serial_8250.h

  1/* SPDX-License-Identifier: GPL-2.0-or-later */
  2/*
  3 *  linux/include/linux/serial_8250.h
  4 *
  5 *  Copyright (C) 2004 Russell King
  6 */
  7#ifndef _LINUX_SERIAL_8250_H
  8#define _LINUX_SERIAL_8250_H
  9
 10#include <linux/errno.h>
 11#include <linux/serial_core.h>
 12#include <linux/serial_reg.h>
 13#include <linux/platform_device.h>
 14
 15struct uart_8250_port;
 16
 17/*
 18 * This is the platform device platform_data structure
 19 *
 20 * @mapsize:	Port size for ioremap()
 21 * @bugs:	Port bugs
 22 *
 23 * @dl_read: ``u32 ()(struct uart_8250_port *up)``
 24 *
 25 *	UART divisor latch read.
 26 *
 27 * @dl_write: ``void ()(struct uart_8250_port *up, u32 value)``
 28 *
 29 *	Write @value into UART divisor latch.
 30 *
 31 *	Locking: Caller holds port's lock.
 32 */
 33struct plat_serial8250_port {
 34	unsigned long	iobase;		/* io base address */
 35	void __iomem	*membase;	/* ioremap cookie or NULL */
 36	resource_size_t	mapbase;	/* resource base */
 37	resource_size_t	mapsize;
 38	unsigned int	uartclk;	/* UART clock rate */
 39	unsigned int	irq;		/* interrupt number */
 40	unsigned long	irqflags;	/* request_irq flags */
 41	void            *private_data;
 42	unsigned char	regshift;	/* register shift */
 43	unsigned char	iotype;		/* UPIO_* */
 44	unsigned char	hub6;
 45	unsigned char	has_sysrq;	/* supports magic SysRq */
 46	unsigned int	type;		/* If UPF_FIXED_TYPE */
 47	upf_t		flags;		/* UPF_* flags */
 48	u16		bugs;		/* port bugs */
 49	u32		(*serial_in)(struct uart_port *, unsigned int offset);
 50	void		(*serial_out)(struct uart_port *, unsigned int offset, u32 val);
 51	u32		(*dl_read)(struct uart_8250_port *up);
 52	void		(*dl_write)(struct uart_8250_port *up, u32 value);
 53	void		(*set_termios)(struct uart_port *,
 54			               struct ktermios *new,
 55			               const struct ktermios *old);
 56	void		(*set_ldisc)(struct uart_port *,
 57				     struct ktermios *);
 58	unsigned int	(*get_mctrl)(struct uart_port *);
 59	int		(*handle_irq)(struct uart_port *);
 60	void		(*pm)(struct uart_port *, unsigned int state,
 61			      unsigned old);
 62	void		(*handle_break)(struct uart_port *);
 63};
 64
 65/*
 66 * Allocate 8250 platform device IDs.  Nothing is implied by
 67 * the numbering here, except for the legacy entry being -1.
 68 */
 69enum {
 70	PLAT8250_DEV_LEGACY = -1,
 71	PLAT8250_DEV_PLATFORM,
 72	PLAT8250_DEV_PLATFORM1,
 73	PLAT8250_DEV_PLATFORM2,
 74	PLAT8250_DEV_FOURPORT,
 75	PLAT8250_DEV_ACCENT,
 76	PLAT8250_DEV_BOCA,
 77	PLAT8250_DEV_EXAR_ST16C554,
 78	PLAT8250_DEV_HUB6,
 79	PLAT8250_DEV_AU1X00,
 80	PLAT8250_DEV_SM501,
 81};
 82
 83struct uart_8250_dma;
 84struct uart_8250_port;
 85
 86/**
 87 * 8250 core driver operations
 88 *
 89 * @setup_irq()		Setup irq handling. The universal 8250 driver links this
 90 *			port to the irq chain. Other drivers may @request_irq().
 91 * @release_irq()	Undo irq handling. The universal 8250 driver unlinks
 92 *			the port from the irq chain.
 93 */
 94struct uart_8250_ops {
 95	int		(*setup_irq)(struct uart_8250_port *);
 96	void		(*release_irq)(struct uart_8250_port *);
 97	void		(*setup_timer)(struct uart_8250_port *);
 98};
 99
100struct uart_8250_em485 {
101	struct hrtimer		start_tx_timer; /* "rs485 start tx" timer */
102	struct hrtimer		stop_tx_timer;  /* "rs485 stop tx" timer */
103	struct hrtimer		*active_timer;  /* pointer to active timer */
104	struct uart_8250_port	*port;          /* for hrtimer callbacks */
105	unsigned int		tx_stopped:1;	/* tx is currently stopped */
106};
107
108/*
109 * This should be used by drivers which want to register
110 * their own 8250 ports without registering their own
111 * platform device.  Using these will make your driver
112 * dependent on the 8250 driver.
113 *
114 * @dl_read: ``u32 ()(struct uart_8250_port *port)``
115 *
116 *	UART divisor latch read.
117 *
118 * @dl_write: ``void ()(struct uart_8250_port *port, u32 value)``
119 *
120 *	Write @value into UART divisor latch.
121 *
122 *	Locking: Caller holds port's lock.
123 */
124struct uart_8250_port {
125	struct uart_port	port;
126	struct timer_list	timer;		/* "no irq" timer */
127	struct list_head	list;		/* ports on this IRQ */
128	u32			capabilities;	/* port capabilities */
129	u16			bugs;		/* port bugs */
130	unsigned int		tx_loadsz;	/* transmit fifo load size */
131	unsigned char		acr;
132	unsigned char		fcr;
133	unsigned char		ier;
134	unsigned char		lcr;
135	unsigned char		mcr;
136	unsigned char		cur_iotype;	/* Running I/O type */
137	unsigned int		rpm_tx_active;
138	unsigned char		canary;		/* non-zero during system sleep
139						 *   if no_console_suspend
140						 */
141	unsigned char		probe;
142	struct mctrl_gpios	*gpios;
143#define UART_PROBE_RSA	(1 << 0)
144
145	/*
146	 * Some bits in registers are cleared on a read, so they must
147	 * be saved whenever the register is read but the bits will not
148	 * be immediately processed.
149	 */
150#define LSR_SAVE_FLAGS UART_LSR_BRK_ERROR_BITS
151	u16			lsr_saved_flags;
152	u16			lsr_save_mask;
153#define MSR_SAVE_FLAGS UART_MSR_ANY_DELTA
154	unsigned char		msr_saved_flags;
155
156	struct uart_8250_dma	*dma;
157	const struct uart_8250_ops *ops;
158
159	/* 8250 specific callbacks */
160	u32			(*dl_read)(struct uart_8250_port *up);
161	void			(*dl_write)(struct uart_8250_port *up, u32 value);
162
163	struct uart_8250_em485 *em485;
164	void			(*rs485_start_tx)(struct uart_8250_port *up, bool toggle_ier);
165	void			(*rs485_stop_tx)(struct uart_8250_port *up, bool toggle_ier);
166
167	/* Serial port overrun backoff */
168	struct delayed_work overrun_backoff;
169	u32 overrun_backoff_time_ms;
170};
171
172static inline struct uart_8250_port *up_to_u8250p(struct uart_port *up)
173{
174	return container_of(up, struct uart_8250_port, port);
175}
176
177int serial8250_register_8250_port(const struct uart_8250_port *);
178void serial8250_unregister_port(int line);
179void serial8250_suspend_port(int line);
180void serial8250_resume_port(int line);
181
182int early_serial_setup(struct uart_port *port);
183int early_serial8250_setup(struct earlycon_device *device, const char *options);
184
185void serial8250_update_uartclk(struct uart_port *port, unsigned int uartclk);
186void serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios,
187			       const struct ktermios *old);
188void serial8250_do_set_ldisc(struct uart_port *port, struct ktermios *termios);
189unsigned int serial8250_do_get_mctrl(struct uart_port *port);
190int serial8250_do_startup(struct uart_port *port);
191void serial8250_do_shutdown(struct uart_port *port);
192void serial8250_do_pm(struct uart_port *port, unsigned int state,
193		      unsigned int oldstate);
194void serial8250_do_set_mctrl(struct uart_port *port, unsigned int mctrl);
195void serial8250_do_set_divisor(struct uart_port *port, unsigned int baud,
196			       unsigned int quot);
197int fsl8250_handle_irq(struct uart_port *port);
198void serial8250_handle_irq_locked(struct uart_port *port, unsigned int iir);
199int serial8250_handle_irq(struct uart_port *port, unsigned int iir);
200u16 serial8250_rx_chars(struct uart_8250_port *up, u16 lsr);
201void serial8250_read_char(struct uart_8250_port *up, u16 lsr);
202void serial8250_tx_chars(struct uart_8250_port *up);
203unsigned int serial8250_modem_status(struct uart_8250_port *up);
204void serial8250_init_port(struct uart_8250_port *up);
205void serial8250_set_defaults(struct uart_8250_port *up);
206void serial8250_console_write(struct uart_8250_port *up, const char *s,
207			      unsigned int count);
208int serial8250_console_setup(struct uart_port *port, char *options, bool probe);
209int serial8250_console_exit(struct uart_port *port);
210
211void serial8250_set_isa_configurator(void (*v)(int port, struct uart_port *up,
212					       u32 *capabilities));
213
214#ifdef CONFIG_SERIAL_8250_CONSOLE
215extern int hp300_setup_serial_console(void) __init;
216#else
217static inline int hp300_setup_serial_console(void) { return 0; }
218#endif
219
220#ifdef CONFIG_SERIAL_8250_RT288X
221int rt288x_setup(struct uart_port *p);
222int au_platform_setup(struct plat_serial8250_port *p);
223#else
224static inline int rt288x_setup(struct uart_port *p) { return -ENODEV; }
225static inline int au_platform_setup(struct plat_serial8250_port *p) { return -ENODEV; }
226#endif
227
228#endif