diff options
Diffstat (limited to '')
-rw-r--r-- | drivers/leds/leds-wm831x-status.c | 305 |
1 files changed, 305 insertions, 0 deletions
diff --git a/drivers/leds/leds-wm831x-status.c b/drivers/leds/leds-wm831x-status.c new file mode 100644 index 000000000..c48b80574 --- /dev/null +++ b/drivers/leds/leds-wm831x-status.c @@ -0,0 +1,305 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * LED driver for WM831x status LEDs + * + * Copyright(C) 2009 Wolfson Microelectronics PLC. + */ + +#include <linux/kernel.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/leds.h> +#include <linux/err.h> +#include <linux/mfd/wm831x/core.h> +#include <linux/mfd/wm831x/pdata.h> +#include <linux/mfd/wm831x/status.h> +#include <linux/module.h> + + +struct wm831x_status { + struct led_classdev cdev; + struct wm831x *wm831x; + struct mutex mutex; + + spinlock_t value_lock; + int reg; /* Control register */ + int reg_val; /* Control register value */ + + int blink; + int blink_time; + int blink_cyc; + int src; + enum led_brightness brightness; +}; + +#define to_wm831x_status(led_cdev) \ + container_of(led_cdev, struct wm831x_status, cdev) + +static void wm831x_status_set(struct wm831x_status *led) +{ + unsigned long flags; + + mutex_lock(&led->mutex); + + led->reg_val &= ~(WM831X_LED_SRC_MASK | WM831X_LED_MODE_MASK | + WM831X_LED_DUTY_CYC_MASK | WM831X_LED_DUR_MASK); + + spin_lock_irqsave(&led->value_lock, flags); + + led->reg_val |= led->src << WM831X_LED_SRC_SHIFT; + if (led->blink) { + led->reg_val |= 2 << WM831X_LED_MODE_SHIFT; + led->reg_val |= led->blink_time << WM831X_LED_DUR_SHIFT; + led->reg_val |= led->blink_cyc; + } else { + if (led->brightness != LED_OFF) + led->reg_val |= 1 << WM831X_LED_MODE_SHIFT; + } + + spin_unlock_irqrestore(&led->value_lock, flags); + + wm831x_reg_write(led->wm831x, led->reg, led->reg_val); + + mutex_unlock(&led->mutex); +} + +static int wm831x_status_brightness_set(struct led_classdev *led_cdev, + enum led_brightness value) +{ + struct wm831x_status *led = to_wm831x_status(led_cdev); + unsigned long flags; + + spin_lock_irqsave(&led->value_lock, flags); + led->brightness = value; + if (value == LED_OFF) + led->blink = 0; + spin_unlock_irqrestore(&led->value_lock, flags); + wm831x_status_set(led); + + return 0; +} + +static int wm831x_status_blink_set(struct led_classdev *led_cdev, + unsigned long *delay_on, + unsigned long *delay_off) +{ + struct wm831x_status *led = to_wm831x_status(led_cdev); + unsigned long flags; + int ret = 0; + + /* Pick some defaults if we've not been given times */ + if (*delay_on == 0 && *delay_off == 0) { + *delay_on = 250; + *delay_off = 250; + } + + spin_lock_irqsave(&led->value_lock, flags); + + /* We only have a limited selection of settings, see if we can + * support the configuration we're being given */ + switch (*delay_on) { + case 1000: + led->blink_time = 0; + break; + case 250: + led->blink_time = 1; + break; + case 125: + led->blink_time = 2; + break; + case 62: + case 63: + /* Actually 62.5ms */ + led->blink_time = 3; + break; + default: + ret = -EINVAL; + break; + } + + if (ret == 0) { + switch (*delay_off / *delay_on) { + case 1: + led->blink_cyc = 0; + break; + case 3: + led->blink_cyc = 1; + break; + case 4: + led->blink_cyc = 2; + break; + case 8: + led->blink_cyc = 3; + break; + default: + ret = -EINVAL; + break; + } + } + + if (ret == 0) + led->blink = 1; + else + led->blink = 0; + + spin_unlock_irqrestore(&led->value_lock, flags); + wm831x_status_set(led); + + return ret; +} + +static const char * const led_src_texts[] = { + "otp", + "power", + "charger", + "soft", +}; + +static ssize_t src_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct led_classdev *led_cdev = dev_get_drvdata(dev); + struct wm831x_status *led = to_wm831x_status(led_cdev); + int i; + ssize_t ret = 0; + + mutex_lock(&led->mutex); + + for (i = 0; i < ARRAY_SIZE(led_src_texts); i++) + if (i == led->src) + ret += sprintf(&buf[ret], "[%s] ", led_src_texts[i]); + else + ret += sprintf(&buf[ret], "%s ", led_src_texts[i]); + + mutex_unlock(&led->mutex); + + ret += sprintf(&buf[ret], "\n"); + + return ret; +} + +static ssize_t src_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t size) +{ + struct led_classdev *led_cdev = dev_get_drvdata(dev); + struct wm831x_status *led = to_wm831x_status(led_cdev); + int i; + + i = sysfs_match_string(led_src_texts, buf); + if (i >= 0) { + mutex_lock(&led->mutex); + led->src = i; + mutex_unlock(&led->mutex); + wm831x_status_set(led); + } + + return size; +} + +static DEVICE_ATTR_RW(src); + +static struct attribute *wm831x_status_attrs[] = { + &dev_attr_src.attr, + NULL +}; +ATTRIBUTE_GROUPS(wm831x_status); + +static int wm831x_status_probe(struct platform_device *pdev) +{ + struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent); + struct wm831x_pdata *chip_pdata; + struct wm831x_status_pdata pdata; + struct wm831x_status *drvdata; + struct resource *res; + int id = pdev->id % ARRAY_SIZE(chip_pdata->status); + int ret; + + res = platform_get_resource(pdev, IORESOURCE_REG, 0); + if (res == NULL) { + dev_err(&pdev->dev, "No register resource\n"); + return -EINVAL; + } + + drvdata = devm_kzalloc(&pdev->dev, sizeof(struct wm831x_status), + GFP_KERNEL); + if (!drvdata) + return -ENOMEM; + + drvdata->wm831x = wm831x; + drvdata->reg = res->start; + + if (dev_get_platdata(wm831x->dev)) + chip_pdata = dev_get_platdata(wm831x->dev); + else + chip_pdata = NULL; + + memset(&pdata, 0, sizeof(pdata)); + if (chip_pdata && chip_pdata->status[id]) + memcpy(&pdata, chip_pdata->status[id], sizeof(pdata)); + else + pdata.name = dev_name(&pdev->dev); + + mutex_init(&drvdata->mutex); + spin_lock_init(&drvdata->value_lock); + + /* We cache the configuration register and read startup values + * from it. */ + drvdata->reg_val = wm831x_reg_read(wm831x, drvdata->reg); + + if (drvdata->reg_val & WM831X_LED_MODE_MASK) + drvdata->brightness = LED_FULL; + else + drvdata->brightness = LED_OFF; + + /* Set a default source if configured, otherwise leave the + * current hardware setting. + */ + if (pdata.default_src == WM831X_STATUS_PRESERVE) { + drvdata->src = drvdata->reg_val; + drvdata->src &= WM831X_LED_SRC_MASK; + drvdata->src >>= WM831X_LED_SRC_SHIFT; + } else { + drvdata->src = pdata.default_src - 1; + } + + drvdata->cdev.name = pdata.name; + drvdata->cdev.default_trigger = pdata.default_trigger; + drvdata->cdev.brightness_set_blocking = wm831x_status_brightness_set; + drvdata->cdev.blink_set = wm831x_status_blink_set; + drvdata->cdev.groups = wm831x_status_groups; + + ret = led_classdev_register(wm831x->dev, &drvdata->cdev); + if (ret < 0) { + dev_err(&pdev->dev, "Failed to register LED: %d\n", ret); + return ret; + } + + platform_set_drvdata(pdev, drvdata); + + return 0; +} + +static int wm831x_status_remove(struct platform_device *pdev) +{ + struct wm831x_status *drvdata = platform_get_drvdata(pdev); + + led_classdev_unregister(&drvdata->cdev); + + return 0; +} + +static struct platform_driver wm831x_status_driver = { + .driver = { + .name = "wm831x-status", + }, + .probe = wm831x_status_probe, + .remove = wm831x_status_remove, +}; + +module_platform_driver(wm831x_status_driver); + +MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>"); +MODULE_DESCRIPTION("WM831x status LED driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:wm831x-status"); |