diff options
author | Paul Walmsley <paul@pwsan.com> | 2009-07-24 19:44:03 -0600 |
---|---|---|
committer | paul <paul@twilight.(none)> | 2009-07-24 20:10:35 -0600 |
commit | 72350b29a4c0debfc27c2edbeed9b4ff3f935dd4 (patch) | |
tree | 0c4637987fdbe97bfbdab7e00031283af47aadc1 /arch/arm/mach-omap2/clock.c | |
parent | df56556e571234cf26072cd58c01ac3520986b44 (diff) | |
download | linux-72350b29a4c0debfc27c2edbeed9b4ff3f935dd4.tar.bz2 |
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>
Diffstat (limited to 'arch/arm/mach-omap2/clock.c')
-rw-r--r-- | arch/arm/mach-omap2/clock.c | 156 |
1 files changed, 79 insertions, 77 deletions
diff --git a/arch/arm/mach-omap2/clock.c b/arch/arm/mach-omap2/clock.c index b0665f161c03..456e2ad5f621 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 @@ unsigned long omap2_fixed_divisor_recalc(struct clk *clk) } /** - * 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 + * + * 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 * - * Returns 1 if the clock enabled in time, or 0 if it failed to enable - * in roughly MAX_CLOCK_ENABLE_WAIT microseconds. + * 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. */ -int omap2_wait_clock_ready(void __iomem *reg, u32 mask, const char *name) +void omap2_clk_dflt_find_companion(struct clk *clk, void __iomem **other_reg, + u8 *other_bit) { - int i = 0; - int ena = 0; + u32 r; /* - * 24xx uses 0 to indicate not ready, and 1 to indicate ready. - * 34xx reverses this, just to keep us on our toes + * Convert CM_ICLKEN* <-> CM_FCLKEN*. This conversion assumes + * it's just a matter of XORing the bits. */ - 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; -}; + r = ((__force u32)clk->enable_reg ^ (CM_FCLKEN ^ CM_ICLKEN)); + *other_reg = (__force void __iomem *)r; + *other_bit = clk->enable_bit; +} -/* - * 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 +/** + * 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. */ -static void omap2_clk_wait_ready(struct clk *clk) +void omap2_clk_dflt_find_idlest(struct clk *clk, void __iomem **idlest_reg, + u8 *idlest_bit) { - void __iomem *reg, *other_reg, *st_reg; - u32 bit; + u32 r; - /* - * 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; + r = (((__force u32)clk->enable_reg & ~0xf0) | 0x20); + *idlest_reg = (__force void __iomem *)r; + *idlest_bit = clk->enable_bit; +} - /* - * 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)); +/** + * 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; + } - /* 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* */ + clk->ops->find_idlest(clk, &idlest_reg, &idlest_bit); - omap2_wait_clock_ready(st_reg, bit, clk->name); + omap2_cm_wait_idlest(idlest_reg, (1 << idlest_bit), clk->name); } -static int omap2_dflt_clk_enable(struct clk *clk) +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 @@ static int omap2_dflt_clk_enable(struct clk *clk) __raw_writel(v, clk->enable_reg); v = __raw_readl(clk->enable_reg); /* OCP barrier */ - return 0; -} + if (clk->ops->find_idlest) + omap2_module_wait_ready(clk); -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; + return 0; } -static void omap2_dflt_clk_disable(struct clk *clk) +void omap2_dflt_clk_disable(struct clk *clk) { u32 v; @@ -406,8 +406,10 @@ static void omap2_dflt_clk_disable(struct clk *clk) } 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 = { |