1 files changed, 75 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/msdi.c b/arch/arm/mach-omap2/msdi.c
new file mode 100644
index 0000000000..552b2fa4e4
--- /dev/null
+++ b/arch/arm/mach-omap2/msdi.c
@@ -0,0 +1,75 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * MSDI IP block reset
+ *
+ * Copyright (C) 2012 Texas Instruments, Inc.
+ * Paul Walmsley
+ *
+ * XXX What about pad muxing?
+ */
+
+#include <linux/kernel.h>
+#include <linux/err.h>
+
+#include "prm.h"
+#include "common.h"
+#include "control.h"
+#include "omap_hwmod.h"
+#include "omap_device.h"
+#include "mmc.h"
+
+/*
+ * MSDI_CON_OFFSET: offset in bytes of the MSDI IP block's CON register
+ *     from the IP block's base address
+ */
+#define MSDI_CON_OFFSET				0x0c
+
+/* Register bitfields in the CON register */
+#define MSDI_CON_POW_MASK			BIT(11)
+#define MSDI_CON_CLKD_MASK			(0x3f << 0)
+#define MSDI_CON_CLKD_SHIFT			0
+
+/* MSDI_TARGET_RESET_CLKD: clock divisor to use throughout the reset */
+#define MSDI_TARGET_RESET_CLKD		0x3ff
+
+/**
+ * omap_msdi_reset - reset the MSDI IP block
+ * @oh: struct omap_hwmod *
+ *
+ * The MSDI IP block on OMAP2420 has to have both the POW and CLKD
+ * fields set inside its CON register for a reset to complete
+ * successfully.  This is not documented in the TRM.  For CLKD, we use
+ * the value that results in the lowest possible clock rate, to attempt
+ * to avoid disturbing any cards.
+ */
+int omap_msdi_reset(struct omap_hwmod *oh)
+{
+	u16 v = 0;
+	int c = 0;
+
+	/* Write to the SOFTRESET bit */
+	omap_hwmod_softreset(oh);
+
+	/* Enable the MSDI core and internal clock */
+	v |= MSDI_CON_POW_MASK;
+	v |= MSDI_TARGET_RESET_CLKD << MSDI_CON_CLKD_SHIFT;
+	omap_hwmod_write(v, oh, MSDI_CON_OFFSET);
+
+	/* Poll on RESETDONE bit */
+	omap_test_timeout((omap_hwmod_read(oh, oh->class->sysc->syss_offs)
+			   & SYSS_RESETDONE_MASK),
+			  MAX_MODULE_SOFTRESET_WAIT, c);
+
+	if (c == MAX_MODULE_SOFTRESET_WAIT)
+		pr_warn("%s: %s: softreset failed (waited %d usec)\n",
+			__func__, oh->name, MAX_MODULE_SOFTRESET_WAIT);
+	else
+		pr_debug("%s: %s: softreset in %d usec\n", __func__,
+			 oh->name, c);
+
+	/* Disable the MSDI internal clock */
+	v &= ~MSDI_CON_CLKD_MASK;
+	omap_hwmod_write(v, oh, MSDI_CON_OFFSET);
+
+	return 0;
+}