intel_th: Add PTI output driver
authorAlexander Shishkin <alexander.shishkin@linux.intel.com>
Tue, 22 Sep 2015 12:47:19 +0000 (15:47 +0300)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sun, 4 Oct 2015 19:28:58 +0000 (20:28 +0100)
Parallel Trace Interface (PTI) unit is a trace output device that sends
data over a PTI port.

The driver provides interfaces to configure bus width, bus clock divider
and mode. Tracing is enabled via output device's "active" attribute.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Documentation/ABI/testing/sysfs-bus-intel_th-devices-pti [new file with mode: 0644]
drivers/hwtracing/intel_th/Kconfig
drivers/hwtracing/intel_th/Makefile
drivers/hwtracing/intel_th/pti.c [new file with mode: 0644]
drivers/hwtracing/intel_th/pti.h [new file with mode: 0644]

diff --git a/Documentation/ABI/testing/sysfs-bus-intel_th-devices-pti b/Documentation/ABI/testing/sysfs-bus-intel_th-devices-pti
new file mode 100644 (file)
index 0000000..df0b24f
--- /dev/null
@@ -0,0 +1,24 @@
+What:          /sys/bus/intel_th/devices/<intel_th_id>-pti/mode
+Date:          June 2015
+KernelVersion: 4.3
+Contact:       Alexander Shishkin <alexander.shishkin@linux.intel.com>
+Description:   (RW) Configure PTI output width. Currently supported values
+               are 4, 8, 12, 16.
+
+What:          /sys/bus/intel_th/devices/<intel_th_id>-pti/freerunning_clock
+Date:          June 2015
+KernelVersion: 4.3
+Contact:       Alexander Shishkin <alexander.shishkin@linux.intel.com>
+Description:   (RW) 0: PTI trace clock acts as a strobe which only toggles
+               when there is trace data to send. 1: PTI trace clock is a
+               free-running clock.
+
+What:          /sys/bus/intel_th/devices/<intel_th_id>-pti/clock_divider
+Date:          June 2015
+KernelVersion: 4.3
+Contact:       Alexander Shishkin <alexander.shishkin@linux.intel.com>
+Description:   (RW) Configure PTI port clock divider:
+                - 0: Intel TH clock rate,
+                - 1: 1/2 Intel TH clock rate,
+                - 2: 1/4 Intel TH clock rate,
+                - 3: 1/8 Intel TH clock rate.
index d9a1217e27bf7600ad27ab264a76cce0b1322383..b7a9073d968b57bd8f2b7f5c3d0fd92db23a1301 100644 (file)
@@ -54,6 +54,15 @@ config INTEL_TH_MSU
 
          Say Y here to enable MSU output device for Intel TH.
 
+config INTEL_TH_PTI
+       tristate "Intel(R) Trace Hub PTI output"
+       help
+         Parallel Trace Interface unit (PTI) is a trace output device
+         of Intel TH architecture that facilitates STP trace output via
+         a PTI port.
+
+         Say Y to enable PTI output of Intel TH data.
+
 config INTEL_TH_DEBUG
        bool "Intel(R) Trace Hub debugging"
        depends on DEBUG_FS
index 4636757df2a1e20a6c790942c252d421af04f0eb..81d42fe918f77b4604ed607575147297a21bd8a4 100644 (file)
@@ -13,3 +13,6 @@ intel_th_sth-y                        := sth.o
 
 obj-$(CONFIG_INTEL_TH_MSU)     += intel_th_msu.o
 intel_th_msu-y                 := msu.o
+
+obj-$(CONFIG_INTEL_TH_PTI)     += intel_th_pti.o
+intel_th_pti-y                 := pti.o
diff --git a/drivers/hwtracing/intel_th/pti.c b/drivers/hwtracing/intel_th/pti.c
new file mode 100644 (file)
index 0000000..1e3bbc8
--- /dev/null
@@ -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 (IS_ERR(base))
+               return PTR_ERR(base);
+
+       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>");
diff --git a/drivers/hwtracing/intel_th/pti.h b/drivers/hwtracing/intel_th/pti.h
new file mode 100644 (file)
index 0000000..20883f5
--- /dev/null
@@ -0,0 +1,29 @@
+/*
+ * Intel(R) Trace Hub PTI output data structures
+ *
+ * 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.
+ */
+
+#ifndef __INTEL_TH_STH_H__
+#define __INTEL_TH_STH_H__
+
+enum {
+       REG_PTI_CTL     = 0x1c00,
+};
+
+#define PTI_EN         BIT(0)
+#define PTI_FCEN       BIT(1)
+#define PTI_MODE       0xf0
+#define PTI_CLKDIV     0x000f0000
+#define PTI_PATGENMODE 0x00f00000
+
+#endif /* __INTEL_TH_STH_H__ */