Subject: [PATCH v2 7/7] cpufreq: exynos: remove all exynos specific cpufreq driver support

From: [email-masked] (Lukasz Majewski)
Date: Wed, 05 Feb 2014 12:44:59 +0100

Hi Thomas,

Fist of all, thanks for your patches.

> Hi Lukasz,
> 
> On Mon, Jan 20, 2014 at 1:38 PM, Lukasz Majewski
> <[email-masked]> wrote:
> > Hi Thomas,
> >
> >> From: Thomas Abraham <[email-masked]>
> >>
> >> Exynos4210, Exynos4x12 and Exynos5250 based platforms have switched
> >> over to use cpufreq-cpu0 driver for cpufreq functionality. So the
> >> Exynos specific cpufreq drivers for these platforms can be removed.
> >>
> 
> <snip>
> 
> >> -static unsigned int exynos4x12_volt_table[] = {
> >> -     1350000, 1287500, 1250000, 1187500, 1137500, 1087500,
> >> 1037500,
> >> -     1000000,  987500,  975000,  950000,  925000,  900000,  900000
> >> -};
> >> -
> >> -static struct cpufreq_frequency_table exynos4x12_freq_table[] = {
> >> -     {CPUFREQ_BOOST_FREQ, 1500 * 1000},
> >
> > Here, you are removing BOOST support for Exynos4412, without any
> > code, which brings back this functionality in the new code.
> >
> > I'd propose adding new property to cpus node and during
> > operating-points parsing mark the entry at the
> > cpufreq_frequency_table accordingly.
> 
> I tried doing this as you suggested with [1] but looks like that will
> not go through at this point.

I've read your patches regarding OPP. In my opinion, despite the problem
with further OPP format discussion (which is ongoing and probably will
take some time), there is a palatable solution (presented below).

> The other alternative would be to use
> exynos specific cpufreq drivers only if multiplatform config is not
> selected or use cpufreq-cpu0 if multiplatform config is selected (but
> this is not something I would want to do). With this, there are issues
> like clock blocks encapsulated within the opaque clock type cannot be
> removed since exynos specific cpufreq drivers need it and hence it is
> not really a clean solution. 

It would be a maintenance nightmare. We cannot afford to do such huge
cleanup only partially. The rationale for the whole clean up is to
remove exynosXXXX-cpufreq.c files.

I also share your doubts here. We shall NOT do it this way.

>The other option is to drop the support
> for boost on exynos4x12 for now and reintroduce that when the OPP
> bindings have been finalized. 

So you want to drop the BOOST kernel functionality just because you are
doing clean up and this feature is problematic to provide at new
approach?

> Would that be okay?

It is NOT acceptable. Sorry, but NAK.

> Any other
> suggestions will also be helpful.

For me it would be perfectly fine to see at device tree CPU0 node code
proposed by Nishanth:

operating-points = < Fa Va
	Fb Vb
	Fc Vc
	Fd Vd
	>;  
boost-frequencies = <Fc Fd>;

And then the cpufreq table could be properly modified by marking
relevant frequencies as CPUFREQ_BOOST_FREQ.

> 
> Thanks,
> Thomas.
> 
> >
> >> -     {L1, 1400 * 1000},
> >> -     {L2, 1300 * 1000},
> >> -     {L3, 1200 * 1000},
> >> -     {L4, 1100 * 1000},
> >> -     {L5, 1000 * 1000},
> >> -     {L6,  900 * 1000},
> >> -     {L7,  800 * 1000},
> >> -     {L8,  700 * 1000},
> >> -     {L9,  600 * 1000},
> >> -     {L10, 500 * 1000},
> >> -     {L11, 400 * 1000},
> >> -     {L12, 300 * 1000},
> >> -     {L13, 200 * 1000},
> >> -     {0, CPUFREQ_TABLE_END},
> >> -};
> >> -
> >> -static struct apll_freq *apll_freq_4x12;
> >> -
> >> -static struct apll_freq apll_freq_4212[] = {
> >> -     /*
> >> -      * values:
> >> -      * freq
> >> -      * clock divider for CORE, COREM0, COREM1, PERIPH, ATB,
> >> PCLK_DBG, APLL, CORE2
> >> -      * clock divider for COPY, HPM, RESERVED
> >> -      * PLL M, P, S
> >> -      */
> >> -     APLL_FREQ(1500, 0, 3, 7, 0, 6, 1, 2, 0, 6, 2, 0, 250, 4, 0),
> >> -     APLL_FREQ(1400, 0, 3, 7, 0, 6, 1, 2, 0, 6, 2, 0, 175, 3, 0),
> >> -     APLL_FREQ(1300, 0, 3, 7, 0, 5, 1, 2, 0, 5, 2, 0, 325, 6, 0),
> >> -     APLL_FREQ(1200, 0, 3, 7, 0, 5, 1, 2, 0, 5, 2, 0, 200, 4, 0),
> >> -     APLL_FREQ(1100, 0, 3, 6, 0, 4, 1, 2, 0, 4, 2, 0, 275, 6, 0),
> >> -     APLL_FREQ(1000, 0, 2, 5, 0, 4, 1, 1, 0, 4, 2, 0, 125, 3, 0),
> >> -     APLL_FREQ(900,  0, 2, 5, 0, 3, 1, 1, 0, 3, 2, 0, 150, 4, 0),
> >> -     APLL_FREQ(800,  0, 2, 5, 0, 3, 1, 1, 0, 3, 2, 0, 100, 3, 0),
> >> -     APLL_FREQ(700,  0, 2, 4, 0, 3, 1, 1, 0, 3, 2, 0, 175, 3, 1),
> >> -     APLL_FREQ(600,  0, 2, 4, 0, 3, 1, 1, 0, 3, 2, 0, 200, 4, 1),
> >> -     APLL_FREQ(500,  0, 2, 4, 0, 3, 1, 1, 0, 3, 2, 0, 125, 3, 1),
> >> -     APLL_FREQ(400,  0, 2, 4, 0, 3, 1, 1, 0, 3, 2, 0, 100, 3, 1),
> >> -     APLL_FREQ(300,  0, 2, 4, 0, 2, 1, 1, 0, 3, 2, 0, 200, 4, 2),
> >> -     APLL_FREQ(200,  0, 1, 3, 0, 1, 1, 1, 0, 3, 2, 0, 100, 3, 2),
> >> -};
> >> -
> >> -static struct apll_freq apll_freq_4412[] = {
> >> -     /*
> >> -      * values:
> >> -      * freq
> >> -      * clock divider for CORE, COREM0, COREM1, PERIPH, ATB,
> >> PCLK_DBG, APLL, CORE2
> >> -      * clock divider for COPY, HPM, CORES
> >> -      * PLL M, P, S
> >> -      */
> >> -     APLL_FREQ(1500, 0, 3, 7, 0, 6, 1, 2, 0, 6, 0, 7, 250, 4, 0),
> >> -     APLL_FREQ(1400, 0, 3, 7, 0, 6, 1, 2, 0, 6, 0, 6, 175, 3, 0),
> >> -     APLL_FREQ(1300, 0, 3, 7, 0, 5, 1, 2, 0, 5, 0, 6, 325, 6, 0),
> >> -     APLL_FREQ(1200, 0, 3, 7, 0, 5, 1, 2, 0, 5, 0, 5, 200, 4, 0),
> >> -     APLL_FREQ(1100, 0, 3, 6, 0, 4, 1, 2, 0, 4, 0, 5, 275, 6, 0),
> >> -     APLL_FREQ(1000, 0, 2, 5, 0, 4, 1, 1, 0, 4, 0, 4, 125, 3, 0),
> >> -     APLL_FREQ(900,  0, 2, 5, 0, 3, 1, 1, 0, 3, 0, 4, 150, 4, 0),
> >> -     APLL_FREQ(800,  0, 2, 5, 0, 3, 1, 1, 0, 3, 0, 3, 100, 3, 0),
> >> -     APLL_FREQ(700,  0, 2, 4, 0, 3, 1, 1, 0, 3, 0, 3, 175, 3, 1),
> >> -     APLL_FREQ(600,  0, 2, 4, 0, 3, 1, 1, 0, 3, 0, 2, 200, 4, 1),
> >> -     APLL_FREQ(500,  0, 2, 4, 0, 3, 1, 1, 0, 3, 0, 2, 125, 3, 1),
> >> -     APLL_FREQ(400,  0, 2, 4, 0, 3, 1, 1, 0, 3, 0, 1, 100, 3, 1),
> >> -     APLL_FREQ(300,  0, 2, 4, 0, 2, 1, 1, 0, 3, 0, 1, 200, 4, 2),
> >> -     APLL_FREQ(200,  0, 1, 3, 0, 1, 1, 1, 0, 3, 0, 0, 100, 3, 2),
> >> -};
> >> -
> >> -static void exynos4x12_set_clkdiv(unsigned int div_index)
> >> -{
> >> -     unsigned int tmp;
> >> -     unsigned int stat_cpu1;
> >> -
> >> -     /* Change Divider - CPU0 */
> >> -
> >> -     tmp = apll_freq_4x12[div_index].clk_div_cpu0;
> >> -
> >> -     __raw_writel(tmp, EXYNOS4_CLKDIV_CPU);
> >> -
> >> -     while (__raw_readl(EXYNOS4_CLKDIV_STATCPU) & 0x11111111)
> >> -             cpu_relax();
> >> -
> >> -     /* Change Divider - CPU1 */
> >> -     tmp = apll_freq_4x12[div_index].clk_div_cpu1;
> >> -
> >> -     __raw_writel(tmp, EXYNOS4_CLKDIV_CPU1);
> >> -     if (soc_is_exynos4212())
> >> -             stat_cpu1 = 0x11;
> >> -     else
> >> -             stat_cpu1 = 0x111;
> >> -
> >> -     while (__raw_readl(EXYNOS4_CLKDIV_STATCPU1) & stat_cpu1)
> >> -             cpu_relax();
> >> -}
> >> -
> >> -static void exynos4x12_set_apll(unsigned int index)
> >> -{
> >> -     unsigned int tmp, freq = apll_freq_4x12[index].freq;
> >> -
> >> -     /* MUX_CORE_SEL = MPLL, ARMCLK uses MPLL for lock time */
> >> -     clk_set_parent(moutcore, mout_mpll);
> >> -
> >> -     do {
> >> -             cpu_relax();
> >> -             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 {
> >> -             cpu_relax();
> >> -             tmp = __raw_readl(EXYNOS4_CLKMUX_STATCPU);
> >> -             tmp &= EXYNOS4_CLKMUX_STATCPU_MUXCORE_MASK;
> >> -     } while (tmp != (0x1 << EXYNOS4_CLKSRC_CPU_MUXCORE_SHIFT));
> >> -}
> >> -
> >> -static void exynos4x12_set_frequency(unsigned int old_index,
> >> -                               unsigned int new_index)
> >> -{
> >> -     if (old_index > new_index) {
> >> -             exynos4x12_set_clkdiv(new_index);
> >> -             exynos4x12_set_apll(new_index);
> >> -     } else if (old_index < new_index) {
> >> -             exynos4x12_set_apll(new_index);
> >> -             exynos4x12_set_clkdiv(new_index);
> >> -     }
> >> -}
> >> -
> >> -int exynos4x12_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;
> >> -
> >> -     if (soc_is_exynos4212())
> >> -             apll_freq_4x12 = apll_freq_4212;
> >> -     else
> >> -             apll_freq_4x12 = apll_freq_4412;
> >> -
> >> -     info->mpll_freq_khz = rate;
> >> -     /* 800Mhz */
> >> -     info->pll_safe_idx = L7;
> >> -     info->cpu_clk = cpu_clk;
> >> -     info->volt_table = exynos4x12_volt_table;
> >> -     info->freq_table = exynos4x12_freq_table;
> >> -     info->set_freq = exynos4x12_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;
> >> -}
> >> diff --git a/drivers/cpufreq/exynos5250-cpufreq.c
> >> b/drivers/cpufreq/exynos5250-cpufreq.c deleted file mode 100644
> >> index 5f90b82..0000000
> >> --- a/drivers/cpufreq/exynos5250-cpufreq.c
> >> +++ /dev/null
> >> @@ -1,183 +0,0 @@
> >> -/*
> >> - * Copyright (c) 2010-20122Samsung Electronics Co., Ltd.
> >> - *           http://www.samsung.com
> >> - *
> >> - * EXYNOS5250 - 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 <mach/map.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 exynos5250_volt_table[] = {
> >> -     1300000, 1250000, 1225000, 1200000, 1150000,
> >> -     1125000, 1100000, 1075000, 1050000, 1025000,
> >> -     1012500, 1000000,  975000,  950000,  937500,
> >> -     925000
> >> -};
> >> -
> >> -static struct cpufreq_frequency_table exynos5250_freq_table[] = {
> >> -     {L0, 1700 * 1000},
> >> -     {L1, 1600 * 1000},
> >> -     {L2, 1500 * 1000},
> >> -     {L3, 1400 * 1000},
> >> -     {L4, 1300 * 1000},
> >> -     {L5, 1200 * 1000},
> >> -     {L6, 1100 * 1000},
> >> -     {L7, 1000 * 1000},
> >> -     {L8,  900 * 1000},
> >> -     {L9,  800 * 1000},
> >> -     {L10, 700 * 1000},
> >> -     {L11, 600 * 1000},
> >> -     {L12, 500 * 1000},
> >> -     {L13, 400 * 1000},
> >> -     {L14, 300 * 1000},
> >> -     {L15, 200 * 1000},
> >> -     {0, CPUFREQ_TABLE_END},
> >> -};
> >> -
> >> -static struct apll_freq apll_freq_5250[] = {
> >> -     /*
> >> -      * values:
> >> -      * freq
> >> -      * clock divider for ARM, CPUD, ACP, PERIPH, ATB, PCLK_DBG,
> >> APLL, ARM2
> >> -      * clock divider for COPY, HPM, RESERVED
> >> -      * PLL M, P, S
> >> -      */
> >> -     APLL_FREQ(1700, 0, 3, 7, 7, 7, 3, 5, 0, 0, 2, 0, 425, 6, 0),
> >> -     APLL_FREQ(1600, 0, 3, 7, 7, 7, 1, 4, 0, 0, 2, 0, 200, 3, 0),
> >> -     APLL_FREQ(1500, 0, 2, 7, 7, 7, 1, 4, 0, 0, 2, 0, 250, 4, 0),
> >> -     APLL_FREQ(1400, 0, 2, 7, 7, 6, 1, 4, 0, 0, 2, 0, 175, 3, 0),
> >> -     APLL_FREQ(1300, 0, 2, 7, 7, 6, 1, 3, 0, 0, 2, 0, 325, 6, 0),
> >> -     APLL_FREQ(1200, 0, 2, 7, 7, 5, 1, 3, 0, 0, 2, 0, 200, 4, 0),
> >> -     APLL_FREQ(1100, 0, 3, 7, 7, 5, 1, 3, 0, 0, 2, 0, 275, 6, 0),
> >> -     APLL_FREQ(1000, 0, 1, 7, 7, 4, 1, 2, 0, 0, 2, 0, 125, 3, 0),
> >> -     APLL_FREQ(900,  0, 1, 7, 7, 4, 1, 2, 0, 0, 2, 0, 150, 4, 0),
> >> -     APLL_FREQ(800,  0, 1, 7, 7, 4, 1, 2, 0, 0, 2, 0, 100, 3, 0),
> >> -     APLL_FREQ(700,  0, 1, 7, 7, 3, 1, 1, 0, 0, 2, 0, 175, 3, 1),
> >> -     APLL_FREQ(600,  0, 1, 7, 7, 3, 1, 1, 0, 0, 2, 0, 200, 4, 1),
> >> -     APLL_FREQ(500,  0, 1, 7, 7, 2, 1, 1, 0, 0, 2, 0, 125, 3, 1),
> >> -     APLL_FREQ(400,  0, 1, 7, 7, 2, 1, 1, 0, 0, 2, 0, 100, 3, 1),
> >> -     APLL_FREQ(300,  0, 1, 7, 7, 1, 1, 1, 0, 0, 2, 0, 200, 4, 2),
> >> -     APLL_FREQ(200,  0, 1, 7, 7, 1, 1, 1, 0, 0, 2, 0, 100, 3, 2),
> >> -};
> >> -
> >> -static void set_clkdiv(unsigned int div_index)
> >> -{
> >> -     unsigned int tmp;
> >> -
> >> -     /* Change Divider - CPU0 */
> >> -
> >> -     tmp = apll_freq_5250[div_index].clk_div_cpu0;
> >> -
> >> -     __raw_writel(tmp, EXYNOS5_CLKDIV_CPU0);
> >> -
> >> -     while (__raw_readl(EXYNOS5_CLKDIV_STATCPU0) & 0x11111111)
> >> -             cpu_relax();
> >> -
> >> -     /* Change Divider - CPU1 */
> >> -     tmp = apll_freq_5250[div_index].clk_div_cpu1;
> >> -
> >> -     __raw_writel(tmp, EXYNOS5_CLKDIV_CPU1);
> >> -
> >> -     while (__raw_readl(EXYNOS5_CLKDIV_STATCPU1) & 0x11)
> >> -             cpu_relax();
> >> -}
> >> -
> >> -static void set_apll(unsigned int index)
> >> -{
> >> -     unsigned int tmp;
> >> -     unsigned int freq = apll_freq_5250[index].freq;
> >> -
> >> -     /* MUX_CORE_SEL = MPLL, ARMCLK uses MPLL for lock time */
> >> -     clk_set_parent(moutcore, mout_mpll);
> >> -
> >> -     do {
> >> -             cpu_relax();
> >> -             tmp = (__raw_readl(EXYNOS5_CLKMUX_STATCPU) >> 16);
> >> -             tmp &= 0x7;
> >> -     } while (tmp != 0x2);
> >> -
> >> -     clk_set_rate(mout_apll, freq * 1000);
> >> -
> >> -     /* MUX_CORE_SEL = APLL */
> >> -     clk_set_parent(moutcore, mout_apll);
> >> -
> >> -     do {
> >> -             cpu_relax();
> >> -             tmp = __raw_readl(EXYNOS5_CLKMUX_STATCPU);
> >> -             tmp &= (0x7 << 16);
> >> -     } while (tmp != (0x1 << 16));
> >> -}
> >> -
> >> -static void exynos5250_set_frequency(unsigned int old_index,
> >> -                               unsigned int new_index)
> >> -{
> >> -     if (old_index > new_index) {
> >> -             set_clkdiv(new_index);
> >> -             set_apll(new_index);
> >> -     } else if (old_index < new_index) {
> >> -             set_apll(new_index);
> >> -             set_clkdiv(new_index);
> >> -     }
> >> -}
> >> -
> >> -int exynos5250_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, "mout_cpu");
> >> -     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 = L9;
> >> -     info->cpu_clk = cpu_clk;
> >> -     info->volt_table = exynos5250_volt_table;
> >> -     info->freq_table = exynos5250_freq_table;
> >> -     info->set_freq = exynos5250_set_frequency;
> >> -
> >> -     return 0;
> >> -
> >> -err_mout_apll:
> >> -     clk_put(mout_mpll);
> >> -err_mout_mpll:
> >> -     clk_put(moutcore);
> >> -err_moutcore:
> >> -     clk_put(cpu_clk);
> >> -
> >> -     pr_err("%s: failed initialization\n", __func__);
> >> -     return -EINVAL;
> >> -}
> >
> >
> >
> > --
> > Best regards,
> >
> > Lukasz Majewski
> >
> > Samsung R&D Institute Poland (SRPOL) | Linux Platform Group
> --
> To unsubscribe from this list: send the line "unsubscribe cpufreq" in
> the body of a message to majordomo at vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 

-- 
Best regards,

Lukasz Majewski

Samsung R&D Institute Poland (SRPOL) | Linux Platform Group