ARM: 8242/1: sa1100: add cpu clock

Both SA1100 framebuffer and PCMCIA drivers require knowledge of cpu frequency to correctly program timings. Currently they receive timing information by calling cpufreq_get(0). However if cpu frequency driver is not enabled (e.g. due to unsupported DRAM chip/board on sa1110) cpufreq_get(0) returns 0, causing incorrect timings to be programmed. Add cpu clock returning cpu frequency, to be used by sa11x0 fb and pcmcia drivers. Signed-off-by: Dmitry Eremin-Solenikov <[email protected]> Signed-off-by: Russell King <[email protected]>
kazikcz · Dec 5, 2014 · 4faee12 · 4faee12
1 parent ab71f99
commit 4faee12
Showing 1 changed file with 34 additions and 7 deletions.
diff --git a/arch/arm/mach-sa1100/clock.c b/arch/arm/mach-sa1100/clock.c
@@ -15,10 +15,12 @@
 #include <linux/clkdev.h>
 
 #include <mach/hardware.h>
+#include <mach/generic.h>
 
 struct clkops {
 	void			(*enable)(struct clk *);
 	void			(*disable)(struct clk *);
+	unsigned long		(*get_rate)(struct clk *);
 };
 
 struct clk {
@@ -33,13 +35,6 @@ struct clk clk_##_name = {				\
 
 static DEFINE_SPINLOCK(clocks_lock);
 
-/* Dummy clk routine to build generic kernel parts that may be using them */
-unsigned long clk_get_rate(struct clk *clk)
-{
-	return 0;
-}
-EXPORT_SYMBOL(clk_get_rate);
-
 static void clk_gpio27_enable(struct clk *clk)
 {
 	/*
@@ -58,6 +53,19 @@ static void clk_gpio27_disable(struct clk *clk)
 	GAFR &= ~GPIO_32_768kHz;
 }
 
+static void clk_cpu_enable(struct clk *clk)
+{
+}
+
+static void clk_cpu_disable(struct clk *clk)
+{
+}
+
+static unsigned long clk_cpu_get_rate(struct clk *clk)
+{
+	return sa11x0_getspeed(0) * 1000;
+}
+
 int clk_enable(struct clk *clk)
 {
 	unsigned long flags;
@@ -87,16 +95,35 @@ void clk_disable(struct clk *clk)
 }
 EXPORT_SYMBOL(clk_disable);
 
+unsigned long clk_get_rate(struct clk *clk)
+{
+	if (clk && clk->ops && clk->ops->get_rate)
+		return clk->ops->get_rate(clk);
+
+	return 0;
+}
+EXPORT_SYMBOL(clk_get_rate);
+
 const struct clkops clk_gpio27_ops = {
 	.enable		= clk_gpio27_enable,
 	.disable	= clk_gpio27_disable,
 };
 
+const struct clkops clk_cpu_ops = {
+	.enable		= clk_cpu_enable,
+	.disable	= clk_cpu_disable,
+	.get_rate	= clk_cpu_get_rate,
+};
+
 static DEFINE_CLK(gpio27, &clk_gpio27_ops);
 
+static DEFINE_CLK(cpu, &clk_cpu_ops);
+
 static struct clk_lookup sa11xx_clkregs[] = {
 	CLKDEV_INIT("sa1111.0", NULL, &clk_gpio27),
 	CLKDEV_INIT("sa1100-rtc", NULL, NULL),
+	CLKDEV_INIT("sa11x0-fb", NULL, &clk_cpu),
+	CLKDEV_INIT("sa11x0-pcmcia", NULL, &clk_cpu),
 };
 
 static int __init sa11xx_clk_init(void)