// SPDX-License-Identifier: GPL-2.0-only /* * leds-lp3944.c - driver for National Semiconductor LP3944 Funlight Chip * * Copyright (C) 2009 Antonio Ospite <[email protected]> */ /* * I2C driver for National Semiconductor LP3944 Funlight Chip * http://www.national.com/pf/LP/LP3944.html * * This helper chip can drive up to 8 leds, with two programmable DIM modes; * it could even be used as a gpio expander but this driver assumes it is used * as a led controller. * * The DIM modes are used to set _blink_ patterns for leds, the pattern is * specified supplying two parameters: * - period: from 0s to 1.6s * - duty cycle: percentage of the period the led is on, from 0 to 100 * * LP3944 can be found on Motorola A910 smartphone, where it drives the rgb * leds, the camera flash light and the displays backlights. */ #include <linux/module.h> #include <linux/i2c.h> #include <linux/slab.h> #include <linux/leds.h> #include <linux/mutex.h> #include <linux/leds-lp3944.h> /* Read Only Registers */ #define LP3944_REG_INPUT1 … #define LP3944_REG_REGISTER1 … #define LP3944_REG_PSC0 … #define LP3944_REG_PWM0 … #define LP3944_REG_PSC1 … #define LP3944_REG_PWM1 … #define LP3944_REG_LS0 … #define LP3944_REG_LS1 … /* These registers are not used to control leds in LP3944, they can store * arbitrary values which the chip will ignore. */ #define LP3944_REG_REGISTER8 … #define LP3944_REG_REGISTER9 … #define LP3944_DIM0 … #define LP3944_DIM1 … /* period in ms */ #define LP3944_PERIOD_MIN … #define LP3944_PERIOD_MAX … /* duty cycle is a percentage */ #define LP3944_DUTY_CYCLE_MIN … #define LP3944_DUTY_CYCLE_MAX … #define ldev_to_led(c) … /* Saved data */ struct lp3944_led_data { … }; struct lp3944_data { … }; static int lp3944_reg_read(struct i2c_client *client, u8 reg, u8 *value) { … } static int lp3944_reg_write(struct i2c_client *client, u8 reg, u8 value) { … } /** * lp3944_dim_set_period() - Set the period for DIM status * * @client: the i2c client * @dim: either LP3944_DIM0 or LP3944_DIM1 * @period: period of a blink, that is a on/off cycle, expressed in ms. */ static int lp3944_dim_set_period(struct i2c_client *client, u8 dim, u16 period) { … } /** * lp3944_dim_set_dutycycle - Set the duty cycle for DIM status * * @client: the i2c client * @dim: either LP3944_DIM0 or LP3944_DIM1 * @duty_cycle: percentage of a period during which a led is ON */ static int lp3944_dim_set_dutycycle(struct i2c_client *client, u8 dim, u8 duty_cycle) { … } /** * lp3944_led_set() - Set the led status * * @led: a lp3944_led_data structure * @status: one of LP3944_LED_STATUS_OFF * LP3944_LED_STATUS_ON * LP3944_LED_STATUS_DIM0 * LP3944_LED_STATUS_DIM1 */ static int lp3944_led_set(struct lp3944_led_data *led, u8 status) { … } static int lp3944_led_set_blink(struct led_classdev *led_cdev, unsigned long *delay_on, unsigned long *delay_off) { … } static int lp3944_led_set_brightness(struct led_classdev *led_cdev, enum led_brightness brightness) { … } static int lp3944_configure(struct i2c_client *client, struct lp3944_data *data, struct lp3944_platform_data *pdata) { … } static int lp3944_probe(struct i2c_client *client) { … } static void lp3944_remove(struct i2c_client *client) { … } /* lp3944 i2c driver struct */ static const struct i2c_device_id lp3944_id[] = …; MODULE_DEVICE_TABLE(i2c, lp3944_id); static struct i2c_driver lp3944_driver = …; module_i2c_driver(…) …; MODULE_AUTHOR(…) …; MODULE_DESCRIPTION(…) …; MODULE_LICENSE(…) …;
Codebase Browser
linux