linux/drivers/tty/serial/8250/8250_fintek.c

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/*
* Probe for F81216A LPC to 4 UART
*
* Copyright (C) 2014-2016 Ricardo Ribalda, Qtechnology A/S
*
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License.
*/
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/pnp.h>
#include <linux/kernel.h>
#include <linux/serial_core.h>
#include <linux/irq.h>
#include "8250.h"
#define ADDR_PORT 0
#define DATA_PORT 1
#define EXIT_KEY 0xAA
#define CHIP_ID1 0x20
#define CHIP_ID2 0x21
#define CHIP_ID_0 0x1602
#define CHIP_ID_1 0x0501
#define VENDOR_ID1 0x23
#define VENDOR_ID1_VAL 0x19
#define VENDOR_ID2 0x24
#define VENDOR_ID2_VAL 0x34
#define IO_ADDR1 0x61
#define IO_ADDR2 0x60
#define LDN 0x7
#define FINTEK_IRQ_MODE 0x70
#define IRQ_SHARE BIT(4)
#define IRQ_MODE_MASK (BIT(6) | BIT(5))
#define IRQ_LEVEL_LOW 0
#define IRQ_EDGE_HIGH BIT(5)
#define RS485 0xF0
#define RTS_INVERT BIT(5)
#define RS485_URA BIT(4)
#define RXW4C_IRA BIT(3)
#define TXW4C_IRA BIT(2)
struct fintek_8250 {
u16 base_port;
u8 index;
u8 key;
};
static u8 sio_read_reg(struct fintek_8250 *pdata, u8 reg)
{
outb(reg, pdata->base_port + ADDR_PORT);
return inb(pdata->base_port + DATA_PORT);
}
static void sio_write_reg(struct fintek_8250 *pdata, u8 reg, u8 data)
{
outb(reg, pdata->base_port + ADDR_PORT);
outb(data, pdata->base_port + DATA_PORT);
}
static void sio_write_mask_reg(struct fintek_8250 *pdata, u8 reg, u8 mask,
u8 data)
{
u8 tmp;
tmp = (sio_read_reg(pdata, reg) & ~mask) | (mask & data);
sio_write_reg(pdata, reg, tmp);
}
static int fintek_8250_enter_key(u16 base_port, u8 key)
{
if (!request_muxed_region(base_port, 2, "8250_fintek"))
return -EBUSY;
outb(key, base_port + ADDR_PORT);
outb(key, base_port + ADDR_PORT);
return 0;
}
static void fintek_8250_exit_key(u16 base_port)
{
outb(EXIT_KEY, base_port + ADDR_PORT);
release_region(base_port + ADDR_PORT, 2);
}
static int fintek_8250_check_id(struct fintek_8250 *pdata)
{
u16 chip;
if (sio_read_reg(pdata, VENDOR_ID1) != VENDOR_ID1_VAL)
return -ENODEV;
if (sio_read_reg(pdata, VENDOR_ID2) != VENDOR_ID2_VAL)
return -ENODEV;
chip = sio_read_reg(pdata, CHIP_ID1);
chip |= sio_read_reg(pdata, CHIP_ID2) << 8;
if (chip != CHIP_ID_0 && chip != CHIP_ID_1)
return -ENODEV;
return 0;
}
static int fintek_8250_rs485_config(struct uart_port *port,
struct serial_rs485 *rs485)
{
uint8_t config = 0;
struct fintek_8250 *pdata = port->private_data;
if (!pdata)
return -EINVAL;
if (rs485->flags & SER_RS485_ENABLED)
memset(rs485->padding, 0, sizeof(rs485->padding));
else
memset(rs485, 0, sizeof(*rs485));
rs485->flags &= SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND |
SER_RS485_RTS_AFTER_SEND;
if (rs485->delay_rts_before_send) {
rs485->delay_rts_before_send = 1;
config |= TXW4C_IRA;
}
if (rs485->delay_rts_after_send) {
rs485->delay_rts_after_send = 1;
config |= RXW4C_IRA;
}
if ((!!(rs485->flags & SER_RS485_RTS_ON_SEND)) ==
(!!(rs485->flags & SER_RS485_RTS_AFTER_SEND)))
rs485->flags &= SER_RS485_ENABLED;
else
config |= RS485_URA;
if (rs485->flags & SER_RS485_RTS_ON_SEND)
config |= RTS_INVERT;
if (fintek_8250_enter_key(pdata->base_port, pdata->key))
return -EBUSY;
sio_write_reg(pdata, LDN, pdata->index);
sio_write_reg(pdata, RS485, config);
fintek_8250_exit_key(pdata->base_port);
port->rs485 = *rs485;
return 0;
}
static int find_base_port(struct fintek_8250 *pdata, u16 io_address)
{
static const u16 addr[] = {0x4e, 0x2e};
static const u8 keys[] = {0x77, 0xa0, 0x87, 0x67};
int i, j, k;
for (i = 0; i < ARRAY_SIZE(addr); i++) {
for (j = 0; j < ARRAY_SIZE(keys); j++) {
pdata->base_port = addr[i];
pdata->key = keys[j];
if (fintek_8250_enter_key(addr[i], keys[j]))
continue;
if (fintek_8250_check_id(pdata)) {
fintek_8250_exit_key(addr[i]);
continue;
}
for (k = 0; k < 4; k++) {
u16 aux;
sio_write_reg(pdata, LDN, k);
aux = sio_read_reg(pdata, IO_ADDR1);
aux |= sio_read_reg(pdata, IO_ADDR2) << 8;
if (aux != io_address)
continue;
fintek_8250_exit_key(addr[i]);
pdata->index = k;
return 0;
}
fintek_8250_exit_key(addr[i]);
}
}
return -ENODEV;
}
static int fintek_8250_set_irq_mode(struct fintek_8250 *pdata, bool level_mode)
{
int status;
status = fintek_8250_enter_key(pdata->base_port, pdata->key);
if (status)
return status;
sio_write_reg(pdata, LDN, pdata->index);
sio_write_mask_reg(pdata, FINTEK_IRQ_MODE, IRQ_SHARE, IRQ_SHARE);
sio_write_mask_reg(pdata, FINTEK_IRQ_MODE, IRQ_MODE_MASK,
level_mode ? IRQ_LEVEL_LOW : IRQ_EDGE_HIGH);
fintek_8250_exit_key(pdata->base_port);
return 0;
}
int fintek_8250_probe(struct uart_8250_port *uart)
{
struct fintek_8250 *pdata;
struct fintek_8250 probe_data;
struct irq_data *irq_data = irq_get_irq_data(uart->port.irq);
bool level_mode = irqd_is_level_type(irq_data);
if (find_base_port(&probe_data, uart->port.iobase))
return -ENODEV;
pdata = devm_kzalloc(uart->port.dev, sizeof(*pdata), GFP_KERNEL);
if (!pdata)
return -ENOMEM;
memcpy(pdata, &probe_data, sizeof(probe_data));
uart->port.rs485_config = fintek_8250_rs485_config;
uart->port.private_data = pdata;
return fintek_8250_set_irq_mode(pdata, level_mode);
}