1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright (C) 2023 Hewlett-Packard Enterprise Development Company, L.P. */
3
4 #include <linux/err.h>
5 #include <linux/hwmon.h>
6 #include <linux/io.h>
7 #include <linux/module.h>
8 #include <linux/platform_device.h>
9
10 struct gxp_fan_ctrl_drvdata {
11 void __iomem *base;
12 };
13
gxp_pwm_write(struct device * dev,u32 attr,int channel,long val)14 static int gxp_pwm_write(struct device *dev, u32 attr, int channel, long val)
15 {
16 struct gxp_fan_ctrl_drvdata *drvdata = dev_get_drvdata(dev);
17
18 switch (attr) {
19 case hwmon_pwm_input:
20 if (val > 255 || val < 0)
21 return -EINVAL;
22 writeb(val, drvdata->base + channel);
23 return 0;
24 default:
25 return -EOPNOTSUPP;
26 }
27 }
28
gxp_fan_ctrl_write(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long val)29 static int gxp_fan_ctrl_write(struct device *dev, enum hwmon_sensor_types type,
30 u32 attr, int channel, long val)
31 {
32 switch (type) {
33 case hwmon_pwm:
34 return gxp_pwm_write(dev, attr, channel, val);
35 default:
36 return -EOPNOTSUPP;
37 }
38 }
39
gxp_pwm_read(struct device * dev,u32 attr,int channel,long * val)40 static int gxp_pwm_read(struct device *dev, u32 attr, int channel, long *val)
41 {
42 struct gxp_fan_ctrl_drvdata *drvdata = dev_get_drvdata(dev);
43
44 *val = readb(drvdata->base + channel);
45
46 return 0;
47 }
48
gxp_fan_ctrl_read(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long * val)49 static int gxp_fan_ctrl_read(struct device *dev, enum hwmon_sensor_types type,
50 u32 attr, int channel, long *val)
51 {
52 switch (type) {
53 case hwmon_pwm:
54 return gxp_pwm_read(dev, attr, channel, val);
55 default:
56 return -EOPNOTSUPP;
57 }
58 }
59
gxp_fan_ctrl_is_visible(const void * _data,enum hwmon_sensor_types type,u32 attr,int channel)60 static umode_t gxp_fan_ctrl_is_visible(const void *_data,
61 enum hwmon_sensor_types type,
62 u32 attr, int channel)
63 {
64 umode_t mode = 0;
65
66 switch (type) {
67 case hwmon_pwm:
68 switch (attr) {
69 case hwmon_pwm_input:
70 mode = 0644;
71 break;
72 default:
73 break;
74 }
75 break;
76 default:
77 break;
78 }
79
80 return mode;
81 }
82
83 static const struct hwmon_ops gxp_fan_ctrl_ops = {
84 .is_visible = gxp_fan_ctrl_is_visible,
85 .read = gxp_fan_ctrl_read,
86 .write = gxp_fan_ctrl_write,
87 };
88
89 static const struct hwmon_channel_info * const gxp_fan_ctrl_info[] = {
90 HWMON_CHANNEL_INFO(pwm,
91 HWMON_PWM_INPUT,
92 HWMON_PWM_INPUT,
93 HWMON_PWM_INPUT,
94 HWMON_PWM_INPUT,
95 HWMON_PWM_INPUT,
96 HWMON_PWM_INPUT,
97 HWMON_PWM_INPUT,
98 HWMON_PWM_INPUT),
99 NULL
100 };
101
102 static const struct hwmon_chip_info gxp_fan_ctrl_chip_info = {
103 .ops = &gxp_fan_ctrl_ops,
104 .info = gxp_fan_ctrl_info,
105
106 };
107
gxp_fan_ctrl_probe(struct platform_device * pdev)108 static int gxp_fan_ctrl_probe(struct platform_device *pdev)
109 {
110 struct gxp_fan_ctrl_drvdata *drvdata;
111 struct device *dev = &pdev->dev;
112 struct device *hwmon_dev;
113
114 drvdata = devm_kzalloc(dev, sizeof(struct gxp_fan_ctrl_drvdata),
115 GFP_KERNEL);
116 if (!drvdata)
117 return -ENOMEM;
118
119 drvdata->base = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
120 if (IS_ERR(drvdata->base))
121 return dev_err_probe(dev, PTR_ERR(drvdata->base),
122 "failed to map base\n");
123
124 hwmon_dev = devm_hwmon_device_register_with_info(&pdev->dev,
125 "hpe_gxp_fan_ctrl",
126 drvdata,
127 &gxp_fan_ctrl_chip_info,
128 NULL);
129
130 return PTR_ERR_OR_ZERO(hwmon_dev);
131 }
132
133 static const struct of_device_id gxp_fan_ctrl_of_match[] = {
134 { .compatible = "hpe,gxp-fan-ctrl", },
135 {},
136 };
137 MODULE_DEVICE_TABLE(of, gxp_fan_ctrl_of_match);
138
139 static struct platform_driver gxp_fan_ctrl_driver = {
140 .probe = gxp_fan_ctrl_probe,
141 .driver = {
142 .name = "gxp-fan-ctrl",
143 .of_match_table = gxp_fan_ctrl_of_match,
144 },
145 };
146 module_platform_driver(gxp_fan_ctrl_driver);
147
148 MODULE_AUTHOR("Nick Hawkins <nick.hawkins@hpe.com>");
149 MODULE_DESCRIPTION("HPE GXP fan controller");
150 MODULE_LICENSE("GPL");
151