summaryrefslogtreecommitdiffstats
path: root/arch/arm/cpu/armv7/omap4/emif.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm/cpu/armv7/omap4/emif.c')
-rw-r--r--arch/arm/cpu/armv7/omap4/emif.c128
1 files changed, 128 insertions, 0 deletions
diff --git a/arch/arm/cpu/armv7/omap4/emif.c b/arch/arm/cpu/armv7/omap4/emif.c
new file mode 100644
index 0000000..0ddf35f
--- /dev/null
+++ b/arch/arm/cpu/armv7/omap4/emif.c
@@ -0,0 +1,128 @@
+/*
+ * EMIF programming
+ *
+ * (C) Copyright 2010
+ * Texas Instruments, <www.ti.com>
+ *
+ * Aneesh V <aneesh@ti.com>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#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 const*
+ jedec_ac_timings[MAX_NUM_SPEEDBINS] = {
+ &timings_jedec_200_mhz,
+ &timings_jedec_400_mhz
+};
+
+static 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 */
OpenPOWER on IntegriCloud