/* * LED driver for WM831x status LEDs * * Copyright(C) 2009 Wolfson Microelectronics PLC. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * */ #include <linux/kernel.h> #include <linux/init.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 work_struct work; 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_work(struct work_struct *work) { struct wm831x_status *led = container_of(work, struct wm831x_status, work); 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 void wm831x_status_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; schedule_work(&led->work); spin_unlock_irqrestore(&led->value_lock, flags); } 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; /* Always update; if we fail turn off blinking since we expect * a software fallback. */ schedule_work(&led->work); spin_unlock_irqrestore(&led->value_lock, flags); return ret; } static const char * const led_src_texts[] = { "otp", "power", "charger", "soft", }; static ssize_t wm831x_status_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 wm831x_status_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); char name[20]; int i; size_t len; name[sizeof(name) - 1] = '\0'; strncpy(name, buf, sizeof(name) - 1); len = strlen(name); if (len && name[len - 1] == '\n') name[len - 1] = '\0'; for (i = 0; i < ARRAY_SIZE(led_src_texts); i++) { if (!strcmp(name, led_src_texts[i])) { mutex_lock(&led->mutex); led->src = i; schedule_work(&led->work); mutex_unlock(&led->mutex); } } return size; } static DEVICE_ATTR(src, 0644, wm831x_status_src_show, wm831x_status_src_store); 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_IO, 0); if (res == NULL) { dev_err(&pdev->dev, "No I/O resource\n"); ret = -EINVAL; goto err; } drvdata = devm_kzalloc(&pdev->dev, sizeof(struct wm831x_status), GFP_KERNEL); if (!drvdata) return -ENOMEM; platform_set_drvdata(pdev, drvdata); drvdata->wm831x = wm831x; drvdata->reg = res->start; if (wm831x->dev->platform_data) chip_pdata = wm831x->dev->platform_data; 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); INIT_WORK(&drvdata->work, wm831x_status_work); 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 = wm831x_status_set; drvdata->cdev.blink_set = wm831x_status_blink_set; ret = led_classdev_register(wm831x->dev, &drvdata->cdev); if (ret < 0) { dev_err(&pdev->dev, "Failed to register LED: %d\n", ret); goto err_led; } ret = device_create_file(drvdata->cdev.dev, &dev_attr_src); if (ret != 0) dev_err(&pdev->dev, "No source control for LED: %d\n", ret); return 0; err_led: led_classdev_unregister(&drvdata->cdev); err: return ret; } static int wm831x_status_remove(struct platform_device *pdev) { struct wm831x_status *drvdata = platform_get_drvdata(pdev); device_remove_file(drvdata->cdev.dev, &dev_attr_src); led_classdev_unregister(&drvdata->cdev); return 0; } static struct platform_driver wm831x_status_driver = { .driver = { .name = "wm831x-status", .owner = THIS_MODULE, }, .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");