Merge "fix(st): manage UART clock and reset only in BL2" into integration
diff --git a/docs/plat/allwinner.rst b/docs/plat/allwinner.rst
index b696989..3e9ce51 100644
--- a/docs/plat/allwinner.rst
+++ b/docs/plat/allwinner.rst
@@ -8,24 +8,67 @@
 Building TF-A
 -------------
 
-To build for machines with an A64 or H5 SoC:
+There is one build target per supported SoC:
+
++------+-------------------+
+| SoC  | TF-A build target |
++======+===================+
+| A64  | sun50i_a64        |
++------+-------------------+
+| H5   | sun50i_a64        |
++------+-------------------+
+| H6   | sun50i_h6         |
++------+-------------------+
+| H616 | sun50i_h616       |
++------+-------------------+
+| H313 | sun50i_h616       |
++------+-------------------+
+| R329 | sun50i_r329       |
++------+-------------------+
+
+To build with the default settings for a particular SoC:
 
 .. code:: shell
 
-    make CROSS_COMPILE=aarch64-linux-gnu- PLAT=sun50i_a64 DEBUG=1 bl31
+    make CROSS_COMPILE=aarch64-linux-gnu- PLAT=<build target> DEBUG=1
 
-To build for machines with an H6 SoC:
+So for instance to build for a board with the Allwinner A64 SoC::
 
-.. code:: shell
+    make CROSS_COMPILE=aarch64-linux-gnu- PLAT=sun50i_a64 DEBUG=1
 
-    make CROSS_COMPILE=aarch64-linux-gnu- PLAT=sun50i_h6 DEBUG=1 bl31
+Platform-specific build options
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-To build for machines with an H616 or H313 SoC:
+The default build options should generate a working firmware image. There are
+some build options that allow to fine-tune the firmware, or to disable support
+for optional features.
 
-.. code:: shell
+-  ``SUNXI_PSCI_USE_NATIVE`` : Support direct control of the CPU cores powerdown
+   and powerup sequence by BL31. This requires either support for a code snippet
+   to be loaded into the ARISC SCP (A64, H5), or the power sequence control
+   registers to be programmed directly (H6, H616). This supports only basic
+   control, like core on/off and system off/reset.
+   This option defaults to 1. If an active SCP supporting the SCPI protocol
+   is detected at runtime, this control scheme will be ignored, and SCPI
+   will be used instead, unless support has been explicitly disabled.
 
-    make CROSS_COMPILE=aarch64-linux-gnu- PLAT=sun50i_h616 DEBUG=1 bl31
+-  ``SUNXI_PSCI_USE_SCPI`` : Support control of the CPU cores powerdown and
+   powerup sequence by talking to the SCP processor via the SCPI protocol.
+   This allows more advanced power saving techniques, like suspend to RAM.
+   This option defaults to 1 on SoCs that feature an SCP. If no SCP firmware
+   using the SCPI protocol is detected, the native sequence will be used
+   instead. If both native and SCPI methods are included, SCPI will be favoured
+   if SCP support is detected.
 
+-  ``SUNXI_SETUP_REGULATORS`` : On SoCs that typically ship with a PMIC
+   power management controller, BL31 tries to set up all needed power rails,
+   programming them to their respective voltages. That allows bootloader
+   software like U-Boot to ignore power control via the PMIC.
+   This setting defaults to 1. In some situations that enables too many
+   regulators, or some regulators need to be enabled in a very specific
+   sequence. To avoid problems with those boards, ``SUNXI_SETUP_REGULATORS``
+   can bet set to ``0`` on the build command line, to skip the PMIC setup
+   entirely. Any bootloader or OS would need to setup the PMIC on its own then.
 
 Installation
 ------------
diff --git a/lib/cpus/aarch64/rainier.S b/lib/cpus/aarch64/rainier.S
index 3017a50..584ab97 100644
--- a/lib/cpus/aarch64/rainier.S
+++ b/lib/cpus/aarch64/rainier.S
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020, Arm Limited. All rights reserved.
+ * Copyright (c) 2020-2022, Arm Limited. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -41,6 +41,40 @@
 	ret
 endfunc rainier_disable_speculative_loads
 
+	/* --------------------------------------------------
+	 * Errata Workaround for Neoverse N1 Errata #1868343.
+	 * This applies to revision <= r4p0 of Neoverse N1.
+	 * This workaround is the same as the workaround for
+	 * errata 1262606 and 1275112 but applies to a wider
+	 * revision range.
+	 * Rainier R0P0 is based on Neoverse N1 R4P0 so the
+	 * workaround checks for r0p0 version of Rainier CPU.
+	 * Inputs:
+	 * x0: variant[4:7] and revision[0:3] of current cpu.
+	 * Shall clobber: x0, x1 & x17
+	 * --------------------------------------------------
+	 */
+func errata_n1_1868343_wa
+	/*
+	 * Compare x0 against revision r4p0
+	 */
+	mov	x17, x30
+	bl	check_errata_1868343
+	cbz	x0, 1f
+	mrs	x1, RAINIER_CPUACTLR_EL1
+	orr	x1, x1, RAINIER_CPUACTLR_EL1_BIT_13
+	msr	RAINIER_CPUACTLR_EL1, x1
+	isb
+1:
+	ret	x17
+endfunc errata_n1_1868343_wa
+
+func check_errata_1868343
+	/* Applies to r0p0 of Rainier CPU */
+	mov	x1, #0x00
+	b	cpu_rev_var_ls
+endfunc check_errata_1868343
+
 func rainier_reset_func
 	mov	x19, x30
 
@@ -55,6 +89,11 @@
 	bl	cpu_get_rev_var
 	mov	x18, x0
 
+#if ERRATA_N1_1868343
+	mov	x0, x18
+	bl	errata_n1_1868343_wa
+#endif
+
 #if ENABLE_AMU
 	/* Make sure accesses from EL0/EL1 and EL2 are not trapped to EL3 */
 	mrs	x0, actlr_el3
@@ -101,6 +140,12 @@
 	bl	cpu_get_rev_var
 	mov	x8, x0
 
+	/*
+	 * Report all errata. The revision-variant information is passed to
+	 * checking functions of each errata.
+	 */
+	report_errata ERRATA_N1_1868343, rainier, 1868343
+
 	ldp	x8, x30, [sp], #16
 	ret
 endfunc rainier_errata_report
diff --git a/plat/arm/board/morello/platform.mk b/plat/arm/board/morello/platform.mk
index 26a1911..86047e3 100644
--- a/plat/arm/board/morello/platform.mk
+++ b/plat/arm/board/morello/platform.mk
@@ -83,6 +83,9 @@
 
 override ARM_PLAT_MT			:=	1
 
+# Errata workarounds:
+ERRATA_N1_1868343			:=	1
+
 # Select SCMI/SDS drivers instead of SCPI/BOM driver for communicating with the
 # SCP during power management operations and for SCP RAM Firmware transfer.
 CSS_USE_SCMI_SDS_DRIVER			:=	1