libubb/: helper library for UBB access

libubb/ubb.c

@@ -0,0 +1,93 @@
+/*
+ * libubb/ubb.c - Open/close UBB
+ *
+ * Written 2012 by Werner Almesberger
+ * Copyright 2012 Werner Almesberger
+ *
+ * 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.
+ */
+
+
+#include <stdint.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+
+#include <ubb/ubb.h>
+
+
+volatile void *ubb_mem;
+
+static int ubb_fd;
+static uint32_t data, dir, pull, func, sel;
+
+
+static void *map(off_t addr, size_t size, int *fd)
+{
+	void *mem;
+
+	*fd = open("/dev/mem", O_RDWR | O_SYNC);
+	if (*fd < 0)
+		return NULL;
+	mem = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, *fd, addr);
+	if (mem == MAP_FAILED) {
+		(void) close(*fd);
+		return NULL;
+	}
+	return mem;
+}
+
+
+int ubb_open(uint32_t keep)
+{
+	ubb_mem = map(UBB_SOC_BASE, UBB_REG_WINDOW, &ubb_fd);
+	if (!ubb_mem)
+		return -1;
+
+	data = PDDAT & UBB_ALL;
+	dir = PDDIR & UBB_ALL;
+	pull = PDPULL & UBB_ALL;
+	func = PDFUN & UBB_ALL;
+	sel = PDSEL & UBB_ALL;
+
+	/* enable pull-ups to let card ramp up power */
+
+	PDPULLC = UBB_ALL_IO & ~keep;
+	PDDIRC = UBB_ALL_IO & ~keep;
+
+	PDFUNC = UBB_ALL & ~keep;
+	PDSELC = UBB_ALL & ~keep;
+
+	PDDATS = UBB_nPWR & ~keep;
+	PDDIRS = UBB_nPWR & ~keep;
+
+	return 0;
+}
+
+
+void ubb_power(int on)
+{
+	if (on) {
+		usleep(10*1000);
+		PDDATC = UBB_nPWR;
+	} else {
+		PDDATS = UBB_nPWR;
+	}
+}
+
+
+void ubb_close(uint32_t keep)
+{
+	PDSELS = sel & ~keep;
+	PDFUNS = func & ~keep;
+
+	PDDATS = (data | UBB_nPWR) & ~keep;
+	PDDIRS = (dir | UBB_nPWR) & ~keep;
+
+	PDPULLS = pull & ~keep;
+
+	close(ubb_fd);
+}