/* * 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; } #ifdef CONFIG_OF static const struct of_device_id tps65217_bl_of_match[] = { { .compatible = "ti,tps65217-bl", }, { /* sentinel */ }, }; MODULE_DEVICE_TABLE(of, tps65217_bl_of_match); #endif static struct platform_driver tps65217_bl_driver = { .probe = tps65217_bl_probe, .driver = { .name = "tps65217-bl", .of_match_table = of_match_ptr(tps65217_bl_of_match), }, }; module_platform_driver(tps65217_bl_driver); MODULE_DESCRIPTION("TPS65217 Backlight driver"); MODULE_LICENSE("GPL v2"); MODULE_AUTHOR("Matthias Kaehlcke <matthias@kaehlcke.net>");