1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Synaptics AS370 SoC Hardware Monitoring Driver 4 * 5 * Copyright (C) 2018 Synaptics Incorporated 6 * Author: Jisheng Zhang <jszhang@kernel.org> 7 */ 8 9 #include <linux/bitops.h> 10 #include <linux/hwmon.h> 11 #include <linux/init.h> 12 #include <linux/io.h> 13 #include <linux/module.h> 14 #include <linux/of_device.h> 15 16 #define CTRL 0x0 17 #define PD BIT(0) 18 #define EN BIT(1) 19 #define T_SEL BIT(2) 20 #define V_SEL BIT(3) 21 #define NMOS_SEL BIT(8) 22 #define PMOS_SEL BIT(9) 23 #define STS 0x4 24 #define BN_MASK GENMASK(11, 0) 25 #define EOC BIT(12) 26 27 struct as370_hwmon { 28 void __iomem *base; 29 }; 30 31 static void init_pvt(struct as370_hwmon *hwmon) 32 { 33 u32 val; 34 void __iomem *addr = hwmon->base + CTRL; 35 36 val = PD; 37 writel_relaxed(val, addr); 38 val |= T_SEL; 39 writel_relaxed(val, addr); 40 val |= EN; 41 writel_relaxed(val, addr); 42 val &= ~PD; 43 writel_relaxed(val, addr); 44 } 45 46 static int as370_hwmon_read(struct device *dev, enum hwmon_sensor_types type, 47 u32 attr, int channel, long *temp) 48 { 49 int val; 50 struct as370_hwmon *hwmon = dev_get_drvdata(dev); 51 52 switch (attr) { 53 case hwmon_temp_input: 54 val = readl_relaxed(hwmon->base + STS) & BN_MASK; 55 *temp = DIV_ROUND_CLOSEST(val * 251802, 4096) - 85525; 56 break; 57 default: 58 return -EOPNOTSUPP; 59 } 60 61 return 0; 62 } 63 64 static umode_t 65 as370_hwmon_is_visible(const void *data, enum hwmon_sensor_types type, 66 u32 attr, int channel) 67 { 68 if (type != hwmon_temp) 69 return 0; 70 71 switch (attr) { 72 case hwmon_temp_input: 73 return 0444; 74 default: 75 return 0; 76 } 77 } 78 79 static const struct hwmon_channel_info *as370_hwmon_info[] = { 80 HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT), 81 NULL 82 }; 83 84 static const struct hwmon_ops as370_hwmon_ops = { 85 .is_visible = as370_hwmon_is_visible, 86 .read = as370_hwmon_read, 87 }; 88 89 static const struct hwmon_chip_info as370_chip_info = { 90 .ops = &as370_hwmon_ops, 91 .info = as370_hwmon_info, 92 }; 93 94 static int as370_hwmon_probe(struct platform_device *pdev) 95 { 96 struct device *hwmon_dev; 97 struct as370_hwmon *hwmon; 98 struct device *dev = &pdev->dev; 99 100 hwmon = devm_kzalloc(dev, sizeof(*hwmon), GFP_KERNEL); 101 if (!hwmon) 102 return -ENOMEM; 103 104 hwmon->base = devm_platform_ioremap_resource(pdev, 0); 105 if (IS_ERR(hwmon->base)) 106 return PTR_ERR(hwmon->base); 107 108 init_pvt(hwmon); 109 110 hwmon_dev = devm_hwmon_device_register_with_info(dev, 111 "as370", 112 hwmon, 113 &as370_chip_info, 114 NULL); 115 return PTR_ERR_OR_ZERO(hwmon_dev); 116 } 117 118 static const struct of_device_id as370_hwmon_match[] = { 119 { .compatible = "syna,as370-hwmon" }, 120 {}, 121 }; 122 MODULE_DEVICE_TABLE(of, as370_hwmon_match); 123 124 static struct platform_driver as370_hwmon_driver = { 125 .probe = as370_hwmon_probe, 126 .driver = { 127 .name = "as370-hwmon", 128 .of_match_table = as370_hwmon_match, 129 }, 130 }; 131 module_platform_driver(as370_hwmon_driver); 132 133 MODULE_AUTHOR("Jisheng Zhang<jszhang@kernel.org>"); 134 MODULE_DESCRIPTION("Synaptics AS370 SoC hardware monitor"); 135 MODULE_LICENSE("GPL v2"); 136