arm: mach-k3: Workaround errata ID i2331

Errata doc: https://www.ti.com/lit/pdf/sprz457
Errata ID i2331 CPSW: Device lockup when reading CPSW registers

Details: A device lockup can occur during the second read of any CPSW
subsystem register after any MAIN domain power on reset (POR). A MAIN
domain POR occurs using the hardware MCU_PORz signal, or via software
using CTRLMMR_RST_CTRL.SW_MAIN_POR or CTRLMMR_MCU_RST_CTRL.SW_MAIN_POR.
After these resets, the processor and internal bus structures may get
into a state which is only recoverable with full device reset using
MCU_PORz.
Due to this errata, Ethernet boot should not be used on this device.

Workaround(s): To avoid the lockup, a warm reset should be issued after
a MAIN domain POR and before any access to the CPSW registers. The warm
reset realigns internal clocks and prevents the lockup from happening.
Workaround above errata by calling do_reset() in case of cold boot in
order to trigger warm reset. This needs enabling SYSRESET driver in R5
SPL to enable TI SCI reset driver.

Signed-off-by: Nitin Yadav <n-yadav@ti.com>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Reviewed-by: Bryan Brattlof <bb@ti.com>

diff --git a/arch/arm/mach-k3/am642_init.c b/arch/arm/mach-k3/am642_init.c
index 0c295e7..c871e92 100644 (file)
--- a/arch/arm/mach-k3/am642_init.c
+++ b/arch/arm/mach-k3/am642_init.c
@@ -20,9 +20,15 @@
 #include <dm/pinctrl.h>
 #include <mmc.h>
 #include <dm/root.h>
+#include <command.h>
 
 #define CTRLMMR_MCU_RST_CTRL                   0x04518170
 
+#define CTRLMMR_MCU_RST_SRC                    (MCU_CTRL_MMR0_BASE + 0x18178)
+#define COLD_BOOT                              0
+#define SW_POR_MCU                             BIT(24)
+#define SW_POR_MAIN                            BIT(25)
+
 static void ctrl_mmr_unlock(void)
 {
        /* Unlock all PADCFG_MMR1 module registers */
@@ -164,6 +170,7 @@ void board_init_f(ulong dummy)
 #if defined(CONFIG_K3_LOAD_SYSFW) || defined(CONFIG_K3_AM64_DDRSS) || defined(CONFIG_ESM_K3)
        struct udevice *dev;
        int ret;
+       int rst_src;
 #endif
 
 #if defined(CONFIG_CPU_V7R)
@@ -206,6 +213,32 @@ void board_init_f(ulong dummy)
                        k3_mmc_restart_clock);
 #endif
 
+#if defined(CONFIG_CPU_V7R)
+       /*
+        * Errata ID i2331 CPSW: A device lockup can occur during the second
+        * read of any CPSW subsystem register after any MAIN domain power on
+        * reset (POR). A MAIN domain POR occurs using the hardware MCU_PORz
+        * signal, or via software using CTRLMMR_RST_CTRL.SW_MAIN_POR or
+        * CTRLMMR_MCU_RST_CTRL.SW_MAIN_POR. After these resets, the processor
+        * and internal bus structures may get into a state which is only
+        * recoverable with full device reset using MCU_PORz.
+        * Workaround(s): To avoid the lockup, a warm reset should be issued
+        * after a MAIN domain POR and before any access to the CPSW registers.
+        * The warm reset realigns internal clocks and prevents the lockup from
+        * happening.
+        */
+       ret = uclass_first_device_err(UCLASS_SYSRESET, &dev);
+       if (ret)
+               printf("\n%s:uclass device error [%d]\n",__func__,ret);
+
+       rst_src = readl(CTRLMMR_MCU_RST_SRC);
+       if (rst_src == COLD_BOOT || rst_src & (SW_POR_MCU | SW_POR_MAIN)) {
+               printf("Resetting on cold boot to workaround ErrataID:i2331\n");
+               printf("Please resend tiboot3.bin in case of UART/DFU boot\n");
+               do_reset(NULL, 0, 0, NULL);
+       }
+#endif
+
        /* Output System Firmware version info */
        k3_sysfw_print_ver();
 

diff --git a/configs/am64x_evm_r5_defconfig b/configs/am64x_evm_r5_defconfig
index b75cae6..bb705a1 100644 (file)
--- a/configs/am64x_evm_r5_defconfig
+++ b/configs/am64x_evm_r5_defconfig
@@ -169,3 +169,6 @@ CONFIG_USB_GADGET_VENDOR_NUM=0x0451
 CONFIG_USB_GADGET_PRODUCT_NUM=0x6165
 CONFIG_USB_GADGET_DOWNLOAD=y
 CONFIG_FS_FAT_MAX_CLUSTSIZE=16384
+CONFIG_SYSRESET=y
+CONFIG_SPL_SYSRESET=y
+CONFIG_SYSRESET_TI_SCI=y