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android_kernel_xiaomi_sm8350/drivers/tty/serial/8250/8250_fintek.c
Ilpo Järvinen 035bc3b734 serial: 8250_fintek: Check SER_RS485_RTS_* only with RS485 
[ Upstream commit af0179270977508df6986b51242825d7edd59caf ]

SER_RS485_RTS_ON_SEND and SER_RS485_RTS_AFTER_SEND relate to behavior
within RS485 operation. The driver checks if they have the same value
which is not possible to realize with the hardware. The check is taken
regardless of SER_RS485_ENABLED flag and -EINVAL is returned when the
check fails, which creates problems.

This check makes it unnecessarily complicated to turn RS485 mode off as
simple zeroed serial_rs485 struct will trigger that equal values check.
In addition, the driver itself memsets its rs485 structure to zero when
RS485 is disabled but if userspace would try to make an TIOCSRS485
ioctl() call with the very same struct, it would end up failing with
-EINVAL which doesn't make much sense.

Resolve the problem by moving the check inside SER_RS485_ENABLED block.

Fixes: 7ecc77011c ("serial: 8250_fintek: Return -EINVAL on invalid configuration")
Cc: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/035c738-8ea5-8b17-b1d7-84a7b3aeaa51@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-14 18:11:53 +02:00

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// SPDX-License-Identifier: GPL-2.0
/*
* Probe for F81216A LPC to 4 UART
*
* Copyright (C) 2014-2016 Ricardo Ribalda, Qtechnology A/S
*/
#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)
/*
* F81216H clock source register, the value and mask is the same with F81866,
* but it's on F0h.
*
* Clock speeds for UART (register F0h)
* 00: 1.8432MHz.
* 01: 18.432MHz.
* 10: 24MHz.
* 11: 14.769MHz.
*/
#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;
/* Force to deactive all SuperIO in this base_port */
outb(EXIT_KEY, base_port + ADDR_PORT);
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) {
/* Hardware do not support same RTS level on send and receive */
if (!(rs485->flags & SER_RS485_RTS_ON_SEND) ==
!(rs485->flags & SER_RS485_RTS_AFTER_SEND))
return -EINVAL;
memset(rs485->padding, 0, sizeof(rs485->padding));
config |= RS485_URA;
} else {
memset(rs485, 0, sizeof(*rs485));
}
rs485->flags &= SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND |
SER_RS485_RTS_AFTER_SEND;
/* Only the first port supports delays */
if (pdata->index) {
rs485->delay_rts_before_send = 0;
rs485->delay_rts_after_send = 0;
}
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)
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_set_termios(struct uart_port *port,
struct ktermios *termios,
struct ktermios *old)
{
struct fintek_8250 *pdata = port->private_data;
unsigned int baud = tty_termios_baud_rate(termios);
int i;
u8 reg;
static u32 baudrate_table[] = {115200, 921600, 1152000, 1500000};
static u8 clock_table[] = { F81866_UART_CLK_1_8432MHZ,
F81866_UART_CLK_14_769MHZ, F81866_UART_CLK_18_432MHZ,
F81866_UART_CLK_24MHZ };
/*
* We'll use serial8250_do_set_termios() for baud = 0, otherwise It'll
* crash on baudrate_table[i] % baud with "division by zero".
*/
if (!baud)
goto exit;
switch (pdata->pid) {
case CHIP_ID_F81216H:
reg = RS485;
break;
case CHIP_ID_F81866:
reg = F81866_UART_CLK;
break;
default:
/* Don't change clocksource with unknown PID */
dev_warn(port->dev,
"%s: pid: %x Not support. use default set_termios.\n",
__func__, pdata->pid);
goto exit;
}
for (i = 0; i < ARRAY_SIZE(baudrate_table); ++i) {
if (baud > baudrate_table[i] || baudrate_table[i] % baud != 0)
continue;
if (port->uartclk == baudrate_table[i] * 16)
break;
if (fintek_8250_enter_key(pdata->base_port, pdata->key))
continue;
port->uartclk = baudrate_table[i] * 16;
sio_write_reg(pdata, LDN, pdata->index);
sio_write_mask_reg(pdata, reg, F81866_UART_CLK_MASK,
clock_table[i]);
fintek_8250_exit_key(pdata->base_port);
break;
}
if (i == ARRAY_SIZE(baudrate_table)) {
baud = tty_termios_baud_rate(old);
tty_termios_encode_baud_rate(termios, baud, baud);
}
exit:
serial8250_do_set_termios(port, termios, old);
}
static void fintek_8250_set_termios_handler(struct uart_8250_port *uart)
{
struct fintek_8250 *pdata = uart->port.private_data;
switch (pdata->pid) {
case CHIP_ID_F81216H:
case CHIP_ID_F81866:
uart->port.set_termios = fintek_8250_set_termios;
break;
default:
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_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);
fintek_8250_set_termios_handler(uart);
return 0;
}
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