1 files changed, 352 insertions, 0 deletions

diff --git a/drivers/video/backlight/tps65217_bl.c b/drivers/video/backlight/tps65217_bl.c
new file mode 100644
index 000000000000..6ac2ef5da32c
--- /dev/null
+++ b/drivers/video/backlight/tps65217_bl.c
@@ -0,0 +1,352 @@
+/*
+ * 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>");