From 92e80162f313aacdbbc13aef233b5d4a6df41c5e Mon Sep 17 00:00:00 2001
From: Kyle Evans <kevans@FreeBSD.org>
Date: Sun, 7 Jan 2018 04:59:28 +0000
Subject: [PATCH] aw_sid(4): Add support for Allwinner H3

The sid controller on the H3 is generally identical in location, size, and
efuse offset to the a64 and the a83t. The main difference is that the H3 has
a silicon bug that sometimes causes the rootkey (at least) to be garbled
unless first read by the prctl registers.

This device is currently not in our DTS and, as of now, is not yet present
in mainline Linux DTS.

Tested on:	OrangePi One
---
 share/man/man4/aw_sid.4    |  4 +++-
 sys/arm/allwinner/aw_sid.c | 30 ++++++++++++++++++++++++++++++
 2 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/share/man/man4/aw_sid.4 b/share/man/man4/aw_sid.4
index 1ac6c62fcc6..7a55f4168f2 100644
--- a/share/man/man4/aw_sid.4
+++ b/share/man/man4/aw_sid.4
@@ -25,7 +25,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd January 2, 2018
+.Dd January 6, 2018
 .Dt AW_SID 4
 .Os
 .Sh NAME
@@ -52,6 +52,8 @@ allwinner,sun7i-a20-sid
 allwinner,sun50i-a64-sid
 .It
 allwinner,sun8i-a83t-sid
+.It
+allwinner,sun8i-h3-sid
 .El
 .Sh SYSCTL VARIABLES
 The following read-only variables are available via
diff --git a/sys/arm/allwinner/aw_sid.c b/sys/arm/allwinner/aw_sid.c
index 6bae8e6d55a..8943818f525 100644
--- a/sys/arm/allwinner/aw_sid.c
+++ b/sys/arm/allwinner/aw_sid.c
@@ -67,36 +67,51 @@ __FBSDID("$FreeBSD$");
 #define	ROOT_KEY_SIZE		4
 
 struct aw_sid_conf {
+	bus_size_t	efuse_size;
 	bus_size_t	rootkey_offset;
 	bool		has_prctl;
 	bool		has_thermal;
+	bool		requires_prctl_read;
 };
 
 static const struct aw_sid_conf a10_conf = {
+	.efuse_size = 0x10,
 	.rootkey_offset = 0,
 };
 
 static const struct aw_sid_conf a20_conf = {
+	.efuse_size = 0x10,
 	.rootkey_offset = 0,
 };
 
 static const struct aw_sid_conf a64_conf = {
+	.efuse_size = 0x100,
 	.rootkey_offset = SID_SRAM,
 	.has_prctl = true,
 	.has_thermal = true,
 };
 
 static const struct aw_sid_conf a83t_conf = {
+	.efuse_size = 0x100,
 	.rootkey_offset = SID_SRAM,
 	.has_prctl = true,
 	.has_thermal = true,
 };
 
+static const struct aw_sid_conf h3_conf = {
+	.efuse_size = 0x100,
+	.rootkey_offset = SID_SRAM,
+	.has_prctl = true,
+	.has_thermal = true,
+	.requires_prctl_read = true,
+};
+
 static struct ofw_compat_data compat_data[] = {
 	{ "allwinner,sun4i-a10-sid",		(uintptr_t)&a10_conf},
 	{ "allwinner,sun7i-a20-sid",		(uintptr_t)&a20_conf},
 	{ "allwinner,sun50i-a64-sid",		(uintptr_t)&a64_conf},
 	{ "allwinner,sun8i-a83t-sid",		(uintptr_t)&a83t_conf},
+	{ "allwinner,sun8i-h3-sid",		(uintptr_t)&h3_conf},
 	{ NULL,					0 }
 };
 
@@ -168,6 +183,8 @@ static int
 aw_sid_attach(device_t dev)
 {
 	struct aw_sid_softc *sc;
+	bus_size_t i;
+	uint32_t val;
 
 	sc = device_get_softc(dev);
 
@@ -180,6 +197,19 @@ aw_sid_attach(device_t dev)
 	sc->sid_conf = (struct aw_sid_conf *)ofw_bus_search_compatible(dev, compat_data)->ocd_data;
 	aw_sid_sc = sc;
 
+	/*
+	 * This set of reads is solely for working around a silicon bug on some
+	 * SoC that require a prctl read in order for direct register access to
+	 * return a non-garbled value. Hence, the values we read are simply
+	 * ignored.
+	 */
+	if (sc->sid_conf->requires_prctl_read)
+		for (i = 0; i < sc->sid_conf->efuse_size; i += 4)
+			if (aw_sid_prctl_read(dev, i, &val) != 0) {
+				device_printf(dev, "failed prctl read\n");
+				return (ENXIO);
+			}
+
 	SYSCTL_ADD_PROC(device_get_sysctl_ctx(dev),
 	    SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
 	    OID_AUTO, "rootkey",