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remarkable-linux/drivers/tty/serial/8250/8250_fintek.c
Lukas Redlinger fab8a02b73 serial: 8250_fintek: Enable high speed mode on Fintek F81866 
Fintek F81866 supports baud rates higher than 115200 but needs to raise
it's clock speed from 1.84 to 14.76 MHz.
This is eight times faster, so gives 921600 as resulting baud_base.

F81866 clock register 0xf2:
    Bit 7-2    reserved
    Bit 1-0    00: 1.8432MHz
               01: 18.432MHz
               10: 24MHz
               11: 14.769MHz

Signed-off-by: Lukas Redlinger <rel+kernel@agilox.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-17 14:17:11 +09:00

379 lines
8.5 KiB
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_F81865 0x0407
#define CHIP_ID_F81866 0x1010
#define CHIP_ID_F81216AD 0x1602
#define CHIP_ID_F81216H 0x0501
#define CHIP_ID_F81216 0x0802
#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)
#define FIFO_CTRL 0xF6
#define FIFO_MODE_MASK (BIT(1) | BIT(0))
#define FIFO_MODE_128 (BIT(1) | BIT(0))
#define RXFTHR_MODE_MASK (BIT(5) | BIT(4))
#define RXFTHR_MODE_4X BIT(5)
#define F81216_LDN_LOW 0x0
#define F81216_LDN_HIGH 0x4
/*
* F81866 registers
*
* The IRQ setting mode of F81866 is not the same with F81216 series.
* Level/Low: IRQ_MODE0:0, IRQ_MODE1:0
* Edge/High: IRQ_MODE0:1, IRQ_MODE1:0
*
* Clock speeds for UART (register F2h)
* 00: 1.8432MHz.
* 01: 18.432MHz.
* 10: 24MHz.
* 11: 14.769MHz.
*/
#define F81866_IRQ_MODE 0xf0
#define F81866_IRQ_SHARE BIT(0)
#define F81866_IRQ_MODE0 BIT(1)
#define F81866_FIFO_CTRL FIFO_CTRL
#define F81866_IRQ_MODE1 BIT(3)
#define F81866_LDN_LOW 0x10
#define F81866_LDN_HIGH 0x16
#define F81866_UART_CLK 0xF2
#define F81866_UART_CLK_MASK (BIT(1) | BIT(0))
#define F81866_UART_CLK_1_8432MHZ 0
#define F81866_UART_CLK_14_769MHZ (BIT(1) | BIT(0))
#define F81866_UART_CLK_18_432MHZ BIT(0)
#define F81866_UART_CLK_24MHZ BIT(1)
struct fintek_8250 {
u16 pid;
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;
switch (chip) {
case CHIP_ID_F81865:
case CHIP_ID_F81866:
case CHIP_ID_F81216AD:
case CHIP_ID_F81216H:
case CHIP_ID_F81216:
break;
default:
return -ENODEV;
}
pdata->pid = chip;
return 0;
}
static int fintek_8250_get_ldn_range(struct fintek_8250 *pdata, int *min,
int *max)
{
switch (pdata->pid) {
case CHIP_ID_F81865:
case CHIP_ID_F81866:
*min = F81866_LDN_LOW;
*max = F81866_LDN_HIGH;
return 0;
case CHIP_ID_F81216AD:
case CHIP_ID_F81216H:
case CHIP_ID_F81216:
*min = F81216_LDN_LOW;
*max = F81216_LDN_HIGH;
return 0;
}
return -ENODEV;
}
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 void fintek_8250_set_irq_mode(struct fintek_8250 *pdata, bool is_level)
{
sio_write_reg(pdata, LDN, pdata->index);
switch (pdata->pid) {
case CHIP_ID_F81866:
sio_write_mask_reg(pdata, F81866_FIFO_CTRL, F81866_IRQ_MODE1,
0);
/* fall through */
case CHIP_ID_F81865:
sio_write_mask_reg(pdata, F81866_IRQ_MODE, F81866_IRQ_SHARE,
F81866_IRQ_SHARE);
sio_write_mask_reg(pdata, F81866_IRQ_MODE, F81866_IRQ_MODE0,
is_level ? 0 : F81866_IRQ_MODE0);
break;
case CHIP_ID_F81216AD:
case CHIP_ID_F81216H:
case CHIP_ID_F81216:
sio_write_mask_reg(pdata, FINTEK_IRQ_MODE, IRQ_SHARE,
IRQ_SHARE);
sio_write_mask_reg(pdata, FINTEK_IRQ_MODE, IRQ_MODE_MASK,
is_level ? IRQ_LEVEL_LOW : IRQ_EDGE_HIGH);
break;
}
}
static void fintek_8250_set_max_fifo(struct fintek_8250 *pdata)
{
switch (pdata->pid) {
case CHIP_ID_F81216H: /* 128Bytes FIFO */
case CHIP_ID_F81866:
sio_write_mask_reg(pdata, FIFO_CTRL,
FIFO_MODE_MASK | RXFTHR_MODE_MASK,
FIFO_MODE_128 | RXFTHR_MODE_4X);
break;
default: /* Default 16Bytes FIFO */
break;
}
}
static void fintek_8250_goto_highspeed(struct uart_8250_port *uart,
struct fintek_8250 *pdata)
{
sio_write_reg(pdata, LDN, pdata->index);
switch (pdata->pid) {
case CHIP_ID_F81866: /* set uart clock for high speed serial mode */
sio_write_mask_reg(pdata, F81866_UART_CLK,
F81866_UART_CLK_MASK,
F81866_UART_CLK_14_769MHZ);
uart->port.uartclk = 921600 * 16;
break;
default: /* leave clock speed untouched */
break;
}
}
static int probe_setup_port(struct fintek_8250 *pdata,
struct uart_8250_port *uart)
{
static const u16 addr[] = {0x4e, 0x2e};
static const u8 keys[] = {0x77, 0xa0, 0x87, 0x67};
struct irq_data *irq_data;
bool level_mode = false;
int i, j, k, min, max;
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_get_ldn_range(pdata, &min, &max)) {
fintek_8250_exit_key(addr[i]);
continue;
}
for (k = min; k < max; 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 != uart->port.iobase)
continue;
pdata->index = k;
irq_data = irq_get_irq_data(uart->port.irq);
if (irq_data)
level_mode =
irqd_is_level_type(irq_data);
fintek_8250_set_irq_mode(pdata, level_mode);
fintek_8250_set_max_fifo(pdata);
fintek_8250_goto_highspeed(uart, pdata);
fintek_8250_exit_key(addr[i]);
return 0;
}
fintek_8250_exit_key(addr[i]);
}
}
return -ENODEV;
}
static void fintek_8250_set_rs485_handler(struct uart_8250_port *uart)
{
struct fintek_8250 *pdata = uart->port.private_data;
switch (pdata->pid) {
case CHIP_ID_F81216AD:
case CHIP_ID_F81216H:
case CHIP_ID_F81866:
case CHIP_ID_F81865:
uart->port.rs485_config = fintek_8250_rs485_config;
break;
default: /* No RS485 Auto direction functional */
break;
}
}
int fintek_8250_probe(struct uart_8250_port *uart)
{
struct fintek_8250 *pdata;
struct fintek_8250 probe_data;
if (probe_setup_port(&probe_data, uart))
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.private_data = pdata;
fintek_8250_set_rs485_handler(uart);
return 0;
}
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