arch: arm: meson: support Amlogic chip_id v1 and v2

Patch introduces:
* chip_id API - useful for various things, but used now for
  device_id (did) generation as mentioned in [1] on our private board
  code. Our device_id is calculated by means of permutations of
  chip_id value.
* new SoCs (a1, s4, etc) are usually coming with the support of chip_id
  v2 right away, whereas secure monitors on old SoCs (like axg, g12b,
  g12a, etc) may support only chip_id v1. Chip_id API handles both
  cases
* meson_sm_get_serial() is described via chip_id API.

Links:
[1] https://lore.kernel.org/linux-arm-kernel/[email protected]/T/#m630fbeea6a6e7d531290b5c0af205af4fb979757

Signed-off-by: Viacheslav Bocharov <[email protected]>
Co-developed-by: Arseniy Krasnov <[email protected]>
Signed-off-by: Arseniy Krasnov <[email protected]>
Signed-off-by: Evgeny Bachinin <[email protected]>
Link: https://lore.kernel.org/r/20250210-meson_chip_id_all_vers-v1-3-b98f8b6880b8@salutedevices.com
Signed-off-by: Neil Armstrong <[email protected]>

2 files changed, 61 insertions, 1 deletions

diff --git a/arch/arm/include/asm/arch-meson/boot.h b/arch/arm/include/asm/arch-meson/boot.h
index c67d12d06c9..a11dfde719e 100644
--- a/arch/arm/include/asm/arch-meson/boot.h
+++ b/arch/arm/include/asm/arch-meson/boot.h
@@ -21,4 +21,18 @@ int meson_get_boot_device(void);
 
 int meson_get_soc_rev(char *buff, size_t buff_len);
 
+/**
+ * meson_get_socinfo - retrieve cpu_id of the Amlogic SoC
+ *
+ * The value in the following format is read from register:
+ *   +-----------+------------+------------+------------+
+ *   | family_id | package_id |  chip_rev  | layout_rev |
+ *   +-----------+------------+------------+------------+
+ *   | 31     24 | 23      16 | 15       8 | 7        0 |
+ *   +-----------+------------+------------+------------+
+ *
+ * Return: 4 bytes value of cpu_id on success or 0 on failure.
+ */
+u32 meson_get_socinfo(void);
+
 #endif /* __MESON_BOOT_H__ */
diff --git a/arch/arm/include/asm/arch-meson/sm.h b/arch/arm/include/asm/arch-meson/sm.h
index 4b1d564bc48..4d614955fc2 100644
--- a/arch/arm/include/asm/arch-meson/sm.h
+++ b/arch/arm/include/asm/arch-meson/sm.h
@@ -6,6 +6,8 @@
 #ifndef __MESON_SM_H__
 #define __MESON_SM_H__
 
+#include <asm/types.h>
+
 /**
  * meson_sm_read_efuse - read efuse memory into buffer
  *
@@ -27,16 +29,60 @@ ssize_t meson_sm_read_efuse(uintptr_t offset, void *buffer, size_t size);
 ssize_t meson_sm_write_efuse(uintptr_t offset, void *buffer, size_t size);
 
 #define SM_SERIAL_SIZE	12
+#define MESON_CPU_ID_SZ	4
+#define MESON_CHIP_ID_SZ 16
+
+/**
+ * union meson_cpu_id - Amlogic cpu_id.
+ * @raw: buffer to hold the cpu_id value as sequential bytes.
+ * @val: cpu_id represented as 32 bit value.
+ */
+union meson_cpu_id {
+	u8 raw[MESON_CPU_ID_SZ];
+	u32 val;
+};
+
+/**
+ * struct meson_sm_chip_id - Amlogic chip_id.
+ * @cpu_id: cpu_id value, which is distinct from socinfo in that the order of
+ *          PACK & MINOR bytes are swapped according to Amlogic chip_id format.
+ * @serial: 12 byte unique SoC number, identifying particular die, read
+ *          usually from efuse OTP storage. Serial comes in little-endian
+ *          order.
+ */
+struct meson_sm_chip_id {
+	union meson_cpu_id cpu_id;
+	u8 serial[SM_SERIAL_SIZE];
+};
 
 /**
- * meson_sm_get_serial - read chip unique id into buffer
+ * meson_sm_get_serial - read chip unique serial (OTP data) into buffer
  *
  * @buffer: pointer to buffer
  * @size: buffer size.
+ *
+ * Serial is returned in big-endian order.
+ *
  * @return: zero on success or -errno on failure
  */
 int meson_sm_get_serial(void *buffer, size_t size);
 
+/**
+ * meson_sm_get_chip_id - read Amlogic chip_id
+ *
+ * @chip_id: pointer to buffer capable to hold the struct meson_sm_chip_id
+ *
+ * Amlogic SoCs support 2 versions of chip_id. Function requests the newest
+ * one (v2), but if chip_id v2 is not supported, then secure monitor returns
+ * v1. All differences between v1 and v2 versions are handled by this function
+ * and chip_id is returned in unified format.
+ *
+ * chip_id contains serial, which is returned here in little-endian order.
+ *
+ * @return: 0 on success or -errno on failure
+ */
+int meson_sm_get_chip_id(struct meson_sm_chip_id *chip_id);
+
 enum {
 	REBOOT_REASON_COLD = 0,
 	REBOOT_REASON_NORMAL = 1,