thermal: Add Intel PCH thermal driver

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>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

3 files changed, 295 insertions, 0 deletions

diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index 118938ee8552..039004400987 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -340,6 +340,14 @@ 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 535dfee1496f..26f160809959 100644
--- a/drivers/thermal/Makefile
+++ b/drivers/thermal/Makefile
@@ -41,6 +41,7 @@ obj-$(CONFIG_INTEL_SOC_DTS_THERMAL)	+= intel_soc_dts_thermal.o
 obj-$(CONFIG_INTEL_QUARK_DTS_THERMAL)   += intel_quark_dts_thermal.o
 obj-$(CONFIG_TI_SOC_THERMAL)    += ti-soc-thermal/
 obj-$(CONFIG_INT340X_THERMAL)  += int340x_thermal/
+obj-$(CONFIG_INTEL_PCH_THERMAL) += intel_pch_thermal.o
 obj-$(CONFIG_ST_THERMAL)        += st/
 obj-$(CONFIG_TEGRA_SOCTHERM)    += tegra_soctherm.o
 obj-$(CONFIG_HISI_THERMAL)     += hisi_thermal.o
diff --git a/drivers/thermal/intel_pch_thermal.c b/drivers/thermal/intel_pch_thermal.c
new file mode 100644
index 000000000000..1650a62484bd
--- /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 */
+
+static 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 */
+static 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");