video/backlight/pandora_bl.c

1 // SPDX-License-Identifier: GPL-2.0-only
3  * Backlight driver for Pandora handheld.
4  * Pandora uses TWL4030 PWM0 -> TPS61161 combo for control backlight.
14 #include <linux/backlight.h>
32 #define MAX_USER_VALUE (MAX_VALUE - MIN_VALUE)
41 	int brightness = bl->props.brightness;  in pandora_backlight_update_status()
45 	if (bl->props.power != BACKLIGHT_POWER_ON)  in pandora_backlight_update_status()
47 	if (bl->props.state & BL_CORE_FBBLANK)  in pandora_backlight_update_status()
49 	if (bl->props.state & BL_CORE_SUSPENDED)  in pandora_backlight_update_status()
56 		if (priv->old_state == PANDORABL_WAS_OFF)  in pandora_backlight_update_status()
69 	if (priv->old_state == PANDORABL_WAS_OFF) {  in pandora_backlight_update_status()
71 		 * set PWM duty cycle to max. TPS61161 seems to use this  in pandora_backlight_update_status()
72 		 * to calibrate it's PWM sensitivity when it starts.  in pandora_backlight_update_status()
86 		 * it often triggers unintentionally and disabes PWM control,  in pandora_backlight_update_status()
96 		priv->old_state = 0;  in pandora_backlight_update_status()
98 		priv->old_state = PANDORABL_WAS_OFF;  in pandora_backlight_update_status()
115 	priv = devm_kmalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);  in pandora_backlight_probe()
117 		return -ENOMEM;  in pandora_backlight_probe()
122 	bl = devm_backlight_device_register(&pdev->dev, pdev->name, &pdev->dev,  in pandora_backlight_probe()
125 		dev_err(&pdev->dev, "failed to register backlight\n");  in pandora_backlight_probe()
134 	priv->old_state = PANDORABL_WAS_OFF;  in pandora_backlight_probe()
135 	bl->props.brightness = MAX_USER_VALUE;  in pandora_backlight_probe()
138 	/* enable PWM function in pin mux */  in pandora_backlight_probe()
149 		.name	= "pandora-backlight",
157 MODULE_DESCRIPTION("Pandora Backlight Driver");
159 MODULE_ALIAS("platform:pandora-backlight");