MLK-10361 imx: mx7d arm2: Change to use WDOG_B reset

The default u-boot reset is a internal WDOG reset (warm reset on i.MX6) which
does not have power and DDR reset. So the peripherals and DDR may meet problem.
When using the internal WDOG reset on i.MX7D ARM2 boards,
we meets two DDR issues:

1. On 12x12 ARM2, sometimes the system may hang in DCD because the DDRC Operating Mode
does not become to normal.

2. On 19x19 ARM2, the reset always brings system to USB download because the
DDR3 turns to unstable.

On the i.MX7D ARM2 board, the WDOG_B signal connects to POR_B or PMIC_PWRON. This gives
a chance to use a stronger reset. So in this patch, we set the IOMUX for WDOG_B pin and
enable WDOG_B signal output in WDOG WCR register.

Signed-off-by: Ye.Li <B37916@freescale.com>

5 files changed, 34 insertions, 5 deletions

diff --git a/arch/arm/cpu/armv7/mx7/clock.c b/arch/arm/cpu/armv7/mx7/clock.c
index 00ff806..be42f79 100644
--- a/arch/arm/cpu/armv7/mx7/clock.c
+++ b/arch/arm/cpu/armv7/mx7/clock.c
@@ -707,9 +707,9 @@ static void init_clk_wdog(void)
 
 	/* enable the clock gate */
 	clock_enable(CCGR_WDOG1, 1);
-	clock_enable(CCGR_WDOG2, 2);
-	clock_enable(CCGR_WDOG3, 3);
-	clock_enable(CCGR_WDOG4, 4);
+	clock_enable(CCGR_WDOG2, 1);
+	clock_enable(CCGR_WDOG3, 1);
+	clock_enable(CCGR_WDOG4, 1);
 
 }
 
diff --git a/arch/arm/cpu/armv7/mx7/soc.c b/arch/arm/cpu/armv7/mx7/soc.c
index 9280983..058396e 100644
--- a/arch/arm/cpu/armv7/mx7/soc.c
+++ b/arch/arm/cpu/armv7/mx7/soc.c
@@ -358,6 +358,24 @@ void boot_mode_apply(uint32_t cfg_val)
 	writel(reg, &src_reg->gpr10);
 }
 
+void set_wdog_reset(struct wdog_regs *wdog)
+{
+	u32 reg = readw(&wdog->wcr);
+	/*
+	 * Output WDOG_B signal to reset external pmic or POR_B decided by
+	 * the board desgin. Without external reset, the peripherals/DDR/
+	 * PMIC are not reset, that may cause system working abnormal.
+	 */
+	reg = readw(&wdog->wcr);
+	reg |= 1 << 3;
+	/*
+	 * WDZST bit is write-once only bit. Align this bit in kernel,
+	 * otherwise kernel code will have no chance to set this bit.
+	 */
+	reg |= 1 << 0;
+	writew(reg, &wdog->wcr);
+}
+
 /*
  * cfg_val will be used for
  * Boot_cfg4[7:0]:Boot_cfg3[7:0]:Boot_cfg2[7:0]:Boot_cfg1[7:0]
diff --git a/arch/arm/include/asm/arch-mx7/sys_proto.h b/arch/arm/include/asm/arch-mx7/sys_proto.h
index eb6771b..ac97f5e 100644
--- a/arch/arm/include/asm/arch-mx7/sys_proto.h
+++ b/arch/arm/include/asm/arch-mx7/sys_proto.h
@@ -22,6 +22,7 @@ u32 get_cpu_rev(void);
 
 const char *get_imx_type(u32 imxtype);
 unsigned imx_ddr_size(void);
+void set_wdog_reset(struct wdog_regs *wdog);
 
 int arch_auxiliary_core_up(u32 core_id, u32 boot_private_data);
 int arch_auxiliary_core_check_up(u32 core_id);
diff --git a/board/freescale/mx7d_12x12_lpddr3_arm2/mx7d_12x12_lpddr3_arm2.c b/board/freescale/mx7d_12x12_lpddr3_arm2/mx7d_12x12_lpddr3_arm2.c
index 1dfac25..cd1dabe 100644
--- a/board/freescale/mx7d_12x12_lpddr3_arm2/mx7d_12x12_lpddr3_arm2.c
+++ b/board/freescale/mx7d_12x12_lpddr3_arm2/mx7d_12x12_lpddr3_arm2.c
@@ -261,6 +261,10 @@ static iomux_v3_cfg_t const per_rst_pads[] = {
 	MX7D_PAD_GPIO1_IO03__GPIO1_IO3 | MUX_PAD_CTRL(NO_PAD_CTRL),
 };
 
+static iomux_v3_cfg_t const wdog_pads[] = {
+	MX7D_PAD_GPIO1_IO00__WDOG1_WDOG_B | MUX_PAD_CTRL(NO_PAD_CTRL),
+};
+
 #ifdef CONFIG_FEC_MXC
 static iomux_v3_cfg_t const fec1_pads[] = {
 	MX7D_PAD_GPIO1_IO11__ENET1_MDC | MUX_PAD_CTRL(ENET_PAD_CTRL_MII),
@@ -641,6 +645,10 @@ int board_late_init(void)
 	board_late_mmc_init();
 #endif
 
+	imx_iomux_v3_setup_multiple_pads(wdog_pads, ARRAY_SIZE(wdog_pads));
+
+	set_wdog_reset((struct wdog_regs *)WDOG1_BASE_ADDR);
+
 	return 0;
 }
 
diff --git a/board/freescale/mx7d_19x19_ddr3_arm2/mx7d_19x19_ddr3_arm2.c b/board/freescale/mx7d_19x19_ddr3_arm2/mx7d_19x19_ddr3_arm2.c
index b76760c..5c108f2 100644
--- a/board/freescale/mx7d_19x19_ddr3_arm2/mx7d_19x19_ddr3_arm2.c
+++ b/board/freescale/mx7d_19x19_ddr3_arm2/mx7d_19x19_ddr3_arm2.c
@@ -559,8 +559,6 @@ int board_init(void)
 	/* address of boot parameters */
 	gd->bd->bi_boot_params = PHYS_SDRAM + 0x100;
 
-	imx_iomux_v3_setup_multiple_pads(wdog_pads, ARRAY_SIZE(wdog_pads));
-
 	/* Reset peripherals */
 	imx_iomux_v3_setup_multiple_pads(per_rst_pads, ARRAY_SIZE(per_rst_pads));
 
@@ -653,6 +651,10 @@ int board_late_init(void)
 	board_late_mmc_init();
 #endif
 
+	imx_iomux_v3_setup_multiple_pads(wdog_pads, ARRAY_SIZE(wdog_pads));
+
+	set_wdog_reset((struct wdog_regs *)WDOG1_BASE_ADDR);
+
 	return 0;
 }