aboutsummaryrefslogtreecommitdiff
path: root/drivers/leds/leds-mlxreg.c
blob: b7855c93bd72507d78a2777411011bc0334b9d72 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
//
// Copyright (c) 2018 Mellanox Technologies. All rights reserved.
// Copyright (c) 2018 Vadim Pasternak <vadimp@mellanox.com>

#include <linux/bitops.h>
#include <linux/device.h>
#include <linux/io.h>
#include <linux/leds.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/platform_data/mlxreg.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>

/* Codes for LEDs. */
#define MLXREG_LED_OFFSET_BLINK_3HZ	0x01 /* Offset from solid: 3Hz blink */
#define MLXREG_LED_OFFSET_BLINK_6HZ	0x02 /* Offset from solid: 6Hz blink */
#define MLXREG_LED_IS_OFF		0x00 /* Off */
#define MLXREG_LED_RED_SOLID		0x05 /* Solid red */
#define MLXREG_LED_GREEN_SOLID		0x0D /* Solid green */
#define MLXREG_LED_AMBER_SOLID		0x09 /* Solid amber */
#define MLXREG_LED_BLINK_3HZ		167 /* ~167 msec off/on - HW support */
#define MLXREG_LED_BLINK_6HZ		83 /* ~83 msec off/on - HW support */
#define MLXREG_LED_CAPABILITY_CLEAR	GENMASK(31, 8) /* Clear mask */

/**
 * struct mlxreg_led_data - led control data:
 *
 * @data: led configuration data;
 * @led_cdev: led class data;
 * @base_color: base led color (other colors have constant offset from base);
 * @led_data: led data;
 * @data_parent: pointer to private device control data of parent;
 * @led_cdev_name: class device name
 */
struct mlxreg_led_data {
	struct mlxreg_core_data *data;
	struct led_classdev led_cdev;
	u8 base_color;
	void *data_parent;
	char led_cdev_name[MLXREG_CORE_LABEL_MAX_SIZE];
};

#define cdev_to_priv(c) container_of(c, struct mlxreg_led_data, led_cdev)

/**
 * struct mlxreg_led_priv_data - platform private data:
 *
 * @pdev: platform device;
 * @pdata: platform data;
 * @access_lock: mutex for attribute IO access;
 */
struct mlxreg_led_priv_data {
	struct platform_device *pdev;
	struct mlxreg_core_platform_data *pdata;
	struct mutex access_lock; /* protect IO operations */
};

static int
mlxreg_led_store_hw(struct mlxreg_led_data *led_data, u8 vset)
{
	struct mlxreg_led_priv_data *priv = led_data->data_parent;
	struct mlxreg_core_platform_data *led_pdata = priv->pdata;
	struct mlxreg_core_data *data = led_data->data;
	u32 regval;
	u32 nib;
	int ret;

	/*
	 * Each LED is controlled through low or high nibble of the relevant
	 * register byte. Register offset is specified by off parameter.
	 * Parameter vset provides color code: 0x0 for off, 0x5 for solid red,
	 * 0x6 for 3Hz blink red, 0xd for solid green, 0xe for 3Hz blink
	 * green.
	 * Parameter mask specifies which nibble is used for specific LED: mask
	 * 0xf0 - lower nibble is to be used (bits from 0 to 3), mask 0x0f -
	 * higher nibble (bits from 4 to 7).
	 */
	mutex_lock(&priv->access_lock);

	ret = regmap_read(led_pdata->regmap, data->reg, &regval);
	if (ret)
		goto access_error;

	nib = (ror32(data->mask, data->bit) == 0xf0) ? rol32(vset, data->bit) :
	      rol32(vset, data->bit + 4);
	regval = (regval & data->mask) | nib;

	ret = regmap_write(led_pdata->regmap, data->reg, regval);

access_error:
	mutex_unlock(&priv->access_lock);

	return ret;
}

static enum led_brightness
mlxreg_led_get_hw(struct mlxreg_led_data *led_data)
{
	struct mlxreg_led_priv_data *priv = led_data->data_parent;
	struct mlxreg_core_platform_data *led_pdata = priv->pdata;
	struct mlxreg_core_data *data = led_data->data;
	u32 regval;
	int err;

	/*
	 * Each LED is controlled through low or high nibble of the relevant
	 * register byte. Register offset is specified by off parameter.
	 * Parameter vset provides color code: 0x0 for off, 0x5 for solid red,
	 * 0x6 for 3Hz blink red, 0xd for solid green, 0xe for 3Hz blink
	 * green.
	 * Parameter mask specifies which nibble is used for specific LED: mask
	 * 0xf0 - lower nibble is to be used (bits from 0 to 3), mask 0x0f -
	 * higher nibble (bits from 4 to 7).
	 */
	err = regmap_read(led_pdata->regmap, data->reg, &regval);
	if (err < 0) {
		dev_warn(led_data->led_cdev.dev, "Failed to get current brightness, error: %d\n",
			 err);
		/* Assume the LED is OFF */
		return LED_OFF;
	}

	regval = regval & ~data->mask;
	regval = (ror32(data->mask, data->bit) == 0xf0) ? ror32(regval,
		 data->bit) : ror32(regval, data->bit + 4);
	if (regval >= led_data->base_color &&
	    regval <= (led_data->base_color + MLXREG_LED_OFFSET_BLINK_6HZ))
		return LED_FULL;

	return LED_OFF;
}

static int
mlxreg_led_brightness_set(struct led_classdev *cled, enum led_brightness value)
{
	struct mlxreg_led_data *led_data = cdev_to_priv(cled);

	if (value)
		return mlxreg_led_store_hw(led_data, led_data->base_color);
	else
		return mlxreg_led_store_hw(led_data, MLXREG_LED_IS_OFF);
}

static enum led_brightness
mlxreg_led_brightness_get(struct led_classdev *cled)
{
	struct mlxreg_led_data *led_data = cdev_to_priv(cled);

	return mlxreg_led_get_hw(led_data);
}

static int
mlxreg_led_blink_set(struct led_classdev *cled, unsigned long *delay_on,
		     unsigned long *delay_off)
{
	struct mlxreg_led_data *led_data = cdev_to_priv(cled);
	int err;

	/*
	 * HW supports two types of blinking: full (6Hz) and half (3Hz).
	 * For delay on/off zero LED is setting to solid color. For others
	 * combination blinking is to be controlled by the software timer.
	 */
	if (!(*delay_on == 0 && *delay_off == 0) &&
	    !(*delay_on == MLXREG_LED_BLINK_3HZ &&
	      *delay_off == MLXREG_LED_BLINK_3HZ) &&
	    !(*delay_on == MLXREG_LED_BLINK_6HZ &&
	      *delay_off == MLXREG_LED_BLINK_6HZ))
		return -EINVAL;

	if (*delay_on == MLXREG_LED_BLINK_6HZ)
		err = mlxreg_led_store_hw(led_data, led_data->base_color +
					  MLXREG_LED_OFFSET_BLINK_6HZ);
	else if (*delay_on == MLXREG_LED_BLINK_3HZ)
		err = mlxreg_led_store_hw(led_data, led_data->base_color +
					  MLXREG_LED_OFFSET_BLINK_3HZ);
	else
		err = mlxreg_led_store_hw(led_data, led_data->base_color);

	return err;
}

static int mlxreg_led_config(struct mlxreg_led_priv_data *priv)
{
	struct mlxreg_core_platform_data *led_pdata = priv->pdata;
	struct mlxreg_core_data *data = led_pdata->data;
	struct mlxreg_led_data *led_data;
	struct led_classdev *led_cdev;
	enum led_brightness brightness;
	u32 regval;
	int i;
	int err;

	for (i = 0; i < led_pdata->counter; i++, data++) {
		led_data = devm_kzalloc(&priv->pdev->dev, sizeof(*led_data),
					GFP_KERNEL);
		if (!led_data)
			return -ENOMEM;

		if (data->capability) {
			err = regmap_read(led_pdata->regmap, data->capability,
					  &regval);
			if (err) {
				dev_err(&priv->pdev->dev, "Failed to query capability register\n");
				return err;
			}
			if (!(regval & data->bit))
				continue;
			/*
			 * Field "bit" can contain one capability bit in 0 byte
			 * and offset bit in 1-3 bytes. Clear capability bit and
			 * keep only offset bit.
			 */
			data->bit &= MLXREG_LED_CAPABILITY_CLEAR;
		}

		led_cdev = &led_data->led_cdev;
		led_data->data_parent = priv;
		if (strstr(data->label, "red") ||
		    strstr(data->label, "orange")) {
			brightness = LED_OFF;
			led_data->base_color = MLXREG_LED_RED_SOLID;
		} else if (strstr(data->label, "amber")) {
			brightness = LED_OFF;
			led_data->base_color = MLXREG_LED_AMBER_SOLID;
		} else {
			brightness = LED_OFF;
			led_data->base_color = MLXREG_LED_GREEN_SOLID;
		}
		snprintf(led_data->led_cdev_name, sizeof(led_data->led_cdev_name),
			 "mlxreg:%s", data->label);
		led_cdev->name = led_data->led_cdev_name;
		led_cdev->brightness = brightness;
		led_cdev->max_brightness = LED_ON;
		led_cdev->brightness_set_blocking =
						mlxreg_led_brightness_set;
		led_cdev->brightness_get = mlxreg_led_brightness_get;
		led_cdev->blink_set = mlxreg_led_blink_set;
		led_cdev->flags = LED_CORE_SUSPENDRESUME;
		led_data->data = data;
		err = devm_led_classdev_register(&priv->pdev->dev, led_cdev);
		if (err)
			return err;

		if (led_cdev->brightness)
			mlxreg_led_brightness_set(led_cdev,
						  led_cdev->brightness);
		dev_info(led_cdev->dev, "label: %s, mask: 0x%02x, offset:0x%02x\n",
			 data->label, data->mask, data->reg);
	}

	return 0;
}

static int mlxreg_led_probe(struct platform_device *pdev)
{
	struct mlxreg_core_platform_data *led_pdata;
	struct mlxreg_led_priv_data *priv;

	led_pdata = dev_get_platdata(&pdev->dev);
	if (!led_pdata) {
		dev_err(&pdev->dev, "Failed to get platform data.\n");
		return -EINVAL;
	}

	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;

	mutex_init(&priv->access_lock);
	priv->pdev = pdev;
	priv->pdata = led_pdata;

	return mlxreg_led_config(priv);
}

static int mlxreg_led_remove(struct platform_device *pdev)
{
	struct mlxreg_led_priv_data *priv = dev_get_drvdata(&pdev->dev);

	mutex_destroy(&priv->access_lock);

	return 0;
}

static struct platform_driver mlxreg_led_driver = {
	.driver = {
	    .name = "leds-mlxreg",
	},
	.probe = mlxreg_led_probe,
	.remove = mlxreg_led_remove,
};

module_platform_driver(mlxreg_led_driver);

MODULE_AUTHOR("Vadim Pasternak <vadimp@mellanox.com>");
MODULE_DESCRIPTION("Mellanox LED regmap driver");
MODULE_LICENSE("Dual BSD/GPL");
MODULE_ALIAS("platform:leds-mlxreg");