drivers/memory/jedec_ddr.h

Source file repositories/reference/linux-study-clean/drivers/memory/jedec_ddr.h

File Facts

System
Linux kernel
Corpus path
drivers/memory/jedec_ddr.h
Extension
.h
Size
5604 bytes
Lines
281
Domain
Driver Families
Bucket
drivers/memory
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

struct lpddr2_addressing {
	u32 num_banks;
	u32 tREFI_ns;
	u32 tRFCab_ps;
};

/*
 * Structure for timings from the LPDDR2 datasheet
 * All parameters are in pico seconds(ps) unless explicitly indicated
 * with a suffix like tRAS_max_ns below
 */
struct lpddr2_timings {
	u32 max_freq;
	u32 min_freq;
	u32 tRPab;
	u32 tRCD;
	u32 tWR;
	u32 tRAS_min;
	u32 tRRD;
	u32 tWTR;
	u32 tXP;
	u32 tRTP;
	u32 tCKESR;
	u32 tDQSCK_max;
	u32 tDQSCK_max_derated;
	u32 tFAW;
	u32 tZQCS;
	u32 tZQCL;
	u32 tZQinit;
	u32 tRAS_max_ns;
};

/*
 * Min value for some parameters in terms of number of tCK cycles(nCK)
 * Please set to zero parameters that are not valid for a given memory
 * type
 */
struct lpddr2_min_tck {
	u32 tRPab;
	u32 tRCD;
	u32 tWR;
	u32 tRASmin;
	u32 tRRD;
	u32 tWTR;
	u32 tXP;
	u32 tRTP;
	u32 tCKE;
	u32 tCKESR;
	u32 tFAW;
};

extern const struct lpddr2_addressing
	lpddr2_jedec_addressing_table[NUM_DDR_ADDR_TABLE_ENTRIES];
extern const struct lpddr2_timings
	lpddr2_jedec_timings[NUM_DDR_TIMING_TABLE_ENTRIES];
extern const struct lpddr2_min_tck lpddr2_jedec_min_tck;

/* Structure of MR8 */
union lpddr2_basic_config4 {
	u32 value;

	struct {
		unsigned int arch_type : 2;
		unsigned int density : 4;
		unsigned int io_width : 2;
	} __packed;
};

/*
 * Structure for information about LPDDR2 chip. All parameters are
 * matching raw values of standard mode register bitfields or set to
 * -ENOENT if info unavailable.
 */
struct lpddr2_info {
	int arch_type;
	int density;
	int io_width;
	int manufacturer_id;
	int revision_id1;
	int revision_id2;
};

const char *lpddr2_jedec_manufacturer(unsigned int manufacturer_id);

/*
 * Structure for timings for LPDDR3 based on LPDDR2 plus additional fields.
 * All parameters are in pico seconds(ps) excluding max_freq, min_freq which
 * are in Hz.
 */
struct lpddr3_timings {

Annotation

Implementation Notes