mpc83xx: Add sysreset driver

Add a sysreset driver for the MPC83xx platform.

Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Mario Six <mario.six@gdsys.cc>

1 files changed, 212 insertions, 0 deletions

diff --git a/drivers/sysreset/sysreset_mpc83xx.c b/drivers/sysreset/sysreset_mpc83xx.c
new file mode 100644
index 0000000..9092764
--- /dev/null
+++ b/drivers/sysreset/sysreset_mpc83xx.c
@@ -0,0 +1,212 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2018
+ * Mario Six, Guntermann & Drunck GmbH, mario.six@gdsys.cc
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <sysreset.h>
+#include <wait_bit.h>
+
+#include "sysreset_mpc83xx.h"
+
+/* Magic 4-byte word to enable reset ('RSTE' in ASCII) */
+static const u32 RPR_MAGIC = 0x52535445;
+/* Wait at most 2000ms for reset control enable bit */
+static const uint RESET_WAIT_TIMEOUT = 2000;
+
+/**
+ * __do_reset() - Execute the system reset
+ *
+ * Return: The functions resets the system, and never returns.
+ */
+static int __do_reset(void)
+{
+	ulong msr;
+	int res;
+
+	immap_t *immap = (immap_t *)CONFIG_SYS_IMMR;
+
+	puts("Resetting the board.\n");
+
+	/* Interrupts and MMU off */
+	msr = mfmsr();
+	msr &= ~(MSR_EE | MSR_IR | MSR_DR);
+	mtmsr(msr);
+
+	/* Enable Reset Control Reg */
+	out_be32(&immap->reset.rpr, RPR_MAGIC);
+	sync();
+	isync();
+
+	/* Confirm Reset Control Reg is enabled */
+	res = wait_for_bit_be32(&immap->reset.rcer, RCER_CRE, true,
+				RESET_WAIT_TIMEOUT, false);
+	if (res) {
+		debug("%s: Timed out waiting for reset control to be set\n",
+		      __func__);
+		return res;
+	}
+
+	udelay(200);
+
+	/* Perform reset, only one bit */
+	out_be32(&immap->reset.rcr, RCR_SWHR);
+
+	/* Never executes */
+	return 0;
+}
+
+static int mpc83xx_sysreset_request(struct udevice *dev, enum sysreset_t type)
+{
+	switch (type) {
+	case SYSRESET_WARM:
+	case SYSRESET_COLD:
+		return __do_reset();
+	default:
+		return -EPROTONOSUPPORT;
+	}
+
+	return -EINPROGRESS;
+}
+
+/**
+ * print_83xx_arb_event() - Print arbiter events to buffer
+ * @force: Print arbiter events, even if none are indicated by the system
+ * @buf:   The buffer to receive the printed arbiter event information
+ * @size:  The size of the buffer to receive the printed arbiter event
+ *	   information in bytes
+ *
+ * Return: Number of bytes printed to buffer, -ve on error
+ */
+static int print_83xx_arb_event(bool force, char *buf, int size)
+{
+	int etype = (gd->arch.arbiter_event_attributes & AEATR_EVENT)
+		    >> AEATR_EVENT_SHIFT;
+	int mstr_id = (gd->arch.arbiter_event_attributes & AEATR_MSTR_ID)
+		      >> AEATR_MSTR_ID_SHIFT;
+	int tbst = (gd->arch.arbiter_event_attributes & AEATR_TBST)
+		   >> AEATR_TBST_SHIFT;
+	int tsize = (gd->arch.arbiter_event_attributes & AEATR_TSIZE)
+		    >> AEATR_TSIZE_SHIFT;
+	int ttype = (gd->arch.arbiter_event_attributes & AEATR_TTYPE)
+		    >> AEATR_TTYPE_SHIFT;
+	int tsize_val = (tbst << 3) | tsize;
+	int tsize_bytes = tbst ? (tsize ? tsize : 8) : 16 + 8 * tsize;
+	int res = 0;
+
+	/*
+	 * If we don't force output, and there is no event (event address ==
+	 * 0), then don't print anything
+	 */
+	if (!force && !gd->arch.arbiter_event_address)
+		return 0;
+
+	if (CONFIG_IS_ENABLED(CONFIG_DISPLAY_AER_FULL)) {
+		res = snprintf(buf, size,
+			       "Arbiter Event Status:\n"
+			       "    %s: 0x%08lX\n"
+			       "    %s:    0x%1x  = %s\n"
+			       "    %s:     0x%02x = %s\n"
+			       "    %s: 0x%1x  = %d bytes\n"
+			       "    %s: 0x%02x = %s\n",
+			       "Event Address", gd->arch.arbiter_event_address,
+			       "Event Type", etype, event[etype],
+			       "Master ID", mstr_id, master[mstr_id],
+			       "Transfer Size", tsize_val, tsize_bytes,
+			       "Transfer Type", ttype, transfer[ttype]);
+	} else if (CONFIG_IS_ENABLED(CONFIG_DISPLAY_AER_BRIEF)) {
+		res = snprintf(buf, size,
+			       "Arbiter Event Status: AEATR=0x%08lX, AEADR=0x%08lX\n",
+			       gd->arch.arbiter_event_attributes,
+			       gd->arch.arbiter_event_address);
+	}
+
+	return res;
+}
+
+static int mpc83xx_sysreset_get_status(struct udevice *dev, char *buf, int size)
+{
+	/* Ad-hoc data structure to map RSR bit values to their descriptions */
+	static const struct {
+		/* Bit mask for the bit in question */
+		ulong mask;
+		/* Description of the bitmask in question */
+		char *desc;
+	} bits[] = {
+		{
+		RSR_SWSR, "Software Soft"}, {
+		RSR_SWHR, "Software Hard"}, {
+		RSR_JSRS, "JTAG Soft"}, {
+		RSR_CSHR, "Check Stop"}, {
+		RSR_SWRS, "Software Watchdog"}, {
+		RSR_BMRS, "Bus Monitor"}, {
+		RSR_SRS,  "External/Internal Soft"}, {
+		RSR_HRS,  "External/Internal Hard"}
+	};
+	int res;
+	ulong rsr = gd->arch.reset_status;
+	int i;
+	char *sep;
+
+	res = snprintf(buf, size, "Reset Status:");
+	if (res < 0) {
+		debug("%s: Could not write reset status message (err = %d)\n",
+		      dev->name, res);
+		return -EIO;
+	}
+
+	buf += res;
+	size -= res;
+
+	sep = " ";
+	for (i = 0; i < ARRAY_SIZE(bits); i++)
+		/* Print description of set bits */
+		if (rsr & bits[i].mask) {
+			res = snprintf(buf, size, "%s%s%s", sep, bits[i].desc,
+				       (i == ARRAY_SIZE(bits) - 1) ? "\n" : "");
+			if (res < 0) {
+				debug("%s: Could not write reset status message (err = %d)\n",
+				      dev->name, res);
+				return -EIO;
+			}
+			buf += res;
+			size -= res;
+			sep = ", ";
+		}
+
+	/*
+	 * TODO(mario.six@gdsys.cc): Move this into a dedicated
+	 *			     arbiter driver
+	 */
+	if (CONFIG_IS_ENABLED(CONFIG_DISPLAY_AER_FULL) ||
+	    CONFIG_IS_ENABLED(CONFIG_DISPLAY_AER_BRIEF)) {
+		/*
+		 * If there was a bus monitor reset event, we force the arbiter
+		 * event to be printed
+		 */
+		res = print_83xx_arb_event(rsr & RSR_BMRS, buf, size);
+		if (res < 0) {
+			debug("%s: Could not write arbiter event message (err = %d)\n",
+			      dev->name, res);
+			return -EIO;
+		}
+		buf += res;
+		size -= res;
+	}
+	snprintf(buf, size, "\n");
+
+	return 0;
+}
+
+static struct sysreset_ops mpc83xx_sysreset = {
+	.request	= mpc83xx_sysreset_request,
+	.get_status	= mpc83xx_sysreset_get_status,
+};
+
+U_BOOT_DRIVER(sysreset_mpc83xx) = {
+	.name	= "mpc83xx_sysreset",
+	.id	= UCLASS_SYSRESET,
+	.ops	= &mpc83xx_sysreset,
+};