iBoot/drivers/backlight/lm3534/lm3534.c

121 lines
3.5 KiB
C

/*
* Copyright (C) 2011-2015 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 <lib/mib.h>
#include <sys.h>
#include <target.h>
#define LM3534_GPR (0x10)
#define LM3534_DFS (0x11)
#define LM3534_RRR (0x12)
#define LM3534_BRL (0x13)
#define LM3534_BRH (0x14)
#define LM3534_AFT (0x32)
static bool lm3534_probed;
static uint32_t lm3534_address[2];
static uint32_t lm3534_bus[2];
static bool lm3534_present[2];
int lm3534_backlight_probe(void)
{
uint8_t data[1];
if (lm3534_probed)
return lm3534_present[0] ? 0 : -1;
lm3534_probed = true;
lm3534_bus[0] = mib_get_u32(kMIBTargetBacklight0I2CBus);
lm3534_bus[1] = mib_get_u32_opt(kMIBTargetBacklight1I2CBus, (uint32_t)-1);
lm3534_address[0] = mib_get_u32(kMIBTargetBacklight0I2CAddress);
lm3534_address[1] = mib_get_u32_opt(kMIBTargetBacklight1I2CAddress, (uint32_t)-1);
for (unsigned i = 0; i < 2; i++) {
if (lm3534_bus[i] == (uint32_t)-1) {
break;
}
dprintf(DEBUG_SPEW, "lm3534: probing backlight controller %u at i2c%u address 0x%x\n", i, lm3534_bus[i], lm3534_address[i]);
// Probe for the LM3534 by reading a register
data[0] = LM3534_GPR;
if (iic_read(lm3534_bus[i], lm3534_address[i], data, 1, data, 1, IIC_NORMAL) == 0) {
// Mark the LM3534 as present
lm3534_present[i] = true;
}
if (!lm3534_present[i]) {
if (i == 0) {
// Return an error if the first LM3534 is not present
dprintf(DEBUG_INFO, "lm3534: failed to detect backlight controller, bailing\n");
return -1;
} else {
// Depending on the display card attached, the second backlight
// controller may or may not exist. Its absense is not fatal.
dprintf(DEBUG_INFO, "lm3534: failed to detect second backlight controller, ignoring\n");
}
} else {
dprintf(DEBUG_SPEW, "lm3534: successfully probed backlight controller %u with value 0x%x\n", i, data[0]);
}
}
return 0;
}
int lm3534_backlight_enable(uint32_t backlight_level)
{
uint8_t data[2];
if (!lm3534_probed) {
lm3534_backlight_probe();
}
if (!lm3534_present[0])
return -1;
for (unsigned i = 0; i < 2; i++) {
if (!lm3534_present[i])
break;
// Configure the backlight for defaults expect no ramp
dprintf(DEBUG_SPEW, "lm3534: setting backlight controller %u to level %u\n", i, backlight_level);
data[0] = LM3534_GPR;
data[1] = target_lm3534_gpr(i);
// <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.
if (backlight_level == 0)
data[1] &= ~0x1; // bit 0: chip enable
iic_write(lm3534_bus[i], lm3534_address[i], data, 2);
uint32_t thresholdValue = 0;
if(mib_exists(kMIBTargetBacklightAutoFreqThresh, &thresholdValue)) {
dprintf(DEBUG_SPEW, "lm3534: Modify Auto-Frequency Threshold (0x%x)\n", thresholdValue);
data[0] = LM3534_AFT;
data[1] = thresholdValue;
iic_write(lm3534_bus[i], lm3534_address[i], data, 2);
}
}
// <rdar://problem/11055346> Not seeing the battery trap icon
// Delay to ensure that the LM3534 settings are processed before issuing dwi transaction
spin(600);
extern int dwi_send_backlight_command(uint32_t backlight_command, uint32_t backlight_level);
dwi_send_backlight_command(0xA, backlight_level);
return 0;
}