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 unsigned long *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 #ifdef CONFIG_PM 58 static int spear_thermal_suspend(struct device *dev) 59 { 60 struct platform_device *pdev = to_platform_device(dev); 61 struct thermal_zone_device *spear_thermal = platform_get_drvdata(pdev); 62 struct spear_thermal_dev *stdev = spear_thermal->devdata; 63 unsigned int actual_mask = 0; 64 65 /* Disable SPEAr Thermal Sensor */ 66 actual_mask = readl_relaxed(stdev->thermal_base); 67 writel_relaxed(actual_mask & ~stdev->flags, stdev->thermal_base); 68 69 clk_disable(stdev->clk); 70 dev_info(dev, "Suspended.\n"); 71 72 return 0; 73 } 74 75 static int spear_thermal_resume(struct device *dev) 76 { 77 struct platform_device *pdev = to_platform_device(dev); 78 struct thermal_zone_device *spear_thermal = platform_get_drvdata(pdev); 79 struct spear_thermal_dev *stdev = spear_thermal->devdata; 80 unsigned int actual_mask = 0; 81 int ret = 0; 82 83 ret = clk_enable(stdev->clk); 84 if (ret) { 85 dev_err(&pdev->dev, "Can't enable clock\n"); 86 return ret; 87 } 88 89 /* Enable SPEAr Thermal Sensor */ 90 actual_mask = readl_relaxed(stdev->thermal_base); 91 writel_relaxed(actual_mask | stdev->flags, stdev->thermal_base); 92 93 dev_info(dev, "Resumed.\n"); 94 95 return 0; 96 } 97 #endif 98 99 static SIMPLE_DEV_PM_OPS(spear_thermal_pm_ops, spear_thermal_suspend, 100 spear_thermal_resume); 101 102 static int spear_thermal_probe(struct platform_device *pdev) 103 { 104 struct thermal_zone_device *spear_thermal = NULL; 105 struct spear_thermal_dev *stdev; 106 struct device_node *np = pdev->dev.of_node; 107 struct resource *stres = platform_get_resource(pdev, IORESOURCE_MEM, 0); 108 int ret = 0, val; 109 110 if (!np || !of_property_read_u32(np, "st,thermal-flags", &val)) { 111 dev_err(&pdev->dev, "Failed: DT Pdata not passed\n"); 112 return -EINVAL; 113 } 114 115 if (!stres) { 116 dev_err(&pdev->dev, "memory resource missing\n"); 117 return -ENODEV; 118 } 119 120 stdev = devm_kzalloc(&pdev->dev, sizeof(*stdev), GFP_KERNEL); 121 if (!stdev) { 122 dev_err(&pdev->dev, "kzalloc fail\n"); 123 return -ENOMEM; 124 } 125 126 /* Enable thermal sensor */ 127 stdev->thermal_base = devm_ioremap(&pdev->dev, stres->start, 128 resource_size(stres)); 129 if (!stdev->thermal_base) { 130 dev_err(&pdev->dev, "ioremap failed\n"); 131 return -ENOMEM; 132 } 133 134 stdev->clk = clk_get(&pdev->dev, NULL); 135 if (IS_ERR(stdev->clk)) { 136 dev_err(&pdev->dev, "Can't get clock\n"); 137 return PTR_ERR(stdev->clk); 138 } 139 140 ret = clk_enable(stdev->clk); 141 if (ret) { 142 dev_err(&pdev->dev, "Can't enable clock\n"); 143 goto put_clk; 144 } 145 146 stdev->flags = val; 147 writel_relaxed(stdev->flags, stdev->thermal_base); 148 149 spear_thermal = thermal_zone_device_register("spear_thermal", 0, 0, 150 stdev, &ops, NULL, 0, 0); 151 if (IS_ERR(spear_thermal)) { 152 dev_err(&pdev->dev, "thermal zone device is NULL\n"); 153 ret = PTR_ERR(spear_thermal); 154 goto disable_clk; 155 } 156 157 platform_set_drvdata(pdev, spear_thermal); 158 159 dev_info(&spear_thermal->device, "Thermal Sensor Loaded at: 0x%p.\n", 160 stdev->thermal_base); 161 162 return 0; 163 164 disable_clk: 165 clk_disable(stdev->clk); 166 put_clk: 167 clk_put(stdev->clk); 168 169 return ret; 170 } 171 172 static int spear_thermal_exit(struct platform_device *pdev) 173 { 174 unsigned int actual_mask = 0; 175 struct thermal_zone_device *spear_thermal = platform_get_drvdata(pdev); 176 struct spear_thermal_dev *stdev = spear_thermal->devdata; 177 178 thermal_zone_device_unregister(spear_thermal); 179 platform_set_drvdata(pdev, NULL); 180 181 /* Disable SPEAr Thermal Sensor */ 182 actual_mask = readl_relaxed(stdev->thermal_base); 183 writel_relaxed(actual_mask & ~stdev->flags, stdev->thermal_base); 184 185 clk_disable(stdev->clk); 186 clk_put(stdev->clk); 187 188 return 0; 189 } 190 191 static const struct of_device_id spear_thermal_id_table[] = { 192 { .compatible = "st,thermal-spear1340" }, 193 {} 194 }; 195 MODULE_DEVICE_TABLE(of, spear_thermal_id_table); 196 197 static struct platform_driver spear_thermal_driver = { 198 .probe = spear_thermal_probe, 199 .remove = spear_thermal_exit, 200 .driver = { 201 .name = "spear_thermal", 202 .owner = THIS_MODULE, 203 .pm = &spear_thermal_pm_ops, 204 .of_match_table = of_match_ptr(spear_thermal_id_table), 205 }, 206 }; 207 208 module_platform_driver(spear_thermal_driver); 209 210 MODULE_AUTHOR("Vincenzo Frascino <vincenzo.frascino@st.com>"); 211 MODULE_DESCRIPTION("SPEAr thermal driver"); 212 MODULE_LICENSE("GPL"); 213