 siblings, 0 replies; 11+ messages in thread
From: Ryan Chen @ 2026-03-30 8:21 UTC (permalink / raw)
To: jk, andriy.shevchenko, Andi Shyti, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Joel Stanley, Andrew Jeffery,
Benjamin Herrenschmidt, Rayn Chen, Philipp Zabel
Cc: linux-i2c, devicetree, linux-arm-kernel, linux-aspeed,
linux-kernel, openbmc, Ryan Chen
The AST2600 I2C controller introduces a completely new register layout
with separate controller and target register blocks, unlike the mixed
register layout used by AST2400/AST2500.
Move AST2600 I2C binding from aspeed,i2c.yaml to a dedicated
aspeed,ast2600-i2c.yaml schema.
Besides the split, this also adjusts for AST2600-specific requirements.
- require two reg regions (controller register block + buffer block)
- use clock-frequency for bus speed description
- interrupts are required on AST2600
- use correct DTS coding style in example
No compatible strings are changed.
Signed-off-by: Ryan Chen <ryan_chen@aspeedtech.com>
---
Changes in v26:
- commit message: include details of changes from original binding
- fix example property ordering to follow DTS coding style
- use consistent "AST2600" naming
---
.../bindings/i2c/aspeed,ast2600-i2c.yaml | 62 ++++++++++++++++++++++
.../devicetree/bindings/i2c/aspeed,i2c.yaml | 3 +-
2 files changed, 63 insertions(+), 2 deletions(-)
diff --git a/Documentation/devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml b/Documentation/devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml
new file mode 100644
index 000000000000..de2c359037da
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml
@@ -0,0 +1,62 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/i2c/aspeed,ast2600-i2c.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ASPEED I2C on the AST2600 SoCs
+
+maintainers:
+ - Ryan Chen <ryan_chen@aspeedtech.com>
+
+allOf:
+ - $ref: /schemas/i2c/i2c-controller.yaml#
+
+properties:
+ compatible:
+ enum:
+ - aspeed,ast2600-i2c-bus
+
+ reg:
+ items:
+ - description: controller registers
+ - description: controller buffer space
+
+ interrupts:
+ maxItems: 1
+
+ clocks:
+ maxItems: 1
+
+ clock-frequency:
+ description: Desired operating frequency of the I2C bus in Hz.
+ minimum: 500
+ maximum: 4000000
+ default: 100000
+
+ resets:
+ maxItems: 1
+
+required:
+ - reg
+ - compatible
+ - clocks
+ - resets
+ - interrupts
+
+unevaluatedProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/clock/aspeed-clock.h>
+ #include <dt-bindings/interrupt-controller/arm-gic.h>
+ i2c@80 {
+ compatible = "aspeed,ast2600-i2c-bus";
+ reg = <0x80 0x80>, <0xc00 0x20>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+ clocks = <&syscon ASPEED_CLK_APB>;
+ resets = <&syscon ASPEED_RESET_I2C>;
+ clock-frequency = <100000>;
+ interrupts = <GIC_SPI 110 IRQ_TYPE_LEVEL_HIGH>;
+ };
diff --git a/Documentation/devicetree/bindings/i2c/aspeed,i2c.yaml b/Documentation/devicetree/bindings/i2c/aspeed,i2c.yaml
index 5b9bd2feda3b..d4e4f412feba 100644
--- a/Documentation/devicetree/bindings/i2c/aspeed,i2c.yaml
+++ b/Documentation/devicetree/bindings/i2c/aspeed,i2c.yaml
@@ -4,7 +4,7 @@
$id: http://devicetree.org/schemas/i2c/aspeed,i2c.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
-title: ASPEED I2C on the AST24XX, AST25XX, and AST26XX SoCs
+title: ASPEED I2C on the AST24XX, AST25XX SoCs
maintainers:
- Rayn Chen <rayn_chen@aspeedtech.com>
@@ -17,7 +17,6 @@ properties:
enum:
- aspeed,ast2400-i2c-bus
- aspeed,ast2500-i2c-bus
- - aspeed,ast2600-i2c-bus
reg:
minItems: 1
--
2.34.1
^ permalink raw reply related [flat|nested] 11+ messages in thread* [PATCH v28 2/4] dt-bindings: i2c: ast2600-i2c.yaml: Add global-regs and enable-dma properties
2026-03-30 8:21 [PATCH v28 0/4] Add ASPEED AST2600 I2C controller driver Ryan Chen
2026-03-30 8:21 ` [PATCH v28 1/4] dt-bindings: i2c: Split AST2600 binding into a new YAML Ryan Chen
@ 2026-03-30 8:21 ` Ryan Chen
2026-03-31 6:47 ` Krzysztof Kozlowski
2026-03-30 8:21 ` [PATCH v28 3/4] i2c: ast2600: Add controller driver for AST2600 new register set Ryan Chen
2026-03-30 8:21 ` [PATCH v28 4/4] i2c: ast2600: Add target mode support Ryan Chen
3 siblings, 1 reply; 11+ messages in thread
From: Ryan Chen @ 2026-03-30 8:21 UTC (permalink / raw)
To: jk, andriy.shevchenko, Andi Shyti, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Joel Stanley, Andrew Jeffery,
Benjamin Herrenschmidt, Rayn Chen, Philipp Zabel
Cc: linux-i2c, devicetree, linux-arm-kernel, linux-aspeed,
linux-kernel, openbmc, Ryan Chen
Add aspeed,enable-dma boolean property to indicate that DMA is
available for transfers on this I2C bus.
Also add the aspeed,global-regs phandle to reference the AST2600
global registers syscon node, containing the SoC-common I2C register
set.
These properties apply only to the AST2600 binding. Legacy DTs remain
unchanged.
Signed-off-by: Ryan Chen <ryan_chen@aspeedtech.com>
---
Changes in v28:
- update commit message correspond with aspeed,enable-dma.
- remove aspeed,transfer-mode and add aspeed,enable-dma property and
description.
- Fix aspeed,enable-dma description to reflect hardware capability rather
than software behavior
Changes in v27:
- change aspeed,transfer-mode to aspeed,enable-dma.
---
.../devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/Documentation/devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml b/Documentation/devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml
index de2c359037da..67b23d1a4cec 100644
--- a/Documentation/devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml
+++ b/Documentation/devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml
@@ -37,6 +37,16 @@ properties:
resets:
maxItems: 1
+ aspeed,enable-dma:
+ type: boolean
+ description: Indicates this I2C controller instance has DMA capability.
+
+ aspeed,global-regs:
+ $ref: /schemas/types.yaml#/definitions/phandle
+ description:
+ Phandle reference to the i2c global syscon node, containing the
+ SoC-common i2c register set.
+
required:
- reg
- compatible
@@ -59,4 +69,6 @@ examples:
resets = <&syscon ASPEED_RESET_I2C>;
clock-frequency = <100000>;
interrupts = <GIC_SPI 110 IRQ_TYPE_LEVEL_HIGH>;
+ aspeed,global-regs = <&i2c_global>;
+ aspeed,enable-dma;
};
--
2.34.1
^ permalink raw reply related [flat|nested] 11+ messages in thread* Re: [PATCH v28 2/4] dt-bindings: i2c: ast2600-i2c.yaml: Add global-regs and enable-dma properties
2026-03-30 8:21 ` [PATCH v28 2/4] dt-bindings: i2c: ast2600-i2c.yaml: Add global-regs and enable-dma properties Ryan Chen
@ 2026-03-31 6:47 ` Krzysztof Kozlowski
2026-03-31 6:58 ` Ryan Chen
0 siblings, 1 reply; 11+ messages in thread
From: Krzysztof Kozlowski @ 2026-03-31 6:47 UTC (permalink / raw)
To: Ryan Chen
Cc: jk, andriy.shevchenko, Andi Shyti, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Joel Stanley, Andrew Jeffery,
Benjamin Herrenschmidt, Rayn Chen, Philipp Zabel, linux-i2c,
devicetree, linux-arm-kernel, linux-aspeed, linux-kernel, openbmc
On Mon, Mar 30, 2026 at 04:21:47PM +0800, Ryan Chen wrote:
> Add aspeed,enable-dma boolean property to indicate that DMA is
> available for transfers on this I2C bus.
>
> Also add the aspeed,global-regs phandle to reference the AST2600
> global registers syscon node, containing the SoC-common I2C register
> set.
>
> These properties apply only to the AST2600 binding. Legacy DTs remain
> unchanged.
>
> Signed-off-by: Ryan Chen <ryan_chen@aspeedtech.com>
> ---
> Changes in v28:
> - update commit message correspond with aspeed,enable-dma.
> - remove aspeed,transfer-mode and add aspeed,enable-dma property and
> description.
> - Fix aspeed,enable-dma description to reflect hardware capability rather
> than software behavior
> Changes in v27:
> - change aspeed,transfer-mode to aspeed,enable-dma.
> ---
> .../devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml b/Documentation/devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml
> index de2c359037da..67b23d1a4cec 100644
> --- a/Documentation/devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml
> +++ b/Documentation/devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml
> @@ -37,6 +37,16 @@ properties:
> resets:
> maxItems: 1
>
> + aspeed,enable-dma:
> + type: boolean
> + description: Indicates this I2C controller instance has DMA capability.
Compatible implies that "I2C controller instance has DMA capability", no?
How two same devices, with exactly the same or compatible programming
model can have difference in the programming model for DMA (one lacks
it)?
Best regards,
Krzysztof
^ permalink raw reply [flat|nested] 11+ messages in thread
* RE: [PATCH v28 2/4] dt-bindings: i2c: ast2600-i2c.yaml: Add global-regs and enable-dma properties
2026-03-31 6:47 ` Krzysztof Kozlowski
@ 2026-03-31 6:58 ` Ryan Chen
2026-03-31 7:00 ` Jeremy Kerr
0 siblings, 1 reply; 11+ messages in thread
From: Ryan Chen @ 2026-03-31 6:58 UTC (permalink / raw)
To: Krzysztof Kozlowski
Cc: jk@codeconstruct.com.au, andriy.shevchenko@linux.intel.com,
Andi Shyti, Rob Herring, Krzysztof Kozlowski, Conor Dooley,
Joel Stanley, Andrew Jeffery, Benjamin Herrenschmidt,
Philipp Zabel, linux-i2c@vger.kernel.org,
devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-aspeed@lists.ozlabs.org, linux-kernel@vger.kernel.org,
openbmc@lists.ozlabs.org
> Subject: Re: [PATCH v28 2/4] dt-bindings: i2c: ast2600-i2c.yaml: Add global-regs
> and enable-dma properties
>
> On Mon, Mar 30, 2026 at 04:21:47PM +0800, Ryan Chen wrote:
> > Add aspeed,enable-dma boolean property to indicate that DMA is
> > available for transfers on this I2C bus.
> >
> > Also add the aspeed,global-regs phandle to reference the AST2600
> > global registers syscon node, containing the SoC-common I2C register
> > set.
> >
> > These properties apply only to the AST2600 binding. Legacy DTs remain
> > unchanged.
> >
> > Signed-off-by: Ryan Chen <ryan_chen@aspeedtech.com>
> > ---
> > Changes in v28:
> > - update commit message correspond with aspeed,enable-dma.
> > - remove aspeed,transfer-mode and add aspeed,enable-dma property and
> > description.
> > - Fix aspeed,enable-dma description to reflect hardware capability rather
> > than software behavior
> > Changes in v27:
> > - change aspeed,transfer-mode to aspeed,enable-dma.
> > ---
> > .../devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml | 12
> ++++++++++++
> > 1 file changed, 12 insertions(+)
> >
> > diff --git
> > a/Documentation/devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml
> > b/Documentation/devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml
> > index de2c359037da..67b23d1a4cec 100644
> > --- a/Documentation/devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml
> > +++ b/Documentation/devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml
> > @@ -37,6 +37,16 @@ properties:
> > resets:
> > maxItems: 1
> >
> > + aspeed,enable-dma:
> > + type: boolean
> > + description: Indicates this I2C controller instance has DMA capability.
>
> Compatible implies that "I2C controller instance has DMA capability", no?
>
> How two same devices, with exactly the same or compatible programming
> model can have difference in the programming model for DMA (one lacks it)?
>
> Best regards,
> Krzysztof
Thanks your review.
All AST2600 I2C controller instances have DMA hardware.
I will remove the aspeed,enable-dma property and instead expose sysfs
attribute in driver to allow users to enable dma/buffer/byte.
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH v28 2/4] dt-bindings: i2c: ast2600-i2c.yaml: Add global-regs and enable-dma properties
2026-03-31 6:58 ` Ryan Chen
@ 2026-03-31 7:00 ` Jeremy Kerr
2026-03-31 7:09 ` Ryan Chen
0 siblings, 1 reply; 11+ messages in thread
From: Jeremy Kerr @ 2026-03-31 7:00 UTC (permalink / raw)
To: Ryan Chen, Krzysztof Kozlowski
Cc: andriy.shevchenko@linux.intel.com, Andi Shyti, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Joel Stanley, Andrew Jeffery,
Benjamin Herrenschmidt, Philipp Zabel, linux-i2c@vger.kernel.org,
devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-aspeed@lists.ozlabs.org, linux-kernel@vger.kernel.org,
openbmc@lists.ozlabs.org
Hi Ryan,
> All AST2600 I2C controller instances have DMA hardware.
> I will remove the aspeed,enable-dma property and instead expose sysfs
> attribute in driver to allow users to enable dma/buffer/byte.
Sounds reasonable, but before you do so, how are you planning to manage
the allocation of DMA channels across multiple i2c peripherals?
Cheers,
Jeremy
^ permalink raw reply [flat|nested] 11+ messages in thread
* RE: [PATCH v28 2/4] dt-bindings: i2c: ast2600-i2c.yaml: Add global-regs and enable-dma properties
2026-03-31 7:00 ` Jeremy Kerr
@ 2026-03-31 7:09 ` Ryan Chen
2026-03-31 7:17 ` Jeremy Kerr
0 siblings, 1 reply; 11+ messages in thread
From: Ryan Chen @ 2026-03-31 7:09 UTC (permalink / raw)
To: Jeremy Kerr, Krzysztof Kozlowski
Cc: andriy.shevchenko@linux.intel.com, Andi Shyti, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Joel Stanley, Andrew Jeffery,
Benjamin Herrenschmidt, Philipp Zabel, linux-i2c@vger.kernel.org,
devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-aspeed@lists.ozlabs.org, linux-kernel@vger.kernel.org,
openbmc@lists.ozlabs.org
> Subject: Re: [PATCH v28 2/4] dt-bindings: i2c: ast2600-i2c.yaml: Add global-regs
> and enable-dma properties
>
> Hi Ryan,
>
> > All AST2600 I2C controller instances have DMA hardware.
> > I will remove the aspeed,enable-dma property and instead expose sysfs
> > attribute in driver to allow users to enable dma/buffer/byte.
>
> Sounds reasonable, but before you do so, how are you planning to manage the
> allocation of DMA channels across multiple i2c peripherals?
>
The AST2600 I2C hardware has only one can use DMA at a time.
To avoid the complexity of managing DMA channel contention,
I plan to use buffer mode by default for all controllers, which still provides
better performance than byte mode without requiring DMA channel allocation.
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH v28 2/4] dt-bindings: i2c: ast2600-i2c.yaml: Add global-regs and enable-dma properties
2026-03-31 7:09 ` Ryan Chen
@ 2026-03-31 7:17 ` Jeremy Kerr
2026-03-31 7:30 ` Ryan Chen
0 siblings, 1 reply; 11+ messages in thread
From: Jeremy Kerr @ 2026-03-31 7:17 UTC (permalink / raw)
To: Ryan Chen, Krzysztof Kozlowski
Cc: andriy.shevchenko@linux.intel.com, Andi Shyti, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Joel Stanley, Andrew Jeffery,
Benjamin Herrenschmidt, Philipp Zabel, linux-i2c@vger.kernel.org,
devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-aspeed@lists.ozlabs.org, linux-kernel@vger.kernel.org,
openbmc@lists.ozlabs.org
Hi Ryan,
> > Sounds reasonable, but before you do so, how are you planning to manage the
> > allocation of DMA channels across multiple i2c peripherals?
> >
> The AST2600 I2C hardware has only one can use DMA at a time.
> To avoid the complexity of managing DMA channel contention,
> I plan to use buffer mode by default for all controllers, which still provides
> better performance than byte mode without requiring DMA channel allocation.
OK, but your wording there ("by default") implies that DMA is still
selectable for one controller peripheral. In which case: you still have
the problem of managing DMA channel contention, but now it's at runtime
instead.
So my question still stands: how are you planning to enforce that DMA is
only enabled for one controller?
Or are you planning to disable I2C DMA entirely on AST2600?
Cheers,
Jeremy
^ permalink raw reply [flat|nested] 11+ messages in thread* RE: [PATCH v28 2/4] dt-bindings: i2c: ast2600-i2c.yaml: Add global-regs and enable-dma properties
2026-03-31 7:17 ` Jeremy Kerr
@ 2026-03-31 7:30 ` Ryan Chen
0 siblings, 0 replies; 11+ messages in thread
From: Ryan Chen @ 2026-03-31 7:30 UTC (permalink / raw)
To: Jeremy Kerr, Krzysztof Kozlowski
Cc: andriy.shevchenko@linux.intel.com, Andi Shyti, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Joel Stanley, Andrew Jeffery,
Benjamin Herrenschmidt, Philipp Zabel, linux-i2c@vger.kernel.org,
devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-aspeed@lists.ozlabs.org, linux-kernel@vger.kernel.org,
openbmc@lists.ozlabs.org
> Subject: Re: [PATCH v28 2/4] dt-bindings: i2c: ast2600-i2c.yaml: Add global-regs
> and enable-dma properties
>
> Hi Ryan,
>
> > > Sounds reasonable, but before you do so, how are you planning to
> > > manage the allocation of DMA channels across multiple i2c peripherals?
> > >
> > The AST2600 I2C hardware has only one can use DMA at a time.
> > To avoid the complexity of managing DMA channel contention, I plan to
> > use buffer mode by default for all controllers, which still provides
> > better performance than byte mode without requiring DMA channel
> allocation.
>
> OK, but your wording there ("by default") implies that DMA is still selectable
> for one controller peripheral. In which case: you still have the problem of
> managing DMA channel contention, but now it's at runtime instead.
>
> So my question still stands: how are you planning to enforce that DMA is only
> enabled for one controller?
>
> Or are you planning to disable I2C DMA entirely on AST2600?
Yes, This is my intent to do.
Disable I2C DMA entirely on AST2600.
If I remove DMA, should can I keep byte and buffer for sysfs?
^ permalink raw reply [flat|nested] 11+ messages in thread
* [PATCH v28 3/4] i2c: ast2600: Add controller driver for AST2600 new register set
2026-03-30 8:21 [PATCH v28 0/4] Add ASPEED AST2600 I2C controller driver Ryan Chen
2026-03-30 8:21 ` [PATCH v28 1/4] dt-bindings: i2c: Split AST2600 binding into a new YAML Ryan Chen
2026-03-30 8:21 ` [PATCH v28 2/4] dt-bindings: i2c: ast2600-i2c.yaml: Add global-regs and enable-dma properties Ryan Chen
@ 2026-03-30 8:21 ` Ryan Chen
2026-03-30 8:21 ` [PATCH v28 4/4] i2c: ast2600: Add target mode support Ryan Chen
3 siblings, 0 replies; 11+ messages in thread
From: Ryan Chen @ 2026-03-30 8:21 UTC (permalink / raw)
To: jk, andriy.shevchenko, Andi Shyti, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Joel Stanley, Andrew Jeffery,
Benjamin Herrenschmidt, Rayn Chen, Philipp Zabel
Cc: linux-i2c, devicetree, linux-arm-kernel, linux-aspeed,
linux-kernel, openbmc, Ryan Chen
The AST2600 introduces a new I2C controller register layout, selectable
at runtime via global control registers. Compared to the legacy layout
used on AST2400/AST2500, the new layout separates controller (master)
and target (slave) registers and adds support for packet-based transfers
The new register set extends the hardware capabilities with:
- Enhanced clock divider configuration for improved timing precision
- tCKHighMin timing control for SCL high pulse width
- Dual pool buffer mode (separate Tx/Rx buffers)
- Extended DMA support with larger buffer size and alignment handling
- Dedicated DMA buffers for controller and target directions
- Hardware-assisted bus recovery and timeout mechanisms
This patch adds an AST2600-specific I2C controller driver implementing
the new register layout, including support for packet-based transfers
and byte, buffer and DMA transfer modes.
The legacy and new register layouts represent the same AST2600 I2C
controller IP and therefore share the existing compatible string:
"aspeed,ast2600-i2c-bus"
To preserve DT ABI compatibility, driver selection is performed at probe
time based on DT contents. In particular, the new binding requires the
`aspeed,global-regs` phandle, which is absent from legacy DTBs:
- The new driver only probes successfully when `aspeed,global-regs` is
present.
- The existing i2c-aspeed driver returns -ENODEV for AST2600 nodes that
provide `aspeed,global-regs`, allowing the new driver to bind.
Signed-off-by: Ryan Chen <ryan_chen@aspeedtech.com>
---
Changes in v28:
- Separate xfer_mode_store into distinct parse and availability-check
steps by introducing ast2600_i2c_xfer_mode_check()
- fix tx dma memcpy source point address.
- Use a temporary variable for devm_platform_get_and_ioremap_resource()
to avoid storing an ERR_PTR in i2c_bus->buf_base; drop the redundant
NULL assignment in the error path since i2c_bus is kzalloc()ed
- Add ABI documentation file
Documentation/ABI/testing/sysfs-driver-ast2600-i2c
Changes in v27:
- remove aspeed,transfer-mode selection instead aspeed,dma-mode.
- add sysfs for xfer mode.
Changes in v25:
- Rename AST2600_I2CM_SMBUS_ALT to AST2600_I2CM_SMBUS_ALERT.
- Refactor transfer mode handling using setup_tx/setup_rx helpers.
- Rework DMA handling to use pre-allocated buffers and reduce
mapping overhead in interrupt context.
- Fix IRQ status checks to use consistent (sts & value) style.
- Move device_property_read_bool() to probe().
- Improve probe error handling.
- Handle timeout condition in target_byte_irq().
- Rename "package" to "packet".
- Remove target reset when master wait_for_completion_timeout().
---
Documentation/ABI/testing/sysfs-driver-ast2600-i2c | 19 +
drivers/i2c/busses/Makefile | 2 +-
drivers/i2c/busses/i2c-aspeed.c | 5 +
drivers/i2c/busses/i2c-ast2600.c | 1080 ++++++++++++++++++++
4 files changed, 1105 insertions(+), 1 deletion(-)
diff --git a/Documentation/ABI/testing/sysfs-driver-ast2600-i2c b/Documentation/ABI/testing/sysfs-driver-ast2600-i2c
new file mode 100644
index 000000000000..7d2a69a7281a
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-driver-ast2600-i2c
@@ -0,0 +1,19 @@
+What: /sys/bus/platform/drivers/i2c-ast2600/.../xfer_mode
+Date: March 2026
+KernelVersion: 7.x
+Contact: Ryan Chen <ryan_chen@aspeedtech.com>
+Description: Shows or sets the active transfer mode for an ASPEED AST2600
+ I2C controller instance.
+
+ Possible values:
+
+ ========= =================================================
+ byte Programmed I/O, one byte at a time.
+ buffer Programmed I/O using the hardware FIFO buffer.
+ Only available if the controller has a buffer
+ resource defined in the device tree.
+ dma DMA transfer (if DMA is available for this
+ controller).
+ ========= =================================================
+
+ Writing an unsupported or unavailable mode returns -EINVAL.
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 547123ab351f..ece201a67d41 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -37,7 +37,7 @@ obj-$(CONFIG_I2C_POWERMAC) += i2c-powermac.o
obj-$(CONFIG_I2C_ALTERA) += i2c-altera.o
obj-$(CONFIG_I2C_AMD_MP2) += i2c-amd-mp2-pci.o i2c-amd-mp2-plat.o
obj-$(CONFIG_I2C_AMD_ASF) += i2c-amd-asf-plat.o
-obj-$(CONFIG_I2C_ASPEED) += i2c-aspeed.o
+obj-$(CONFIG_I2C_ASPEED) += i2c-aspeed.o i2c-ast2600.o
obj-$(CONFIG_I2C_AT91) += i2c-at91.o
i2c-at91-y := i2c-at91-core.o i2c-at91-master.o
i2c-at91-$(CONFIG_I2C_AT91_SLAVE_EXPERIMENTAL) += i2c-at91-slave.o
diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c
index a26b74c71206..8286fd2cd130 100644
--- a/drivers/i2c/busses/i2c-aspeed.c
+++ b/drivers/i2c/busses/i2c-aspeed.c
@@ -22,6 +22,7 @@
#include <linux/of_irq.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
+#include <linux/property.h>
#include <linux/reset.h>
#include <linux/slab.h>
@@ -1002,6 +1003,10 @@ static int aspeed_i2c_probe_bus(struct platform_device *pdev)
struct clk *parent_clk;
int irq, ret;
+ if (device_is_compatible(&pdev->dev, "aspeed,ast2600-i2c-bus") &&
+ device_property_present(&pdev->dev, "aspeed,global-regs"))
+ return -ENODEV;
+
bus = devm_kzalloc(&pdev->dev, sizeof(*bus), GFP_KERNEL);
if (!bus)
return -ENOMEM;
diff --git a/drivers/i2c/busses/i2c-ast2600.c b/drivers/i2c/busses/i2c-ast2600.c
new file mode 100644
index 000000000000..c2368ba309a7
--- /dev/null
+++ b/drivers/i2c/busses/i2c-ast2600.c
@@ -0,0 +1,1080 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ASPEED AST2600 new register set I2C controller driver
+ *
+ * Copyright (C) 2026 ASPEED Technology Inc.
+ */
+#include <linux/array_size.h>
+#include <linux/bits.h>
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/i2c-smbus.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/minmax.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include <linux/reset.h>
+#include <linux/slab.h>
+#include <linux/string_helpers.h>
+#include <linux/unaligned.h>
+
+#define AST2600_I2CG_ISR 0x00
+#define AST2600_I2CG_SLAVE_ISR 0x04
+#define AST2600_I2CG_OWNER 0x08
+#define AST2600_I2CG_CTRL 0x0C
+#define AST2600_I2CG_CLK_DIV_CTRL 0x10
+
+#define AST2600_I2CG_SLAVE_PKT_NAK BIT(4)
+#define AST2600_I2CG_M_S_SEPARATE_INTR BIT(3)
+#define AST2600_I2CG_CTRL_NEW_REG BIT(2)
+#define AST2600_I2CG_CTRL_NEW_CLK_DIV BIT(1)
+#define AST2600_GLOBAL_INIT \
+ (AST2600_I2CG_CTRL_NEW_REG | AST2600_I2CG_CTRL_NEW_CLK_DIV)
+/*
+ * APB clk : 100Mhz
+ * div : scl : baseclk [APB/((div/2) + 1)] : tBuf [1/bclk * 16]
+ * I2CG10[31:24] base clk4 for i2c auto recovery timeout counter (0xC6)
+ * I2CG10[23:16] base clk3 for Standard-mode (100Khz) min tBuf 4.7us
+ * 0x3c : 100.8Khz : 3.225Mhz : 4.96us
+ * 0x3d : 99.2Khz : 3.174Mhz : 5.04us
+ * 0x3e : 97.65Khz : 3.125Mhz : 5.12us
+ * 0x40 : 97.75Khz : 3.03Mhz : 5.28us
+ * 0x41 : 99.5Khz : 2.98Mhz : 5.36us (default)
+ * I2CG10[15:8] base clk2 for Fast-mode (400Khz) min tBuf 1.3us
+ * 0x12 : 400Khz : 10Mhz : 1.6us
+ * I2CG10[7:0] base clk1 for Fast-mode Plus (1Mhz) min tBuf 0.5us
+ * 0x08 : 1Mhz : 20Mhz : 0.8us
+ */
+#define I2CCG_DIV_CTRL 0xC6411208
+
+/* 0x00 : I2CC Controller/Target Function Control Register */
+#define AST2600_I2CC_FUN_CTRL 0x00
+#define AST2600_I2CC_SLAVE_ADDR_RX_EN BIT(20)
+#define AST2600_I2CC_MASTER_RETRY_MASK GENMASK(19, 18)
+#define AST2600_I2CC_MASTER_RETRY(x) (((x) & GENMASK(1, 0)) << 18)
+#define AST2600_I2CC_BUS_AUTO_RELEASE BIT(17)
+#define AST2600_I2CC_M_SDA_LOCK_EN BIT(16)
+#define AST2600_I2CC_MULTI_MASTER_DIS BIT(15)
+#define AST2600_I2CC_M_SCL_DRIVE_EN BIT(14)
+#define AST2600_I2CC_MSB_STS BIT(9)
+#define AST2600_I2CC_SDA_DRIVE_1T_EN BIT(8)
+#define AST2600_I2CC_M_SDA_DRIVE_1T_EN BIT(7)
+#define AST2600_I2CC_M_HIGH_SPEED_EN BIT(6)
+/* reserver 5 : 2 */
+#define AST2600_I2CC_SLAVE_EN BIT(1)
+#define AST2600_I2CC_MASTER_EN BIT(0)
+
+/* 0x04 : I2CC Controller/Target Clock and AC Timing Control Register #1 */
+#define AST2600_I2CC_AC_TIMING 0x04
+#define AST2600_I2CC_TTIMEOUT(x) (((x) & GENMASK(4, 0)) << 24)
+#define AST2600_I2CC_TCKHIGHMIN(x) (((x) & GENMASK(3, 0)) << 20)
+#define AST2600_I2CC_TCKHIGH(x) (((x) & GENMASK(3, 0)) << 16)
+#define AST2600_I2CC_TCKLOW(x) (((x) & GENMASK(3, 0)) << 12)
+#define AST2600_I2CC_THDDAT(x) (((x) & GENMASK(1, 0)) << 10)
+#define AST2600_I2CC_TOUTBASECLK(x) (((x) & GENMASK(1, 0)) << 8)
+#define AST2600_I2CC_TBASECLK(x) ((x) & GENMASK(3, 0))
+#define AST2600_I2CC_AC_TIMING_MASK GENMASK(23, 0)
+
+/* 0x08 : I2CC Controller/Target Transmit/Receive Byte Buffer Register */
+#define AST2600_I2CC_STS_AND_BUFF 0x08
+#define AST2600_I2CC_TX_DIR_MASK GENMASK(31, 29)
+#define AST2600_I2CC_SDA_OE BIT(28)
+#define AST2600_I2CC_SDA_O BIT(27)
+#define AST2600_I2CC_SCL_OE BIT(26)
+#define AST2600_I2CC_SCL_O BIT(25)
+
+#define AST2600_I2CC_SCL_LINE_STS BIT(18)
+#define AST2600_I2CC_SDA_LINE_STS BIT(17)
+#define AST2600_I2CC_BUS_BUSY_STS BIT(16)
+
+#define AST2600_I2CC_GET_RX_BUFF(x) (((x) >> 8) & GENMASK(7, 0))
+
+/* 0x0C : I2CC Controller/Target Pool Buffer Control Register */
+#define AST2600_I2CC_BUFF_CTRL 0x0C
+#define AST2600_I2CC_GET_RX_BUF_LEN(x) (((x) & GENMASK(29, 24)) >> 24)
+#define AST2600_I2CC_SET_RX_BUF_LEN(x) (((((x) - 1) & GENMASK(4, 0)) << 16) | BIT(0))
+#define AST2600_I2CC_SET_TX_BUF_LEN(x) (((((x) - 1) & GENMASK(4, 0)) << 8) | BIT(0))
+#define AST2600_I2CC_GET_TX_BUF_LEN(x) ((((x) & GENMASK(12, 8)) >> 8) + 1)
+
+/* 0x10 : I2CM Controller Interrupt Control Register */
+#define AST2600_I2CM_IER 0x10
+/* 0x14 : I2CM Controller Interrupt Status Register : WC */
+#define AST2600_I2CM_ISR 0x14
+
+#define AST2600_I2CM_PKT_TIMEOUT BIT(18)
+#define AST2600_I2CM_PKT_ERROR BIT(17)
+#define AST2600_I2CM_PKT_DONE BIT(16)
+
+#define AST2600_I2CM_BUS_RECOVER_FAIL BIT(15)
+#define AST2600_I2CM_SDA_DL_TO BIT(14)
+#define AST2600_I2CM_BUS_RECOVER BIT(13)
+#define AST2600_I2CM_SMBUS_ALERT BIT(12)
+
+#define AST2600_I2CM_SCL_LOW_TO BIT(6)
+#define AST2600_I2CM_ABNORMAL BIT(5)
+#define AST2600_I2CM_NORMAL_STOP BIT(4)
+#define AST2600_I2CM_ARBIT_LOSS BIT(3)
+#define AST2600_I2CM_RX_DONE BIT(2)
+#define AST2600_I2CM_TX_NAK BIT(1)
+#define AST2600_I2CM_TX_ACK BIT(0)
+
+/* 0x18 : I2CM Controller Command/Status Register */
+#define AST2600_I2CM_CMD_STS 0x18
+#define AST2600_I2CM_PKT_ADDR(x) (((x) & GENMASK(6, 0)) << 24)
+#define AST2600_I2CM_PKT_EN BIT(16)
+#define AST2600_I2CM_SDA_OE_OUT_DIR BIT(15)
+#define AST2600_I2CM_SDA_O_OUT_DIR BIT(14)
+#define AST2600_I2CM_SCL_OE_OUT_DIR BIT(13)
+#define AST2600_I2CM_SCL_O_OUT_DIR BIT(12)
+#define AST2600_I2CM_RECOVER_CMD_EN BIT(11)
+
+#define AST2600_I2CM_RX_DMA_EN BIT(9)
+#define AST2600_I2CM_TX_DMA_EN BIT(8)
+/* Command Bit */
+#define AST2600_I2CM_RX_BUFF_EN BIT(7)
+#define AST2600_I2CM_TX_BUFF_EN BIT(6)
+#define AST2600_I2CM_STOP_CMD BIT(5)
+#define AST2600_I2CM_RX_CMD_LAST BIT(4)
+#define AST2600_I2CM_RX_CMD BIT(3)
+
+#define AST2600_I2CM_TX_CMD BIT(1)
+#define AST2600_I2CM_START_CMD BIT(0)
+
+/* 0x1C : I2CM Controller DMA Transfer Length Register */
+#define AST2600_I2CM_DMA_LEN 0x1C
+/* Tx Rx support length 1 ~ 4096 */
+#define AST2600_I2CM_SET_RX_DMA_LEN(x) ((((x) & GENMASK(11, 0)) << 16) | BIT(31))
+#define AST2600_I2CM_SET_TX_DMA_LEN(x) (((x) & GENMASK(11, 0)) | BIT(15))
+
+/* 0x20 : I2CS Target Interrupt Control Register */
+#define AST2600_I2CS_IER 0x20
+/* 0x24 : I2CS Target Interrupt Status Register */
+#define AST2600_I2CS_ISR 0x24
+
+#define AST2600_I2CS_ADDR_INDICATE_MASK GENMASK(31, 30)
+#define AST2600_I2CS_SLAVE_PENDING BIT(29)
+
+#define AST2600_I2CS_WAIT_TX_DMA BIT(25)
+#define AST2600_I2CS_WAIT_RX_DMA BIT(24)
+
+#define AST2600_I2CS_ADDR3_NAK BIT(22)
+#define AST2600_I2CS_ADDR2_NAK BIT(21)
+#define AST2600_I2CS_ADDR1_NAK BIT(20)
+
+#define AST2600_I2CS_ADDR_MASK GENMASK(19, 18)
+#define AST2600_I2CS_PKT_ERROR BIT(17)
+#define AST2600_I2CS_PKT_DONE BIT(16)
+#define AST2600_I2CS_INACTIVE_TO BIT(15)
+
+#define AST2600_I2CS_SLAVE_MATCH BIT(7)
+#define AST2600_I2CS_ABNOR_STOP BIT(5)
+#define AST2600_I2CS_STOP BIT(4)
+#define AST2600_I2CS_RX_DONE_NAK BIT(3)
+#define AST2600_I2CS_RX_DONE BIT(2)
+#define AST2600_I2CS_TX_NAK BIT(1)
+#define AST2600_I2CS_TX_ACK BIT(0)
+
+/* 0x28 : I2CS Target CMD/Status Register */
+#define AST2600_I2CS_CMD_STS 0x28
+#define AST2600_I2CS_ACTIVE_ALL GENMASK(18, 17)
+#define AST2600_I2CS_PKT_MODE_EN BIT(16)
+#define AST2600_I2CS_AUTO_NAK_NOADDR BIT(15)
+#define AST2600_I2CS_AUTO_NAK_EN BIT(14)
+
+#define AST2600_I2CS_ALT_EN BIT(10)
+#define AST2600_I2CS_RX_DMA_EN BIT(9)
+#define AST2600_I2CS_TX_DMA_EN BIT(8)
+#define AST2600_I2CS_RX_BUFF_EN BIT(7)
+#define AST2600_I2CS_TX_BUFF_EN BIT(6)
+#define AST2600_I2CS_RX_CMD_LAST BIT(4)
+
+#define AST2600_I2CS_TX_CMD BIT(2)
+
+#define AST2600_I2CS_DMA_LEN 0x2C
+#define AST2600_I2CS_SET_RX_DMA_LEN(x) (((((x) - 1) & GENMASK(11, 0)) << 16) | BIT(31))
+#define AST2600_I2CS_SET_TX_DMA_LEN(x) ((((x) - 1) & GENMASK(11, 0)) | BIT(15))
+
+/* I2CM Controller DMA Tx Buffer Register */
+#define AST2600_I2CM_TX_DMA 0x30
+/* I2CM Controller DMA Rx Buffer Register */
+#define AST2600_I2CM_RX_DMA 0x34
+/* I2CS Target DMA Tx Buffer Register */
+#define AST2600_I2CS_TX_DMA 0x38
+/* I2CS Target DMA Rx Buffer Register */
+#define AST2600_I2CS_RX_DMA 0x3C
+
+#define AST2600_I2CS_ADDR_CTRL 0x40
+
+#define AST2600_I2CS_ADDR3_MASK GENMASK(22, 16)
+#define AST2600_I2CS_ADDR2_MASK GENMASK(14, 8)
+#define AST2600_I2CS_ADDR1_MASK GENMASK(6, 0)
+
+#define AST2600_I2CM_DMA_LEN_STS 0x48
+#define AST2600_I2CS_DMA_LEN_STS 0x4C
+
+#define AST2600_I2C_GET_TX_DMA_LEN(x) ((x) & GENMASK(12, 0))
+#define AST2600_I2C_GET_RX_DMA_LEN(x) (((x) & GENMASK(28, 16)) >> 16)
+
+/* 0x40 : Target Device Address Register */
+#define AST2600_I2CS_ADDR3_ENABLE BIT(23)
+#define AST2600_I2CS_ADDR3(x) ((x) << 16)
+#define AST2600_I2CS_ADDR2_ENABLE BIT(15)
+#define AST2600_I2CS_ADDR2(x) ((x) << 8)
+#define AST2600_I2CS_ADDR1_ENABLE BIT(7)
+#define AST2600_I2CS_ADDR1(x) (x)
+
+#define I2C_TARGET_MSG_BUF_SIZE 4096
+
+#define AST2600_I2C_DMA_SIZE 4096
+
+#define CONTROLLER_TRIGGER_LAST_STOP (AST2600_I2CM_RX_CMD_LAST | AST2600_I2CM_STOP_CMD)
+#define TARGET_TRIGGER_CMD (AST2600_I2CS_ACTIVE_ALL | AST2600_I2CS_PKT_MODE_EN)
+
+#define AST_I2C_TIMEOUT_CLK 0x1
+
+enum xfer_mode {
+ BYTE_MODE,
+ BUFF_MODE,
+ DMA_MODE,
+};
+
+struct ast2600_i2c_bus {
+ struct i2c_adapter adap;
+ struct device *dev;
+ void __iomem *reg_base;
+ struct regmap *global_regs;
+ struct clk *clk;
+ struct i2c_timings timing_info;
+ struct completion cmd_complete;
+ struct i2c_msg *msgs;
+ u8 *controller_dma_buf;
+ dma_addr_t controller_dma_addr;
+ u32 apb_clk;
+ u32 timeout;
+ int irq;
+ int cmd_err;
+ int msgs_index;
+ int msgs_count;
+ int controller_xfer_cnt;
+ size_t buf_index;
+ size_t buf_size;
+ enum xfer_mode mode;
+ bool dma_available;
+ bool multi_master;
+ /* Buffer mode */
+ void __iomem *buf_base;
+ int (*setup_tx)(u32 cmd, struct ast2600_i2c_bus *i2c_bus);
+ int (*setup_rx)(u32 cmd, struct ast2600_i2c_bus *i2c_bus);
+};
+
+static void ast2600_i2c_ac_timing_config(struct ast2600_i2c_bus *i2c_bus)
+{
+ unsigned long base_clk[16];
+ int baseclk_idx = 0;
+ int divisor = 0;
+ u32 clk_div_reg;
+ u32 scl_low;
+ u32 scl_high;
+ u32 data;
+
+ regmap_read(i2c_bus->global_regs, AST2600_I2CG_CLK_DIV_CTRL, &clk_div_reg);
+
+ for (int i = 0; i < ARRAY_SIZE(base_clk); i++) {
+ if (i == 0)
+ base_clk[i] = i2c_bus->apb_clk;
+ else if (i < 5)
+ base_clk[i] = (i2c_bus->apb_clk * 2) /
+ (((clk_div_reg >> ((i - 1) * 8)) & GENMASK(7, 0)) + 2);
+ else
+ base_clk[i] = base_clk[4] >> (i - 4);
+
+ if ((base_clk[i] / i2c_bus->timing_info.bus_freq_hz) <= 32) {
+ baseclk_idx = i;
+ divisor = DIV_ROUND_UP(base_clk[i], i2c_bus->timing_info.bus_freq_hz);
+ break;
+ }
+ }
+ baseclk_idx = min(baseclk_idx, 15);
+ divisor = min(divisor, 32);
+ scl_low = min(divisor * 9 / 16 - 1, 15);
+ scl_high = (divisor - scl_low - 2) & GENMASK(3, 0);
+ data = (scl_high - 1) << 20 | scl_high << 16 | scl_low << 12 | baseclk_idx;
+ if (i2c_bus->timeout) {
+ data |= AST2600_I2CC_TOUTBASECLK(AST_I2C_TIMEOUT_CLK);
+ data |= AST2600_I2CC_TTIMEOUT(i2c_bus->timeout);
+ }
+
+ writel(data, i2c_bus->reg_base + AST2600_I2CC_AC_TIMING);
+}
+
+static int ast2600_i2c_recover_bus(struct ast2600_i2c_bus *i2c_bus)
+{
+ u32 state = readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF);
+ int ret = 0;
+ u32 ctrl;
+ int r;
+
+ dev_dbg(i2c_bus->dev, "%d-bus recovery bus [%x]\n", i2c_bus->adap.nr, state);
+
+ /* reset controller */
+ ctrl = readl(i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+ writel(ctrl & ~AST2600_I2CC_MASTER_EN, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+ writel(ctrl, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+
+ reinit_completion(&i2c_bus->cmd_complete);
+ i2c_bus->cmd_err = 0;
+
+ /* Check SDA/SCL status in the status register. */
+ state = readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF);
+ if (!(state & AST2600_I2CC_SDA_LINE_STS) && (state & AST2600_I2CC_SCL_LINE_STS)) {
+ writel(AST2600_I2CM_RECOVER_CMD_EN, i2c_bus->reg_base + AST2600_I2CM_CMD_STS);
+ r = wait_for_completion_timeout(&i2c_bus->cmd_complete, i2c_bus->adap.timeout);
+ if (r == 0) {
+ dev_dbg(i2c_bus->dev, "recovery timed out\n");
+ return -ETIMEDOUT;
+ } else if (i2c_bus->cmd_err) {
+ dev_dbg(i2c_bus->dev, "recovery error\n");
+ ret = -EPROTO;
+ }
+ }
+
+ /* Recovery done */
+ state = readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF);
+ if (state & AST2600_I2CC_BUS_BUSY_STS) {
+ dev_dbg(i2c_bus->dev, "Can't recover bus [%x]\n", state);
+ ret = -EPROTO;
+ }
+
+ return ret;
+}
+
+static int ast2600_i2c_setup_dma_tx(u32 cmd, struct ast2600_i2c_bus *i2c_bus)
+{
+ struct i2c_msg *msg = &i2c_bus->msgs[i2c_bus->msgs_index];
+ int xfer_len = msg->len - i2c_bus->controller_xfer_cnt;
+
+ cmd |= AST2600_I2CM_PKT_EN;
+
+ if (xfer_len > AST2600_I2C_DMA_SIZE)
+ xfer_len = AST2600_I2C_DMA_SIZE;
+ else if (i2c_bus->msgs_index + 1 == i2c_bus->msgs_count)
+ cmd |= AST2600_I2CM_STOP_CMD;
+
+ if (cmd & AST2600_I2CM_START_CMD)
+ cmd |= AST2600_I2CM_PKT_ADDR(msg->addr);
+
+ if (xfer_len) {
+ memcpy(i2c_bus->controller_dma_buf,
+ msg->buf + i2c_bus->controller_xfer_cnt, xfer_len);
+ cmd |= AST2600_I2CM_TX_DMA_EN | AST2600_I2CM_TX_CMD;
+ writel(AST2600_I2CM_SET_TX_DMA_LEN(xfer_len - 1),
+ i2c_bus->reg_base + AST2600_I2CM_DMA_LEN);
+ }
+
+ writel(cmd, i2c_bus->reg_base + AST2600_I2CM_CMD_STS);
+
+ return 0;
+}
+
+static int ast2600_i2c_setup_buff_tx(u32 cmd, struct ast2600_i2c_bus *i2c_bus)
+{
+ struct i2c_msg *msg = &i2c_bus->msgs[i2c_bus->msgs_index];
+ int xfer_len = msg->len - i2c_bus->controller_xfer_cnt;
+ u32 wbuf_dword;
+ int i;
+
+ cmd |= AST2600_I2CM_PKT_EN;
+
+ if (xfer_len > i2c_bus->buf_size)
+ xfer_len = i2c_bus->buf_size;
+ else if (i2c_bus->msgs_index + 1 == i2c_bus->msgs_count)
+ cmd |= AST2600_I2CM_STOP_CMD;
+
+ if (cmd & AST2600_I2CM_START_CMD)
+ cmd |= AST2600_I2CM_PKT_ADDR(msg->addr);
+
+ if (xfer_len) {
+ cmd |= AST2600_I2CM_TX_BUFF_EN | AST2600_I2CM_TX_CMD;
+ /*
+ * The controller's buffer register supports dword writes only.
+ * Therefore, write dwords to the buffer register in a 4-byte aligned,
+ * and write the remaining unaligned data at the end.
+ */
+ for (i = 0; i < xfer_len; i += 4) {
+ int xfer_cnt = i2c_bus->controller_xfer_cnt + i;
+
+ switch (min(xfer_len - i, 4) % 4) {
+ case 1:
+ wbuf_dword = msg->buf[xfer_cnt];
+ break;
+ case 2:
+ wbuf_dword = get_unaligned_le16(&msg->buf[xfer_cnt]);
+ break;
+ case 3:
+ wbuf_dword = get_unaligned_le24(&msg->buf[xfer_cnt]);
+ break;
+ default:
+ wbuf_dword = get_unaligned_le32(&msg->buf[xfer_cnt]);
+ break;
+ }
+ writel(wbuf_dword, i2c_bus->buf_base + i);
+ }
+ writel(AST2600_I2CC_SET_TX_BUF_LEN(xfer_len),
+ i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL);
+ }
+
+ writel(cmd, i2c_bus->reg_base + AST2600_I2CM_CMD_STS);
+
+ return 0;
+}
+
+static int ast2600_i2c_setup_byte_tx(u32 cmd, struct ast2600_i2c_bus *i2c_bus)
+{
+ struct i2c_msg *msg = &i2c_bus->msgs[i2c_bus->msgs_index];
+ int xfer_len;
+
+ xfer_len = msg->len - i2c_bus->controller_xfer_cnt;
+
+ cmd |= AST2600_I2CM_PKT_EN;
+
+ if (cmd & AST2600_I2CM_START_CMD)
+ cmd |= AST2600_I2CM_PKT_ADDR(msg->addr);
+
+ if ((i2c_bus->msgs_index + 1 == i2c_bus->msgs_count) &&
+ ((i2c_bus->controller_xfer_cnt + 1) == msg->len))
+ cmd |= AST2600_I2CM_STOP_CMD;
+
+ if (xfer_len) {
+ cmd |= AST2600_I2CM_TX_CMD;
+ writel(msg->buf[i2c_bus->controller_xfer_cnt],
+ i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF);
+ }
+
+ writel(cmd, i2c_bus->reg_base + AST2600_I2CM_CMD_STS);
+
+ return 0;
+}
+
+static int ast2600_i2c_setup_dma_rx(u32 cmd, struct ast2600_i2c_bus *i2c_bus)
+{
+ struct i2c_msg *msg = &i2c_bus->msgs[i2c_bus->msgs_index];
+ int xfer_len = msg->len - i2c_bus->controller_xfer_cnt;
+
+ cmd |= AST2600_I2CM_PKT_EN | AST2600_I2CM_RX_DMA_EN | AST2600_I2CM_RX_CMD;
+
+ if (msg->flags & I2C_M_RECV_LEN)
+ xfer_len = 1;
+ else if (xfer_len > AST2600_I2C_DMA_SIZE)
+ xfer_len = AST2600_I2C_DMA_SIZE;
+ else if (i2c_bus->msgs_index + 1 == i2c_bus->msgs_count)
+ cmd |= CONTROLLER_TRIGGER_LAST_STOP;
+
+ writel(AST2600_I2CM_SET_RX_DMA_LEN(xfer_len - 1), i2c_bus->reg_base + AST2600_I2CM_DMA_LEN);
+
+ if (cmd & AST2600_I2CM_START_CMD)
+ cmd |= AST2600_I2CM_PKT_ADDR(msg->addr);
+
+ writel(cmd, i2c_bus->reg_base + AST2600_I2CM_CMD_STS);
+
+ return 0;
+}
+
+static int ast2600_i2c_setup_buff_rx(u32 cmd, struct ast2600_i2c_bus *i2c_bus)
+{
+ struct i2c_msg *msg = &i2c_bus->msgs[i2c_bus->msgs_index];
+ int xfer_len = msg->len - i2c_bus->controller_xfer_cnt;
+
+ cmd |= AST2600_I2CM_PKT_EN | AST2600_I2CM_RX_BUFF_EN | AST2600_I2CM_RX_CMD;
+
+ if (cmd & AST2600_I2CM_START_CMD)
+ cmd |= AST2600_I2CM_PKT_ADDR(msg->addr);
+
+ if (msg->flags & I2C_M_RECV_LEN) {
+ dev_dbg(i2c_bus->dev, "smbus read\n");
+ xfer_len = 1;
+ } else if (xfer_len > i2c_bus->buf_size) {
+ xfer_len = i2c_bus->buf_size;
+ } else if (i2c_bus->msgs_index + 1 == i2c_bus->msgs_count) {
+ cmd |= CONTROLLER_TRIGGER_LAST_STOP;
+ }
+ writel(AST2600_I2CC_SET_RX_BUF_LEN(xfer_len), i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL);
+
+ writel(cmd, i2c_bus->reg_base + AST2600_I2CM_CMD_STS);
+
+ return 0;
+}
+
+static int ast2600_i2c_setup_byte_rx(u32 cmd, struct ast2600_i2c_bus *i2c_bus)
+{
+ struct i2c_msg *msg = &i2c_bus->msgs[i2c_bus->msgs_index];
+
+ cmd |= AST2600_I2CM_PKT_EN | AST2600_I2CM_RX_CMD;
+
+ if (cmd & AST2600_I2CM_START_CMD)
+ cmd |= AST2600_I2CM_PKT_ADDR(msg->addr);
+
+ if (msg->flags & I2C_M_RECV_LEN) {
+ dev_dbg(i2c_bus->dev, "smbus read\n");
+ } else if ((i2c_bus->msgs_index + 1 == i2c_bus->msgs_count) &&
+ ((i2c_bus->controller_xfer_cnt + 1) == msg->len)) {
+ cmd |= CONTROLLER_TRIGGER_LAST_STOP;
+ }
+
+ writel(cmd, i2c_bus->reg_base + AST2600_I2CM_CMD_STS);
+
+ return 0;
+}
+
+static int ast2600_i2c_do_start(struct ast2600_i2c_bus *i2c_bus)
+{
+ struct i2c_msg *msg = &i2c_bus->msgs[i2c_bus->msgs_index];
+
+ /* send start */
+ dev_dbg(i2c_bus->dev, "[%d] %s %d byte%s %s 0x%02x\n",
+ i2c_bus->msgs_index, str_read_write(msg->flags & I2C_M_RD),
+ msg->len, str_plural(msg->len),
+ msg->flags & I2C_M_RD ? "from" : "to", msg->addr);
+
+ if (!i2c_bus->setup_rx || !i2c_bus->setup_tx)
+ return -EINVAL;
+
+ i2c_bus->controller_xfer_cnt = 0;
+ i2c_bus->buf_index = 0;
+
+ if (msg->flags & I2C_M_RD)
+ return i2c_bus->setup_rx(AST2600_I2CM_START_CMD, i2c_bus);
+
+ return i2c_bus->setup_tx(AST2600_I2CM_START_CMD, i2c_bus);
+}
+
+static int ast2600_i2c_irq_err_to_errno(u32 irq_status)
+{
+ if (irq_status & AST2600_I2CM_ARBIT_LOSS)
+ return -EAGAIN;
+ if (irq_status & (AST2600_I2CM_SDA_DL_TO | AST2600_I2CM_SCL_LOW_TO))
+ return -ETIMEDOUT;
+ if (irq_status & (AST2600_I2CM_ABNORMAL))
+ return -EPROTO;
+
+ return 0;
+}
+
+static void ast2600_i2c_controller_packet_irq(struct ast2600_i2c_bus *i2c_bus, u32 sts)
+{
+ struct i2c_msg *msg = &i2c_bus->msgs[i2c_bus->msgs_index];
+ int xfer_len;
+ int i;
+
+ sts &= ~AST2600_I2CM_PKT_DONE;
+ writel(AST2600_I2CM_PKT_DONE, i2c_bus->reg_base + AST2600_I2CM_ISR);
+ switch (sts) {
+ case AST2600_I2CM_PKT_ERROR:
+ i2c_bus->cmd_err = -EAGAIN;
+ complete(&i2c_bus->cmd_complete);
+ break;
+ case AST2600_I2CM_PKT_ERROR | AST2600_I2CM_TX_NAK: /* a0 fix for issue */
+ fallthrough;
+ case AST2600_I2CM_PKT_ERROR | AST2600_I2CM_TX_NAK | AST2600_I2CM_NORMAL_STOP:
+ i2c_bus->cmd_err = -ENXIO;
+ complete(&i2c_bus->cmd_complete);
+ break;
+ case AST2600_I2CM_NORMAL_STOP:
+ /* write 0 byte only have stop isr */
+ i2c_bus->msgs_index++;
+ if (i2c_bus->msgs_index < i2c_bus->msgs_count) {
+ if (ast2600_i2c_do_start(i2c_bus)) {
+ i2c_bus->cmd_err = -ENOMEM;
+ complete(&i2c_bus->cmd_complete);
+ }
+ } else {
+ i2c_bus->cmd_err = i2c_bus->msgs_index;
+ complete(&i2c_bus->cmd_complete);
+ }
+ break;
+ case AST2600_I2CM_TX_ACK:
+ case AST2600_I2CM_TX_ACK | AST2600_I2CM_NORMAL_STOP:
+ if (i2c_bus->mode == DMA_MODE)
+ xfer_len = AST2600_I2C_GET_TX_DMA_LEN(readl(i2c_bus->reg_base +
+ AST2600_I2CM_DMA_LEN_STS));
+ else if (i2c_bus->mode == BUFF_MODE)
+ xfer_len = AST2600_I2CC_GET_TX_BUF_LEN(readl(i2c_bus->reg_base +
+ AST2600_I2CC_BUFF_CTRL));
+ else
+ xfer_len = 1;
+
+ i2c_bus->controller_xfer_cnt += xfer_len;
+
+ if (i2c_bus->controller_xfer_cnt == msg->len) {
+ i2c_bus->msgs_index++;
+ if (i2c_bus->msgs_index == i2c_bus->msgs_count) {
+ i2c_bus->cmd_err = i2c_bus->msgs_index;
+ complete(&i2c_bus->cmd_complete);
+ } else {
+ if (ast2600_i2c_do_start(i2c_bus)) {
+ i2c_bus->cmd_err = -ENOMEM;
+ complete(&i2c_bus->cmd_complete);
+ }
+ }
+ } else {
+ i2c_bus->setup_tx(0, i2c_bus);
+ }
+ break;
+ case AST2600_I2CM_RX_DONE:
+ case AST2600_I2CM_RX_DONE | AST2600_I2CM_NORMAL_STOP:
+ /* do next rx */
+ if (i2c_bus->mode == DMA_MODE) {
+ xfer_len = AST2600_I2C_GET_RX_DMA_LEN(readl(i2c_bus->reg_base +
+ AST2600_I2CM_DMA_LEN_STS));
+ memcpy(&msg->buf[i2c_bus->controller_xfer_cnt],
+ i2c_bus->controller_dma_buf, xfer_len);
+ } else if (i2c_bus->mode == BUFF_MODE) {
+ xfer_len = AST2600_I2CC_GET_RX_BUF_LEN(readl(i2c_bus->reg_base +
+ AST2600_I2CC_BUFF_CTRL));
+ for (i = 0; i < xfer_len; i++)
+ msg->buf[i2c_bus->controller_xfer_cnt + i] =
+ readb(i2c_bus->buf_base + 0x10 + i);
+ } else {
+ xfer_len = 1;
+ msg->buf[i2c_bus->controller_xfer_cnt] =
+ AST2600_I2CC_GET_RX_BUFF(readl(i2c_bus->reg_base +
+ AST2600_I2CC_STS_AND_BUFF));
+ }
+
+ if (msg->flags & I2C_M_RECV_LEN) {
+ u8 recv_len = AST2600_I2CC_GET_RX_BUFF(readl(i2c_bus->reg_base
+ + AST2600_I2CC_STS_AND_BUFF));
+ msg->len = min_t(unsigned int, recv_len, I2C_SMBUS_BLOCK_MAX);
+ msg->len += ((msg->flags & I2C_CLIENT_PEC) ? 2 : 1);
+ msg->flags &= ~I2C_M_RECV_LEN;
+ if (!recv_len)
+ i2c_bus->controller_xfer_cnt = 0;
+ else
+ i2c_bus->controller_xfer_cnt = 1;
+ } else {
+ i2c_bus->controller_xfer_cnt += xfer_len;
+ }
+
+ if (i2c_bus->controller_xfer_cnt == msg->len) {
+ i2c_bus->msgs_index++;
+ if (i2c_bus->msgs_index == i2c_bus->msgs_count) {
+ i2c_bus->cmd_err = i2c_bus->msgs_index;
+ complete(&i2c_bus->cmd_complete);
+ } else {
+ if (ast2600_i2c_do_start(i2c_bus)) {
+ i2c_bus->cmd_err = -ENOMEM;
+ complete(&i2c_bus->cmd_complete);
+ }
+ }
+ } else {
+ i2c_bus->setup_rx(0, i2c_bus);
+ }
+ break;
+ default:
+ dev_dbg(i2c_bus->dev, "unhandled sts %x\n", sts);
+ break;
+ }
+}
+
+static int ast2600_i2c_controller_irq(struct ast2600_i2c_bus *i2c_bus)
+{
+ u32 sts = readl(i2c_bus->reg_base + AST2600_I2CM_ISR);
+ u32 ctrl;
+
+ sts &= ~AST2600_I2CM_SMBUS_ALERT;
+
+ if (sts & AST2600_I2CM_BUS_RECOVER_FAIL) {
+ writel(AST2600_I2CM_BUS_RECOVER_FAIL, i2c_bus->reg_base + AST2600_I2CM_ISR);
+ ctrl = readl(i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+ writel(0, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+ writel(ctrl, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+ i2c_bus->cmd_err = -EPROTO;
+ complete(&i2c_bus->cmd_complete);
+ return 1;
+ }
+
+ if (sts & AST2600_I2CM_BUS_RECOVER) {
+ writel(AST2600_I2CM_BUS_RECOVER, i2c_bus->reg_base + AST2600_I2CM_ISR);
+ i2c_bus->cmd_err = 0;
+ complete(&i2c_bus->cmd_complete);
+ return 1;
+ }
+
+ i2c_bus->cmd_err = ast2600_i2c_irq_err_to_errno(sts);
+ if (i2c_bus->cmd_err) {
+ writel(AST2600_I2CM_PKT_DONE, i2c_bus->reg_base + AST2600_I2CM_ISR);
+ complete(&i2c_bus->cmd_complete);
+ return 1;
+ }
+
+ if (sts & AST2600_I2CM_PKT_DONE) {
+ ast2600_i2c_controller_packet_irq(i2c_bus, sts);
+ return 1;
+ }
+
+ return 0;
+}
+
+static irqreturn_t ast2600_i2c_bus_irq(int irq, void *dev_id)
+{
+ struct ast2600_i2c_bus *i2c_bus = dev_id;
+
+ return IRQ_RETVAL(ast2600_i2c_controller_irq(i2c_bus));
+}
+
+static int ast2600_i2c_controller_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
+{
+ struct ast2600_i2c_bus *i2c_bus = i2c_get_adapdata(adap);
+ unsigned long timeout;
+ int ret;
+
+ if (!i2c_bus->multi_master &&
+ (readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF) & AST2600_I2CC_BUS_BUSY_STS)) {
+ ret = ast2600_i2c_recover_bus(i2c_bus);
+ if (ret)
+ return ret;
+ }
+
+ i2c_bus->cmd_err = 0;
+ i2c_bus->msgs = msgs;
+ i2c_bus->msgs_index = 0;
+ i2c_bus->msgs_count = num;
+ reinit_completion(&i2c_bus->cmd_complete);
+ ret = ast2600_i2c_do_start(i2c_bus);
+ if (ret)
+ goto controller_out;
+ timeout = wait_for_completion_timeout(&i2c_bus->cmd_complete, i2c_bus->adap.timeout);
+ if (timeout == 0) {
+ u32 ctrl = readl(i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+
+ dev_dbg(i2c_bus->dev, "timeout isr[%x], sts[%x]\n",
+ readl(i2c_bus->reg_base + AST2600_I2CM_ISR),
+ readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF));
+ writel(ctrl & ~AST2600_I2CC_MASTER_EN, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+ writel(ctrl, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+
+ /*
+ * A slave holding SCL low can stall the transfer and trigger
+ * a master timeout. In multi-master mode, attempt bus recovery
+ * if the bus is still busy.
+ */
+ if (i2c_bus->multi_master &&
+ (readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF) &
+ AST2600_I2CC_BUS_BUSY_STS))
+ ast2600_i2c_recover_bus(i2c_bus);
+ ret = -ETIMEDOUT;
+ } else {
+ ret = i2c_bus->cmd_err;
+ }
+
+ dev_dbg(i2c_bus->dev, "bus%d-m: %d end\n", i2c_bus->adap.nr, i2c_bus->cmd_err);
+
+controller_out:
+ return ret;
+}
+
+static int ast2600_i2c_init(struct ast2600_i2c_bus *i2c_bus)
+{
+ u32 fun_ctrl = AST2600_I2CC_BUS_AUTO_RELEASE | AST2600_I2CC_MASTER_EN;
+
+ /* I2C Reset */
+ writel(0, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+
+ if (!i2c_bus->multi_master)
+ fun_ctrl |= AST2600_I2CC_MULTI_MASTER_DIS;
+
+ /* Enable Controller Mode */
+ writel(fun_ctrl, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+ /* disable target address */
+ writel(0, i2c_bus->reg_base + AST2600_I2CS_ADDR_CTRL);
+
+ /* Set AC Timing */
+ ast2600_i2c_ac_timing_config(i2c_bus);
+
+ if (i2c_bus->dma_available) {
+ i2c_bus->controller_dma_buf =
+ dmam_alloc_coherent(i2c_bus->dev, AST2600_I2C_DMA_SIZE,
+ &i2c_bus->controller_dma_addr, GFP_KERNEL);
+ if (!i2c_bus->controller_dma_buf)
+ return -ENOMEM;
+ writel(i2c_bus->controller_dma_addr,
+ i2c_bus->reg_base + AST2600_I2CM_TX_DMA);
+ writel(i2c_bus->controller_dma_addr,
+ i2c_bus->reg_base + AST2600_I2CM_RX_DMA);
+ }
+
+ /* Clear Interrupt */
+ writel(GENMASK(27, 0), i2c_bus->reg_base + AST2600_I2CM_ISR);
+
+ return 0;
+}
+
+static u32 ast2600_i2c_functionality(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_SMBUS_BLOCK_DATA;
+}
+
+static const struct i2c_algorithm i2c_ast2600_algorithm = {
+ .xfer = ast2600_i2c_controller_xfer,
+ .functionality = ast2600_i2c_functionality,
+};
+
+static void ast2600_i2c_set_xfer_mode(struct ast2600_i2c_bus *i2c_bus,
+ enum xfer_mode mode)
+{
+ i2c_bus->mode = mode;
+
+ switch (mode) {
+ case DMA_MODE:
+ i2c_bus->setup_tx = ast2600_i2c_setup_dma_tx;
+ i2c_bus->setup_rx = ast2600_i2c_setup_dma_rx;
+ break;
+ case BYTE_MODE:
+ i2c_bus->setup_tx = ast2600_i2c_setup_byte_tx;
+ i2c_bus->setup_rx = ast2600_i2c_setup_byte_rx;
+ break;
+ case BUFF_MODE:
+ default:
+ i2c_bus->setup_tx = ast2600_i2c_setup_buff_tx;
+ i2c_bus->setup_rx = ast2600_i2c_setup_buff_rx;
+ break;
+ }
+}
+
+static int ast2600_i2c_xfer_mode_parse(const char *buf, enum xfer_mode *mode)
+{
+ if (sysfs_streq(buf, "byte")) {
+ *mode = BYTE_MODE;
+ return 0;
+ }
+
+ if (sysfs_streq(buf, "buffer")) {
+ *mode = BUFF_MODE;
+ return 0;
+ }
+
+ if (sysfs_streq(buf, "dma")) {
+ *mode = DMA_MODE;
+ return 0;
+ }
+
+ return -EINVAL;
+}
+
+static int ast2600_i2c_xfer_mode_check(struct ast2600_i2c_bus *i2c_bus,
+ enum xfer_mode mode)
+{
+ if (mode == BUFF_MODE && !i2c_bus->buf_base)
+ return -EINVAL;
+ if (mode == DMA_MODE && !i2c_bus->dma_available)
+ return -EINVAL;
+ return 0;
+}
+
+static const char *ast2600_i2c_xfer_mode_name(enum xfer_mode mode)
+{
+ switch (mode) {
+ case BYTE_MODE:
+ return "byte";
+ case DMA_MODE:
+ return "dma";
+ case BUFF_MODE:
+ default:
+ return "buffer";
+ }
+}
+
+static ssize_t xfer_mode_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct ast2600_i2c_bus *i2c_bus = dev_get_drvdata(dev);
+
+ return sysfs_emit(buf, "%s\n", ast2600_i2c_xfer_mode_name(i2c_bus->mode));
+}
+
+static ssize_t xfer_mode_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct ast2600_i2c_bus *i2c_bus = dev_get_drvdata(dev);
+ enum xfer_mode mode;
+ int ret;
+
+ ret = ast2600_i2c_xfer_mode_parse(buf, &mode);
+ if (ret)
+ return ret;
+
+ ret = ast2600_i2c_xfer_mode_check(i2c_bus, mode);
+ if (ret)
+ return ret;
+
+ i2c_lock_bus(&i2c_bus->adap, I2C_LOCK_ROOT_ADAPTER);
+ ast2600_i2c_set_xfer_mode(i2c_bus, mode);
+ i2c_unlock_bus(&i2c_bus->adap, I2C_LOCK_ROOT_ADAPTER);
+
+ return count;
+}
+
+static DEVICE_ATTR_RW(xfer_mode);
+
+static int ast2600_i2c_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct ast2600_i2c_bus *i2c_bus;
+ void __iomem *buf_base;
+ struct reset_control *rst;
+ struct resource *res;
+ u32 global_ctrl;
+ int ret;
+
+ if (!device_property_present(dev, "aspeed,global-regs"))
+ return -ENODEV;
+
+ i2c_bus = devm_kzalloc(dev, sizeof(*i2c_bus), GFP_KERNEL);
+ if (!i2c_bus)
+ return -ENOMEM;
+
+ i2c_bus->reg_base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(i2c_bus->reg_base))
+ return PTR_ERR(i2c_bus->reg_base);
+
+ rst = devm_reset_control_get_shared_deasserted(dev, NULL);
+ if (IS_ERR(rst))
+ return dev_err_probe(dev, PTR_ERR(rst), "Missing reset ctrl\n");
+
+ i2c_bus->global_regs =
+ syscon_regmap_lookup_by_phandle(dev_of_node(dev), "aspeed,global-regs");
+ if (IS_ERR(i2c_bus->global_regs))
+ return PTR_ERR(i2c_bus->global_regs);
+
+ regmap_read(i2c_bus->global_regs, AST2600_I2CG_CTRL, &global_ctrl);
+ if ((global_ctrl & AST2600_GLOBAL_INIT) != AST2600_GLOBAL_INIT) {
+ regmap_write(i2c_bus->global_regs, AST2600_I2CG_CTRL, AST2600_GLOBAL_INIT);
+ regmap_write(i2c_bus->global_regs, AST2600_I2CG_CLK_DIV_CTRL, I2CCG_DIV_CTRL);
+ }
+
+ i2c_bus->dev = dev;
+ i2c_bus->multi_master = device_property_read_bool(dev, "multi-master");
+ i2c_bus->dma_available = device_property_read_bool(dev, "aspeed,enable-dma");
+
+ buf_base = devm_platform_get_and_ioremap_resource(pdev, 1, &res);
+ if (!IS_ERR(buf_base)) {
+ i2c_bus->buf_base = buf_base;
+ i2c_bus->buf_size = resource_size(res) / 2;
+ }
+
+ enum xfer_mode mode;
+
+ if (i2c_bus->dma_available)
+ mode = DMA_MODE;
+ else if (i2c_bus->buf_base)
+ mode = BUFF_MODE;
+ else
+ mode = BYTE_MODE;
+
+ ast2600_i2c_set_xfer_mode(i2c_bus, mode);
+
+ /*
+ * i2c timeout counter: use base clk4 1Mhz,
+ * per unit: 1/(1000/1024) = 1024us
+ */
+ ret = device_property_read_u32(dev, "i2c-scl-clk-low-timeout-us", &i2c_bus->timeout);
+ if (!ret)
+ i2c_bus->timeout = DIV_ROUND_UP(i2c_bus->timeout, 1024);
+
+ init_completion(&i2c_bus->cmd_complete);
+
+ i2c_bus->irq = platform_get_irq(pdev, 0);
+ if (i2c_bus->irq < 0)
+ return i2c_bus->irq;
+
+ platform_set_drvdata(pdev, i2c_bus);
+
+ i2c_bus->clk = devm_clk_get(i2c_bus->dev, NULL);
+ if (IS_ERR(i2c_bus->clk))
+ return dev_err_probe(i2c_bus->dev, PTR_ERR(i2c_bus->clk), "Can't get clock\n");
+
+ i2c_bus->apb_clk = clk_get_rate(i2c_bus->clk);
+
+ i2c_parse_fw_timings(i2c_bus->dev, &i2c_bus->timing_info, true);
+
+ /* Initialize the I2C adapter */
+ i2c_bus->adap.owner = THIS_MODULE;
+ i2c_bus->adap.algo = &i2c_ast2600_algorithm;
+ i2c_bus->adap.retries = 0;
+ i2c_bus->adap.dev.parent = i2c_bus->dev;
+ device_set_node(&i2c_bus->adap.dev, dev_fwnode(dev));
+ i2c_bus->adap.algo_data = i2c_bus;
+ strscpy(i2c_bus->adap.name, pdev->name);
+ i2c_set_adapdata(&i2c_bus->adap, i2c_bus);
+
+ ret = ast2600_i2c_init(i2c_bus);
+ if (ret < 0)
+ return dev_err_probe(dev, ret, "Unable to initialize i2c %d\n", ret);
+
+ ret = devm_request_irq(dev, i2c_bus->irq, ast2600_i2c_bus_irq, 0,
+ dev_name(dev), i2c_bus);
+ if (ret < 0) {
+ ret = dev_err_probe(dev, ret, "Unable to request irq %d\n",
+ i2c_bus->irq);
+ goto err;
+ }
+
+ writel(AST2600_I2CM_PKT_DONE | AST2600_I2CM_BUS_RECOVER,
+ i2c_bus->reg_base + AST2600_I2CM_IER);
+
+ ret = sysfs_create_file(&dev->kobj, &dev_attr_xfer_mode.attr);
+ if (ret)
+ goto err;
+
+ ret = devm_i2c_add_adapter(dev, &i2c_bus->adap);
+ if (ret) {
+ sysfs_remove_file(&dev->kobj, &dev_attr_xfer_mode.attr);
+ goto err;
+ }
+
+ return 0;
+
+err:
+ writel(0, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+ writel(0, i2c_bus->reg_base + AST2600_I2CM_IER);
+ return ret;
+}
+
+static void ast2600_i2c_remove(struct platform_device *pdev)
+{
+ struct ast2600_i2c_bus *i2c_bus = platform_get_drvdata(pdev);
+
+ sysfs_remove_file(&pdev->dev.kobj, &dev_attr_xfer_mode.attr);
+
+ /* Disable everything. */
+ writel(0, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+ writel(0, i2c_bus->reg_base + AST2600_I2CM_IER);
+}
+
+static const struct of_device_id ast2600_i2c_of_match[] = {
+ { .compatible = "aspeed,ast2600-i2c-bus" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, ast2600_i2c_of_match);
+
+static struct platform_driver ast2600_i2c_driver = {
+ .probe = ast2600_i2c_probe,
+ .remove = ast2600_i2c_remove,
+ .driver = {
+ .name = "ast2600-i2c",
+ .of_match_table = ast2600_i2c_of_match,
+ },
+};
+module_platform_driver(ast2600_i2c_driver);
+
+MODULE_AUTHOR("Ryan Chen <ryan_chen@aspeedtech.com>");
+MODULE_DESCRIPTION("ASPEED AST2600 I2C Controller Driver");
+MODULE_LICENSE("GPL");
--
2.34.1
^ permalink raw reply related [flat|nested] 11+ messages in thread* [PATCH v28 4/4] i2c: ast2600: Add target mode support
2026-03-30 8:21 [PATCH v28 0/4] Add ASPEED AST2600 I2C controller driver Ryan Chen
` (2 preceding siblings ...)
2026-03-30 8:21 ` [PATCH v28 3/4] i2c: ast2600: Add controller driver for AST2600 new register set Ryan Chen
@ 2026-03-30 8:21 ` Ryan Chen
3 siblings, 0 replies; 11+ messages in thread
From: Ryan Chen @ 2026-03-30 8:21 UTC (permalink / raw)
To: jk, andriy.shevchenko, Andi Shyti, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Joel Stanley, Andrew Jeffery,
Benjamin Herrenschmidt, Rayn Chen, Philipp Zabel
Cc: linux-i2c, devicetree, linux-arm-kernel, linux-aspeed,
linux-kernel, openbmc, Ryan Chen
Add target mode support to the AST2600 I2C driver.
Target mode features implemented include:
- Add target interrupt handling
- Address match and response logic
- Separate Tx/Rx DMA address and length configuration
This complements the existing controller-mode support, enabling
dual-role capability.
Signed-off-by: Ryan Chen <ryan_chen@aspeedtech.com>
---
Changes in v28:
- fix typo condication -> condition
- fix compile error, when disable CONFIG_I2C_SLAVE
Changes in v26:
- change int to bool target_operate
- rename target_operate to target_active
- use i2c_bus->target replace require IO
- use WRITE_ONCE replace target_operate write.
---
drivers/i2c/busses/i2c-ast2600.c | 566 +++++++++++++++++++++++++++++++++++++++
1 file changed, 566 insertions(+)
diff --git a/drivers/i2c/busses/i2c-ast2600.c b/drivers/i2c/busses/i2c-ast2600.c
index c2368ba309a7..a9b77917a1fe 100644
--- a/drivers/i2c/busses/i2c-ast2600.c
+++ b/drivers/i2c/busses/i2c-ast2600.c
@@ -274,6 +274,13 @@ struct ast2600_i2c_bus {
void __iomem *buf_base;
int (*setup_tx)(u32 cmd, struct ast2600_i2c_bus *i2c_bus);
int (*setup_rx)(u32 cmd, struct ast2600_i2c_bus *i2c_bus);
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ /* target structure */
+ bool target_active;
+ unsigned char *target_dma_buf;
+ dma_addr_t target_dma_addr;
+ struct i2c_client *target;
+#endif
};
static void ast2600_i2c_ac_timing_config(struct ast2600_i2c_bus *i2c_bus)
@@ -357,6 +364,440 @@ static int ast2600_i2c_recover_bus(struct ast2600_i2c_bus *i2c_bus)
return ret;
}
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+static void ast2600_i2c_target_packet_dma_irq(struct ast2600_i2c_bus *i2c_bus, u32 sts)
+{
+ int target_rx_len = 0;
+ u32 cmd = 0;
+ u8 value;
+ int i;
+
+ sts &= ~(AST2600_I2CS_SLAVE_PENDING);
+ /* Handle i2c target timeout condition */
+ if (sts & AST2600_I2CS_INACTIVE_TO) {
+ /* Reset timeout counter */
+ u32 ac_timing = readl(i2c_bus->reg_base + AST2600_I2CC_AC_TIMING) &
+ AST2600_I2CC_AC_TIMING_MASK;
+
+ writel(ac_timing, i2c_bus->reg_base + AST2600_I2CC_AC_TIMING);
+ ac_timing |= AST2600_I2CC_TTIMEOUT(i2c_bus->timeout);
+ writel(ac_timing, i2c_bus->reg_base + AST2600_I2CC_AC_TIMING);
+ cmd = TARGET_TRIGGER_CMD | AST2600_I2CS_RX_DMA_EN;
+ writel(AST2600_I2CS_SET_RX_DMA_LEN(I2C_TARGET_MSG_BUF_SIZE),
+ i2c_bus->reg_base + AST2600_I2CS_DMA_LEN);
+ writel(cmd, i2c_bus->reg_base + AST2600_I2CS_CMD_STS);
+ writel(AST2600_I2CS_PKT_DONE, i2c_bus->reg_base + AST2600_I2CS_ISR);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_STOP, &value);
+ return;
+ }
+
+ sts &= ~(AST2600_I2CS_PKT_DONE | AST2600_I2CS_PKT_ERROR);
+
+ switch (sts) {
+ case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE | AST2600_I2CS_WAIT_RX_DMA:
+ case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_WAIT_RX_DMA:
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_REQUESTED, &value);
+ target_rx_len = AST2600_I2C_GET_RX_DMA_LEN(readl(i2c_bus->reg_base +
+ AST2600_I2CS_DMA_LEN_STS));
+ for (i = 0; i < target_rx_len; i++) {
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_RECEIVED,
+ &i2c_bus->target_dma_buf[i]);
+ }
+ writel(AST2600_I2CS_SET_RX_DMA_LEN(I2C_TARGET_MSG_BUF_SIZE),
+ i2c_bus->reg_base + AST2600_I2CS_DMA_LEN);
+ cmd = TARGET_TRIGGER_CMD | AST2600_I2CS_RX_DMA_EN;
+ break;
+ case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_STOP:
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_STOP, &value);
+ writel(AST2600_I2CS_SET_RX_DMA_LEN(I2C_TARGET_MSG_BUF_SIZE),
+ i2c_bus->reg_base + AST2600_I2CS_DMA_LEN);
+ cmd = TARGET_TRIGGER_CMD | AST2600_I2CS_RX_DMA_EN;
+ break;
+ case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE_NAK |
+ AST2600_I2CS_RX_DONE | AST2600_I2CS_STOP:
+ case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_WAIT_RX_DMA |
+ AST2600_I2CS_RX_DONE | AST2600_I2CS_STOP:
+ case AST2600_I2CS_RX_DONE_NAK | AST2600_I2CS_RX_DONE | AST2600_I2CS_STOP:
+ case AST2600_I2CS_RX_DONE | AST2600_I2CS_WAIT_RX_DMA | AST2600_I2CS_STOP:
+ case AST2600_I2CS_RX_DONE | AST2600_I2CS_STOP:
+ case AST2600_I2CS_RX_DONE | AST2600_I2CS_WAIT_RX_DMA:
+ case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE | AST2600_I2CS_STOP:
+ if (sts & AST2600_I2CS_SLAVE_MATCH)
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_REQUESTED, &value);
+
+ target_rx_len = AST2600_I2C_GET_RX_DMA_LEN(readl(i2c_bus->reg_base +
+ AST2600_I2CS_DMA_LEN_STS));
+ for (i = 0; i < target_rx_len; i++) {
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_RECEIVED,
+ &i2c_bus->target_dma_buf[i]);
+ }
+ writel(AST2600_I2CS_SET_RX_DMA_LEN(I2C_TARGET_MSG_BUF_SIZE),
+ i2c_bus->reg_base + AST2600_I2CS_DMA_LEN);
+ if (sts & AST2600_I2CS_STOP)
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_STOP, &value);
+ cmd = TARGET_TRIGGER_CMD | AST2600_I2CS_RX_DMA_EN;
+ break;
+
+ /* it is Mw data Mr coming -> it need send tx */
+ case AST2600_I2CS_RX_DONE | AST2600_I2CS_WAIT_TX_DMA:
+ case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE | AST2600_I2CS_WAIT_TX_DMA:
+ /* it should be repeat start read */
+ if (sts & AST2600_I2CS_SLAVE_MATCH)
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_REQUESTED, &value);
+
+ target_rx_len = AST2600_I2C_GET_RX_DMA_LEN(readl(i2c_bus->reg_base +
+ AST2600_I2CS_DMA_LEN_STS));
+ for (i = 0; i < target_rx_len; i++) {
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_RECEIVED,
+ &i2c_bus->target_dma_buf[i]);
+ }
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_READ_REQUESTED,
+ &i2c_bus->target_dma_buf[0]);
+ writel(AST2600_I2CS_SET_TX_DMA_LEN(1),
+ i2c_bus->reg_base + AST2600_I2CS_DMA_LEN);
+ cmd = TARGET_TRIGGER_CMD | AST2600_I2CS_TX_DMA_EN;
+ break;
+ case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_WAIT_TX_DMA:
+ /* First Start read */
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_READ_REQUESTED,
+ &i2c_bus->target_dma_buf[0]);
+ writel(AST2600_I2CS_SET_TX_DMA_LEN(1),
+ i2c_bus->reg_base + AST2600_I2CS_DMA_LEN);
+ cmd = TARGET_TRIGGER_CMD | AST2600_I2CS_TX_DMA_EN;
+ break;
+ case AST2600_I2CS_WAIT_TX_DMA:
+ /* it should be next start read */
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_READ_PROCESSED,
+ &i2c_bus->target_dma_buf[0]);
+ writel(AST2600_I2CS_SET_TX_DMA_LEN(1),
+ i2c_bus->reg_base + AST2600_I2CS_DMA_LEN);
+ cmd = TARGET_TRIGGER_CMD | AST2600_I2CS_TX_DMA_EN;
+ break;
+ case AST2600_I2CS_TX_NAK | AST2600_I2CS_STOP:
+ /* it just tx complete */
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_STOP, &value);
+ writel(AST2600_I2CS_SET_RX_DMA_LEN(I2C_TARGET_MSG_BUF_SIZE),
+ i2c_bus->reg_base + AST2600_I2CS_DMA_LEN);
+ cmd = TARGET_TRIGGER_CMD | AST2600_I2CS_RX_DMA_EN;
+ break;
+ case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE:
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_REQUESTED, &value);
+ break;
+ case AST2600_I2CS_STOP:
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_STOP, &value);
+ break;
+ default:
+ dev_dbg(i2c_bus->dev, "unhandled target isr case %x, sts %x\n", sts,
+ readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF));
+ break;
+ }
+
+ if (cmd)
+ writel(cmd, i2c_bus->reg_base + AST2600_I2CS_CMD_STS);
+ writel(AST2600_I2CS_PKT_DONE, i2c_bus->reg_base + AST2600_I2CS_ISR);
+ readl(i2c_bus->reg_base + AST2600_I2CS_ISR);
+}
+
+static void ast2600_i2c_target_packet_buff_irq(struct ast2600_i2c_bus *i2c_bus, u32 sts)
+{
+ int target_rx_len = 0;
+ u32 cmd = 0;
+ u8 value;
+ int i;
+
+ /* due to controller target is common buffer, need force the master stop not issue */
+ if (readl(i2c_bus->reg_base + AST2600_I2CM_CMD_STS) & GENMASK(15, 0)) {
+ writel(0, i2c_bus->reg_base + AST2600_I2CM_CMD_STS);
+ i2c_bus->cmd_err = -EBUSY;
+ writel(0, i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL);
+ complete(&i2c_bus->cmd_complete);
+ }
+
+ /* Handle i2c target timeout condition */
+ if (AST2600_I2CS_INACTIVE_TO & sts) {
+ /* Reset timeout counter */
+ u32 ac_timing = readl(i2c_bus->reg_base + AST2600_I2CC_AC_TIMING) &
+ AST2600_I2CC_AC_TIMING_MASK;
+
+ writel(ac_timing, i2c_bus->reg_base + AST2600_I2CC_AC_TIMING);
+ ac_timing |= AST2600_I2CC_TTIMEOUT(i2c_bus->timeout);
+ writel(ac_timing, i2c_bus->reg_base + AST2600_I2CC_AC_TIMING);
+ writel(TARGET_TRIGGER_CMD, i2c_bus->reg_base + AST2600_I2CS_CMD_STS);
+ writel(AST2600_I2CS_PKT_DONE, i2c_bus->reg_base + AST2600_I2CS_ISR);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_STOP, &value);
+ WRITE_ONCE(i2c_bus->target_active, false);
+ return;
+ }
+
+ sts &= ~(AST2600_I2CS_PKT_DONE | AST2600_I2CS_PKT_ERROR);
+
+ if (sts & AST2600_I2CS_SLAVE_MATCH)
+ WRITE_ONCE(i2c_bus->target_active, true);
+
+ switch (sts) {
+ case AST2600_I2CS_SLAVE_PENDING | AST2600_I2CS_WAIT_RX_DMA |
+ AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE | AST2600_I2CS_STOP:
+ case AST2600_I2CS_SLAVE_PENDING |
+ AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE | AST2600_I2CS_STOP:
+ case AST2600_I2CS_SLAVE_PENDING |
+ AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_STOP:
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_STOP, &value);
+ fallthrough;
+ case AST2600_I2CS_SLAVE_PENDING |
+ AST2600_I2CS_WAIT_RX_DMA | AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE:
+ case AST2600_I2CS_WAIT_RX_DMA | AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE:
+ case AST2600_I2CS_WAIT_RX_DMA | AST2600_I2CS_SLAVE_MATCH:
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_REQUESTED, &value);
+ cmd = TARGET_TRIGGER_CMD;
+ if (sts & AST2600_I2CS_RX_DONE) {
+ target_rx_len = AST2600_I2CC_GET_RX_BUF_LEN(readl(i2c_bus->reg_base +
+ AST2600_I2CC_BUFF_CTRL));
+ for (i = 0; i < target_rx_len; i++) {
+ value = readb(i2c_bus->buf_base + 0x10 + i);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_RECEIVED, &value);
+ }
+ }
+ if (readl(i2c_bus->reg_base + AST2600_I2CS_CMD_STS) & AST2600_I2CS_RX_BUFF_EN)
+ cmd = 0;
+ else
+ cmd = TARGET_TRIGGER_CMD | AST2600_I2CS_RX_BUFF_EN;
+
+ writel(AST2600_I2CC_SET_RX_BUF_LEN(i2c_bus->buf_size),
+ i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL);
+ break;
+ case AST2600_I2CS_WAIT_RX_DMA | AST2600_I2CS_RX_DONE:
+ cmd = TARGET_TRIGGER_CMD;
+ target_rx_len = AST2600_I2CC_GET_RX_BUF_LEN(readl(i2c_bus->reg_base +
+ AST2600_I2CC_BUFF_CTRL));
+ for (i = 0; i < target_rx_len; i++) {
+ value = readb(i2c_bus->buf_base + 0x10 + i);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_RECEIVED, &value);
+ }
+ cmd |= AST2600_I2CS_RX_BUFF_EN;
+ writel(AST2600_I2CC_SET_RX_BUF_LEN(i2c_bus->buf_size),
+ i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL);
+ break;
+ case AST2600_I2CS_SLAVE_PENDING | AST2600_I2CS_WAIT_RX_DMA |
+ AST2600_I2CS_RX_DONE | AST2600_I2CS_STOP:
+ cmd = TARGET_TRIGGER_CMD;
+ target_rx_len = AST2600_I2CC_GET_RX_BUF_LEN(readl(i2c_bus->reg_base +
+ AST2600_I2CC_BUFF_CTRL));
+ for (i = 0; i < target_rx_len; i++) {
+ value = readb(i2c_bus->buf_base + 0x10 + i);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_RECEIVED, &value);
+ }
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_STOP, &value);
+ cmd |= AST2600_I2CS_RX_BUFF_EN;
+ writel(AST2600_I2CC_SET_RX_BUF_LEN(i2c_bus->buf_size),
+ i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL);
+ break;
+ case AST2600_I2CS_SLAVE_PENDING | AST2600_I2CS_RX_DONE | AST2600_I2CS_STOP:
+ cmd = TARGET_TRIGGER_CMD;
+ target_rx_len = AST2600_I2CC_GET_RX_BUF_LEN(readl(i2c_bus->reg_base +
+ AST2600_I2CC_BUFF_CTRL));
+ for (i = 0; i < target_rx_len; i++) {
+ value = readb(i2c_bus->buf_base + 0x10 + i);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_RECEIVED, &value);
+ }
+ /* workaround for avoid next start with len != 0 */
+ writel(BIT(0), i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_STOP, &value);
+ break;
+ case AST2600_I2CS_RX_DONE | AST2600_I2CS_STOP:
+ cmd = TARGET_TRIGGER_CMD;
+ target_rx_len = AST2600_I2CC_GET_RX_BUF_LEN(readl(i2c_bus->reg_base +
+ AST2600_I2CC_BUFF_CTRL));
+ for (i = 0; i < target_rx_len; i++) {
+ value = readb(i2c_bus->buf_base + 0x10 + i);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_RECEIVED, &value);
+ }
+ /* workaround for avoid next start with len != 0 */
+ writel(BIT(0), i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_STOP, &value);
+ break;
+ case AST2600_I2CS_SLAVE_PENDING | AST2600_I2CS_RX_DONE |
+ AST2600_I2CS_WAIT_TX_DMA | AST2600_I2CS_STOP:
+ target_rx_len = AST2600_I2CC_GET_RX_BUF_LEN(readl(i2c_bus->reg_base +
+ AST2600_I2CC_BUFF_CTRL));
+ for (i = 0; i < target_rx_len; i++) {
+ value = readb(i2c_bus->buf_base + 0x10 + i);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_RECEIVED, &value);
+ }
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_STOP, &value);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_READ_REQUESTED, &value);
+ writeb(value, i2c_bus->buf_base);
+ break;
+ case AST2600_I2CS_WAIT_TX_DMA | AST2600_I2CS_SLAVE_MATCH:
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_READ_REQUESTED, &value);
+ writeb(value, i2c_bus->buf_base);
+ writel(AST2600_I2CC_SET_TX_BUF_LEN(1),
+ i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL);
+ cmd = TARGET_TRIGGER_CMD | AST2600_I2CS_TX_BUFF_EN;
+ break;
+ case AST2600_I2CS_SLAVE_PENDING | AST2600_I2CS_STOP |
+ AST2600_I2CS_TX_NAK | AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE:
+ case AST2600_I2CS_SLAVE_PENDING | AST2600_I2CS_WAIT_RX_DMA | AST2600_I2CS_STOP |
+ AST2600_I2CS_TX_NAK | AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE:
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_STOP, &value);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_REQUESTED, &value);
+ target_rx_len = AST2600_I2CC_GET_RX_BUF_LEN(readl(i2c_bus->reg_base +
+ AST2600_I2CC_BUFF_CTRL));
+ for (i = 0; i < target_rx_len; i++) {
+ value = readb(i2c_bus->buf_base + 0x10 + i);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_RECEIVED, &value);
+ }
+ writel(AST2600_I2CC_SET_RX_BUF_LEN(i2c_bus->buf_size),
+ i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL);
+ cmd = TARGET_TRIGGER_CMD | AST2600_I2CS_RX_BUFF_EN;
+ break;
+ case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_WAIT_TX_DMA | AST2600_I2CS_RX_DONE:
+ case AST2600_I2CS_WAIT_TX_DMA | AST2600_I2CS_RX_DONE:
+ case AST2600_I2CS_WAIT_TX_DMA:
+ if (sts & AST2600_I2CS_SLAVE_MATCH)
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_REQUESTED, &value);
+
+ if (sts & AST2600_I2CS_RX_DONE) {
+ target_rx_len = AST2600_I2CC_GET_RX_BUF_LEN(readl(i2c_bus->reg_base +
+ AST2600_I2CC_BUFF_CTRL));
+ for (i = 0; i < target_rx_len; i++) {
+ value = readb(i2c_bus->buf_base + 0x10 + i);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_RECEIVED, &value);
+ }
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_READ_REQUESTED, &value);
+ } else {
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_READ_PROCESSED, &value);
+ }
+ writeb(value, i2c_bus->buf_base);
+ writel(AST2600_I2CC_SET_TX_BUF_LEN(1),
+ i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL);
+ cmd = TARGET_TRIGGER_CMD | AST2600_I2CS_TX_BUFF_EN;
+ break;
+ /* workaround : trigger the cmd twice to fix next state keep 1000000 */
+ case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE:
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_REQUESTED, &value);
+ cmd = TARGET_TRIGGER_CMD | AST2600_I2CS_RX_BUFF_EN;
+ writel(cmd, i2c_bus->reg_base + AST2600_I2CS_CMD_STS);
+ break;
+ case AST2600_I2CS_TX_NAK | AST2600_I2CS_STOP:
+ case AST2600_I2CS_STOP:
+ cmd = TARGET_TRIGGER_CMD;
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_STOP, &value);
+ break;
+ default:
+ dev_dbg(i2c_bus->dev, "unhandled target isr case %x, sts %x\n", sts,
+ readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF));
+ break;
+ }
+
+ if (cmd)
+ writel(cmd, i2c_bus->reg_base + AST2600_I2CS_CMD_STS);
+ writel(AST2600_I2CS_PKT_DONE, i2c_bus->reg_base + AST2600_I2CS_ISR);
+ readl(i2c_bus->reg_base + AST2600_I2CS_ISR);
+
+ if ((sts & AST2600_I2CS_STOP) && !(sts & AST2600_I2CS_SLAVE_PENDING))
+ WRITE_ONCE(i2c_bus->target_active, false);
+}
+
+static void ast2600_i2c_target_byte_irq(struct ast2600_i2c_bus *i2c_bus, u32 sts)
+{
+ u32 i2c_buff = readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF);
+ u32 cmd = AST2600_I2CS_ACTIVE_ALL;
+ u8 byte_data;
+ u8 value;
+
+ /* Handle i2c target timeout condition */
+ if (sts & AST2600_I2CS_INACTIVE_TO) {
+ /* Reset timeout counter */
+ u32 ac_timing = readl(i2c_bus->reg_base + AST2600_I2CC_AC_TIMING) &
+ AST2600_I2CC_AC_TIMING_MASK;
+
+ writel(ac_timing, i2c_bus->reg_base + AST2600_I2CC_AC_TIMING);
+ ac_timing |= AST2600_I2CC_TTIMEOUT(i2c_bus->timeout);
+ writel(ac_timing, i2c_bus->reg_base + AST2600_I2CC_AC_TIMING);
+ writel(AST2600_I2CS_ACTIVE_ALL, i2c_bus->reg_base + AST2600_I2CS_CMD_STS);
+ writel(sts, i2c_bus->reg_base + AST2600_I2CS_ISR);
+ readl(i2c_bus->reg_base + AST2600_I2CS_ISR);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_STOP, &value);
+ WRITE_ONCE(i2c_bus->target_active, false);
+ return;
+ }
+
+ switch (sts) {
+ case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE | AST2600_I2CS_WAIT_RX_DMA:
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_REQUESTED, &value);
+ /* first address match is address */
+ byte_data = AST2600_I2CC_GET_RX_BUFF(i2c_buff);
+ break;
+ case AST2600_I2CS_RX_DONE | AST2600_I2CS_WAIT_RX_DMA:
+ byte_data = AST2600_I2CC_GET_RX_BUFF(i2c_buff);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_RECEIVED, &byte_data);
+ break;
+ case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE | AST2600_I2CS_WAIT_TX_DMA:
+ cmd |= AST2600_I2CS_TX_CMD;
+ byte_data = AST2600_I2CC_GET_RX_BUFF(i2c_buff);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_READ_REQUESTED, &byte_data);
+ writel(byte_data, i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF);
+ break;
+ case AST2600_I2CS_TX_ACK | AST2600_I2CS_WAIT_TX_DMA:
+ cmd |= AST2600_I2CS_TX_CMD;
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_READ_PROCESSED, &byte_data);
+ writel(byte_data, i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF);
+ break;
+ case AST2600_I2CS_STOP:
+ case AST2600_I2CS_STOP | AST2600_I2CS_TX_NAK:
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_STOP, &value);
+ break;
+ default:
+ dev_dbg(i2c_bus->dev, "unhandled pkt isr %x\n", sts);
+ break;
+ }
+ writel(cmd, i2c_bus->reg_base + AST2600_I2CS_CMD_STS);
+ writel(sts, i2c_bus->reg_base + AST2600_I2CS_ISR);
+ readl(i2c_bus->reg_base + AST2600_I2CS_ISR);
+}
+
+static int ast2600_i2c_target_irq(struct ast2600_i2c_bus *i2c_bus)
+{
+ u32 ier = readl(i2c_bus->reg_base + AST2600_I2CS_IER);
+ u32 isr = readl(i2c_bus->reg_base + AST2600_I2CS_ISR);
+
+ if (!(isr & ier))
+ return 0;
+
+ /*
+ * Target interrupt coming after controller packet done
+ * So need handle controller first.
+ */
+ if (readl(i2c_bus->reg_base + AST2600_I2CM_ISR) & AST2600_I2CM_PKT_DONE)
+ return 0;
+
+ isr &= ~(AST2600_I2CS_ADDR_INDICATE_MASK);
+
+ if (AST2600_I2CS_ADDR1_NAK & isr)
+ isr &= ~AST2600_I2CS_ADDR1_NAK;
+
+ if (AST2600_I2CS_ADDR2_NAK & isr)
+ isr &= ~AST2600_I2CS_ADDR2_NAK;
+
+ if (AST2600_I2CS_ADDR3_NAK & isr)
+ isr &= ~AST2600_I2CS_ADDR3_NAK;
+
+ if (AST2600_I2CS_ADDR_MASK & isr)
+ isr &= ~AST2600_I2CS_ADDR_MASK;
+
+ if (AST2600_I2CS_PKT_DONE & isr) {
+ if (i2c_bus->mode == DMA_MODE)
+ ast2600_i2c_target_packet_dma_irq(i2c_bus, isr);
+ else
+ ast2600_i2c_target_packet_buff_irq(i2c_bus, isr);
+ } else {
+ ast2600_i2c_target_byte_irq(i2c_bus, isr);
+ }
+
+ return 1;
+}
+#endif
+
static int ast2600_i2c_setup_dma_tx(u32 cmd, struct ast2600_i2c_bus *i2c_bus)
{
struct i2c_msg *msg = &i2c_bus->msgs[i2c_bus->msgs_index];
@@ -629,6 +1070,20 @@ static void ast2600_i2c_controller_packet_irq(struct ast2600_i2c_bus *i2c_bus, u
}
break;
case AST2600_I2CM_RX_DONE:
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ /*
+ * Workaround for controller/target packet mode enable rx done stuck issue
+ * When controller go for first read (RX_DONE), target mode will also effect
+ * Then controller will send nack, not operate anymore.
+ */
+ if (readl(i2c_bus->reg_base + AST2600_I2CS_CMD_STS) & AST2600_I2CS_PKT_MODE_EN) {
+ u32 target_cmd = readl(i2c_bus->reg_base + AST2600_I2CS_CMD_STS);
+
+ writel(0, i2c_bus->reg_base + AST2600_I2CS_CMD_STS);
+ writel(target_cmd, i2c_bus->reg_base + AST2600_I2CS_CMD_STS);
+ }
+ fallthrough;
+#endif
case AST2600_I2CM_RX_DONE | AST2600_I2CM_NORMAL_STOP:
/* do next rx */
if (i2c_bus->mode == DMA_MODE) {
@@ -727,6 +1182,12 @@ static irqreturn_t ast2600_i2c_bus_irq(int irq, void *dev_id)
{
struct ast2600_i2c_bus *i2c_bus = dev_id;
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ if (i2c_bus->target) {
+ if (ast2600_i2c_target_irq(i2c_bus))
+ return IRQ_HANDLED;
+ }
+#endif
return IRQ_RETVAL(ast2600_i2c_controller_irq(i2c_bus));
}
@@ -743,12 +1204,35 @@ static int ast2600_i2c_controller_xfer(struct i2c_adapter *adap, struct i2c_msg
return ret;
}
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ if (i2c_bus->mode == BUFF_MODE) {
+ if (i2c_bus->target_active)
+ return -EBUSY;
+ /**
+ * In BUFF_MODE, controller and target share the same buffer register,
+ * A target transaction can update buffer state asynchronously via IRQ,
+ * so block controller transfers while target is active, otherwise we can
+ * corrupt buffer.
+ */
+ writel(0, i2c_bus->reg_base + AST2600_I2CS_IER);
+ if (readl(i2c_bus->reg_base + AST2600_I2CS_ISR) || i2c_bus->target_active) {
+ writel(AST2600_I2CS_PKT_DONE, i2c_bus->reg_base + AST2600_I2CS_IER);
+ return -EBUSY;
+ }
+ }
+#endif
+
i2c_bus->cmd_err = 0;
i2c_bus->msgs = msgs;
i2c_bus->msgs_index = 0;
i2c_bus->msgs_count = num;
reinit_completion(&i2c_bus->cmd_complete);
ret = ast2600_i2c_do_start(i2c_bus);
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ /* avoid race condition target is wait and controller wait 1st target operate */
+ if (i2c_bus->mode == BUFF_MODE)
+ writel(AST2600_I2CS_PKT_DONE, i2c_bus->reg_base + AST2600_I2CS_IER);
+#endif
if (ret)
goto controller_out;
timeout = wait_for_completion_timeout(&i2c_bus->cmd_complete, i2c_bus->adap.timeout);
@@ -767,6 +1251,9 @@ static int ast2600_i2c_controller_xfer(struct i2c_adapter *adap, struct i2c_msg
* if the bus is still busy.
*/
if (i2c_bus->multi_master &&
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ !i2c_bus->target_active &&
+#endif
(readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF) &
AST2600_I2CC_BUS_BUSY_STS))
ast2600_i2c_recover_bus(i2c_bus);
@@ -814,8 +1301,80 @@ static int ast2600_i2c_init(struct ast2600_i2c_bus *i2c_bus)
/* Clear Interrupt */
writel(GENMASK(27, 0), i2c_bus->reg_base + AST2600_I2CM_ISR);
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ /* for memory buffer initial */
+ if (i2c_bus->dma_available) {
+ i2c_bus->target_dma_buf =
+ dmam_alloc_coherent(i2c_bus->dev, I2C_TARGET_MSG_BUF_SIZE,
+ &i2c_bus->target_dma_addr, GFP_KERNEL);
+ if (!i2c_bus->target_dma_buf)
+ return -ENOMEM;
+ }
+
+ writel(GENMASK(27, 0), i2c_bus->reg_base + AST2600_I2CS_ISR);
+
+ if (i2c_bus->mode == BYTE_MODE)
+ writel(GENMASK(15, 0), i2c_bus->reg_base + AST2600_I2CS_IER);
+ else
+ writel(AST2600_I2CS_PKT_DONE, i2c_bus->reg_base + AST2600_I2CS_IER);
+#endif
+
+ return 0;
+}
+
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+static int ast2600_i2c_reg_target(struct i2c_client *client)
+{
+ struct ast2600_i2c_bus *i2c_bus = i2c_get_adapdata(client->adapter);
+ u32 cmd = TARGET_TRIGGER_CMD;
+
+ if (i2c_bus->target)
+ return -EINVAL;
+
+ dev_dbg(i2c_bus->dev, "target addr %x\n", client->addr);
+
+ writel(0, i2c_bus->reg_base + AST2600_I2CS_ADDR_CTRL);
+ writel(AST2600_I2CC_SLAVE_EN | readl(i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL),
+ i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+
+ /* trigger rx buffer */
+ if (i2c_bus->mode == DMA_MODE) {
+ cmd |= AST2600_I2CS_RX_DMA_EN;
+ writel(i2c_bus->target_dma_addr, i2c_bus->reg_base + AST2600_I2CS_RX_DMA);
+ writel(i2c_bus->target_dma_addr, i2c_bus->reg_base + AST2600_I2CS_TX_DMA);
+ writel(AST2600_I2CS_SET_RX_DMA_LEN(I2C_TARGET_MSG_BUF_SIZE),
+ i2c_bus->reg_base + AST2600_I2CS_DMA_LEN);
+ } else if (i2c_bus->mode == BUFF_MODE) {
+ cmd = TARGET_TRIGGER_CMD;
+ } else {
+ cmd &= ~AST2600_I2CS_PKT_MODE_EN;
+ }
+
+ writel(cmd, i2c_bus->reg_base + AST2600_I2CS_CMD_STS);
+ i2c_bus->target = client;
+ /* Set target addr. */
+ writel(client->addr | AST2600_I2CS_ADDR1_ENABLE,
+ i2c_bus->reg_base + AST2600_I2CS_ADDR_CTRL);
+
+ return 0;
+}
+
+static int ast2600_i2c_unreg_target(struct i2c_client *client)
+{
+ struct ast2600_i2c_bus *i2c_bus = i2c_get_adapdata(client->adapter);
+ u32 val;
+
+ /* Turn off target mode. */
+ val = readl(i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+ writel(val & ~AST2600_I2CC_SLAVE_EN, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+ val = readl(i2c_bus->reg_base + AST2600_I2CS_ADDR_CTRL);
+ writel(val & ~AST2600_I2CS_ADDR1_MASK, i2c_bus->reg_base + AST2600_I2CS_ADDR_CTRL);
+
+ i2c_bus->target = NULL;
+
return 0;
}
+#endif
static u32 ast2600_i2c_functionality(struct i2c_adapter *adap)
{
@@ -825,6 +1384,10 @@ static u32 ast2600_i2c_functionality(struct i2c_adapter *adap)
static const struct i2c_algorithm i2c_ast2600_algorithm = {
.xfer = ast2600_i2c_controller_xfer,
.functionality = ast2600_i2c_functionality,
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ .reg_target = ast2600_i2c_reg_target,
+ .unreg_target = ast2600_i2c_unreg_target,
+#endif
};
static void ast2600_i2c_set_xfer_mode(struct ast2600_i2c_bus *i2c_bus,
@@ -960,6 +1523,9 @@ static int ast2600_i2c_probe(struct platform_device *pdev)
regmap_write(i2c_bus->global_regs, AST2600_I2CG_CLK_DIV_CTRL, I2CCG_DIV_CTRL);
}
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ WRITE_ONCE(i2c_bus->target_active, false);
+#endif
i2c_bus->dev = dev;
i2c_bus->multi_master = device_property_read_bool(dev, "multi-master");
i2c_bus->dma_available = device_property_read_bool(dev, "aspeed,enable-dma");
--
2.34.1
^ permalink raw reply related [flat|nested] 11+ messages in thread