spear_thermal.c (4905B)
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 */ 22struct 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 31static inline int thermal_get_temp(struct thermal_zone_device *thermal, 32 int *temp) 33{ 34 struct spear_thermal_dev *stdev = thermal->devdata; 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 44static struct thermal_zone_device_ops ops = { 45 .get_temp = thermal_get_temp, 46}; 47 48static 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 = spear_thermal->devdata; 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 64static 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 = spear_thermal->devdata; 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 86static SIMPLE_DEV_PM_OPS(spear_thermal_pm_ops, spear_thermal_suspend, 87 spear_thermal_resume); 88 89static 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 struct resource *res; 95 int ret = 0, val; 96 97 if (!np || !of_property_read_u32(np, "st,thermal-flags", &val)) { 98 dev_err(&pdev->dev, "Failed: DT Pdata not passed\n"); 99 return -EINVAL; 100 } 101 102 stdev = devm_kzalloc(&pdev->dev, sizeof(*stdev), GFP_KERNEL); 103 if (!stdev) 104 return -ENOMEM; 105 106 /* Enable thermal sensor */ 107 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 108 stdev->thermal_base = devm_ioremap_resource(&pdev->dev, res); 109 if (IS_ERR(stdev->thermal_base)) 110 return PTR_ERR(stdev->thermal_base); 111 112 stdev->clk = devm_clk_get(&pdev->dev, NULL); 113 if (IS_ERR(stdev->clk)) { 114 dev_err(&pdev->dev, "Can't get clock\n"); 115 return PTR_ERR(stdev->clk); 116 } 117 118 ret = clk_enable(stdev->clk); 119 if (ret) { 120 dev_err(&pdev->dev, "Can't enable clock\n"); 121 return ret; 122 } 123 124 stdev->flags = val; 125 writel_relaxed(stdev->flags, stdev->thermal_base); 126 127 spear_thermal = thermal_zone_device_register("spear_thermal", 0, 0, 128 stdev, &ops, NULL, 0, 0); 129 if (IS_ERR(spear_thermal)) { 130 dev_err(&pdev->dev, "thermal zone device is NULL\n"); 131 ret = PTR_ERR(spear_thermal); 132 goto disable_clk; 133 } 134 ret = thermal_zone_device_enable(spear_thermal); 135 if (ret) { 136 dev_err(&pdev->dev, "Cannot enable thermal zone\n"); 137 goto unregister_tzd; 138 } 139 140 platform_set_drvdata(pdev, spear_thermal); 141 142 dev_info(&spear_thermal->device, "Thermal Sensor Loaded at: 0x%p.\n", 143 stdev->thermal_base); 144 145 return 0; 146 147unregister_tzd: 148 thermal_zone_device_unregister(spear_thermal); 149disable_clk: 150 clk_disable(stdev->clk); 151 152 return ret; 153} 154 155static int spear_thermal_exit(struct platform_device *pdev) 156{ 157 unsigned int actual_mask = 0; 158 struct thermal_zone_device *spear_thermal = platform_get_drvdata(pdev); 159 struct spear_thermal_dev *stdev = spear_thermal->devdata; 160 161 thermal_zone_device_unregister(spear_thermal); 162 163 /* Disable SPEAr Thermal Sensor */ 164 actual_mask = readl_relaxed(stdev->thermal_base); 165 writel_relaxed(actual_mask & ~stdev->flags, stdev->thermal_base); 166 167 clk_disable(stdev->clk); 168 169 return 0; 170} 171 172static const struct of_device_id spear_thermal_id_table[] = { 173 { .compatible = "st,thermal-spear1340" }, 174 {} 175}; 176MODULE_DEVICE_TABLE(of, spear_thermal_id_table); 177 178static struct platform_driver spear_thermal_driver = { 179 .probe = spear_thermal_probe, 180 .remove = spear_thermal_exit, 181 .driver = { 182 .name = "spear_thermal", 183 .pm = &spear_thermal_pm_ops, 184 .of_match_table = spear_thermal_id_table, 185 }, 186}; 187 188module_platform_driver(spear_thermal_driver); 189 190MODULE_AUTHOR("Vincenzo Frascino <vincenzo.frascino@st.com>"); 191MODULE_DESCRIPTION("SPEAr thermal driver"); 192MODULE_LICENSE("GPL");