]> git.dujemihanovic.xyz Git - u-boot.git/commitdiff
mips: ath79: add support for AR933x SOCs
authorWills Wang <wills.wang@live.com>
Wed, 16 Mar 2016 08:59:53 +0000 (16:59 +0800)
committerDaniel Schwierzeck <daniel.schwierzeck@gmail.com>
Fri, 20 May 2016 23:25:50 +0000 (01:25 +0200)
This patch enable work for ar933x SOC.

Signed-off-by: Wills Wang <wills.wang@live.com>
arch/mips/mach-ath79/Kconfig
arch/mips/mach-ath79/Makefile
arch/mips/mach-ath79/ar933x/Makefile [new file with mode: 0644]
arch/mips/mach-ath79/ar933x/clk.c [new file with mode: 0644]
arch/mips/mach-ath79/ar933x/ddr.c [new file with mode: 0644]
arch/mips/mach-ath79/ar933x/lowlevel_init.S [new file with mode: 0644]

index 7d8ce098be7c81c7670d6f4e4618ba334d4e631c..ab93d92b95c0ec3260f838091801ce46a41f644f 100644 (file)
@@ -4,4 +4,13 @@ menu "QCA/Atheros 7xxx/9xxx platforms"
 config SYS_SOC
        default "ath79"
 
+config SOC_AR933X
+       bool
+       select SUPPORTS_BIG_ENDIAN
+       select SUPPORTS_CPU_MIPS32_R1
+       select SUPPORTS_CPU_MIPS32_R2
+       select MIPS_TUNE_24KC
+       help
+         This supports QCA/Atheros ar933x family SOCs.
+
 endmenu
index 6203cf02420815f62fade0ea36f3d5644d6ec78c..9b9447e207a1d1260f03dd064ecd33be7b6125b1 100644 (file)
@@ -5,3 +5,5 @@
 obj-y += reset.o
 obj-y += cpu.o
 obj-y += dram.o
+
+obj-$(CONFIG_SOC_AR933X)       += ar933x/
\ No newline at end of file
diff --git a/arch/mips/mach-ath79/ar933x/Makefile b/arch/mips/mach-ath79/ar933x/Makefile
new file mode 100644 (file)
index 0000000..fd74f0c
--- /dev/null
@@ -0,0 +1,7 @@
+#
+# SPDX-License-Identifier:     GPL-2.0+
+#
+
+obj-y += clk.o
+obj-y += ddr.o
+obj-y += lowlevel_init.o
diff --git a/arch/mips/mach-ath79/ar933x/clk.c b/arch/mips/mach-ath79/ar933x/clk.c
new file mode 100644 (file)
index 0000000..9fcd496
--- /dev/null
@@ -0,0 +1,89 @@
+/*
+ * Copyright (C) 2015-2016 Wills Wang <wills.wang@live.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <asm/addrspace.h>
+#include <asm/types.h>
+#include <mach/ar71xx_regs.h>
+#include <mach/reset.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+static u32 ar933x_get_xtal(void)
+{
+       u32 val;
+
+       val = get_bootstrap();
+       if (val & AR933X_BOOTSTRAP_REF_CLK_40)
+               return 40000000;
+       else
+               return 25000000;
+}
+
+int get_serial_clock(void)
+{
+       return ar933x_get_xtal();
+}
+
+int get_clocks(void)
+{
+       void __iomem *regs;
+       u32 val, xtal, pll, div;
+
+       regs = map_physmem(AR71XX_PLL_BASE, AR71XX_PLL_SIZE,
+                          MAP_NOCACHE);
+       xtal = ar933x_get_xtal();
+       val = readl(regs + AR933X_PLL_CPU_CONFIG_REG);
+
+       /* VCOOUT = XTAL * DIV_INT */
+       div = (val >> AR933X_PLL_CPU_CONFIG_REFDIV_SHIFT)
+                       & AR933X_PLL_CPU_CONFIG_REFDIV_MASK;
+       pll = xtal / div;
+
+       /* PLLOUT = VCOOUT * (1/2^OUTDIV) */
+       div = (val >> AR933X_PLL_CPU_CONFIG_NINT_SHIFT)
+                       & AR933X_PLL_CPU_CONFIG_NINT_MASK;
+       pll *= div;
+       div = (val >> AR933X_PLL_CPU_CONFIG_OUTDIV_SHIFT)
+                       & AR933X_PLL_CPU_CONFIG_OUTDIV_MASK;
+       if (!div)
+               div = 1;
+       pll >>= div;
+
+       val = readl(regs + AR933X_PLL_CLK_CTRL_REG);
+
+       /* CPU_CLK = PLLOUT / CPU_POST_DIV */
+       div = ((val >> AR933X_PLL_CLK_CTRL_CPU_POST_DIV_SHIFT)
+                       & AR933X_PLL_CLK_CTRL_CPU_POST_DIV_MASK) + 1;
+       gd->cpu_clk = pll / div;
+
+       /* DDR_CLK = PLLOUT / DDR_POST_DIV */
+       div = ((val >> AR933X_PLL_CLK_CTRL_DDR_POST_DIV_SHIFT)
+                       & AR933X_PLL_CLK_CTRL_DDR_POST_DIV_MASK) + 1;
+       gd->mem_clk = pll / div;
+
+       /* AHB_CLK = PLLOUT / AHB_POST_DIV */
+       div = ((val >> AR933X_PLL_CLK_CTRL_AHB_POST_DIV_SHIFT)
+                       & AR933X_PLL_CLK_CTRL_AHB_POST_DIV_MASK) + 1;
+       gd->bus_clk = pll / div;
+
+       return 0;
+}
+
+ulong get_bus_freq(ulong dummy)
+{
+       if (!gd->bus_clk)
+               get_clocks();
+       return gd->bus_clk;
+}
+
+ulong get_ddr_freq(ulong dummy)
+{
+       if (!gd->mem_clk)
+               get_clocks();
+       return gd->mem_clk;
+}
diff --git a/arch/mips/mach-ath79/ar933x/ddr.c b/arch/mips/mach-ath79/ar933x/ddr.c
new file mode 100644 (file)
index 0000000..74e8e80
--- /dev/null
@@ -0,0 +1,333 @@
+/*
+ * Copyright (C) 2015-2016 Wills Wang <wills.wang@live.com>
+ * Based on Atheros LSDK/QSDK
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <asm/addrspace.h>
+#include <asm/types.h>
+#include <mach/ar71xx_regs.h>
+#include <mach/reset.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#define DDR_CTRL_UPD_EMR3S      BIT(5)
+#define DDR_CTRL_UPD_EMR2S      BIT(4)
+#define DDR_CTRL_PRECHARGE      BIT(3)
+#define DDR_CTRL_AUTO_REFRESH   BIT(2)
+#define DDR_CTRL_UPD_EMRS       BIT(1)
+#define DDR_CTRL_UPD_MRS        BIT(0)
+
+#define DDR_REFRESH_EN          (1 << 14)
+#define DDR_REFRESH_M           0x3ff
+#define DDR_REFRESH(x)          ((x) & 0x3ff)
+#define DDR_REFRESH_VAL_25M     (DDR_REFRESH_EN | DDR_REFRESH(390))
+#define DDR_REFRESH_VAL_40M     (DDR_REFRESH_EN | DDR_REFRESH(624))
+
+#define DDR_TRAS_S              0
+#define DDR_TRAS_M              0x1f
+#define DDR_TRAS(x)             ((x) << DDR_TRAS_S)
+#define DDR_TRCD_M              0xf
+#define DDR_TRCD_S              5
+#define DDR_TRCD(x)             ((x) << DDR_TRCD_S)
+#define DDR_TRP_M               0xf
+#define DDR_TRP_S               9
+#define DDR_TRP(x)              ((x) << DDR_TRP_S)
+#define DDR_TRRD_M              0xf
+#define DDR_TRRD_S              13
+#define DDR_TRRD(x)             ((x) << DDR_TRRD_S)
+#define DDR_TRFC_M              0x7f
+#define DDR_TRFC_S              17
+#define DDR_TRFC(x)             ((x) << DDR_TRFC_S)
+#define DDR_TMRD_M              0xf
+#define DDR_TMRD_S              23
+#define DDR_TMRD(x)             ((x) << DDR_TMRD_S)
+#define DDR_CAS_L_M             0x17
+#define DDR_CAS_L_S             27
+#define DDR_CAS_L(x)            (((x) & DDR_CAS_L_M) << DDR_CAS_L_S)
+#define DDR_OPEN                (1 << 30)
+#define DDR_CONF_REG_VAL        (DDR_TRAS(16) | DDR_TRCD(6) | \
+                                DDR_TRP(6) | DDR_TRRD(4) | \
+                                DDR_TRFC(30) | DDR_TMRD(15) | \
+                                DDR_CAS_L(7) | DDR_OPEN)
+
+#define DDR_BURST_LEN_S         0
+#define DDR_BURST_LEN_M         0xf
+#define DDR_BURST_LEN(x)        ((x) << DDR_BURST_LEN_S)
+#define DDR_BURST_TYPE          (1 << 4)
+#define DDR_CNTL_OE_EN          (1 << 5)
+#define DDR_PHASE_SEL           (1 << 6)
+#define DDR_CKE                 (1 << 7)
+#define DDR_TWR_S               8
+#define DDR_TWR_M               0xf
+#define DDR_TWR(x)              ((x) << DDR_TWR_S)
+#define DDR_TRTW_S              12
+#define DDR_TRTW_M              0x1f
+#define DDR_TRTW(x)             ((x) << DDR_TRTW_S)
+#define DDR_TRTP_S              17
+#define DDR_TRTP_M              0xf
+#define DDR_TRTP(x)             ((x) << DDR_TRTP_S)
+#define DDR_TWTR_S              21
+#define DDR_TWTR_M              0x1f
+#define DDR_TWTR(x)             ((x) << DDR_TWTR_S)
+#define DDR_G_OPEN_L_S          26
+#define DDR_G_OPEN_L_M          0xf
+#define DDR_G_OPEN_L(x)         ((x) << DDR_G_OPEN_L_S)
+#define DDR_HALF_WIDTH_LOW      (1 << 31)
+#define DDR_CONF2_REG_VAL       (DDR_BURST_LEN(8) | DDR_CNTL_OE_EN | \
+                                DDR_CKE | DDR_TWR(6) | DDR_TRTW(14) | \
+                                DDR_TRTP(8) | DDR_TWTR(14) | \
+                                DDR_G_OPEN_L(7) | DDR_HALF_WIDTH_LOW)
+
+#define DDR2_CONF_TWL_S         10
+#define DDR2_CONF_TWL_M         0xf
+#define DDR2_CONF_TWL(x)        (((x) & DDR2_CONF_TWL_M) << DDR2_CONF_TWL_S)
+#define DDR2_CONF_ODT           BIT(9)
+#define DDR2_CONF_TFAW_S        2
+#define DDR2_CONF_TFAW_M        0x3f
+#define DDR2_CONF_TFAW(x)       (((x) & DDR2_CONF_TFAW_M) << DDR2_CONF_TFAW_S)
+#define DDR2_CONF_EN            BIT(0)
+#define DDR2_CONF_VAL           (DDR2_CONF_TWL(2) | DDR2_CONF_ODT | \
+                                DDR2_CONF_TFAW(22) | DDR2_CONF_EN)
+
+#define DDR1_EXT_MODE_VAL       0x02
+#define DDR2_EXT_MODE_VAL       0x402
+#define DDR2_EXT_MODE_OCD_VAL   0x382
+#define DDR1_MODE_DLL_VAL       0x133
+#define DDR2_MODE_DLL_VAL       0x100
+#define DDR1_MODE_VAL           0x33
+#define DDR2_MODE_VAL           0xa33
+#define DDR_TAP_VAL0            0x08
+#define DDR_TAP_VAL1            0x09
+
+void ddr_init(void)
+{
+       void __iomem *regs;
+       u32 val;
+
+       regs = map_physmem(AR71XX_DDR_CTRL_BASE, AR71XX_DDR_CTRL_SIZE,
+                          MAP_NOCACHE);
+
+       writel(DDR_CONF_REG_VAL, regs + AR71XX_DDR_REG_CONFIG);
+       writel(DDR_CONF2_REG_VAL, regs + AR71XX_DDR_REG_CONFIG2);
+
+       val = get_bootstrap();
+       if (val & AR933X_BOOTSTRAP_DDR2) {
+               /* AHB maximum timeout */
+               writel(0xfffff, regs + AR933X_DDR_REG_TIMEOUT_MAX);
+
+               /* Enable DDR2 */
+               writel(DDR2_CONF_VAL, regs + AR933X_DDR_REG_DDR2_CONFIG);
+
+               /* Precharge All */
+               writel(DDR_CTRL_PRECHARGE, regs + AR71XX_DDR_REG_CONTROL);
+
+               /* Disable High Temperature Self-Refresh, Full Array */
+               writel(0x00, regs + AR933X_DDR_REG_EMR2);
+
+               /* Extended Mode Register 2 Set (EMR2S) */
+               writel(DDR_CTRL_UPD_EMR2S, regs + AR71XX_DDR_REG_CONTROL);
+
+               writel(0x00, regs + AR933X_DDR_REG_EMR3);
+
+               /* Extended Mode Register 3 Set (EMR3S) */
+               writel(DDR_CTRL_UPD_EMR3S, regs + AR71XX_DDR_REG_CONTROL);
+
+               /* Enable DLL,  Full strength, ODT Disabled */
+               writel(0x00, regs + AR71XX_DDR_REG_EMR);
+
+               /* Extended Mode Register Set (EMRS) */
+               writel(DDR_CTRL_UPD_EMRS, regs + AR71XX_DDR_REG_CONTROL);
+
+               /* Reset DLL */
+               writel(DDR2_MODE_DLL_VAL, regs + AR71XX_DDR_REG_MODE);
+
+               /* Mode Register Set (MRS) */
+               writel(DDR_CTRL_UPD_MRS, regs + AR71XX_DDR_REG_CONTROL);
+
+               /* Precharge All */
+               writel(DDR_CTRL_PRECHARGE, regs + AR71XX_DDR_REG_CONTROL);
+
+               /* Auto Refresh */
+               writel(DDR_CTRL_AUTO_REFRESH, regs + AR71XX_DDR_REG_CONTROL);
+               writel(DDR_CTRL_AUTO_REFRESH, regs + AR71XX_DDR_REG_CONTROL);
+
+               /* Write recovery (WR) 6 clock, CAS Latency 3, Burst Length 8 */
+               writel(DDR2_MODE_VAL, regs + AR71XX_DDR_REG_MODE);
+               /* Mode Register Set (MRS) */
+               writel(DDR_CTRL_UPD_MRS, regs + AR71XX_DDR_REG_CONTROL);
+
+               /* Enable OCD defaults, Enable DLL, Reduced Drive Strength */
+               writel(DDR2_EXT_MODE_OCD_VAL, regs + AR71XX_DDR_REG_EMR);
+
+               /* Extended Mode Register Set (EMRS) */
+               writel(DDR_CTRL_UPD_EMRS, regs + AR71XX_DDR_REG_CONTROL);
+
+               /* OCD exit, Enable DLL, Enable /DQS, Reduced Drive Strength */
+               writel(DDR2_EXT_MODE_VAL, regs + AR71XX_DDR_REG_EMR);
+               /* Extended Mode Register Set (EMRS) */
+               writel(DDR_CTRL_UPD_EMRS, regs + AR71XX_DDR_REG_CONTROL);
+
+               /* Refresh time control */
+               if (val & AR933X_BOOTSTRAP_REF_CLK_40)
+                       writel(DDR_REFRESH_VAL_40M, regs +
+                              AR71XX_DDR_REG_REFRESH);
+               else
+                       writel(DDR_REFRESH_VAL_25M, regs +
+                              AR71XX_DDR_REG_REFRESH);
+
+               /* DQS 0 Tap Control */
+               writel(DDR_TAP_VAL0, regs + AR71XX_DDR_REG_TAP_CTRL0);
+
+               /* DQS 1 Tap Control */
+               writel(DDR_TAP_VAL1, regs + AR71XX_DDR_REG_TAP_CTRL1);
+
+               /* For 16-bit DDR */
+               writel(0xff, regs + AR71XX_DDR_REG_RD_CYCLE);
+       } else {
+               /* AHB maximum timeout */
+               writel(0xfffff, regs + AR933X_DDR_REG_TIMEOUT_MAX);
+
+               /* Precharge All */
+               writel(DDR_CTRL_PRECHARGE, regs + AR71XX_DDR_REG_CONTROL);
+
+               /* Reset DLL, Burst Length 8, CAS Latency 3 */
+               writel(DDR1_MODE_DLL_VAL, regs + AR71XX_DDR_REG_MODE);
+
+               /* Forces an MRS update cycle in DDR */
+               writel(DDR_CTRL_UPD_MRS, regs + AR71XX_DDR_REG_CONTROL);
+
+               /* Enable DLL, Full strength */
+               writel(DDR1_EXT_MODE_VAL, regs + AR71XX_DDR_REG_EMR);
+
+               /* Extended Mode Register Set (EMRS) */
+               writel(DDR_CTRL_UPD_EMRS, regs + AR71XX_DDR_REG_CONTROL);
+
+               /* Precharge All */
+               writel(DDR_CTRL_PRECHARGE, regs + AR71XX_DDR_REG_CONTROL);
+
+               /* Normal DLL, Burst Length 8, CAS Latency 3 */
+               writel(DDR1_MODE_VAL, regs + AR71XX_DDR_REG_MODE);
+
+               /* Mode Register Set (MRS) */
+               writel(DDR_CTRL_UPD_MRS, regs + AR71XX_DDR_REG_CONTROL);
+
+               /* Refresh time control */
+               if (val & AR933X_BOOTSTRAP_REF_CLK_40)
+                       writel(DDR_REFRESH_VAL_40M, regs +
+                              AR71XX_DDR_REG_REFRESH);
+               else
+                       writel(DDR_REFRESH_VAL_25M, regs +
+                              AR71XX_DDR_REG_REFRESH);
+
+               /* DQS 0 Tap Control */
+               writel(DDR_TAP_VAL0, regs + AR71XX_DDR_REG_TAP_CTRL0);
+
+               /* DQS 1 Tap Control */
+               writel(DDR_TAP_VAL1, regs + AR71XX_DDR_REG_TAP_CTRL1);
+
+               /* For 16-bit DDR */
+               writel(0xff, regs + AR71XX_DDR_REG_RD_CYCLE);
+       }
+}
+
+void ddr_tap_tuning(void)
+{
+       void __iomem *regs;
+       u32 *addr_k0, *addr_k1, *addr;
+       u32 val, tap, upper, lower;
+       int i, j, dir, err, done;
+
+       regs = map_physmem(AR71XX_DDR_CTRL_BASE, AR71XX_DDR_CTRL_SIZE,
+                          MAP_NOCACHE);
+
+       /* Init memory pattern */
+       addr = (void *)CKSEG0ADDR(0x2000);
+       for (i = 0; i < 256; i++) {
+               val = 0;
+               for (j = 0; j < 8; j++) {
+                       if (i & (1 << j)) {
+                               if (j % 2)
+                                       val |= 0xffff0000;
+                               else
+                                       val |= 0x0000ffff;
+                       }
+
+                       if (j % 2) {
+                               *addr++ = val;
+                               val = 0;
+                       }
+               }
+       }
+
+       err = 0;
+       done = 0;
+       dir = 1;
+       tap = readl(regs + AR71XX_DDR_REG_TAP_CTRL0);
+       val = tap;
+       while (!done) {
+               err = 0;
+
+               /* Update new DDR tap value */
+               writel(val, regs + AR71XX_DDR_REG_TAP_CTRL0);
+               writel(val, regs + AR71XX_DDR_REG_TAP_CTRL1);
+
+               /* Compare DDR with cache */
+               for (i = 0; i < 2; i++) {
+                       addr_k1 = (void *)CKSEG1ADDR(0x2000);
+                       addr_k0 = (void *)CKSEG0ADDR(0x2000);
+                       addr = (void *)CKSEG0ADDR(0x3000);
+
+                       while (addr_k0 < addr) {
+                               if (*addr_k1++ != *addr_k0++) {
+                                       err = 1;
+                                       break;
+                               }
+                       }
+
+                       if (err)
+                               break;
+               }
+
+               if (err) {
+                       /* Save upper/lower threshold if error  */
+                       if (dir) {
+                               dir = 0;
+                               val--;
+                               upper = val;
+                               val = tap;
+                       } else {
+                               val++;
+                               lower = val;
+                               done = 1;
+                       }
+               } else {
+                       /* Try the next value until limitation */
+                       if (dir) {
+                               if (val < 0x20) {
+                                       val++;
+                               } else {
+                                       dir = 0;
+                                       upper = val;
+                                       val = tap;
+                               }
+                       } else {
+                               if (!val) {
+                                       lower = val;
+                                       done = 1;
+                               } else {
+                                       val--;
+                               }
+                       }
+               }
+       }
+
+       /* compute an intermediate value and write back */
+       val = (upper + lower) / 2;
+       writel(val, regs + AR71XX_DDR_REG_TAP_CTRL0);
+       val++;
+       writel(val, regs + AR71XX_DDR_REG_TAP_CTRL1);
+}
diff --git a/arch/mips/mach-ath79/ar933x/lowlevel_init.S b/arch/mips/mach-ath79/ar933x/lowlevel_init.S
new file mode 100644 (file)
index 0000000..1b847f5
--- /dev/null
@@ -0,0 +1,280 @@
+/*
+ * Copyright (C) 2015-2016 Wills Wang <wills.wang@live.com>
+ * Based on Atheros LSDK/QSDK and u-boot_mod project
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <config.h>
+#include <asm/asm.h>
+#include <asm/regdef.h>
+#include <asm/mipsregs.h>
+#include <asm/addrspace.h>
+#include <mach/ar71xx_regs.h>
+
+#define SET_BIT(val, bit)   ((val) | (1 << (bit)))
+#define SET_PLL_PD(val)     SET_BIT(val, 30)
+#define AHB_DIV_TO_4(val)   SET_BIT(SET_BIT(val, 15), 16)
+#define PLL_BYPASS(val)     SET_BIT(val, 2)
+
+#define MK_PLL_CONF(divint, refdiv, range, outdiv) \
+     (((0x3F & divint) << 10) | \
+     ((0x1F & refdiv) << 16) | \
+     ((0x1 & range)   << 21) | \
+     ((0x7 & outdiv)  << 23) )
+
+#define MK_CLK_CNTL(cpudiv, ddrdiv, ahbdiv) \
+    (((0x3 & (cpudiv - 1)) << 5)  | \
+    ((0x3 & (ddrdiv - 1)) << 10) | \
+    ((0x3 & (ahbdiv - 1)) << 15) )
+
+/*
+ * PLL_CPU_CONFIG_VAL
+ *
+ * Bit30 is set (CPU_PLLPWD = 1 -> power down control for CPU PLL)
+ * After PLL configuration we need to clear this bit
+ *
+ * Values written into CPU PLL Configuration (CPU_PLL_CONFIG)
+ *
+ * bits 10..15  (6bit)  DIV_INT (Integer part of the DIV to CPU PLL)
+ *                      =>  32  (0x20)  VCOOUT = XTAL * DIV_INT
+ * bits 16..20  (5bit)  REFDIV  (Reference clock divider)
+ *                      =>  1   (0x1)   [Must start at values 1]
+ * bits 21      (1bit)  RANGE   (VCO frequency range of the CPU PLL)
+ *                      =>  0   (0x0)   [Doesn't impact clock values]
+ * bits 23..25  (3bit)  OUTDIV  (Ratio between VCO and PLL output)
+ *                      =>  1   (0x1)   [0 is illegal!]
+ *                              PLLOUT = VCOOUT * (1/2^OUTDIV)
+ */
+/* DIV_INT=32 (25MHz*32/2=400MHz), REFDIV=1, RANGE=0, OUTDIV=1 */
+#define PLL_CPU_CONFIG_VAL_40M  MK_PLL_CONF(20, 1, 0, 1)
+/* DIV_INT=20 (40MHz*20/2=400MHz), REFDIV=1, RANGE=0, OUTDIV=1 */
+#define PLL_CPU_CONFIG_VAL_25M  MK_PLL_CONF(32, 1, 0, 1)
+
+/*
+ * PLL_CLK_CONTROL_VAL
+ *
+ * In PLL_CLK_CONTROL_VAL bit 2 is set (BYPASS = 1 -> bypass PLL)
+ * After PLL configuration we need to clear this bit
+ *
+ * Values written into CPU Clock Control Register CLOCK_CONTROL
+ *
+ * bits 2       (1bit)  BYPASS (Bypass PLL. This defaults to 1 for test.
+ *                      Software must enable the CPU PLL for normal and
+ *                      then set this bit to 0)
+ * bits 5..6    (2bit)  CPU_POST_DIV    =>  0   (DEFAULT, Ratio = 1)
+ *                      CPU_CLK = PLLOUT / CPU_POST_DIV
+ * bits 10..11  (2bit)  DDR_POST_DIV    =>  0   (DEFAULT, Ratio = 1)
+ *                      DDR_CLK = PLLOUT / DDR_POST_DIV
+ * bits 15..16  (2bit)  AHB_POST_DIV    =>  1   (DEFAULT, Ratio = 2)
+ *                      AHB_CLK = PLLOUT / AHB_POST_DIV
+ *
+ */
+#define PLL_CLK_CONTROL_VAL MK_CLK_CNTL(1, 1, 2)
+
+    .text
+    .set noreorder
+
+LEAF(lowlevel_init)
+       /* These three WLAN_RESET will avoid original issue */
+       li      t3, 0x03
+1:
+       li      t0, CKSEG1ADDR(AR71XX_RESET_BASE)
+       lw      t1, AR933X_RESET_REG_RESET_MODULE(t0)
+       ori     t1, t1, 0x0800
+       sw      t1, AR933X_RESET_REG_RESET_MODULE(t0)
+       nop
+       lw      t1, AR933X_RESET_REG_RESET_MODULE(t0)
+       li      t2, 0xfffff7ff
+       and     t1, t1, t2
+       sw      t1, AR933X_RESET_REG_RESET_MODULE(t0)
+       nop
+       addi    t3, t3, -1
+       bnez    t3, 1b
+       nop
+
+       li      t2, 0x20
+2:
+       beqz    t2, 1b
+       nop
+       addi    t2, t2, -1
+       lw      t5, AR933X_RESET_REG_BOOTSTRAP(t0)
+       andi    t1, t5, 0x10
+       bnez    t1, 2b
+       nop
+
+       li      t1, 0x02110E
+       sw      t1, AR933X_RESET_REG_BOOTSTRAP(t0)
+       nop
+
+       /* RTC Force Wake */
+       li      t0, CKSEG1ADDR(AR933X_RTC_BASE)
+       li      t1, 0x03
+       sw      t1, AR933X_RTC_REG_FORCE_WAKE(t0)
+       nop
+       nop
+
+       /* RTC Reset */
+       li      t1, 0x00
+       sw      t1, AR933X_RTC_REG_RESET(t0)
+       nop
+       nop
+
+       li      t1, 0x01
+       sw      t1, AR933X_RTC_REG_RESET(t0)
+       nop
+       nop
+
+       /* Wait for RTC in on state */
+1:
+       lw      t1, AR933X_RTC_REG_STATUS(t0)
+       andi    t1, t1, 0x02
+       beqz    t1, 1b
+       nop
+
+       /* Program ki/kd */
+       li      t0, CKSEG1ADDR(AR933X_SRIF_BASE)
+       andi    t1, t5, 0x01            # t5 BOOT_STRAP
+       bnez    t1, 1f
+       nop
+       li      t1, 0x19e82f01
+       b       2f
+       nop
+1:
+       li      t1, 0x18e82f01
+2:
+       sw      t1, AR933X_SRIF_DDR_DPLL2_REG(t0)
+
+       /* Program phase shift */
+       lw      t1, AR933X_SRIF_DDR_DPLL3_REG(t0)
+       li      t2, 0xc07fffff
+       and     t1, t1, t2
+       li      t2, 0x800000
+       or      t1, t1, t2
+       sw      t1, AR933X_SRIF_DDR_DPLL3_REG(t0)
+       nop
+
+       /* in some cases, the SoC doesn't start with higher clock on AHB */
+       li      t0, CKSEG1ADDR(AR71XX_PLL_BASE)
+       li      t1, AHB_DIV_TO_4(PLL_BYPASS(PLL_CLK_CONTROL_VAL))
+       sw      t1, AR933X_PLL_CLK_CTRL_REG(t0)
+       nop
+
+       /* Set SETTLE_TIME in CPU PLL */
+       andi    t1, t5, 0x01            # t5 BOOT_STRAP
+       bnez    t1, 1f
+       nop
+       li      t1, 0x0352
+       b       2f
+       nop
+1:
+       li      t1, 0x0550
+2:
+       sw      t1, AR71XX_PLL_REG_SEC_CONFIG(t0)
+       nop
+
+       /* Set nint, frac, refdiv, outdiv, range according to xtal */
+0:
+       andi    t1, t5, 0x01            # t5 BOOT_STRAP
+       bnez    t1, 1f
+       nop
+       li      t1, SET_PLL_PD(PLL_CPU_CONFIG_VAL_25M)
+       b       2f
+       nop
+1:
+       li      t1, SET_PLL_PD(PLL_CPU_CONFIG_VAL_40M)
+2:
+       sw      t1, AR933X_PLL_CPU_CONFIG_REG(t0)
+       nop
+1:
+       lw      t1, AR933X_PLL_CPU_CONFIG_REG(t0)
+       li      t2, 0x80000000
+       and     t1, t1, t2
+       bnez    t1, 1b
+       nop
+
+       /* Put frac bit19:10 configuration */
+       li      t1, 0x1003E8
+       sw      t1, AR933X_PLL_DITHER_FRAC_REG(t0)
+       nop
+
+       /* Clear PLL power down bit in CPU PLL configuration */
+       andi    t1, t5, 0x01            # t5 BOOT_STRAP
+       bnez    t1, 1f
+       nop
+       li      t1, PLL_CPU_CONFIG_VAL_25M
+       b       2f
+       nop
+1:
+       li      t1, PLL_CPU_CONFIG_VAL_40M
+2:
+       sw      t1, AR933X_PLL_CPU_CONFIG_REG(t0)
+       nop
+
+       /* Wait for PLL update -> bit 31 in CPU_PLL_CONFIG should be 0 */
+1:
+       lw      t1, AR933X_PLL_CPU_CONFIG_REG(t0)
+       li      t2, 0x80000000
+       and     t1, t1, t2
+       bnez    t1, 1b
+       nop
+
+       /* Confirm DDR PLL lock */
+       li      t3, 100
+       li      t4, 0
+
+2:
+       addi    t4, t4, 1
+       bgt     t4, t3, 0b
+       nop
+
+       li      t3, 5
+3:
+       /* Clear do_meas */
+       li      t0, CKSEG1ADDR(AR933X_SRIF_BASE)
+       lw      t1, AR933X_SRIF_DDR_DPLL3_REG(t0)
+       li      t2, 0xBFFFFFFF
+       and     t1, t1, t2
+       sw      t1, AR933X_SRIF_DDR_DPLL3_REG(t0)
+       nop
+
+       li      t2, 10
+1:
+       subu    t2, t2, 1
+       bnez    t2, 1b
+       nop
+
+       /* Set do_meas */
+       li      t2, 0x40000000
+       or      t1, t1, t2
+       sw      t1, AR933X_SRIF_DDR_DPLL3_REG(t0)
+       nop
+
+       /* Check meas_done */
+1:
+       lw      t1, AR933X_SRIF_DDR_DPLL4_REG(t0)
+       andi    t1, t1, 0x8
+       beqz    t1, 1b
+       nop
+
+       lw      t1, AR933X_SRIF_DDR_DPLL3_REG(t0)
+       li      t2, 0x007FFFF8
+       and     t1, t1, t2
+       srl     t1, t1, 3
+       li      t2, 0x4000
+       bgt     t1, t2, 2b
+       nop
+       addi    t3, t3, -1
+       bnez    t3, 3b
+       nop
+
+       /* clear PLL bypass (bit 2) in CPU CLOCK CONTROL register */
+       li      t0, CKSEG1ADDR(AR71XX_PLL_BASE)
+       li      t1, PLL_CLK_CONTROL_VAL
+       sw      t1, AR933X_PLL_CLK_CTRL_REG(t0)
+       nop
+
+       nop
+       jr ra
+       nop
+    END(lowlevel_init)