thermal/broadcom/ns-thermal.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Copyright (C) 2017 Rafał Miłecki <rafal@milecki.pl>
0004  */
0005
0006 #include <linux/module.h>
0007 #include <linux/of_address.h>
0008 #include <linux/platform_device.h>
0009 #include <linux/thermal.h>
0010
0011 #define PVTMON_CONTROL0                 0x00
0012 #define PVTMON_CONTROL0_SEL_MASK            0x0000000e
0013 #define PVTMON_CONTROL0_SEL_TEMP_MONITOR        0x00000000
0014 #define PVTMON_CONTROL0_SEL_TEST_MODE           0x0000000e
0015 #define PVTMON_STATUS                   0x08
0016
0017 struct ns_thermal {
0018     struct thermal_zone_device *tz;
0019     void __iomem *pvtmon;
0020 };
0021
0022 static int ns_thermal_get_temp(void *data, int *temp)
0023 {
0024     struct ns_thermal *ns_thermal = data;
0025     int offset = thermal_zone_get_offset(ns_thermal->tz);
0026     int slope = thermal_zone_get_slope(ns_thermal->tz);
0027     u32 val;
0028
0029     val = readl(ns_thermal->pvtmon + PVTMON_CONTROL0);
0030     if ((val & PVTMON_CONTROL0_SEL_MASK) != PVTMON_CONTROL0_SEL_TEMP_MONITOR) {
0031         /* Clear current mode selection */
0032         val &= ~PVTMON_CONTROL0_SEL_MASK;
0033
0034         /* Set temp monitor mode (it's the default actually) */
0035         val |= PVTMON_CONTROL0_SEL_TEMP_MONITOR;
0036
0037         writel(val, ns_thermal->pvtmon + PVTMON_CONTROL0);
0038     }
0039
0040     val = readl(ns_thermal->pvtmon + PVTMON_STATUS);
0041     *temp = slope * val + offset;
0042
0043     return 0;
0044 }
0045
0046 static const struct thermal_zone_of_device_ops ns_thermal_ops = {
0047     .get_temp = ns_thermal_get_temp,
0048 };
0049
0050 static int ns_thermal_probe(struct platform_device *pdev)
0051 {
0052     struct device *dev = &pdev->dev;
0053     struct ns_thermal *ns_thermal;
0054
0055     ns_thermal = devm_kzalloc(dev, sizeof(*ns_thermal), GFP_KERNEL);
0056     if (!ns_thermal)
0057         return -ENOMEM;
0058
0059     ns_thermal->pvtmon = of_iomap(dev_of_node(dev), 0);
0060     if (WARN_ON(!ns_thermal->pvtmon))
0061         return -ENOENT;
0062
0063     ns_thermal->tz = devm_thermal_zone_of_sensor_register(dev, 0,
0064                                   ns_thermal,
0065                                   &ns_thermal_ops);
0066     if (IS_ERR(ns_thermal->tz)) {
0067         iounmap(ns_thermal->pvtmon);
0068         return PTR_ERR(ns_thermal->tz);
0069     }
0070
0071     platform_set_drvdata(pdev, ns_thermal);
0072
0073     return 0;
0074 }
0075
0076 static int ns_thermal_remove(struct platform_device *pdev)
0077 {
0078     struct ns_thermal *ns_thermal = platform_get_drvdata(pdev);
0079
0080     iounmap(ns_thermal->pvtmon);
0081
0082     return 0;
0083 }
0084
0085 static const struct of_device_id ns_thermal_of_match[] = {
0086     { .compatible = "brcm,ns-thermal", },
0087     {},
0088 };
0089 MODULE_DEVICE_TABLE(of, ns_thermal_of_match);
0090
0091 static struct platform_driver ns_thermal_driver = {
0092     .probe      = ns_thermal_probe,
0093     .remove     = ns_thermal_remove,
0094     .driver = {
0095         .name = "ns-thermal",
0096         .of_match_table = ns_thermal_of_match,
0097     },
0098 };
0099 module_platform_driver(ns_thermal_driver);
0100
0101 MODULE_AUTHOR("Rafał Miłecki <rafal@milecki.pl>");
0102 MODULE_DESCRIPTION("Northstar thermal driver");
0103 MODULE_LICENSE("GPL v2");