From 31318f0793044de2c9bb912e38abbd55c3b584a6 Mon Sep 17 00:00:00 2001
From: Adrian Chadd <adrian@FreeBSD.org>
Date: Thu, 23 Jun 2016 01:14:33 +0000
Subject: [PATCH] [BHND/bcma] Add implementation of BHND_BUS_RESET_CORE
 function for BCMA

This patch addes missing implementation of BHND_BUS_RESET_CORE function for BCMA.
The reset procedure is very simple: enable reset mode, stop clocking,
enable clocking & force clock gating, disable reset mode, stop clock gating.

Tested:

* (michael) Tested on ASUS RT-N53 for enabling/reset USB core

Submitted by:	Michael Zhilin <mizhka@gmail.com>
Approved by:	re (gjb)
---
 sys/dev/bhnd/bcma/bcma.c   | 29 +++++++++++++++++++++++++++--
 sys/dev/bhnd/bhnd_core.h   | 10 +++++++++-
 sys/dev/bhnd/bhndb/bhndb.c |  6 ++++--
 3 files changed, 40 insertions(+), 5 deletions(-)

diff --git a/sys/dev/bhnd/bcma/bcma.c b/sys/dev/bhnd/bcma/bcma.c
index b9bfbad5e411..932c64b36510 100644
--- a/sys/dev/bhnd/bcma/bcma.c
+++ b/sys/dev/bhnd/bcma/bcma.c
@@ -43,6 +43,7 @@ __FBSDID("$FreeBSD$");
 
 #include "bcma_eromreg.h"
 #include "bcma_eromvar.h"
+#include <dev/bhnd/bhnd_core.h>
 
 int
 bcma_probe(device_t dev)
@@ -218,9 +219,33 @@ bcma_reset_core(device_t dev, device_t child, uint16_t flags)
 	if (dinfo->res_agent == NULL)
 		return (ENODEV);
 
-	// TODO - perform reset
+	/* Start reset */
+	bhnd_bus_write_4(dinfo->res_agent, BHND_RESET_CF, BHND_RESET_CF_ENABLE);
+	bhnd_bus_read_4(dinfo->res_agent, BHND_RESET_CF);
+	DELAY(10);
 
-	return (ENXIO);
+	/* Disable clock */
+	bhnd_bus_write_4(dinfo->res_agent, BHND_CF, flags);
+	bhnd_bus_read_4(dinfo->res_agent, BHND_CF);
+	DELAY(10);
+
+	/* Enable clocks & force clock gating */
+	bhnd_bus_write_4(dinfo->res_agent, BHND_CF, BHND_CF_CLOCK_EN |
+	    BHND_CF_FGC | flags);
+	bhnd_bus_read_4(dinfo->res_agent, BHND_CF);
+	DELAY(10);
+
+	/* Complete reset */
+	bhnd_bus_write_4(dinfo->res_agent, BHND_RESET_CF, 0);
+	bhnd_bus_read_4(dinfo->res_agent, BHND_RESET_CF);
+	DELAY(10);
+
+	/* Release force clock gating */
+	bhnd_bus_write_4(dinfo->res_agent, BHND_CF, BHND_CF_CLOCK_EN | flags);
+	bhnd_bus_read_4(dinfo->res_agent, BHND_CF);
+	DELAY(10);
+
+	return (0);
 }
 
 static int
diff --git a/sys/dev/bhnd/bhnd_core.h b/sys/dev/bhnd/bhnd_core.h
index 9ea955ad1c97..f635a642b5d6 100644
--- a/sys/dev/bhnd/bhnd_core.h
+++ b/sys/dev/bhnd/bhnd_core.h
@@ -25,19 +25,27 @@
 #define _BHND_BHND_CORE_H_
 
 /* Common core control flags */
-#define	BHND_CF_BIST_EN		0x8000		/**< ??? */
+#define	BHND_CF 		0x0408
+#define	BHND_CF_BIST_EN		0x8000		/**< built-in self test */
 #define	BHND_CF_PME_EN		0x4000		/**< ??? */
 #define	BHND_CF_CORE_BITS	0x3ffc		/**< core specific flag mask */
 #define	BHND_CF_FGC		0x0002		/**< force clock gating */
 #define	BHND_CF_CLOCK_EN	0x0001		/**< enable clock */
 
 /* Common core status flags */
+#define	BHND_SF			0x0500
 #define	BHND_SF_BIST_DONE	0x8000		/**< ??? */
 #define	BHND_SF_BIST_ERROR	0x4000		/**< ??? */
 #define	BHND_SF_GATED_CLK	0x2000		/**< clock gated */
 #define	BHND_SF_DMA64		0x1000		/**< supports 64-bit DMA */
 #define	BHND_SF_CORE_BITS	0x0fff		/**< core-specific status mask */
 
+/*Reset core control flags */
+#define	BHND_RESET_CF		0x0800
+#define	BHND_RESET_CF_ENABLE	0x0001
+
+#define	BHND_RESET_SF		0x0804
+
 /* 
  * A register that is common to all cores to
  * communicate w/PMU regarding clock control.
diff --git a/sys/dev/bhnd/bhndb/bhndb.c b/sys/dev/bhnd/bhndb/bhndb.c
index 7668dca57988..f969943ddf3b 100644
--- a/sys/dev/bhnd/bhndb/bhndb.c
+++ b/sys/dev/bhnd/bhndb/bhndb.c
@@ -62,7 +62,7 @@ __FBSDID("$FreeBSD$");
 #include "bhndb_private.h"
 
 /* Debugging flags */
-static u_long bhndb_debug = 0;
+static u_long bhndb_debug = -1;
 TUNABLE_ULONG("hw.bhndb.debug", &bhndb_debug);
 
 enum {
@@ -596,8 +596,10 @@ bhndb_generic_init_full_config(device_t dev, device_t child,
 	hostb = NULL;
 
 	/* Fetch the full set of bhnd-attached cores */
-	if ((error = device_get_children(sc->bus_dev, &devs, &ndevs)))
+	if ((error = device_get_children(sc->bus_dev, &devs, &ndevs))) {
+		device_printf(sc->dev, "unable to get children\n");
 		return (error);
+	}
 
 	/* Find our host bridge device */
 	hostb = BHNDB_FIND_HOSTB_DEVICE(dev, child);