diff options
Diffstat (limited to 'target/linux/xburst/patches-3.8/0012-MIPS-JZ4740-Add-cpufreq-support.patch')
| -rw-r--r-- | target/linux/xburst/patches-3.8/0012-MIPS-JZ4740-Add-cpufreq-support.patch | 296 |
1 files changed, 296 insertions, 0 deletions
diff --git a/target/linux/xburst/patches-3.8/0012-MIPS-JZ4740-Add-cpufreq-support.patch b/target/linux/xburst/patches-3.8/0012-MIPS-JZ4740-Add-cpufreq-support.patch new file mode 100644 index 0000000000..54883ea77f --- /dev/null +++ b/target/linux/xburst/patches-3.8/0012-MIPS-JZ4740-Add-cpufreq-support.patch @@ -0,0 +1,296 @@ +From d0f0d5739a31c12d349980ed05a670fa1e84696d Mon Sep 17 00:00:00 2001 +From: Maarten ter Huurne <maarten@treewalker.org> +Date: Wed, 16 Mar 2011 03:16:04 +0100 +Subject: [PATCH 12/21] MIPS: JZ4740: Add cpufreq support. + +This is a squashed version of Uli's driver that was further developed in the opendingux-kernel repository. +--- + arch/mips/Kconfig | 1 + + arch/mips/jz4740/Makefile | 1 + + arch/mips/jz4740/cpufreq.c | 226 ++++++++++++++++++++++++++++++++++++++ + arch/mips/kernel/cpufreq/Kconfig | 13 ++- + 4 files changed, 240 insertions(+), 1 deletions(-) + create mode 100644 arch/mips/jz4740/cpufreq.c + +--- a/arch/mips/Kconfig ++++ b/arch/mips/Kconfig +@@ -228,6 +228,7 @@ config MACH_JZ4740 + select HAVE_PWM + select HAVE_CLK + select GENERIC_IRQ_CHIP ++ select CPU_SUPPORTS_CPUFREQ + + config LANTIQ + bool "Lantiq based platforms" +--- a/arch/mips/jz4740/Makefile ++++ b/arch/mips/jz4740/Makefile +@@ -16,3 +16,4 @@ obj-$(CONFIG_JZ4740_QI_LB60) += board-qi + # PM support + + obj-$(CONFIG_PM) += pm.o ++obj-$(CONFIG_CPU_FREQ_JZ) += cpufreq.o +--- /dev/null ++++ b/arch/mips/jz4740/cpufreq.c +@@ -0,0 +1,226 @@ ++/* ++ * linux/arch/mips/jz4740/cpufreq.c ++ * ++ * cpufreq driver for JZ4740 ++ * ++ * Copyright (c) 2010 Ulrich Hecht <ulrich.hecht@gmail.com> ++ * Copyright (c) 2010 Maarten ter Huurne <maarten@treewalker.org> ++ * ++ * This program is free software; you can redistribute it and/or modify ++ * it under the terms of the GNU General Public License version 2 as ++ * published by the Free Software Foundation. ++ */ ++ ++#include <linux/kernel.h> ++#include <linux/module.h> ++#include <linux/init.h> ++#include <linux/err.h> ++ ++#include <linux/cpufreq.h> ++ ++#include <linux/clk.h> ++#include <asm/mach-jz4740/base.h> ++ ++#include "clock.h" ++ ++#define DEBUG_CPUFREQ ++ ++#ifdef DEBUG_CPUFREQ ++#define dprintk(X...) printk(KERN_INFO X) ++#else ++#define dprintk(X...) do { } while(0) ++#endif ++ ++#define HCLK_MIN 30000 ++/* TODO: The maximum MCLK most likely depends on the SDRAM chips used, ++ so it is board-specific. */ ++#define MCLK_MAX 140000 ++ ++/* Same as jz_clk_main_divs, but with 24 and 32 removed because the hardware ++ spec states those dividers must not be used for CCLK or HCLK. */ ++static const unsigned int jz4740_freq_cpu_divs[] = {1, 2, 3, 4, 6, 8, 12, 16}; ++ ++struct jz4740_freq_percpu_info { ++ unsigned int pll_rate; ++ struct cpufreq_frequency_table table[ ++ ARRAY_SIZE(jz4740_freq_cpu_divs) + 1]; ++}; ++ ++static struct clk *pll; ++static struct clk *cclk; ++ ++static struct jz4740_freq_percpu_info jz4740_freq_info; ++ ++static struct cpufreq_driver cpufreq_jz4740_driver; ++ ++static void jz4740_freq_fill_table(struct cpufreq_policy *policy, ++ unsigned int pll_rate) ++{ ++ struct cpufreq_frequency_table *table = &jz4740_freq_info.table[0]; ++ int i; ++ ++#ifdef CONFIG_CPU_FREQ_STAT_DETAILS ++ /* for showing /sys/devices/system/cpu/cpuX/cpufreq/stats/ */ ++ static bool init = false; ++ if (init) ++ cpufreq_frequency_table_put_attr(policy->cpu); ++ else ++ init = true; ++#endif ++ ++ jz4740_freq_info.pll_rate = pll_rate; ++ ++ for (i = 0; i < ARRAY_SIZE(jz4740_freq_cpu_divs); i++) { ++ unsigned int freq = pll_rate / jz4740_freq_cpu_divs[i]; ++ if (freq < HCLK_MIN) break; ++ table[i].index = i; ++ table[i].frequency = freq; ++ } ++ table[i].index = i; ++ table[i].frequency = CPUFREQ_TABLE_END; ++ ++ policy->min = table[i - 1].frequency; ++ policy->max = table[0].frequency; ++ ++#ifdef CONFIG_CPU_FREQ_STAT_DETAILS ++ cpufreq_frequency_table_get_attr(table, policy->cpu); ++#endif ++} ++ ++static unsigned int jz4740_freq_get(unsigned int cpu) ++{ ++ return clk_get_rate(cclk) / 1000; ++} ++ ++static int jz4740_freq_verify(struct cpufreq_policy *policy) ++{ ++ unsigned int new_pll; ++ ++ cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq, ++ policy->cpuinfo.max_freq); ++ ++ new_pll = clk_round_rate(pll, policy->max * 1000) / 1000; ++ if (jz4740_freq_info.pll_rate != new_pll) ++ jz4740_freq_fill_table(policy, new_pll); ++ ++ return 0; ++} ++ ++static int jz4740_freq_target(struct cpufreq_policy *policy, ++ unsigned int target_freq, ++ unsigned int relation) ++{ ++ struct cpufreq_frequency_table *table = &jz4740_freq_info.table[0]; ++ struct cpufreq_freqs freqs; ++ unsigned int new_index = 0; ++ unsigned int old_pll = clk_get_rate(pll) / 1000; ++ unsigned int new_pll = jz4740_freq_info.pll_rate; ++ int ret = 0; ++ ++ if (cpufreq_frequency_table_target(policy, table, ++ target_freq, relation, &new_index)) ++ return -EINVAL; ++ freqs = (struct cpufreq_freqs) { ++ .old = jz4740_freq_get(policy->cpu), ++ .new = table[new_index].frequency, ++ .cpu = policy->cpu, ++ .flags = cpufreq_jz4740_driver.flags, ++ }; ++ if (freqs.new != freqs.old || new_pll != old_pll) { ++ unsigned int cdiv, hdiv, mdiv, pdiv; ++ cdiv = jz4740_freq_cpu_divs[new_index]; ++ hdiv = (cdiv == 3 || cdiv == 6) ? cdiv * 2 : cdiv * 3; ++ while (new_pll < HCLK_MIN * hdiv) ++ hdiv -= cdiv; ++ mdiv = hdiv; ++ if (new_pll > MCLK_MAX * mdiv) { ++ /* 4,4 performs better than 3,6 */ ++ if (new_pll > MCLK_MAX * 4) ++ mdiv *= 2; ++ else ++ hdiv = mdiv = cdiv * 4; ++ } ++ pdiv = mdiv; ++ dprintk(KERN_INFO "%s: cclk %p, setting from %d to %d, " ++ "dividers %d, %d, %d, %d\n", ++ __FUNCTION__, cclk, freqs.old, freqs.new, ++ cdiv, hdiv, mdiv, pdiv); ++ cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); ++ ret = clk_main_set_dividers(new_pll == old_pll, ++ cdiv, hdiv, mdiv, pdiv); ++ if (ret) { ++ dprintk(KERN_INFO "failed to set dividers\n"); ++ } else if (new_pll != old_pll) { ++ dprintk(KERN_INFO "%s: pll %p, setting from %d to %d\n", ++ __FUNCTION__, pll, old_pll, new_pll); ++ ret = clk_set_rate(pll, new_pll * 1000); ++ } ++ cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); ++ } ++ ++ return ret; ++} ++ ++static int jz4740_cpufreq_driver_init(struct cpufreq_policy *policy) ++{ ++ int ret; ++ ++ dprintk(KERN_INFO "Jz4740 cpufreq driver\n"); ++ ++ if (policy->cpu != 0) ++ return -EINVAL; ++ ++ pll = clk_get(NULL, "pll"); ++ if (IS_ERR(pll)) { ++ ret = PTR_ERR(pll); ++ goto err_exit; ++ } ++ ++ cclk = clk_get(NULL, "cclk"); ++ if (IS_ERR(cclk)) { ++ ret = PTR_ERR(cclk); ++ goto err_clk_put_pll; ++ } ++ ++ policy->cpuinfo.min_freq = HCLK_MIN; ++ policy->cpuinfo.max_freq = 500000; ++ policy->cpuinfo.transition_latency = 100000; /* in nanoseconds */ ++ policy->cur = jz4740_freq_get(policy->cpu); ++ policy->governor = CPUFREQ_DEFAULT_GOVERNOR; ++ /* min and max are set by jz4740_freq_fill_table() */ ++ ++ jz4740_freq_fill_table(policy, clk_get_rate(pll) / 1000 /* in kHz */); ++ ++ return 0; ++ ++err_clk_put_pll: ++ clk_put(pll); ++err_exit: ++ return ret; ++} ++ ++static struct cpufreq_driver cpufreq_jz4740_driver = { ++ .init = jz4740_cpufreq_driver_init, ++ .verify = jz4740_freq_verify, ++ .target = jz4740_freq_target, ++ .get = jz4740_freq_get, ++ .name = "jz4740", ++}; ++ ++static int __init jz4740_cpufreq_init(void) ++{ ++ return cpufreq_register_driver(&cpufreq_jz4740_driver); ++} ++ ++static void __exit jz4740_cpufreq_exit(void) ++{ ++ cpufreq_unregister_driver(&cpufreq_jz4740_driver); ++} ++ ++module_init(jz4740_cpufreq_init); ++module_exit(jz4740_cpufreq_exit); ++ ++MODULE_AUTHOR("Ulrich Hecht <ulrich.hecht@gmail.com>, " ++ "Maarten ter Huurne <maarten@treewalker.org>"); ++MODULE_DESCRIPTION("cpufreq driver for Jz4740"); ++MODULE_LICENSE("GPL"); +--- a/arch/mips/kernel/cpufreq/Kconfig ++++ b/arch/mips/kernel/cpufreq/Kconfig +@@ -8,7 +8,7 @@ config MIPS_EXTERNAL_TIMER + config MIPS_CPUFREQ + bool + default y +- depends on CPU_SUPPORTS_CPUFREQ && MIPS_EXTERNAL_TIMER ++ depends on CPU_SUPPORTS_CPUFREQ + + if MIPS_CPUFREQ + +@@ -24,6 +24,7 @@ config LOONGSON2_CPUFREQ + tristate "Loongson2 CPUFreq Driver" + select CPU_FREQ_TABLE + depends on MIPS_CPUFREQ ++ depends on MIPS_EXTERNAL_TIMER + help + This option adds a CPUFreq driver for loongson processors which + support software configurable cpu frequency. +@@ -34,6 +35,16 @@ config LOONGSON2_CPUFREQ + + If in doubt, say N. + ++config CPU_FREQ_JZ ++ tristate "CPUfreq driver for JZ CPUs" ++ select CPU_FREQ_TABLE ++ depends on MACH_JZ4740 ++ default n ++ help ++ This enables the CPUfreq driver for JZ CPUs. ++ ++ If in doubt, say N. ++ + endif # CPU_FREQ + + endmenu |