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_core.h>
13 #include <linux/dmaengine.h>
14
15 #include "../serial_mctrl_gpio.h"
16
17 struct 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
56 struct 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
67 struct 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 /* Module parameters */
97 #define UART_NR CONFIG_SERIAL_8250_NR_UARTS
98
99 extern unsigned int nr_uarts;
100
101 #define SERIAL8250_PORT_FLAGS(_base, _irq, _flags) \
102 { \
103 .iobase = _base, \
104 .irq = _irq, \
105 .uartclk = 1843200, \
106 .iotype = UPIO_PORT, \
107 .flags = UPF_BOOT_AUTOCONF | (_flags), \
108 }
109
110 #define SERIAL8250_PORT(_base, _irq) SERIAL8250_PORT_FLAGS(_base, _irq, 0)
111
112 extern struct uart_driver serial8250_reg;
113 void serial8250_register_ports(struct uart_driver *drv, struct device *dev);
114
115 /* Legacy ISA bus related APIs */
116 typedef void (*serial8250_isa_config_fn)(int, struct uart_port *, u32 *);
117 extern serial8250_isa_config_fn serial8250_isa_config;
118
119 void serial8250_isa_init_ports(void);
120
121 extern struct platform_device *serial8250_isa_devs;
122
123 extern const struct uart_ops *univ8250_port_base_ops;
124 extern struct uart_ops univ8250_port_ops;
125
serial_in(struct uart_8250_port * up,int offset)126 static inline int serial_in(struct uart_8250_port *up, int offset)
127 {
128 return up->port.serial_in(&up->port, offset);
129 }
130
serial_out(struct uart_8250_port * up,int offset,int value)131 static inline void serial_out(struct uart_8250_port *up, int offset, int value)
132 {
133 up->port.serial_out(&up->port, offset, value);
134 }
135
136 /**
137 * serial_lsr_in - Read LSR register and preserve flags across reads
138 * @up: uart 8250 port
139 *
140 * Read LSR register and handle saving non-preserved flags across reads.
141 * The flags that are not preserved across reads are stored into
142 * up->lsr_saved_flags.
143 *
144 * Returns LSR value or'ed with the preserved flags (if any).
145 */
serial_lsr_in(struct uart_8250_port * up)146 static inline u16 serial_lsr_in(struct uart_8250_port *up)
147 {
148 u16 lsr = up->lsr_saved_flags;
149
150 lsr |= serial_in(up, UART_LSR);
151 up->lsr_saved_flags = lsr & up->lsr_save_mask;
152
153 return lsr;
154 }
155
156 /*
157 * For the 16C950
158 */
serial_icr_write(struct uart_8250_port * up,int offset,int value)159 static void serial_icr_write(struct uart_8250_port *up, int offset, int value)
160 {
161 serial_out(up, UART_SCR, offset);
162 serial_out(up, UART_ICR, value);
163 }
164
serial_icr_read(struct uart_8250_port * up,int offset)165 static unsigned int __maybe_unused serial_icr_read(struct uart_8250_port *up,
166 int offset)
167 {
168 unsigned int value;
169
170 serial_icr_write(up, UART_ACR, up->acr | UART_ACR_ICRRD);
171 serial_out(up, UART_SCR, offset);
172 value = serial_in(up, UART_ICR);
173 serial_icr_write(up, UART_ACR, up->acr);
174
175 return value;
176 }
177
178 void serial8250_clear_fifos(struct uart_8250_port *p);
179 void serial8250_clear_and_reinit_fifos(struct uart_8250_port *p);
180 void serial8250_fifo_wait_for_lsr_thre(struct uart_8250_port *up, unsigned int count);
181
182 void serial8250_rpm_get(struct uart_8250_port *p);
183 void serial8250_rpm_put(struct uart_8250_port *p);
184 DEFINE_GUARD(serial8250_rpm, struct uart_8250_port *,
185 serial8250_rpm_get(_T), serial8250_rpm_put(_T));
186
serial_dl_read(struct uart_8250_port * up)187 static inline u32 serial_dl_read(struct uart_8250_port *up)
188 {
189 return up->dl_read(up);
190 }
191
serial_dl_write(struct uart_8250_port * up,u32 value)192 static inline void serial_dl_write(struct uart_8250_port *up, u32 value)
193 {
194 up->dl_write(up, value);
195 }
196
serial8250_set_THRI(struct uart_8250_port * up)197 static inline bool serial8250_set_THRI(struct uart_8250_port *up)
198 {
199 /* Port locked to synchronize UART_IER access against the console. */
200 lockdep_assert_held_once(&up->port.lock);
201
202 if (up->ier & UART_IER_THRI)
203 return false;
204 up->ier |= UART_IER_THRI;
205 serial_out(up, UART_IER, up->ier);
206 return true;
207 }
208
serial8250_clear_THRI(struct uart_8250_port * up)209 static inline bool serial8250_clear_THRI(struct uart_8250_port *up)
210 {
211 /* Port locked to synchronize UART_IER access against the console. */
212 lockdep_assert_held_once(&up->port.lock);
213
214 if (!(up->ier & UART_IER_THRI))
215 return false;
216 up->ier &= ~UART_IER_THRI;
217 serial_out(up, UART_IER, up->ier);
218 return true;
219 }
220
221 struct uart_8250_port *serial8250_setup_port(int index);
222 struct uart_8250_port *serial8250_get_port(int line);
223
224 int serial8250_em485_config(struct uart_port *port, struct ktermios *termios,
225 struct serial_rs485 *rs485);
226 void serial8250_em485_start_tx(struct uart_8250_port *p, bool toggle_ier);
227 void serial8250_em485_stop_tx(struct uart_8250_port *p, bool toggle_ier);
228 void serial8250_em485_destroy(struct uart_8250_port *p);
229 extern struct serial_rs485 serial8250_em485_supported;
230
231 /* MCR <-> TIOCM conversion */
serial8250_TIOCM_to_MCR(int tiocm)232 static inline int serial8250_TIOCM_to_MCR(int tiocm)
233 {
234 int mcr = 0;
235
236 if (tiocm & TIOCM_RTS)
237 mcr |= UART_MCR_RTS;
238 if (tiocm & TIOCM_DTR)
239 mcr |= UART_MCR_DTR;
240 if (tiocm & TIOCM_OUT1)
241 mcr |= UART_MCR_OUT1;
242 if (tiocm & TIOCM_OUT2)
243 mcr |= UART_MCR_OUT2;
244 if (tiocm & TIOCM_LOOP)
245 mcr |= UART_MCR_LOOP;
246
247 return mcr;
248 }
249
serial8250_MCR_to_TIOCM(int mcr)250 static inline int serial8250_MCR_to_TIOCM(int mcr)
251 {
252 int tiocm = 0;
253
254 if (mcr & UART_MCR_RTS)
255 tiocm |= TIOCM_RTS;
256 if (mcr & UART_MCR_DTR)
257 tiocm |= TIOCM_DTR;
258 if (mcr & UART_MCR_OUT1)
259 tiocm |= TIOCM_OUT1;
260 if (mcr & UART_MCR_OUT2)
261 tiocm |= TIOCM_OUT2;
262 if (mcr & UART_MCR_LOOP)
263 tiocm |= TIOCM_LOOP;
264
265 return tiocm;
266 }
267
268 /* MSR <-> TIOCM conversion */
serial8250_MSR_to_TIOCM(int msr)269 static inline int serial8250_MSR_to_TIOCM(int msr)
270 {
271 int tiocm = 0;
272
273 if (msr & UART_MSR_DCD)
274 tiocm |= TIOCM_CAR;
275 if (msr & UART_MSR_RI)
276 tiocm |= TIOCM_RNG;
277 if (msr & UART_MSR_DSR)
278 tiocm |= TIOCM_DSR;
279 if (msr & UART_MSR_CTS)
280 tiocm |= TIOCM_CTS;
281
282 return tiocm;
283 }
284
serial8250_out_MCR(struct uart_8250_port * up,int value)285 static inline void serial8250_out_MCR(struct uart_8250_port *up, int value)
286 {
287 serial_out(up, UART_MCR, value);
288
289 if (up->gpios)
290 mctrl_gpio_set(up->gpios, serial8250_MCR_to_TIOCM(value));
291 }
292
serial8250_in_MCR(struct uart_8250_port * up)293 static inline int serial8250_in_MCR(struct uart_8250_port *up)
294 {
295 int mctrl;
296
297 mctrl = serial_in(up, UART_MCR);
298
299 if (up->gpios) {
300 unsigned int mctrl_gpio = 0;
301
302 mctrl_gpio = mctrl_gpio_get_outputs(up->gpios, &mctrl_gpio);
303 mctrl |= serial8250_TIOCM_to_MCR(mctrl_gpio);
304 }
305
306 return mctrl;
307 }
308
309 #ifdef CONFIG_SERIAL_8250_PNP
310 int serial8250_pnp_init(void);
311 void serial8250_pnp_exit(void);
312 #else
serial8250_pnp_init(void)313 static inline int serial8250_pnp_init(void) { return 0; }
serial8250_pnp_exit(void)314 static inline void serial8250_pnp_exit(void) { }
315 #endif
316
317 #ifdef CONFIG_SERIAL_8250_RSA
318 void univ8250_rsa_support(struct uart_ops *ops, const struct uart_ops *core_ops);
319 void rsa_enable(struct uart_8250_port *up);
320 void rsa_disable(struct uart_8250_port *up);
321 void rsa_autoconfig(struct uart_8250_port *up);
322 void rsa_reset(struct uart_8250_port *up);
323 #else
univ8250_rsa_support(struct uart_ops * ops,const struct uart_ops * core_ops)324 static inline void univ8250_rsa_support(struct uart_ops *ops, const struct uart_ops *core_ops) { }
rsa_enable(struct uart_8250_port * up)325 static inline void rsa_enable(struct uart_8250_port *up) {}
rsa_disable(struct uart_8250_port * up)326 static inline void rsa_disable(struct uart_8250_port *up) {}
rsa_autoconfig(struct uart_8250_port * up)327 static inline void rsa_autoconfig(struct uart_8250_port *up) {}
rsa_reset(struct uart_8250_port * up)328 static inline void rsa_reset(struct uart_8250_port *up) {}
329 #endif
330
331 #ifdef CONFIG_SERIAL_8250_FINTEK
332 int fintek_8250_probe(struct uart_8250_port *uart);
333 #else
fintek_8250_probe(struct uart_8250_port * uart)334 static inline int fintek_8250_probe(struct uart_8250_port *uart) { return 0; }
335 #endif
336
337 #ifdef CONFIG_ARCH_OMAP1
338 #include <linux/soc/ti/omap1-soc.h>
is_omap1_8250(struct uart_8250_port * pt)339 static inline int is_omap1_8250(struct uart_8250_port *pt)
340 {
341 int res;
342
343 switch (pt->port.mapbase) {
344 case OMAP1_UART1_BASE:
345 case OMAP1_UART2_BASE:
346 case OMAP1_UART3_BASE:
347 res = 1;
348 break;
349 default:
350 res = 0;
351 break;
352 }
353
354 return res;
355 }
356
is_omap1510_8250(struct uart_8250_port * pt)357 static inline int is_omap1510_8250(struct uart_8250_port *pt)
358 {
359 if (!cpu_is_omap1510())
360 return 0;
361
362 return is_omap1_8250(pt);
363 }
364 #else
is_omap1_8250(struct uart_8250_port * pt)365 static inline int is_omap1_8250(struct uart_8250_port *pt)
366 {
367 return 0;
368 }
is_omap1510_8250(struct uart_8250_port * pt)369 static inline int is_omap1510_8250(struct uart_8250_port *pt)
370 {
371 return 0;
372 }
373 #endif
374
375 #ifdef CONFIG_SERIAL_8250_DMA
376 extern int serial8250_tx_dma(struct uart_8250_port *);
377 extern void serial8250_tx_dma_flush(struct uart_8250_port *);
378 extern int serial8250_rx_dma(struct uart_8250_port *);
379 extern void serial8250_rx_dma_flush(struct uart_8250_port *);
380 extern int serial8250_request_dma(struct uart_8250_port *);
381 extern void serial8250_release_dma(struct uart_8250_port *);
382
serial8250_do_prepare_tx_dma(struct uart_8250_port * p)383 static inline void serial8250_do_prepare_tx_dma(struct uart_8250_port *p)
384 {
385 struct uart_8250_dma *dma = p->dma;
386
387 if (dma->prepare_tx_dma)
388 dma->prepare_tx_dma(p);
389 }
390
serial8250_do_prepare_rx_dma(struct uart_8250_port * p)391 static inline void serial8250_do_prepare_rx_dma(struct uart_8250_port *p)
392 {
393 struct uart_8250_dma *dma = p->dma;
394
395 if (dma->prepare_rx_dma)
396 dma->prepare_rx_dma(p);
397 }
398
serial8250_tx_dma_running(struct uart_8250_port * p)399 static inline bool serial8250_tx_dma_running(struct uart_8250_port *p)
400 {
401 struct uart_8250_dma *dma = p->dma;
402
403 return dma && dma->tx_running;
404 }
405
serial8250_tx_dma_pause(struct uart_8250_port * p)406 static inline void serial8250_tx_dma_pause(struct uart_8250_port *p)
407 {
408 struct uart_8250_dma *dma = p->dma;
409
410 if (!dma->tx_running)
411 return;
412
413 dmaengine_pause(dma->txchan);
414 }
415
serial8250_tx_dma_resume(struct uart_8250_port * p)416 static inline void serial8250_tx_dma_resume(struct uart_8250_port *p)
417 {
418 struct uart_8250_dma *dma = p->dma;
419
420 if (!dma->tx_running)
421 return;
422
423 dmaengine_resume(dma->txchan);
424 }
425 #else
serial8250_tx_dma(struct uart_8250_port * p)426 static inline int serial8250_tx_dma(struct uart_8250_port *p)
427 {
428 return -1;
429 }
serial8250_tx_dma_flush(struct uart_8250_port * p)430 static inline void serial8250_tx_dma_flush(struct uart_8250_port *p) { }
serial8250_rx_dma(struct uart_8250_port * p)431 static inline int serial8250_rx_dma(struct uart_8250_port *p)
432 {
433 return -1;
434 }
serial8250_rx_dma_flush(struct uart_8250_port * p)435 static inline void serial8250_rx_dma_flush(struct uart_8250_port *p) { }
serial8250_request_dma(struct uart_8250_port * p)436 static inline int serial8250_request_dma(struct uart_8250_port *p)
437 {
438 return -1;
439 }
serial8250_release_dma(struct uart_8250_port * p)440 static inline void serial8250_release_dma(struct uart_8250_port *p) { }
441
serial8250_tx_dma_running(struct uart_8250_port * p)442 static inline bool serial8250_tx_dma_running(struct uart_8250_port *p)
443 {
444 return false;
445 }
446
serial8250_tx_dma_pause(struct uart_8250_port * p)447 static inline void serial8250_tx_dma_pause(struct uart_8250_port *p) { }
serial8250_tx_dma_resume(struct uart_8250_port * p)448 static inline void serial8250_tx_dma_resume(struct uart_8250_port *p) { }
449 #endif
450
ns16550a_goto_highspeed(struct uart_8250_port * up)451 static inline int ns16550a_goto_highspeed(struct uart_8250_port *up)
452 {
453 unsigned char status;
454
455 status = serial_in(up, 0x04); /* EXCR2 */
456 #define PRESL(x) ((x) & 0x30)
457 if (PRESL(status) == 0x10) {
458 /* already in high speed mode */
459 return 0;
460 } else {
461 status &= ~0xB0; /* Disable LOCK, mask out PRESL[01] */
462 status |= 0x10; /* 1.625 divisor for baud_base --> 921600 */
463 serial_out(up, 0x04, status);
464 }
465 return 1;
466 }
467
serial_index(struct uart_port * port)468 static inline int serial_index(struct uart_port *port)
469 {
470 return port->minor - 64;
471 }
472