On Thu, 2016-05-26 at 14:41 +0530, Rajneesh Bhardwaj wrote: > This patch adds the Power Management Controller driver as a PCI driver > for Intel Core SoC architecture. > > This driver can utilize debugging capabilities and supported features > as exposed by the Power Management Controller. > > Please refer to the below specification for more details on PMC > features. > http://www.intel.in/content/www/in/en/chipsets/100-series-chipset-data > sheet-vol-2.html > > The current version of this driver exposes SLP_S0_RESIDENCY counter. > This counter can be used for detecting fragile SLP_S0 signal related > failures and take corrective actions when PCH SLP_S0 signal is not > asserted after kernel freeze as part of suspend to idle flow > (echo freeze > /sys/power/state). > > Intel Platform Controller Hub (PCH) asserts SLP_S0 signal when it > detects favorable conditions to enter its low power mode. As a > pre-requisite the SoC should be in deepest possible Package C-State > and devices should be in low power mode. For example, on Skylake SoC > the deepest Package C-State is Package C10 or PC10. Suspend to idle > flow generally leads to PC10 state but PC10 state may not be > sufficient > for realizing the platform wide power potential which SLP_S0 signal > assertion can provide. > > SLP_S0 signal is often connected to the Embedded Controller (EC) and > the > Power Management IC (PMIC) for other platform power management related > optimizations. > > In general, SLP_S0 assertion == PC10 + PCH low power mode + ModPhy > Lanes > power gated + PLL Idle. > > As part of this driver, a mechanism to read the SLP_S0_RESIDENCY is > exposed > as an API and also debugfs features are added to indicate SLP_S0 > signal > assertion residency in microseconds. > > echo freeze > /sys/power/state > wake the system > cat /sys/kernel/debug/pmc_core/slp_s0_residency_usec > > Signed-off-by: Rajneesh Bhardwaj <rajneesh.bhardwaj@xxxxxxxxx> > Signed-off-by: Vishwanath Somayaji <vishwanath.somayaji@xxxxxxxxx> Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> > --- > Changes in v7: > * Using builtin_pci_driver instead of device_initcall to fix build > warning > * Deleted .remove line from struct intel_pmc_core_driver > > Changes in v6: > * Removed module specific code: > - removed module.h, .remove callback. > - replaced module_pci_driver with device_initcall. > - removed MODULE_* > * Address style related review comments. > * Updated Authors, MAINTAINERS. > * Removed unused #define from intel_pmc_core.h: > - SPT_PMC_REG_BIT_WIDTH > > Changes in v5: > * Addressed generic review comments for v4. > * Added generic read function "pmc_core_reg_read". > * Split the header file into two: > - arch/x86/include/asm/pmc_core.h => exposes API. > - driver/platform/x86/intel_pmc_core.h => used by the driver. > * Updated signature for intel_pmc_slp_s0_counter_read as slp_s0 > counter is a 32 bit counter. > * Updated SOB, Authors and MAINTAINERS. > * Using managed APIs: > - pcim_enable_device > - devm_ioremap_nocache > * Updated probe and remove code. > > Changes in v4: > * Moved the header file to drivers/platform/x86 directory. > * Updated the same in MAINTAINERS. > * Removed 'default y' option from Kconfig. > * Introduced static inline dummy functions for debugfs register > and unregister case when CONFIG_DEBUG_FS is not set. Removed > #if IS_ENABLED(CONFIG_DEBUG_FS) check from .probe and .remove > calls. > * Add CC to LKML (linux-kernel@xxxxxxxxxxxxxxx) > * Earlier review comments till v3 are available at: > - http://www.spinics.net/lists/platform-driver-x86/msg08790.html > - http://www.spinics.net/lists/platform-driver-x86/msg08759.html > - http://www.spinics.net/lists/platform-driver-x86/msg08742.html > > Changes in v3: > * Updated the commit message, added reference to the chipset > datasheet. > * Renamed the header file to intel_pmc_core.h for consistency. > * Added All rights reserved notification after the Copyright message. > * Improved variable names in the header file. Added SPT prefix. > * Fixed kernel-doc related whitespace and comma issues for struct > pmc_dev. > * Changed feature_available to bool has_slp_s0_res. > * Enhanced the Kconfig description as per the review suggestions. > * Added error propagating logic to pmc_core_dev_state_show. > * Streamlined intel_pmc_slp_s0_counter_read as per the review > comments. > * Streamlined the use of #if IS_ENABLED(CONFIG_DEBUG_FS) while > registering > debugfs in the probe call. > * Removed the *duplicate definition* of pmc_core_debugfs_register. > * Added MAINTAINERS related changes. > * Checkpatch warning due to long URL name in the commit message. > > Changes in v2: > * Fixed inconsistent spaces in the header file. > * Updated commit message. > * Enhanced acronym SKL CPU to Skylake CPUID Signature. > * Put error check on pci_read_config_dword in probe function. > * Changed goto label (disable) to disable_pci. > * Changed x86_match_cpu error handling for consistency. > > MAINTAINERS | 8 ++ > arch/x86/include/asm/pmc_core.h | 27 +++++ > drivers/platform/x86/Kconfig | 12 ++ > drivers/platform/x86/Makefile | 1 + > drivers/platform/x86/intel_pmc_core.c | 200 > ++++++++++++++++++++++++++++++++++ > drivers/platform/x86/intel_pmc_core.h | 51 +++++++++ > 6 files changed, 299 insertions(+) > create mode 100644 arch/x86/include/asm/pmc_core.h > create mode 100644 drivers/platform/x86/intel_pmc_core.c > create mode 100644 drivers/platform/x86/intel_pmc_core.h > > diff --git a/MAINTAINERS b/MAINTAINERS > index 3302006..db18359 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -6096,6 +6096,14 @@ S: Maintained > F: arch/x86/include/asm/intel_telemetry.h > F: drivers/platform/x86/intel_telemetry* > > +INTEL PMC CORE DRIVER > +M: Rajneesh Bhardwaj <rajneesh.bhardwaj@xxxxxxxxx> > +M: Vishwanath Somayaji <vishwanath.somayaji@xxxxxxxxx> > +L: platform-driver-x86@xxxxxxxxxxxxxxx > +S: Maintained > +F: arch/x86/include/asm/pmc_core.h > +F: drivers/platform/x86/intel_pmc_core* > + > IOC3 ETHERNET DRIVER > M: Ralf Baechle <ralf@xxxxxxxxxxxxxx> > L: linux-mips@xxxxxxxxxxxxxx > diff --git a/arch/x86/include/asm/pmc_core.h > b/arch/x86/include/asm/pmc_core.h > new file mode 100644 > index 0000000..d4855f1 > --- /dev/null > +++ b/arch/x86/include/asm/pmc_core.h > @@ -0,0 +1,27 @@ > +/* > + * Intel Core SoC Power Management Controller Header File > + * > + * Copyright (c) 2016, Intel Corporation. > + * All Rights Reserved. > + * > + * Authors: Rajneesh Bhardwaj <rajneesh.bhardwaj@xxxxxxxxx> > + * Vishwanath Somayaji <vishwanath.somayaji@xxxxxxxxx> > + * > + * This program is free software; you can redistribute it and/or > modify it > + * under the terms and conditions of the GNU General Public License, > + * version 2, as published by the Free Software Foundation. > + * > + * This program is distributed in the hope it will be useful, but > WITHOUT > + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY > or > + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public > License for > + * more details. > + * > + */ > + > +#ifndef _ASM_PMC_CORE_H > +#define _ASM_PMC_CORE_H > + > +/* API to read SLP_S0_RESIDENCY counter */ > +int intel_pmc_slp_s0_counter_read(u32 *data); > + > +#endif /* _ASM_PMC_CORE_H */ > diff --git a/drivers/platform/x86/Kconfig > b/drivers/platform/x86/Kconfig > index ed2004b..c06bb85 100644 > --- a/drivers/platform/x86/Kconfig > +++ b/drivers/platform/x86/Kconfig > @@ -846,6 +846,18 @@ config INTEL_IMR > > If you are running on a Galileo/Quark say Y here. > > +config INTEL_PMC_CORE > + bool "Intel PMC Core driver" > + depends on X86 && PCI > + ---help--- > + The Intel Platform Controller Hub for Intel Core SoCs > provides access > + to Power Management Controller registers via a PCI > interface. This > + driver can utilize debugging capabilities and supported > features as > + exposed by the Power Management Controller. > + > + Supported features: > + - SLP_S0_RESIDENCY counter. > + > config IBM_RTL > tristate "Device driver to enable PRTL support" > depends on X86 && PCI > diff --git a/drivers/platform/x86/Makefile > b/drivers/platform/x86/Makefile > index 448443c..9b11b40 100644 > --- a/drivers/platform/x86/Makefile > +++ b/drivers/platform/x86/Makefile > @@ -69,3 +69,4 @@ obj-$(CONFIG_INTEL_PUNIT_IPC) += intel_punit_ipc.o > obj-$(CONFIG_INTEL_TELEMETRY) += intel_telemetry_core.o \ > intel_telemetry_pltdrv.o \ > intel_telemetry_debugfs.o > +obj-$(CONFIG_INTEL_PMC_CORE) += intel_pmc_core.o > diff --git a/drivers/platform/x86/intel_pmc_core.c > b/drivers/platform/x86/intel_pmc_core.c > new file mode 100644 > index 0000000..2776bec > --- /dev/null > +++ b/drivers/platform/x86/intel_pmc_core.c > @@ -0,0 +1,200 @@ > +/* > + * Intel Core SoC Power Management Controller Driver > + * > + * Copyright (c) 2016, Intel Corporation. > + * All Rights Reserved. > + * > + * Authors: Rajneesh Bhardwaj <rajneesh.bhardwaj@xxxxxxxxx> > + * Vishwanath Somayaji <vishwanath.somayaji@xxxxxxxxx> > + * > + * This program is free software; you can redistribute it and/or > modify it > + * under the terms and conditions of the GNU General Public License, > + * version 2, as published by the Free Software Foundation. > + * > + * This program is distributed in the hope it will be useful, but > WITHOUT > + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY > or > + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public > License for > + * more details. > + * > + */ > + > +#include <linux/debugfs.h> > +#include <linux/device.h> > +#include <linux/init.h> > +#include <linux/io.h> > +#include <linux/pci.h> > +#include <linux/seq_file.h> > + > +#include <asm/cpu_device_id.h> > +#include <asm/pmc_core.h> > + > +#include "intel_pmc_core.h" > + > +static struct pmc_dev pmc; > + > +static const struct pci_device_id pmc_pci_ids[] = { > + { PCI_VDEVICE(INTEL, SPT_PMC_PCI_DEVICE_ID), > (kernel_ulong_t)NULL }, > + { 0, }, > +}; > + > +static inline u32 pmc_core_reg_read(struct pmc_dev *pmcdev, int > reg_offset) > +{ > + return readl(pmcdev->regbase + reg_offset); > +} > + > +static inline u32 pmc_core_adjust_slp_s0_step(u32 value) > +{ > + return value * SPT_PMC_SLP_S0_RES_COUNTER_STEP; > +} > + > +/** > + * intel_pmc_slp_s0_counter_read() - Read SLP_S0 residency. > + * @data: Out param that contains current SLP_S0 count. > + * > + * This API currently supports Intel Skylake SoC and Sunrise > + * Point Platform Controller Hub. Future platform support > + * should be added for platforms that support low power modes > + * beyond Package C10 state. > + * > + * SLP_S0_RESIDENCY counter counts in 100 us granularity per > + * step hence function populates the multiplied value in out > + * parameter @data. > + * > + * Return: an error code or 0 on success. > + */ > +int intel_pmc_slp_s0_counter_read(u32 *data) > +{ > + struct pmc_dev *pmcdev = &pmc; > + u32 value; > + > + if (!pmcdev->has_slp_s0_res) > + return -EACCES; > + > + value = pmc_core_reg_read(pmcdev, > SPT_PMC_SLP_S0_RES_COUNTER_OFFSET); > + *data = pmc_core_adjust_slp_s0_step(value); > + > + return 0; > +} > +EXPORT_SYMBOL_GPL(intel_pmc_slp_s0_counter_read); > + > +#if IS_ENABLED(CONFIG_DEBUG_FS) > +static int pmc_core_dev_state_show(struct seq_file *s, void *unused) > +{ > + struct pmc_dev *pmcdev = s->private; > + u32 counter_val; > + > + counter_val = pmc_core_reg_read(pmcdev, > + SPT_PMC_SLP_S0_RES_COUNTER_OF > FSET); > + seq_printf(s, "%u\n", > pmc_core_adjust_slp_s0_step(counter_val)); > + > + return 0; > +} > + > +static int pmc_core_dev_state_open(struct inode *inode, struct file > *file) > +{ > + return single_open(file, pmc_core_dev_state_show, inode- > >i_private); > +} > + > +static const struct file_operations pmc_core_dev_state_ops = { > + .open = pmc_core_dev_state_open, > + .read = seq_read, > + .llseek = seq_lseek, > + .release = single_release, > +}; > + > +static void pmc_core_dbgfs_unregister(struct pmc_dev *pmcdev) > +{ > + debugfs_remove_recursive(pmcdev->dbgfs_dir); > +} > + > +static int pmc_core_dbgfs_register(struct pmc_dev *pmcdev) > +{ > + struct dentry *dir, *file; > + > + dir = debugfs_create_dir("pmc_core", NULL); > + if (!dir) > + return -ENOMEM; > + > + pmcdev->dbgfs_dir = dir; > + file = debugfs_create_file("slp_s0_residency_usec", S_IFREG | > S_IRUGO, > + dir, pmcdev, > &pmc_core_dev_state_ops); > + > + if (!file) { > + pmc_core_dbgfs_unregister(pmcdev); > + return -ENODEV; > + } > + > + return 0; > +} > +#else > +static inline int pmc_core_dbgfs_register(struct pmc_dev *pmcdev) > +{ > + return 0; > +} > + > +static inline void pmc_core_dbgfs_unregister(struct pmc_dev *pmcdev) > +{ > +} > +#endif /* CONFIG_DEBUG_FS */ > + > +static const struct x86_cpu_id intel_pmc_core_ids[] = { > + { X86_VENDOR_INTEL, 6, 0x4e, X86_FEATURE_MWAIT, > + (kernel_ulong_t)NULL}, /* Skylake CPUID Signature */ > + { X86_VENDOR_INTEL, 6, 0x5e, X86_FEATURE_MWAIT, > + (kernel_ulong_t)NULL}, /* Skylake CPUID Signature */ > + {} > +}; > + > +static int pmc_core_probe(struct pci_dev *dev, const struct > pci_device_id *id) > +{ > + struct device *ptr_dev = &dev->dev; > + struct pmc_dev *pmcdev = &pmc; > + const struct x86_cpu_id *cpu_id; > + int err; > + > + cpu_id = x86_match_cpu(intel_pmc_core_ids); > + if (!cpu_id) { > + dev_dbg(&dev->dev, "PMC Core: cpuid mismatch.\n"); > + return -EINVAL; > + } > + > + err = pcim_enable_device(dev); > + if (err < 0) { > + dev_dbg(&dev->dev, "PMC Core: failed to enable Power > Management Controller.\n"); > + return err; > + } > + > + err = pci_read_config_dword(dev, > + SPT_PMC_BASE_ADDR_OFFSET, > + &pmcdev->base_addr); > + if (err < 0) { > + dev_dbg(&dev->dev, "PMC Core: failed to read PCI > config space.\n"); > + return err; > + } > + dev_dbg(&dev->dev, "PMC Core: PWRMBASE is %#x\n", pmcdev- > >base_addr); > + > + pmcdev->regbase = devm_ioremap_nocache(ptr_dev, > + pmcdev->base_addr, > + SPT_PMC_MMIO_REG_LEN); > + if (!pmcdev->regbase) { > + dev_dbg(&dev->dev, "PMC Core: ioremap failed.\n"); > + return -ENOMEM; > + } > + > + err = pmc_core_dbgfs_register(pmcdev); > + if (err < 0) { > + dev_err(&dev->dev, "PMC Core: debugfs register > failed.\n"); > + return err; > + } > + > + pmc.has_slp_s0_res = true; > + return 0; > +} > + > +static struct pci_driver intel_pmc_core_driver = { > + .name = "intel_pmc_core", > + .id_table = pmc_pci_ids, > + .probe = pmc_core_probe, > +}; > + > +builtin_pci_driver(intel_pmc_core_driver); > diff --git a/drivers/platform/x86/intel_pmc_core.h > b/drivers/platform/x86/intel_pmc_core.h > new file mode 100644 > index 0000000..a9dadaf > --- /dev/null > +++ b/drivers/platform/x86/intel_pmc_core.h > @@ -0,0 +1,51 @@ > +/* > + * Intel Core SoC Power Management Controller Header File > + * > + * Copyright (c) 2016, Intel Corporation. > + * All Rights Reserved. > + * > + * Authors: Rajneesh Bhardwaj <rajneesh.bhardwaj@xxxxxxxxx> > + * Vishwanath Somayaji <vishwanath.somayaji@xxxxxxxxx> > + * > + * This program is free software; you can redistribute it and/or > modify it > + * under the terms and conditions of the GNU General Public License, > + * version 2, as published by the Free Software Foundation. > + * > + * This program is distributed in the hope it will be useful, but > WITHOUT > + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY > or > + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public > License for > + * more details. > + * > + */ > + > +#ifndef PMC_CORE_H > +#define PMC_CORE_H > + > +/* Sunrise Point Power Management Controller PCI Device ID */ > +#define SPT_PMC_PCI_DEVICE_ID 0x9d21 > +#define SPT_PMC_BASE_ADDR_OFFSET 0x48 > +#define SPT_PMC_SLP_S0_RES_COUNTER_OFFSET 0x13c > +#define SPT_PMC_MMIO_REG_LEN 0x100 > +#define SPT_PMC_SLP_S0_RES_COUNTER_STEP 0x64 > + > +/** > + * struct pmc_dev - pmc device structure > + * @base_addr: comtains pmc base address > + * @regbase: pointer to io-remapped memory location > + * @dbgfs_dir: path to debug fs interface > + * @feature_available: flag to indicate whether > + * the feature is available > + * on a particular platform or not. > + * > + * pmc_dev contains info about power management controller device. > + */ > +struct pmc_dev { > + u32 base_addr; > + void __iomem *regbase; > +#if IS_ENABLED(CONFIG_DEBUG_FS) > + struct dentry *dbgfs_dir; > +#endif /* CONFIG_DEBUG_FS */ > + bool has_slp_s0_res; > +}; > + > +#endif /* PMC_CORE_H */ -- Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> Intel Finland Oy -- To unsubscribe from this list: send the line "unsubscribe platform-driver-x86" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
