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_and_reinit_fifos(struct uart_8250_port *p);
179
180 void serial8250_rpm_get(struct uart_8250_port *p);
181 void serial8250_rpm_put(struct uart_8250_port *p);
182 DEFINE_GUARD(serial8250_rpm, struct uart_8250_port *,
183 serial8250_rpm_get(_T), serial8250_rpm_put(_T));
184
serial_dl_read(struct uart_8250_port * up)185 static inline u32 serial_dl_read(struct uart_8250_port *up)
186 {
187 return up->dl_read(up);
188 }
189
serial_dl_write(struct uart_8250_port * up,u32 value)190 static inline void serial_dl_write(struct uart_8250_port *up, u32 value)
191 {
192 up->dl_write(up, value);
193 }
194
serial8250_set_THRI(struct uart_8250_port * up)195 static inline bool serial8250_set_THRI(struct uart_8250_port *up)
196 {
197 /* Port locked to synchronize UART_IER access against the console. */
198 lockdep_assert_held_once(&up->port.lock);
199
200 if (up->ier & UART_IER_THRI)
201 return false;
202 up->ier |= UART_IER_THRI;
203 serial_out(up, UART_IER, up->ier);
204 return true;
205 }
206
serial8250_clear_THRI(struct uart_8250_port * up)207 static inline bool serial8250_clear_THRI(struct uart_8250_port *up)
208 {
209 /* Port locked to synchronize UART_IER access against the console. */
210 lockdep_assert_held_once(&up->port.lock);
211
212 if (!(up->ier & UART_IER_THRI))
213 return false;
214 up->ier &= ~UART_IER_THRI;
215 serial_out(up, UART_IER, up->ier);
216 return true;
217 }
218
219 struct uart_8250_port *serial8250_setup_port(int index);
220 struct uart_8250_port *serial8250_get_port(int line);
221
222 int serial8250_em485_config(struct uart_port *port, struct ktermios *termios,
223 struct serial_rs485 *rs485);
224 void serial8250_em485_start_tx(struct uart_8250_port *p, bool toggle_ier);
225 void serial8250_em485_stop_tx(struct uart_8250_port *p, bool toggle_ier);
226 void serial8250_em485_destroy(struct uart_8250_port *p);
227 extern struct serial_rs485 serial8250_em485_supported;
228
229 /* MCR <-> TIOCM conversion */
serial8250_TIOCM_to_MCR(int tiocm)230 static inline int serial8250_TIOCM_to_MCR(int tiocm)
231 {
232 int mcr = 0;
233
234 if (tiocm & TIOCM_RTS)
235 mcr |= UART_MCR_RTS;
236 if (tiocm & TIOCM_DTR)
237 mcr |= UART_MCR_DTR;
238 if (tiocm & TIOCM_OUT1)
239 mcr |= UART_MCR_OUT1;
240 if (tiocm & TIOCM_OUT2)
241 mcr |= UART_MCR_OUT2;
242 if (tiocm & TIOCM_LOOP)
243 mcr |= UART_MCR_LOOP;
244
245 return mcr;
246 }
247
serial8250_MCR_to_TIOCM(int mcr)248 static inline int serial8250_MCR_to_TIOCM(int mcr)
249 {
250 int tiocm = 0;
251
252 if (mcr & UART_MCR_RTS)
253 tiocm |= TIOCM_RTS;
254 if (mcr & UART_MCR_DTR)
255 tiocm |= TIOCM_DTR;
256 if (mcr & UART_MCR_OUT1)
257 tiocm |= TIOCM_OUT1;
258 if (mcr & UART_MCR_OUT2)
259 tiocm |= TIOCM_OUT2;
260 if (mcr & UART_MCR_LOOP)
261 tiocm |= TIOCM_LOOP;
262
263 return tiocm;
264 }
265
266 /* MSR <-> TIOCM conversion */
serial8250_MSR_to_TIOCM(int msr)267 static inline int serial8250_MSR_to_TIOCM(int msr)
268 {
269 int tiocm = 0;
270
271 if (msr & UART_MSR_DCD)
272 tiocm |= TIOCM_CAR;
273 if (msr & UART_MSR_RI)
274 tiocm |= TIOCM_RNG;
275 if (msr & UART_MSR_DSR)
276 tiocm |= TIOCM_DSR;
277 if (msr & UART_MSR_CTS)
278 tiocm |= TIOCM_CTS;
279
280 return tiocm;
281 }
282
serial8250_out_MCR(struct uart_8250_port * up,int value)283 static inline void serial8250_out_MCR(struct uart_8250_port *up, int value)
284 {
285 serial_out(up, UART_MCR, value);
286
287 if (up->gpios)
288 mctrl_gpio_set(up->gpios, serial8250_MCR_to_TIOCM(value));
289 }
290
serial8250_in_MCR(struct uart_8250_port * up)291 static inline int serial8250_in_MCR(struct uart_8250_port *up)
292 {
293 int mctrl;
294
295 mctrl = serial_in(up, UART_MCR);
296
297 if (up->gpios) {
298 unsigned int mctrl_gpio = 0;
299
300 mctrl_gpio = mctrl_gpio_get_outputs(up->gpios, &mctrl_gpio);
301 mctrl |= serial8250_TIOCM_to_MCR(mctrl_gpio);
302 }
303
304 return mctrl;
305 }
306
307 #ifdef CONFIG_SERIAL_8250_PNP
308 int serial8250_pnp_init(void);
309 void serial8250_pnp_exit(void);
310 #else
serial8250_pnp_init(void)311 static inline int serial8250_pnp_init(void) { return 0; }
serial8250_pnp_exit(void)312 static inline void serial8250_pnp_exit(void) { }
313 #endif
314
315 #ifdef CONFIG_SERIAL_8250_RSA
316 void univ8250_rsa_support(struct uart_ops *ops, const struct uart_ops *core_ops);
317 void rsa_enable(struct uart_8250_port *up);
318 void rsa_disable(struct uart_8250_port *up);
319 void rsa_autoconfig(struct uart_8250_port *up);
320 void rsa_reset(struct uart_8250_port *up);
321 #else
univ8250_rsa_support(struct uart_ops * ops,const struct uart_ops * core_ops)322 static inline void univ8250_rsa_support(struct uart_ops *ops, const struct uart_ops *core_ops) { }
rsa_enable(struct uart_8250_port * up)323 static inline void rsa_enable(struct uart_8250_port *up) {}
rsa_disable(struct uart_8250_port * up)324 static inline void rsa_disable(struct uart_8250_port *up) {}
rsa_autoconfig(struct uart_8250_port * up)325 static inline void rsa_autoconfig(struct uart_8250_port *up) {}
rsa_reset(struct uart_8250_port * up)326 static inline void rsa_reset(struct uart_8250_port *up) {}
327 #endif
328
329 #ifdef CONFIG_SERIAL_8250_FINTEK
330 int fintek_8250_probe(struct uart_8250_port *uart);
331 #else
fintek_8250_probe(struct uart_8250_port * uart)332 static inline int fintek_8250_probe(struct uart_8250_port *uart) { return 0; }
333 #endif
334
335 #ifdef CONFIG_ARCH_OMAP1
336 #include <linux/soc/ti/omap1-soc.h>
is_omap1_8250(struct uart_8250_port * pt)337 static inline int is_omap1_8250(struct uart_8250_port *pt)
338 {
339 int res;
340
341 switch (pt->port.mapbase) {
342 case OMAP1_UART1_BASE:
343 case OMAP1_UART2_BASE:
344 case OMAP1_UART3_BASE:
345 res = 1;
346 break;
347 default:
348 res = 0;
349 break;
350 }
351
352 return res;
353 }
354
is_omap1510_8250(struct uart_8250_port * pt)355 static inline int is_omap1510_8250(struct uart_8250_port *pt)
356 {
357 if (!cpu_is_omap1510())
358 return 0;
359
360 return is_omap1_8250(pt);
361 }
362 #else
is_omap1_8250(struct uart_8250_port * pt)363 static inline int is_omap1_8250(struct uart_8250_port *pt)
364 {
365 return 0;
366 }
is_omap1510_8250(struct uart_8250_port * pt)367 static inline int is_omap1510_8250(struct uart_8250_port *pt)
368 {
369 return 0;
370 }
371 #endif
372
373 #ifdef CONFIG_SERIAL_8250_DMA
374 extern int serial8250_tx_dma(struct uart_8250_port *);
375 extern void serial8250_tx_dma_flush(struct uart_8250_port *);
376 extern int serial8250_rx_dma(struct uart_8250_port *);
377 extern void serial8250_rx_dma_flush(struct uart_8250_port *);
378 extern int serial8250_request_dma(struct uart_8250_port *);
379 extern void serial8250_release_dma(struct uart_8250_port *);
380
serial8250_do_prepare_tx_dma(struct uart_8250_port * p)381 static inline void serial8250_do_prepare_tx_dma(struct uart_8250_port *p)
382 {
383 struct uart_8250_dma *dma = p->dma;
384
385 if (dma->prepare_tx_dma)
386 dma->prepare_tx_dma(p);
387 }
388
serial8250_do_prepare_rx_dma(struct uart_8250_port * p)389 static inline void serial8250_do_prepare_rx_dma(struct uart_8250_port *p)
390 {
391 struct uart_8250_dma *dma = p->dma;
392
393 if (dma->prepare_rx_dma)
394 dma->prepare_rx_dma(p);
395 }
396
serial8250_tx_dma_running(struct uart_8250_port * p)397 static inline bool serial8250_tx_dma_running(struct uart_8250_port *p)
398 {
399 struct uart_8250_dma *dma = p->dma;
400
401 return dma && dma->tx_running;
402 }
403 #else
serial8250_tx_dma(struct uart_8250_port * p)404 static inline int serial8250_tx_dma(struct uart_8250_port *p)
405 {
406 return -1;
407 }
serial8250_tx_dma_flush(struct uart_8250_port * p)408 static inline void serial8250_tx_dma_flush(struct uart_8250_port *p) { }
serial8250_rx_dma(struct uart_8250_port * p)409 static inline int serial8250_rx_dma(struct uart_8250_port *p)
410 {
411 return -1;
412 }
serial8250_rx_dma_flush(struct uart_8250_port * p)413 static inline void serial8250_rx_dma_flush(struct uart_8250_port *p) { }
serial8250_request_dma(struct uart_8250_port * p)414 static inline int serial8250_request_dma(struct uart_8250_port *p)
415 {
416 return -1;
417 }
serial8250_release_dma(struct uart_8250_port * p)418 static inline void serial8250_release_dma(struct uart_8250_port *p) { }
419
serial8250_tx_dma_running(struct uart_8250_port * p)420 static inline bool serial8250_tx_dma_running(struct uart_8250_port *p)
421 {
422 return false;
423 }
424 #endif
425
ns16550a_goto_highspeed(struct uart_8250_port * up)426 static inline int ns16550a_goto_highspeed(struct uart_8250_port *up)
427 {
428 unsigned char status;
429
430 status = serial_in(up, 0x04); /* EXCR2 */
431 #define PRESL(x) ((x) & 0x30)
432 if (PRESL(status) == 0x10) {
433 /* already in high speed mode */
434 return 0;
435 } else {
436 status &= ~0xB0; /* Disable LOCK, mask out PRESL[01] */
437 status |= 0x10; /* 1.625 divisor for baud_base --> 921600 */
438 serial_out(up, 0x04, status);
439 }
440 return 1;
441 }
442
serial_index(struct uart_port * port)443 static inline int serial_index(struct uart_port *port)
444 {
445 return port->minor - 64;
446 }
447