[ARM] versatile: convert to clkdev and lookup clocks by device name

People often point to the Integrator/Versatile/Realview
implementations to justify using the consumer name as the sole
selector for clocks.

Eliminate this excuse by changing the Versatile implementation, so
it provides a better example of how it should be done.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

4 files changed, 61 insertions, 89 deletions

diff --git a/arch/arm/mach-versatile/clock.c b/arch/arm/mach-versatile/clock.c
index 58937f1fb38..c50a44ea7ee 100644
--- a/arch/arm/mach-versatile/clock.c
+++ b/arch/arm/mach-versatile/clock.c
@@ -10,6 +10,7 @@
  */
 #include <linux/module.h>
 #include <linux/kernel.h>
+#include <linux/device.h>
 #include <linux/list.h>
 #include <linux/errno.h>
 #include <linux/err.h>
@@ -17,36 +18,11 @@
 #include <linux/clk.h>
 #include <linux/mutex.h>
 
+#include <asm/clkdev.h>
 #include <asm/hardware/icst307.h>
 
 #include "clock.h"
 
-static LIST_HEAD(clocks);
-static DEFINE_MUTEX(clocks_mutex);
-
-struct clk *clk_get(struct device *dev, const char *id)
-{
-        struct clk *p, *clk = ERR_PTR(-ENOENT);
-
-        mutex_lock(&clocks_mutex);
-        list_for_each_entry(p, &clocks, node) {
-                if (strcmp(id, p->name) == 0 && try_module_get(p->owner)) {
-                        clk = p;
-                        break;
-                }
-        }
-        mutex_unlock(&clocks_mutex);
-
-        return clk;
-}
-EXPORT_SYMBOL(clk_get);
-
-void clk_put(struct clk *clk)
-{
-        module_put(clk->owner);
-}
-EXPORT_SYMBOL(clk_put);
-
 int clk_enable(struct clk *clk)
 {
         return 0;
@@ -66,7 +42,9 @@ EXPORT_SYMBOL(clk_get_rate);
 
 long clk_round_rate(struct clk *clk, unsigned long rate)
 {
-        return rate;
+        struct icst307_vco vco;
+        vco = icst307_khz_to_vco(clk->params, rate / 1000);
+        return icst307_khz(clk->params, vco) * 1000;
 }
 EXPORT_SYMBOL(clk_round_rate);
 
@@ -79,57 +57,9 @@ int clk_set_rate(struct clk *clk, unsigned long rate)
 
                 vco = icst307_khz_to_vco(clk->params, rate / 1000);
                 clk->rate = icst307_khz(clk->params, vco) * 1000;
-
-                printk("Clock %s: setting VCO reg params: S=%d R=%d V=%d\n",
-                        clk->name, vco.s, vco.r, vco.v);
-
                 clk->setvco(clk, vco);
                 ret = 0;
         }
         return ret;
 }
 EXPORT_SYMBOL(clk_set_rate);
-
-/*
- * These are fixed clocks.
- */
-static struct clk kmi_clk = {
-        .name   = "KMIREFCLK",
-        .rate   = 24000000,
-};
-
-static struct clk uart_clk = {
-        .name   = "UARTCLK",
-        .rate   = 24000000,
-};
-
-static struct clk mmci_clk = {
-        .name   = "MCLK",
-        .rate   = 24000000,
-};
-
-int clk_register(struct clk *clk)
-{
-        mutex_lock(&clocks_mutex);
-        list_add(&clk->node, &clocks);
-        mutex_unlock(&clocks_mutex);
-        return 0;
-}
-EXPORT_SYMBOL(clk_register);
-
-void clk_unregister(struct clk *clk)
-{
-        mutex_lock(&clocks_mutex);
-        list_del(&clk->node);
-        mutex_unlock(&clocks_mutex);
-}
-EXPORT_SYMBOL(clk_unregister);
-
-static int __init clk_init(void)
-{
-        clk_register(&kmi_clk);
-        clk_register(&uart_clk);
-        clk_register(&mmci_clk);
-        return 0;
-}
-arch_initcall(clk_init);
diff --git a/arch/arm/mach-versatile/clock.h b/arch/arm/mach-versatile/clock.h
index 8b0b61dd17e..03468fdc3e5 100644
--- a/arch/arm/mach-versatile/clock.h
+++ b/arch/arm/mach-versatile/clock.h
@@ -12,14 +12,9 @@ struct module;
 struct icst307_params;
 
 struct clk {
-        struct list_head        node;
         unsigned long           rate;
-        struct module           *owner;
-        const char              *name;
         const struct icst307_params *params;
+        u32                     oscoff;
         void                    *data;
         void                    (*setvco)(struct clk *, struct icst307_vco vco);
 };
-
-int clk_register(struct clk *clk);
-void clk_unregister(struct clk *clk);
diff --git a/arch/arm/mach-versatile/core.c b/arch/arm/mach-versatile/core.c
index 565e0ba0d67..df25aa13850 100644
--- a/arch/arm/mach-versatile/core.c
+++ b/arch/arm/mach-versatile/core.c
@@ -31,6 +31,7 @@
 #include <linux/cnt32_to_63.h>
 #include <linux/io.h>
 
+#include <asm/clkdev.h>
 #include <asm/system.h>
 #include <mach/hardware.h>
 #include <asm/irq.h>
@@ -373,22 +374,60 @@ static const struct icst307_params versatile_oscvco_params = {
 
 static void versatile_oscvco_set(struct clk *clk, struct icst307_vco vco)
 {
-        void __iomem *sys_lock = __io_address(VERSATILE_SYS_BASE) + VERSATILE_SYS_LOCK_OFFSET;
-        void __iomem *sys_osc = __io_address(VERSATILE_SYS_BASE) + VERSATILE_SYS_OSCCLCD_OFFSET;
+        void __iomem *sys = __io_address(VERSATILE_SYS_BASE);
+        void __iomem *sys_lock = sys + VERSATILE_SYS_LOCK_OFFSET;
         u32 val;
 
-        val = readl(sys_osc) & ~0x7ffff;
+        val = readl(sys + clk->oscoff) & ~0x7ffff;
         val |= vco.v | (vco.r << 9) | (vco.s << 16);
 
         writel(0xa05f, sys_lock);
-        writel(val, sys_osc);
+        writel(val, sys + clk->oscoff);
         writel(0, sys_lock);
 }
 
-static struct clk versatile_clcd_clk = {
-        .name   = "CLCDCLK",
+static struct clk osc4_clk = {
         .params = &versatile_oscvco_params,
-        .setvco = versatile_oscvco_set,
+        .oscoff = VERSATILE_SYS_OSCCLCD_OFFSET,
+        .setvco = versatile_oscvco_set,
+};
+
+/*
+ * These are fixed clocks.
+ */
+static struct clk ref24_clk = {
+        .rate   = 24000000,
+};
+
+static struct clk_lookup lookups[] __initdata = {
+        {       /* UART0 */
+                .dev_id         = "dev:f1",
+                .clk            = &ref24_clk,
+        }, {    /* UART1 */
+                .dev_id         = "dev:f2",
+                .clk            = &ref24_clk,
+        }, {    /* UART2 */
+                .dev_id         = "dev:f3",
+                .clk            = &ref24_clk,
+        }, {    /* UART3 */
+                .dev_id         = "fpga:09",
+                .clk            = &ref24_clk,
+        }, {    /* KMI0 */
+                .dev_id         = "fpga:06",
+                .clk            = &ref24_clk,
+        }, {    /* KMI1 */
+                .dev_id         = "fpga:07",
+                .clk            = &ref24_clk,
+        }, {    /* MMC0 */
+                .dev_id         = "fpga:05",
+                .clk            = &ref24_clk,
+        }, {    /* MMC1 */
+                .dev_id         = "fpga:0b",
+                .clk            = &ref24_clk,
+        }, {    /* CLCD */
+                .dev_id         = "dev:20",
+                .clk            = &osc4_clk,
+        }
 };
 
 /*
@@ -786,7 +825,8 @@ void __init versatile_init(void)
 {
         int i;
 
-        clk_register(&versatile_clcd_clk);
+        for (i = 0; i < ARRAY_SIZE(lookups); i++)
+                clkdev_add(&lookups[i]);
 
         platform_device_register(&versatile_flash_device);
         platform_device_register(&versatile_i2c_device);
diff --git a/arch/arm/mach-versatile/include/mach/clkdev.h b/arch/arm/mach-versatile/include/mach/clkdev.h
new file mode 100644
index 00000000000..04b37a89801
--- /dev/null
+++ b/arch/arm/mach-versatile/include/mach/clkdev.h
@@ -0,0 +1,7 @@
+#ifndef __ASM_MACH_CLKDEV_H
+#define __ASM_MACH_CLKDEV_H
+
+#define __clk_get(clk) ({ 1; })
+#define __clk_put(clk) do { } while (0)
+
+#endif