p2020ds: add alternate boot bank support using the ngPIXIS FPGA

The Freescale P2020DS board uses a new type of PIXIS FPGA, called the ngPIXIS.
The ngPIXIS has one distinct new feature: the values of the on-board switches
can be selectively overridden with shadow registers.  This feature is used to
boot from a different NOR flash bank, instead of having a register dedicated
for this purpose.  Because the ngPIXIS is so different from the previous PIXIS,
a new file is introduced: ngpixis.c.

Also update the P2020DS checkboard() function to use the new macros defined
in the header file.

Signed-off-by: Timur Tabi <timur@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

1 files changed, 136 insertions, 0 deletions

diff --git a/board/freescale/common/ngpixis.c b/board/freescale/common/ngpixis.c
new file mode 100644
index 0000000..bb6794e
--- /dev/null
+++ b/board/freescale/common/ngpixis.c
@@ -0,0 +1,136 @@
+/**
+ * Copyright 2010 Freescale Semiconductor
+ * Author: Timur Tabi <timur@freescale.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This file provides support for the ngPIXIS, a board-specific FPGA used on
+ * some Freescale reference boards.
+ *
+ * A "switch" is black rectangular block on the motherboard.  It contains
+ * eight "bits".  The ngPIXIS has a set of memory-mapped registers (SWx) that
+ * shadow the actual physical switches.  There is also another set of
+ * registers (ENx) that tell the ngPIXIS which bits of SWx should actually be
+ * used to override the values of the bits in the physical switches.
+ *
+ * The following macros need to be defined:
+ *
+ * PIXIS_BASE - The virtual address of the base of the PIXIS register map
+ *
+ * PIXIS_LBMAP_SWITCH - The switch number (i.e. the "x" in "SWx"). This value
+ *    is used in the PIXIS_SW() macro to determine which offset in
+ *    the PIXIS register map corresponds to the physical switch that controls
+ *    the boot bank.
+ *
+ * PIXIS_LBMAP_MASK - A bit mask the defines which bits in SWx to use.
+ *
+ * PIXIS_LBMAP_SHIFT - The shift value that corresponds to PIXIS_LBMAP_MASK.
+ *
+ * PIXIS_LBMAP_ALTBANK - The value to program into SWx to tell the ngPIXIS to
+ *    boot from the alternate bank.
+ */
+
+#include <common.h>
+#include <command.h>
+#include <watchdog.h>
+#include <asm/cache.h>
+#include <asm/io.h>
+
+#include "ngpixis.h"
+
+/*
+ * Reset the board. This ignores the ENx registers.
+ */
+void pixis_reset(void)
+{
+	out_8(&pixis->rst, 0);
+
+	while (1);
+}
+
+/*
+ * Reset the board.  Like pixis_reset(), but it honors the ENx registers.
+ */
+void pixis_bank_reset(void)
+{
+	out_8(&pixis->vctl, 0);
+	out_8(&pixis->vctl, 1);
+
+	while (1);
+}
+
+/**
+ * Set the boot bank to the power-on default bank
+ */
+void clear_altbank(void)
+{
+	/* Tell the ngPIXIS to use this the bits in the physical switch for the
+	 * boot bank value, instead of the SWx register.  We need to be careful
+	 * only to set the bits in SWx that correspond to the boot bank.
+	 */
+	clrbits_8(&PIXIS_EN(PIXIS_LBMAP_SWITCH), PIXIS_LBMAP_MASK);
+}
+
+/**
+ * Set the boot bank to the alternate bank
+ */
+void set_altbank(void)
+{
+	/* Program the alternate bank number into the SWx register.
+	 */
+	clrsetbits_8(&PIXIS_SW(PIXIS_LBMAP_SWITCH), PIXIS_LBMAP_MASK,
+		     PIXIS_LBMAP_ALTBANK);
+
+	/* Tell the ngPIXIS to use this the bits in the SWx register for the
+	 * boot bank value, instead of the physical switch.  We need to be
+	 * careful only to set the bits in SWx that correspond to the boot bank.
+	 */
+	setbits_8(&PIXIS_EN(PIXIS_LBMAP_SWITCH), PIXIS_LBMAP_MASK);
+}
+
+
+int pixis_reset_cmd(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+{
+	unsigned int i;
+	char *p_altbank = NULL;
+	char *unknown_param = NULL;
+
+	/* No args is a simple reset request.
+	 */
+	if (argc <= 1)
+		pixis_reset();
+
+	for (i = 1; i < argc; i++) {
+		if (strcmp(argv[i], "altbank") == 0) {
+			p_altbank = argv[i];
+			continue;
+		}
+
+		unknown_param = argv[i];
+	}
+
+	if (unknown_param) {
+		printf("Invalid option: %s\n", unknown_param);
+		return 1;
+	}
+
+	if (p_altbank)
+		set_altbank();
+	else
+		clear_altbank();
+
+	pixis_bank_reset();
+
+	/* Shouldn't be reached. */
+	return 0;
+}
+
+U_BOOT_CMD(
+	pixis_reset, CONFIG_SYS_MAXARGS, 1, pixis_reset_cmd,
+	"Reset the board using the FPGA sequencer",
+	"- hard reset to default bank\n"
+	"pixis_reset altbank - reset to alternate bank\n"
+	);