projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
| 84b21701 KK |
1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | // | |
| 3 | // Copyright (c) 2009 Simtec Electronics | |
| 4 | // http://armlinux.simtec.co.uk/ | |
| 5 | // Ben Dooks <ben@simtec.co.uk> | |
| 6 | // | |
| 7 | // S3C24XX CPU Frequency scaling - utils for S3C2410/S3C2440/S3C2442 | |
| a24c091d BD |
8 | |
| 9 | #include <linux/kernel.h> | |
| 10 | #include <linux/errno.h> | |
| 11 | #include <linux/cpufreq.h> | |
| 12 | #include <linux/io.h> | |
| d8b53257 | 13 | #include <linux/clk.h> |
| a24c091d BD |
14 | |
| 15 | #include <mach/map.h> | |
| a24c091d BD |
16 | #include <mach/regs-clock.h> |
| 17 | ||
| 18 | #include <plat/cpu-freq-core.h> | |
| 19 | ||
| 37c3adca KK |
20 | #include "regs-mem.h" |
| 21 | ||
| a24c091d BD |
22 | /** |
| 23 | * s3c2410_cpufreq_setrefresh - set SDRAM refresh value | |
| 24 | * @cfg: The frequency configuration | |
| 25 | * | |
| 26 | * Set the SDRAM refresh value appropriately for the configured | |
| 27 | * frequency. | |
| 28 | */ | |
| 29 | void s3c2410_cpufreq_setrefresh(struct s3c_cpufreq_config *cfg) | |
| 30 | { | |
| 31 | struct s3c_cpufreq_board *board = cfg->board; | |
| 32 | unsigned long refresh; | |
| 33 | unsigned long refval; | |
| 34 | ||
| 35 | /* Reduce both the refresh time (in ns) and the frequency (in MHz) | |
| 36 | * down to ensure that we do not overflow 32 bit numbers. | |
| 37 | * | |
| 38 | * This should work for HCLK up to 133MHz and refresh period up | |
| 39 | * to 30usec. | |
| 40 | */ | |
| 41 | ||
| 42 | refresh = (cfg->freq.hclk / 100) * (board->refresh / 10); | |
| 43 | refresh = DIV_ROUND_UP(refresh, (1000 * 1000)); /* apply scale */ | |
| 44 | refresh = (1 << 11) + 1 - refresh; | |
| 45 | ||
| 46 | s3c_freq_dbg("%s: refresh value %lu\n", __func__, refresh); | |
| 47 | ||
| 48 | refval = __raw_readl(S3C2410_REFRESH); | |
| 49 | refval &= ~((1 << 12) - 1); | |
| 50 | refval |= refresh; | |
| 51 | __raw_writel(refval, S3C2410_REFRESH); | |
| 52 | } | |
| 53 | ||
| 54 | /** | |
| 55 | * s3c2410_set_fvco - set the PLL value | |
| 56 | * @cfg: The frequency configuration | |
| 57 | */ | |
| 58 | void s3c2410_set_fvco(struct s3c_cpufreq_config *cfg) | |
| 59 | { | |
| d8b53257 HS |
60 | if (!IS_ERR(cfg->mpll)) |
| 61 | clk_set_rate(cfg->mpll, cfg->pll.frequency); | |
| a24c091d | 62 | } |