1/* SPDX-License-Identifier: GPL-2.0+ */
2/*
3 *  Driver for 8250/16550-type serial ports
4 *
5 *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
6 *
7 *  Copyright (C) 2001 Russell King.
8 */
9
10#include <linux/bits.h>
11#include <linux/serial_8250.h>
12#include <linux/serial_reg.h>
13#include <linux/dmaengine.h>
14
15#include "../serial_mctrl_gpio.h"
16
17struct uart_8250_dma {
18	int (*tx_dma)(struct uart_8250_port *p);
19	int (*rx_dma)(struct uart_8250_port *p);
20	void (*prepare_tx_dma)(struct uart_8250_port *p);
21	void (*prepare_rx_dma)(struct uart_8250_port *p);
22
23	/* Filter function */
24	dma_filter_fn		fn;
25	/* Parameter to the filter function */
26	void			*rx_param;
27	void			*tx_param;
28
29	struct dma_slave_config	rxconf;
30	struct dma_slave_config	txconf;
31
32	struct dma_chan		*rxchan;
33	struct dma_chan		*txchan;
34
35	/* Device address base for DMA operations */
36	phys_addr_t		rx_dma_addr;
37	phys_addr_t		tx_dma_addr;
38
39	/* DMA address of the buffer in memory */
40	dma_addr_t		rx_addr;
41	dma_addr_t		tx_addr;
42
43	dma_cookie_t		rx_cookie;
44	dma_cookie_t		tx_cookie;
45
46	void			*rx_buf;
47
48	size_t			rx_size;
49	size_t			tx_size;
50
51	unsigned char		tx_running;
52	unsigned char		tx_err;
53	unsigned char		rx_running;
54};
55
56struct old_serial_port {
57	unsigned int uart;
58	unsigned int baud_base;
59	unsigned int port;
60	unsigned int irq;
61	upf_t        flags;
62	unsigned char io_type;
63	unsigned char __iomem *iomem_base;
64	unsigned short iomem_reg_shift;
65};
66
67struct serial8250_config {
68	const char	*name;
69	unsigned short	fifo_size;
70	unsigned short	tx_loadsz;
71	unsigned char	fcr;
72	unsigned char	rxtrig_bytes[UART_FCR_R_TRIG_MAX_STATE];
73	unsigned int	flags;
74};
75
76#define UART_CAP_FIFO	BIT(8)	/* UART has FIFO */
77#define UART_CAP_EFR	BIT(9)	/* UART has EFR */
78#define UART_CAP_SLEEP	BIT(10)	/* UART has IER sleep */
79#define UART_CAP_AFE	BIT(11)	/* MCR-based hw flow control */
80#define UART_CAP_UUE	BIT(12)	/* UART needs IER bit 6 set (Xscale) */
81#define UART_CAP_RTOIE	BIT(13)	/* UART needs IER bit 4 set (Xscale, Tegra) */
82#define UART_CAP_HFIFO	BIT(14)	/* UART has a "hidden" FIFO */
83#define UART_CAP_RPM	BIT(15)	/* Runtime PM is active while idle */
84#define UART_CAP_IRDA	BIT(16)	/* UART supports IrDA line discipline */
85#define UART_CAP_MINI	BIT(17)	/* Mini UART on BCM283X family lacks:
86					 * STOP PARITY EPAR SPAR WLEN5 WLEN6
87					 */
88#define UART_CAP_NOTEMT	BIT(18)	/* UART without interrupt on TEMT available */
89
90#define UART_BUG_QUOT	BIT(0)	/* UART has buggy quot LSB */
91#define UART_BUG_TXEN	BIT(1)	/* UART has buggy TX IIR status */
92#define UART_BUG_NOMSR	BIT(2)	/* UART has buggy MSR status bits (Au1x00) */
93#define UART_BUG_THRE	BIT(3)	/* UART has buggy THRE reassertion */
94#define UART_BUG_TXRACE	BIT(5)	/* UART Tx fails to set remote DR */
95
96
97#ifdef CONFIG_SERIAL_8250_SHARE_IRQ
98#define SERIAL8250_SHARE_IRQS 1
99#else
100#define SERIAL8250_SHARE_IRQS 0
101#endif
102
103#define SERIAL8250_PORT_FLAGS(_base, _irq, _flags)		\
104	{							\
105		.iobase		= _base,			\
106		.irq		= _irq,				\
107		.uartclk	= 1843200,			\
108		.iotype		= UPIO_PORT,			\
109		.flags		= UPF_BOOT_AUTOCONF | (_flags),	\
110	}
111
112#define SERIAL8250_PORT(_base, _irq) SERIAL8250_PORT_FLAGS(_base, _irq, 0)
113
114
115static inline int serial_in(struct uart_8250_port *up, int offset)
116{
117	return up->port.serial_in(&up->port, offset);
118}
119
120static inline void serial_out(struct uart_8250_port *up, int offset, int value)
121{
122	up->port.serial_out(&up->port, offset, value);
123}
124
125/**
126 *	serial_lsr_in - Read LSR register and preserve flags across reads
127 *	@up:	uart 8250 port
128 *
129 *	Read LSR register and handle saving non-preserved flags across reads.
130 *	The flags that are not preserved across reads are stored into
131 *	up->lsr_saved_flags.
132 *
133 *	Returns LSR value or'ed with the preserved flags (if any).
134 */
135static inline u16 serial_lsr_in(struct uart_8250_port *up)
136{
137	u16 lsr = up->lsr_saved_flags;
138
139	lsr |= serial_in(up, UART_LSR);
140	up->lsr_saved_flags = lsr & up->lsr_save_mask;
141
142	return lsr;
143}
144
145/*
146 * For the 16C950
147 */
148static void serial_icr_write(struct uart_8250_port *up, int offset, int value)
149{
150	serial_out(up, UART_SCR, offset);
151	serial_out(up, UART_ICR, value);
152}
153
154static unsigned int __maybe_unused serial_icr_read(struct uart_8250_port *up,
155						   int offset)
156{
157	unsigned int value;
158
159	serial_icr_write(up, UART_ACR, up->acr | UART_ACR_ICRRD);
160	serial_out(up, UART_SCR, offset);
161	value = serial_in(up, UART_ICR);
162	serial_icr_write(up, UART_ACR, up->acr);
163
164	return value;
165}
166
167void serial8250_clear_and_reinit_fifos(struct uart_8250_port *p);
168
169static inline u32 serial_dl_read(struct uart_8250_port *up)
170{
171	return up->dl_read(up);
172}
173
174static inline void serial_dl_write(struct uart_8250_port *up, u32 value)
175{
176	up->dl_write(up, value);
177}
178
179static inline bool serial8250_set_THRI(struct uart_8250_port *up)
180{
181	/* Port locked to synchronize UART_IER access against the console. */
182	lockdep_assert_held_once(&up->port.lock);
183
184	if (up->ier & UART_IER_THRI)
185		return false;
186	up->ier |= UART_IER_THRI;
187	serial_out(up, UART_IER, up->ier);
188	return true;
189}
190
191static inline bool serial8250_clear_THRI(struct uart_8250_port *up)
192{
193	/* Port locked to synchronize UART_IER access against the console. */
194	lockdep_assert_held_once(&up->port.lock);
195
196	if (!(up->ier & UART_IER_THRI))
197		return false;
198	up->ier &= ~UART_IER_THRI;
199	serial_out(up, UART_IER, up->ier);
200	return true;
201}
202
203struct uart_8250_port *serial8250_get_port(int line);
204
205void serial8250_rpm_get(struct uart_8250_port *p);
206void serial8250_rpm_put(struct uart_8250_port *p);
207
208void serial8250_rpm_get_tx(struct uart_8250_port *p);
209void serial8250_rpm_put_tx(struct uart_8250_port *p);
210
211int serial8250_em485_config(struct uart_port *port, struct ktermios *termios,
212			    struct serial_rs485 *rs485);
213void serial8250_em485_start_tx(struct uart_8250_port *p);
214void serial8250_em485_stop_tx(struct uart_8250_port *p);
215void serial8250_em485_destroy(struct uart_8250_port *p);
216extern struct serial_rs485 serial8250_em485_supported;
217
218/* MCR <-> TIOCM conversion */
219static inline int serial8250_TIOCM_to_MCR(int tiocm)
220{
221	int mcr = 0;
222
223	if (tiocm & TIOCM_RTS)
224		mcr |= UART_MCR_RTS;
225	if (tiocm & TIOCM_DTR)
226		mcr |= UART_MCR_DTR;
227	if (tiocm & TIOCM_OUT1)
228		mcr |= UART_MCR_OUT1;
229	if (tiocm & TIOCM_OUT2)
230		mcr |= UART_MCR_OUT2;
231	if (tiocm & TIOCM_LOOP)
232		mcr |= UART_MCR_LOOP;
233
234	return mcr;
235}
236
237static inline int serial8250_MCR_to_TIOCM(int mcr)
238{
239	int tiocm = 0;
240
241	if (mcr & UART_MCR_RTS)
242		tiocm |= TIOCM_RTS;
243	if (mcr & UART_MCR_DTR)
244		tiocm |= TIOCM_DTR;
245	if (mcr & UART_MCR_OUT1)
246		tiocm |= TIOCM_OUT1;
247	if (mcr & UART_MCR_OUT2)
248		tiocm |= TIOCM_OUT2;
249	if (mcr & UART_MCR_LOOP)
250		tiocm |= TIOCM_LOOP;
251
252	return tiocm;
253}
254
255/* MSR <-> TIOCM conversion */
256static inline int serial8250_MSR_to_TIOCM(int msr)
257{
258	int tiocm = 0;
259
260	if (msr & UART_MSR_DCD)
261		tiocm |= TIOCM_CAR;
262	if (msr & UART_MSR_RI)
263		tiocm |= TIOCM_RNG;
264	if (msr & UART_MSR_DSR)
265		tiocm |= TIOCM_DSR;
266	if (msr & UART_MSR_CTS)
267		tiocm |= TIOCM_CTS;
268
269	return tiocm;
270}
271
272static inline void serial8250_out_MCR(struct uart_8250_port *up, int value)
273{
274	serial_out(up, UART_MCR, value);
275
276	if (up->gpios)
277		mctrl_gpio_set(up->gpios, serial8250_MCR_to_TIOCM(value));
278}
279
280static inline int serial8250_in_MCR(struct uart_8250_port *up)
281{
282	int mctrl;
283
284	mctrl = serial_in(up, UART_MCR);
285
286	if (up->gpios) {
287		unsigned int mctrl_gpio = 0;
288
289		mctrl_gpio = mctrl_gpio_get_outputs(up->gpios, &mctrl_gpio);
290		mctrl |= serial8250_TIOCM_to_MCR(mctrl_gpio);
291	}
292
293	return mctrl;
294}
295
296bool alpha_jensen(void);
297void alpha_jensen_set_mctrl(struct uart_port *port, unsigned int mctrl);
298
299#ifdef CONFIG_SERIAL_8250_PNP
300int serial8250_pnp_init(void);
301void serial8250_pnp_exit(void);
302#else
303static inline int serial8250_pnp_init(void) { return 0; }
304static inline void serial8250_pnp_exit(void) { }
305#endif
306
307#ifdef CONFIG_SERIAL_8250_FINTEK
308int fintek_8250_probe(struct uart_8250_port *uart);
309#else
310static inline int fintek_8250_probe(struct uart_8250_port *uart) { return 0; }
311#endif
312
313#ifdef CONFIG_ARCH_OMAP1
314#include <linux/soc/ti/omap1-soc.h>
315static inline int is_omap1_8250(struct uart_8250_port *pt)
316{
317	int res;
318
319	switch (pt->port.mapbase) {
320	case OMAP1_UART1_BASE:
321	case OMAP1_UART2_BASE:
322	case OMAP1_UART3_BASE:
323		res = 1;
324		break;
325	default:
326		res = 0;
327		break;
328	}
329
330	return res;
331}
332
333static inline int is_omap1510_8250(struct uart_8250_port *pt)
334{
335	if (!cpu_is_omap1510())
336		return 0;
337
338	return is_omap1_8250(pt);
339}
340#else
341static inline int is_omap1_8250(struct uart_8250_port *pt)
342{
343	return 0;
344}
345static inline int is_omap1510_8250(struct uart_8250_port *pt)
346{
347	return 0;
348}
349#endif
350
351#ifdef CONFIG_SERIAL_8250_DMA
352extern int serial8250_tx_dma(struct uart_8250_port *);
353extern int serial8250_rx_dma(struct uart_8250_port *);
354extern void serial8250_rx_dma_flush(struct uart_8250_port *);
355extern int serial8250_request_dma(struct uart_8250_port *);
356extern void serial8250_release_dma(struct uart_8250_port *);
357
358static inline void serial8250_do_prepare_tx_dma(struct uart_8250_port *p)
359{
360	struct uart_8250_dma *dma = p->dma;
361
362	if (dma->prepare_tx_dma)
363		dma->prepare_tx_dma(p);
364}
365
366static inline void serial8250_do_prepare_rx_dma(struct uart_8250_port *p)
367{
368	struct uart_8250_dma *dma = p->dma;
369
370	if (dma->prepare_rx_dma)
371		dma->prepare_rx_dma(p);
372}
373
374static inline bool serial8250_tx_dma_running(struct uart_8250_port *p)
375{
376	struct uart_8250_dma *dma = p->dma;
377
378	return dma && dma->tx_running;
379}
380#else
381static inline int serial8250_tx_dma(struct uart_8250_port *p)
382{
383	return -1;
384}
385static inline int serial8250_rx_dma(struct uart_8250_port *p)
386{
387	return -1;
388}
389static inline void serial8250_rx_dma_flush(struct uart_8250_port *p) { }
390static inline int serial8250_request_dma(struct uart_8250_port *p)
391{
392	return -1;
393}
394static inline void serial8250_release_dma(struct uart_8250_port *p) { }
395
396static inline bool serial8250_tx_dma_running(struct uart_8250_port *p)
397{
398	return false;
399}
400#endif
401
402static inline int ns16550a_goto_highspeed(struct uart_8250_port *up)
403{
404	unsigned char status;
405
406	status = serial_in(up, 0x04); /* EXCR2 */
407#define PRESL(x) ((x) & 0x30)
408	if (PRESL(status) == 0x10) {
409		/* already in high speed mode */
410		return 0;
411	} else {
412		status &= ~0xB0; /* Disable LOCK, mask out PRESL[01] */
413		status |= 0x10;  /* 1.625 divisor for baud_base --> 921600 */
414		serial_out(up, 0x04, status);
415	}
416	return 1;
417}
418
419static inline int serial_index(struct uart_port *port)
420{
421	return port->minor - 64;
422}
423