ddr: add LPDDR2 data from JESD209-2

add LPDDR2 data from the JEDEC spec JESD209-2. The data
includes:

1. Addressing information for LPDDR2 memories of different
   densities and types(S2/S4)
2. AC timing data.

This data will useful for memory controller device drivers.
Right now this is used by the TI EMIF SDRAM controller
driver.

Signed-off-by: Aneesh V <aneesh@ti.com>
Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: Benoit Cousson <b-cousson@ti.com>
[santosh.shilimkar@ti.com: Moved to drivers/memory from drivers/misc]
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

include/memory/jedec_ddr.h

@@ -0,0 +1,175 @@
+/*
+ * Definitions for DDR memories based on JEDEC specs
+ *
+ * Copyright (C) 2012 Texas Instruments, Inc.
+ *
+ * Aneesh V <aneesh@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#ifndef __LINUX_JEDEC_DDR_H
+#define __LINUX_JEDEC_DDR_H
+
+#include <linux/types.h>
+
+/* DDR Densities */
+#define DDR_DENSITY_64Mb	1
+#define DDR_DENSITY_128Mb	2
+#define DDR_DENSITY_256Mb	3
+#define DDR_DENSITY_512Mb	4
+#define DDR_DENSITY_1Gb		5
+#define DDR_DENSITY_2Gb		6
+#define DDR_DENSITY_4Gb		7
+#define DDR_DENSITY_8Gb		8
+#define DDR_DENSITY_16Gb	9
+#define DDR_DENSITY_32Gb	10
+
+/* DDR type */
+#define DDR_TYPE_DDR2		1
+#define DDR_TYPE_DDR3		2
+#define DDR_TYPE_LPDDR2_S4	3
+#define DDR_TYPE_LPDDR2_S2	4
+#define DDR_TYPE_LPDDR2_NVM	5
+
+/* DDR IO width */
+#define DDR_IO_WIDTH_4		1
+#define DDR_IO_WIDTH_8		2
+#define DDR_IO_WIDTH_16		3
+#define DDR_IO_WIDTH_32		4
+
+/* Number of Row bits */
+#define R9			9
+#define R10			10
+#define R11			11
+#define R12			12
+#define R13			13
+#define R14			14
+#define R15			15
+#define R16			16
+
+/* Number of Column bits */
+#define C7			7
+#define C8			8
+#define C9			9
+#define C10			10
+#define C11			11
+#define C12			12
+
+/* Number of Banks */
+#define B1			0
+#define B2			1
+#define B4			2
+#define B8			3
+
+/* Refresh rate in nano-seconds */
+#define T_REFI_15_6		15600
+#define T_REFI_7_8		7800
+#define T_REFI_3_9		3900
+
+/* tRFC values */
+#define T_RFC_90		90000
+#define T_RFC_110		110000
+#define T_RFC_130		130000
+#define T_RFC_160		160000
+#define T_RFC_210		210000
+#define T_RFC_300		300000
+#define T_RFC_350		350000
+
+/* Mode register numbers */
+#define DDR_MR0			0
+#define DDR_MR1			1
+#define DDR_MR2			2
+#define DDR_MR3			3
+#define DDR_MR4			4
+#define DDR_MR5			5
+#define DDR_MR6			6
+#define DDR_MR7			7
+#define DDR_MR8			8
+#define DDR_MR9			9
+#define DDR_MR10		10
+#define DDR_MR11		11
+#define DDR_MR16		16
+#define DDR_MR17		17
+#define DDR_MR18		18
+
+/*
+ * LPDDR2 related defines
+ */
+
+/* MR4 register fields */
+#define MR4_SDRAM_REF_RATE_SHIFT			0
+#define MR4_SDRAM_REF_RATE_MASK				7
+#define MR4_TUF_SHIFT					7
+#define MR4_TUF_MASK					(1 << 7)
+
+/* MR4 SDRAM Refresh Rate field values */
+#define SDRAM_TEMP_NOMINAL				0x3
+#define SDRAM_TEMP_RESERVED_4				0x4
+#define SDRAM_TEMP_HIGH_DERATE_REFRESH			0x5
+#define SDRAM_TEMP_HIGH_DERATE_REFRESH_AND_TIMINGS	0x6
+#define SDRAM_TEMP_VERY_HIGH_SHUTDOWN			0x7
+
+#define NUM_DDR_ADDR_TABLE_ENTRIES			11
+#define NUM_DDR_TIMING_TABLE_ENTRIES			4
+
+/* Structure for DDR addressing info from the JEDEC spec */
+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;
+
+#endif /* __LINUX_JEDEC_DDR_H */