1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * SPEAr thermal driver. 4 * 5 * Copyright (C) 2011-2012 ST Microelectronics 6 * Author: Vincenzo Frascino <vincenzo.frascino@st.com> 7 */ 8 9 #include <linux/clk.h> 10 #include <linux/device.h> 11 #include <linux/err.h> 12 #include <linux/io.h> 13 #include <linux/kernel.h> 14 #include <linux/of.h> 15 #include <linux/module.h> 16 #include <linux/platform_device.h> 17 #include <linux/thermal.h> 18 19 #define MD_FACTOR 1000 20 21 /* SPEAr Thermal Sensor Dev Structure */ 22 struct spear_thermal_dev { 23 /* pointer to base address of the thermal sensor */ 24 void __iomem *thermal_base; 25 /* clk structure */ 26 struct clk *clk; 27 /* pointer to thermal flags */ 28 unsigned int flags; 29 }; 30 31 static inline int thermal_get_temp(struct thermal_zone_device *thermal, 32 int *temp) 33 { 34 struct spear_thermal_dev *stdev = thermal_zone_device_priv(thermal); 35 36 /* 37 * Data are ready to be read after 628 usec from POWERDOWN signal 38 * (PDN) = 1 39 */ 40 *temp = (readl_relaxed(stdev->thermal_base) & 0x7F) * MD_FACTOR; 41 return 0; 42 } 43 44 static struct thermal_zone_device_ops ops = { 45 .get_temp = thermal_get_temp, 46 }; 47 48 static int __maybe_unused spear_thermal_suspend(struct device *dev) 49 { 50 struct thermal_zone_device *spear_thermal = dev_get_drvdata(dev); 51 struct spear_thermal_dev *stdev = thermal_zone_device_priv(spear_thermal); 52 unsigned int actual_mask = 0; 53 54 /* Disable SPEAr Thermal Sensor */ 55 actual_mask = readl_relaxed(stdev->thermal_base); 56 writel_relaxed(actual_mask & ~stdev->flags, stdev->thermal_base); 57 58 clk_disable(stdev->clk); 59 dev_info(dev, "Suspended.\n"); 60 61 return 0; 62 } 63 64 static int __maybe_unused spear_thermal_resume(struct device *dev) 65 { 66 struct thermal_zone_device *spear_thermal = dev_get_drvdata(dev); 67 struct spear_thermal_dev *stdev = thermal_zone_device_priv(spear_thermal); 68 unsigned int actual_mask = 0; 69 int ret = 0; 70 71 ret = clk_enable(stdev->clk); 72 if (ret) { 73 dev_err(dev, "Can't enable clock\n"); 74 return ret; 75 } 76 77 /* Enable SPEAr Thermal Sensor */ 78 actual_mask = readl_relaxed(stdev->thermal_base); 79 writel_relaxed(actual_mask | stdev->flags, stdev->thermal_base); 80 81 dev_info(dev, "Resumed.\n"); 82 83 return 0; 84 } 85 86 static SIMPLE_DEV_PM_OPS(spear_thermal_pm_ops, spear_thermal_suspend, 87 spear_thermal_resume); 88 89 static int spear_thermal_probe(struct platform_device *pdev) 90 { 91 struct thermal_zone_device *spear_thermal = NULL; 92 struct spear_thermal_dev *stdev; 93 struct device_node *np = pdev->dev.of_node; 94 int ret = 0, val; 95 96 if (!np || !of_property_read_u32(np, "st,thermal-flags", &val)) { 97 dev_err(&pdev->dev, "Failed: DT Pdata not passed\n"); 98 return -EINVAL; 99 } 100 101 stdev = devm_kzalloc(&pdev->dev, sizeof(*stdev), GFP_KERNEL); 102 if (!stdev) 103 return -ENOMEM; 104 105 /* Enable thermal sensor */ 106 stdev->thermal_base = devm_platform_get_and_ioremap_resource(pdev, 0, NULL); 107 if (IS_ERR(stdev->thermal_base)) 108 return PTR_ERR(stdev->thermal_base); 109 110 stdev->clk = devm_clk_get(&pdev->dev, NULL); 111 if (IS_ERR(stdev->clk)) { 112 dev_err(&pdev->dev, "Can't get clock\n"); 113 return PTR_ERR(stdev->clk); 114 } 115 116 ret = clk_enable(stdev->clk); 117 if (ret) { 118 dev_err(&pdev->dev, "Can't enable clock\n"); 119 return ret; 120 } 121 122 stdev->flags = val; 123 writel_relaxed(stdev->flags, stdev->thermal_base); 124 125 spear_thermal = thermal_tripless_zone_device_register("spear_thermal", 126 stdev, &ops, NULL); 127 if (IS_ERR(spear_thermal)) { 128 dev_err(&pdev->dev, "thermal zone device is NULL\n"); 129 ret = PTR_ERR(spear_thermal); 130 goto disable_clk; 131 } 132 ret = thermal_zone_device_enable(spear_thermal); 133 if (ret) { 134 dev_err(&pdev->dev, "Cannot enable thermal zone\n"); 135 goto unregister_tzd; 136 } 137 138 platform_set_drvdata(pdev, spear_thermal); 139 140 dev_info(&pdev->dev, "Thermal Sensor Loaded at: 0x%p.\n", 141 stdev->thermal_base); 142 143 return 0; 144 145 unregister_tzd: 146 thermal_zone_device_unregister(spear_thermal); 147 disable_clk: 148 clk_disable(stdev->clk); 149 150 return ret; 151 } 152 153 static void spear_thermal_exit(struct platform_device *pdev) 154 { 155 unsigned int actual_mask = 0; 156 struct thermal_zone_device *spear_thermal = platform_get_drvdata(pdev); 157 struct spear_thermal_dev *stdev = thermal_zone_device_priv(spear_thermal); 158 159 thermal_zone_device_unregister(spear_thermal); 160 161 /* Disable SPEAr Thermal Sensor */ 162 actual_mask = readl_relaxed(stdev->thermal_base); 163 writel_relaxed(actual_mask & ~stdev->flags, stdev->thermal_base); 164 165 clk_disable(stdev->clk); 166 } 167 168 static const struct of_device_id spear_thermal_id_table[] = { 169 { .compatible = "st,thermal-spear1340" }, 170 {} 171 }; 172 MODULE_DEVICE_TABLE(of, spear_thermal_id_table); 173 174 static struct platform_driver spear_thermal_driver = { 175 .probe = spear_thermal_probe, 176 .remove_new = spear_thermal_exit, 177 .driver = { 178 .name = "spear_thermal", 179 .pm = &spear_thermal_pm_ops, 180 .of_match_table = spear_thermal_id_table, 181 }, 182 }; 183 184 module_platform_driver(spear_thermal_driver); 185 186 MODULE_AUTHOR("Vincenzo Frascino <vincenzo.frascino@st.com>"); 187 MODULE_DESCRIPTION("SPEAr thermal driver"); 188 MODULE_LICENSE("GPL"); 189