| /* |
| * 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 = { |
| .owner = THIS_MODULE, |
| .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>"); |