drivers/thermal/spear_thermal.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * SPEAr thermal driver.
0004  *
0005  * Copyright (C) 2011-2012 ST Microelectronics
0006  * Author: Vincenzo Frascino <vincenzo.frascino@st.com>
0007  */
0008
0009 #include <linux/clk.h>
0010 #include <linux/device.h>
0011 #include <linux/err.h>
0012 #include <linux/io.h>
0013 #include <linux/kernel.h>
0014 #include <linux/of.h>
0015 #include <linux/module.h>
0016 #include <linux/platform_device.h>
0017 #include <linux/thermal.h>
0018
0019 #define MD_FACTOR   1000
0020
0021 /* SPEAr Thermal Sensor Dev Structure */
0022 struct spear_thermal_dev {
0023     /* pointer to base address of the thermal sensor */
0024     void __iomem *thermal_base;
0025     /* clk structure */
0026     struct clk *clk;
0027     /* pointer to thermal flags */
0028     unsigned int flags;
0029 };
0030
0031 static inline int thermal_get_temp(struct thermal_zone_device *thermal,
0032                 int *temp)
0033 {
0034     struct spear_thermal_dev *stdev = thermal->devdata;
0035
0036     /*
0037      * Data are ready to be read after 628 usec from POWERDOWN signal
0038      * (PDN) = 1
0039      */
0040     *temp = (readl_relaxed(stdev->thermal_base) & 0x7F) * MD_FACTOR;
0041     return 0;
0042 }
0043
0044 static struct thermal_zone_device_ops ops = {
0045     .get_temp = thermal_get_temp,
0046 };
0047
0048 static int __maybe_unused spear_thermal_suspend(struct device *dev)
0049 {
0050     struct thermal_zone_device *spear_thermal = dev_get_drvdata(dev);
0051     struct spear_thermal_dev *stdev = spear_thermal->devdata;
0052     unsigned int actual_mask = 0;
0053
0054     /* Disable SPEAr Thermal Sensor */
0055     actual_mask = readl_relaxed(stdev->thermal_base);
0056     writel_relaxed(actual_mask & ~stdev->flags, stdev->thermal_base);
0057
0058     clk_disable(stdev->clk);
0059     dev_info(dev, "Suspended.\n");
0060
0061     return 0;
0062 }
0063
0064 static int __maybe_unused spear_thermal_resume(struct device *dev)
0065 {
0066     struct thermal_zone_device *spear_thermal = dev_get_drvdata(dev);
0067     struct spear_thermal_dev *stdev = spear_thermal->devdata;
0068     unsigned int actual_mask = 0;
0069     int ret = 0;
0070
0071     ret = clk_enable(stdev->clk);
0072     if (ret) {
0073         dev_err(dev, "Can't enable clock\n");
0074         return ret;
0075     }
0076
0077     /* Enable SPEAr Thermal Sensor */
0078     actual_mask = readl_relaxed(stdev->thermal_base);
0079     writel_relaxed(actual_mask | stdev->flags, stdev->thermal_base);
0080
0081     dev_info(dev, "Resumed.\n");
0082
0083     return 0;
0084 }
0085
0086 static SIMPLE_DEV_PM_OPS(spear_thermal_pm_ops, spear_thermal_suspend,
0087         spear_thermal_resume);
0088
0089 static int spear_thermal_probe(struct platform_device *pdev)
0090 {
0091     struct thermal_zone_device *spear_thermal = NULL;
0092     struct spear_thermal_dev *stdev;
0093     struct device_node *np = pdev->dev.of_node;
0094     struct resource *res;
0095     int ret = 0, val;
0096
0097     if (!np || !of_property_read_u32(np, "st,thermal-flags", &val)) {
0098         dev_err(&pdev->dev, "Failed: DT Pdata not passed\n");
0099         return -EINVAL;
0100     }
0101
0102     stdev = devm_kzalloc(&pdev->dev, sizeof(*stdev), GFP_KERNEL);
0103     if (!stdev)
0104         return -ENOMEM;
0105
0106     /* Enable thermal sensor */
0107     res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
0108     stdev->thermal_base = devm_ioremap_resource(&pdev->dev, res);
0109     if (IS_ERR(stdev->thermal_base))
0110         return PTR_ERR(stdev->thermal_base);
0111
0112     stdev->clk = devm_clk_get(&pdev->dev, NULL);
0113     if (IS_ERR(stdev->clk)) {
0114         dev_err(&pdev->dev, "Can't get clock\n");
0115         return PTR_ERR(stdev->clk);
0116     }
0117
0118     ret = clk_enable(stdev->clk);
0119     if (ret) {
0120         dev_err(&pdev->dev, "Can't enable clock\n");
0121         return ret;
0122     }
0123
0124     stdev->flags = val;
0125     writel_relaxed(stdev->flags, stdev->thermal_base);
0126
0127     spear_thermal = thermal_zone_device_register("spear_thermal", 0, 0,
0128                 stdev, &ops, NULL, 0, 0);
0129     if (IS_ERR(spear_thermal)) {
0130         dev_err(&pdev->dev, "thermal zone device is NULL\n");
0131         ret = PTR_ERR(spear_thermal);
0132         goto disable_clk;
0133     }
0134     ret = thermal_zone_device_enable(spear_thermal);
0135     if (ret) {
0136         dev_err(&pdev->dev, "Cannot enable thermal zone\n");
0137         goto unregister_tzd;
0138     }
0139
0140     platform_set_drvdata(pdev, spear_thermal);
0141
0142     dev_info(&spear_thermal->device, "Thermal Sensor Loaded at: 0x%p.\n",
0143             stdev->thermal_base);
0144
0145     return 0;
0146
0147 unregister_tzd:
0148     thermal_zone_device_unregister(spear_thermal);
0149 disable_clk:
0150     clk_disable(stdev->clk);
0151
0152     return ret;
0153 }
0154
0155 static int spear_thermal_exit(struct platform_device *pdev)
0156 {
0157     unsigned int actual_mask = 0;
0158     struct thermal_zone_device *spear_thermal = platform_get_drvdata(pdev);
0159     struct spear_thermal_dev *stdev = spear_thermal->devdata;
0160
0161     thermal_zone_device_unregister(spear_thermal);
0162
0163     /* Disable SPEAr Thermal Sensor */
0164     actual_mask = readl_relaxed(stdev->thermal_base);
0165     writel_relaxed(actual_mask & ~stdev->flags, stdev->thermal_base);
0166
0167     clk_disable(stdev->clk);
0168
0169     return 0;
0170 }
0171
0172 static const struct of_device_id spear_thermal_id_table[] = {
0173     { .compatible = "st,thermal-spear1340" },
0174     {}
0175 };
0176 MODULE_DEVICE_TABLE(of, spear_thermal_id_table);
0177
0178 static struct platform_driver spear_thermal_driver = {
0179     .probe = spear_thermal_probe,
0180     .remove = spear_thermal_exit,
0181     .driver = {
0182         .name = "spear_thermal",
0183         .pm = &spear_thermal_pm_ops,
0184         .of_match_table = spear_thermal_id_table,
0185     },
0186 };
0187
0188 module_platform_driver(spear_thermal_driver);
0189
0190 MODULE_AUTHOR("Vincenzo Frascino <vincenzo.frascino@st.com>");
0191 MODULE_DESCRIPTION("SPEAr thermal driver");
0192 MODULE_LICENSE("GPL");