[POWERPC] clk.h interface for platforms

This provides an implementation of the <linux/clk.h> interface for
arch/powerpc using a set of function pointers in clk_functions.
Platforms that want to support this interface should fill
clk_functions and select CONFIG_PPC_CLOCK in Kconfig.

Signed-off-by: Domen Puncer <domen.puncer@telargo.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

5 files changed, 108 insertions, 0 deletions

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 66a329534b5e..26126d27d756 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -663,3 +663,7 @@ config KEYS_COMPAT
         default y
 
 source "crypto/Kconfig"
+
+config PPC_CLOCK
+        bool
+        default n
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 967afc517d8f..b37165effb65 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -24,6 +24,7 @@ obj-$(CONFIG_PPC64)		+= vdso64/
 obj-$(CONFIG_ALTIVEC)           += vecemu.o vector.o
 obj-$(CONFIG_PPC_970_NAP)       += idle_power4.o
 obj-$(CONFIG_PPC_OF)            += of_device.o of_platform.o prom_parse.o
+obj-$(CONFIG_PPC_CLOCK)         += clock.o
 procfs-$(CONFIG_PPC64)          := proc_ppc64.o
 obj-$(CONFIG_PROC_FS)           += $(procfs-y)
 rtaspci-$(CONFIG_PPC64)-$(CONFIG_PCI)   := rtas_pci.o
diff --git a/arch/powerpc/kernel/clock.c b/arch/powerpc/kernel/clock.c
new file mode 100644
index 000000000000..ce668f545758
--- /dev/null
+++ b/arch/powerpc/kernel/clock.c
@@ -0,0 +1,82 @@
+/*
+ * Dummy clk implementations for powerpc.
+ * These need to be overridden in platform code.
+ */
+
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <asm/clk_interface.h>
+
+struct clk_interface clk_functions;
+
+struct clk *clk_get(struct device *dev, const char *id)
+{
+        if (clk_functions.clk_get)
+                return clk_functions.clk_get(dev, id);
+        return ERR_PTR(-ENOSYS);
+}
+EXPORT_SYMBOL(clk_get);
+
+void clk_put(struct clk *clk)
+{
+        if (clk_functions.clk_put)
+                clk_functions.clk_put(clk);
+}
+EXPORT_SYMBOL(clk_put);
+
+int clk_enable(struct clk *clk)
+{
+        if (clk_functions.clk_enable)
+                return clk_functions.clk_enable(clk);
+        return -ENOSYS;
+}
+EXPORT_SYMBOL(clk_enable);
+
+void clk_disable(struct clk *clk)
+{
+        if (clk_functions.clk_disable)
+                clk_functions.clk_disable(clk);
+}
+EXPORT_SYMBOL(clk_disable);
+
+unsigned long clk_get_rate(struct clk *clk)
+{
+        if (clk_functions.clk_get_rate)
+                return clk_functions.clk_get_rate(clk);
+        return 0;
+}
+EXPORT_SYMBOL(clk_get_rate);
+
+long clk_round_rate(struct clk *clk, unsigned long rate)
+{
+        if (clk_functions.clk_round_rate)
+                return clk_functions.clk_round_rate(clk, rate);
+        return -ENOSYS;
+}
+EXPORT_SYMBOL(clk_round_rate);
+
+int clk_set_rate(struct clk *clk, unsigned long rate)
+{
+        if (clk_functions.clk_set_rate)
+                return clk_functions.clk_set_rate(clk, rate);
+        return -ENOSYS;
+}
+EXPORT_SYMBOL(clk_set_rate);
+
+struct clk *clk_get_parent(struct clk *clk)
+{
+        if (clk_functions.clk_get_parent)
+                return clk_functions.clk_get_parent(clk);
+        return ERR_PTR(-ENOSYS);
+}
+EXPORT_SYMBOL(clk_get_parent);
+
+int clk_set_parent(struct clk *clk, struct clk *parent)
+{
+        if (clk_functions.clk_set_parent)
+                return clk_functions.clk_set_parent(clk, parent);
+        return -ENOSYS;
+}
+EXPORT_SYMBOL(clk_set_parent);
diff --git a/arch/powerpc/platforms/52xx/Kconfig b/arch/powerpc/platforms/52xx/Kconfig
index 9ddf251b192b..2938d4927b83 100644
--- a/arch/powerpc/platforms/52xx/Kconfig
+++ b/arch/powerpc/platforms/52xx/Kconfig
@@ -1,6 +1,7 @@
 config PPC_MPC52xx
         bool
         select FSL_SOC
+        select PPC_CLOCK
         default n
 
 config PPC_MPC5200
diff --git a/include/asm-powerpc/clk_interface.h b/include/asm-powerpc/clk_interface.h
new file mode 100644
index 000000000000..ab1882c1e176
--- /dev/null
+++ b/include/asm-powerpc/clk_interface.h
@@ -0,0 +1,20 @@
+#ifndef __ASM_POWERPC_CLK_INTERFACE_H
+#define __ASM_POWERPC_CLK_INTERFACE_H
+
+#include <linux/clk.h>
+
+struct clk_interface {
+        struct clk*     (*clk_get)      (struct device *dev, const char *id);
+        int             (*clk_enable)   (struct clk *clk);
+        void            (*clk_disable)  (struct clk *clk);
+        unsigned long   (*clk_get_rate) (struct clk *clk);
+        void            (*clk_put)      (struct clk *clk);
+        long            (*clk_round_rate) (struct clk *clk, unsigned long rate);
+        int             (*clk_set_rate) (struct clk *clk, unsigned long rate);
+        int             (*clk_set_parent) (struct clk *clk, struct clk *parent);
+        struct clk*     (*clk_get_parent) (struct clk *clk);
+};
+
+extern struct clk_interface clk_functions;
+
+#endif /* __ASM_POWERPC_CLK_INTERFACE_H */