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/mod_devicetable.h> 15 #include <linux/platform_device.h> 16 17 #define CTRL 0x0 18 #define PD BIT(0) 19 #define EN BIT(1) 20 #define T_SEL BIT(2) 21 #define V_SEL BIT(3) 22 #define NMOS_SEL BIT(8) 23 #define PMOS_SEL BIT(9) 24 #define STS 0x4 25 #define BN_MASK GENMASK(11, 0) 26 #define EOC BIT(12) 27 28 struct as370_hwmon { 29 void __iomem *base; 30 }; 31 32 static void init_pvt(struct as370_hwmon *hwmon) 33 { 34 u32 val; 35 void __iomem *addr = hwmon->base + CTRL; 36 37 val = PD; 38 writel_relaxed(val, addr); 39 val |= T_SEL; 40 writel_relaxed(val, addr); 41 val |= EN; 42 writel_relaxed(val, addr); 43 val &= ~PD; 44 writel_relaxed(val, addr); 45 } 46 47 static int as370_hwmon_read(struct device *dev, enum hwmon_sensor_types type, 48 u32 attr, int channel, long *temp) 49 { 50 int val; 51 struct as370_hwmon *hwmon = dev_get_drvdata(dev); 52 53 switch (attr) { 54 case hwmon_temp_input: 55 val = readl_relaxed(hwmon->base + STS) & BN_MASK; 56 *temp = DIV_ROUND_CLOSEST(val * 251802, 4096) - 85525; 57 break; 58 default: 59 return -EOPNOTSUPP; 60 } 61 62 return 0; 63 } 64 65 static umode_t 66 as370_hwmon_is_visible(const void *data, enum hwmon_sensor_types type, 67 u32 attr, int channel) 68 { 69 if (type != hwmon_temp) 70 return 0; 71 72 switch (attr) { 73 case hwmon_temp_input: 74 return 0444; 75 default: 76 return 0; 77 } 78 } 79 80 static const struct hwmon_channel_info * const as370_hwmon_info[] = { 81 HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT), 82 NULL 83 }; 84 85 static const struct hwmon_ops as370_hwmon_ops = { 86 .is_visible = as370_hwmon_is_visible, 87 .read = as370_hwmon_read, 88 }; 89 90 static const struct hwmon_chip_info as370_chip_info = { 91 .ops = &as370_hwmon_ops, 92 .info = as370_hwmon_info, 93 }; 94 95 static int as370_hwmon_probe(struct platform_device *pdev) 96 { 97 struct device *hwmon_dev; 98 struct as370_hwmon *hwmon; 99 struct device *dev = &pdev->dev; 100 101 hwmon = devm_kzalloc(dev, sizeof(*hwmon), GFP_KERNEL); 102 if (!hwmon) 103 return -ENOMEM; 104 105 hwmon->base = devm_platform_ioremap_resource(pdev, 0); 106 if (IS_ERR(hwmon->base)) 107 return PTR_ERR(hwmon->base); 108 109 init_pvt(hwmon); 110 111 hwmon_dev = devm_hwmon_device_register_with_info(dev, 112 "as370", 113 hwmon, 114 &as370_chip_info, 115 NULL); 116 return PTR_ERR_OR_ZERO(hwmon_dev); 117 } 118 119 static const struct of_device_id as370_hwmon_match[] = { 120 { .compatible = "syna,as370-hwmon" }, 121 {}, 122 }; 123 MODULE_DEVICE_TABLE(of, as370_hwmon_match); 124 125 static struct platform_driver as370_hwmon_driver = { 126 .probe = as370_hwmon_probe, 127 .driver = { 128 .name = "as370-hwmon", 129 .of_match_table = as370_hwmon_match, 130 }, 131 }; 132 module_platform_driver(as370_hwmon_driver); 133 134 MODULE_AUTHOR("Jisheng Zhang<jszhang@kernel.org>"); 135 MODULE_DESCRIPTION("Synaptics AS370 SoC hardware monitor"); 136 MODULE_LICENSE("GPL v2"); 137