--- /dev/null
+/*
+ * 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/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 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;
+ platform_set_drvdata(pdev, drvdata);
+
+ 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);
+ 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;
+ 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;
+ }
+
+ 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");
Code Review / kvmfornfv.git / blobdiff