mips: Add basic MediaTek MT7620/88 support
This patch adds basic support for the MediaTek MT7620/88 SoCs. Parts of
the code is copied from the MediaTek GitHub repository:
https://github.com/MediaTek-Labs/linkit-smart-uboot.git
The mt7628a.dtsi file is imported from Linux v4.17.
Support for the LinkIt Smart 7688 module and the Gardena Smart Gateway
both based on the MT7688 will be added in further patches.
Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
diff --git a/arch/mips/mach-mt7620/ddr_calibrate.c b/arch/mips/mach-mt7620/ddr_calibrate.c
new file mode 100644
index 0000000..75763c4
--- /dev/null
+++ b/arch/mips/mach-mt7620/ddr_calibrate.c
@@ -0,0 +1,308 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2018 Stefan Roese <sr@denx.de>
+ *
+ * This code is mostly based on the code extracted from this MediaTek
+ * github repository:
+ *
+ * https://github.com/MediaTek-Labs/linkit-smart-uboot.git
+ *
+ * I was not able to find a specific license or other developers
+ * copyrights here, so I can't add them here.
+ *
+ * Most functions in this file are copied from the MediaTek U-Boot
+ * repository. Without any documentation, it was impossible to really
+ * implement this differently. So its mostly a cleaned-up version of
+ * the original code, with only support for the MT7628 / MT7688 SoC.
+ */
+
+#include <common.h>
+#include <linux/io.h>
+#include <asm/cacheops.h>
+#include <asm/io.h>
+#include "mt76xx.h"
+
+#define NUM_OF_CACHELINE 128
+#define MIN_START 6
+#define MIN_FINE_START 0xf
+#define MAX_START 7
+#define MAX_FINE_START 0x0
+
+#define CPU_FRAC_DIV 1
+
+#if defined(CONFIG_ONBOARD_DDR2_SIZE_256MBIT)
+#define DRAM_BUTTOM 0x02000000
+#endif
+#if defined(CONFIG_ONBOARD_DDR2_SIZE_512MBIT)
+#define DRAM_BUTTOM 0x04000000
+#endif
+#if defined(CONFIG_ONBOARD_DDR2_SIZE_1024MBIT)
+#define DRAM_BUTTOM 0x08000000
+#endif
+#if defined(CONFIG_ONBOARD_DDR2_SIZE_2048MBIT)
+#define DRAM_BUTTOM 0x10000000
+#endif
+
+static inline void cal_memcpy(void *src, void *dst, u32 size)
+{
+ u8 *psrc = (u8 *)src;
+ u8 *pdst = (u8 *)dst;
+ int i;
+
+ for (i = 0; i < size; i++, psrc++, pdst++)
+ *pdst = *psrc;
+}
+
+static inline void cal_memset(void *src, u8 pat, u32 size)
+{
+ u8 *psrc = (u8 *)src;
+ int i;
+
+ for (i = 0; i < size; i++, psrc++)
+ *psrc = pat;
+}
+
+#define pref_op(hint, addr) \
+ __asm__ __volatile__( \
+ ".set push\n" \
+ ".set noreorder\n" \
+ "pref %0, %1\n" \
+ ".set pop\n" \
+ : \
+ : "i" (hint), "R" (*(u8 *)(addr)))
+
+static inline void cal_patgen(u32 start_addr, u32 size, u32 bias)
+{
+ u32 *addr = (u32 *)start_addr;
+ int i;
+
+ for (i = 0; i < size; i++)
+ addr[i] = start_addr + i + bias;
+}
+
+static inline int test_loop(int k, int dqs, u32 test_dqs, u32 *coarse_dqs,
+ u32 offs, u32 pat, u32 val)
+{
+ u32 nc_addr;
+ u32 *c_addr;
+ int i;
+
+ for (nc_addr = 0xa0000000;
+ nc_addr < (0xa0000000 + DRAM_BUTTOM - NUM_OF_CACHELINE * 32);
+ nc_addr += (DRAM_BUTTOM >> 6) + offs) {
+ writel(0x00007474, (void *)MT76XX_MEMCTRL_BASE + 0x64);
+ wmb(); /* Make sure store if finished */
+
+ c_addr = (u32 *)(nc_addr & 0xdfffffff);
+ cal_memset(((u8 *)c_addr), 0x1F, NUM_OF_CACHELINE * 32);
+ cal_patgen(nc_addr, NUM_OF_CACHELINE * 8, pat);
+
+ if (dqs > 0)
+ writel(0x00000074 |
+ (((k == 1) ? coarse_dqs[dqs] : test_dqs) << 12) |
+ (((k == 0) ? val : test_dqs) << 8),
+ (void *)MT76XX_MEMCTRL_BASE + 0x64);
+ else
+ writel(0x00007400 |
+ (((k == 1) ? coarse_dqs[dqs] : test_dqs) << 4) |
+ (((k == 0) ? val : test_dqs) << 0),
+ (void *)MT76XX_MEMCTRL_BASE + 0x64);
+ wmb(); /* Make sure store if finished */
+
+ invalidate_dcache_range((u32)c_addr,
+ (u32)c_addr +
+ NUM_OF_CACHELINE * 32);
+ wmb(); /* Make sure store if finished */
+
+ for (i = 0; i < NUM_OF_CACHELINE * 8; i++) {
+ if (i % 8 == 0)
+ pref_op(0, &c_addr[i]);
+ }
+
+ for (i = 0; i < NUM_OF_CACHELINE * 8; i++) {
+ if (c_addr[i] != nc_addr + i + pat)
+ return -1;
+ }
+ }
+
+ return 0;
+}
+
+void ddr_calibrate(void)
+{
+ u32 min_coarse_dqs[2];
+ u32 max_coarse_dqs[2];
+ u32 min_fine_dqs[2];
+ u32 max_fine_dqs[2];
+ u32 coarse_dqs[2];
+ u32 fine_dqs[2];
+ int reg = 0, ddr_cfg2_reg;
+ int flag;
+ int i, k;
+ int dqs = 0;
+ u32 min_coarse_dqs_bnd, min_fine_dqs_bnd, coarse_dqs_dll, fine_dqs_dll;
+ u32 val;
+ u32 fdiv = 0, frac = 0;
+
+ /* Setup clock to run at full speed */
+ val = readl((void *)MT76XX_DYN_CFG0_REG);
+ fdiv = (u32)((val >> 8) & 0x0F);
+ if (CPU_FRAC_DIV < 1 || CPU_FRAC_DIV > 10)
+ frac = val & 0x0f;
+ else
+ frac = CPU_FRAC_DIV;
+
+ while (frac < fdiv) {
+ val = readl((void *)MT76XX_DYN_CFG0_REG);
+ fdiv = (val >> 8) & 0x0f;
+ fdiv--;
+ val &= ~(0x0f << 8);
+ val |= (fdiv << 8);
+ writel(val, (void *)MT76XX_DYN_CFG0_REG);
+ udelay(500);
+ val = readl((void *)MT76XX_DYN_CFG0_REG);
+ fdiv = (val >> 8) & 0x0f;
+ }
+
+ clrbits_le32((void *)MT76XX_MEMCTRL_BASE + 0x10, BIT(4));
+ ddr_cfg2_reg = readl((void *)MT76XX_MEMCTRL_BASE + 0x48);
+ clrbits_le32((void *)MT76XX_MEMCTRL_BASE + 0x48,
+ (0x3 << 28) | (0x3 << 26));
+
+ min_coarse_dqs[0] = MIN_START;
+ min_coarse_dqs[1] = MIN_START;
+ min_fine_dqs[0] = MIN_FINE_START;
+ min_fine_dqs[1] = MIN_FINE_START;
+ max_coarse_dqs[0] = MAX_START;
+ max_coarse_dqs[1] = MAX_START;
+ max_fine_dqs[0] = MAX_FINE_START;
+ max_fine_dqs[1] = MAX_FINE_START;
+ dqs = 0;
+
+ /* Add by KP, DQS MIN boundary */
+ reg = readl((void *)MT76XX_MEMCTRL_BASE + 0x20);
+ coarse_dqs_dll = (reg & 0xf00) >> 8;
+ fine_dqs_dll = (reg & 0xf0) >> 4;
+ if (coarse_dqs_dll <= 8)
+ min_coarse_dqs_bnd = 8 - coarse_dqs_dll;
+ else
+ min_coarse_dqs_bnd = 0;
+
+ if (fine_dqs_dll <= 8)
+ min_fine_dqs_bnd = 8 - fine_dqs_dll;
+ else
+ min_fine_dqs_bnd = 0;
+ /* DQS MIN boundary */
+
+DQS_CAL:
+
+ for (k = 0; k < 2; k++) {
+ u32 test_dqs;
+
+ if (k == 0)
+ test_dqs = MAX_START;
+ else
+ test_dqs = MAX_FINE_START;
+
+ do {
+ flag = test_loop(k, dqs, test_dqs, max_coarse_dqs,
+ 0x400, 0x3, 0xf);
+ if (flag == -1)
+ break;
+
+ test_dqs++;
+ } while (test_dqs <= 0xf);
+
+ if (k == 0) {
+ max_coarse_dqs[dqs] = test_dqs;
+ } else {
+ test_dqs--;
+
+ if (test_dqs == MAX_FINE_START - 1) {
+ max_coarse_dqs[dqs]--;
+ max_fine_dqs[dqs] = 0xf;
+ } else {
+ max_fine_dqs[dqs] = test_dqs;
+ }
+ }
+ }
+
+ for (k = 0; k < 2; k++) {
+ u32 test_dqs;
+
+ if (k == 0)
+ test_dqs = MIN_START;
+ else
+ test_dqs = MIN_FINE_START;
+
+ do {
+ flag = test_loop(k, dqs, test_dqs, min_coarse_dqs,
+ 0x480, 0x1, 0x0);
+ if (k == 0) {
+ if (flag == -1 ||
+ test_dqs == min_coarse_dqs_bnd)
+ break;
+
+ test_dqs--;
+
+ if (test_dqs < min_coarse_dqs_bnd)
+ break;
+ } else {
+ if (flag == -1) {
+ test_dqs++;
+ break;
+ } else if (test_dqs == min_fine_dqs_bnd) {
+ break;
+ }
+
+ test_dqs--;
+
+ if (test_dqs < min_fine_dqs_bnd)
+ break;
+ }
+ } while (test_dqs >= 0);
+
+ if (k == 0) {
+ min_coarse_dqs[dqs] = test_dqs;
+ } else {
+ if (test_dqs == MIN_FINE_START + 1) {
+ min_coarse_dqs[dqs]++;
+ min_fine_dqs[dqs] = 0x0;
+ } else {
+ min_fine_dqs[dqs] = test_dqs;
+ }
+ }
+ }
+
+ if (dqs == 0) {
+ dqs = 1;
+ goto DQS_CAL;
+ }
+
+ for (i = 0; i < 2; i++) {
+ u32 temp;
+
+ coarse_dqs[i] = (max_coarse_dqs[i] + min_coarse_dqs[i]) >> 1;
+ temp =
+ (((max_coarse_dqs[i] + min_coarse_dqs[i]) % 2) * 4) +
+ ((max_fine_dqs[i] + min_fine_dqs[i]) >> 1);
+ if (temp >= 0x10) {
+ coarse_dqs[i]++;
+ fine_dqs[i] = (temp - 0x10) + 0x8;
+ } else {
+ fine_dqs[i] = temp;
+ }
+ }
+ reg = (coarse_dqs[1] << 12) | (fine_dqs[1] << 8) |
+ (coarse_dqs[0] << 4) | fine_dqs[0];
+
+ clrbits_le32((void *)MT76XX_MEMCTRL_BASE + 0x10, BIT(4));
+ writel(reg, (void *)MT76XX_MEMCTRL_BASE + 0x64);
+ writel(ddr_cfg2_reg, (void *)MT76XX_MEMCTRL_BASE + 0x48);
+ setbits_le32((void *)MT76XX_MEMCTRL_BASE + 0x10, BIT(4));
+
+ for (i = 0; i < 2; i++)
+ debug("[%02X%02X%02X%02X]", min_coarse_dqs[i],
+ min_fine_dqs[i], max_coarse_dqs[i], max_fine_dqs[i]);
+ debug("\nDDR Calibration DQS reg = %08X\n", reg);
+}