ARM: davinci: psc: introduce reset API

Introduce an IP reset API for use on DaVinci SoC.

There is no existing "reset" framework support for SoC devices.
The remoteproc driver needs explicit control of the DSP's reset line.
To support this, a new DaVinci specific API is added.

This private API will disappear with DT migration.  Some discussion
regarding a proposed DT "reset" binding is here:
https://patchwork.kernel.org/patch/1635051/

Modify davinci_clk_init() to set clk "reset" function for clocks
that indicate PSC_LRST support.  Also fix indentation issue with
function opening curly brace.

Signed-off-by: Robert Tivy <rtivy@ti.com>
[nsekhar@ti.com: rename davinci_psc_config_reset() to davinci_psc_reset()]
Signed-off-by: Sekhar Nori <nsekhar@ti.com>

arch/arm/mach-davinci/clock.c

@@ -52,6 +52,40 @@ static void __clk_disable(struct clk *clk)
 		__clk_disable(clk->parent);
 }
 
+int davinci_clk_reset(struct clk *clk, bool reset)
+{
+	unsigned long flags;
+
+	if (clk == NULL || IS_ERR(clk))
+		return -EINVAL;
+
+	spin_lock_irqsave(&clockfw_lock, flags);
+	if (clk->flags & CLK_PSC)
+		davinci_psc_reset(clk->gpsc, clk->lpsc, reset);
+	spin_unlock_irqrestore(&clockfw_lock, flags);
+
+	return 0;
+}
+EXPORT_SYMBOL(davinci_clk_reset);
+
+int davinci_clk_reset_assert(struct clk *clk)
+{
+	if (clk == NULL || IS_ERR(clk) || !clk->reset)
+		return -EINVAL;
+
+	return clk->reset(clk, true);
+}
+EXPORT_SYMBOL(davinci_clk_reset_assert);
+
+int davinci_clk_reset_deassert(struct clk *clk)
+{
+	if (clk == NULL || IS_ERR(clk) || !clk->reset)
+		return -EINVAL;
+
+	return clk->reset(clk, false);
+}
+EXPORT_SYMBOL(davinci_clk_reset_deassert);
+
 int clk_enable(struct clk *clk)
 {
 	unsigned long flags;
@@ -535,7 +569,7 @@ int davinci_set_refclk_rate(unsigned long rate)
 }
 
 int __init davinci_clk_init(struct clk_lookup *clocks)
-  {
+{
 	struct clk_lookup *c;
 	struct clk *clk;
 	size_t num_clocks = 0;
@@ -576,6 +610,9 @@ int __init davinci_clk_init(struct clk_lookup *clocks)
 		if (clk->lpsc)
 			clk->flags |= CLK_PSC;
 
+		if (clk->flags & PSC_LRST)
+			clk->reset = davinci_clk_reset;
+
 		clk_register(clk);
 		num_clocks++;