99c13853ff
Patch from Ben Dooks Split the s3c2410 specific clocks from the core clock code, as part of the work to support more of the Samsung line of SoCs. The patch does not use the sysdev mechanism as the clocks are needed for the timer init, which is very early in the kernel init sequence. Signed-off-by: Ben Dooks <ben-linux@fluff.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
172 lines
4.2 KiB
C
172 lines
4.2 KiB
C
/* linux/arch/arm/mach-s3c2410/s3c2442-clock.c
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*
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* Copyright (c) 2004-2005 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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* S3C2442 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/mutex.h>
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#include <linux/clk.h>
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#include <asm/hardware.h>
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#include <asm/atomic.h>
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#include <asm/irq.h>
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#include <asm/io.h>
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#include <asm/arch/regs-clock.h>
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#include "clock.h"
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#include "cpu.h"
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/* S3C2442 extended clock support */
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static unsigned long s3c2442_camif_upll_round(struct clk *clk,
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unsigned long rate)
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{
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unsigned long parent_rate = clk_get_rate(clk->parent);
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int div;
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if (rate > parent_rate)
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return parent_rate;
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div = parent_rate / rate;
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if (div == 3)
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return parent_rate / 3;
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/* note, we remove the +/- 1 calculations for the divisor */
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div /= 2;
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if (div < 1)
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div = 1;
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else if (div > 16)
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div = 16;
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return parent_rate / (div * 2);
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}
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static int s3c2442_camif_upll_setrate(struct clk *clk, unsigned long rate)
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{
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unsigned long parent_rate = clk_get_rate(clk->parent);
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unsigned long camdivn = __raw_readl(S3C2440_CAMDIVN);
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rate = s3c2442_camif_upll_round(clk, rate);
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camdivn &= ~S3C2442_CAMDIVN_CAMCLK_DIV3;
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if (rate == parent_rate) {
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camdivn &= ~S3C2440_CAMDIVN_CAMCLK_SEL;
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} else if ((parent_rate / rate) == 3) {
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camdivn |= S3C2440_CAMDIVN_CAMCLK_SEL;
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camdivn |= S3C2442_CAMDIVN_CAMCLK_DIV3;
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} else {
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camdivn &= ~S3C2440_CAMDIVN_CAMCLK_MASK;
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camdivn |= S3C2440_CAMDIVN_CAMCLK_SEL;
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camdivn |= (((parent_rate / rate) / 2) - 1);
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}
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__raw_writel(camdivn, S3C2440_CAMDIVN);
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return 0;
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}
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/* Extra S3C2442 clocks */
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static struct clk s3c2442_clk_cam = {
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.name = "camif",
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.id = -1,
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.enable = s3c2410_clkcon_enable,
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.ctrlbit = S3C2440_CLKCON_CAMERA,
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};
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static struct clk s3c2442_clk_cam_upll = {
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.name = "camif-upll",
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.id = -1,
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.set_rate = s3c2442_camif_upll_setrate,
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.round_rate = s3c2442_camif_upll_round,
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};
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static int s3c2442_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 *clk_h;
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struct clk *clk_p;
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struct clk *clk_upll;
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printk("S3C2442: Clock Support, DVS %s\n",
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(camdivn & S3C2440_CAMDIVN_DVSEN) ? "on" : "off");
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clk_p = clk_get(NULL, "pclk");
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clk_h = clk_get(NULL, "hclk");
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clk_upll = clk_get(NULL, "upll");
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if (IS_ERR(clk_p) || IS_ERR(clk_h) || IS_ERR(clk_upll)) {
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printk(KERN_ERR "S3C2442: Failed to get parent clocks\n");
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return -EINVAL;
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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(clk_upll) > (94 * MHZ)) {
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clk_usb_bus.rate = clk_get_rate(clk_upll) / 2;
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mutex_lock(&clocks_mutex);
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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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mutex_unlock(&clocks_mutex);
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}
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s3c2442_clk_cam.parent = clk_h;
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s3c2442_clk_cam_upll.parent = clk_upll;
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s3c24xx_register_clock(&s3c2442_clk_cam);
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s3c24xx_register_clock(&s3c2442_clk_cam_upll);
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clk_disable(&s3c2442_clk_cam);
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return 0;
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}
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static struct sysdev_driver s3c2442_clk_driver = {
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.add = s3c2442_clk_add,
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};
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static __init 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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