MIPS: lantiq: implement support for clkdev api

This patch unifies all clock generation and gating code into one file.
All drivers will now be able to request their clocks via their device.
This patch also adds support for the clockout feature, which allows
clock generation on external pins.

Support for COMMON_CLK will be provided in the next series.

Signed-off-by: John Crispin <blogic@openwrt.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/3804/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 79 insertions, 67 deletions

diff --git a/arch/mips/lantiq/clk.c b/arch/mips/lantiq/clk.c
index 412814fdd3ee..d3bcc33f4699 100644
--- a/arch/mips/lantiq/clk.c
+++ b/arch/mips/lantiq/clk.c
@@ -12,6 +12,7 @@
 #include <linux/kernel.h>
 #include <linux/types.h>
 #include <linux/clk.h>
+#include <linux/clkdev.h>
 #include <linux/err.h>
 #include <linux/list.h>
 
@@ -22,44 +23,32 @@
 #include <lantiq_soc.h>
 
 #include "clk.h"
+#include "prom.h"
 
-struct clk {
-	const char *name;
-	unsigned long rate;
-	unsigned long (*get_rate) (void);
-};
+/* lantiq socs have 3 static clocks */
+static struct clk cpu_clk_generic[3];
 
-static struct clk *cpu_clk;
-static int cpu_clk_cnt;
+void clkdev_add_static(unsigned long cpu, unsigned long fpi, unsigned long io)
+{
+	cpu_clk_generic[0].rate = cpu;
+	cpu_clk_generic[1].rate = fpi;
+	cpu_clk_generic[2].rate = io;
+}
 
-/* lantiq socs have 3 static clocks */
-static struct clk cpu_clk_generic[] = {
-	{
-		.name = "cpu",
-		.get_rate = ltq_get_cpu_hz,
-	}, {
-		.name = "fpi",
-		.get_rate = ltq_get_fpi_hz,
-	}, {
-		.name = "io",
-		.get_rate = ltq_get_io_region_clock,
-	},
-};
-
-static struct resource ltq_cgu_resource = {
-	.name	= "cgu",
-	.start	= LTQ_CGU_BASE_ADDR,
-	.end	= LTQ_CGU_BASE_ADDR + LTQ_CGU_SIZE - 1,
-	.flags	= IORESOURCE_MEM,
-};
-
-/* remapped clock register range */
-void __iomem *ltq_cgu_membase;
-
-void clk_init(void)
+struct clk *clk_get_cpu(void)
+{
+	return &cpu_clk_generic[0];
+}
+
+struct clk *clk_get_fpi(void)
+{
+	return &cpu_clk_generic[1];
+}
+EXPORT_SYMBOL_GPL(clk_get_fpi);
+
+struct clk *clk_get_io(void)
 {
-	cpu_clk = cpu_clk_generic;
-	cpu_clk_cnt = ARRAY_SIZE(cpu_clk_generic);
+	return &cpu_clk_generic[2];
 }
 
 static inline int clk_good(struct clk *clk)
@@ -82,38 +71,71 @@ unsigned long clk_get_rate(struct clk *clk)
 }
 EXPORT_SYMBOL(clk_get_rate);
 
-struct clk *clk_get(struct device *dev, const char *id)
+int clk_set_rate(struct clk *clk, unsigned long rate)
 {
-	int i;
-
-	for (i = 0; i < cpu_clk_cnt; i++)
-		if (!strcmp(id, cpu_clk[i].name))
-			return &cpu_clk[i];
-	BUG();
-	return ERR_PTR(-ENOENT);
-}
-EXPORT_SYMBOL(clk_get);
-
-void clk_put(struct clk *clk)
-{
-	/* not used */
+	if (unlikely(!clk_good(clk)))
+		return 0;
+	if (clk->rates && *clk->rates) {
+		unsigned long *r = clk->rates;
+
+		while (*r && (*r != rate))
+			r++;
+		if (!*r) {
+			pr_err("clk %s.%s: trying to set invalid rate %ld\n",
+				clk->cl.dev_id, clk->cl.con_id, rate);
+			return -1;
+		}
+	}
+	clk->rate = rate;
+	return 0;
 }
-EXPORT_SYMBOL(clk_put);
+EXPORT_SYMBOL(clk_set_rate);
 
 int clk_enable(struct clk *clk)
 {
-	/* not used */
-	return 0;
+	if (unlikely(!clk_good(clk)))
+		return -1;
+
+	if (clk->enable)
+		return clk->enable(clk);
+
+	return -1;
 }
 EXPORT_SYMBOL(clk_enable);
 
 void clk_disable(struct clk *clk)
 {
-	/* not used */
+	if (unlikely(!clk_good(clk)))
+		return;
+
+	if (clk->disable)
+		clk->disable(clk);
 }
 EXPORT_SYMBOL(clk_disable);
 
-static inline u32 ltq_get_counter_resolution(void)
+int clk_activate(struct clk *clk)
+{
+	if (unlikely(!clk_good(clk)))
+		return -1;
+
+	if (clk->activate)
+		return clk->activate(clk);
+
+	return -1;
+}
+EXPORT_SYMBOL(clk_activate);
+
+void clk_deactivate(struct clk *clk)
+{
+	if (unlikely(!clk_good(clk)))
+		return;
+
+	if (clk->deactivate)
+		clk->deactivate(clk);
+}
+EXPORT_SYMBOL(clk_deactivate);
+
+static inline u32 get_counter_resolution(void)
 {
 	u32 res;
 
@@ -133,21 +155,11 @@ void __init plat_time_init(void)
 {
 	struct clk *clk;
 
-	if (insert_resource(&iomem_resource, &ltq_cgu_resource) < 0)
-		panic("Failed to insert cgu memory");
+	ltq_soc_init();
 
-	if (request_mem_region(ltq_cgu_resource.start,
-			resource_size(&ltq_cgu_resource), "cgu") < 0)
-		panic("Failed to request cgu memory");
-
-	ltq_cgu_membase = ioremap_nocache(ltq_cgu_resource.start,
-				resource_size(&ltq_cgu_resource));
-	if (!ltq_cgu_membase) {
-		pr_err("Failed to remap cgu memory\n");
-		unreachable();
-	}
-	clk = clk_get(0, "cpu");
-	mips_hpt_frequency = clk_get_rate(clk) / ltq_get_counter_resolution();
+	clk = clk_get_cpu();
+	mips_hpt_frequency = clk_get_rate(clk) / get_counter_resolution();
 	write_c0_compare(read_c0_count());
+	pr_info("CPU Clock: %ldMHz\n", clk_get_rate(clk) / 1000000);
 	clk_put(clk);
 }