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 */
 36struct 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 */
 53struct 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
 59static int
 60mlxreg_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, &regval);
 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
 91access_error:
 92	mutex_unlock(&priv->access_lock);
 93
 94	return ret;
 95}
 96
 97static enum led_brightness
 98mlxreg_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, &regval);
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
134static int
135mlxreg_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
145static enum led_brightness
146mlxreg_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
153static int
154mlxreg_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
184static 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					  &regval);
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
256static 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
261	led_pdata = dev_get_platdata(&pdev->dev);
262	if (!led_pdata) {
263		dev_err(&pdev->dev, "Failed to get platform data.\n");
264		return -EINVAL;
265	}
266
267	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
268	if (!priv)
269		return -ENOMEM;
270
271	mutex_init(&priv->access_lock);
272	priv->pdev = pdev;
273	priv->pdata = led_pdata;
274
275	return mlxreg_led_config(priv);
276}
277
278static void mlxreg_led_remove(struct platform_device *pdev)
279{
280	struct mlxreg_led_priv_data *priv = dev_get_drvdata(&pdev->dev);
281
282	mutex_destroy(&priv->access_lock);
283}
284
285static struct platform_driver mlxreg_led_driver = {
286	.driver = {
287	    .name = "leds-mlxreg",
288	},
289	.probe = mlxreg_led_probe,
290	.remove_new = mlxreg_led_remove,
291};
292
293module_platform_driver(mlxreg_led_driver);
294
295MODULE_AUTHOR("Vadim Pasternak <vadimp@mellanox.com>");
296MODULE_DESCRIPTION("Mellanox LED regmap driver");
297MODULE_LICENSE("Dual BSD/GPL");
298MODULE_ALIAS("platform:leds-mlxreg");