path: root/drivers/usb/serial/f81534.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * F81532/F81534 USB to Serial Ports Bridge
 *
 * F81532 => 2 Serial Ports
 * F81534 => 4 Serial Ports
 *
 * Copyright (C) 2016 Feature Integration Technology Inc., (Fintek)
 * Copyright (C) 2016 Tom Tsai (Tom_Tsai@fintek.com.tw)
 * Copyright (C) 2016 Peter Hong (Peter_Hong@fintek.com.tw)
 *
 * The F81532/F81534 had 1 control endpoint for setting, 1 endpoint bulk-out
 * for all serial port TX and 1 endpoint bulk-in for all serial port read in
 * (Read Data/MSR/LSR).
 *
 * Write URB is fixed with 512bytes, per serial port used 128Bytes.
 * It can be described by f81534_prepare_write_buffer()
 *
 * Read URB is 512Bytes max, per serial port used 128Bytes.
 * It can be described by f81534_process_read_urb() and maybe received with
 * 128x1,2,3,4 bytes.
 *
 */
#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/usb.h>
#include <linux/usb/serial.h>
#include <linux/serial_reg.h>
#include <linux/module.h>
#include <linux/uaccess.h>

/* Serial Port register Address */
#define F81534_UART_BASE_ADDRESS	0x1200
#define F81534_UART_OFFSET		0x10
#define F81534_DIVISOR_LSB_REG		(0x00 + F81534_UART_BASE_ADDRESS)
#define F81534_DIVISOR_MSB_REG		(0x01 + F81534_UART_BASE_ADDRESS)
#define F81534_INTERRUPT_ENABLE_REG	(0x01 + F81534_UART_BASE_ADDRESS)
#define F81534_FIFO_CONTROL_REG		(0x02 + F81534_UART_BASE_ADDRESS)
#define F81534_LINE_CONTROL_REG		(0x03 + F81534_UART_BASE_ADDRESS)
#define F81534_MODEM_CONTROL_REG	(0x04 + F81534_UART_BASE_ADDRESS)
#define F81534_LINE_STATUS_REG		(0x05 + F81534_UART_BASE_ADDRESS)
#define F81534_MODEM_STATUS_REG		(0x06 + F81534_UART_BASE_ADDRESS)
#define F81534_CLOCK_REG		(0x08 + F81534_UART_BASE_ADDRESS)
#define F81534_CONFIG1_REG		(0x09 + F81534_UART_BASE_ADDRESS)

#define F81534_DEF_CONF_ADDRESS_START	0x3000
#define F81534_DEF_CONF_SIZE		12

#define F81534_CUSTOM_ADDRESS_START	0x2f00
#define F81534_CUSTOM_DATA_SIZE		0x10
#define F81534_CUSTOM_NO_CUSTOM_DATA	0xff
#define F81534_CUSTOM_VALID_TOKEN	0xf0
#define F81534_CONF_OFFSET		1
#define F81534_CONF_INIT_GPIO_OFFSET	4
#define F81534_CONF_WORK_GPIO_OFFSET	8
#define F81534_CONF_GPIO_SHUTDOWN	7
#define F81534_CONF_GPIO_RS232		1

#define F81534_MAX_DATA_BLOCK		64
#define F81534_MAX_BUS_RETRY		20

/* Default URB timeout for USB operations */
#define F81534_USB_MAX_RETRY		10
#define F81534_USB_TIMEOUT		2000
#define F81534_SET_GET_REGISTER		0xA0

#define F81534_NUM_PORT			4
#define F81534_UNUSED_PORT		0xff
#define F81534_WRITE_BUFFER_SIZE	512

#define DRIVER_DESC			"Fintek F81532/F81534"
#define FINTEK_VENDOR_ID_1		0x1934
#define FINTEK_VENDOR_ID_2		0x2C42
#define FINTEK_DEVICE_ID		0x1202
#define F81534_MAX_TX_SIZE		124
#define F81534_MAX_RX_SIZE		124
#define F81534_RECEIVE_BLOCK_SIZE	128
#define F81534_MAX_RECEIVE_BLOCK_SIZE	512

#define F81534_TOKEN_RECEIVE		0x01
#define F81534_TOKEN_WRITE		0x02
#define F81534_TOKEN_TX_EMPTY		0x03
#define F81534_TOKEN_MSR_CHANGE		0x04

/*
 * We used interal SPI bus to access FLASH section. We must wait the SPI bus to
 * idle if we performed any command.
 *
 * SPI Bus status register: F81534_BUS_REG_STATUS
 *	Bit 0/1	: BUSY
 *	Bit 2	: IDLE
 */
#define F81534_BUS_BUSY			(BIT(0) | BIT(1))
#define F81534_BUS_IDLE			BIT(2)
#define F81534_BUS_READ_DATA		0x1004
#define F81534_BUS_REG_STATUS		0x1003
#define F81534_BUS_REG_START		0x1002
#define F81534_BUS_REG_END		0x1001

#define F81534_CMD_READ			0x03

#define F81534_DEFAULT_BAUD_RATE	9600

#define F81534_PORT_CONF_RS232		0
#define F81534_PORT_CONF_RS485		BIT(0)
#define F81534_PORT_CONF_RS485_INVERT	(BIT(0) | BIT(1))
#define F81534_PORT_CONF_MODE_MASK	GENMASK(1, 0)
#define F81534_PORT_CONF_DISABLE_PORT	BIT(3)
#define F81534_PORT_CONF_NOT_EXIST_PORT	BIT(7)
#define F81534_PORT_UNAVAILABLE		\
	(F81534_PORT_CONF_DISABLE_PORT | F81534_PORT_CONF_NOT_EXIST_PORT)


#define F81534_1X_RXTRIGGER		0xc3
#define F81534_8X_RXTRIGGER		0xcf

/*
 * F81532/534 Clock registers (offset +08h)
 *
 * Bit0:	UART Enable (always on)
 * Bit2-1:	Clock source selector
 *			00: 1.846MHz.
 *			01: 18.46MHz.
 *			10: 24MHz.
 *			11: 14.77MHz.
 * Bit4:	Auto direction(RTS) control (RTS pin Low when TX)
 * Bit5:	Invert direction(RTS) when Bit4 enabled (RTS pin high when TX)
 */

#define F81534_UART_EN			BIT(0)
#define F81534_CLK_1_846_MHZ		0
#define F81534_CLK_18_46_MHZ		BIT(1)
#define F81534_CLK_24_MHZ		BIT(2)
#define F81534_CLK_14_77_MHZ		(BIT(1) | BIT(2))
#define F81534_CLK_MASK			GENMASK(2, 1)
#define F81534_CLK_TX_DELAY_1BIT	BIT(3)
#define F81534_CLK_RS485_MODE		BIT(4)
#define F81534_CLK_RS485_INVERT		BIT(5)

static const struct usb_device_id f81534_id_table[] = {
	{ USB_DEVICE(FINTEK_VENDOR_ID_1, FINTEK_DEVICE_ID) },
	{ USB_DEVICE(FINTEK_VENDOR_ID_2, FINTEK_DEVICE_ID) },
	{}			/* Terminating entry */
};

#define F81534_TX_EMPTY_BIT		0

struct f81534_serial_private {
	u8 conf_data[F81534_DEF_CONF_SIZE];
	int tty_idx[F81534_NUM_PORT];
	u8 setting_idx;
	int opened_port;
	struct mutex urb_mutex;
};

struct f81534_port_private {
	struct mutex mcr_mutex;
	struct mutex lcr_mutex;
	struct work_struct lsr_work;
	struct usb_serial_port *port;
	unsigned long tx_empty;
	spinlock_t msr_lock;
	u32 baud_base;
	u8 shadow_mcr;
	u8 shadow_lcr;
	u8 shadow_msr;
	u8 shadow_clk;
	u8 phy_num;
};

struct f81534_pin_data {
	const u16 reg_addr;
	const u8 reg_mask;
};

struct f81534_port_out_pin {
	struct f81534_pin_data pin[3];
};

/* Pin output value for M2/M1/M0(SD) */
static const struct f81534_port_out_pin f81534_port_out_pins[] = {
	 { { { 0x2ae8, BIT(7) }, { 0x2a90, BIT(5) }, { 0x2a90, BIT(4) } } },
	 { { { 0x2ae8, BIT(6) }, { 0x2ae8, BIT(0) }, { 0x2ae8, BIT(3) } } },
	 { { { 0x2a90, BIT(0) }, { 0x2ae8, BIT(2) }, { 0x2a80, BIT(6) } } },
	 { { { 0x2a90, BIT(3) }, { 0x2a90, BIT(2) }, { 0x2a90, BIT(1) } } },
};

static u32 const baudrate_table[] = { 115200, 921600, 1152000, 1500000 };
static u8 const clock_table[] = { F81534_CLK_1_846_MHZ, F81534_CLK_14_77_MHZ,
				F81534_CLK_18_46_MHZ, F81534_CLK_24_MHZ };

static int f81534_logic_to_phy_port(struct usb_serial *serial,
					struct usb_serial_port *port)
{
	struct f81534_serial_private *serial_priv =
			usb_get_serial_data(port->serial);
	int count = 0;
	int i;

	for (i = 0; i < F81534_NUM_PORT; ++i) {