1 /* 2 * EMIF programming 3 * 4 * (C) Copyright 2010 5 * Texas Instruments, <www.ti.com> 6 * 7 * Aneesh V <aneesh@ti.com> 8 * 9 * SPDX-License-Identifier: GPL-2.0+ 10 */ 11 12 #include <common.h> 13 #include <asm/emif.h> 14 #include <asm/arch/sys_proto.h> 15 #include <asm/utils.h> 16 17 #ifndef CONFIG_SYS_EMIF_PRECALCULATED_TIMING_REGS 18 u32 *const T_num = (u32 *)OMAP_SRAM_SCRATCH_EMIF_T_NUM; 19 u32 *const T_den = (u32 *)OMAP_SRAM_SCRATCH_EMIF_T_DEN; 20 #endif 21 22 #ifdef CONFIG_SYS_DEFAULT_LPDDR2_TIMINGS 23 /* Base AC Timing values specified by JESD209-2 for 400MHz operation */ 24 static const struct lpddr2_ac_timings timings_jedec_400_mhz = { 25 .max_freq = 400000000, 26 .RL = 6, 27 .tRPab = 21, 28 .tRCD = 18, 29 .tWR = 15, 30 .tRASmin = 42, 31 .tRRD = 10, 32 .tWTRx2 = 15, 33 .tXSR = 140, 34 .tXPx2 = 15, 35 .tRFCab = 130, 36 .tRTPx2 = 15, 37 .tCKE = 3, 38 .tCKESR = 15, 39 .tZQCS = 90, 40 .tZQCL = 360, 41 .tZQINIT = 1000, 42 .tDQSCKMAXx2 = 11, 43 .tRASmax = 70, 44 .tFAW = 50 45 }; 46 47 /* Base AC Timing values specified by JESD209-2 for 200 MHz operation */ 48 static const struct lpddr2_ac_timings timings_jedec_200_mhz = { 49 .max_freq = 200000000, 50 .RL = 3, 51 .tRPab = 21, 52 .tRCD = 18, 53 .tWR = 15, 54 .tRASmin = 42, 55 .tRRD = 10, 56 .tWTRx2 = 20, 57 .tXSR = 140, 58 .tXPx2 = 15, 59 .tRFCab = 130, 60 .tRTPx2 = 15, 61 .tCKE = 3, 62 .tCKESR = 15, 63 .tZQCS = 90, 64 .tZQCL = 360, 65 .tZQINIT = 1000, 66 .tDQSCKMAXx2 = 11, 67 .tRASmax = 70, 68 .tFAW = 50 69 }; 70 71 /* 72 * Min tCK values specified by JESD209-2 73 * Min tCK specifies the minimum duration of some AC timing parameters in terms 74 * of the number of cycles. If the calculated number of cycles based on the 75 * absolute time value is less than the min tCK value, min tCK value should 76 * be used instead. This typically happens at low frequencies. 77 */ 78 static const struct lpddr2_min_tck min_tck_jedec = { 79 .tRL = 3, 80 .tRP_AB = 3, 81 .tRCD = 3, 82 .tWR = 3, 83 .tRAS_MIN = 3, 84 .tRRD = 2, 85 .tWTR = 2, 86 .tXP = 2, 87 .tRTP = 2, 88 .tCKE = 3, 89 .tCKESR = 3, 90 .tFAW = 8 91 }; 92 93 static const struct lpddr2_ac_timings const* 94 jedec_ac_timings[MAX_NUM_SPEEDBINS] = { 95 &timings_jedec_200_mhz, 96 &timings_jedec_400_mhz 97 }; 98 99 const struct lpddr2_device_timings jedec_default_timings = { 100 .ac_timings = jedec_ac_timings, 101 .min_tck = &min_tck_jedec 102 }; 103 104 void emif_get_device_timings(u32 emif_nr, 105 const struct lpddr2_device_timings **cs0_device_timings, 106 const struct lpddr2_device_timings **cs1_device_timings) 107 { 108 /* Assume Identical devices on EMIF1 & EMIF2 */ 109 *cs0_device_timings = &jedec_default_timings; 110 *cs1_device_timings = &jedec_default_timings; 111 } 112 #endif /* CONFIG_SYS_DEFAULT_LPDDR2_TIMINGS */ 113