| Message ID | 1430134846-24320-5-git-send-email-sudeep.holla@arm.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On 27 April 2015 at 17:10, Sudeep Holla <sudeep.holla@arm.com> wrote: > diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm > index 4f3dbc8cf729..9e678bf1687c 100644 > --- a/drivers/cpufreq/Kconfig.arm > +++ b/drivers/cpufreq/Kconfig.arm > @@ -24,6 +24,15 @@ config ARM_VEXPRESS_SPC_CPUFREQ > This add the CPUfreq driver support for Versatile Express > big.LITTLE platforms using SPC for power management. > > +config ARM_SCPI_CPUFREQ > + tristate "SCPI based CPUfreq driver" > + depends on ARM_BIG_LITTLE_CPUFREQ && ARM_SCPI_PROTOCOL > + help > + This add the CPUfreq driver support for ARM big.LITTLE platforms > + using SCPI interface for CPU power management. > + > + This driver works only if firmware the supporting CPU DVFS adhere > + to SCPI protocol. Wanna reword that ? > > config ARM_EXYNOS_CPUFREQ > tristate "SAMSUNG EXYNOS CPUfreq Driver" > diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile > index cdce92ae2e8b..02fc9f849d4b 100644 > --- a/drivers/cpufreq/Makefile > +++ b/drivers/cpufreq/Makefile > @@ -79,6 +79,7 @@ obj-$(CONFIG_ARM_SA1110_CPUFREQ) += sa1110-cpufreq.o > obj-$(CONFIG_ARM_SPEAR_CPUFREQ) += spear-cpufreq.o > obj-$(CONFIG_ARM_TEGRA_CPUFREQ) += tegra-cpufreq.o > obj-$(CONFIG_ARM_VEXPRESS_SPC_CPUFREQ) += vexpress-spc-cpufreq.o > +obj-$(CONFIG_ARM_SCPI_CPUFREQ) += scpi-cpufreq.o > > ################################################################################## > # PowerPC platform drivers > diff --git a/drivers/cpufreq/scpi-cpufreq.c b/drivers/cpufreq/scpi-cpufreq.c > new file mode 100644 > index 000000000000..4c2c11a9dfc6 > --- /dev/null > +++ b/drivers/cpufreq/scpi-cpufreq.c > @@ -0,0 +1,103 @@ > +/* > + * SCPI CPUFreq Interface driver > + * > + * It provides necessary ops to arm_big_little cpufreq driver. > + * > + * Copyright (C) 2015 ARM Ltd. > + * Sudeep Holla <sudeep.holla@arm.com> > + * > + * 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. > + * > + * This program is distributed "as is" WITHOUT ANY WARRANTY of any > + * kind, whether express or implied; without even the implied warranty > + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + */ > + > +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt > + > +#include <linux/cpufreq.h> > +#include <linux/module.h> > +#include <linux/platform_device.h> > +#include <linux/pm_opp.h> > +#include <linux/scpi_protocol.h> > +#include <linux/types.h> > + > +#include "arm_big_little.h" > + > +static struct scpi_ops *scpi_ops; > + > +static int scpi_init_opp_table(struct device *cpu_dev) > +{ > + u8 domain = topology_physical_package_id(cpu_dev->id); > + struct scpi_dvfs_info *info; > + struct scpi_opp *opp; > + int idx, ret = 0; > + > + if ((dev_pm_opp_get_opp_count(cpu_dev)) > 0) > + return 0; Why, who would have added it ? > + info = scpi_ops->dvfs_get_info(domain); Isn't calling this twice costly for getting the same information ? > + if (IS_ERR(info)) > + return PTR_ERR(info); > + > + opp = info->opps; > + if (!opp) > + return -EIO; > + > + for (idx = 0; idx < info->count; idx++, opp++) { > + ret = dev_pm_opp_add(cpu_dev, opp->freq, opp->m_volt * 1000); > + if (ret) { > + dev_warn(cpu_dev, "failed to add opp %uHz %umV\n", > + opp->freq, opp->m_volt); Don't you want to free earlier OPPs here ? > + return ret; > + } > + } > + return ret; > +} > + > +static int scpi_get_transition_latency(struct device *cpu_dev) > +{ > + u8 domain = topology_physical_package_id(cpu_dev->id); > + struct scpi_dvfs_info *info; > + > + info = scpi_ops->dvfs_get_info(domain); > + if (IS_ERR(info)) > + return PTR_ERR(info); > + > + return info->latency; > +} > + > +static struct cpufreq_arm_bL_ops scpi_cpufreq_ops = { > + .name = "scpi", > + .get_transition_latency = scpi_get_transition_latency, > + .init_opp_table = scpi_init_opp_table, Don't want to free/remove OPPs ? > +}; > + > +static int scpi_cpufreq_probe(struct platform_device *pdev) > +{ > + scpi_ops = get_scpi_ops(); > + if (!scpi_ops) > + return -EIO; > + > + return bL_cpufreq_register(&scpi_cpufreq_ops); > +} > + > +static int scpi_cpufreq_remove(struct platform_device *pdev) > +{ > + bL_cpufreq_unregister(&scpi_cpufreq_ops); > + return 0; > +} > + > +static struct platform_driver scpi_cpufreq_platdrv = { > + .driver = { > + .name = "scpi-cpufreq", > + .owner = THIS_MODULE, > + }, > + .probe = scpi_cpufreq_probe, > + .remove = scpi_cpufreq_remove, > +}; > +module_platform_driver(scpi_cpufreq_platdrv); > + > +MODULE_LICENSE("GPL"); GPL V2 ? Author/Description missing .. > -- > 1.9.1 > -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Viresh, Thanks for the review. On 29/04/15 06:44, Viresh Kumar wrote: > On 27 April 2015 at 17:10, Sudeep Holla <sudeep.holla@arm.com> wrote: >> diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm >> index 4f3dbc8cf729..9e678bf1687c 100644 >> --- a/drivers/cpufreq/Kconfig.arm >> +++ b/drivers/cpufreq/Kconfig.arm >> @@ -24,6 +24,15 @@ config ARM_VEXPRESS_SPC_CPUFREQ >> This add the CPUfreq driver support for Versatile Express >> big.LITTLE platforms using SPC for power management. >> >> +config ARM_SCPI_CPUFREQ >> + tristate "SCPI based CPUfreq driver" >> + depends on ARM_BIG_LITTLE_CPUFREQ && ARM_SCPI_PROTOCOL >> + help >> + This add the CPUfreq driver support for ARM big.LITTLE platforms >> + using SCPI interface for CPU power management. >> + >> + This driver works only if firmware the supporting CPU DVFS adhere >> + to SCPI protocol. > > Wanna reword that ? > Ok [...] >> +static int scpi_init_opp_table(struct device *cpu_dev) >> +{ >> + u8 domain = topology_physical_package_id(cpu_dev->id); >> + struct scpi_dvfs_info *info; >> + struct scpi_opp *opp; >> + int idx, ret = 0; >> + >> + if ((dev_pm_opp_get_opp_count(cpu_dev)) > 0) >> + return 0; > > Why, who would have added it ? > IIRC, it was added to prevent spurious duplicate OPP addition messages during CPU hotplug. I will check it again. >> + info = scpi_ops->dvfs_get_info(domain); > > Isn't calling this twice costly for getting the same information ? > No the SCPI protocol saves them and return just the pointer if it's already populated. >> + if (IS_ERR(info)) >> + return PTR_ERR(info); >> + >> + opp = info->opps; >> + if (!opp) >> + return -EIO; >> + >> + for (idx = 0; idx < info->count; idx++, opp++) { >> + ret = dev_pm_opp_add(cpu_dev, opp->freq, opp->m_volt * 1000); >> + if (ret) { >> + dev_warn(cpu_dev, "failed to add opp %uHz %umV\n", >> + opp->freq, opp->m_volt); > > Don't you want to free earlier OPPs here ? > Make sense will fix. >> +static struct cpufreq_arm_bL_ops scpi_cpufreq_ops = { >> + .name = "scpi", >> + .get_transition_latency = scpi_get_transition_latency, >> + .init_opp_table = scpi_init_opp_table, > > Don't want to free/remove OPPs ? > Ah I see a new function is added, will fix it. In-fact this driver was written before that and was held up since the firmware was not stable. [...] >> +static struct platform_driver scpi_cpufreq_platdrv = { >> + .driver = { >> + .name = "scpi-cpufreq", >> + .owner = THIS_MODULE, >> + }, >> + .probe = scpi_cpufreq_probe, >> + .remove = scpi_cpufreq_remove, >> +}; >> +module_platform_driver(scpi_cpufreq_platdrv); >> + >> +MODULE_LICENSE("GPL"); > > GPL V2 ? > > Author/Description missing .. > Will fix it in next version. Regards, Sudeep -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, 2015-04-27 at 12:40 +0100, Sudeep Holla wrote: > On some ARM based systems, a separate Cortex-M based System Control > Processor(SCP) provides the overall power, clock, reset and system > control including CPU DVFS. SCPI Message Protocol is used to > communicate with the SCPI. > > This patch adds a interface driver for adding OPPs and registering > the arm_big_little cpufreq driver for such systems. > > Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> > Cc: Viresh Kumar <viresh.kumar@linaro.org> > Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> > Cc: linux-pm@vger.kernel.org > --- > drivers/cpufreq/Kconfig.arm | 9 ++++ > drivers/cpufreq/Makefile | 1 + > drivers/cpufreq/scpi-cpufreq.c | 103 +++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 113 insertions(+) > create mode 100644 drivers/cpufreq/scpi-cpufreq.c > > diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm > index 4f3dbc8cf729..9e678bf1687c 100644 > --- a/drivers/cpufreq/Kconfig.arm > +++ b/drivers/cpufreq/Kconfig.arm > @@ -24,6 +24,15 @@ config ARM_VEXPRESS_SPC_CPUFREQ > This add the CPUfreq driver support for Versatile Express > big.LITTLE platforms using SPC for power management. > > +config ARM_SCPI_CPUFREQ > + tristate "SCPI based CPUfreq driver" > + depends on ARM_BIG_LITTLE_CPUFREQ && ARM_SCPI_PROTOCOL And ARM_BIG_LITTLE_CPUFREQ depends on CONFIG_ARM, so we can't build this for arm64, which is the only platform (Juno) we have to run these patches on. Unless you're prepared for a horrid hack... https://github.com/ARM-software/linux/commit/b9ceaa0cbd7c57d57ee7e69146cc627697570f6e or a pair of less horrid ones... http://git.linaro.org/kernel/linux-linaro-tracking.git/commit/4b5dd8ff98613b7e90c8f3214522a00ab6900fe9 http://git.linaro.org/kernel/linux-linaro-tracking.git/commit/8641dbfe253f6a9061742ca11f769fc1d82c2aaa Any reason why the above two aren't suitable for mainline Linux? The second was actually committed then reverted because it broke arm64 builds, but the other patch fixes that.
On 01/05/15 14:19, Jon Medhurst (Tixy) wrote: > On Mon, 2015-04-27 at 12:40 +0100, Sudeep Holla wrote: >> On some ARM based systems, a separate Cortex-M based System Control >> Processor(SCP) provides the overall power, clock, reset and system >> control including CPU DVFS. SCPI Message Protocol is used to >> communicate with the SCPI. >> >> This patch adds a interface driver for adding OPPs and registering >> the arm_big_little cpufreq driver for such systems. >> >> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> >> Cc: Viresh Kumar <viresh.kumar@linaro.org> >> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> >> Cc: linux-pm@vger.kernel.org >> --- >> drivers/cpufreq/Kconfig.arm | 9 ++++ >> drivers/cpufreq/Makefile | 1 + >> drivers/cpufreq/scpi-cpufreq.c | 103 +++++++++++++++++++++++++++++++++++++++++ >> 3 files changed, 113 insertions(+) >> create mode 100644 drivers/cpufreq/scpi-cpufreq.c >> >> diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm >> index 4f3dbc8cf729..9e678bf1687c 100644 >> --- a/drivers/cpufreq/Kconfig.arm >> +++ b/drivers/cpufreq/Kconfig.arm >> @@ -24,6 +24,15 @@ config ARM_VEXPRESS_SPC_CPUFREQ >> This add the CPUfreq driver support for Versatile Express >> big.LITTLE platforms using SPC for power management. >> >> +config ARM_SCPI_CPUFREQ >> + tristate "SCPI based CPUfreq driver" >> + depends on ARM_BIG_LITTLE_CPUFREQ && ARM_SCPI_PROTOCOL > > And ARM_BIG_LITTLE_CPUFREQ depends on CONFIG_ARM, so we can't build this > for arm64, which is the only platform (Juno) we have to run these > patches on. Yes I know > Unless you're prepared for a horrid hack... > https://github.com/ARM-software/linux/commit/b9ceaa0cbd7c57d57ee7e69146cc627697570f6e I need to check if it can be improved before I post on the list and hence dropped it in the first version of this patch-set. > or a pair of less horrid ones... > http://git.linaro.org/kernel/linux-linaro-tracking.git/commit/4b5dd8ff98613b7e90c8f3214522a00ab6900fe9 No not this one, this was already discussed long back I believe. It doesn't make sense to add bl-switcher for ARM64 IMO. > http://git.linaro.org/kernel/linux-linaro-tracking.git/commit/8641dbfe253f6a9061742ca11f769fc1d82c2aaa > Yes the Kconfig changes looks better than what I have now. > Any reason why the above two aren't suitable for mainline Linux? The > second was actually committed then reverted because it broke arm64 > builds, but the other patch fixes that. > Yes IMO since arm-big-little also supports multi-cluster cpufreq(yes I know it can be merged into cpufreq-dt once we have OPPv2 bindings, but until then), it should handle the config where CONFIG_BL_SWITCHER=n and that's what I have attempted in my patch above. -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, 2015-05-01 at 14:32 +0100, Sudeep Holla wrote: > > On 01/05/15 14:19, Jon Medhurst (Tixy) wrote: > > On Mon, 2015-04-27 at 12:40 +0100, Sudeep Holla wrote: > >> On some ARM based systems, a separate Cortex-M based System Control > >> Processor(SCP) provides the overall power, clock, reset and system > >> control including CPU DVFS. SCPI Message Protocol is used to > >> communicate with the SCPI. > >> > >> This patch adds a interface driver for adding OPPs and registering > >> the arm_big_little cpufreq driver for such systems. > >> > >> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> > >> Cc: Viresh Kumar <viresh.kumar@linaro.org> > >> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> > >> Cc: linux-pm@vger.kernel.org > >> --- > >> drivers/cpufreq/Kconfig.arm | 9 ++++ > >> drivers/cpufreq/Makefile | 1 + > >> drivers/cpufreq/scpi-cpufreq.c | 103 +++++++++++++++++++++++++++++++++++++++++ > >> 3 files changed, 113 insertions(+) > >> create mode 100644 drivers/cpufreq/scpi-cpufreq.c > >> > >> diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm > >> index 4f3dbc8cf729..9e678bf1687c 100644 > >> --- a/drivers/cpufreq/Kconfig.arm > >> +++ b/drivers/cpufreq/Kconfig.arm > >> @@ -24,6 +24,15 @@ config ARM_VEXPRESS_SPC_CPUFREQ > >> This add the CPUfreq driver support for Versatile Express > >> big.LITTLE platforms using SPC for power management. > >> > >> +config ARM_SCPI_CPUFREQ > >> + tristate "SCPI based CPUfreq driver" > >> + depends on ARM_BIG_LITTLE_CPUFREQ && ARM_SCPI_PROTOCOL > > > > And ARM_BIG_LITTLE_CPUFREQ depends on CONFIG_ARM, so we can't build this > > for arm64, which is the only platform (Juno) we have to run these > > patches on. > > Yes I know > > > Unless you're prepared for a horrid hack... > > https://github.com/ARM-software/linux/commit/b9ceaa0cbd7c57d57ee7e69146cc627697570f6e > > I need to check if it can be improved before I post on the list and > hence dropped it in the first version of this patch-set. > > > or a pair of less horrid ones... > > http://git.linaro.org/kernel/linux-linaro-tracking.git/commit/4b5dd8ff98613b7e90c8f3214522a00ab6900fe9 > > No not this one, this was already discussed long back I believe. > It doesn't make sense to add bl-switcher for ARM64 IMO. > > > http://git.linaro.org/kernel/linux-linaro-tracking.git/commit/8641dbfe253f6a9061742ca11f769fc1d82c2aaa > > > > Yes the Kconfig changes looks better than what I have now. > > > Any reason why the above two aren't suitable for mainline Linux? The > > second was actually committed then reverted because it broke arm64 > > builds, but the other patch fixes that. > > > Yes IMO since arm-big-little also supports multi-cluster cpufreq(yes I > know it can be merged into cpufreq-dt once we have OPPv2 bindings, but > until then), it should handle the config where CONFIG_BL_SWITCHER=n and > that's what I have attempted in my patch above. OK, that all makes sense, just wanted to make sure things didn't get overlooked, because having code that has no users in mainline seemed a bit odd.
On 01/05/15 15:12, Jon Medhurst (Tixy) wrote: > On Fri, 2015-05-01 at 14:32 +0100, Sudeep Holla wrote: >> >> On 01/05/15 14:19, Jon Medhurst (Tixy) wrote: >>> On Mon, 2015-04-27 at 12:40 +0100, Sudeep Holla wrote: >>>> On some ARM based systems, a separate Cortex-M based System Control >>>> Processor(SCP) provides the overall power, clock, reset and system >>>> control including CPU DVFS. SCPI Message Protocol is used to >>>> communicate with the SCPI. >>>> >>>> This patch adds a interface driver for adding OPPs and registering >>>> the arm_big_little cpufreq driver for such systems. >>>> >>>> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> >>>> Cc: Viresh Kumar <viresh.kumar@linaro.org> >>>> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> >>>> Cc: linux-pm@vger.kernel.org >>>> --- >>>> drivers/cpufreq/Kconfig.arm | 9 ++++ >>>> drivers/cpufreq/Makefile | 1 + >>>> drivers/cpufreq/scpi-cpufreq.c | 103 +++++++++++++++++++++++++++++++++++++++++ >>>> 3 files changed, 113 insertions(+) >>>> create mode 100644 drivers/cpufreq/scpi-cpufreq.c >>>> >>>> diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm >>>> index 4f3dbc8cf729..9e678bf1687c 100644 >>>> --- a/drivers/cpufreq/Kconfig.arm >>>> +++ b/drivers/cpufreq/Kconfig.arm >>>> @@ -24,6 +24,15 @@ config ARM_VEXPRESS_SPC_CPUFREQ >>>> This add the CPUfreq driver support for Versatile Express >>>> big.LITTLE platforms using SPC for power management. >>>> >>>> +config ARM_SCPI_CPUFREQ >>>> + tristate "SCPI based CPUfreq driver" >>>> + depends on ARM_BIG_LITTLE_CPUFREQ && ARM_SCPI_PROTOCOL >>> >>> And ARM_BIG_LITTLE_CPUFREQ depends on CONFIG_ARM, so we can't build this >>> for arm64, which is the only platform (Juno) we have to run these >>> patches on. >> >> Yes I know >> >>> Unless you're prepared for a horrid hack... >>> https://github.com/ARM-software/linux/commit/b9ceaa0cbd7c57d57ee7e69146cc627697570f6e >> >> I need to check if it can be improved before I post on the list and >> hence dropped it in the first version of this patch-set. >> >>> or a pair of less horrid ones... >>> http://git.linaro.org/kernel/linux-linaro-tracking.git/commit/4b5dd8ff98613b7e90c8f3214522a00ab6900fe9 >> >> No not this one, this was already discussed long back I believe. >> It doesn't make sense to add bl-switcher for ARM64 IMO. >> >>> http://git.linaro.org/kernel/linux-linaro-tracking.git/commit/8641dbfe253f6a9061742ca11f769fc1d82c2aaa >>> >> >> Yes the Kconfig changes looks better than what I have now. >> >>> Any reason why the above two aren't suitable for mainline Linux? The >>> second was actually committed then reverted because it broke arm64 >>> builds, but the other patch fixes that. >>> >> Yes IMO since arm-big-little also supports multi-cluster cpufreq(yes I >> know it can be merged into cpufreq-dt once we have OPPv2 bindings, but >> until then), it should handle the config where CONFIG_BL_SWITCHER=n and >> that's what I have attempted in my patch above. > > OK, that all makes sense, just wanted to make sure things didn't get > overlooked, because having code that has no users in mainline seemed a > bit odd. > No issues, it's better to have remainders like this :). I plan to post something in the next version. Regards, Sudeep -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, 2015-05-01 at 15:15 +0100, Sudeep Holla wrote: > No issues, it's better to have remainders like this :). I plan to post > something in the next version. Will that also include the other piece of the puzzle to get the big.LITTLE cpufreq driver running? ;-) ... https://github.com/ARM-software/linux/commit/29c33a5865437f0745e8e3a9beb5f82694257b4d With that, and device-tree updates [1], I've finally managed to get this patch series running on Juno with v4.1-rc1 and they pass some basic smoke testing.
On 01/05/15 18:10, Jon Medhurst (Tixy) wrote: > On Fri, 2015-05-01 at 15:15 +0100, Sudeep Holla wrote: >> No issues, it's better to have remainders like this :). I plan to post >> something in the next version. > > Will that also include the other piece of the puzzle to get the > big.LITTLE cpufreq driver running? ;-) ... > https://github.com/ARM-software/linux/commit/29c33a5865437f0745e8e3a9beb5f82694257b4d That is already posted separately[1] and acked-by Viresh. I am trying to put independent patches(not related to Juno/SCPI) separate so that they will be no dependency to merge that. Regards, Sudeep [1] https://lkml.org/lkml/2015/4/27/174 -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm index 4f3dbc8cf729..9e678bf1687c 100644 --- a/drivers/cpufreq/Kconfig.arm +++ b/drivers/cpufreq/Kconfig.arm @@ -24,6 +24,15 @@ config ARM_VEXPRESS_SPC_CPUFREQ This add the CPUfreq driver support for Versatile Express big.LITTLE platforms using SPC for power management. +config ARM_SCPI_CPUFREQ + tristate "SCPI based CPUfreq driver" + depends on ARM_BIG_LITTLE_CPUFREQ && ARM_SCPI_PROTOCOL + help + This add the CPUfreq driver support for ARM big.LITTLE platforms + using SCPI interface for CPU power management. + + This driver works only if firmware the supporting CPU DVFS adhere + to SCPI protocol. config ARM_EXYNOS_CPUFREQ tristate "SAMSUNG EXYNOS CPUfreq Driver" diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile index cdce92ae2e8b..02fc9f849d4b 100644 --- a/drivers/cpufreq/Makefile +++ b/drivers/cpufreq/Makefile @@ -79,6 +79,7 @@ obj-$(CONFIG_ARM_SA1110_CPUFREQ) += sa1110-cpufreq.o obj-$(CONFIG_ARM_SPEAR_CPUFREQ) += spear-cpufreq.o obj-$(CONFIG_ARM_TEGRA_CPUFREQ) += tegra-cpufreq.o obj-$(CONFIG_ARM_VEXPRESS_SPC_CPUFREQ) += vexpress-spc-cpufreq.o +obj-$(CONFIG_ARM_SCPI_CPUFREQ) += scpi-cpufreq.o ################################################################################## # PowerPC platform drivers diff --git a/drivers/cpufreq/scpi-cpufreq.c b/drivers/cpufreq/scpi-cpufreq.c new file mode 100644 index 000000000000..4c2c11a9dfc6 --- /dev/null +++ b/drivers/cpufreq/scpi-cpufreq.c @@ -0,0 +1,103 @@ +/* + * SCPI CPUFreq Interface driver + * + * It provides necessary ops to arm_big_little cpufreq driver. + * + * Copyright (C) 2015 ARM Ltd. + * Sudeep Holla <sudeep.holla@arm.com> + * + * 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. + * + * This program is distributed "as is" WITHOUT ANY WARRANTY of any + * kind, whether express or implied; without even the implied warranty + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/cpufreq.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/pm_opp.h> +#include <linux/scpi_protocol.h> +#include <linux/types.h> + +#include "arm_big_little.h" + +static struct scpi_ops *scpi_ops; + +static int scpi_init_opp_table(struct device *cpu_dev) +{ + u8 domain = topology_physical_package_id(cpu_dev->id); + struct scpi_dvfs_info *info; + struct scpi_opp *opp; + int idx, ret = 0; + + if ((dev_pm_opp_get_opp_count(cpu_dev)) > 0) + return 0; + info = scpi_ops->dvfs_get_info(domain); + if (IS_ERR(info)) + return PTR_ERR(info); + + opp = info->opps; + if (!opp) + return -EIO; + + for (idx = 0; idx < info->count; idx++, opp++) { + ret = dev_pm_opp_add(cpu_dev, opp->freq, opp->m_volt * 1000); + if (ret) { + dev_warn(cpu_dev, "failed to add opp %uHz %umV\n", + opp->freq, opp->m_volt); + return ret; + } + } + return ret; +} + +static int scpi_get_transition_latency(struct device *cpu_dev) +{ + u8 domain = topology_physical_package_id(cpu_dev->id); + struct scpi_dvfs_info *info; + + info = scpi_ops->dvfs_get_info(domain); + if (IS_ERR(info)) + return PTR_ERR(info); + + return info->latency; +} + +static struct cpufreq_arm_bL_ops scpi_cpufreq_ops = { + .name = "scpi", + .get_transition_latency = scpi_get_transition_latency, + .init_opp_table = scpi_init_opp_table, +}; + +static int scpi_cpufreq_probe(struct platform_device *pdev) +{ + scpi_ops = get_scpi_ops(); + if (!scpi_ops) + return -EIO; + + return bL_cpufreq_register(&scpi_cpufreq_ops); +} + +static int scpi_cpufreq_remove(struct platform_device *pdev) +{ + bL_cpufreq_unregister(&scpi_cpufreq_ops); + return 0; +} + +static struct platform_driver scpi_cpufreq_platdrv = { + .driver = { + .name = "scpi-cpufreq", + .owner = THIS_MODULE, + }, + .probe = scpi_cpufreq_probe, + .remove = scpi_cpufreq_remove, +}; +module_platform_driver(scpi_cpufreq_platdrv); + +MODULE_LICENSE("GPL");
On some ARM based systems, a separate Cortex-M based System Control Processor(SCP) provides the overall power, clock, reset and system control including CPU DVFS. SCPI Message Protocol is used to communicate with the SCPI. This patch adds a interface driver for adding OPPs and registering the arm_big_little cpufreq driver for such systems. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: linux-pm@vger.kernel.org --- drivers/cpufreq/Kconfig.arm | 9 ++++ drivers/cpufreq/Makefile | 1 + drivers/cpufreq/scpi-cpufreq.c | 103 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 113 insertions(+) create mode 100644 drivers/cpufreq/scpi-cpufreq.c