1/*
 2 * Copyright (c) 2009 Simtec Electronics
 3 *	http://armlinux.simtec.co.uk/
 4 *	Ben Dooks <ben@simtec.co.uk>
 5 *
 6 * S3C24XX CPU Frequency scaling - utils for S3C2410/S3C2440/S3C2442
 7 *
 8 * This program is free software; you can redistribute it and/or modify
 9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11*/
12
13#include <linux/kernel.h>
14#include <linux/errno.h>
15#include <linux/cpufreq.h>
16#include <linux/io.h>
17
18#include <mach/map.h>
19#include <mach/regs-clock.h>
20
21#include <plat/cpu-freq-core.h>
22
23#include "regs-mem.h"
24
25/**
26 * s3c2410_cpufreq_setrefresh - set SDRAM refresh value
27 * @cfg: The frequency configuration
28 *
29 * Set the SDRAM refresh value appropriately for the configured
30 * frequency.
31 */
32void s3c2410_cpufreq_setrefresh(struct s3c_cpufreq_config *cfg)
33{
34	struct s3c_cpufreq_board *board = cfg->board;
35	unsigned long refresh;
36	unsigned long refval;
37
38	/* Reduce both the refresh time (in ns) and the frequency (in MHz)
39	 * down to ensure that we do not overflow 32 bit numbers.
40	 *
41	 * This should work for HCLK up to 133MHz and refresh period up
42	 * to 30usec.
43	 */
44
45	refresh = (cfg->freq.hclk / 100) * (board->refresh / 10);
46	refresh = DIV_ROUND_UP(refresh, (1000 * 1000)); /* apply scale  */
47	refresh = (1 << 11) + 1 - refresh;
48
49	s3c_freq_dbg("%s: refresh value %lu\n", __func__, refresh);
50
51	refval = __raw_readl(S3C2410_REFRESH);
52	refval &= ~((1 << 12) - 1);
53	refval |= refresh;
54	__raw_writel(refval, S3C2410_REFRESH);
55}
56
57/**
58 * s3c2410_set_fvco - set the PLL value
59 * @cfg: The frequency configuration
60 */
61void s3c2410_set_fvco(struct s3c_cpufreq_config *cfg)
62{
63	__raw_writel(cfg->pll.driver_data, S3C2410_MPLLCON);
64}