[U-Boot] [PATCH v3 12/23] tegra: Add EMC support for optimal memory timings
Simon Glass
sjg at chromium.org
Tue Apr 3 01:18:52 CEST 2012
From: Jimmy Zhang <jimmzhang at nvidia.com>
Add support for setting up the memory controller parameters. Boards
can set up an appropriate table in the device tree.
Signed-off-by: Simon Glass <sjg at chromium.org>
---
Changes in v2:
- Add debug() output to EMC
- Move EMC tables to device tree
Changes in v3:
- Support nvidia,use-ram-code binding option for EMC
- Try to return a useful error code when EMC config fails
arch/arm/cpu/armv7/tegra2/Makefile | 1 +
arch/arm/cpu/armv7/tegra2/emc.c | 286 ++++++++++++++++++++++++++++++++
arch/arm/include/asm/arch-tegra2/emc.h | 113 +++++++++++++
include/fdtdec.h | 2 +
lib/fdtdec.c | 2 +
5 files changed, 404 insertions(+), 0 deletions(-)
create mode 100644 arch/arm/cpu/armv7/tegra2/emc.c
create mode 100644 arch/arm/include/asm/arch-tegra2/emc.h
diff --git a/arch/arm/cpu/armv7/tegra2/Makefile b/arch/arm/cpu/armv7/tegra2/Makefile
index e9ac6c9..dcd6329 100644
--- a/arch/arm/cpu/armv7/tegra2/Makefile
+++ b/arch/arm/cpu/armv7/tegra2/Makefile
@@ -34,6 +34,7 @@ LIB = $(obj)lib$(SOC).o
SOBJS := lowlevel_init.o
COBJS-y := ap20.o board.o clock.o funcmux.o pinmux.o sys_info.o timer.o
+COBJS-$(CONFIG_TEGRA_CLOCK_SCALING) += emc.o
COBJS-$(CONFIG_USB_EHCI_TEGRA) += usb.o
COBJS := $(COBJS-y)
diff --git a/arch/arm/cpu/armv7/tegra2/emc.c b/arch/arm/cpu/armv7/tegra2/emc.c
new file mode 100644
index 0000000..c0e5c56
--- /dev/null
+++ b/arch/arm/cpu/armv7/tegra2/emc.c
@@ -0,0 +1,286 @@
+/*
+ * Copyright (c) 2011 The Chromium OS Authors.
+ *
+ * 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 <fdtdec.h>
+#include <asm/io.h>
+#include <asm/arch/ap20.h>
+#include <asm/arch/apb_misc.h>
+#include <asm/arch/clock.h>
+#include <asm/arch/emc.h>
+#include <asm/arch/tegra2.h>
+
+/*
+ * The EMC registers have shadow registers. When the EMC clock is updated
+ * in the clock controller, the shadow registers are copied to the active
+ * registers, allowing glitchless memory bus frequency changes.
+ * This function updates the shadow registers for a new clock frequency,
+ * and relies on the clock lock on the emc clock to avoid races between
+ * multiple frequency changes
+ */
+
+/*
+ * This table defines the ordering of the registers provided to
+ * tegra_set_mmc()
+ * TODO: Convert to fdt version once available
+ */
+static const unsigned long emc_reg_addr[TEGRA_EMC_NUM_REGS] = {
+ 0x2c, /* RC */
+ 0x30, /* RFC */
+ 0x34, /* RAS */
+ 0x38, /* RP */
+ 0x3c, /* R2W */
+ 0x40, /* W2R */
+ 0x44, /* R2P */
+ 0x48, /* W2P */
+ 0x4c, /* RD_RCD */
+ 0x50, /* WR_RCD */
+ 0x54, /* RRD */
+ 0x58, /* REXT */
+ 0x5c, /* WDV */
+ 0x60, /* QUSE */
+ 0x64, /* QRST */
+ 0x68, /* QSAFE */
+ 0x6c, /* RDV */
+ 0x70, /* REFRESH */
+ 0x74, /* BURST_REFRESH_NUM */
+ 0x78, /* PDEX2WR */
+ 0x7c, /* PDEX2RD */
+ 0x80, /* PCHG2PDEN */
+ 0x84, /* ACT2PDEN */
+ 0x88, /* AR2PDEN */
+ 0x8c, /* RW2PDEN */
+ 0x90, /* TXSR */
+ 0x94, /* TCKE */
+ 0x98, /* TFAW */
+ 0x9c, /* TRPAB */
+ 0xa0, /* TCLKSTABLE */
+ 0xa4, /* TCLKSTOP */
+ 0xa8, /* TREFBW */
+ 0xac, /* QUSE_EXTRA */
+ 0x114, /* FBIO_CFG6 */
+ 0xb0, /* ODT_WRITE */
+ 0xb4, /* ODT_READ */
+ 0x104, /* FBIO_CFG5 */
+ 0x2bc, /* CFG_DIG_DLL */
+ 0x2c0, /* DLL_XFORM_DQS */
+ 0x2c4, /* DLL_XFORM_QUSE */
+ 0x2e0, /* ZCAL_REF_CNT */
+ 0x2e4, /* ZCAL_WAIT_CNT */
+ 0x2a8, /* AUTO_CAL_INTERVAL */
+ 0x2d0, /* CFG_CLKTRIM_0 */
+ 0x2d4, /* CFG_CLKTRIM_1 */
+ 0x2d8, /* CFG_CLKTRIM_2 */
+};
+
+struct emc_ctlr *emc_get_controller(const void *blob)
+{
+ fdt_addr_t addr;
+ int node;
+
+ node = fdtdec_next_compatible(blob, 0, COMPAT_NVIDIA_TEGRA20_EMC);
+ if (node > 0) {
+ addr = fdtdec_get_addr(blob, node, "reg");
+ if (addr != FDT_ADDR_T_NONE)
+ return (struct emc_ctlr *)addr;
+ }
+ return NULL;
+}
+
+/* Error codes we use */
+enum {
+ ERR_NO_EMC_NODE = -10,
+ ERR_NO_EMC_REG,
+ ERR_NO_FREQ,
+ ERR_FREQ_NOT_FOUND,
+ ERR_BAD_REGS,
+ ERR_NO_RAM_CODE,
+ ERR_RAM_CODE_NOT_FOUND,
+};
+
+/**
+ * Find EMC tables for the given ram code.
+ *
+ * The tegra EMC binding has two options, one using the ram code and one not.
+ * We detect which is in use by looking for the nvidia,use-ram-code property.
+ * If this is not present, then the EMC tables are directly below 'node',
+ * otherwise we select the correct emc-tables subnode based on the 'ram_code'
+ * value.
+ *
+ * @param blob Device tree blob
+ * @param node EMC node (nvidia,tegra20-emc compatible string)
+ * @param ram_code RAM code to select (0-3, or -1 if unknown)
+ * @return 0 if ok, otherwise a -ve ERR_ code (see enum above)
+ */
+static int find_emc_tables(const void *blob, int node, int ram_code)
+{
+ int need_ram_code;
+ int depth;
+ int offset;
+
+ /* If we are using RAM codes, scan through the tables for our code */
+ need_ram_code = fdtdec_get_bool(blob, node, "nvidia,use-ram-code");
+ if (!need_ram_code)
+ return node;
+ if (ram_code == -1) {
+ debug("%s: RAM code required but not supplied\n", __func__);
+ return ERR_NO_RAM_CODE;
+ }
+
+ offset = node;
+ depth = 0;
+ do {
+ /*
+ * Sadly there is no compatible string so we cannot use
+ * fdtdec_next_compatible_subnode().
+ */
+ offset = fdt_next_node(blob, offset, &depth);
+ if (depth <= 0)
+ break;
+
+ /* Make sure this is a direct subnode */
+ if (depth != 1)
+ continue;
+ if (strcmp("emc-tables", fdt_get_name(blob, offset, NULL)))
+ continue;
+
+ if (fdtdec_get_int(blob, offset, "nvidia,ram-code", -1)
+ == ram_code)
+ return offset;
+ } while (1);
+
+ debug("%s: Could not find tables for RAM code %d\n", __func__,
+ ram_code);
+ return ERR_RAM_CODE_NOT_FOUND;
+}
+
+/**
+ * Decode the EMC node of the device tree, returning a pointer to the emc
+ * controller and the table to be used for the given rate.
+ *
+ * @param blob Device tree blob
+ * @param rate Clock speed of memory controller in Hz (=2x memory bus rate)
+ * @param emcp Returns address of EMC controller registers
+ * @param tablep Returns pointer to table to program into EMC. There are
+ * TEGRA_EMC_NUM_REGS entries, destined for offsets as per the
+ * emc_reg_addr array.
+ * @return 0 if ok, otherwise a -ve error code which will allow someone to
+ * figure out roughly what went wrong by looking at this code.
+ */
+static int decode_emc(const void *blob, unsigned rate, struct emc_ctlr **emcp,
+ const u32 **tablep)
+{
+ struct apb_misc_pp_ctlr *pp =
+ (struct apb_misc_pp_ctlr *)NV_PA_APB_MISC_BASE;
+ int ram_code;
+ int depth;
+ int node;
+
+ ram_code = (readl(&pp->strapping_opt_a) & RAM_CODE_MASK)
+ >> RAM_CODE_SHIFT;
+ /*
+ * The EMC clock rate is twice the bus rate, and the bus rate is
+ * measured in kHz
+ */
+ rate = rate / 2 / 1000;
+
+ node = fdtdec_next_compatible(blob, 0, COMPAT_NVIDIA_TEGRA20_EMC);
+ if (node < 0) {
+ debug("%s: No EMC node found in FDT\n", __func__);
+ return ERR_NO_EMC_NODE;
+ }
+ *emcp = (struct emc_ctlr *)fdtdec_get_addr(blob, node, "reg");
+ if (*emcp == (struct emc_ctlr *)FDT_ADDR_T_NONE) {
+ debug("%s: No EMC node reg property\n", __func__);
+ return ERR_NO_EMC_REG;
+ }
+
+ /* Work out the parent node which contains our EMC tables */
+ node = find_emc_tables(blob, node, ram_code & 3);
+ if (node < 0)
+ return node;
+
+ depth = 0;
+ for (;;) {
+ int node_rate;
+
+ node = fdtdec_next_compatible_subnode(blob, node,
+ COMPAT_NVIDIA_TEGRA20_EMC_TABLE, &depth);
+ if (node < 0)
+ break;
+ node_rate = fdtdec_get_int(blob, node, "clock-frequency", -1);
+ if (node_rate == -1) {
+ debug("%s: Missing clock-frequency\n", __func__);
+ return ERR_NO_FREQ; /* we expect this property */
+ }
+
+ if (node_rate == rate)
+ break;
+ }
+ if (node < 0) {
+ debug("%s: No node found for clock frequency %d\n", __func__,
+ rate);
+ return ERR_FREQ_NOT_FOUND;
+ }
+
+ *tablep = fdtdec_locate_array(blob, node, "nvidia,emc-registers",
+ TEGRA_EMC_NUM_REGS);
+ if (!*tablep) {
+ debug("%s: node '%s' array missing / wrong size\n", __func__,
+ fdt_get_name(blob, node, NULL));
+ return ERR_BAD_REGS;
+ }
+
+ /* All seems well */
+ return 0;
+}
+
+int tegra_set_emc(const void *blob, unsigned rate)
+{
+ struct emc_ctlr *emc;
+ const u32 *table;
+ int err, i;
+
+ err = decode_emc(blob, rate, &emc, &table);
+ if (err) {
+ debug("Warning: no valid EMC (%d), memory timings unset\n",
+ err);
+ return err;
+ }
+
+ debug("%s: Table found, setting EMC values as follows:\n", __func__);
+ for (i = 0; i < TEGRA_EMC_NUM_REGS; i++) {
+ u32 value = fdt32_to_cpu(table[i]);
+ u32 addr = (uintptr_t)emc + emc_reg_addr[i];
+
+ debug(" %#x: %#x\n", addr, value);
+ writel(value, addr);
+ }
+
+ /* trigger emc with new settings */
+ clock_adjust_periph_pll_div(PERIPH_ID_EMC, CLOCK_ID_MEMORY,
+ clock_get_rate(CLOCK_ID_MEMORY), NULL);
+ debug("EMC clock set to %lu\n",
+ clock_get_periph_rate(PERIPH_ID_EMC, CLOCK_ID_MEMORY));
+
+ return 0;
+}
diff --git a/arch/arm/include/asm/arch-tegra2/emc.h b/arch/arm/include/asm/arch-tegra2/emc.h
new file mode 100644
index 0000000..deb3d36
--- /dev/null
+++ b/arch/arm/include/asm/arch-tegra2/emc.h
@@ -0,0 +1,113 @@
+/*
+ * Copyright (c) 2011 The Chromium OS Authors.
+ * (C) Copyright 2010,2011 NVIDIA Corporation <www.nvidia.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
+ */
+
+#ifndef _ARCH_EMC_H_
+#define _ARCH_EMC_H_
+
+#include <asm/types.h>
+
+#define TEGRA_EMC_NUM_REGS 46
+
+/* EMC Registers */
+struct emc_ctlr {
+ u32 cfg; /* 0x00: EMC_CFG */
+ u32 reserved0[3]; /* 0x04 ~ 0x0C */
+ u32 adr_cfg; /* 0x10: EMC_ADR_CFG */
+ u32 adr_cfg1; /* 0x14: EMC_ADR_CFG_1 */
+ u32 reserved1[2]; /* 0x18 ~ 0x18 */
+ u32 refresh_ctrl; /* 0x20: EMC_REFCTRL */
+ u32 pin; /* 0x24: EMC_PIN */
+ u32 timing_ctrl; /* 0x28: EMC_TIMING_CONTROL */
+ u32 rc; /* 0x2C: EMC_RC */
+ u32 rfc; /* 0x30: EMC_RFC */
+ u32 ras; /* 0x34: EMC_RAS */
+ u32 rp; /* 0x38: EMC_RP */
+ u32 r2w; /* 0x3C: EMC_R2W */
+ u32 w2r; /* 0x40: EMC_W2R */
+ u32 r2p; /* 0x44: EMC_R2P */
+ u32 w2p; /* 0x48: EMC_W2P */
+ u32 rd_rcd; /* 0x4C: EMC_RD_RCD */
+ u32 wd_rcd; /* 0x50: EMC_WD_RCD */
+ u32 rrd; /* 0x54: EMC_RRD */
+ u32 rext; /* 0x58: EMC_REXT */
+ u32 wdv; /* 0x5C: EMC_WDV */
+ u32 quse; /* 0x60: EMC_QUSE */
+ u32 qrst; /* 0x64: EMC_QRST */
+ u32 qsafe; /* 0x68: EMC_QSAFE */
+ u32 rdv; /* 0x6C: EMC_RDV */
+ u32 refresh; /* 0x70: EMC_REFRESH */
+ u32 burst_refresh_num; /* 0x74: EMC_BURST_REFRESH_NUM */
+ u32 pdex2wr; /* 0x78: EMC_PDEX2WR */
+ u32 pdex2rd; /* 0x7c: EMC_PDEX2RD */
+ u32 pchg2pden; /* 0x80: EMC_PCHG2PDEN */
+ u32 act2pden; /* 0x84: EMC_ACT2PDEN */
+ u32 ar2pden; /* 0x88: EMC_AR2PDEN */
+ u32 rw2pden; /* 0x8C: EMC_RW2PDEN */
+ u32 txsr; /* 0x90: EMC_TXSR */
+ u32 tcke; /* 0x94: EMC_TCKE */
+ u32 tfaw; /* 0x98: EMC_TFAW */
+ u32 trpab; /* 0x9C: EMC_TRPAB */
+ u32 tclkstable; /* 0xA0: EMC_TCLKSTABLE */
+ u32 tclkstop; /* 0xA4: EMC_TCLKSTOP */
+ u32 trefbw; /* 0xA8: EMC_TREFBW */
+ u32 quse_extra; /* 0xAC: EMC_QUSE_EXTRA */
+ u32 odt_write; /* 0xB0: EMC_ODT_WRITE */
+ u32 odt_read; /* 0xB4: EMC_ODT_READ */
+ u32 reserved2[5]; /* 0xB8 ~ 0xC8 */
+ u32 mrs; /* 0xCC: EMC_MRS */
+ u32 emrs; /* 0xD0: EMC_EMRS */
+ u32 ref; /* 0xD4: EMC_REF */
+ u32 pre; /* 0xD8: EMC_PRE */
+ u32 nop; /* 0xDC: EMC_NOP */
+ u32 self_ref; /* 0xE0: EMC_SELF_REF */
+ u32 dpd; /* 0xE4: EMC_DPD */
+ u32 mrw; /* 0xE8: EMC_MRW */
+ u32 mrr; /* 0xEC: EMC_MRR */
+ u32 reserved3; /* 0xF0: */
+ u32 fbio_cfg1; /* 0xF4: EMC_FBIO_CFG1 */
+ u32 fbio_dqsib_dly; /* 0xF8: EMC_FBIO_DQSIB_DLY */
+ u32 fbio_dqsib_dly_msb; /* 0xFC: EMC_FBIO_DQSIB_DLY_MSG */
+ u32 fbio_spare; /* 0x100: SBIO_SPARE */
+ /* There are more registers ... */
+};
+
+/**
+ * Set up the EMC for the given rate. The timing parameters are retrieved
+ * from the device tree "nvidia,tegra20-emc" node and its
+ * "nvidia,tegra20-emc-table" sub-nodes.
+ *
+ * @param blob Device tree blob
+ * @param rate Clock speed of memory controller in Hz (=2x memory bus rate)
+ * @return 0 if ok, else -ve error code (look in emc.c to decode it)
+ */
+int tegra_set_emc(const void *blob, unsigned rate);
+
+/**
+ * Get a pointer to the EMC controller from the device tree.
+ *
+ * @param blob Device tree blob
+ * @return pointer to EMC controller
+ */
+struct emc_ctlr *emc_get_controller(const void *blob);
+
+#endif
diff --git a/include/fdtdec.h b/include/fdtdec.h
index 0351a25..49251d5 100644
--- a/include/fdtdec.h
+++ b/include/fdtdec.h
@@ -60,6 +60,8 @@ enum fdt_compat_id {
COMPAT_NVIDIA_TEGRA20_USB, /* Tegra2 USB port */
COMPAT_NVIDIA_TEGRA20_I2C, /* Tegra2 i2c */
COMPAT_NVIDIA_TEGRA20_DVC, /* Tegra2 dvc (really just i2c) */
+ COMPAT_NVIDIA_TEGRA20_EMC, /* Tegra2 memory controller */
+ COMPAT_NVIDIA_TEGRA20_EMC_TABLE, /* Tegra2 memory timing table */
COMPAT_COUNT,
};
diff --git a/lib/fdtdec.c b/lib/fdtdec.c
index 76d3808..42c3e89 100644
--- a/lib/fdtdec.c
+++ b/lib/fdtdec.c
@@ -40,6 +40,8 @@ static const char * const compat_names[COMPAT_COUNT] = {
COMPAT(NVIDIA_TEGRA20_USB, "nvidia,tegra20-ehci"),
COMPAT(NVIDIA_TEGRA20_I2C, "nvidia,tegra20-i2c"),
COMPAT(NVIDIA_TEGRA20_DVC, "nvidia,tegra20-i2c-dvc"),
+ COMPAT(NVIDIA_TEGRA20_EMC, "nvidia,tegra20-emc"),
+ COMPAT(NVIDIA_TEGRA20_EMC_TABLE, "nvidia,tegra20-emc-table"),
};
const char *fdtdec_get_compatible(enum fdt_compat_id id)
--
1.7.7.3
More information about the U-Boot
mailing list