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/* SPDX-License-Identifier: GPL-2.0-or-later */
/* This file is part of the coreboot project. */
#include <console/console.h>
#include <device/device.h>
#include <device/pnp.h>
#include "fintek_internal.h"
#include "f81866d.h"
#define LDN_REG 0x07
#define PORT_SELECT_REGISTER 0x27
#define MULTI_FUNC_SEL3_REG 0x29
#define IRQ_SHARE_REGISTER 0xF0
#define FIFO_SEL_MODE 0xF6
/*
* f81866d_uart_init enables all necessary registers for UART 3/4
* Fintek needs to know if pins are used as GPIO or UART pins
* Share interrupt usage needs to be enabled
*/
void f81866d_uart_init(struct device *dev)
{
struct resource *res = find_resource(dev, PNP_IDX_IO0);
u8 tmp;
if (!res) {
printk(BIOS_WARNING, "%s: No UART resource found.\n", __func__);
return;
}
pnp_enter_conf_mode(dev);
// Set Port Select Register (Bit 0) = 0
// before accessing Multi Function Select 3 Register
tmp = pnp_read_config(dev, PORT_SELECT_REGISTER);
pnp_write_config(dev, PORT_SELECT_REGISTER, tmp & 0xFE);
// Set UART 3 function (Bit 4/5), otherwise pin 36-43 are GPIO
if (dev->path.pnp.device == F81866D_SP3) {
tmp = pnp_read_config(dev, MULTI_FUNC_SEL3_REG);
pnp_write_config(dev, MULTI_FUNC_SEL3_REG, tmp | 0x30);
}
// Set UART 4 function (Bit 6/7), otherwise pin 44-51 are GPIO
if (dev->path.pnp.device == F81866D_SP4) {
tmp = pnp_read_config(dev, MULTI_FUNC_SEL3_REG);
pnp_write_config(dev, MULTI_FUNC_SEL3_REG, tmp | 0xC0);
}
// Select UART X in LDN register
pnp_write_config(dev, LDN_REG, dev->path.pnp.device & 0xff);
// Set IRQ trigger mode from active low to high (Bit 3)
tmp = pnp_read_config(dev, FIFO_SEL_MODE);
pnp_write_config(dev, FIFO_SEL_MODE, tmp | 0x8);
// Enable share interrupt (Bit 0)
pnp_write_config(dev, IRQ_SHARE_REGISTER, 0x01);
pnp_exit_conf_mode(dev);
}
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