iBoot/drivers/backlight/lp8559/lp8559.c

110 lines
2.8 KiB
C

/*
* Copyright (C) 2013 Apple Inc. All rights reserved.
*
* This document is the property of Apple Inc.
* It is considered confidential and proprietary.
*
* This document may not be reproduced or transmitted in any form,
* in whole or in part, without the express written permission of
* Apple Inc.
*/
#include <debug.h>
#include <drivers/iic.h>
#include <target/gpiodef.h>
#include <sys/task.h>
#include "lp8559.h"
static bool lp8559_probed;
static bool lp8559_present;
int beacon_reg_read(uint8_t reg_offset, uint8_t *value)
{
int status;
status = iic_read(BACKLIGHT_IIC_BUS, lp8559_IIC_ADDRESS, &reg_offset, 1, value, 1, IIC_NORMAL);
return status;
}
int beacon_reg_write(uint8_t reg_offset, uint8_t value)
{
int status;
uint8_t data[2] = {reg_offset, value};
status = iic_write(BACKLIGHT_IIC_BUS, lp8559_IIC_ADDRESS, data, 2);
return status;
}
int lp8559_backlight_enable(uint32_t backlight_level)
{
uint8_t cmd, epromid;
if (!lp8559_probed) {
// Probe for the lp8559 by reading a register
if (beacon_reg_read(lp8559_COMMAND, &cmd) == 0) {
// Mark the lp8559 as present
lp8559_present = true;
}
// Mark the lp8559 as probed
lp8559_probed = true;
}
// Return an error if the lp8559 is not present
if (!lp8559_present) {
dprintf(DEBUG_INFO, "failed to detect lp8559, bailing\n");
return -1;
}
// Workaround for chips with EPROMID = 0x0
// <rdar://problem/13700089> J85: Need to update register values in Beacon
beacon_reg_read(lp8559_EPROMID, &epromid);
if (epromid == 0x10) {
// Unlock protected registers
beacon_reg_write(lp8559_LOCK, 0xCF);
// Set inductor current limit to 2.2A
beacon_reg_write(lp8559_CONFIG, 0x62);
// Set IMAX to 20mA:
beacon_reg_write(lp8559_CURRENT, 0x02);
// Set PWM cutover point to 1mA
beacon_reg_write(lp8559_HYBRIDLO, 0x33);
// Set SLOPE and VERT headroom control
beacon_reg_write(lp8559_VHR1, 0x26);
// Set PWM global offset
beacon_reg_write(lp8559_TRIM9, 0x08);
// Lock protected registers
beacon_reg_write(lp8559_LOCK, 0x00);
}
beacon_reg_read(lp8559_COMMAND, &cmd);
// <rdar://problem/20615779>
// Dark boot may hand off to the OS with backlight disabled, but the OS backlight driver depends on iBoot
// to configure the backlight even if it's left disabled.
// read modify write
// Bit 0 - on, Bit 3 - enable DWI
cmd |= 0x9;
if (backlight_level == 0) {
cmd &= ~(0x9);
}
// Configure the backlight for defaults expect no ramp
beacon_reg_write(lp8559_COMMAND, cmd);
// IS this Required ??
// <rdar://problem/11055346> Not seeing the battery trap icon
// Delay to ensure that the lp8559 settings are processed before issuing dwi transaction
task_sleep(600);
extern int dwi_send_backlight_command(uint32_t backlight_command, uint32_t backlight_level);
dwi_send_backlight_command(0xA, backlight_level);
return 0;
}