diff options
Diffstat (limited to 'drivers/leds/leds-mlxreg.c')
| -rw-r--r-- | drivers/leds/leds-mlxreg.c | 301 |
1 files changed, 301 insertions, 0 deletions
diff --git a/drivers/leds/leds-mlxreg.c b/drivers/leds/leds-mlxreg.c new file mode 100644 index 000000000..b7855c93b --- /dev/null +++ b/drivers/leds/leds-mlxreg.c @@ -0,0 +1,301 @@ +// 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, ®val); + 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, ®val); + 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, + ®val); + 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"); |