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author | Linus Torvalds <torvalds@linux-foundation.org> | 2013-02-21 23:58:40 +0100 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-02-21 23:58:40 +0100 |
commit | b274776c54c320763bc12eb035c0e244f76ccb43 (patch) | |
tree | c75b70d0824a7ae029229b19d61884039abf2127 /arch/arm/mach-s3c24xx/cpufreq-s3c2412.c | |
parent | Merge tag 'fixes-non-critical' of git://git.kernel.org/pub/scm/linux/kernel/g... (diff) | |
parent | Merge tag 'cleanup_for_v3.9_round3' of git://git.infradead.org/users/jcooper/... (diff) | |
download | linux-b274776c54c320763bc12eb035c0e244f76ccb43.tar.xz linux-b274776c54c320763bc12eb035c0e244f76ccb43.zip |
Merge tag 'cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM SoC cleanups from Arnd Bergmann:
"A large number of cleanups, all over the platforms. This is dominated
largely by the Samsung platforms (s3c, s5p, exynos) and a few of the
others moving code out of arch/arm into more appropriate subsystems.
The clocksource and irqchip drivers are now abstracted to the point
where platforms that are already cleaned up do not need to even
specify the driver they use, it can all get configured from the device
tree as we do for normal device drivers. The clocksource changes
basically touch every single platform in the process.
We further clean up the use of platform specific header files here,
with the goal of turning more of the platforms over to being
"multiplatform" enabled, which implies that they cannot expose their
headers to architecture independent code any more.
It is expected that no functional changes are part of the cleanup.
The overall reduction in total code lines is mostly the result of
removing broken and obsolete code."
* tag 'cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (133 commits)
ARM: mvebu: correct gated clock documentation
ARM: kirkwood: add missing include for nsa310
ARM: exynos: move exynos4210-combiner to drivers/irqchip
mfd: db8500-prcmu: update resource passing
drivers/db8500-cpufreq: delete dangling include
ARM: at91: remove NEOCORE 926 board
sunxi: Cleanup the reset code and add meaningful registers defines
ARM: S3C24XX: header mach/regs-mem.h local
ARM: S3C24XX: header mach/regs-power.h local
ARM: S3C24XX: header mach/regs-s3c2412-mem.h local
ARM: S3C24XX: Remove plat-s3c24xx directory in arch/arm/
ARM: S3C24XX: transform s3c2443 subirqs into new structure
ARM: S3C24XX: modify s3c2443 irq init to initialize all irqs
ARM: S3C24XX: move s3c2443 irq code to irq.c
ARM: S3C24XX: transform s3c2416 irqs into new structure
ARM: S3C24XX: modify s3c2416 irq init to initialize all irqs
ARM: S3C24XX: move s3c2416 irq init to common irq code
ARM: S3C24XX: Modify s3c_irq_wake to use the hwirq property
ARM: S3C24XX: Move irq syscore-ops to irq-pm
clocksource: always define CLOCKSOURCE_OF_DECLARE
...
Diffstat (limited to 'arch/arm/mach-s3c24xx/cpufreq-s3c2412.c')
-rw-r--r-- | arch/arm/mach-s3c24xx/cpufreq-s3c2412.c | 258 |
1 files changed, 258 insertions, 0 deletions
diff --git a/arch/arm/mach-s3c24xx/cpufreq-s3c2412.c b/arch/arm/mach-s3c24xx/cpufreq-s3c2412.c new file mode 100644 index 000000000000..8bf0f3a77476 --- /dev/null +++ b/arch/arm/mach-s3c24xx/cpufreq-s3c2412.c @@ -0,0 +1,258 @@ +/* + * Copyright 2008 Simtec Electronics + * http://armlinux.simtec.co.uk/ + * Ben Dooks <ben@simtec.co.uk> + * + * S3C2412 CPU Frequency scalling + * + * 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/init.h> +#include <linux/module.h> +#include <linux/interrupt.h> +#include <linux/ioport.h> +#include <linux/cpufreq.h> +#include <linux/device.h> +#include <linux/delay.h> +#include <linux/clk.h> +#include <linux/err.h> +#include <linux/io.h> + +#include <asm/mach/arch.h> +#include <asm/mach/map.h> + +#include <mach/regs-clock.h> + +#include <plat/cpu.h> +#include <plat/clock.h> +#include <plat/cpu-freq-core.h> + +#include "s3c2412.h" + +/* our clock resources. */ +static struct clk *xtal; +static struct clk *fclk; +static struct clk *hclk; +static struct clk *armclk; + +/* HDIV: 1, 2, 3, 4, 6, 8 */ + +static int s3c2412_cpufreq_calcdivs(struct s3c_cpufreq_config *cfg) +{ + unsigned int hdiv, pdiv, armdiv, dvs; + unsigned long hclk, fclk, armclk, armdiv_clk; + unsigned long hclk_max; + + fclk = cfg->freq.fclk; + armclk = cfg->freq.armclk; + hclk_max = cfg->max.hclk; + + /* We can't run hclk above armclk as at the best we have to + * have armclk and hclk in dvs mode. */ + + if (hclk_max > armclk) + hclk_max = armclk; + + s3c_freq_dbg("%s: fclk=%lu, armclk=%lu, hclk_max=%lu\n", + __func__, fclk, armclk, hclk_max); + s3c_freq_dbg("%s: want f=%lu, arm=%lu, h=%lu, p=%lu\n", + __func__, cfg->freq.fclk, cfg->freq.armclk, + cfg->freq.hclk, cfg->freq.pclk); + + armdiv = fclk / armclk; + + if (armdiv < 1) + armdiv = 1; + if (armdiv > 2) + armdiv = 2; + + cfg->divs.arm_divisor = armdiv; + armdiv_clk = fclk / armdiv; + + hdiv = armdiv_clk / hclk_max; + if (hdiv < 1) + hdiv = 1; + + cfg->freq.hclk = hclk = armdiv_clk / hdiv; + + /* set dvs depending on whether we reached armclk or not. */ + cfg->divs.dvs = dvs = armclk < armdiv_clk; + + /* update the actual armclk we achieved. */ + cfg->freq.armclk = dvs ? hclk : armdiv_clk; + + s3c_freq_dbg("%s: armclk %lu, hclk %lu, armdiv %d, hdiv %d, dvs %d\n", + __func__, armclk, hclk, armdiv, hdiv, cfg->divs.dvs); + + if (hdiv > 4) + goto invalid; + + pdiv = (hclk > cfg->max.pclk) ? 2 : 1; + + if ((hclk / pdiv) > cfg->max.pclk) + pdiv++; + + cfg->freq.pclk = hclk / pdiv; + + s3c_freq_dbg("%s: pdiv %d\n", __func__, pdiv); + + if (pdiv > 2) + goto invalid; + + pdiv *= hdiv; + + /* store the result, and then return */ + + cfg->divs.h_divisor = hdiv * armdiv; + cfg->divs.p_divisor = pdiv * armdiv; + + return 0; + +invalid: + return -EINVAL; +} + +static void s3c2412_cpufreq_setdivs(struct s3c_cpufreq_config *cfg) +{ + unsigned long clkdiv; + unsigned long olddiv; + + olddiv = clkdiv = __raw_readl(S3C2410_CLKDIVN); + + /* clear off current clock info */ + + clkdiv &= ~S3C2412_CLKDIVN_ARMDIVN; + clkdiv &= ~S3C2412_CLKDIVN_HDIVN_MASK; + clkdiv &= ~S3C2412_CLKDIVN_PDIVN; + + if (cfg->divs.arm_divisor == 2) + clkdiv |= S3C2412_CLKDIVN_ARMDIVN; + + clkdiv |= ((cfg->divs.h_divisor / cfg->divs.arm_divisor) - 1); + + if (cfg->divs.p_divisor != cfg->divs.h_divisor) + clkdiv |= S3C2412_CLKDIVN_PDIVN; + + s3c_freq_dbg("%s: div %08lx => %08lx\n", __func__, olddiv, clkdiv); + __raw_writel(clkdiv, S3C2410_CLKDIVN); + + clk_set_parent(armclk, cfg->divs.dvs ? hclk : fclk); +} + +static void s3c2412_cpufreq_setrefresh(struct s3c_cpufreq_config *cfg) +{ + struct s3c_cpufreq_board *board = cfg->board; + unsigned long refresh; + + s3c_freq_dbg("%s: refresh %u ns, hclk %lu\n", __func__, + board->refresh, cfg->freq.hclk); + + /* Reduce both the refresh time (in ns) and the frequency (in MHz) + * by 10 each to ensure that we do not overflow 32 bit numbers. This + * should work for HCLK up to 133MHz and refresh period up to 30usec. + */ + + refresh = (board->refresh / 10); + refresh *= (cfg->freq.hclk / 100); + refresh /= (1 * 1000 * 1000); /* 10^6 */ + + s3c_freq_dbg("%s: setting refresh 0x%08lx\n", __func__, refresh); + __raw_writel(refresh, S3C2412_REFRESH); +} + +/* set the default cpu frequency information, based on an 200MHz part + * as we have no other way of detecting the speed rating in software. + */ + +static struct s3c_cpufreq_info s3c2412_cpufreq_info = { + .max = { + .fclk = 200000000, + .hclk = 100000000, + .pclk = 50000000, + }, + + .latency = 5000000, /* 5ms */ + + .locktime_m = 150, + .locktime_u = 150, + .locktime_bits = 16, + + .name = "s3c2412", + .set_refresh = s3c2412_cpufreq_setrefresh, + .set_divs = s3c2412_cpufreq_setdivs, + .calc_divs = s3c2412_cpufreq_calcdivs, + + .calc_iotiming = s3c2412_iotiming_calc, + .set_iotiming = s3c2412_iotiming_set, + .get_iotiming = s3c2412_iotiming_get, + + .resume_clocks = s3c2412_setup_clocks, + + .debug_io_show = s3c_cpufreq_debugfs_call(s3c2412_iotiming_debugfs), +}; + +static int s3c2412_cpufreq_add(struct device *dev, + struct subsys_interface *sif) +{ + unsigned long fclk_rate; + + hclk = clk_get(NULL, "hclk"); + if (IS_ERR(hclk)) { + printk(KERN_ERR "%s: cannot find hclk clock\n", __func__); + return -ENOENT; + } + + fclk = clk_get(NULL, "fclk"); + if (IS_ERR(fclk)) { + printk(KERN_ERR "%s: cannot find fclk clock\n", __func__); + goto err_fclk; + } + + fclk_rate = clk_get_rate(fclk); + if (fclk_rate > 200000000) { + printk(KERN_INFO + "%s: fclk %ld MHz, assuming 266MHz capable part\n", + __func__, fclk_rate / 1000000); + s3c2412_cpufreq_info.max.fclk = 266000000; + s3c2412_cpufreq_info.max.hclk = 133000000; + s3c2412_cpufreq_info.max.pclk = 66000000; + } + + armclk = clk_get(NULL, "armclk"); + if (IS_ERR(armclk)) { + printk(KERN_ERR "%s: cannot find arm clock\n", __func__); + goto err_armclk; + } + + xtal = clk_get(NULL, "xtal"); + if (IS_ERR(xtal)) { + printk(KERN_ERR "%s: cannot find xtal clock\n", __func__); + goto err_xtal; + } + + return s3c_cpufreq_register(&s3c2412_cpufreq_info); + +err_xtal: + clk_put(armclk); +err_armclk: + clk_put(fclk); +err_fclk: + clk_put(hclk); + + return -ENOENT; +} + +static struct subsys_interface s3c2412_cpufreq_interface = { + .name = "s3c2412_cpufreq", + .subsys = &s3c2412_subsys, + .add_dev = s3c2412_cpufreq_add, +}; + +static int s3c2412_cpufreq_init(void) +{ + return subsys_interface_register(&s3c2412_cpufreq_interface); +} +arch_initcall(s3c2412_cpufreq_init); |