The I2C controller requires a reset to ensure it starts from a clean state.
Add the 'resets' property to support this hardware requirement.
Reviewed-by: Troy Mitchell <troy.mitchell@linux.spacemit.com>
Signed-off-by: Encrow Thorne <jyc0019@gmail.com>
---
Documentation/devicetree/bindings/i2c/spacemit,k1-i2c.yaml | 3 +++
1 file changed, 3 insertions(+)
diff --git a/Documentation/devicetree/bindings/i2c/spacemit,k1-i2c.yaml b/Documentation/devicetree/bindings/i2c/spacemit,k1-i2c.yaml
index b7220fff2235..5896fb120501 100644
--- a/Documentation/devicetree/bindings/i2c/spacemit,k1-i2c.yaml
+++ b/Documentation/devicetree/bindings/i2c/spacemit,k1-i2c.yaml
@@ -41,6 +41,9 @@ properties:
default: 400000
maximum: 3300000
+ resets:
+ maxItems: 1
+
required:
- compatible
- reg
--
2.25.1On Tue, 30 Dec 2025 23:06:51 +0800, Encrow Thorne wrote: > The I2C controller requires a reset to ensure it starts from a clean state. > > Add the 'resets' property to support this hardware requirement. > > Reviewed-by: Troy Mitchell <troy.mitchell@linux.spacemit.com> > Signed-off-by: Encrow Thorne <jyc0019@gmail.com> > --- > Documentation/devicetree/bindings/i2c/spacemit,k1-i2c.yaml | 3 +++ > 1 file changed, 3 insertions(+) > Acked-by: Rob Herring (Arm) <robh@kernel.org>
The K1 I2C controller provides a reset line that needs to be deasserted
before the controller can be accessed.
Add reset support to the driver to ensure the controller starts in the
required state.
Reviewed-by: Troy Mitchell <troy.mitchell@linux.spacemit.com>
Signed-off-by: Encrow Thorne <jyc0019@gmail.com>
---
drivers/i2c/busses/i2c-k1.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/i2c/busses/i2c-k1.c b/drivers/i2c/busses/i2c-k1.c
index d42c03ef5db5..23661c7ddb67 100644
--- a/drivers/i2c/busses/i2c-k1.c
+++ b/drivers/i2c/busses/i2c-k1.c
@@ -10,6 +10,7 @@
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
+ #include <linux/reset.h>
/* spacemit i2c registers */
#define SPACEMIT_ICR 0x0 /* Control register */
@@ -534,6 +535,7 @@ static int spacemit_i2c_probe(struct platform_device *pdev)
struct device *dev = &pdev->dev;
struct device_node *of_node = pdev->dev.of_node;
struct spacemit_i2c_dev *i2c;
+ struct reset_control *rst;
int ret;
i2c = devm_kzalloc(dev, sizeof(*i2c), GFP_KERNEL);
@@ -578,6 +580,11 @@ static int spacemit_i2c_probe(struct platform_device *pdev)
if (IS_ERR(clk))
return dev_err_probe(dev, PTR_ERR(clk), "failed to enable bus clock");
+ rst = devm_reset_control_get_optional_exclusive_deasserted(dev, NULL);
+ if (IS_ERR(rst))
+ return dev_err_probe(dev, PTR_ERR(rst),
+ "failed to acquire deasserted reset\n");
+
spacemit_i2c_reset(i2c);
i2c_set_adapdata(&i2c->adapt, i2c);
--
2.25.1Add resets property to K1 I2C node.
---
arch/riscv/boot/dts/spacemit/k1.dtsi | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/arch/riscv/boot/dts/spacemit/k1.dtsi b/arch/riscv/boot/dts/spacemit/k1.dtsi
index 7818ca4979b6..085987643638 100644
--- a/arch/riscv/boot/dts/spacemit/k1.dtsi
+++ b/arch/riscv/boot/dts/spacemit/k1.dtsi
@@ -367,6 +367,7 @@ i2c0: i2c@d4010800 {
<&syscon_apbc CLK_TWSI0_BUS>;
clock-names = "func", "bus";
clock-frequency = <400000>;
+ resets = <&syscon_apbc RESET_TWSI0>;
interrupts = <36>;
status = "disabled";
};
@@ -380,6 +381,7 @@ i2c1: i2c@d4011000 {
<&syscon_apbc CLK_TWSI1_BUS>;
clock-names = "func", "bus";
clock-frequency = <400000>;
+ resets = <&syscon_apbc RESET_TWSI1>;
interrupts = <37>;
status = "disabled";
};
@@ -393,6 +395,7 @@ i2c2: i2c@d4012000 {
<&syscon_apbc CLK_TWSI2_BUS>;
clock-names = "func", "bus";
clock-frequency = <400000>;
+ resets = <&syscon_apbc RESET_TWSI2>;
interrupts = <38>;
status = "disabled";
};
@@ -406,6 +409,7 @@ i2c4: i2c@d4012800 {
<&syscon_apbc CLK_TWSI4_BUS>;
clock-names = "func", "bus";
clock-frequency = <400000>;
+ resets = <&syscon_apbc RESET_TWSI4>;
interrupts = <40>;
status = "disabled";
};
@@ -419,6 +423,7 @@ i2c5: i2c@d4013800 {
<&syscon_apbc CLK_TWSI5_BUS>;
clock-names = "func", "bus";
clock-frequency = <400000>;
+ resets = <&syscon_apbc RESET_TWSI5>;
interrupts = <41>;
status = "disabled";
};
@@ -443,6 +448,7 @@ i2c6: i2c@d4018800 {
<&syscon_apbc CLK_TWSI6_BUS>;
clock-names = "func", "bus";
clock-frequency = <400000>;
+ resets = <&syscon_apbc RESET_TWSI6>;
interrupts = <70>;
status = "disabled";
};
@@ -546,6 +552,7 @@ i2c7: i2c@d401d000 {
<&syscon_apbc CLK_TWSI7_BUS>;
clock-names = "func", "bus";
clock-frequency = <400000>;
+ resets = <&syscon_apbc RESET_TWSI7>;
interrupts = <18>;
status = "disabled";
};
@@ -559,6 +566,7 @@ i2c8: i2c@d401d800 {
<&syscon_apbc CLK_TWSI8_BUS>;
clock-names = "func", "bus";
clock-frequency = <400000>;
+ resets = <&syscon_apbc RESET_TWSI8>;
interrupts = <19>;
status = "disabled";
};
--
2.25.1Hi Encrow, On Tue, Dec 30, 2025 at 11:06:53PM +0800, Encrow Thorne wrote: > Add resets property to K1 I2C node. > --- > arch/riscv/boot/dts/spacemit/k1.dtsi | 8 ++++++++ > 1 file changed, 8 insertions(+) how is this patch formatted? Andi
On Wed, Jan 07, 2026 at 03:22:42PM +0100, Andi Shyti wrote: Hi Andi, > Hi Encrow, > > On Tue, Dec 30, 2025 at 11:06:53PM +0800, Encrow Thorne wrote: > > Add resets property to K1 I2C node. > > --- > > arch/riscv/boot/dts/spacemit/k1.dtsi | 8 ++++++++ > > 1 file changed, 8 insertions(+) > > how is this patch formatted? > Sorry, I forgot to add the version number when I resent it. The initial sending process was interrupted, so I manually regenerated the patches using git format-patch and sent them again.I have verified locally that the entire patch series applies cleanly. Please let me know if you find any other formatting issues. Encrow > Andi
Hi Encrow, On Thu, Jan 08, 2026 at 12:23:43AM +0800, Encrow Thorne wrote: > On Wed, Jan 07, 2026 at 03:22:42PM +0100, Andi Shyti wrote: > Hi Andi, > > Hi Encrow, > > > > On Tue, Dec 30, 2025 at 11:06:53PM +0800, Encrow Thorne wrote: > > > Add resets property to K1 I2C node. > > > --- > > > arch/riscv/boot/dts/spacemit/k1.dtsi | 8 ++++++++ > > > 1 file changed, 8 insertions(+) > > > > how is this patch formatted? > > > Sorry, I forgot to add the version number when I resent it. you also forgot the tag section :-) No worries, I took patch 1 and 2 into i2c/i2c-host branch. Thanks, Andi
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