1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* Sparx5 SoC temperature sensor driver 3 * 4 * Copyright (C) 2020 Lars Povlsen <lars.povlsen@microchip.com> 5 */ 6 7 #include <linux/bitfield.h> 8 #include <linux/clk.h> 9 #include <linux/hwmon.h> 10 #include <linux/init.h> 11 #include <linux/io.h> 12 #include <linux/mod_devicetable.h> 13 #include <linux/module.h> 14 #include <linux/platform_device.h> 15 16 #define TEMP_CTRL 0 17 #define TEMP_CFG 4 18 #define TEMP_CFG_CYCLES GENMASK(24, 15) 19 #define TEMP_CFG_ENA BIT(0) 20 #define TEMP_STAT 8 21 #define TEMP_STAT_VALID BIT(12) 22 #define TEMP_STAT_TEMP GENMASK(11, 0) 23 24 struct s5_hwmon { 25 void __iomem *base; 26 struct clk *clk; 27 }; 28 29 static void s5_temp_enable(struct s5_hwmon *hwmon) 30 { 31 u32 val = readl(hwmon->base + TEMP_CFG); 32 u32 clk = clk_get_rate(hwmon->clk) / USEC_PER_SEC; 33 34 val &= ~TEMP_CFG_CYCLES; 35 val |= FIELD_PREP(TEMP_CFG_CYCLES, clk); 36 val |= TEMP_CFG_ENA; 37 38 writel(val, hwmon->base + TEMP_CFG); 39 } 40 41 static int s5_read(struct device *dev, enum hwmon_sensor_types type, 42 u32 attr, int channel, long *temp) 43 { 44 struct s5_hwmon *hwmon = dev_get_drvdata(dev); 45 int rc = 0, value; 46 u32 stat; 47 48 switch (attr) { 49 case hwmon_temp_input: 50 stat = readl_relaxed(hwmon->base + TEMP_STAT); 51 if (!(stat & TEMP_STAT_VALID)) 52 return -EAGAIN; 53 value = stat & TEMP_STAT_TEMP; 54 /* 55 * From register documentation: 56 * Temp(C) = TEMP_SENSOR_STAT.TEMP / 4096 * 352.2 - 109.4 57 */ 58 value = DIV_ROUND_CLOSEST(value * 3522, 4096) - 1094; 59 /* 60 * Scale down by 10 from above and multiply by 1000 to 61 * have millidegrees as specified by the hwmon sysfs 62 * interface. 63 */ 64 value *= 100; 65 *temp = value; 66 break; 67 default: 68 rc = -EOPNOTSUPP; 69 break; 70 } 71 72 return rc; 73 } 74 75 static umode_t s5_is_visible(const void *_data, enum hwmon_sensor_types type, 76 u32 attr, int channel) 77 { 78 if (type != hwmon_temp) 79 return 0; 80 81 switch (attr) { 82 case hwmon_temp_input: 83 return 0444; 84 default: 85 return 0; 86 } 87 } 88 89 static const struct hwmon_channel_info * const s5_info[] = { 90 HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ), 91 HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT), 92 NULL 93 }; 94 95 static const struct hwmon_ops s5_hwmon_ops = { 96 .is_visible = s5_is_visible, 97 .read = s5_read, 98 }; 99 100 static const struct hwmon_chip_info s5_chip_info = { 101 .ops = &s5_hwmon_ops, 102 .info = s5_info, 103 }; 104 105 static int s5_temp_probe(struct platform_device *pdev) 106 { 107 struct device *hwmon_dev; 108 struct s5_hwmon *hwmon; 109 110 hwmon = devm_kzalloc(&pdev->dev, sizeof(*hwmon), GFP_KERNEL); 111 if (!hwmon) 112 return -ENOMEM; 113 114 hwmon->base = devm_platform_ioremap_resource(pdev, 0); 115 if (IS_ERR(hwmon->base)) 116 return PTR_ERR(hwmon->base); 117 118 hwmon->clk = devm_clk_get_enabled(&pdev->dev, NULL); 119 if (IS_ERR(hwmon->clk)) 120 return PTR_ERR(hwmon->clk); 121 122 s5_temp_enable(hwmon); 123 124 hwmon_dev = devm_hwmon_device_register_with_info(&pdev->dev, 125 "s5_temp", 126 hwmon, 127 &s5_chip_info, 128 NULL); 129 130 return PTR_ERR_OR_ZERO(hwmon_dev); 131 } 132 133 static const struct of_device_id s5_temp_match[] = { 134 { .compatible = "microchip,sparx5-temp" }, 135 {}, 136 }; 137 MODULE_DEVICE_TABLE(of, s5_temp_match); 138 139 static struct platform_driver s5_temp_driver = { 140 .probe = s5_temp_probe, 141 .driver = { 142 .name = "sparx5-temp", 143 .of_match_table = s5_temp_match, 144 }, 145 }; 146 147 module_platform_driver(s5_temp_driver); 148 149 MODULE_AUTHOR("Lars Povlsen <lars.povlsen@microchip.com>"); 150 MODULE_DESCRIPTION("Sparx5 SoC temperature sensor driver"); 151 MODULE_LICENSE("GPL"); 152