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1// SPDX-License-Identifier: GPL-2.0-only2/* Copyright (C) 2022 Hewlett-Packard Enterprise Development Company, L.P. */3 4#include <linux/bits.h>5#include <linux/err.h>6#include <linux/hwmon.h>7#include <linux/io.h>8#include <linux/module.h>9#include <linux/mod_devicetable.h>10#include <linux/platform_device.h>11 12#define OFS_FAN_INST 0 /* Is 0 because plreg base will be set at INST */13#define OFS_FAN_FAIL 2 /* Is 2 bytes after base */14#define OFS_SEVSTAT 0 /* Is 0 because fn2 base will be set at SEVSTAT */15#define POWER_BIT 2416 17struct gxp_fan_ctrl_drvdata {18 void __iomem *base;19 void __iomem *plreg;20 void __iomem *fn2;21};22 23static bool fan_installed(struct device *dev, int fan)24{25 struct gxp_fan_ctrl_drvdata *drvdata = dev_get_drvdata(dev);26 u8 val;27 28 val = readb(drvdata->plreg + OFS_FAN_INST);29 30 return !!(val & BIT(fan));31}32 33static long fan_failed(struct device *dev, int fan)34{35 struct gxp_fan_ctrl_drvdata *drvdata = dev_get_drvdata(dev);36 u8 val;37 38 val = readb(drvdata->plreg + OFS_FAN_FAIL);39 40 return !!(val & BIT(fan));41}42 43static long fan_enabled(struct device *dev, int fan)44{45 struct gxp_fan_ctrl_drvdata *drvdata = dev_get_drvdata(dev);46 u32 val;47 48 /*49 * Check the power status as if the platform is off the value50 * reported for the PWM will be incorrect. Report fan as51 * disabled.52 */53 val = readl(drvdata->fn2 + OFS_SEVSTAT);54 55 return !!((val & BIT(POWER_BIT)) && fan_installed(dev, fan));56}57 58static int gxp_pwm_write(struct device *dev, u32 attr, int channel, long val)59{60 struct gxp_fan_ctrl_drvdata *drvdata = dev_get_drvdata(dev);61 62 switch (attr) {63 case hwmon_pwm_input:64 if (val > 255 || val < 0)65 return -EINVAL;66 writeb(val, drvdata->base + channel);67 return 0;68 default:69 return -EOPNOTSUPP;70 }71}72 73static int gxp_fan_ctrl_write(struct device *dev, enum hwmon_sensor_types type,74 u32 attr, int channel, long val)75{76 switch (type) {77 case hwmon_pwm:78 return gxp_pwm_write(dev, attr, channel, val);79 default:80 return -EOPNOTSUPP;81 }82}83 84static int gxp_fan_read(struct device *dev, u32 attr, int channel, long *val)85{86 switch (attr) {87 case hwmon_fan_enable:88 *val = fan_enabled(dev, channel);89 return 0;90 case hwmon_fan_fault:91 *val = fan_failed(dev, channel);92 return 0;93 default:94 return -EOPNOTSUPP;95 }96}97 98static int gxp_pwm_read(struct device *dev, u32 attr, int channel, long *val)99{100 struct gxp_fan_ctrl_drvdata *drvdata = dev_get_drvdata(dev);101 u32 reg;102 103 /*104 * Check the power status of the platform. If the platform is off105 * the value reported for the PWM will be incorrect. In this case106 * report a PWM of zero.107 */108 109 reg = readl(drvdata->fn2 + OFS_SEVSTAT);110 111 if (reg & BIT(POWER_BIT))112 *val = fan_installed(dev, channel) ? readb(drvdata->base + channel) : 0;113 else114 *val = 0;115 116 return 0;117}118 119static int gxp_fan_ctrl_read(struct device *dev, enum hwmon_sensor_types type,120 u32 attr, int channel, long *val)121{122 switch (type) {123 case hwmon_fan:124 return gxp_fan_read(dev, attr, channel, val);125 case hwmon_pwm:126 return gxp_pwm_read(dev, attr, channel, val);127 default:128 return -EOPNOTSUPP;129 }130}131 132static umode_t gxp_fan_ctrl_is_visible(const void *_data,133 enum hwmon_sensor_types type,134 u32 attr, int channel)135{136 umode_t mode = 0;137 138 switch (type) {139 case hwmon_fan:140 switch (attr) {141 case hwmon_fan_enable:142 case hwmon_fan_fault:143 mode = 0444;144 break;145 default:146 break;147 }148 break;149 case hwmon_pwm:150 switch (attr) {151 case hwmon_pwm_input:152 mode = 0644;153 break;154 default:155 break;156 }157 break;158 default:159 break;160 }161 162 return mode;163}164 165static const struct hwmon_ops gxp_fan_ctrl_ops = {166 .is_visible = gxp_fan_ctrl_is_visible,167 .read = gxp_fan_ctrl_read,168 .write = gxp_fan_ctrl_write,169};170 171static const struct hwmon_channel_info * const gxp_fan_ctrl_info[] = {172 HWMON_CHANNEL_INFO(fan,173 HWMON_F_FAULT | HWMON_F_ENABLE,174 HWMON_F_FAULT | HWMON_F_ENABLE,175 HWMON_F_FAULT | HWMON_F_ENABLE,176 HWMON_F_FAULT | HWMON_F_ENABLE,177 HWMON_F_FAULT | HWMON_F_ENABLE,178 HWMON_F_FAULT | HWMON_F_ENABLE,179 HWMON_F_FAULT | HWMON_F_ENABLE,180 HWMON_F_FAULT | HWMON_F_ENABLE),181 HWMON_CHANNEL_INFO(pwm,182 HWMON_PWM_INPUT,183 HWMON_PWM_INPUT,184 HWMON_PWM_INPUT,185 HWMON_PWM_INPUT,186 HWMON_PWM_INPUT,187 HWMON_PWM_INPUT,188 HWMON_PWM_INPUT,189 HWMON_PWM_INPUT),190 NULL191};192 193static const struct hwmon_chip_info gxp_fan_ctrl_chip_info = {194 .ops = &gxp_fan_ctrl_ops,195 .info = gxp_fan_ctrl_info,196 197};198 199static int gxp_fan_ctrl_probe(struct platform_device *pdev)200{201 struct gxp_fan_ctrl_drvdata *drvdata;202 struct device *dev = &pdev->dev;203 struct device *hwmon_dev;204 205 drvdata = devm_kzalloc(dev, sizeof(struct gxp_fan_ctrl_drvdata),206 GFP_KERNEL);207 if (!drvdata)208 return -ENOMEM;209 210 drvdata->base = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);211 if (IS_ERR(drvdata->base))212 return dev_err_probe(dev, PTR_ERR(drvdata->base),213 "failed to map base\n");214 215 drvdata->plreg = devm_platform_ioremap_resource_byname(pdev,216 "pl");217 if (IS_ERR(drvdata->plreg))218 return dev_err_probe(dev, PTR_ERR(drvdata->plreg),219 "failed to map plreg\n");220 221 drvdata->fn2 = devm_platform_ioremap_resource_byname(pdev,222 "fn2");223 if (IS_ERR(drvdata->fn2))224 return dev_err_probe(dev, PTR_ERR(drvdata->fn2),225 "failed to map fn2\n");226 227 hwmon_dev = devm_hwmon_device_register_with_info(&pdev->dev,228 "hpe_gxp_fan_ctrl",229 drvdata,230 &gxp_fan_ctrl_chip_info,231 NULL);232 233 return PTR_ERR_OR_ZERO(hwmon_dev);234}235 236static const struct of_device_id gxp_fan_ctrl_of_match[] = {237 { .compatible = "hpe,gxp-fan-ctrl", },238 {},239};240MODULE_DEVICE_TABLE(of, gxp_fan_ctrl_of_match);241 242static struct platform_driver gxp_fan_ctrl_driver = {243 .probe = gxp_fan_ctrl_probe,244 .driver = {245 .name = "gxp-fan-ctrl",246 .of_match_table = gxp_fan_ctrl_of_match,247 },248};249module_platform_driver(gxp_fan_ctrl_driver);250 251MODULE_AUTHOR("Nick Hawkins <nick.hawkins@hpe.com>");252MODULE_DESCRIPTION("HPE GXP fan controller");253MODULE_LICENSE("GPL");254