u-boot/board/atmel/common/board.c
Eugen Hristev afaea1f56c board: atmel: add support for pda detection
This adds the support for PDA detection as common code for
Atmel boards.
Using the one wire interface over GPIO , an EEPROM memory is read
and compared to preprogrammed values for PDA screens TM4300, TM7000
and TM7000B.
Once the PDA is detected, an environment variable is set accordingly.

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
2018-09-28 20:22:39 -04:00

68 lines
1.2 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2017 Microchip
* Wenyou Yang <wenyou.yang@microchip.com>
*/
#include <common.h>
#include <w1.h>
#include <w1-eeprom.h>
#include <dm/device-internal.h>
#define AT91_PDA_EEPROM_ID_OFFSET 15
#define AT91_PDA_EEPROM_ID_LENGTH 5
#define AT91_PDA_EEPROM_DEFAULT_BUS 0
void dummy(void)
{
}
#if defined CONFIG_W1
void at91_pda_detect(void)
{
struct udevice *bus, *dev;
u8 buf[AT91_PDA_EEPROM_ID_LENGTH + 1] = {0};
int ret;
int pda = 0;
ret = w1_get_bus(AT91_PDA_EEPROM_DEFAULT_BUS, &bus);
if (ret)
return;
for (device_find_first_child(bus, &dev);
dev;
device_find_next_child(&dev)) {
ret = device_probe(dev);
if (ret) {
continue;
} else {
ret = w1_eeprom_read_buf(dev, AT91_PDA_EEPROM_ID_OFFSET,
(u8 *)buf, AT91_PDA_EEPROM_ID_LENGTH);
if (ret)
return;
break;
}
}
pda = simple_strtoul((const char *)buf, NULL, 10);
switch (pda) {
case 7000:
if (buf[4] == 'B')
printf("PDA TM7000B detected\n");
else
printf("PDA TM7000 detected\n");
break;
case 4300:
printf("PDA TM4300 detected\n");
break;
case 5000:
printf("PDA TM5000 detected\n");
break;
}
env_set("pda", (const char *)buf);
}
#else
void at91_pda_detect(void)
{
}
#endif