diff options
Diffstat (limited to 'arch/arm/mach-davinci/clock.c')
| -rw-r--r-- | arch/arm/mach-davinci/clock.c | 495 |
1 files changed, 404 insertions, 91 deletions
diff --git a/arch/arm/mach-davinci/clock.c b/arch/arm/mach-davinci/clock.c index 83d54d50b5e..985e5fd00fb 100644 --- a/arch/arm/mach-davinci/clock.c +++ b/arch/arm/mach-davinci/clock.c @@ -17,11 +17,12 @@ #include <linux/clk.h> #include <linux/err.h> #include <linux/mutex.h> -#include <linux/platform_device.h> #include <linux/io.h> +#include <linux/delay.h> #include <mach/hardware.h> +#include <mach/clock.h> #include <mach/psc.h> #include <mach/cputype.h> #include "clock.h" @@ -30,33 +31,68 @@ static LIST_HEAD(clocks); static DEFINE_MUTEX(clocks_mutex); static DEFINE_SPINLOCK(clockfw_lock); -static unsigned psc_domain(struct clk *clk) -{ - return (clk->flags & PSC_DSP) - ? DAVINCI_GPSC_DSPDOMAIN - : DAVINCI_GPSC_ARMDOMAIN; -} - static void __clk_enable(struct clk *clk) { if (clk->parent) __clk_enable(clk->parent); - if (clk->usecount++ == 0 && (clk->flags & CLK_PSC)) - davinci_psc_config(psc_domain(clk), clk->psc_ctlr, - clk->lpsc, 1); + if (clk->usecount++ == 0) { + if (clk->flags & CLK_PSC) + davinci_psc_config(clk->domain, clk->gpsc, clk->lpsc, + true, clk->flags); + else if (clk->clk_enable) + clk->clk_enable(clk); + } } static void __clk_disable(struct clk *clk) { if (WARN_ON(clk->usecount == 0)) return; - if (--clk->usecount == 0 && !(clk->flags & CLK_PLL)) - davinci_psc_config(psc_domain(clk), clk->psc_ctlr, - clk->lpsc, 0); + if (--clk->usecount == 0) { + if (!(clk->flags & CLK_PLL) && (clk->flags & CLK_PSC)) + davinci_psc_config(clk->domain, clk->gpsc, clk->lpsc, + false, clk->flags); + else if (clk->clk_disable) + clk->clk_disable(clk); + } if (clk->parent) __clk_disable(clk->parent); } +int davinci_clk_reset(struct clk *clk, bool reset) +{ + unsigned long flags; + + if (clk == NULL || IS_ERR(clk)) + return -EINVAL; + + spin_lock_irqsave(&clockfw_lock, flags); + if (clk->flags & CLK_PSC) + davinci_psc_reset(clk->gpsc, clk->lpsc, reset); + spin_unlock_irqrestore(&clockfw_lock, flags); + + return 0; +} +EXPORT_SYMBOL(davinci_clk_reset); + +int davinci_clk_reset_assert(struct clk *clk) +{ + if (clk == NULL || IS_ERR(clk) || !clk->reset) + return -EINVAL; + + return clk->reset(clk, true); +} +EXPORT_SYMBOL(davinci_clk_reset_assert); + +int davinci_clk_reset_deassert(struct clk *clk) +{ + if (clk == NULL || IS_ERR(clk) || !clk->reset) + return -EINVAL; + + return clk->reset(clk, false); +} +EXPORT_SYMBOL(davinci_clk_reset_deassert); + int clk_enable(struct clk *clk) { unsigned long flags; @@ -97,22 +133,77 @@ EXPORT_SYMBOL(clk_get_rate); long clk_round_rate(struct clk *clk, unsigned long rate) { if (clk == NULL || IS_ERR(clk)) - return -EINVAL; + return 0; + + if (clk->round_rate) + return clk->round_rate(clk, rate); return clk->rate; } EXPORT_SYMBOL(clk_round_rate); +/* Propagate rate to children */ +static void propagate_rate(struct clk *root) +{ + struct clk *clk; + + list_for_each_entry(clk, &root->children, childnode) { + if (clk->recalc) + clk->rate = clk->recalc(clk); + propagate_rate(clk); + } +} + int clk_set_rate(struct clk *clk, unsigned long rate) { + unsigned long flags; + int ret = -EINVAL; + if (clk == NULL || IS_ERR(clk)) - return -EINVAL; + return ret; + + if (clk->set_rate) + ret = clk->set_rate(clk, rate); - /* changing the clk rate is not supported */ - return -EINVAL; + spin_lock_irqsave(&clockfw_lock, flags); + if (ret == 0) { + if (clk->recalc) + clk->rate = clk->recalc(clk); + propagate_rate(clk); + } + spin_unlock_irqrestore(&clockfw_lock, flags); + + return ret; } EXPORT_SYMBOL(clk_set_rate); +int clk_set_parent(struct clk *clk, struct clk *parent) +{ + unsigned long flags; + + if (clk == NULL || IS_ERR(clk)) + return -EINVAL; + + /* Cannot change parent on enabled clock */ + if (WARN_ON(clk->usecount)) + return -EINVAL; + + mutex_lock(&clocks_mutex); + clk->parent = parent; + list_del_init(&clk->childnode); + list_add(&clk->childnode, &clk->parent->children); + mutex_unlock(&clocks_mutex); + + spin_lock_irqsave(&clockfw_lock, flags); + if (clk->recalc) + clk->rate = clk->recalc(clk); + propagate_rate(clk); + spin_unlock_irqrestore(&clockfw_lock, flags); + + return 0; +} +EXPORT_SYMBOL(clk_set_parent); + int clk_register(struct clk *clk) { if (clk == NULL || IS_ERR(clk)) @@ -123,16 +214,24 @@ int clk_register(struct clk *clk) clk->name, clk->parent->name)) return -EINVAL; + INIT_LIST_HEAD(&clk->children); + mutex_lock(&clocks_mutex); list_add_tail(&clk->node, &clocks); + if (clk->parent) + list_add_tail(&clk->childnode, &clk->parent->children); mutex_unlock(&clocks_mutex); /* If rate is already set, use it */ if (clk->rate) return 0; + /* Else, see if there is a way to calculate it */ + if (clk->recalc) + clk->rate = clk->recalc(clk); + /* Otherwise, default to parent rate */ - if (clk->parent) + else if (clk->parent) clk->rate = clk->parent->rate; return 0; @@ -146,6 +245,7 @@ void clk_unregister(struct clk *clk) mutex_lock(&clocks_mutex); list_del(&clk->node); + list_del(&clk->childnode); mutex_unlock(&clocks_mutex); } EXPORT_SYMBOL(clk_unregister); @@ -154,7 +254,7 @@ EXPORT_SYMBOL(clk_unregister); /* * Disable any unused clocks left on by the bootloader */ -static int __init clk_disable_unused(void) +int __init davinci_clk_disable_unused(void) { struct clk *ck; @@ -166,63 +266,154 @@ static int __init clk_disable_unused(void) continue; /* ignore if in Disabled or SwRstDisable states */ - if (!davinci_psc_is_clk_active(ck->psc_ctlr, ck->lpsc)) + if (!davinci_psc_is_clk_active(ck->gpsc, ck->lpsc)) continue; - pr_info("Clocks: disable unused %s\n", ck->name); - davinci_psc_config(psc_domain(ck), ck->psc_ctlr, ck->lpsc, 0); + pr_debug("Clocks: disable unused %s\n", ck->name); + + davinci_psc_config(ck->domain, ck->gpsc, ck->lpsc, + false, ck->flags); } spin_unlock_irq(&clockfw_lock); return 0; } -late_initcall(clk_disable_unused); #endif -static void clk_sysclk_recalc(struct clk *clk) +static unsigned long clk_sysclk_recalc(struct clk *clk) { u32 v, plldiv; struct pll_data *pll; + unsigned long rate = clk->rate; /* If this is the PLL base clock, no more calculations needed */ if (clk->pll_data) - return; + return rate; if (WARN_ON(!clk->parent)) - return; + return rate; - clk->rate = clk->parent->rate; + rate = clk->parent->rate; /* Otherwise, the parent must be a PLL */ if (WARN_ON(!clk->parent->pll_data)) - return; + return rate; pll = clk->parent->pll_data; /* If pre-PLL, source clock is before the multiplier and divider(s) */ if (clk->flags & PRE_PLL) - clk->rate = pll->input_rate; + rate = pll->input_rate; if (!clk->div_reg) - return; + return rate; v = __raw_readl(pll->base + clk->div_reg); if (v & PLLDIV_EN) { - plldiv = (v & PLLDIV_RATIO_MASK) + 1; + plldiv = (v & pll->div_ratio_mask) + 1; if (plldiv) - clk->rate /= plldiv; + rate /= plldiv; + } + + return rate; +} + +int davinci_set_sysclk_rate(struct clk *clk, unsigned long rate) +{ + unsigned v; + struct pll_data *pll; + unsigned long input; + unsigned ratio = 0; + + /* If this is the PLL base clock, wrong function to call */ + if (clk->pll_data) + return -EINVAL; + + /* There must be a parent... */ + if (WARN_ON(!clk->parent)) + return -EINVAL; + + /* ... the parent must be a PLL... */ + if (WARN_ON(!clk->parent->pll_data)) + return -EINVAL; + + /* ... and this clock must have a divider. */ + if (WARN_ON(!clk->div_reg)) + return -EINVAL; + + pll = clk->parent->pll_data; + + input = clk->parent->rate; + + /* If pre-PLL, source clock is before the multiplier and divider(s) */ + if (clk->flags & PRE_PLL) + input = pll->input_rate; + + if (input > rate) { + /* + * Can afford to provide an output little higher than requested + * only if maximum rate supported by hardware on this sysclk + * is known. + */ + if (clk->maxrate) { + ratio = DIV_ROUND_CLOSEST(input, rate); + if (input / ratio > clk->maxrate) + ratio = 0; + } + + if (ratio == 0) + ratio = DIV_ROUND_UP(input, rate); + + ratio--; } + + if (ratio > pll->div_ratio_mask) + return -EINVAL; + + do { + v = __raw_readl(pll->base + PLLSTAT); + } while (v & PLLSTAT_GOSTAT); + + v = __raw_readl(pll->base + clk->div_reg); + v &= ~pll->div_ratio_mask; + v |= ratio | PLLDIV_EN; + __raw_writel(v, pll->base + clk->div_reg); + + v = __raw_readl(pll->base + PLLCMD); + v |= PLLCMD_GOSET; + __raw_writel(v, pll->base + PLLCMD); + + do { + v = __raw_readl(pll->base + PLLSTAT); + } while (v & PLLSTAT_GOSTAT); + + return 0; +} +EXPORT_SYMBOL(davinci_set_sysclk_rate); + +static unsigned long clk_leafclk_recalc(struct clk *clk) +{ + if (WARN_ON(!clk->parent)) + return clk->rate; + + return clk->parent->rate; } -static void __init clk_pll_init(struct clk *clk) +int davinci_simple_set_rate(struct clk *clk, unsigned long rate) +{ + clk->rate = rate; + return 0; +} + +static unsigned long clk_pllclk_recalc(struct clk *clk) { u32 ctrl, mult = 1, prediv = 1, postdiv = 1; u8 bypass; struct pll_data *pll = clk->pll_data; + unsigned long rate = clk->rate; - pll->base = IO_ADDRESS(pll->phys_base); ctrl = __raw_readl(pll->base + PLLCTL); - clk->rate = pll->input_rate = clk->parent->rate; + rate = pll->input_rate = clk->parent->rate; if (ctrl & PLLCTL_PLLEN) { bypass = 0; @@ -237,7 +428,7 @@ static void __init clk_pll_init(struct clk *clk) if (pll->flags & PLL_HAS_PREDIV) { prediv = __raw_readl(pll->base + PREDIV); if (prediv & PLLDIV_EN) - prediv = (prediv & PLLDIV_RATIO_MASK) + 1; + prediv = (prediv & pll->div_ratio_mask) + 1; else prediv = 1; } @@ -249,15 +440,15 @@ static void __init clk_pll_init(struct clk *clk) if (pll->flags & PLL_HAS_POSTDIV) { postdiv = __raw_readl(pll->base + POSTDIV); if (postdiv & PLLDIV_EN) - postdiv = (postdiv & PLLDIV_RATIO_MASK) + 1; + postdiv = (postdiv & pll->div_ratio_mask) + 1; else postdiv = 1; } if (!bypass) { - clk->rate /= prediv; - clk->rate *= mult; - clk->rate /= postdiv; + rate /= prediv; + rate *= mult; + rate /= postdiv; } pr_debug("PLL%d: input = %lu MHz [ ", @@ -270,56 +461,182 @@ static void __init clk_pll_init(struct clk *clk) pr_debug("* %d ", mult); if (postdiv > 1) pr_debug("/ %d ", postdiv); - pr_debug("] --> %lu MHz output.\n", clk->rate / 1000000); + pr_debug("] --> %lu MHz output.\n", rate / 1000000); + + return rate; } -int __init davinci_clk_init(struct davinci_clk *clocks) - { - struct davinci_clk *c; +/** + * davinci_set_pllrate - set the output rate of a given PLL. + * + * Note: Currently tested to work with OMAP-L138 only. + * + * @pll: pll whose rate needs to be changed. + * @prediv: The pre divider value. Passing 0 disables the pre-divider. + * @pllm: The multiplier value. Passing 0 leads to multiply-by-one. + * @postdiv: The post divider value. Passing 0 disables the post-divider. + */ +int davinci_set_pllrate(struct pll_data *pll, unsigned int prediv, + unsigned int mult, unsigned int postdiv) +{ + u32 ctrl; + unsigned int locktime; + unsigned long flags; + + if (pll->base == NULL) + return -EINVAL; + + /* + * PLL lock time required per OMAP-L138 datasheet is + * (2000 * prediv)/sqrt(pllm) OSCIN cycles. We approximate sqrt(pllm) + * as 4 and OSCIN cycle as 25 MHz. + */ + if (prediv) { + locktime = ((2000 * prediv) / 100); + prediv = (prediv - 1) | PLLDIV_EN; + } else { + locktime = PLL_LOCK_TIME; + } + if (postdiv) + postdiv = (postdiv - 1) | PLLDIV_EN; + if (mult) + mult = mult - 1; + + /* Protect against simultaneous calls to PLL setting seqeunce */ + spin_lock_irqsave(&clockfw_lock, flags); + + ctrl = __raw_readl(pll->base + PLLCTL); + + /* Switch the PLL to bypass mode */ + ctrl &= ~(PLLCTL_PLLENSRC | PLLCTL_PLLEN); + __raw_writel(ctrl, pll->base + PLLCTL); + + udelay(PLL_BYPASS_TIME); + + /* Reset and enable PLL */ + ctrl &= ~(PLLCTL_PLLRST | PLLCTL_PLLDIS); + __raw_writel(ctrl, pll->base + PLLCTL); + + if (pll->flags & PLL_HAS_PREDIV) + __raw_writel(prediv, pll->base + PREDIV); + + __raw_writel(mult, pll->base + PLLM); + + if (pll->flags & PLL_HAS_POSTDIV) + __raw_writel(postdiv, pll->base + POSTDIV); + + udelay(PLL_RESET_TIME); + + /* Bring PLL out of reset */ + ctrl |= PLLCTL_PLLRST; + __raw_writel(ctrl, pll->base + PLLCTL); + + udelay(locktime); + + /* Remove PLL from bypass mode */ + ctrl |= PLLCTL_PLLEN; + __raw_writel(ctrl, pll->base + PLLCTL); + + spin_unlock_irqrestore(&clockfw_lock, flags); + + return 0; +} +EXPORT_SYMBOL(davinci_set_pllrate); + +/** + * davinci_set_refclk_rate() - Set the reference clock rate + * @rate: The new rate. + * + * Sets the reference clock rate to a given value. This will most likely + * result in the entire clock tree getting updated. + * + * This is used to support boards which use a reference clock different + * than that used by default in <soc>.c file. The reference clock rate + * should be updated early in the boot process; ideally soon after the + * clock tree has been initialized once with the default reference clock + * rate (davinci_common_init()). + * + * Returns 0 on success, error otherwise. + */ +int davinci_set_refclk_rate(unsigned long rate) +{ + struct clk *refclk; + + refclk = clk_get(NULL, "ref"); + if (IS_ERR(refclk)) { + pr_err("%s: failed to get reference clock.\n", __func__); + return PTR_ERR(refclk); + } + + clk_set_rate(refclk, rate); + + clk_put(refclk); + + return 0; +} + +int __init davinci_clk_init(struct clk_lookup *clocks) +{ + struct clk_lookup *c; struct clk *clk; + size_t num_clocks = 0; - for (c = clocks; c->lk.clk; c++) { - clk = c->lk.clk; + for (c = clocks; c->clk; c++) { + clk = c->clk; - if (clk->pll_data) - clk_pll_init(clk); + if (!clk->recalc) { - /* Calculate rates for PLL-derived clocks */ - else if (clk->flags & CLK_PLL) - clk_sysclk_recalc(clk); + /* Check if clock is a PLL */ + if (clk->pll_data) + clk->recalc = clk_pllclk_recalc; + + /* Else, if it is a PLL-derived clock */ + else if (clk->flags & CLK_PLL) + clk->recalc = clk_sysclk_recalc; + + /* Otherwise, it is a leaf clock (PSC clock) */ + else if (clk->parent) + clk->recalc = clk_leafclk_recalc; + } + + if (clk->pll_data) { + struct pll_data *pll = clk->pll_data; + + if (!pll->div_ratio_mask) + pll->div_ratio_mask = PLLDIV_RATIO_MASK; + + if (pll->phys_base && !pll->base) { + pll->base = ioremap(pll->phys_base, SZ_4K); + WARN_ON(!pll->base); + } + } + + if (clk->recalc) + clk->rate = clk->recalc(clk); if (clk->lpsc) clk->flags |= CLK_PSC; - clkdev_add(&c->lk); + if (clk->flags & PSC_LRST) + clk->reset = davinci_clk_reset; + clk_register(clk); + num_clocks++; /* Turn on clocks that Linux doesn't otherwise manage */ if (clk->flags & ALWAYS_ENABLED) clk_enable(clk); } - return 0; -} - -#ifdef CONFIG_PROC_FS -#include <linux/proc_fs.h> -#include <linux/seq_file.h> + clkdev_add_table(clocks, num_clocks); -static void *davinci_ck_start(struct seq_file *m, loff_t *pos) -{ - return *pos < 1 ? (void *)1 : NULL; + return 0; } -static void *davinci_ck_next(struct seq_file *m, void *v, loff_t *pos) -{ - ++*pos; - return NULL; -} +#ifdef CONFIG_DEBUG_FS -static void davinci_ck_stop(struct seq_file *m, void *v) -{ -} +#include <linux/debugfs.h> +#include <linux/seq_file.h> #define CLKNAME_MAX 10 /* longest clock name */ #define NEST_DELTA 2 @@ -352,49 +669,45 @@ dump_clock(struct seq_file *s, unsigned nest, struct clk *parent) /* REVISIT show device associations too */ /* cost is now small, but not linear... */ - list_for_each_entry(clk, &clocks, node) { - if (clk->parent == parent) - dump_clock(s, nest + NEST_DELTA, clk); + list_for_each_entry(clk, &parent->children, childnode) { + dump_clock(s, nest + NEST_DELTA, clk); } } static int davinci_ck_show(struct seq_file *m, void *v) { - /* Show clock tree; we know the main oscillator is first. - * We trust nonzero usecounts equate to PSC enables... + struct clk *clk; + + /* + * Show clock tree; We trust nonzero usecounts equate to PSC enables... */ mutex_lock(&clocks_mutex); - if (!list_empty(&clocks)) - dump_clock(m, 0, list_first_entry(&clocks, struct clk, node)); + list_for_each_entry(clk, &clocks, node) + if (!clk->parent) + dump_clock(m, 0, clk); mutex_unlock(&clocks_mutex); return 0; } -static const struct seq_operations davinci_ck_op = { - .start = davinci_ck_start, - .next = davinci_ck_next, - .stop = davinci_ck_stop, - .show = davinci_ck_show -}; - static int davinci_ck_open(struct inode *inode, struct file *file) { - return seq_open(file, &davinci_ck_op); + return single_open(file, davinci_ck_show, NULL); } -static const struct file_operations proc_davinci_ck_operations = { +static const struct file_operations davinci_ck_operations = { .open = davinci_ck_open, .read = seq_read, .llseek = seq_lseek, - .release = seq_release, + .release = single_release, }; -static int __init davinci_ck_proc_init(void) +static int __init davinci_clk_debugfs_init(void) { - proc_create("davinci_clocks", 0, NULL, &proc_davinci_ck_operations); + debugfs_create_file("davinci_clocks", S_IFREG | S_IRUGO, NULL, NULL, + &davinci_ck_operations); return 0; } -__initcall(davinci_ck_proc_init); -#endif /* CONFIG_DEBUG_PROC_FS */ +device_initcall(davinci_clk_debugfs_init); +#endif /* CONFIG_DEBUG_FS */ |
