[PATCH 1/3] arm: mach-k3: am62a: Fixup CPU core, DSS, CAN-FD and Video-codec nodes in fdt

[Daniel Schultz]

On 5/1/25 14:28, Nishanth Menon wrote:
> On 16:12-20250430, Aparna Patra wrote:
>> AM62A SOC is available in multiple variants:
>> -CPU cores (Cortex-A) AM62Ax1 (1 core),
>>   AM62Ax2 (2 cores), AM62Ax4 (4 cores)
>> -With and without DSS, CAN-FD & Video-codec support
>>
>> Remove the relevant FDT nodes by reading the actual configuration
>> from the SoC registers, with that change it is possible to have a single
>> dts/dtb file handling the different variants at runtime.
>>
>> Signed-off-by: Aparna Patra <a-patra at ti.com>
>> ---
>>   arch/arm/mach-k3/am62ax/am62a7_fdt.c          | 41 +++++++++++++++++++
>>   .../arm/mach-k3/include/mach/am62a_hardware.h | 40 ++++++++++++++++++
>>   2 files changed, 81 insertions(+)
>>
>> diff --git a/arch/arm/mach-k3/am62ax/am62a7_fdt.c b/arch/arm/mach-k3/am62ax/am62a7_fdt.c
>> index 7f764ab36b..56fd658202 100644
>> --- a/arch/arm/mach-k3/am62ax/am62a7_fdt.c
>> +++ b/arch/arm/mach-k3/am62ax/am62a7_fdt.c
>> @@ -8,8 +8,49 @@
>>   
>>   #include "../common_fdt.h"
>>   
>> +static void fdt_fixup_cores_wdt_nodes_am62a(void *blob, int core_nr)
>> +{
>> +	char node_path[32];
>> +
>> +	if (core_nr < 1)
>> +		return;
>> +
>> +	for (; core_nr < 4; core_nr++) {
>> +		snprintf(node_path, sizeof(node_path), "/cpus/cpu@%d", core_nr);
>> +		fdt_del_node_path(blob, node_path);
>> +		snprintf(node_path, sizeof(node_path), "/cpus/cpu-map/cluster0/core%d", core_nr);
>> +		fdt_del_node_path(blob, node_path);
>> +		snprintf(node_path, sizeof(node_path), "/bus at f0000/watchdog at e0%d0000", core_nr);
>> +		fdt_del_node_path(blob, node_path);
>> +	}
>> +}
>> +
>> +static void fdt_fixup_dss_nodes_am62a(void *blob, bool has_dss)
>> +{
>> +	if (!has_dss) {
>> +		fdt_del_node_path(blob, "/bus at f0000/dss at 30200000");
>> +		fdt_del_node_path(blob, "/bus at f0000/pinctrl at f4000/main-dss0-default-pins");
>> +	}
>> +}
>> +
>> +static void fdt_fixup_video_codec_nodes_am62a(void *blob, bool has_video_codec)
>> +{
>> +	if (!has_video_codec)
>> +		fdt_del_node_path(blob, "/bus at f0000/video-codec at 30210000");
>> +}
>> +
>> +static void fdt_fixup_canfd_nodes_am62a(void *blob, bool has_canfd)
>> +{
>> +	if (!has_canfd)
>> +		fdt_del_node_path(blob, "/bus at f0000/can at 20701000");
>> +}
>> +
>>   int ft_system_setup(void *blob, struct bd_info *bd)
>>   {
>> +	fdt_fixup_cores_wdt_nodes_am62a(blob, k3_get_core_nr());
>> +	fdt_fixup_dss_nodes_am62a(blob, k3_has_dss());
>> +	fdt_fixup_video_codec_nodes_am62a(blob, k3_has_video_codec());
>> +	fdt_fixup_canfd_nodes_am62a(blob, k3_has_canfd());
>>   	fdt_fixup_reserved(blob, "tfa", CONFIG_K3_ATF_LOAD_ADDR, 0x80000);
>>   	fdt_fixup_reserved(blob, "optee", CONFIG_K3_OPTEE_LOAD_ADDR, 0x1800000);
>>   
>> diff --git a/arch/arm/mach-k3/include/mach/am62a_hardware.h b/arch/arm/mach-k3/include/mach/am62a_hardware.h
>> index cd61abe018..ab281129d7 100644
>> --- a/arch/arm/mach-k3/include/mach/am62a_hardware.h
>> +++ b/arch/arm/mach-k3/include/mach/am62a_hardware.h
>> @@ -19,6 +19,18 @@
>>   #define MCU_CTRL_MMR0_BASE			0x04500000
>>   #define WKUP_CTRL_MMR0_BASE			0x43000000
>>   
>> +#define CTRLMMR_WKUP_JTAG_DEVICE_ID		(WKUP_CTRL_MMR0_BASE + 0x18)
>> +#define JTAG_DEV_CORE_NR_MASK			GENMASK(19, 18)
>> +#define JTAG_DEV_CORE_NR_SHIFT			18
>> +#define JTAG_DEV_CANFD_MASK			BIT(15)
>> +#define JTAG_DEV_CANFD_SHIFT			15
>> +#define JTAG_DEV_VIDEO_CODEC_MASK			BIT(14)
>> +#define JTAG_DEV_VIDEO_CODEC_SHIFT			14
>> +#define JTAG_DEV_DSS_MASK			GENMASK(16, 13)
>> +#define JTAG_DEV_DSS_SHIFT			13
>> +
>> +#define JTAG_DEV_HAS_DSS_VALUE			0xD
>> +
>>   #define CTRLMMR_MAIN_DEVSTAT			(WKUP_CTRL_MMR0_BASE + 0x30)
>>   #define MAIN_DEVSTAT_PRIMARY_BOOTMODE_MASK	GENMASK(6, 3)
>>   #define MAIN_DEVSTAT_PRIMARY_BOOTMODE_SHIFT	3
>> @@ -86,6 +98,34 @@
>>   #define TI_SRAM_SCRATCH_BOARD_EEPROM_START	0x70000001
>>   #endif /* CONFIG_CPU_V7R */
>>   
>> +static inline int k3_get_core_nr(void)
>> +{
>> +	u32 dev_id = readl(CTRLMMR_WKUP_JTAG_DEVICE_ID);
>> +
>> +	return ((dev_id & JTAG_DEV_CORE_NR_MASK) >> JTAG_DEV_CORE_NR_SHIFT) + 1;
>> +}
>> +

I can see these three following components are optional but I don't see 
any silicon devices without them. The AM62A processor data sheet only 
lists devices with different A53 and C7 options.

BTW: C7x fixup is missing in this series ;)

>> +static inline int k3_has_dss(void)
>> +{
>> +	u32 dev_id = readl(CTRLMMR_WKUP_JTAG_DEVICE_ID);
>> +
>> +	return (JTAG_DEV_HAS_DSS_VALUE == ((dev_id & JTAG_DEV_DSS_MASK) >> JTAG_DEV_DSS_SHIFT));
>> +}
>> +
>> +static inline int k3_has_video_codec(void)
>> +{
>> +	u32 dev_id = readl(CTRLMMR_WKUP_JTAG_DEVICE_ID);
>> +
>> +	return !((dev_id & JTAG_DEV_VIDEO_CODEC_MASK) >> JTAG_DEV_VIDEO_CODEC_SHIFT);
>> +}
>> +
>> +static inline int k3_has_canfd(void)
>> +{
>> +	u32 dev_id = readl(CTRLMMR_WKUP_JTAG_DEVICE_ID);
>> +
>> +	return (dev_id & JTAG_DEV_CANFD_MASK) >> JTAG_DEV_CANFD_SHIFT;
>> +}
>> +
>>   #if defined(CONFIG_SYS_K3_SPL_ATF) && !defined(__ASSEMBLY__)
>>   
>>   static const u32 put_device_ids[] = {};
>> -- 
>> 2.34.1
>>
> We should do a proper framework for this that scales multiple devices.

I agree, this should be reworked afterwards and moved into a framework. 
We have literally the same logic for AM62 and AM62Ax. I also have 
temperature fixup patches for the AM64 which are identical again. Would 
be nice to move most of this logic into a common part.

Thanks for sending those patches!

- Daniel

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