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
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_PARITY BIT(4) /* UART mishandles parity if FIFO enabled */
95 #define UART_BUG_TXRACE BIT(5) /* UART Tx fails to set remote DR */
96
97
98 #ifdef CONFIG_SERIAL_8250_SHARE_IRQ
99 #define SERIAL8250_SHARE_IRQS 1
100 #else
101 #define SERIAL8250_SHARE_IRQS 0
102 #endif
103
104 #define SERIAL8250_PORT_FLAGS(_base, _irq, _flags) \
105 { \
106 .iobase = _base, \
107 .irq = _irq, \
108 .uartclk = 1843200, \
109 .iotype = UPIO_PORT, \
110 .flags = UPF_BOOT_AUTOCONF | (_flags), \
111 }
112
113 #define SERIAL8250_PORT(_base, _irq) SERIAL8250_PORT_FLAGS(_base, _irq, 0)
114
115
serial_in(struct uart_8250_port * up,int offset)116 static inline int serial_in(struct uart_8250_port *up, int offset)
117 {
118 return up->port.serial_in(&up->port, offset);
119 }
120
serial_out(struct uart_8250_port * up,int offset,int value)121 static inline void serial_out(struct uart_8250_port *up, int offset, int value)
122 {
123 up->port.serial_out(&up->port, offset, value);
124 }
125
126 /**
127 * serial_lsr_in - Read LSR register and preserve flags across reads
128 * @up: uart 8250 port
129 *
130 * Read LSR register and handle saving non-preserved flags across reads.
131 * The flags that are not preserved across reads are stored into
132 * up->lsr_saved_flags.
133 *
134 * Returns LSR value or'ed with the preserved flags (if any).
135 */
serial_lsr_in(struct uart_8250_port * up)136 static inline u16 serial_lsr_in(struct uart_8250_port *up)
137 {
138 u16 lsr = up->lsr_saved_flags;
139
140 lsr |= serial_in(up, UART_LSR);
141 up->lsr_saved_flags = lsr & up->lsr_save_mask;
142
143 return lsr;
144 }
145
146 /*
147 * For the 16C950
148 */
serial_icr_write(struct uart_8250_port * up,int offset,int value)149 static void serial_icr_write(struct uart_8250_port *up, int offset, int value)
150 {
151 serial_out(up, UART_SCR, offset);
152 serial_out(up, UART_ICR, value);
153 }
154
serial_icr_read(struct uart_8250_port * up,int offset)155 static unsigned int __maybe_unused serial_icr_read(struct uart_8250_port *up,
156 int offset)
157 {
158 unsigned int value;
159
160 serial_icr_write(up, UART_ACR, up->acr | UART_ACR_ICRRD);
161 serial_out(up, UART_SCR, offset);
162 value = serial_in(up, UART_ICR);
163 serial_icr_write(up, UART_ACR, up->acr);
164
165 return value;
166 }
167
168 void serial8250_clear_and_reinit_fifos(struct uart_8250_port *p);
169
serial_dl_read(struct uart_8250_port * up)170 static inline int serial_dl_read(struct uart_8250_port *up)
171 {
172 return up->dl_read(up);
173 }
174
serial_dl_write(struct uart_8250_port * up,int value)175 static inline void serial_dl_write(struct uart_8250_port *up, int value)
176 {
177 up->dl_write(up, value);
178 }
179
serial8250_set_THRI(struct uart_8250_port * up)180 static inline bool serial8250_set_THRI(struct uart_8250_port *up)
181 {
182 if (up->ier & UART_IER_THRI)
183 return false;
184 up->ier |= UART_IER_THRI;
185 serial_out(up, UART_IER, up->ier);
186 return true;
187 }
188
serial8250_clear_THRI(struct uart_8250_port * up)189 static inline bool serial8250_clear_THRI(struct uart_8250_port *up)
190 {
191 if (!(up->ier & UART_IER_THRI))
192 return false;
193 up->ier &= ~UART_IER_THRI;
194 serial_out(up, UART_IER, up->ier);
195 return true;
196 }
197
198 struct uart_8250_port *serial8250_get_port(int line);
199
200 void serial8250_rpm_get(struct uart_8250_port *p);
201 void serial8250_rpm_put(struct uart_8250_port *p);
202
203 void serial8250_rpm_get_tx(struct uart_8250_port *p);
204 void serial8250_rpm_put_tx(struct uart_8250_port *p);
205
206 int serial8250_em485_config(struct uart_port *port, struct ktermios *termios,
207 struct serial_rs485 *rs485);
208 void serial8250_em485_start_tx(struct uart_8250_port *p);
209 void serial8250_em485_stop_tx(struct uart_8250_port *p);
210 void serial8250_em485_destroy(struct uart_8250_port *p);
211 extern struct serial_rs485 serial8250_em485_supported;
212
213 /* MCR <-> TIOCM conversion */
serial8250_TIOCM_to_MCR(int tiocm)214 static inline int serial8250_TIOCM_to_MCR(int tiocm)
215 {
216 int mcr = 0;
217
218 if (tiocm & TIOCM_RTS)
219 mcr |= UART_MCR_RTS;
220 if (tiocm & TIOCM_DTR)
221 mcr |= UART_MCR_DTR;
222 if (tiocm & TIOCM_OUT1)
223 mcr |= UART_MCR_OUT1;
224 if (tiocm & TIOCM_OUT2)
225 mcr |= UART_MCR_OUT2;
226 if (tiocm & TIOCM_LOOP)
227 mcr |= UART_MCR_LOOP;
228
229 return mcr;
230 }
231
serial8250_MCR_to_TIOCM(int mcr)232 static inline int serial8250_MCR_to_TIOCM(int mcr)
233 {
234 int tiocm = 0;
235
236 if (mcr & UART_MCR_RTS)
237 tiocm |= TIOCM_RTS;
238 if (mcr & UART_MCR_DTR)
239 tiocm |= TIOCM_DTR;
240 if (mcr & UART_MCR_OUT1)
241 tiocm |= TIOCM_OUT1;
242 if (mcr & UART_MCR_OUT2)
243 tiocm |= TIOCM_OUT2;
244 if (mcr & UART_MCR_LOOP)
245 tiocm |= TIOCM_LOOP;
246
247 return tiocm;
248 }
249
250 /* MSR <-> TIOCM conversion */
serial8250_MSR_to_TIOCM(int msr)251 static inline int serial8250_MSR_to_TIOCM(int msr)
252 {
253 int tiocm = 0;
254
255 if (msr & UART_MSR_DCD)
256 tiocm |= TIOCM_CAR;
257 if (msr & UART_MSR_RI)
258 tiocm |= TIOCM_RNG;
259 if (msr & UART_MSR_DSR)
260 tiocm |= TIOCM_DSR;
261 if (msr & UART_MSR_CTS)
262 tiocm |= TIOCM_CTS;
263
264 return tiocm;
265 }
266
serial8250_out_MCR(struct uart_8250_port * up,int value)267 static inline void serial8250_out_MCR(struct uart_8250_port *up, int value)
268 {
269 serial_out(up, UART_MCR, value);
270
271 if (up->gpios)
272 mctrl_gpio_set(up->gpios, serial8250_MCR_to_TIOCM(value));
273 }
274
serial8250_in_MCR(struct uart_8250_port * up)275 static inline int serial8250_in_MCR(struct uart_8250_port *up)
276 {
277 int mctrl;
278
279 mctrl = serial_in(up, UART_MCR);
280
281 if (up->gpios) {
282 unsigned int mctrl_gpio = 0;
283
284 mctrl_gpio = mctrl_gpio_get_outputs(up->gpios, &mctrl_gpio);
285 mctrl |= serial8250_TIOCM_to_MCR(mctrl_gpio);
286 }
287
288 return mctrl;
289 }
290
291 bool alpha_jensen(void);
292 void alpha_jensen_set_mctrl(struct uart_port *port, unsigned int mctrl);
293
294 #ifdef CONFIG_SERIAL_8250_PNP
295 int serial8250_pnp_init(void);
296 void serial8250_pnp_exit(void);
297 #else
serial8250_pnp_init(void)298 static inline int serial8250_pnp_init(void) { return 0; }
serial8250_pnp_exit(void)299 static inline void serial8250_pnp_exit(void) { }
300 #endif
301
302 #ifdef CONFIG_SERIAL_8250_FINTEK
303 int fintek_8250_probe(struct uart_8250_port *uart);
304 #else
fintek_8250_probe(struct uart_8250_port * uart)305 static inline int fintek_8250_probe(struct uart_8250_port *uart) { return 0; }
306 #endif
307
308 #ifdef CONFIG_ARCH_OMAP1
309 #include <linux/soc/ti/omap1-soc.h>
is_omap1_8250(struct uart_8250_port * pt)310 static inline int is_omap1_8250(struct uart_8250_port *pt)
311 {
312 int res;
313
314 switch (pt->port.mapbase) {
315 case OMAP1_UART1_BASE:
316 case OMAP1_UART2_BASE:
317 case OMAP1_UART3_BASE:
318 res = 1;
319 break;
320 default:
321 res = 0;
322 break;
323 }
324
325 return res;
326 }
327
is_omap1510_8250(struct uart_8250_port * pt)328 static inline int is_omap1510_8250(struct uart_8250_port *pt)
329 {
330 if (!cpu_is_omap1510())
331 return 0;
332
333 return is_omap1_8250(pt);
334 }
335 #else
is_omap1_8250(struct uart_8250_port * pt)336 static inline int is_omap1_8250(struct uart_8250_port *pt)
337 {
338 return 0;
339 }
is_omap1510_8250(struct uart_8250_port * pt)340 static inline int is_omap1510_8250(struct uart_8250_port *pt)
341 {
342 return 0;
343 }
344 #endif
345
346 #ifdef CONFIG_SERIAL_8250_DMA
347 extern int serial8250_tx_dma(struct uart_8250_port *);
348 extern int serial8250_rx_dma(struct uart_8250_port *);
349 extern void serial8250_rx_dma_flush(struct uart_8250_port *);
350 extern int serial8250_request_dma(struct uart_8250_port *);
351 extern void serial8250_release_dma(struct uart_8250_port *);
352
serial8250_do_prepare_tx_dma(struct uart_8250_port * p)353 static inline void serial8250_do_prepare_tx_dma(struct uart_8250_port *p)
354 {
355 struct uart_8250_dma *dma = p->dma;
356
357 if (dma->prepare_tx_dma)
358 dma->prepare_tx_dma(p);
359 }
360
serial8250_do_prepare_rx_dma(struct uart_8250_port * p)361 static inline void serial8250_do_prepare_rx_dma(struct uart_8250_port *p)
362 {
363 struct uart_8250_dma *dma = p->dma;
364
365 if (dma->prepare_rx_dma)
366 dma->prepare_rx_dma(p);
367 }
368 #else
serial8250_tx_dma(struct uart_8250_port * p)369 static inline int serial8250_tx_dma(struct uart_8250_port *p)
370 {
371 return -1;
372 }
serial8250_rx_dma(struct uart_8250_port * p)373 static inline int serial8250_rx_dma(struct uart_8250_port *p)
374 {
375 return -1;
376 }
serial8250_rx_dma_flush(struct uart_8250_port * p)377 static inline void serial8250_rx_dma_flush(struct uart_8250_port *p) { }
serial8250_request_dma(struct uart_8250_port * p)378 static inline int serial8250_request_dma(struct uart_8250_port *p)
379 {
380 return -1;
381 }
serial8250_release_dma(struct uart_8250_port * p)382 static inline void serial8250_release_dma(struct uart_8250_port *p) { }
383 #endif
384
ns16550a_goto_highspeed(struct uart_8250_port * up)385 static inline int ns16550a_goto_highspeed(struct uart_8250_port *up)
386 {
387 unsigned char status;
388
389 status = serial_in(up, 0x04); /* EXCR2 */
390 #define PRESL(x) ((x) & 0x30)
391 if (PRESL(status) == 0x10) {
392 /* already in high speed mode */
393 return 0;
394 } else {
395 status &= ~0xB0; /* Disable LOCK, mask out PRESL[01] */
396 status |= 0x10; /* 1.625 divisor for baud_base --> 921600 */
397 serial_out(up, 0x04, status);
398 }
399 return 1;
400 }
401
serial_index(struct uart_port * port)402 static inline int serial_index(struct uart_port *port)
403 {
404 return port->minor - 64;
405 }
406