diff options
Diffstat (limited to 'arch/mips/kernel/cpufreq/loongson2_clock.c')
| -rw-r--r-- | arch/mips/kernel/cpufreq/loongson2_clock.c | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/arch/mips/kernel/cpufreq/loongson2_clock.c b/arch/mips/kernel/cpufreq/loongson2_clock.c new file mode 100644 index 00000000000..d7ca256e33e --- /dev/null +++ b/arch/mips/kernel/cpufreq/loongson2_clock.c @@ -0,0 +1,166 @@ +/* + * Copyright (C) 2006 - 2008 Lemote Inc. & Insititute of Computing Technology + * Author: Yanhua, yanh@lemote.com + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + */ + +#include <linux/cpufreq.h> +#include <linux/platform_device.h> + +#include <asm/clock.h> + +#include <loongson.h> + +static LIST_HEAD(clock_list); +static DEFINE_SPINLOCK(clock_lock); +static DEFINE_MUTEX(clock_list_sem); + +/* Minimum CLK support */ +enum { + DC_ZERO, DC_25PT = 2, DC_37PT, DC_50PT, DC_62PT, DC_75PT, + DC_87PT, DC_DISABLE, DC_RESV +}; + +struct cpufreq_frequency_table loongson2_clockmod_table[] = { + {DC_RESV, CPUFREQ_ENTRY_INVALID}, + {DC_ZERO, CPUFREQ_ENTRY_INVALID}, + {DC_25PT, 0}, + {DC_37PT, 0}, + {DC_50PT, 0}, + {DC_62PT, 0}, + {DC_75PT, 0}, + {DC_87PT, 0}, + {DC_DISABLE, 0}, + {DC_RESV, CPUFREQ_TABLE_END}, +}; +EXPORT_SYMBOL_GPL(loongson2_clockmod_table); + +static struct clk cpu_clk = { + .name = "cpu_clk", + .flags = CLK_ALWAYS_ENABLED | CLK_RATE_PROPAGATES, + .rate = 800000000, +}; + +struct clk *clk_get(struct device *dev, const char *id) +{ + return &cpu_clk; +} +EXPORT_SYMBOL(clk_get); + +static void propagate_rate(struct clk *clk) +{ + struct clk *clkp; + + list_for_each_entry(clkp, &clock_list, node) { + if (likely(clkp->parent != clk)) + continue; + if (likely(clkp->ops && clkp->ops->recalc)) + clkp->ops->recalc(clkp); + if (unlikely(clkp->flags & CLK_RATE_PROPAGATES)) + propagate_rate(clkp); + } +} + +int clk_enable(struct clk *clk) +{ + return 0; +} +EXPORT_SYMBOL(clk_enable); + +void clk_disable(struct clk *clk) +{ +} +EXPORT_SYMBOL(clk_disable); + +unsigned long clk_get_rate(struct clk *clk) +{ + return (unsigned long)clk->rate; +} +EXPORT_SYMBOL(clk_get_rate); + +void clk_put(struct clk *clk) +{ +} +EXPORT_SYMBOL(clk_put); + +int clk_set_rate(struct clk *clk, unsigned long rate) +{ + return clk_set_rate_ex(clk, rate, 0); +} +EXPORT_SYMBOL_GPL(clk_set_rate); + +int clk_set_rate_ex(struct clk *clk, unsigned long rate, int algo_id) +{ + int ret = 0; + int regval; + int i; + + if (likely(clk->ops && clk->ops->set_rate)) { + unsigned long flags; + + spin_lock_irqsave(&clock_lock, flags); + ret = clk->ops->set_rate(clk, rate, algo_id); + spin_unlock_irqrestore(&clock_lock, flags); + } + + if (unlikely(clk->flags & CLK_RATE_PROPAGATES)) + propagate_rate(clk); + + for (i = 0; loongson2_clockmod_table[i].frequency != CPUFREQ_TABLE_END; + i++) { + if (loongson2_clockmod_table[i].frequency == + CPUFREQ_ENTRY_INVALID) + continue; + if (rate == loongson2_clockmod_table[i].frequency) + break; + } + if (rate != loongson2_clockmod_table[i].frequency) + return -ENOTSUPP; + + clk->rate = rate; + + regval = LOONGSON_CHIPCFG0; + regval = (regval & ~0x7) | (loongson2_clockmod_table[i].index - 1); + LOONGSON_CHIPCFG0 = regval; + + return ret; +} +EXPORT_SYMBOL_GPL(clk_set_rate_ex); + +long clk_round_rate(struct clk *clk, unsigned long rate) +{ + if (likely(clk->ops && clk->ops->round_rate)) { + unsigned long flags, rounded; + + spin_lock_irqsave(&clock_lock, flags); + rounded = clk->ops->round_rate(clk, rate); + spin_unlock_irqrestore(&clock_lock, flags); + + return rounded; + } + + return rate; +} +EXPORT_SYMBOL_GPL(clk_round_rate); + +/* + * This is the simple version of Loongson-2 wait, Maybe we need do this in + * interrupt disabled content + */ + +DEFINE_SPINLOCK(loongson2_wait_lock); +void loongson2_cpu_wait(void) +{ + u32 cpu_freq; + unsigned long flags; + + spin_lock_irqsave(&loongson2_wait_lock, flags); + cpu_freq = LOONGSON_CHIPCFG0; + LOONGSON_CHIPCFG0 &= ~0x7; /* Put CPU into wait mode */ + LOONGSON_CHIPCFG0 = cpu_freq; /* Restore CPU state */ + spin_unlock_irqrestore(&loongson2_wait_lock, flags); +} +EXPORT_SYMBOL_GPL(loongson2_cpu_wait); |