[PATCH v1 1/1] i2c: designware: Add ACPI ID MSFT0006 for Microsoft Cobalt SoCs

[PATCH v1 1/1] i2c: designware: Add ACPI ID MSFT0006 for Microsoft Cobalt SoCs

[Siddharth Chintamaneni]

Add the MSFT0006 ACPI ID for the DesignWare I2C controller integrated
on Microsoft Cobalt SoCs, along with its 300 MHz input clock description
in acpi_apd.c.

Without an explicit MSFT0006 entry, ACPI device matching falls back to
its _CID (APMC0D0F), which configures a 100 MHz input clock instead of
the controller's actual 300 MHz clock.

Cc: Jarred White <jarredwhite@microsoft.com>
Cc: Jeff Kirsher <jeff.kirsher@microsoft.com>
Signed-off-by: Siddharth Chintamaneni <sidchintamaneni@gmail.com>
---
 drivers/acpi/acpi_apd.c                     | 6 ++++++
 drivers/i2c/busses/i2c-designware-platdrv.c | 1 +
 2 files changed, 7 insertions(+)

diff --git a/drivers/acpi/acpi_apd.c b/drivers/acpi/acpi_apd.c
index 9fc667d6776c8..a1baa056931c4 100644
--- a/drivers/acpi/acpi_apd.c
+++ b/drivers/acpi/acpi_apd.c
@@ -198,6 +198,11 @@ static const struct apd_device_desc hjmc_i2c_desc = {
 	.fixed_clk_rate = 200 * HZ_PER_MHZ,
 };
 
+static const struct apd_device_desc msft_i2c_desc = {
+	.setup = acpi_apd_setup,
+	.fixed_clk_rate = 300 * HZ_PER_MHZ,
+};
+
 #endif /* CONFIG_ARM64 */
 
 #endif
@@ -272,6 +277,7 @@ static const struct acpi_device_id acpi_apd_device_ids[] = {
 	{ "HJMC3001", APD_ADDR(hjmc_i2c_desc) },
 	{ "LECA0002", APD_ADDR(leca_spi_desc) },
 	{ "LECA0003", APD_ADDR(leca_i2c_desc) },
+	{ "MSFT0006", APD_ADDR(msft_i2c_desc) },
 	{ "NXP0001", APD_ADDR(nxp_i2c_desc) },
 #endif
 	{ }
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
index 1da6b0314b6a0..f359d38cc63c7 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -280,6 +280,7 @@ static const struct acpi_device_id dw_i2c_acpi_match[] = {
 	{ .id = "INT3433" },
 	{ .id = "INTC10EF" },
 	{ .id = "LECA0003" },
+	{ .id = "MSFT0006" },
 	{ }
 };
 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match);
-- 
2.45.4

Re: [PATCH v1 1/1] i2c: designware: Add ACPI ID MSFT0006 for Microsoft Cobalt SoCs

[Andy Shevchenko]

On Wed, Nov 04, 2026 at 11:49:28PM +0000, Siddharth Chintamaneni wrote:
> Add the MSFT0006 ACPI ID for the DesignWare I2C controller integrated
> on Microsoft Cobalt SoCs, along with its 300 MHz input clock description
> in acpi_apd.c.
> 
> Without an explicit MSFT0006 entry, ACPI device matching falls back to
> its _CID (APMC0D0F), which configures a 100 MHz input clock instead of
> the controller's actual 300 MHz clock.

> Cc: Jarred White <jarredwhite@microsoft.com>
> Cc: Jeff Kirsher <jeff.kirsher@microsoft.com>

Move Cc list after the '---' line below. It will reduce the noise in the commit
message and hence Git history.

> Signed-off-by: Siddharth Chintamaneni <sidchintamaneni@gmail.com>
> ---

Cc list goes here...

>  drivers/i2c/busses/i2c-designware-platdrv.c | 1 +
>  2 files changed, 7 insertions(+)

Code wise LGTM, I assume MS allocated that HID for the specific device and
we will not see collisions in the future.

-- 
With Best Regards,
Andy Shevchenko