OMAP2/3 clock: split, rename omap2_wait_clock_ready()
Some OMAP2/3 hardware modules have CM_IDLEST attributes that are not
handled by the current omap2_wait_clock_ready() code. In preparation
for patches that fix the unusual devices, rename the function
omap2_wait_clock_ready() to omap2_wait_module_ready() and split it
into three parts:
1. A clkops-specific companion clock return function (by default,
omap2_clk_dflt_find_companion())
2. A clkops-specific CM_IDLEST register address and bit shift return
function (by default, omap2_clk_dflt_find_idlest())
3. Code to wait for the CM to indicate that the module is ready
(omap2_cm_wait_idlest())
Clocks can now specify their own custom find_companion() and find_idlest()
functions; used in subsequent patches.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
diff --git a/arch/arm/mach-omap2/clock.c b/arch/arm/mach-omap2/clock.c
index b0665f1..456e2ad 100644
--- a/arch/arm/mach-omap2/clock.c
+++ b/arch/arm/mach-omap2/clock.c
@@ -27,6 +27,7 @@
#include <mach/clock.h>
#include <mach/clockdomain.h>
#include <mach/cpu.h>
+#include <mach/prcm.h>
#include <asm/div64.h>
#include <mach/sdrc.h>
@@ -38,8 +39,6 @@
#include "cm-regbits-24xx.h"
#include "cm-regbits-34xx.h"
-#define MAX_CLOCK_ENABLE_WAIT 100000
-
/* DPLL rate rounding: minimum DPLL multiplier, divider values */
#define DPLL_MIN_MULTIPLIER 1
#define DPLL_MIN_DIVIDER 1
@@ -274,83 +273,97 @@
}
/**
- * omap2_wait_clock_ready - wait for clock to enable
- * @reg: physical address of clock IDLEST register
- * @mask: value to mask against to determine if the clock is active
- * @name: name of the clock (for printk)
+ * omap2_clk_dflt_find_companion - find companion clock to @clk
+ * @clk: struct clk * to find the companion clock of
+ * @other_reg: void __iomem ** to return the companion clock CM_*CLKEN va in
+ * @other_bit: u8 ** to return the companion clock bit shift in
*
- * Returns 1 if the clock enabled in time, or 0 if it failed to enable
- * in roughly MAX_CLOCK_ENABLE_WAIT microseconds.
- */
-int omap2_wait_clock_ready(void __iomem *reg, u32 mask, const char *name)
-{
- int i = 0;
- int ena = 0;
-
- /*
- * 24xx uses 0 to indicate not ready, and 1 to indicate ready.
- * 34xx reverses this, just to keep us on our toes
- */
- if (cpu_mask & (RATE_IN_242X | RATE_IN_243X))
- ena = mask;
- else if (cpu_mask & RATE_IN_343X)
- ena = 0;
-
- /* Wait for lock */
- while (((__raw_readl(reg) & mask) != ena) &&
- (i++ < MAX_CLOCK_ENABLE_WAIT)) {
- udelay(1);
- }
-
- if (i <= MAX_CLOCK_ENABLE_WAIT)
- pr_debug("Clock %s stable after %d loops\n", name, i);
- else
- printk(KERN_ERR "Clock %s didn't enable in %d tries\n",
- name, MAX_CLOCK_ENABLE_WAIT);
-
-
- return (i < MAX_CLOCK_ENABLE_WAIT) ? 1 : 0;
-};
-
-
-/*
- * Note: We don't need special code here for INVERT_ENABLE
- * for the time being since INVERT_ENABLE only applies to clocks enabled by
+ * Note: We don't need special code here for INVERT_ENABLE for the
+ * time being since INVERT_ENABLE only applies to clocks enabled by
* CM_CLKEN_PLL
+ *
+ * Convert CM_ICLKEN* <-> CM_FCLKEN*. This conversion assumes it's
+ * just a matter of XORing the bits.
+ *
+ * Some clocks don't have companion clocks. For example, modules with
+ * only an interface clock (such as MAILBOXES) don't have a companion
+ * clock. Right now, this code relies on the hardware exporting a bit
+ * in the correct companion register that indicates that the
+ * nonexistent 'companion clock' is active. Future patches will
+ * associate this type of code with per-module data structures to
+ * avoid this issue, and remove the casts. No return value.
*/
-static void omap2_clk_wait_ready(struct clk *clk)
+void omap2_clk_dflt_find_companion(struct clk *clk, void __iomem **other_reg,
+ u8 *other_bit)
{
- void __iomem *reg, *other_reg, *st_reg;
- u32 bit;
-
- /*
- * REVISIT: This code is pretty ugly. It would be nice to generalize
- * it and pull it into struct clk itself somehow.
- */
- reg = clk->enable_reg;
+ u32 r;
/*
* Convert CM_ICLKEN* <-> CM_FCLKEN*. This conversion assumes
* it's just a matter of XORing the bits.
*/
- other_reg = (void __iomem *)((u32)reg ^ (CM_FCLKEN ^ CM_ICLKEN));
+ r = ((__force u32)clk->enable_reg ^ (CM_FCLKEN ^ CM_ICLKEN));
- /* Check if both functional and interface clocks
- * are running. */
- bit = 1 << clk->enable_bit;
- if (!(__raw_readl(other_reg) & bit))
- return;
- st_reg = (void __iomem *)(((u32)other_reg & ~0xf0) | 0x20); /* CM_IDLEST* */
-
- omap2_wait_clock_ready(st_reg, bit, clk->name);
+ *other_reg = (__force void __iomem *)r;
+ *other_bit = clk->enable_bit;
}
-static int omap2_dflt_clk_enable(struct clk *clk)
+/**
+ * omap2_clk_dflt_find_idlest - find CM_IDLEST reg va, bit shift for @clk
+ * @clk: struct clk * to find IDLEST info for
+ * @idlest_reg: void __iomem ** to return the CM_IDLEST va in
+ * @idlest_bit: u8 ** to return the CM_IDLEST bit shift in
+ *
+ * Return the CM_IDLEST register address and bit shift corresponding
+ * to the module that "owns" this clock. This default code assumes
+ * that the CM_IDLEST bit shift is the CM_*CLKEN bit shift, and that
+ * the IDLEST register address ID corresponds to the CM_*CLKEN
+ * register address ID (e.g., that CM_FCLKEN2 corresponds to
+ * CM_IDLEST2). This is not true for all modules. No return value.
+ */
+void omap2_clk_dflt_find_idlest(struct clk *clk, void __iomem **idlest_reg,
+ u8 *idlest_bit)
+{
+ u32 r;
+
+ r = (((__force u32)clk->enable_reg & ~0xf0) | 0x20);
+ *idlest_reg = (__force void __iomem *)r;
+ *idlest_bit = clk->enable_bit;
+}
+
+/**
+ * omap2_module_wait_ready - wait for an OMAP module to leave IDLE
+ * @clk: struct clk * belonging to the module
+ *
+ * If the necessary clocks for the OMAP hardware IP block that
+ * corresponds to clock @clk are enabled, then wait for the module to
+ * indicate readiness (i.e., to leave IDLE). This code does not
+ * belong in the clock code and will be moved in the medium term to
+ * module-dependent code. No return value.
+ */
+static void omap2_module_wait_ready(struct clk *clk)
+{
+ void __iomem *companion_reg, *idlest_reg;
+ u8 other_bit, idlest_bit;
+
+ /* Not all modules have multiple clocks that their IDLEST depends on */
+ if (clk->ops->find_companion) {
+ clk->ops->find_companion(clk, &companion_reg, &other_bit);
+ if (!(__raw_readl(companion_reg) & (1 << other_bit)))
+ return;
+ }
+
+ clk->ops->find_idlest(clk, &idlest_reg, &idlest_bit);
+
+ omap2_cm_wait_idlest(idlest_reg, (1 << idlest_bit), clk->name);
+}
+
+int omap2_dflt_clk_enable(struct clk *clk)
{
u32 v;
if (unlikely(clk->enable_reg == NULL)) {
- printk(KERN_ERR "clock.c: Enable for %s without enable code\n",
+ pr_err("clock.c: Enable for %s without enable code\n",
clk->name);
return 0; /* REVISIT: -EINVAL */
}
@@ -363,26 +376,13 @@
__raw_writel(v, clk->enable_reg);
v = __raw_readl(clk->enable_reg); /* OCP barrier */
+ if (clk->ops->find_idlest)
+ omap2_module_wait_ready(clk);
+
return 0;
}
-static int omap2_dflt_clk_enable_wait(struct clk *clk)
-{
- int ret;
-
- if (!clk->enable_reg) {
- printk(KERN_ERR "clock.c: Enable for %s without enable code\n",
- clk->name);
- return 0; /* REVISIT: -EINVAL */
- }
-
- ret = omap2_dflt_clk_enable(clk);
- if (ret == 0)
- omap2_clk_wait_ready(clk);
- return ret;
-}
-
-static void omap2_dflt_clk_disable(struct clk *clk)
+void omap2_dflt_clk_disable(struct clk *clk)
{
u32 v;
@@ -406,8 +406,10 @@
}
const struct clkops clkops_omap2_dflt_wait = {
- .enable = omap2_dflt_clk_enable_wait,
+ .enable = omap2_dflt_clk_enable,
.disable = omap2_dflt_clk_disable,
+ .find_companion = omap2_clk_dflt_find_companion,
+ .find_idlest = omap2_clk_dflt_find_idlest,
};
const struct clkops clkops_omap2_dflt = {