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Message-ID: <1627215.GFg6tQENRA@vostro.rjw.lan>
Date: Thu, 17 Oct 2013 00:58:42 +0200
From: "Rafael J. Wysocki" <rjw@...ysocki.net>
To: Lukasz Majewski <l.majewski@...sung.com>
Cc: Viresh Kumar <viresh.kumar@...aro.org>,
"cpufreq@...r.kernel.org" <cpufreq@...r.kernel.org>,
Linux PM list <linux-pm@...r.kernel.org>,
Jonghwa Lee <jonghwa3.lee@...sung.com>,
Lukasz Majewski <l.majewski@...ess.pl>,
linux-kernel <linux-kernel@...r.kernel.org>,
Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>,
Myungjoo Ham <myungjoo.ham@...sung.com>,
Yadwinder Singh Brar <yadi.brar01@...il.com>,
Tomasz Figa <t.figa@...sung.com>
Subject: Re: [PATCH v2 2/2] cpufreq: exynos4210: Use the common clock framework to set APLL clock rate
On Wednesday, October 09, 2013 02:08:43 PM Lukasz Majewski wrote:
> In the exynos4210_set_apll() function, the APLL frequency is set with
> direct register manipulation.
>
> Such approach is not allowed in the common clock framework. The frequency
> is changed, but the corresponding clock value is not updated. This causes
> wrong frequency read from cpufreq's cpuinfo_cur_freq sysfs attribute.
>
> Also direct manipulation with PLL's S parameter has been removed. It is
> already done at PLL35xx code.
>
> Tested at:
> - Exynos4210 - Trats board (linux 3.12-rc4)
>
> Signed-off-by: Lukasz Majewski <l.majewski@...sung.com>
I need an ACK or Reviewed-by from someone in the CC list here.
Thanks!
> Changes for v2:
> - Remove PLL's S parameter setting via registers. It is now done with PLL35xx
> code.
> - Remove exynos4210_pms_change() function
>
> Change-Id: Ie5fb3c7946ba77b6f3d5e91af72eef2fd06770c1
> ---
> drivers/cpufreq/exynos4210-cpufreq.c | 67 ++++------------------------------
> 1 file changed, 8 insertions(+), 59 deletions(-)
>
> diff --git a/drivers/cpufreq/exynos4210-cpufreq.c b/drivers/cpufreq/exynos4210-cpufreq.c
> index add7fbe..f2c7506 100644
> --- a/drivers/cpufreq/exynos4210-cpufreq.c
> +++ b/drivers/cpufreq/exynos4210-cpufreq.c
> @@ -81,9 +81,9 @@ static void exynos4210_set_clkdiv(unsigned int div_index)
>
> static void exynos4210_set_apll(unsigned int index)
> {
> - unsigned int tmp;
> + unsigned int tmp, freq = apll_freq_4210[index].freq;
>
> - /* 1. MUX_CORE_SEL = MPLL, ARMCLK uses MPLL for lock time */
> + /* MUX_CORE_SEL = MPLL, ARMCLK uses MPLL for lock time */
> clk_set_parent(moutcore, mout_mpll);
>
> do {
> @@ -92,21 +92,9 @@ static void exynos4210_set_apll(unsigned int index)
> tmp &= 0x7;
> } while (tmp != 0x2);
>
> - /* 2. Set APLL Lock time */
> - __raw_writel(EXYNOS4_APLL_LOCKTIME, EXYNOS4_APLL_LOCK);
> -
> - /* 3. Change PLL PMS values */
> - tmp = __raw_readl(EXYNOS4_APLL_CON0);
> - tmp &= ~((0x3ff << 16) | (0x3f << 8) | (0x7 << 0));
> - tmp |= apll_freq_4210[index].mps;
> - __raw_writel(tmp, EXYNOS4_APLL_CON0);
> + clk_set_rate(mout_apll, freq * 1000);
>
> - /* 4. wait_lock_time */
> - do {
> - tmp = __raw_readl(EXYNOS4_APLL_CON0);
> - } while (!(tmp & (0x1 << EXYNOS4_APLLCON0_LOCKED_SHIFT)));
> -
> - /* 5. MUX_CORE_SEL = APLL */
> + /* MUX_CORE_SEL = APLL */
> clk_set_parent(moutcore, mout_apll);
>
> do {
> @@ -115,53 +103,15 @@ static void exynos4210_set_apll(unsigned int index)
> } while (tmp != (0x1 << EXYNOS4_CLKSRC_CPU_MUXCORE_SHIFT));
> }
>
> -static bool exynos4210_pms_change(unsigned int old_index, unsigned int new_index)
> -{
> - unsigned int old_pm = apll_freq_4210[old_index].mps >> 8;
> - unsigned int new_pm = apll_freq_4210[new_index].mps >> 8;
> -
> - return (old_pm == new_pm) ? 0 : 1;
> -}
> -
> static void exynos4210_set_frequency(unsigned int old_index,
> unsigned int new_index)
> {
> - unsigned int tmp;
> -
> if (old_index > new_index) {
> - if (!exynos4210_pms_change(old_index, new_index)) {
> - /* 1. Change the system clock divider values */
> - exynos4210_set_clkdiv(new_index);
> -
> - /* 2. Change just s value in apll m,p,s value */
> - tmp = __raw_readl(EXYNOS4_APLL_CON0);
> - tmp &= ~(0x7 << 0);
> - tmp |= apll_freq_4210[new_index].mps & 0x7;
> - __raw_writel(tmp, EXYNOS4_APLL_CON0);
> - } else {
> - /* Clock Configuration Procedure */
> - /* 1. Change the system clock divider values */
> - exynos4210_set_clkdiv(new_index);
> - /* 2. Change the apll m,p,s value */
> - exynos4210_set_apll(new_index);
> - }
> + exynos4210_set_clkdiv(new_index);
> + exynos4210_set_apll(new_index);
> } else if (old_index < new_index) {
> - if (!exynos4210_pms_change(old_index, new_index)) {
> - /* 1. Change just s value in apll m,p,s value */
> - tmp = __raw_readl(EXYNOS4_APLL_CON0);
> - tmp &= ~(0x7 << 0);
> - tmp |= apll_freq_4210[new_index].mps & 0x7;
> - __raw_writel(tmp, EXYNOS4_APLL_CON0);
> -
> - /* 2. Change the system clock divider values */
> - exynos4210_set_clkdiv(new_index);
> - } else {
> - /* Clock Configuration Procedure */
> - /* 1. Change the apll m,p,s value */
> - exynos4210_set_apll(new_index);
> - /* 2. Change the system clock divider values */
> - exynos4210_set_clkdiv(new_index);
> - }
> + exynos4210_set_apll(new_index);
> + exynos4210_set_clkdiv(new_index);
> }
> }
>
> @@ -194,7 +144,6 @@ int exynos4210_cpufreq_init(struct exynos_dvfs_info *info)
> info->volt_table = exynos4210_volt_table;
> info->freq_table = exynos4210_freq_table;
> info->set_freq = exynos4210_set_frequency;
> - info->need_apll_change = exynos4210_pms_change;
>
> return 0;
>
>
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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