From 9ffa7a35ef940b27813c11f68eb28a6b82696915 Mon Sep 17 00:00:00 2001 From: Purna Chandra Mandal Date: Thu, 28 Jan 2016 15:30:15 +0530 Subject: drivers: ddr: Add DDR2 SDRAM controller driver for Microchip PIC32. This driver initializes PIC32 DDR2 SDRAM controller and internal DDR2 Phy module. DDR2 controller operates in half-rate mode (upto 533MHZ frequency). Signed-off-by: Paul Thacker Signed-off-by: Purna Chandra Mandal Reviewed-by: Daniel Schwierzeck Reviewed-by: Tom Rini Reviewed-by: Simon Glass --- drivers/ddr/microchip/ddr2_timing.h | 65 +++++++++++++++++++++++++++++++++++++ 1 file changed, 65 insertions(+) create mode 100644 drivers/ddr/microchip/ddr2_timing.h (limited to 'drivers/ddr/microchip/ddr2_timing.h') diff --git a/drivers/ddr/microchip/ddr2_timing.h b/drivers/ddr/microchip/ddr2_timing.h new file mode 100644 index 00000000000..5895f9d5928 --- /dev/null +++ b/drivers/ddr/microchip/ddr2_timing.h @@ -0,0 +1,65 @@ +/* + * (c) 2015 Purna Chandra Mandal + * + * SPDX-License-Identifier: GPL-2.0+ + * + */ + +#ifndef __MICROCHIP_DDR2_TIMING_H +#define __MICROCHIP_DDR2_TIMING_H + +/* MPLL freq is 400MHz */ +#define T_CK 2500 /* 2500 psec */ +#define T_CK_CTRL (T_CK * 2) + +/* Burst length in cycles */ +#define BL 2 +/* default CAS latency for all speed grades */ +#define RL 5 +/* default write latency for all speed grades = CL-1 */ +#define WL 4 + +/* From Micron MT47H64M16HR-3 data sheet */ +#define T_RFC_MIN 127500 /* psec */ +#define T_WR 15000 /* psec */ +#define T_RP 12500 /* psec */ +#define T_RCD 12500 /* psec */ +#define T_RRD 7500 /* psec */ +/* T_RRD_TCK is minimum of 2 clk periods, regardless of freq */ +#define T_RRD_TCK 2 +#define T_WTR 7500 /* psec */ +/* T_WTR_TCK is minimum of 2 clk periods, regardless of freq */ +#define T_WTR_TCK 2 +#define T_RTP 7500 /* psec */ +#define T_RTP_TCK (BL / 2) +#define T_XP_TCK 2 /* clocks */ +#define T_CKE_TCK 3 /* clocks */ +#define T_XSNR (T_RFC_MIN + 10000) /* psec */ +#define T_DLLK 200 /* clocks */ +#define T_RAS_MIN 45000 /* psec */ +#define T_RC 57500 /* psec */ +#define T_FAW 35000 /* psec */ +#define T_MRD_TCK 2 /* clocks */ +#define T_RFI 7800000 /* psec */ + +/* DDR Addressing */ +#define COL_BITS 10 +#define BA_BITS 3 +#define ROW_BITS 13 +#define CS_BITS 1 + +/* DDR Addressing scheme: {CS, ROW, BA, COL} */ +#define COL_HI_RSHFT 0 +#define COL_HI_MASK 0 +#define COL_LO_MASK ((1 << COL_BITS) - 1) + +#define BA_RSHFT COL_BITS +#define BA_MASK ((1 << BA_BITS) - 1) + +#define ROW_ADDR_RSHIFT (BA_RSHFT + BA_BITS) +#define ROW_ADDR_MASK ((1 << ROW_BITS) - 1) + +#define CS_ADDR_RSHIFT 0 +#define CS_ADDR_MASK 0 + +#endif /* __MICROCHIP_DDR2_TIMING_H */ -- cgit v1.2.3