1 files changed, 334 insertions, 0 deletions
diff --git a/drivers/video/backlight/tps65217_bl.c b/drivers/video/backlight/tps65217_bl.c
new file mode 100644
index 000000000..61d72bffd
--- /dev/null
+++ b/drivers/video/backlight/tps65217_bl.c
@@ -0,0 +1,334 @@
+/*
+ * 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 const struct backlight_ops tps65217_bl_ops = {
+	.options	= BL_CORE_SUSPENDRESUME,
+	.update_status	= tps65217_bl_update_status,
+};
+
+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) {
+		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;
+		}
+	}
+
+	if (!of_property_read_u32(node, "default-brightness", &val)) {
+		if (val < 0 ||
+			val > 100) {
+			dev_err(&pdev->dev,
+				"invalid 'default-brightness' value in the device tree\n");
+			err = ERR_PTR(-EINVAL);
+			goto err;
+		}
+
+		pdata->dft_brightness = val;
+	}
+
+	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 {
+		pdata = dev_get_platdata(&pdev->dev);
+		if (!pdata) {
+			dev_err(&pdev->dev, "no platform data provided\n");
+			return -EINVAL;
+		}
+	}
+
+	tps65217_bl = devm_kzalloc(&pdev->dev, sizeof(*tps65217_bl),
+				GFP_KERNEL);
+	if (tps65217_bl == NULL)
+		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 = devm_backlight_device_register(&pdev->dev, 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 = pdata->dft_brightness;
+	backlight_update_status(tps65217_bl->bl);
+	platform_set_drvdata(pdev, tps65217_bl);
+
+	return 0;
+}
+
+static struct platform_driver tps65217_bl_driver = {
+	.probe		= tps65217_bl_probe,
+	.driver		= {
+		.name	= "tps65217-bl",
+	},
+};
+
+module_platform_driver(tps65217_bl_driver);
+
+MODULE_DESCRIPTION("TPS65217 Backlight driver");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Matthias Kaehlcke <matthias@kaehlcke.net>");