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/psc.c

@@ -48,6 +48,31 @@ int __init davinci_psc_is_clk_active(unsigned int ctlr, unsigned int id)
 	return mdstat & BIT(12);
 }
 
+/* Control "reset" line associated with PSC domain */
+void davinci_psc_reset(unsigned int ctlr, unsigned int id, bool reset)
+{
+	u32 mdctl;
+	void __iomem *psc_base;
+	struct davinci_soc_info *soc_info = &davinci_soc_info;
+
+	if (!soc_info->psc_bases || (ctlr >= soc_info->psc_bases_num)) {
+		pr_warn("PSC: Bad psc data: 0x%x[%d]\n",
+				(int)soc_info->psc_bases, ctlr);
+		return;
+	}
+
+	psc_base = ioremap(soc_info->psc_bases[ctlr], SZ_4K);
+
+	mdctl = readl(psc_base + MDCTL + 4 * id);
+	if (reset)
+		mdctl &= ~MDCTL_LRST;
+	else
+		mdctl |= MDCTL_LRST;
+	writel(mdctl, psc_base + MDCTL + 4 * id);
+
+	iounmap(psc_base);
+}
+
 /* Enable or disable a PSC domain */
 void davinci_psc_config(unsigned int domain, unsigned int ctlr,
 		unsigned int id, bool enable, u32 flags)