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