[PATCH] thermal: Add Intel PCH thermal driver

[Tushar Dave <tushar.n.dave@intel.com>]

This change adds a thermal driver for Wildcat Point platform controller
hub. This driver register PCH thermal sensor as a thermal zone and
associate critical and hot trips if present.

Signed-off-by: Tushar Dave <tushar.n.dave@intel.com>
Reviewed-by: Pandruvada, Srinivas <srinivas.pandruvada@intel.com>
---
 drivers/thermal/Kconfig             |   8 +
 drivers/thermal/Makefile            |   1 +
 drivers/thermal/intel_pch_thermal.c | 286 ++++++++++++++++++++++++++++++++++++
 3 files changed, 295 insertions(+)
 create mode 100644 drivers/thermal/intel_pch_thermal.c

diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index af40db0..7295512 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -285,6 +285,14 @@ config ACPI_THERMAL_REL
 	tristate
 	depends on ACPI
 
+config INTEL_PCH_THERMAL
+	tristate "Intel PCH Thermal Reporting Driver"
+	depends on X86 && PCI
+	help
+	  Enable this to support thermal reporting on certain intel PCHs.
+	  Thermal reporting device will provide temperature reading,
+	  programmable trip points and other information.
+
 menu "Texas Instruments thermal drivers"
 source "drivers/thermal/ti-soc-thermal/Kconfig"
 endmenu
diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
index fa0dc48..ce1b526 100644
--- a/drivers/thermal/Makefile
+++ b/drivers/thermal/Makefile
@@ -39,3 +39,4 @@ obj-$(CONFIG_TI_SOC_THERMAL)	+= ti-soc-thermal/
 obj-$(CONFIG_INT340X_THERMAL)  += int340x_thermal/
 obj-$(CONFIG_ST_THERMAL)	+= st/
 obj-$(CONFIG_TEGRA_SOCTHERM)	+= tegra_soctherm.o
+obj-$(CONFIG_INTEL_PCH_THERMAL) += intel_pch_thermal.o
diff --git a/drivers/thermal/intel_pch_thermal.c b/drivers/thermal/intel_pch_thermal.c
new file mode 100644
index 0000000..d9e07fd
--- /dev/null
+++ b/drivers/thermal/intel_pch_thermal.c
@@ -0,0 +1,286 @@
+/* intel_pch_thermal.c - Intel PCH Thermal driver
+ *
+ * Copyright (c) 2015, Intel Corporation.
+ *
+ * Authors:
+ *     Tushar Dave <tushar.n.dave@intel.com>
+ *
+ * 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/module.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/pci.h>
+#include <linux/thermal.h>
+
+/* Intel PCH thermal Device IDs */
+#define PCH_THERMAL_DID_WPT	0x9CA4 /* Wildcat Point */
+
+/* Wildcat Point-LP  PCH Thermal registers */
+#define WPT_TEMP	0x0000	/* Temperature */
+#define WPT_TSC	0x04	/* Thermal Sensor Control */
+#define WPT_TSS	0x06	/* Thermal Sensor Status */
+#define WPT_TSEL	0x08	/* Thermal Sensor Enable and Lock */
+#define WPT_TSREL	0x0A	/* Thermal Sensor Report Enable and Lock */
+#define WPT_TSMIC	0x0C	/* Thermal Sensor SMI Control */
+#define WPT_CTT	0x0010	/* Catastrophic Trip Point */
+#define WPT_TAHV	0x0014	/* Thermal Alert High Value */
+#define WPT_TALV	0x0018	/* Thermal Alert Low Value */
+#define WPT_TL		0x00000040	/* Throttle Value */
+#define WPT_PHL	0x0060	/* PCH Hot Level */
+#define WPT_PHLC	0x62	/* PHL Control */
+#define WPT_TAS	0x80	/* Thermal Alert Status */
+#define WPT_TSPIEN	0x82	/* PCI Interrupt Event Enables */
+#define WPT_TSGPEN	0x84	/* General Purpose Event Enables */
+
+/*  Wildcat Point-LP  PCH Thermal Register bit definitions */
+#define WPT_TEMP_TSR	0x00ff	/* Temp TS Reading */
+#define WPT_TSC_CPDE	0x01	/* Catastrophic Power-Down Enable */
+#define WPT_TSS_TSDSS	0x10	/* Thermal Sensor Dynamic Shutdown Status */
+#define WPT_TSS_GPES	0x08	/* GPE status */
+#define WPT_TSEL_ETS	0x01    /* Enable TS */
+#define WPT_TSEL_PLDB	0x80	/* TSEL Policy Lock-Down Bit */
+#define WPT_TL_TOL	0x000001FF	/* T0 Level */
+#define WPT_TL_T1L	0x1ff00000	/* T1 Level */
+#define WPT_TL_TTEN	0x20000000	/* TT Enable */
+
+char driver_name[] = "Intel PCH thermal driver";
+
+struct pch_thermal_device {
+	void __iomem *hw_base;
+	const struct pch_dev_ops *ops;
+	struct pci_dev *pdev;
+	struct thermal_zone_device *tzd;
+	int crt_trip_id;
+	unsigned long crt_temp;
+	int hot_trip_id;
+	unsigned long hot_temp;
+};
+
+static int pch_wpt_init(struct pch_thermal_device *ptd, int *nr_trips)
+{
+	u8 tsel;
+	u16 trip_temp;
+
+	*nr_trips = 0;
+
+	/* Check if BIOS has already enabled thermal sensor */
+	if (WPT_TSS_TSDSS & readb(ptd->hw_base + WPT_TSS))
+		goto read_trips;
+
+	tsel = readb(ptd->hw_base + WPT_TSEL);
+	/*
+	 * When TSEL's Policy Lock-Down bit is 1, TSEL become RO.
+	 * If so, thermal sensor cannot enable. Bail out.
+	 */
+	if (tsel & WPT_TSEL_PLDB) {
+		dev_err(&ptd->pdev->dev, "Sensor can't be enabled\n");
+		return -ENODEV;
+	}
+
+	writeb(tsel|WPT_TSEL_ETS, ptd->hw_base + WPT_TSEL);
+	if (!(WPT_TSS_TSDSS & readb(ptd->hw_base + WPT_TSS))) {
+		dev_err(&ptd->pdev->dev, "Sensor can't be enabled\n");
+		return -ENODEV;
+	}
+
+read_trips:
+	ptd->crt_trip_id = -1;
+	trip_temp = readw(ptd->hw_base + WPT_CTT);
+	trip_temp &= 0x1FF;
+	if (trip_temp) {
+		/* Resolution of 1/2 degree C and an offset of -50C */
+		ptd->crt_temp = trip_temp * 1000 / 2 - 50000;
+		ptd->crt_trip_id = 0;
+		++(*nr_trips);
+	}
+
+	ptd->hot_trip_id = -1;
+	trip_temp = readw(ptd->hw_base + WPT_PHL);
+	trip_temp &= 0x1FF;
+	if (trip_temp) {
+		/* Resolution of 1/2 degree C and an offset of -50C */
+		ptd->hot_temp = trip_temp * 1000 / 2 - 50000;
+		ptd->hot_trip_id = *nr_trips;
+		++(*nr_trips);
+	}
+
+	return 0;
+}
+
+static int pch_wpt_get_temp(struct pch_thermal_device *ptd,
+			    unsigned long *temp)
+{
+	u8 wpt_temp;
+
+	wpt_temp = WPT_TEMP_TSR & readl(ptd->hw_base + WPT_TEMP);
+
+	/* Resolution of 1/2 degree C and an offset of -50C */
+	*temp = (wpt_temp * 1000 / 2 - 50000);
+
+	return 0;
+}
+
+struct pch_dev_ops {
+	int (*hw_init)(struct pch_thermal_device *ptd, int *nr_trips);
+	int (*get_temp)(struct pch_thermal_device *ptd, unsigned long *temp);
+};
+
+
+/* dev ops for Wildcat Point */
+struct pch_dev_ops pch_dev_ops_wpt = {
+	.hw_init = pch_wpt_init,
+	.get_temp = pch_wpt_get_temp,
+};
+
+static int pch_thermal_get_temp(struct thermal_zone_device *tzd,
+				unsigned long *temp)
+{
+	struct pch_thermal_device *ptd = tzd->devdata;
+
+	return	ptd->ops->get_temp(ptd, temp);
+}
+
+static int pch_get_trip_type(struct thermal_zone_device *tzd, int trip,
+			     enum thermal_trip_type *type)
+{
+	struct pch_thermal_device *ptd = tzd->devdata;
+
+	if (ptd->crt_trip_id == trip)
+		*type = THERMAL_TRIP_CRITICAL;
+	else if (ptd->hot_trip_id == trip)
+		*type = THERMAL_TRIP_HOT;
+	else
+		return -EINVAL;
+
+	return 0;
+}
+
+static int pch_get_trip_temp(struct thermal_zone_device *tzd, int trip,
+			     unsigned long *temp)
+{
+	struct pch_thermal_device *ptd = tzd->devdata;
+
+	if (ptd->crt_trip_id == trip)
+		*temp = ptd->crt_temp;
+	else if (ptd->hot_trip_id == trip)
+		*temp = ptd->hot_temp;
+	else
+		return -EINVAL;
+
+	return 0;
+}
+
+static struct thermal_zone_device_ops tzd_ops = {
+	.get_temp = pch_thermal_get_temp,
+	.get_trip_type = pch_get_trip_type,
+	.get_trip_temp = pch_get_trip_temp,
+};
+
+
+static int intel_pch_thermal_probe(struct pci_dev *pdev,
+				   const struct pci_device_id *id)
+{
+	struct pch_thermal_device *ptd;
+	int err;
+	int nr_trips;
+	char *dev_name;
+
+	ptd = devm_kzalloc(&pdev->dev, sizeof(*ptd), GFP_KERNEL);
+	if (!ptd)
+		return -ENOMEM;
+
+	switch (pdev->device) {
+	case PCH_THERMAL_DID_WPT:
+		ptd->ops = &pch_dev_ops_wpt;
+		dev_name = "pch_wildcat_point";
+		break;
+	default:
+		dev_err(&pdev->dev, "unknown pch thermal device\n");
+		return -ENODEV;
+	}
+
+	pci_set_drvdata(pdev, ptd);
+	ptd->pdev = pdev;
+
+	err = pci_enable_device(pdev);
+	if (err) {
+		dev_err(&pdev->dev, "failed to enable pci device\n");
+		return err;
+	}
+
+	err = pci_request_regions(pdev, driver_name);
+	if (err) {
+		dev_err(&pdev->dev, "failed to request pci region\n");
+		goto error_disable;
+	}
+
+	ptd->hw_base = pci_ioremap_bar(pdev, 0);
+	if (!ptd->hw_base) {
+		err = -ENOMEM;
+		dev_err(&pdev->dev, "failed to map mem base\n");
+		goto error_release;
+	}
+
+	err = ptd->ops->hw_init(ptd, &nr_trips);
+	if (err)
+		goto error_cleanup;
+
+	ptd->tzd = thermal_zone_device_register(dev_name, nr_trips, 0, ptd,
+						&tzd_ops, NULL, 0, 0);
+	if (IS_ERR(ptd->tzd)) {
+		dev_err(&pdev->dev, "Failed to register thermal zone %s\n",
+			dev_name);
+		err = PTR_ERR(ptd->tzd);
+		goto error_cleanup;
+	}
+
+	return 0;
+
+error_cleanup:
+	iounmap(ptd->hw_base);
+error_release:
+	pci_release_regions(pdev);
+error_disable:
+	pci_disable_device(pdev);
+	dev_err(&pdev->dev, "pci device failed to probe\n");
+	return err;
+}
+
+static void intel_pch_thermal_remove(struct pci_dev *pdev)
+{
+	struct pch_thermal_device *ptd = pci_get_drvdata(pdev);
+
+	thermal_zone_device_unregister(ptd->tzd);
+	iounmap(ptd->hw_base);
+	pci_set_drvdata(pdev, NULL);
+	pci_release_region(pdev, 0);
+	pci_disable_device(pdev);
+}
+
+static struct pci_device_id intel_pch_thermal_id[] = {
+	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCH_THERMAL_DID_WPT) },
+	{ 0, },
+};
+MODULE_DEVICE_TABLE(pci, intel_pch_thermal_id);
+
+static struct pci_driver intel_pch_thermal_driver = {
+	.name		= "intel_pch_thermal",
+	.id_table	= intel_pch_thermal_id,
+	.probe		= intel_pch_thermal_probe,
+	.remove		= intel_pch_thermal_remove,
+};
+
+module_pci_driver(intel_pch_thermal_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Intel PCH Thermal driver");
-- 
1.9.1