MIPS: ath79: Use the common clk API

Make the code simpler and open the way for device tree clocks.

[ralf@linux-mips.org: Resolved conflict with 2a552da6 (MIPS/IRQCHIP: Move
irq_chip from arch/mips to drivers/irqchip.)]
Signed-off-by: Alban Bedel <albeu@free.fr>
Cc: linux-mips@linux-mips.org
Cc: Andrew Bresticker <abrestic@chromium.org>
Cc: Qais Yousef <qais.yousef@imgtec.com>
Cc: Wolfram Sang <wsa@the-dreams.de>
Cc: Sergey Ryazanov <ryazanov.s.a@gmail.com>
Cc: Gabor Juhos <juhosg@openwrt.org>
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/9774/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/Kconfig

@@ -124,6 +124,7 @@ config ATH79
 	select CSRC_R4K
 	select DMA_NONCOHERENT
 	select HAVE_CLK
+	select COMMON_CLK
 	select CLKDEV_LOOKUP
 	select IRQ_MIPS_CPU
 	select MIPS_MACHINE

arch/mips/ath79/clock.c

@@ -17,6 +17,7 @@
 #include <linux/err.h>
 #include <linux/clk.h>
 #include <linux/clkdev.h>
+#include <linux/clk-provider.h>
 
 #include <asm/div64.h>
 
@@ -28,21 +29,15 @@
 #define AR724X_BASE_FREQ	5000000
 #define AR913X_BASE_FREQ	5000000
 
-struct clk {
-	unsigned long rate;
-};
-
 static void __init ath79_add_sys_clkdev(const char *id, unsigned long rate)
 {
 	struct clk *clk;
 	int err;
 
-	clk = kzalloc(sizeof(*clk), GFP_KERNEL);
+	clk = clk_register_fixed_rate(NULL, id, NULL, CLK_IS_ROOT, rate);
 	if (!clk)
 		panic("failed to allocate %s clock structure", id);
 
-	clk->rate = rate;
-
 	err = clk_register_clkdev(clk, id, NULL);
 	if (err)
 		panic("unable to register %s clock device", id);
@@ -468,23 +463,3 @@ ath79_get_sys_clk_rate(const char *id)
 
 	return rate;
 }
-
-/*
- * Linux clock API
- */
-int clk_enable(struct clk *clk)
-{
-	return 0;
-}
-EXPORT_SYMBOL(clk_enable);
-
-void clk_disable(struct clk *clk)
-{
-}
-EXPORT_SYMBOL(clk_disable);
-
-unsigned long clk_get_rate(struct clk *clk)
-{
-	return clk->rate;
-}
-EXPORT_SYMBOL(clk_get_rate);