1 /* 2 * SPEAr thermal driver. 3 * 4 * Copyright (C) 2011-2012 ST Microelectronics 5 * Author: Vincenzo Frascino <vincenzo.frascino@st.com> 6 * 7 * This software is licensed under the terms of the GNU General Public 8 * License version 2, as published by the Free Software Foundation, and 9 * may be copied, distributed, and modified under those terms. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 */ 17 18 #include <linux/clk.h> 19 #include <linux/device.h> 20 #include <linux/err.h> 21 #include <linux/io.h> 22 #include <linux/kernel.h> 23 #include <linux/of.h> 24 #include <linux/module.h> 25 #include <linux/platform_device.h> 26 #include <linux/thermal.h> 27 28 #define MD_FACTOR 1000 29 30 /* SPEAr Thermal Sensor Dev Structure */ 31 struct spear_thermal_dev { 32 /* pointer to base address of the thermal sensor */ 33 void __iomem *thermal_base; 34 /* clk structure */ 35 struct clk *clk; 36 /* pointer to thermal flags */ 37 unsigned int flags; 38 }; 39 40 static inline int thermal_get_temp(struct thermal_zone_device *thermal, 41 int *temp) 42 { 43 struct spear_thermal_dev *stdev = thermal->devdata; 44 45 /* 46 * Data are ready to be read after 628 usec from POWERDOWN signal 47 * (PDN) = 1 48 */ 49 *temp = (readl_relaxed(stdev->thermal_base) & 0x7F) * MD_FACTOR; 50 return 0; 51 } 52 53 static struct thermal_zone_device_ops ops = { 54 .get_temp = thermal_get_temp, 55 }; 56 57 static int __maybe_unused spear_thermal_suspend(struct device *dev) 58 { 59 struct platform_device *pdev = to_platform_device(dev); 60 struct thermal_zone_device *spear_thermal = platform_get_drvdata(pdev); 61 struct spear_thermal_dev *stdev = spear_thermal->devdata; 62 unsigned int actual_mask = 0; 63 64 /* Disable SPEAr Thermal Sensor */ 65 actual_mask = readl_relaxed(stdev->thermal_base); 66 writel_relaxed(actual_mask & ~stdev->flags, stdev->thermal_base); 67 68 clk_disable(stdev->clk); 69 dev_info(dev, "Suspended.\n"); 70 71 return 0; 72 } 73 74 static int __maybe_unused spear_thermal_resume(struct device *dev) 75 { 76 struct platform_device *pdev = to_platform_device(dev); 77 struct thermal_zone_device *spear_thermal = platform_get_drvdata(pdev); 78 struct spear_thermal_dev *stdev = spear_thermal->devdata; 79 unsigned int actual_mask = 0; 80 int ret = 0; 81 82 ret = clk_enable(stdev->clk); 83 if (ret) { 84 dev_err(&pdev->dev, "Can't enable clock\n"); 85 return ret; 86 } 87 88 /* Enable SPEAr Thermal Sensor */ 89 actual_mask = readl_relaxed(stdev->thermal_base); 90 writel_relaxed(actual_mask | stdev->flags, stdev->thermal_base); 91 92 dev_info(dev, "Resumed.\n"); 93 94 return 0; 95 } 96 97 static SIMPLE_DEV_PM_OPS(spear_thermal_pm_ops, spear_thermal_suspend, 98 spear_thermal_resume); 99 100 static int spear_thermal_probe(struct platform_device *pdev) 101 { 102 struct thermal_zone_device *spear_thermal = NULL; 103 struct spear_thermal_dev *stdev; 104 struct device_node *np = pdev->dev.of_node; 105 struct resource *res; 106 int ret = 0, val; 107 108 if (!np || !of_property_read_u32(np, "st,thermal-flags", &val)) { 109 dev_err(&pdev->dev, "Failed: DT Pdata not passed\n"); 110 return -EINVAL; 111 } 112 113 stdev = devm_kzalloc(&pdev->dev, sizeof(*stdev), GFP_KERNEL); 114 if (!stdev) 115 return -ENOMEM; 116 117 /* Enable thermal sensor */ 118 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 119 stdev->thermal_base = devm_ioremap_resource(&pdev->dev, res); 120 if (IS_ERR(stdev->thermal_base)) 121 return PTR_ERR(stdev->thermal_base); 122 123 stdev->clk = devm_clk_get(&pdev->dev, NULL); 124 if (IS_ERR(stdev->clk)) { 125 dev_err(&pdev->dev, "Can't get clock\n"); 126 return PTR_ERR(stdev->clk); 127 } 128 129 ret = clk_enable(stdev->clk); 130 if (ret) { 131 dev_err(&pdev->dev, "Can't enable clock\n"); 132 return ret; 133 } 134 135 stdev->flags = val; 136 writel_relaxed(stdev->flags, stdev->thermal_base); 137 138 spear_thermal = thermal_zone_device_register("spear_thermal", 0, 0, 139 stdev, &ops, NULL, 0, 0); 140 if (IS_ERR(spear_thermal)) { 141 dev_err(&pdev->dev, "thermal zone device is NULL\n"); 142 ret = PTR_ERR(spear_thermal); 143 goto disable_clk; 144 } 145 146 platform_set_drvdata(pdev, spear_thermal); 147 148 dev_info(&spear_thermal->device, "Thermal Sensor Loaded at: 0x%p.\n", 149 stdev->thermal_base); 150 151 return 0; 152 153 disable_clk: 154 clk_disable(stdev->clk); 155 156 return ret; 157 } 158 159 static int spear_thermal_exit(struct platform_device *pdev) 160 { 161 unsigned int actual_mask = 0; 162 struct thermal_zone_device *spear_thermal = platform_get_drvdata(pdev); 163 struct spear_thermal_dev *stdev = spear_thermal->devdata; 164 165 thermal_zone_device_unregister(spear_thermal); 166 167 /* Disable SPEAr Thermal Sensor */ 168 actual_mask = readl_relaxed(stdev->thermal_base); 169 writel_relaxed(actual_mask & ~stdev->flags, stdev->thermal_base); 170 171 clk_disable(stdev->clk); 172 173 return 0; 174 } 175 176 static const struct of_device_id spear_thermal_id_table[] = { 177 { .compatible = "st,thermal-spear1340" }, 178 {} 179 }; 180 MODULE_DEVICE_TABLE(of, spear_thermal_id_table); 181 182 static struct platform_driver spear_thermal_driver = { 183 .probe = spear_thermal_probe, 184 .remove = spear_thermal_exit, 185 .driver = { 186 .name = "spear_thermal", 187 .pm = &spear_thermal_pm_ops, 188 .of_match_table = spear_thermal_id_table, 189 }, 190 }; 191 192 module_platform_driver(spear_thermal_driver); 193 194 MODULE_AUTHOR("Vincenzo Frascino <vincenzo.frascino@st.com>"); 195 MODULE_DESCRIPTION("SPEAr thermal driver"); 196 MODULE_LICENSE("GPL"); 197