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c3391e36d6
We cannot sleep if we have cpufreq pm enabled during some of the clock operations, so change to use a spinlock to protect the clock system. Signed-off-by: Ben Dooks <ben-linux@fluff.org>
137 lines
3.3 KiB
C
137 lines
3.3 KiB
C
/* linux/arch/arm/plat-s3c24xx/s3c24xx-clock.c
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*
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* Copyright (c) 2004-2005,2008 Simtec Electronics
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* http://armlinux.simtec.co.uk/
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* Ben Dooks <ben@simtec.co.uk>
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*
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* S3C2440/S3C2442 Common clock support
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/list.h>
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#include <linux/errno.h>
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#include <linux/err.h>
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#include <linux/device.h>
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#include <linux/sysdev.h>
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#include <linux/interrupt.h>
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#include <linux/ioport.h>
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#include <linux/clk.h>
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#include <linux/io.h>
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#include <mach/hardware.h>
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#include <asm/atomic.h>
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#include <asm/irq.h>
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#include <mach/regs-clock.h>
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#include <plat/clock.h>
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#include <plat/cpu.h>
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static int s3c2440_setparent_armclk(struct clk *clk, struct clk *parent)
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{
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unsigned long camdivn;
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unsigned long dvs;
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if (parent == &clk_f)
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dvs = 0;
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else if (parent == &clk_h)
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dvs = S3C2440_CAMDIVN_DVSEN;
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else
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return -EINVAL;
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clk->parent = parent;
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camdivn = __raw_readl(S3C2440_CAMDIVN);
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camdivn &= ~S3C2440_CAMDIVN_DVSEN;
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camdivn |= dvs;
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__raw_writel(camdivn, S3C2440_CAMDIVN);
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return 0;
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}
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static struct clk clk_arm = {
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.name = "armclk",
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.id = -1,
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.set_parent = s3c2440_setparent_armclk,
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};
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static int s3c244x_clk_add(struct sys_device *sysdev)
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{
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unsigned long camdivn = __raw_readl(S3C2440_CAMDIVN);
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unsigned long clkdivn;
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struct clk *clock_upll;
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int ret;
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printk("S3C244X: Clock Support, DVS %s\n",
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(camdivn & S3C2440_CAMDIVN_DVSEN) ? "on" : "off");
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clk_arm.parent = (camdivn & S3C2440_CAMDIVN_DVSEN) ? &clk_h : &clk_f;
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ret = s3c24xx_register_clock(&clk_arm);
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if (ret < 0) {
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printk(KERN_ERR "S3C24XX: Failed to add armclk (%d)\n", ret);
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return ret;
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}
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clock_upll = clk_get(NULL, "upll");
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if (IS_ERR(clock_upll)) {
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printk(KERN_ERR "S3C244X: Failed to get upll clock\n");
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return -ENOENT;
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}
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/* check rate of UPLL, and if it is near 96MHz, then change
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* to using half the UPLL rate for the system */
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if (clk_get_rate(clock_upll) > (94 * MHZ)) {
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clk_usb_bus.rate = clk_get_rate(clock_upll) / 2;
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spin_lock(&clocks_lock);
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clkdivn = __raw_readl(S3C2410_CLKDIVN);
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clkdivn |= S3C2440_CLKDIVN_UCLK;
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__raw_writel(clkdivn, S3C2410_CLKDIVN);
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spin_unlock(&clocks_lock);
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}
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return 0;
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}
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static struct sysdev_driver s3c2440_clk_driver = {
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.add = s3c244x_clk_add,
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};
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static int s3c2440_clk_init(void)
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{
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return sysdev_driver_register(&s3c2440_sysclass, &s3c2440_clk_driver);
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}
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arch_initcall(s3c2440_clk_init);
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static struct sysdev_driver s3c2442_clk_driver = {
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.add = s3c244x_clk_add,
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};
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static int s3c2442_clk_init(void)
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{
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return sysdev_driver_register(&s3c2442_sysclass, &s3c2442_clk_driver);
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}
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arch_initcall(s3c2442_clk_init);
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