CLK: TI: add DT alias clock registration mechanism

Some devices require their clocks to be available with a specific
dev-id con-id mapping. With DT, the clocks can be found by default
only with their name, or alternatively through the device node of
the consumer. With drivers, that don't support DT fully yet, add
mechanism to register specific clock names.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

drivers/clk/Makefile

@@ -38,6 +38,7 @@ obj-$(CONFIG_PLAT_SAMSUNG)	+= samsung/
 obj-$(CONFIG_COMMON_CLK_XGENE)  += clk-xgene.o
 obj-$(CONFIG_COMMON_CLK_KEYSTONE)	+= keystone/
 obj-$(CONFIG_ARCH_SHMOBILE_MULTI)	+= shmobile/
+obj-$(CONFIG_ARCH_OMAP2PLUS)	+= ti/
 
 obj-$(CONFIG_X86)		+= x86/
 

drivers/clk/ti/Makefile

@@ -0,0 +1,3 @@
+ifneq ($(CONFIG_OF),)
+obj-y					+= clk.o
+endif

drivers/clk/ti/clk.c

@@ -0,0 +1,55 @@
+/*
+ * TI clock support
+ *
+ * Copyright (C) 2013 Texas Instruments, Inc.
+ *
+ * Tero Kristo <t-kristo@ti.com>
+ *
+ * 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.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/clkdev.h>
+#include <linux/clk/ti.h>
+#include <linux/of.h>
+
+#undef pr_fmt
+#define pr_fmt(fmt) "%s: " fmt, __func__
+
+/**
+ * ti_dt_clocks_register - register DT alias clocks during boot
+ * @oclks: list of clocks to register
+ *
+ * Register alias or non-standard DT clock entries during boot. By
+ * default, DT clocks are found based on their node name. If any
+ * additional con-id / dev-id -> clock mapping is required, use this
+ * function to list these.
+ */
+void __init ti_dt_clocks_register(struct ti_dt_clk oclks[])
+{
+	struct ti_dt_clk *c;
+	struct device_node *node;
+	struct clk *clk;
+	struct of_phandle_args clkspec;
+
+	for (c = oclks; c->node_name != NULL; c++) {
+		node = of_find_node_by_name(NULL, c->node_name);
+		clkspec.np = node;
+		clk = of_clk_get_from_provider(&clkspec);
+
+		if (!IS_ERR(clk)) {
+			c->lk.clk = clk;
+			clkdev_add(&c->lk);
+		} else {
+			pr_warn("failed to lookup clock node %s\n",
+				c->node_name);
+		}
+	}
+}

include/linux/clk/ti.h

@@ -0,0 +1,42 @@
+/*
+ * TI clock drivers support
+ *
+ * Copyright (C) 2013 Texas Instruments, Inc.
+ *
+ * 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.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+#ifndef __LINUX_CLK_TI_H__
+#define __LINUX_CLK_TI_H__
+
+#include <linux/clkdev.h>
+
+/**
+ * struct ti_dt_clk - OMAP DT clock alias declarations
+ * @lk: clock lookup definition
+ * @node_name: clock DT node to map to
+ */
+struct ti_dt_clk {
+	struct clk_lookup		lk;
+	char				*node_name;
+};
+
+#define DT_CLK(dev, con, name)		\
+	{				\
+		.lk = {			\
+			.dev_id = dev,	\
+			.con_id = con,	\
+		},			\
+		.node_name = name,	\
+	}
+
+
+void ti_dt_clocks_register(struct ti_dt_clk *oclks);
+
+#endif