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![Tomasz Figa](/assets/img/avatar_default.png)
Currently Exynos cpufreq drivers rely on globally mapped clock controller registers to configure frequency of CPU cores. This is obviously wrong and will be removed in near future, but to enable support for multi-platform builds without introducing a regression it needs to be worked around. This patch hacks the code to look for clock controller node in device tree and map its registers using of_iomap(), instead of relying on global mapping, so dependencies on platform headers are removed and the driver can compile again with multiplatform support. Signed-off-by: Tomasz Figa <t.figa@samsung.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
184 lines
4.6 KiB
C
184 lines
4.6 KiB
C
/*
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* Copyright (c) 2010-2011 Samsung Electronics Co., Ltd.
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* http://www.samsung.com
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*
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* EXYNOS4210 - CPU frequency scaling 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 version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/err.h>
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#include <linux/clk.h>
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#include <linux/io.h>
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#include <linux/slab.h>
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#include <linux/cpufreq.h>
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#include <linux/of.h>
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#include <linux/of_address.h>
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#include "exynos-cpufreq.h"
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static struct clk *cpu_clk;
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static struct clk *moutcore;
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static struct clk *mout_mpll;
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static struct clk *mout_apll;
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static struct exynos_dvfs_info *cpufreq;
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static unsigned int exynos4210_volt_table[] = {
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1250000, 1150000, 1050000, 975000, 950000,
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};
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static struct cpufreq_frequency_table exynos4210_freq_table[] = {
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{0, L0, 1200 * 1000},
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{0, L1, 1000 * 1000},
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{0, L2, 800 * 1000},
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{0, L3, 500 * 1000},
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{0, L4, 200 * 1000},
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{0, 0, CPUFREQ_TABLE_END},
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};
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static struct apll_freq apll_freq_4210[] = {
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/*
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* values:
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* freq
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* clock divider for CORE, COREM0, COREM1, PERIPH, ATB, PCLK_DBG, APLL, RESERVED
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* clock divider for COPY, HPM, RESERVED
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* PLL M, P, S
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*/
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APLL_FREQ(1200, 0, 3, 7, 3, 4, 1, 7, 0, 5, 0, 0, 150, 3, 1),
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APLL_FREQ(1000, 0, 3, 7, 3, 4, 1, 7, 0, 4, 0, 0, 250, 6, 1),
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APLL_FREQ(800, 0, 3, 7, 3, 3, 1, 7, 0, 3, 0, 0, 200, 6, 1),
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APLL_FREQ(500, 0, 3, 7, 3, 3, 1, 7, 0, 3, 0, 0, 250, 6, 2),
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APLL_FREQ(200, 0, 1, 3, 1, 3, 1, 0, 0, 3, 0, 0, 200, 6, 3),
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};
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static void exynos4210_set_clkdiv(unsigned int div_index)
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{
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unsigned int tmp;
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/* Change Divider - CPU0 */
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tmp = apll_freq_4210[div_index].clk_div_cpu0;
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__raw_writel(tmp, cpufreq->cmu_regs + EXYNOS4_CLKDIV_CPU);
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do {
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tmp = __raw_readl(cpufreq->cmu_regs + EXYNOS4_CLKDIV_STATCPU);
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} while (tmp & 0x1111111);
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/* Change Divider - CPU1 */
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tmp = apll_freq_4210[div_index].clk_div_cpu1;
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__raw_writel(tmp, cpufreq->cmu_regs + EXYNOS4_CLKDIV_CPU1);
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do {
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tmp = __raw_readl(cpufreq->cmu_regs + EXYNOS4_CLKDIV_STATCPU1);
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} while (tmp & 0x11);
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}
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static void exynos4210_set_apll(unsigned int index)
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{
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unsigned int tmp, freq = apll_freq_4210[index].freq;
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/* MUX_CORE_SEL = MPLL, ARMCLK uses MPLL for lock time */
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clk_set_parent(moutcore, mout_mpll);
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do {
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tmp = (__raw_readl(cpufreq->cmu_regs + EXYNOS4_CLKMUX_STATCPU)
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>> EXYNOS4_CLKSRC_CPU_MUXCORE_SHIFT);
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tmp &= 0x7;
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} while (tmp != 0x2);
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clk_set_rate(mout_apll, freq * 1000);
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/* MUX_CORE_SEL = APLL */
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clk_set_parent(moutcore, mout_apll);
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do {
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tmp = __raw_readl(cpufreq->cmu_regs + EXYNOS4_CLKMUX_STATCPU);
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tmp &= EXYNOS4_CLKMUX_STATCPU_MUXCORE_MASK;
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} while (tmp != (0x1 << EXYNOS4_CLKSRC_CPU_MUXCORE_SHIFT));
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}
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static void exynos4210_set_frequency(unsigned int old_index,
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unsigned int new_index)
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{
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if (old_index > new_index) {
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exynos4210_set_clkdiv(new_index);
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exynos4210_set_apll(new_index);
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} else if (old_index < new_index) {
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exynos4210_set_apll(new_index);
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exynos4210_set_clkdiv(new_index);
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}
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}
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int exynos4210_cpufreq_init(struct exynos_dvfs_info *info)
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{
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struct device_node *np;
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unsigned long rate;
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/*
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* HACK: This is a temporary workaround to get access to clock
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* controller registers directly and remove static mappings and
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* dependencies on platform headers. It is necessary to enable
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* Exynos multi-platform support and will be removed together with
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* this whole driver as soon as Exynos gets migrated to use
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* cpufreq-cpu0 driver.
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*/
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np = of_find_compatible_node(NULL, NULL, "samsung,exynos4210-clock");
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if (!np) {
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pr_err("%s: failed to find clock controller DT node\n",
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__func__);
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return -ENODEV;
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}
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info->cmu_regs = of_iomap(np, 0);
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if (!info->cmu_regs) {
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pr_err("%s: failed to map CMU registers\n", __func__);
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return -EFAULT;
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}
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cpu_clk = clk_get(NULL, "armclk");
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if (IS_ERR(cpu_clk))
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return PTR_ERR(cpu_clk);
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moutcore = clk_get(NULL, "moutcore");
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if (IS_ERR(moutcore))
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goto err_moutcore;
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mout_mpll = clk_get(NULL, "mout_mpll");
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if (IS_ERR(mout_mpll))
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goto err_mout_mpll;
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rate = clk_get_rate(mout_mpll) / 1000;
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mout_apll = clk_get(NULL, "mout_apll");
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if (IS_ERR(mout_apll))
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goto err_mout_apll;
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info->mpll_freq_khz = rate;
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/* 800Mhz */
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info->pll_safe_idx = L2;
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info->cpu_clk = cpu_clk;
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info->volt_table = exynos4210_volt_table;
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info->freq_table = exynos4210_freq_table;
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info->set_freq = exynos4210_set_frequency;
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cpufreq = info;
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return 0;
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err_mout_apll:
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clk_put(mout_mpll);
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err_mout_mpll:
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clk_put(moutcore);
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err_moutcore:
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clk_put(cpu_clk);
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pr_debug("%s: failed initialization\n", __func__);
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return -EINVAL;
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}
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