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/serial_8250.h>
11 #include <linux/serial_reg.h>
12 #include <linux/dmaengine.h>
13
14 #include "../serial_mctrl_gpio.h"
15
16 struct uart_8250_dma {
17 int (*tx_dma)(struct uart_8250_port *p);
18 int (*rx_dma)(struct uart_8250_port *p);
19
20 /* Filter function */
21 dma_filter_fn fn;
22 /* Parameter to the filter function */
23 void *rx_param;
24 void *tx_param;
25
26 struct dma_slave_config rxconf;
27 struct dma_slave_config txconf;
28
29 struct dma_chan *rxchan;
30 struct dma_chan *txchan;
31
32 /* Device address base for DMA operations */
33 phys_addr_t rx_dma_addr;
34 phys_addr_t tx_dma_addr;
35
36 /* DMA address of the buffer in memory */
37 dma_addr_t rx_addr;
38 dma_addr_t tx_addr;
39
40 dma_cookie_t rx_cookie;
41 dma_cookie_t tx_cookie;
42
43 void *rx_buf;
44
45 size_t rx_size;
46 size_t tx_size;
47
48 unsigned char tx_running;
49 unsigned char tx_err;
50 unsigned char rx_running;
51 };
52
53 struct old_serial_port {
54 unsigned int uart;
55 unsigned int baud_base;
56 unsigned int port;
57 unsigned int irq;
58 upf_t flags;
59 unsigned char io_type;
60 unsigned char __iomem *iomem_base;
61 unsigned short iomem_reg_shift;
62 };
63
64 struct serial8250_config {
65 const char *name;
66 unsigned short fifo_size;
67 unsigned short tx_loadsz;
68 unsigned char fcr;
69 unsigned char rxtrig_bytes[UART_FCR_R_TRIG_MAX_STATE];
70 unsigned int flags;
71 };
72
73 #define UART_CAP_FIFO (1 << 8) /* UART has FIFO */
74 #define UART_CAP_EFR (1 << 9) /* UART has EFR */
75 #define UART_CAP_SLEEP (1 << 10) /* UART has IER sleep */
76 #define UART_CAP_AFE (1 << 11) /* MCR-based hw flow control */
77 #define UART_CAP_UUE (1 << 12) /* UART needs IER bit 6 set (Xscale) */
78 #define UART_CAP_RTOIE (1 << 13) /* UART needs IER bit 4 set (Xscale, Tegra) */
79 #define UART_CAP_HFIFO (1 << 14) /* UART has a "hidden" FIFO */
80 #define UART_CAP_RPM (1 << 15) /* Runtime PM is active while idle */
81 #define UART_CAP_IRDA (1 << 16) /* UART supports IrDA line discipline */
82 #define UART_CAP_MINI (1 << 17) /* Mini UART on BCM283X family lacks:
83 * STOP PARITY EPAR SPAR WLEN5 WLEN6
84 */
85
86 #define UART_BUG_QUOT (1 << 0) /* UART has buggy quot LSB */
87 #define UART_BUG_TXEN (1 << 1) /* UART has buggy TX IIR status */
88 #define UART_BUG_NOMSR (1 << 2) /* UART has buggy MSR status bits (Au1x00) */
89 #define UART_BUG_THRE (1 << 3) /* UART has buggy THRE reassertion */
90 #define UART_BUG_PARITY (1 << 4) /* UART mishandles parity if FIFO enabled */
91 #define UART_BUG_TXRACE (1 << 5) /* UART Tx fails to set remote DR */
92
93
94 #ifdef CONFIG_SERIAL_8250_SHARE_IRQ
95 #define SERIAL8250_SHARE_IRQS 1
96 #else
97 #define SERIAL8250_SHARE_IRQS 0
98 #endif
99
100 #define SERIAL8250_PORT_FLAGS(_base, _irq, _flags) \
101 { \
102 .iobase = _base, \
103 .irq = _irq, \
104 .uartclk = 1843200, \
105 .iotype = UPIO_PORT, \
106 .flags = UPF_BOOT_AUTOCONF | (_flags), \
107 }
108
109 #define SERIAL8250_PORT(_base, _irq) SERIAL8250_PORT_FLAGS(_base, _irq, 0)
110
111
serial_in(struct uart_8250_port * up,int offset)112 static inline int serial_in(struct uart_8250_port *up, int offset)
113 {
114 return up->port.serial_in(&up->port, offset);
115 }
116
serial_out(struct uart_8250_port * up,int offset,int value)117 static inline void serial_out(struct uart_8250_port *up, int offset, int value)
118 {
119 up->port.serial_out(&up->port, offset, value);
120 }
121
122 /*
123 * For the 16C950
124 */
serial_icr_write(struct uart_8250_port * up,int offset,int value)125 static void serial_icr_write(struct uart_8250_port *up, int offset, int value)
126 {
127 serial_out(up, UART_SCR, offset);
128 serial_out(up, UART_ICR, value);
129 }
130
serial_icr_read(struct uart_8250_port * up,int offset)131 static unsigned int __maybe_unused serial_icr_read(struct uart_8250_port *up,
132 int offset)
133 {
134 unsigned int value;
135
136 serial_icr_write(up, UART_ACR, up->acr | UART_ACR_ICRRD);
137 serial_out(up, UART_SCR, offset);
138 value = serial_in(up, UART_ICR);
139 serial_icr_write(up, UART_ACR, up->acr);
140
141 return value;
142 }
143
144 void serial8250_clear_and_reinit_fifos(struct uart_8250_port *p);
145
serial_dl_read(struct uart_8250_port * up)146 static inline int serial_dl_read(struct uart_8250_port *up)
147 {
148 return up->dl_read(up);
149 }
150
serial_dl_write(struct uart_8250_port * up,int value)151 static inline void serial_dl_write(struct uart_8250_port *up, int value)
152 {
153 up->dl_write(up, value);
154 }
155
serial8250_set_THRI(struct uart_8250_port * up)156 static inline bool serial8250_set_THRI(struct uart_8250_port *up)
157 {
158 if (up->ier & UART_IER_THRI)
159 return false;
160 up->ier |= UART_IER_THRI;
161 serial_out(up, UART_IER, up->ier);
162 return true;
163 }
164
serial8250_clear_THRI(struct uart_8250_port * up)165 static inline bool serial8250_clear_THRI(struct uart_8250_port *up)
166 {
167 if (!(up->ier & UART_IER_THRI))
168 return false;
169 up->ier &= ~UART_IER_THRI;
170 serial_out(up, UART_IER, up->ier);
171 return true;
172 }
173
174 struct uart_8250_port *serial8250_get_port(int line);
175
176 void serial8250_rpm_get(struct uart_8250_port *p);
177 void serial8250_rpm_put(struct uart_8250_port *p);
178
179 void serial8250_rpm_get_tx(struct uart_8250_port *p);
180 void serial8250_rpm_put_tx(struct uart_8250_port *p);
181
182 int serial8250_em485_config(struct uart_port *port, struct serial_rs485 *rs485);
183 void serial8250_em485_start_tx(struct uart_8250_port *p);
184 void serial8250_em485_stop_tx(struct uart_8250_port *p);
185 void serial8250_em485_destroy(struct uart_8250_port *p);
186
187 /* MCR <-> TIOCM conversion */
serial8250_TIOCM_to_MCR(int tiocm)188 static inline int serial8250_TIOCM_to_MCR(int tiocm)
189 {
190 int mcr = 0;
191
192 if (tiocm & TIOCM_RTS)
193 mcr |= UART_MCR_RTS;
194 if (tiocm & TIOCM_DTR)
195 mcr |= UART_MCR_DTR;
196 if (tiocm & TIOCM_OUT1)
197 mcr |= UART_MCR_OUT1;
198 if (tiocm & TIOCM_OUT2)
199 mcr |= UART_MCR_OUT2;
200 if (tiocm & TIOCM_LOOP)
201 mcr |= UART_MCR_LOOP;
202
203 return mcr;
204 }
205
serial8250_MCR_to_TIOCM(int mcr)206 static inline int serial8250_MCR_to_TIOCM(int mcr)
207 {
208 int tiocm = 0;
209
210 if (mcr & UART_MCR_RTS)
211 tiocm |= TIOCM_RTS;
212 if (mcr & UART_MCR_DTR)
213 tiocm |= TIOCM_DTR;
214 if (mcr & UART_MCR_OUT1)
215 tiocm |= TIOCM_OUT1;
216 if (mcr & UART_MCR_OUT2)
217 tiocm |= TIOCM_OUT2;
218 if (mcr & UART_MCR_LOOP)
219 tiocm |= TIOCM_LOOP;
220
221 return tiocm;
222 }
223
224 /* MSR <-> TIOCM conversion */
serial8250_MSR_to_TIOCM(int msr)225 static inline int serial8250_MSR_to_TIOCM(int msr)
226 {
227 int tiocm = 0;
228
229 if (msr & UART_MSR_DCD)
230 tiocm |= TIOCM_CAR;
231 if (msr & UART_MSR_RI)
232 tiocm |= TIOCM_RNG;
233 if (msr & UART_MSR_DSR)
234 tiocm |= TIOCM_DSR;
235 if (msr & UART_MSR_CTS)
236 tiocm |= TIOCM_CTS;
237
238 return tiocm;
239 }
240
serial8250_out_MCR(struct uart_8250_port * up,int value)241 static inline void serial8250_out_MCR(struct uart_8250_port *up, int value)
242 {
243 serial_out(up, UART_MCR, value);
244
245 if (up->gpios)
246 mctrl_gpio_set(up->gpios, serial8250_MCR_to_TIOCM(value));
247 }
248
serial8250_in_MCR(struct uart_8250_port * up)249 static inline int serial8250_in_MCR(struct uart_8250_port *up)
250 {
251 int mctrl;
252
253 mctrl = serial_in(up, UART_MCR);
254
255 if (up->gpios) {
256 unsigned int mctrl_gpio = 0;
257
258 mctrl_gpio = mctrl_gpio_get_outputs(up->gpios, &mctrl_gpio);
259 mctrl |= serial8250_TIOCM_to_MCR(mctrl_gpio);
260 }
261
262 return mctrl;
263 }
264
265 #if defined(__alpha__) && !defined(CONFIG_PCI)
266 /*
267 * Digital did something really horribly wrong with the OUT1 and OUT2
268 * lines on at least some ALPHA's. The failure mode is that if either
269 * is cleared, the machine locks up with endless interrupts.
270 */
271 #define ALPHA_KLUDGE_MCR (UART_MCR_OUT2 | UART_MCR_OUT1)
272 #else
273 #define ALPHA_KLUDGE_MCR 0
274 #endif
275
276 #ifdef CONFIG_SERIAL_8250_PNP
277 int serial8250_pnp_init(void);
278 void serial8250_pnp_exit(void);
279 #else
serial8250_pnp_init(void)280 static inline int serial8250_pnp_init(void) { return 0; }
serial8250_pnp_exit(void)281 static inline void serial8250_pnp_exit(void) { }
282 #endif
283
284 #ifdef CONFIG_SERIAL_8250_FINTEK
285 int fintek_8250_probe(struct uart_8250_port *uart);
286 #else
fintek_8250_probe(struct uart_8250_port * uart)287 static inline int fintek_8250_probe(struct uart_8250_port *uart) { return 0; }
288 #endif
289
290 #ifdef CONFIG_ARCH_OMAP1
is_omap1_8250(struct uart_8250_port * pt)291 static inline int is_omap1_8250(struct uart_8250_port *pt)
292 {
293 int res;
294
295 switch (pt->port.mapbase) {
296 case OMAP1_UART1_BASE:
297 case OMAP1_UART2_BASE:
298 case OMAP1_UART3_BASE:
299 res = 1;
300 break;
301 default:
302 res = 0;
303 break;
304 }
305
306 return res;
307 }
308
is_omap1510_8250(struct uart_8250_port * pt)309 static inline int is_omap1510_8250(struct uart_8250_port *pt)
310 {
311 if (!cpu_is_omap1510())
312 return 0;
313
314 return is_omap1_8250(pt);
315 }
316 #else
is_omap1_8250(struct uart_8250_port * pt)317 static inline int is_omap1_8250(struct uart_8250_port *pt)
318 {
319 return 0;
320 }
is_omap1510_8250(struct uart_8250_port * pt)321 static inline int is_omap1510_8250(struct uart_8250_port *pt)
322 {
323 return 0;
324 }
325 #endif
326
327 #ifdef CONFIG_SERIAL_8250_DMA
328 extern int serial8250_tx_dma(struct uart_8250_port *);
329 extern int serial8250_rx_dma(struct uart_8250_port *);
330 extern void serial8250_rx_dma_flush(struct uart_8250_port *);
331 extern int serial8250_request_dma(struct uart_8250_port *);
332 extern void serial8250_release_dma(struct uart_8250_port *);
333
serial8250_tx_dma_running(struct uart_8250_port * p)334 static inline bool serial8250_tx_dma_running(struct uart_8250_port *p)
335 {
336 struct uart_8250_dma *dma = p->dma;
337
338 return dma && dma->tx_running;
339 }
340 #else
serial8250_tx_dma(struct uart_8250_port * p)341 static inline int serial8250_tx_dma(struct uart_8250_port *p)
342 {
343 return -1;
344 }
serial8250_rx_dma(struct uart_8250_port * p)345 static inline int serial8250_rx_dma(struct uart_8250_port *p)
346 {
347 return -1;
348 }
serial8250_rx_dma_flush(struct uart_8250_port * p)349 static inline void serial8250_rx_dma_flush(struct uart_8250_port *p) { }
serial8250_request_dma(struct uart_8250_port * p)350 static inline int serial8250_request_dma(struct uart_8250_port *p)
351 {
352 return -1;
353 }
serial8250_release_dma(struct uart_8250_port * p)354 static inline void serial8250_release_dma(struct uart_8250_port *p) { }
355
serial8250_tx_dma_running(struct uart_8250_port * p)356 static inline bool serial8250_tx_dma_running(struct uart_8250_port *p)
357 {
358 return false;
359 }
360 #endif
361
ns16550a_goto_highspeed(struct uart_8250_port * up)362 static inline int ns16550a_goto_highspeed(struct uart_8250_port *up)
363 {
364 unsigned char status;
365
366 status = serial_in(up, 0x04); /* EXCR2 */
367 #define PRESL(x) ((x) & 0x30)
368 if (PRESL(status) == 0x10) {
369 /* already in high speed mode */
370 return 0;
371 } else {
372 status &= ~0xB0; /* Disable LOCK, mask out PRESL[01] */
373 status |= 0x10; /* 1.625 divisor for baud_base --> 921600 */
374 serial_out(up, 0x04, status);
375 }
376 return 1;
377 }
378
serial_index(struct uart_port * port)379 static inline int serial_index(struct uart_port *port)
380 {
381 return port->minor - 64;
382 }
383