1// SPDX-License-Identifier: GPL-2.0
  2//
  3// Copyright (c) 2011 Samsung Electronics Co., Ltd.
  4//              http://www.samsung.com
  5//
  6// Common infrastructure for PWM Backlight for Samsung boards
  7
  8#include <linux/gpio.h>
  9#include <linux/platform_device.h>
 10#include <linux/slab.h>
 11#include <linux/io.h>
 12#include <linux/pwm_backlight.h>
 13
 14#include <plat/devs.h>
 15#include <plat/gpio-cfg.h>
 16
 17#include "backlight.h"
 18
 19struct samsung_bl_drvdata {
 20	struct platform_pwm_backlight_data plat_data;
 21	struct samsung_bl_gpio_info *gpio_info;
 22};
 23
 24static int samsung_bl_init(struct device *dev)
 25{
 26	int ret = 0;
 27	struct platform_pwm_backlight_data *pdata = dev->platform_data;
 28	struct samsung_bl_drvdata *drvdata = container_of(pdata,
 29					struct samsung_bl_drvdata, plat_data);
 30	struct samsung_bl_gpio_info *bl_gpio_info = drvdata->gpio_info;
 31
 32	ret = gpio_request(bl_gpio_info->no, "Backlight");
 33	if (ret) {
 34		printk(KERN_ERR "failed to request GPIO for LCD Backlight\n");
 35		return ret;
 36	}
 37
 38	/* Configure GPIO pin with specific GPIO function for PWM timer */
 39	s3c_gpio_cfgpin(bl_gpio_info->no, bl_gpio_info->func);
 40
 41	return 0;
 42}
 43
 44static void samsung_bl_exit(struct device *dev)
 45{
 46	struct platform_pwm_backlight_data *pdata = dev->platform_data;
 47	struct samsung_bl_drvdata *drvdata = container_of(pdata,
 48					struct samsung_bl_drvdata, plat_data);
 49	struct samsung_bl_gpio_info *bl_gpio_info = drvdata->gpio_info;
 50
 51	s3c_gpio_cfgpin(bl_gpio_info->no, S3C_GPIO_OUTPUT);
 52	gpio_free(bl_gpio_info->no);
 53}
 54
 55/* Initialize few important fields of platform_pwm_backlight_data
 56 * structure with default values. These fields can be overridden by
 57 * board-specific values sent from machine file.
 58 * For ease of operation, these fields are initialized with values
 59 * used by most samsung boards.
 60 * Users has the option of sending info about other parameters
 61 * for their specific boards
 62 */
 63
 64static struct samsung_bl_drvdata samsung_dfl_bl_data __initdata = {
 65	.plat_data = {
 66		.max_brightness = 255,
 67		.dft_brightness = 255,
 68		.enable_gpio    = -1,
 69		.init           = samsung_bl_init,
 70		.exit           = samsung_bl_exit,
 71	},
 72};
 73
 74static struct platform_device samsung_dfl_bl_device __initdata = {
 75	.name		= "pwm-backlight",
 76};
 77
 78/* samsung_bl_set - Set board specific data (if any) provided by user for
 79 * PWM Backlight control and register specific PWM and backlight device.
 80 * @gpio_info:	structure containing GPIO info for PWM timer
 81 * @bl_data:	structure containing Backlight control data
 82 */
 83void __init samsung_bl_set(struct samsung_bl_gpio_info *gpio_info,
 84	struct platform_pwm_backlight_data *bl_data)
 85{
 86	int ret = 0;
 87	struct platform_device *samsung_bl_device;
 88	struct samsung_bl_drvdata *samsung_bl_drvdata;
 89	struct platform_pwm_backlight_data *samsung_bl_data;
 90
 91	samsung_bl_device = kmemdup(&samsung_dfl_bl_device,
 92			sizeof(struct platform_device), GFP_KERNEL);
 93	if (!samsung_bl_device)
 94		return;
 95
 96	samsung_bl_drvdata = kmemdup(&samsung_dfl_bl_data,
 97				sizeof(samsung_dfl_bl_data), GFP_KERNEL);
 98	if (!samsung_bl_drvdata)
 99		goto err_data;
100
101	samsung_bl_device->dev.platform_data = &samsung_bl_drvdata->plat_data;
102	samsung_bl_drvdata->gpio_info = gpio_info;
103	samsung_bl_data = &samsung_bl_drvdata->plat_data;
104
105	/* Copy board specific data provided by user */
106	samsung_bl_device->dev.parent = &samsung_device_pwm.dev;
107
108	if (bl_data->max_brightness)
109		samsung_bl_data->max_brightness = bl_data->max_brightness;
110	if (bl_data->dft_brightness)
111		samsung_bl_data->dft_brightness = bl_data->dft_brightness;
112	if (bl_data->lth_brightness)
113		samsung_bl_data->lth_brightness = bl_data->lth_brightness;
114	if (bl_data->enable_gpio >= 0)
115		samsung_bl_data->enable_gpio = bl_data->enable_gpio;
116	if (bl_data->init)
117		samsung_bl_data->init = bl_data->init;
118	if (bl_data->notify)
119		samsung_bl_data->notify = bl_data->notify;
120	if (bl_data->notify_after)
121		samsung_bl_data->notify_after = bl_data->notify_after;
122	if (bl_data->exit)
123		samsung_bl_data->exit = bl_data->exit;
124	if (bl_data->check_fb)
125		samsung_bl_data->check_fb = bl_data->check_fb;
126
127	/* Register the Backlight dev */
128	ret = platform_device_register(samsung_bl_device);
129	if (ret) {
130		printk(KERN_ERR "failed to register backlight device: %d\n", ret);
131		goto err_plat_reg2;
132	}
133
134	return;
135
136err_plat_reg2:
137	kfree(samsung_bl_data);
138err_data:
139	kfree(samsung_bl_device);
140}