Re: [PATCH 4/6] cpufreq: exynos: remove Exynos4210 specific cpufreq driver support

Lukasz Majewski
2014-01-10T10:20:55Z

Hi Thomas,

> The Exynos4210 specific cpufreq driver performs read/write operations
> of clock controller registers bypassing the Exynos common clock
> framework driver. This could lead to potential issues if CCF and
> cpufreq driver modify the clock registers independently of each other.
> In addition to this, the generic cpufreq-cpu0 driver is sufficient
> for Exynos4210 based platforms since this SoC uses a single clock
> and voltage line for both the ARM cores. So remove the support for
> Exynos4210 specific cpufreq driver and use cpufreq-cpu0 driver
> for Exynos4210 platforms
>
> Signed-off-by: Thomas Abraham <thomas.ab@samsung.com>
> ---
> drivers/cpufreq/Kconfig.arm | 11 ---
> drivers/cpufreq/Makefile | 1 -
> drivers/cpufreq/exynos-cpufreq.c | 4 +-
> drivers/cpufreq/exynos-cpufreq.h | 8 --
> drivers/cpufreq/exynos4210-cpufreq.c | 157
> ---------------------------------- 5 files changed, 1 insertions(+),
> 180 deletions(-) delete mode 100644
> drivers/cpufreq/exynos4210-cpufreq.c
>
> diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
> index 0468ad1..0a2a589 100644
> --- a/drivers/cpufreq/Kconfig.arm
> +++ b/drivers/cpufreq/Kconfig.arm
> @@ -19,17 +19,6 @@ config ARM_DT_BL_CPUFREQ
> config ARM_EXYNOS_CPUFREQ
> bool
>
> -config ARM_EXYNOS4210_CPUFREQ
> - bool "SAMSUNG EXYNOS4210"
> - depends on CPU_EXYNOS4210
> - default y
> - select ARM_EXYNOS_CPUFREQ
> - help
> - This adds the CPUFreq driver for Samsung EXYNOS4210
> - SoC (S5PV310 or S5PC210).
> -
> - If in doubt, say N.
> -
> config ARM_EXYNOS4X12_CPUFREQ
> bool "SAMSUNG EXYNOS4x12"
> depends on (SOC_EXYNOS4212 || SOC_EXYNOS4412)
> diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
> index 7494565..ce2abf9 100644
> --- a/drivers/cpufreq/Makefile
> +++ b/drivers/cpufreq/Makefile
> @@ -50,7 +50,6 @@ obj-$(CONFIG_ARM_DT_BL_CPUFREQ) +=
> arm_big_little_dt.o obj-$(CONFIG_ARCH_DAVINCI_DA850) +=
> davinci-cpufreq.o obj-$(CONFIG_UX500_SOC_DB8500) +=
> dbx500-cpufreq.o obj-$(CONFIG_ARM_EXYNOS_CPUFREQ) +=
> exynos-cpufreq.o -obj-$(CONFIG_ARM_EXYNOS4210_CPUFREQ) +=
> exynos4210-cpufreq.o obj-$(CONFIG_ARM_EXYNOS4X12_CPUFREQ) +=
> exynos4x12-cpufreq.o obj-$(CONFIG_ARM_EXYNOS5250_CPUFREQ) +=
> exynos5250-cpufreq.o obj-$(CONFIG_ARM_EXYNOS5440_CPUFREQ) +=
> exynos5440-cpufreq.o diff --git a/drivers/cpufreq/exynos-cpufreq.c
> b/drivers/cpufreq/exynos-cpufreq.c index 4ee3804..eacc7eb 100644
> --- a/drivers/cpufreq/exynos-cpufreq.c
> +++ b/drivers/cpufreq/exynos-cpufreq.c
> @@ -237,9 +237,7 @@ static int exynos_cpufreq_probe(struct
> platform_device *pdev) if (!exynos_info)
> return -ENOMEM;
>
> - if (soc_is_exynos4210())
> - ret = exynos4210_cpufreq_init(exynos_info);
> - else if (soc_is_exynos4212() || soc_is_exynos4412())
> + if (soc_is_exynos4212() || soc_is_exynos4412())
> ret = exynos4x12_cpufreq_init(exynos_info);
> else if (soc_is_exynos5250())
> ret = exynos5250_cpufreq_init(exynos_info);
> diff --git a/drivers/cpufreq/exynos-cpufreq.h
> b/drivers/cpufreq/exynos-cpufreq.h index 3ddade8..1e0afbe 100644
> --- a/drivers/cpufreq/exynos-cpufreq.h
> +++ b/drivers/cpufreq/exynos-cpufreq.h
> @@ -43,14 +43,6 @@ struct exynos_dvfs_info {
> bool (*need_apll_change)(unsigned int, unsigned int);
> };
>
> -#ifdef CONFIG_ARM_EXYNOS4210_CPUFREQ
> -extern int exynos4210_cpufreq_init(struct exynos_dvfs_info *);
> -#else
> -static inline int exynos4210_cpufreq_init(struct exynos_dvfs_info
> *info) -{
> - return -EOPNOTSUPP;
> -}
> -#endif
> #ifdef CONFIG_ARM_EXYNOS4X12_CPUFREQ
> extern int exynos4x12_cpufreq_init(struct exynos_dvfs_info *);
> #else
> diff --git a/drivers/cpufreq/exynos4210-cpufreq.c
> b/drivers/cpufreq/exynos4210-cpufreq.c deleted file mode 100644
> index 40d84c4..0000000
> --- a/drivers/cpufreq/exynos4210-cpufreq.c
> +++ /dev/null
> @@ -1,157 +0,0 @@
> -/*
> - * 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 "exynos-cpufreq.h"
> -
> -static struct clk *cpu_clk;
> -static struct clk *moutcore;
> -static struct clk *mout_mpll;
> -static struct clk *mout_apll;
> -
> -static unsigned int exynos4210_volt_table[] = {
> - 1250000, 1150000, 1050000, 975000, 950000,
> -};
> -
> -static struct cpufreq_frequency_table exynos4210_freq_table[] = {
> - {L0, 1200 * 1000},
> - {L1, 1000 * 1000},
> - {L2, 800 * 1000},
> - {L3, 500 * 1000},
> - {L4, 200 * 1000},
> - {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, EXYNOS4_CLKDIV_CPU);
> -
> - do {
> - tmp = __raw_readl(EXYNOS4_CLKDIV_STATCPU);
> - } while (tmp & 0x1111111);
> -
> - /* Change Divider - CPU1 */
> -
> - tmp = apll_freq_4210[div_index].clk_div_cpu1;
> -
> - __raw_writel(tmp, EXYNOS4_CLKDIV_CPU1);
> -
> - do {
> - tmp = __raw_readl(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(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(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)
> -{
> - unsigned long rate;
> -
> - 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;
> -
> - 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;
> -}

Reviewed-by: Lukasz Majewski <l.majewski@samsung.com>

--
Best regards,

Lukasz Majewski

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