| 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->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 | |
| 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 = 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 | |
| 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 = 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 | |
| 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 | 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 | |
| 147 | unregister_tzd: |
| 148 | thermal_zone_device_unregister(spear_thermal); |
| 149 | disable_clk: |
| 150 | clk_disable(stdev->clk); |
| 151 | |
| 152 | return ret; |
| 153 | } |
| 154 | |
| 155 | static 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 | |
| 172 | static const struct of_device_id spear_thermal_id_table[] = { |
| 173 | { .compatible = "st,thermal-spear1340" }, |
| 174 | {} |
| 175 | }; |
| 176 | MODULE_DEVICE_TABLE(of, spear_thermal_id_table); |
| 177 | |
| 178 | static 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 | |
| 188 | module_platform_driver(spear_thermal_driver); |
| 189 | |
| 190 | MODULE_AUTHOR("Vincenzo Frascino <vincenzo.frascino@st.com>"); |
| 191 | MODULE_DESCRIPTION("SPEAr thermal driver"); |
| 192 | MODULE_LICENSE("GPL"); |