1 // SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
2 //
3 // Copyright (c) 2018 Mellanox Technologies. All rights reserved.
4 // Copyright (c) 2018 Vadim Pasternak <vadimp@mellanox.com>
5
6 #include <linux/bitops.h>
7 #include <linux/device.h>
8 #include <linux/io.h>
9 #include <linux/leds.h>
10 #include <linux/module.h>
11 #include <linux/of_device.h>
12 #include <linux/platform_data/mlxreg.h>
13 #include <linux/platform_device.h>
14 #include <linux/regmap.h>
15
16 /* Codes for LEDs. */
17 #define MLXREG_LED_OFFSET_BLINK_3HZ 0x01 /* Offset from solid: 3Hz blink */
18 #define MLXREG_LED_OFFSET_BLINK_6HZ 0x02 /* Offset from solid: 6Hz blink */
19 #define MLXREG_LED_IS_OFF 0x00 /* Off */
20 #define MLXREG_LED_RED_SOLID 0x05 /* Solid red */
21 #define MLXREG_LED_GREEN_SOLID 0x0D /* Solid green */
22 #define MLXREG_LED_AMBER_SOLID 0x09 /* Solid amber */
23 #define MLXREG_LED_BLINK_3HZ 167 /* ~167 msec off/on - HW support */
24 #define MLXREG_LED_BLINK_6HZ 83 /* ~83 msec off/on - HW support */
25 #define MLXREG_LED_CAPABILITY_CLEAR GENMASK(31, 8) /* Clear mask */
26
27 /**
28 * struct mlxreg_led_data - led control data:
29 *
30 * @data: led configuration data;
31 * @led_cdev: led class data;
32 * @base_color: base led color (other colors have constant offset from base);
33 * @led_data: led data;
34 * @data_parent: pointer to private device control data of parent;
35 * @led_cdev_name: class device name
36 */
37 struct mlxreg_led_data {
38 struct mlxreg_core_data *data;
39 struct led_classdev led_cdev;
40 u8 base_color;
41 void *data_parent;
42 char led_cdev_name[MLXREG_CORE_LABEL_MAX_SIZE];
43 };
44
45 #define cdev_to_priv(c) container_of(c, struct mlxreg_led_data, led_cdev)
46
47 /**
48 * struct mlxreg_led_priv_data - platform private data:
49 *
50 * @pdev: platform device;
51 * @pdata: platform data;
52 * @access_lock: mutex for attribute IO access;
53 */
54 struct mlxreg_led_priv_data {
55 struct platform_device *pdev;
56 struct mlxreg_core_platform_data *pdata;
57 struct mutex access_lock; /* protect IO operations */
58 };
59
60 static int
mlxreg_led_store_hw(struct mlxreg_led_data * led_data,u8 vset)61 mlxreg_led_store_hw(struct mlxreg_led_data *led_data, u8 vset)
62 {
63 struct mlxreg_led_priv_data *priv = led_data->data_parent;
64 struct mlxreg_core_platform_data *led_pdata = priv->pdata;
65 struct mlxreg_core_data *data = led_data->data;
66 u32 regval;
67 u32 nib;
68 int ret;
69
70 /*
71 * Each LED is controlled through low or high nibble of the relevant
72 * register byte. Register offset is specified by off parameter.
73 * Parameter vset provides color code: 0x0 for off, 0x5 for solid red,
74 * 0x6 for 3Hz blink red, 0xd for solid green, 0xe for 3Hz blink
75 * green.
76 * Parameter mask specifies which nibble is used for specific LED: mask
77 * 0xf0 - lower nibble is to be used (bits from 0 to 3), mask 0x0f -
78 * higher nibble (bits from 4 to 7).
79 */
80 mutex_lock(&priv->access_lock);
81
82 ret = regmap_read(led_pdata->regmap, data->reg, ®val);
83 if (ret)
84 goto access_error;
85
86 nib = (ror32(data->mask, data->bit) == 0xf0) ? rol32(vset, data->bit) :
87 rol32(vset, data->bit + 4);
88 regval = (regval & data->mask) | nib;
89
90 ret = regmap_write(led_pdata->regmap, data->reg, regval);
91
92 access_error:
93 mutex_unlock(&priv->access_lock);
94
95 return ret;
96 }
97
98 static enum led_brightness
mlxreg_led_get_hw(struct mlxreg_led_data * led_data)99 mlxreg_led_get_hw(struct mlxreg_led_data *led_data)
100 {
101 struct mlxreg_led_priv_data *priv = led_data->data_parent;
102 struct mlxreg_core_platform_data *led_pdata = priv->pdata;
103 struct mlxreg_core_data *data = led_data->data;
104 u32 regval;
105 int err;
106
107 /*
108 * Each LED is controlled through low or high nibble of the relevant
109 * register byte. Register offset is specified by off parameter.
110 * Parameter vset provides color code: 0x0 for off, 0x5 for solid red,
111 * 0x6 for 3Hz blink red, 0xd for solid green, 0xe for 3Hz blink
112 * green.
113 * Parameter mask specifies which nibble is used for specific LED: mask
114 * 0xf0 - lower nibble is to be used (bits from 0 to 3), mask 0x0f -
115 * higher nibble (bits from 4 to 7).
116 */
117 err = regmap_read(led_pdata->regmap, data->reg, ®val);
118 if (err < 0) {
119 dev_warn(led_data->led_cdev.dev, "Failed to get current brightness, error: %d\n",
120 err);
121 /* Assume the LED is OFF */
122 return LED_OFF;
123 }
124
125 regval = regval & ~data->mask;
126 regval = (ror32(data->mask, data->bit) == 0xf0) ? ror32(regval,
127 data->bit) : ror32(regval, data->bit + 4);
128 if (regval >= led_data->base_color &&
129 regval <= (led_data->base_color + MLXREG_LED_OFFSET_BLINK_6HZ))
130 return LED_FULL;
131
132 return LED_OFF;
133 }
134
135 static int
mlxreg_led_brightness_set(struct led_classdev * cled,enum led_brightness value)136 mlxreg_led_brightness_set(struct led_classdev *cled, enum led_brightness value)
137 {
138 struct mlxreg_led_data *led_data = cdev_to_priv(cled);
139
140 if (value)
141 return mlxreg_led_store_hw(led_data, led_data->base_color);
142 else
143 return mlxreg_led_store_hw(led_data, MLXREG_LED_IS_OFF);
144 }
145
146 static enum led_brightness
mlxreg_led_brightness_get(struct led_classdev * cled)147 mlxreg_led_brightness_get(struct led_classdev *cled)
148 {
149 struct mlxreg_led_data *led_data = cdev_to_priv(cled);
150
151 return mlxreg_led_get_hw(led_data);
152 }
153
154 static int
mlxreg_led_blink_set(struct led_classdev * cled,unsigned long * delay_on,unsigned long * delay_off)155 mlxreg_led_blink_set(struct led_classdev *cled, unsigned long *delay_on,
156 unsigned long *delay_off)
157 {
158 struct mlxreg_led_data *led_data = cdev_to_priv(cled);
159 int err;
160
161 /*
162 * HW supports two types of blinking: full (6Hz) and half (3Hz).
163 * For delay on/off zero LED is setting to solid color. For others
164 * combination blinking is to be controlled by the software timer.
165 */
166 if (!(*delay_on == 0 && *delay_off == 0) &&
167 !(*delay_on == MLXREG_LED_BLINK_3HZ &&
168 *delay_off == MLXREG_LED_BLINK_3HZ) &&
169 !(*delay_on == MLXREG_LED_BLINK_6HZ &&
170 *delay_off == MLXREG_LED_BLINK_6HZ))
171 return -EINVAL;
172
173 if (*delay_on == MLXREG_LED_BLINK_6HZ)
174 err = mlxreg_led_store_hw(led_data, led_data->base_color +
175 MLXREG_LED_OFFSET_BLINK_6HZ);
176 else if (*delay_on == MLXREG_LED_BLINK_3HZ)
177 err = mlxreg_led_store_hw(led_data, led_data->base_color +
178 MLXREG_LED_OFFSET_BLINK_3HZ);
179 else
180 err = mlxreg_led_store_hw(led_data, led_data->base_color);
181
182 return err;
183 }
184
mlxreg_led_config(struct mlxreg_led_priv_data * priv)185 static int mlxreg_led_config(struct mlxreg_led_priv_data *priv)
186 {
187 struct mlxreg_core_platform_data *led_pdata = priv->pdata;
188 struct mlxreg_core_data *data = led_pdata->data;
189 struct mlxreg_led_data *led_data;
190 struct led_classdev *led_cdev;
191 enum led_brightness brightness;
192 u32 regval;
193 int i;
194 int err;
195
196 for (i = 0; i < led_pdata->counter; i++, data++) {
197 led_data = devm_kzalloc(&priv->pdev->dev, sizeof(*led_data),
198 GFP_KERNEL);
199 if (!led_data)
200 return -ENOMEM;
201
202 if (data->capability) {
203 err = regmap_read(led_pdata->regmap, data->capability,
204 ®val);
205 if (err) {
206 dev_err(&priv->pdev->dev, "Failed to query capability register\n");
207 return err;
208 }
209 if (!(regval & data->bit))
210 continue;
211 /*
212 * Field "bit" can contain one capability bit in 0 byte
213 * and offset bit in 1-3 bytes. Clear capability bit and
214 * keep only offset bit.
215 */
216 data->bit &= MLXREG_LED_CAPABILITY_CLEAR;
217 }
218
219 led_cdev = &led_data->led_cdev;
220 led_data->data_parent = priv;
221 if (strstr(data->label, "red") ||
222 strstr(data->label, "orange")) {
223 brightness = LED_OFF;
224 led_data->base_color = MLXREG_LED_RED_SOLID;
225 } else if (strstr(data->label, "amber")) {
226 brightness = LED_OFF;
227 led_data->base_color = MLXREG_LED_AMBER_SOLID;
228 } else {
229 brightness = LED_OFF;
230 led_data->base_color = MLXREG_LED_GREEN_SOLID;
231 }
232 snprintf(led_data->led_cdev_name, sizeof(led_data->led_cdev_name),
233 "mlxreg:%s", data->label);
234 led_cdev->name = led_data->led_cdev_name;
235 led_cdev->brightness = brightness;
236 led_cdev->max_brightness = LED_ON;
237 led_cdev->brightness_set_blocking =
238 mlxreg_led_brightness_set;
239 led_cdev->brightness_get = mlxreg_led_brightness_get;
240 led_cdev->blink_set = mlxreg_led_blink_set;
241 led_cdev->flags = LED_CORE_SUSPENDRESUME;
242 led_data->data = data;
243 err = devm_led_classdev_register(&priv->pdev->dev, led_cdev);
244 if (err)
245 return err;
246
247 if (led_cdev->brightness)
248 mlxreg_led_brightness_set(led_cdev,
249 led_cdev->brightness);
250 dev_info(led_cdev->dev, "label: %s, mask: 0x%02x, offset:0x%02x\n",
251 data->label, data->mask, data->reg);
252 }
253
254 return 0;
255 }
256
mlxreg_led_probe(struct platform_device * pdev)257 static int mlxreg_led_probe(struct platform_device *pdev)
258 {
259 struct mlxreg_core_platform_data *led_pdata;
260 struct mlxreg_led_priv_data *priv;
261
262 led_pdata = dev_get_platdata(&pdev->dev);
263 if (!led_pdata) {
264 dev_err(&pdev->dev, "Failed to get platform data.\n");
265 return -EINVAL;
266 }
267
268 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
269 if (!priv)
270 return -ENOMEM;
271
272 mutex_init(&priv->access_lock);
273 priv->pdev = pdev;
274 priv->pdata = led_pdata;
275
276 return mlxreg_led_config(priv);
277 }
278
mlxreg_led_remove(struct platform_device * pdev)279 static int mlxreg_led_remove(struct platform_device *pdev)
280 {
281 struct mlxreg_led_priv_data *priv = dev_get_drvdata(&pdev->dev);
282
283 mutex_destroy(&priv->access_lock);
284
285 return 0;
286 }
287
288 static struct platform_driver mlxreg_led_driver = {
289 .driver = {
290 .name = "leds-mlxreg",
291 },
292 .probe = mlxreg_led_probe,
293 .remove = mlxreg_led_remove,
294 };
295
296 module_platform_driver(mlxreg_led_driver);
297
298 MODULE_AUTHOR("Vadim Pasternak <vadimp@mellanox.com>");
299 MODULE_DESCRIPTION("Mellanox LED regmap driver");
300 MODULE_LICENSE("Dual BSD/GPL");
301 MODULE_ALIAS("platform:leds-mlxreg");
302