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u-boot/arch/arm/mach-omap2/omap4/emif.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* EMIF programming
*
* (C) Copyright 2010
* Texas Instruments, <www.ti.com>
*
* Aneesh V <aneesh@ti.com>
*/
#include <common.h>
#include <asm/emif.h>
#include <asm/arch/sys_proto.h>
#include <asm/utils.h>
#ifndef CONFIG_SYS_EMIF_PRECALCULATED_TIMING_REGS
u32 *const T_num = (u32 *)OMAP_SRAM_SCRATCH_EMIF_T_NUM;
u32 *const T_den = (u32 *)OMAP_SRAM_SCRATCH_EMIF_T_DEN;
#endif
#ifdef CONFIG_SYS_DEFAULT_LPDDR2_TIMINGS
/* Base AC Timing values specified by JESD209-2 for 400MHz operation */
static const struct lpddr2_ac_timings timings_jedec_400_mhz = {
.max_freq = 400000000,
.RL = 6,
.tRPab = 21,
.tRCD = 18,
.tWR = 15,
.tRASmin = 42,
.tRRD = 10,
.tWTRx2 = 15,
.tXSR = 140,
.tXPx2 = 15,
.tRFCab = 130,
.tRTPx2 = 15,
.tCKE = 3,
.tCKESR = 15,
.tZQCS = 90,
.tZQCL = 360,
.tZQINIT = 1000,
.tDQSCKMAXx2 = 11,
.tRASmax = 70,
.tFAW = 50
};
/* Base AC Timing values specified by JESD209-2 for 200 MHz operation */
static const struct lpddr2_ac_timings timings_jedec_200_mhz = {
.max_freq = 200000000,
.RL = 3,
.tRPab = 21,
.tRCD = 18,
.tWR = 15,
.tRASmin = 42,
.tRRD = 10,
.tWTRx2 = 20,
.tXSR = 140,
.tXPx2 = 15,
.tRFCab = 130,
.tRTPx2 = 15,
.tCKE = 3,
.tCKESR = 15,
.tZQCS = 90,
.tZQCL = 360,
.tZQINIT = 1000,
.tDQSCKMAXx2 = 11,
.tRASmax = 70,
.tFAW = 50
};
/*
* Min tCK values specified by JESD209-2
* Min tCK specifies the minimum duration of some AC timing parameters in terms
* of the number of cycles. If the calculated number of cycles based on the
* absolute time value is less than the min tCK value, min tCK value should
* be used instead. This typically happens at low frequencies.
*/
static const struct lpddr2_min_tck min_tck_jedec = {
.tRL = 3,
.tRP_AB = 3,
.tRCD = 3,
.tWR = 3,
.tRAS_MIN = 3,
.tRRD = 2,
.tWTR = 2,
.tXP = 2,
.tRTP = 2,
.tCKE = 3,
.tCKESR = 3,
.tFAW = 8
};
static const struct lpddr2_ac_timings *jedec_ac_timings[MAX_NUM_SPEEDBINS] = {
&timings_jedec_200_mhz,
&timings_jedec_400_mhz
};
const struct lpddr2_device_timings jedec_default_timings = {
.ac_timings = jedec_ac_timings,
.min_tck = &min_tck_jedec
};
void emif_get_device_timings(u32 emif_nr,
const struct lpddr2_device_timings **cs0_device_timings,
const struct lpddr2_device_timings **cs1_device_timings)
{
/* Assume Identical devices on EMIF1 & EMIF2 */
*cs0_device_timings = &jedec_default_timings;
*cs1_device_timings = &jedec_default_timings;
}
#endif /* CONFIG_SYS_DEFAULT_LPDDR2_TIMINGS */