--- /dev/null
+/*
+ * Copyright (c) 2011 The Chromium OS Authors.
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <fdtdec.h>
+#include <asm/io.h>
+#include <asm/arch-tegra/ap.h>
+#include <asm/arch-tegra/apb_misc.h>
+#include <asm/arch/clock.h>
+#include <asm/arch/emc.h>
+#include <asm/arch/tegra.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 = NULL;
+ 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;
+}
Code Review / kvmfornfv.git / blobdiff