diff options
Diffstat (limited to 'kernel/drivers/hwtracing/intel_th/pti.c')
| -rw-r--r-- | kernel/drivers/hwtracing/intel_th/pti.c | 252 |
1 files changed, 252 insertions, 0 deletions
diff --git a/kernel/drivers/hwtracing/intel_th/pti.c b/kernel/drivers/hwtracing/intel_th/pti.c new file mode 100644 index 000000000..57cbfdcc7 --- /dev/null +++ b/kernel/drivers/hwtracing/intel_th/pti.c @@ -0,0 +1,252 @@ +/* + * Intel(R) Trace Hub PTI output driver + * + * Copyright (C) 2014-2015 Intel Corporation. + * + * 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. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/types.h> +#include <linux/module.h> +#include <linux/device.h> +#include <linux/sizes.h> +#include <linux/printk.h> +#include <linux/slab.h> +#include <linux/mm.h> +#include <linux/io.h> + +#include "intel_th.h" +#include "pti.h" + +struct pti_device { + void __iomem *base; + struct intel_th_device *thdev; + unsigned int mode; + unsigned int freeclk; + unsigned int clkdiv; + unsigned int patgen; +}; + +/* map PTI widths to MODE settings of PTI_CTL register */ +static const unsigned int pti_mode[] = { + 0, 4, 8, 0, 12, 0, 0, 0, 16, 0, 0, 0, 0, 0, 0, 0, +}; + +static int pti_width_mode(unsigned int width) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(pti_mode); i++) + if (pti_mode[i] == width) + return i; + + return -EINVAL; +} + +static ssize_t mode_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct pti_device *pti = dev_get_drvdata(dev); + + return scnprintf(buf, PAGE_SIZE, "%d\n", pti_mode[pti->mode]); +} + +static ssize_t mode_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t size) +{ + struct pti_device *pti = dev_get_drvdata(dev); + unsigned long val; + int ret; + + ret = kstrtoul(buf, 10, &val); + if (ret) + return ret; + + ret = pti_width_mode(val); + if (ret < 0) + return ret; + + pti->mode = ret; + + return size; +} + +static DEVICE_ATTR_RW(mode); + +static ssize_t +freerunning_clock_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct pti_device *pti = dev_get_drvdata(dev); + + return scnprintf(buf, PAGE_SIZE, "%d\n", pti->freeclk); +} + +static ssize_t +freerunning_clock_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t size) +{ + struct pti_device *pti = dev_get_drvdata(dev); + unsigned long val; + int ret; + + ret = kstrtoul(buf, 10, &val); + if (ret) + return ret; + + pti->freeclk = !!val; + + return size; +} + +static DEVICE_ATTR_RW(freerunning_clock); + +static ssize_t +clock_divider_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct pti_device *pti = dev_get_drvdata(dev); + + return scnprintf(buf, PAGE_SIZE, "%d\n", 1u << pti->clkdiv); +} + +static ssize_t +clock_divider_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t size) +{ + struct pti_device *pti = dev_get_drvdata(dev); + unsigned long val; + int ret; + + ret = kstrtoul(buf, 10, &val); + if (ret) + return ret; + + if (!is_power_of_2(val) || val > 8 || !val) + return -EINVAL; + + pti->clkdiv = val; + + return size; +} + +static DEVICE_ATTR_RW(clock_divider); + +static struct attribute *pti_output_attrs[] = { + &dev_attr_mode.attr, + &dev_attr_freerunning_clock.attr, + &dev_attr_clock_divider.attr, + NULL, +}; + +static struct attribute_group pti_output_group = { + .attrs = pti_output_attrs, +}; + +static int intel_th_pti_activate(struct intel_th_device *thdev) +{ + struct pti_device *pti = dev_get_drvdata(&thdev->dev); + u32 ctl = PTI_EN; + + if (pti->patgen) + ctl |= pti->patgen << __ffs(PTI_PATGENMODE); + if (pti->freeclk) + ctl |= PTI_FCEN; + ctl |= pti->mode << __ffs(PTI_MODE); + ctl |= pti->clkdiv << __ffs(PTI_CLKDIV); + + iowrite32(ctl, pti->base + REG_PTI_CTL); + + intel_th_trace_enable(thdev); + + return 0; +} + +static void intel_th_pti_deactivate(struct intel_th_device *thdev) +{ + struct pti_device *pti = dev_get_drvdata(&thdev->dev); + + intel_th_trace_disable(thdev); + + iowrite32(0, pti->base + REG_PTI_CTL); +} + +static void read_hw_config(struct pti_device *pti) +{ + u32 ctl = ioread32(pti->base + REG_PTI_CTL); + + pti->mode = (ctl & PTI_MODE) >> __ffs(PTI_MODE); + pti->clkdiv = (ctl & PTI_CLKDIV) >> __ffs(PTI_CLKDIV); + pti->freeclk = !!(ctl & PTI_FCEN); + + if (!pti_mode[pti->mode]) + pti->mode = pti_width_mode(4); + if (!pti->clkdiv) + pti->clkdiv = 1; +} + +static int intel_th_pti_probe(struct intel_th_device *thdev) +{ + struct device *dev = &thdev->dev; + struct resource *res; + struct pti_device *pti; + void __iomem *base; + int ret; + + res = intel_th_device_get_resource(thdev, IORESOURCE_MEM, 0); + if (!res) + return -ENODEV; + + base = devm_ioremap(dev, res->start, resource_size(res)); + if (!base) + return -ENOMEM; + + pti = devm_kzalloc(dev, sizeof(*pti), GFP_KERNEL); + if (!pti) + return -ENOMEM; + + pti->thdev = thdev; + pti->base = base; + + read_hw_config(pti); + + ret = sysfs_create_group(&dev->kobj, &pti_output_group); + if (ret) + return ret; + + dev_set_drvdata(dev, pti); + + return 0; +} + +static void intel_th_pti_remove(struct intel_th_device *thdev) +{ +} + +static struct intel_th_driver intel_th_pti_driver = { + .probe = intel_th_pti_probe, + .remove = intel_th_pti_remove, + .activate = intel_th_pti_activate, + .deactivate = intel_th_pti_deactivate, + .driver = { + .name = "pti", + .owner = THIS_MODULE, + }, +}; + +module_driver(intel_th_pti_driver, + intel_th_driver_register, + intel_th_driver_unregister); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("Intel(R) Trace Hub PTI output driver"); +MODULE_AUTHOR("Alexander Shishkin <alexander.shishkin@linux.intel.com>"); |