1 // SPDX-License-Identifier: GPL-2.0-only
2 /* 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 24
16
17 struct gxp_fan_ctrl_drvdata {
18 void __iomem *base;
19 void __iomem *plreg;
20 void __iomem *fn2;
21 };
22
fan_installed(struct device * dev,int fan)23 static 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
fan_failed(struct device * dev,int fan)33 static 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
fan_enabled(struct device * dev,int fan)43 static 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 value
50 * reported for the PWM will be incorrect. Report fan as
51 * disabled.
52 */
53 val = readl(drvdata->fn2 + OFS_SEVSTAT);
54
55 return !!((val & BIT(POWER_BIT)) && fan_installed(dev, fan));
56 }
57
gxp_pwm_write(struct device * dev,u32 attr,int channel,long val)58 static 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
gxp_fan_ctrl_write(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long val)73 static 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
gxp_fan_read(struct device * dev,u32 attr,int channel,long * val)84 static 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
gxp_pwm_read(struct device * dev,u32 attr,int channel,long * val)98 static 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 off
105 * the value reported for the PWM will be incorrect. In this case
106 * 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 else
114 *val = 0;
115
116 return 0;
117 }
118
gxp_fan_ctrl_read(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long * val)119 static 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
gxp_fan_ctrl_is_visible(const void * _data,enum hwmon_sensor_types type,u32 attr,int channel)132 static 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
165 static 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
171 static 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 NULL
191 };
192
193 static 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
gxp_fan_ctrl_probe(struct platform_device * pdev)199 static 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
236 static const struct of_device_id gxp_fan_ctrl_of_match[] = {
237 { .compatible = "hpe,gxp-fan-ctrl", },
238 {},
239 };
240 MODULE_DEVICE_TABLE(of, gxp_fan_ctrl_of_match);
241
242 static 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 };
249 module_platform_driver(gxp_fan_ctrl_driver);
250
251 MODULE_AUTHOR("Nick Hawkins <nick.hawkins@hpe.com>");
252 MODULE_DESCRIPTION("HPE GXP fan controller");
253 MODULE_LICENSE("GPL");
254