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 
15 struct 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  */
33 struct 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 	unsigned int	(*serial_in)(struct uart_port *, int);
50 	void		(*serial_out)(struct uart_port *, int, int);
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  */
69 enum {
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 
83 struct uart_8250_dma;
84 struct 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  */
94 struct 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 
100 struct 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  */
124 struct 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 *);
165 	void			(*rs485_stop_tx)(struct uart_8250_port *);
166 
167 	/* Serial port overrun backoff */
168 	struct delayed_work overrun_backoff;
169 	u32 overrun_backoff_time_ms;
170 };
171 
up_to_u8250p(struct uart_port * up)172 static 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 
177 int serial8250_register_8250_port(const struct uart_8250_port *);
178 void serial8250_unregister_port(int line);
179 void serial8250_suspend_port(int line);
180 void serial8250_resume_port(int line);
181 
182 int early_serial_setup(struct uart_port *port);
183 int early_serial8250_setup(struct earlycon_device *device, const char *options);
184 
185 void serial8250_update_uartclk(struct uart_port *port, unsigned int uartclk);
186 void serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios,
187 			       const struct ktermios *old);
188 void serial8250_do_set_ldisc(struct uart_port *port, struct ktermios *termios);
189 unsigned int serial8250_do_get_mctrl(struct uart_port *port);
190 int serial8250_do_startup(struct uart_port *port);
191 void serial8250_do_shutdown(struct uart_port *port);
192 void serial8250_do_pm(struct uart_port *port, unsigned int state,
193 		      unsigned int oldstate);
194 void serial8250_do_set_mctrl(struct uart_port *port, unsigned int mctrl);
195 void serial8250_do_set_divisor(struct uart_port *port, unsigned int baud,
196 			       unsigned int quot, unsigned int quot_frac);
197 int fsl8250_handle_irq(struct uart_port *port);
198 int serial8250_handle_irq(struct uart_port *port, unsigned int iir);
199 u16 serial8250_rx_chars(struct uart_8250_port *up, u16 lsr);
200 void serial8250_read_char(struct uart_8250_port *up, u16 lsr);
201 void serial8250_tx_chars(struct uart_8250_port *up);
202 unsigned int serial8250_modem_status(struct uart_8250_port *up);
203 void serial8250_init_port(struct uart_8250_port *up);
204 void serial8250_set_defaults(struct uart_8250_port *up);
205 void serial8250_console_write(struct uart_8250_port *up, const char *s,
206 			      unsigned int count);
207 int serial8250_console_setup(struct uart_port *port, char *options, bool probe);
208 int serial8250_console_exit(struct uart_port *port);
209 
210 void serial8250_set_isa_configurator(void (*v)(int port, struct uart_port *up,
211 					       u32 *capabilities));
212 
213 #ifdef CONFIG_SERIAL_8250_RT288X
214 int rt288x_setup(struct uart_port *p);
215 int au_platform_setup(struct plat_serial8250_port *p);
216 #else
rt288x_setup(struct uart_port * p)217 static inline int rt288x_setup(struct uart_port *p) { return -ENODEV; }
au_platform_setup(struct plat_serial8250_port * p)218 static inline int au_platform_setup(struct plat_serial8250_port *p) { return -ENODEV; }
219 #endif
220 
221 #endif
222