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