1 files changed, 69 insertions, 0 deletions
diff --git a/kernel/arch/arm/mach-omap2/clock36xx.c b/kernel/arch/arm/mach-omap2/clock36xx.c
new file mode 100644
index 000000000..91ccb962e
--- /dev/null
+++ b/kernel/arch/arm/mach-omap2/clock36xx.c
@@ -0,0 +1,69 @@
+/*
+ * OMAP36xx-specific clkops
+ *
+ * Copyright (C) 2010 Texas Instruments, Inc.
+ * Copyright (C) 2010 Nokia Corporation
+ *
+ * Mike Turquette
+ * Vijaykumar GN
+ * Paul Walmsley
+ *
+ * Parts of this code are based on code written by
+ * Richard Woodruff, Tony Lindgren, Tuukka Tikkanen, Karthik Dasu,
+ * Russell King
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#undef DEBUG
+
+#include <linux/kernel.h>
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/io.h>
+
+#include "clock.h"
+#include "clock36xx.h"
+#define to_clk_divider(_hw) container_of(_hw, struct clk_divider, hw)
+
+/**
+ * omap36xx_pwrdn_clk_enable_with_hsdiv_restore - enable clocks suffering
+ *         from HSDivider PWRDN problem Implements Errata ID: i556.
+ * @clk: DPLL output struct clk
+ *
+ * 3630 only: dpll3_m3_ck, dpll4_m2_ck, dpll4_m3_ck, dpll4_m4_ck,
+ * dpll4_m5_ck & dpll4_m6_ck dividers gets loaded with reset
+ * valueafter their respective PWRDN bits are set.  Any dummy write
+ * (Any other value different from the Read value) to the
+ * corresponding CM_CLKSEL register will refresh the dividers.
+ */
+int omap36xx_pwrdn_clk_enable_with_hsdiv_restore(struct clk_hw *clk)
+{
+	struct clk_divider *parent;
+	struct clk_hw *parent_hw;
+	u32 dummy_v, orig_v;
+	struct clk_hw_omap *omap_clk = to_clk_hw_omap(clk);
+	int ret;
+
+	/* Clear PWRDN bit of HSDIVIDER */
+	ret = omap2_dflt_clk_enable(clk);
+
+	parent_hw = __clk_get_hw(__clk_get_parent(clk->clk));
+	parent = to_clk_divider(parent_hw);
+
+	/* Restore the dividers */
+	if (!ret) {
+		orig_v = omap2_clk_readl(omap_clk, parent->reg);
+		dummy_v = orig_v;
+
+		/* Write any other value different from the Read value */
+		dummy_v ^= (1 << parent->shift);
+		omap2_clk_writel(dummy_v, omap_clk, parent->reg);
+
+		/* Write the original divider */
+		omap2_clk_writel(orig_v, omap_clk, parent->reg);
+	}
+
+	return ret;
+}