--- /dev/null
+/*
+ * Backlight driver for Marvell Semiconductor 88PM8606
+ *
+ * Copyright (C) 2009 Marvell International Ltd.
+ * Haojian Zhuang <haojian.zhuang@marvell.com>
+ *
+ * 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/init.h>
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/fb.h>
+#include <linux/i2c.h>
+#include <linux/backlight.h>
+#include <linux/mfd/88pm860x.h>
+#include <linux/module.h>
+
+#define MAX_BRIGHTNESS (0xFF)
+#define MIN_BRIGHTNESS (0)
+
+#define CURRENT_BITMASK (0x1F << 1)
+
+struct pm860x_backlight_data {
+ struct pm860x_chip *chip;
+ struct i2c_client *i2c;
+ int current_brightness;
+ int port;
+ int pwm;
+ int iset;
+ int reg_duty_cycle;
+ int reg_always_on;
+ int reg_current;
+};
+
+static int backlight_power_set(struct pm860x_chip *chip, int port,
+ int on)
+{
+ int ret = -EINVAL;
+
+ switch (port) {
+ case 0:
+ ret = on ? pm8606_osc_enable(chip, WLED1_DUTY) :
+ pm8606_osc_disable(chip, WLED1_DUTY);
+ break;
+ case 1:
+ ret = on ? pm8606_osc_enable(chip, WLED2_DUTY) :
+ pm8606_osc_disable(chip, WLED2_DUTY);
+ break;
+ case 2:
+ ret = on ? pm8606_osc_enable(chip, WLED3_DUTY) :
+ pm8606_osc_disable(chip, WLED3_DUTY);
+ break;
+ }
+ return ret;
+}
+
+static int pm860x_backlight_set(struct backlight_device *bl, int brightness)
+{
+ struct pm860x_backlight_data *data = bl_get_data(bl);
+ struct pm860x_chip *chip = data->chip;
+ unsigned char value;
+ int ret;
+
+ if (brightness > MAX_BRIGHTNESS)
+ value = MAX_BRIGHTNESS;
+ else
+ value = brightness;
+
+ if (brightness)
+ backlight_power_set(chip, data->port, 1);
+
+ ret = pm860x_reg_write(data->i2c, data->reg_duty_cycle, value);
+ if (ret < 0)
+ goto out;
+
+ if ((data->current_brightness == 0) && brightness) {
+ if (data->iset) {
+ ret = pm860x_set_bits(data->i2c, data->reg_current,
+ CURRENT_BITMASK, data->iset);
+ if (ret < 0)
+ goto out;
+ }
+ if (data->pwm) {
+ ret = pm860x_set_bits(data->i2c, PM8606_PWM,
+ PM8606_PWM_FREQ_MASK, data->pwm);
+ if (ret < 0)
+ goto out;
+ }
+ if (brightness == MAX_BRIGHTNESS) {
+ /* set WLED_ON bit as 100% */
+ ret = pm860x_set_bits(data->i2c, data->reg_always_on,
+ PM8606_WLED_ON, PM8606_WLED_ON);
+ }
+ } else {
+ if (brightness == MAX_BRIGHTNESS) {
+ /* set WLED_ON bit as 100% */
+ ret = pm860x_set_bits(data->i2c, data->reg_always_on,
+ PM8606_WLED_ON, PM8606_WLED_ON);
+ } else {
+ /* clear WLED_ON bit since it's not 100% */
+ ret = pm860x_set_bits(data->i2c, data->reg_always_on,
+ PM8606_WLED_ON, 0);
+ }
+ }
+ if (ret < 0)
+ goto out;
+
+ if (brightness == 0)
+ backlight_power_set(chip, data->port, 0);
+
+ dev_dbg(chip->dev, "set brightness %d\n", value);
+ data->current_brightness = value;
+ return 0;
+out:
+ dev_dbg(chip->dev, "set brightness %d failure with return value: %d\n",
+ value, ret);
+ return ret;
+}
+
+static int pm860x_backlight_update_status(struct backlight_device *bl)
+{
+ int brightness = bl->props.brightness;
+
+ if (bl->props.power != FB_BLANK_UNBLANK)
+ brightness = 0;
+
+ if (bl->props.fb_blank != FB_BLANK_UNBLANK)
+ brightness = 0;
+
+ if (bl->props.state & BL_CORE_SUSPENDED)
+ brightness = 0;
+
+ return pm860x_backlight_set(bl, brightness);
+}
+
+static int pm860x_backlight_get_brightness(struct backlight_device *bl)
+{
+ struct pm860x_backlight_data *data = bl_get_data(bl);
+ struct pm860x_chip *chip = data->chip;
+ int ret;
+
+ ret = pm860x_reg_read(data->i2c, data->reg_duty_cycle);
+ if (ret < 0)
+ goto out;
+ data->current_brightness = ret;
+ dev_dbg(chip->dev, "get brightness %d\n", data->current_brightness);
+ return data->current_brightness;
+out:
+ return -EINVAL;
+}
+
+static const struct backlight_ops pm860x_backlight_ops = {
+ .options = BL_CORE_SUSPENDRESUME,
+ .update_status = pm860x_backlight_update_status,
+ .get_brightness = pm860x_backlight_get_brightness,
+};
+
+#ifdef CONFIG_OF
+static int pm860x_backlight_dt_init(struct platform_device *pdev,
+ struct pm860x_backlight_data *data,
+ char *name)
+{
+ struct device_node *nproot, *np;
+ int iset = 0;
+
+ nproot = of_get_child_by_name(pdev->dev.parent->of_node, "backlights");
+ if (!nproot) {
+ dev_err(&pdev->dev, "failed to find backlights node\n");
+ return -ENODEV;
+ }
+ for_each_child_of_node(nproot, np) {
+ if (!of_node_cmp(np->name, name)) {
+ of_property_read_u32(np, "marvell,88pm860x-iset",
+ &iset);
+ data->iset = PM8606_WLED_CURRENT(iset);
+ of_property_read_u32(np, "marvell,88pm860x-pwm",
+ &data->pwm);
+ break;
+ }
+ }
+ of_node_put(nproot);
+ return 0;
+}
+#else
+#define pm860x_backlight_dt_init(x, y, z) (-1)
+#endif
+
+static int pm860x_backlight_probe(struct platform_device *pdev)
+{
+ struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
+ struct pm860x_backlight_pdata *pdata = dev_get_platdata(&pdev->dev);
+ struct pm860x_backlight_data *data;
+ struct backlight_device *bl;
+ struct resource *res;
+ struct backlight_properties props;
+ char name[MFD_NAME_SIZE];
+ int ret = 0;
+
+ data = devm_kzalloc(&pdev->dev, sizeof(struct pm860x_backlight_data),
+ GFP_KERNEL);
+ if (data == NULL)
+ return -ENOMEM;
+ res = platform_get_resource_byname(pdev, IORESOURCE_REG, "duty cycle");
+ if (!res) {
+ dev_err(&pdev->dev, "No REG resource for duty cycle\n");
+ return -ENXIO;
+ }
+ data->reg_duty_cycle = res->start;
+ res = platform_get_resource_byname(pdev, IORESOURCE_REG, "always on");
+ if (!res) {
+ dev_err(&pdev->dev, "No REG resource for always on\n");
+ return -ENXIO;
+ }
+ data->reg_always_on = res->start;
+ res = platform_get_resource_byname(pdev, IORESOURCE_REG, "current");
+ if (!res) {
+ dev_err(&pdev->dev, "No REG resource for current\n");
+ return -ENXIO;
+ }
+ data->reg_current = res->start;
+
+ memset(name, 0, MFD_NAME_SIZE);
+ sprintf(name, "backlight-%d", pdev->id);
+ data->port = pdev->id;
+ data->chip = chip;
+ data->i2c = (chip->id == CHIP_PM8606) ? chip->client : chip->companion;
+ data->current_brightness = MAX_BRIGHTNESS;
+ if (pm860x_backlight_dt_init(pdev, data, name)) {
+ if (pdata) {
+ data->pwm = pdata->pwm;
+ data->iset = pdata->iset;
+ }
+ }
+
+ memset(&props, 0, sizeof(struct backlight_properties));
+ props.type = BACKLIGHT_RAW;
+ props.max_brightness = MAX_BRIGHTNESS;
+ bl = devm_backlight_device_register(&pdev->dev, name, &pdev->dev, data,
+ &pm860x_backlight_ops, &props);
+ if (IS_ERR(bl)) {
+ dev_err(&pdev->dev, "failed to register backlight\n");
+ return PTR_ERR(bl);
+ }
+ bl->props.brightness = MAX_BRIGHTNESS;
+
+ platform_set_drvdata(pdev, bl);
+
+ /* read current backlight */
+ ret = pm860x_backlight_get_brightness(bl);
+ if (ret < 0)
+ return ret;
+
+ backlight_update_status(bl);
+ return 0;
+}
+
+static struct platform_driver pm860x_backlight_driver = {
+ .driver = {
+ .name = "88pm860x-backlight",
+ },
+ .probe = pm860x_backlight_probe,
+};
+
+module_platform_driver(pm860x_backlight_driver);
+
+MODULE_DESCRIPTION("Backlight Driver for Marvell Semiconductor 88PM8606");
+MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:88pm860x-backlight");
Code Review / kvmfornfv.git / blobdiff