--- /dev/null
+/*
+ * tps65217_bl.c
+ *
+ * TPS65217 backlight driver
+ *
+ * Copyright (C) 2012 Matthias Kaehlcke
+ * Author: Matthias Kaehlcke <matthias@kaehlcke.net>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/backlight.h>
+#include <linux/err.h>
+#include <linux/fb.h>
+#include <linux/mfd/tps65217.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+struct tps65217_bl {
+ struct tps65217 *tps;
+ struct device *dev;
+ struct backlight_device *bl;
+ bool is_enabled;
+};
+
+static int tps65217_bl_enable(struct tps65217_bl *tps65217_bl)
+{
+ int rc;
+
+ rc = tps65217_set_bits(tps65217_bl->tps, TPS65217_REG_WLEDCTRL1,
+ TPS65217_WLEDCTRL1_ISINK_ENABLE,
+ TPS65217_WLEDCTRL1_ISINK_ENABLE, TPS65217_PROTECT_NONE);
+ if (rc) {
+ dev_err(tps65217_bl->dev,
+ "failed to enable backlight: %d\n", rc);
+ return rc;
+ }
+
+ tps65217_bl->is_enabled = true;
+
+ dev_dbg(tps65217_bl->dev, "backlight enabled\n");
+
+ return 0;
+}
+
+static int tps65217_bl_disable(struct tps65217_bl *tps65217_bl)
+{
+ int rc;
+
+ rc = tps65217_clear_bits(tps65217_bl->tps,
+ TPS65217_REG_WLEDCTRL1,
+ TPS65217_WLEDCTRL1_ISINK_ENABLE,
+ TPS65217_PROTECT_NONE);
+ if (rc) {
+ dev_err(tps65217_bl->dev,
+ "failed to disable backlight: %d\n", rc);
+ return rc;
+ }
+
+ tps65217_bl->is_enabled = false;
+
+ dev_dbg(tps65217_bl->dev, "backlight disabled\n");
+
+ return 0;
+}
+
+static int tps65217_bl_update_status(struct backlight_device *bl)
+{
+ struct tps65217_bl *tps65217_bl = bl_get_data(bl);
+ int rc;
+ int brightness = bl->props.brightness;
+
+ if (bl->props.state & BL_CORE_SUSPENDED)
+ brightness = 0;
+
+ if ((bl->props.power != FB_BLANK_UNBLANK) ||
+ (bl->props.fb_blank != FB_BLANK_UNBLANK))
+ /* framebuffer in low power mode or blanking active */
+ brightness = 0;
+
+ if (brightness > 0) {
+ rc = tps65217_reg_write(tps65217_bl->tps,
+ TPS65217_REG_WLEDCTRL2,
+ brightness - 1,
+ TPS65217_PROTECT_NONE);
+ if (rc) {
+ dev_err(tps65217_bl->dev,
+ "failed to set brightness level: %d\n", rc);
+ return rc;
+ }
+
+ dev_dbg(tps65217_bl->dev, "brightness set to %d\n", brightness);
+
+ if (!tps65217_bl->is_enabled)
+ rc = tps65217_bl_enable(tps65217_bl);
+ } else {
+ rc = tps65217_bl_disable(tps65217_bl);
+ }
+
+ return rc;
+}
+
+static int tps65217_bl_get_brightness(struct backlight_device *bl)
+{
+ return bl->props.brightness;
+}
+
+static const struct backlight_ops tps65217_bl_ops = {
+ .options = BL_CORE_SUSPENDRESUME,
+ .update_status = tps65217_bl_update_status,
+ .get_brightness = tps65217_bl_get_brightness
+};
+
+static int tps65217_bl_hw_init(struct tps65217_bl *tps65217_bl,
+ struct tps65217_bl_pdata *pdata)
+{
+ int rc;
+
+ rc = tps65217_bl_disable(tps65217_bl);
+ if (rc)
+ return rc;
+
+ switch (pdata->isel) {
+ case TPS65217_BL_ISET1:
+ /* select ISET_1 current level */
+ rc = tps65217_clear_bits(tps65217_bl->tps,
+ TPS65217_REG_WLEDCTRL1,
+ TPS65217_WLEDCTRL1_ISEL,
+ TPS65217_PROTECT_NONE);
+ if (rc) {
+ dev_err(tps65217_bl->dev,
+ "failed to select ISET1 current level: %d)\n",
+ rc);
+ return rc;
+ }
+
+ dev_dbg(tps65217_bl->dev, "selected ISET1 current level\n");
+
+ break;
+
+ case TPS65217_BL_ISET2:
+ /* select ISET2 current level */
+ rc = tps65217_set_bits(tps65217_bl->tps, TPS65217_REG_WLEDCTRL1,
+ TPS65217_WLEDCTRL1_ISEL,
+ TPS65217_WLEDCTRL1_ISEL, TPS65217_PROTECT_NONE);
+ if (rc) {
+ dev_err(tps65217_bl->dev,
+ "failed to select ISET2 current level: %d\n",
+ rc);
+ return rc;
+ }
+
+ dev_dbg(tps65217_bl->dev, "selected ISET2 current level\n");
+
+ break;
+
+ default:
+ dev_err(tps65217_bl->dev,
+ "invalid value for current level: %d\n", pdata->isel);
+ return -EINVAL;
+ }
+
+ /* set PWM frequency */
+ rc = tps65217_set_bits(tps65217_bl->tps,
+ TPS65217_REG_WLEDCTRL1,
+ TPS65217_WLEDCTRL1_FDIM_MASK,
+ pdata->fdim,
+ TPS65217_PROTECT_NONE);
+ if (rc) {
+ dev_err(tps65217_bl->dev,
+ "failed to select PWM dimming frequency: %d\n",
+ rc);
+ return rc;
+ }
+
+ return 0;
+}
+
+#ifdef CONFIG_OF
+static struct tps65217_bl_pdata *
+tps65217_bl_parse_dt(struct platform_device *pdev)
+{
+ struct tps65217 *tps = dev_get_drvdata(pdev->dev.parent);
+ struct device_node *node = of_node_get(tps->dev->of_node);
+ struct tps65217_bl_pdata *pdata, *err;
+ u32 val;
+
+ node = of_find_node_by_name(node, "backlight");
+ if (!node)
+ return ERR_PTR(-ENODEV);
+
+ pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+ if (!pdata) {
+ dev_err(&pdev->dev, "failed to allocate platform data\n");
+ err = ERR_PTR(-ENOMEM);
+ goto err;
+ }
+
+ pdata->isel = TPS65217_BL_ISET1;
+ if (!of_property_read_u32(node, "isel", &val)) {
+ if (val < TPS65217_BL_ISET1 ||
+ val > TPS65217_BL_ISET2) {
+ dev_err(&pdev->dev,
+ "invalid 'isel' value in the device tree\n");
+ err = ERR_PTR(-EINVAL);
+ goto err;
+ }
+
+ pdata->isel = val;
+ }
+
+ pdata->fdim = TPS65217_BL_FDIM_200HZ;
+ if (!of_property_read_u32(node, "fdim", &val)) {
+ switch (val) {
+ case 100:
+ pdata->fdim = TPS65217_BL_FDIM_100HZ;
+ break;
+
+ case 200:
+ pdata->fdim = TPS65217_BL_FDIM_200HZ;
+ break;
+
+ case 500:
+ pdata->fdim = TPS65217_BL_FDIM_500HZ;
+ break;
+
+ case 1000:
+ pdata->fdim = TPS65217_BL_FDIM_1000HZ;
+ break;
+
+ default:
+ dev_err(&pdev->dev,
+ "invalid 'fdim' value in the device tree\n");
+ err = ERR_PTR(-EINVAL);
+ goto err;
+ }
+ }
+
+ of_node_put(node);
+
+ return pdata;
+
+err:
+ of_node_put(node);
+
+ return err;
+}
+#else
+static struct tps65217_bl_pdata *
+tps65217_bl_parse_dt(struct platform_device *pdev)
+{
+ return NULL;
+}
+#endif
+
+static int tps65217_bl_probe(struct platform_device *pdev)
+{
+ int rc;
+ struct tps65217 *tps = dev_get_drvdata(pdev->dev.parent);
+ struct tps65217_bl *tps65217_bl;
+ struct tps65217_bl_pdata *pdata;
+ struct backlight_properties bl_props;
+
+ if (tps->dev->of_node) {
+ pdata = tps65217_bl_parse_dt(pdev);
+ if (IS_ERR(pdata))
+ return PTR_ERR(pdata);
+ } else {
+ if (!pdev->dev.platform_data) {
+ dev_err(&pdev->dev, "no platform data provided\n");
+ return -EINVAL;
+ }
+
+ pdata = pdev->dev.platform_data;
+ }
+
+ tps65217_bl = devm_kzalloc(&pdev->dev, sizeof(*tps65217_bl),
+ GFP_KERNEL);
+ if (tps65217_bl == NULL) {
+ dev_err(&pdev->dev, "allocation of struct tps65217_bl failed\n");
+ return -ENOMEM;
+ }
+
+ tps65217_bl->tps = tps;
+ tps65217_bl->dev = &pdev->dev;
+ tps65217_bl->is_enabled = false;
+
+ rc = tps65217_bl_hw_init(tps65217_bl, pdata);
+ if (rc)
+ return rc;
+
+ memset(&bl_props, 0, sizeof(struct backlight_properties));
+ bl_props.type = BACKLIGHT_RAW;
+ bl_props.max_brightness = 100;
+
+ tps65217_bl->bl = backlight_device_register(pdev->name,
+ tps65217_bl->dev, tps65217_bl,
+ &tps65217_bl_ops, &bl_props);
+ if (IS_ERR(tps65217_bl->bl)) {
+ dev_err(tps65217_bl->dev,
+ "registration of backlight device failed: %d\n", rc);
+ return PTR_ERR(tps65217_bl->bl);
+ }
+
+ tps65217_bl->bl->props.brightness = 0;
+
+ return 0;
+}
+
+static int tps65217_bl_remove(struct platform_device *pdev)
+{
+ struct tps65217_bl *tps65217_bl = platform_get_drvdata(pdev);
+
+ backlight_device_unregister(tps65217_bl->bl);
+
+ return 0;
+}
+
+static struct platform_driver tps65217_bl_driver = {
+ .probe = tps65217_bl_probe,
+ .remove = tps65217_bl_remove,
+ .driver = {
+ .owner = THIS_MODULE,
+ .name = "tps65217-bl",
+ },
+};
+
+static int __init tps65217_bl_init(void)
+{
+ return platform_driver_register(&tps65217_bl_driver);
+}
+
+static void __exit tps65217_bl_exit(void)
+{
+ platform_driver_unregister(&tps65217_bl_driver);
+}
+
+module_init(tps65217_bl_init);
+module_exit(tps65217_bl_exit);
+
+MODULE_DESCRIPTION("TPS65217 Backlight driver");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Matthias Kaehlcke <matthias@kaehlcke.net>");
projects / karo-tx-linux.git / commitdiff