/* * Copyright (c) 2010-2011 Samsung Electronics Co., Ltd. * http://www.samsung.com * * EXYNOS4210 - CPU frequency scaling support * * 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/module.h> #include <linux/kernel.h> #include <linux/err.h> #include <linux/clk.h> #include <linux/io.h> #include <linux/slab.h> #include <linux/cpufreq.h> #include <linux/of.h> #include <linux/of_address.h> #include "exynos-cpufreq.h" static struct clk *cpu_clk; static struct clk *moutcore; static struct clk *mout_mpll; static struct clk *mout_apll; static struct exynos_dvfs_info *cpufreq; static unsigned int exynos4210_volt_table[] = { 1250000, 1150000, 1050000, 975000, 950000, }; static struct cpufreq_frequency_table exynos4210_freq_table[] = { {0, L0, 1200 * 1000}, {0, L1, 1000 * 1000}, {0, L2, 800 * 1000}, {0, L3, 500 * 1000}, {0, L4, 200 * 1000}, {0, 0, CPUFREQ_TABLE_END}, }; static struct apll_freq apll_freq_4210[] = { /* * values: * freq * clock divider for CORE, COREM0, COREM1, PERIPH, ATB, PCLK_DBG, APLL, RESERVED * clock divider for COPY, HPM, RESERVED * PLL M, P, S */ APLL_FREQ(1200, 0, 3, 7, 3, 4, 1, 7, 0, 5, 0, 0, 150, 3, 1), APLL_FREQ(1000, 0, 3, 7, 3, 4, 1, 7, 0, 4, 0, 0, 250, 6, 1), APLL_FREQ(800, 0, 3, 7, 3, 3, 1, 7, 0, 3, 0, 0, 200, 6, 1), APLL_FREQ(500, 0, 3, 7, 3, 3, 1, 7, 0, 3, 0, 0, 250, 6, 2), APLL_FREQ(200, 0, 1, 3, 1, 3, 1, 0, 0, 3, 0, 0, 200, 6, 3), }; static void exynos4210_set_clkdiv(unsigned int div_index) { unsigned int tmp; /* Change Divider - CPU0 */ tmp = apll_freq_4210[div_index].clk_div_cpu0; __raw_writel(tmp, cpufreq->cmu_regs + EXYNOS4_CLKDIV_CPU); do { tmp = __raw_readl(cpufreq->cmu_regs + EXYNOS4_CLKDIV_STATCPU); } while (tmp & 0x1111111); /* Change Divider - CPU1 */ tmp = apll_freq_4210[div_index].clk_div_cpu1; __raw_writel(tmp, cpufreq->cmu_regs + EXYNOS4_CLKDIV_CPU1); do { tmp = __raw_readl(cpufreq->cmu_regs + EXYNOS4_CLKDIV_STATCPU1); } while (tmp & 0x11); } static void exynos4210_set_apll(unsigned int index) { unsigned int tmp, freq = apll_freq_4210[index].freq; /* MUX_CORE_SEL = MPLL, ARMCLK uses MPLL for lock time */ clk_set_parent(moutcore, mout_mpll); do { tmp = (__raw_readl(cpufreq->cmu_regs + EXYNOS4_CLKMUX_STATCPU) >> EXYNOS4_CLKSRC_CPU_MUXCORE_SHIFT); tmp &= 0x7; } while (tmp != 0x2); clk_set_rate(mout_apll, freq * 1000); /* MUX_CORE_SEL = APLL */ clk_set_parent(moutcore, mout_apll); do { tmp = __raw_readl(cpufreq->cmu_regs + EXYNOS4_CLKMUX_STATCPU); tmp &= EXYNOS4_CLKMUX_STATCPU_MUXCORE_MASK; } while (tmp != (0x1 << EXYNOS4_CLKSRC_CPU_MUXCORE_SHIFT)); } static void exynos4210_set_frequency(unsigned int old_index, unsigned int new_index) { if (old_index > new_index) { exynos4210_set_clkdiv(new_index); exynos4210_set_apll(new_index); } else if (old_index < new_index) { exynos4210_set_apll(new_index); exynos4210_set_clkdiv(new_index); } } int exynos4210_cpufreq_init(struct exynos_dvfs_info *info) { struct device_node *np; unsigned long rate; /* * HACK: This is a temporary workaround to get access to clock * controller registers directly and remove static mappings and * dependencies on platform headers. It is necessary to enable * Exynos multi-platform support and will be removed together with * this whole driver as soon as Exynos gets migrated to use * cpufreq-dt driver. */ np = of_find_compatible_node(NULL, NULL, "samsung,exynos4210-clock"); if (!np) { pr_err("%s: failed to find clock controller DT node\n", __func__); return -ENODEV; } info->cmu_regs = of_iomap(np, 0); if (!info->cmu_regs) { pr_err("%s: failed to map CMU registers\n", __func__); return -EFAULT; } cpu_clk = clk_get(NULL, "armclk"); if (IS_ERR(cpu_clk)) return PTR_ERR(cpu_clk); moutcore = clk_get(NULL, "moutcore"); if (IS_ERR(moutcore)) goto err_moutcore; mout_mpll = clk_get(NULL, "mout_mpll"); if (IS_ERR(mout_mpll)) goto err_mout_mpll; rate = clk_get_rate(mout_mpll) / 1000; mout_apll = clk_get(NULL, "mout_apll"); if (IS_ERR(mout_apll)) goto err_mout_apll; info->mpll_freq_khz = rate; /* 800Mhz */ info->pll_safe_idx = L2; info->cpu_clk = cpu_clk; info->volt_table = exynos4210_volt_table; info->freq_table = exynos4210_freq_table; info->set_freq = exynos4210_set_frequency; cpufreq = info; return 0; err_mout_apll: clk_put(mout_mpll); err_mout_mpll: clk_put(moutcore); err_moutcore: clk_put(cpu_clk); pr_debug("%s: failed initialization\n", __func__); return -EINVAL; }