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 void serial8250_clear_and_reinit_fifos(struct uart_8250_port *p);
123
serial_dl_read(struct uart_8250_port * up)124 static inline int serial_dl_read(struct uart_8250_port *up)
125 {
126 return up->dl_read(up);
127 }
128
serial_dl_write(struct uart_8250_port * up,int value)129 static inline void serial_dl_write(struct uart_8250_port *up, int value)
130 {
131 up->dl_write(up, value);
132 }
133
serial8250_set_THRI(struct uart_8250_port * up)134 static inline bool serial8250_set_THRI(struct uart_8250_port *up)
135 {
136 if (up->ier & UART_IER_THRI)
137 return false;
138 up->ier |= UART_IER_THRI;
139 serial_out(up, UART_IER, up->ier);
140 return true;
141 }
142
serial8250_clear_THRI(struct uart_8250_port * up)143 static inline bool serial8250_clear_THRI(struct uart_8250_port *up)
144 {
145 if (!(up->ier & UART_IER_THRI))
146 return false;
147 up->ier &= ~UART_IER_THRI;
148 serial_out(up, UART_IER, up->ier);
149 return true;
150 }
151
152 struct uart_8250_port *serial8250_get_port(int line);
153
154 void serial8250_rpm_get(struct uart_8250_port *p);
155 void serial8250_rpm_put(struct uart_8250_port *p);
156
157 void serial8250_rpm_get_tx(struct uart_8250_port *p);
158 void serial8250_rpm_put_tx(struct uart_8250_port *p);
159
160 int serial8250_em485_config(struct uart_port *port, struct serial_rs485 *rs485);
161 void serial8250_em485_start_tx(struct uart_8250_port *p);
162 void serial8250_em485_stop_tx(struct uart_8250_port *p);
163 void serial8250_em485_destroy(struct uart_8250_port *p);
164
165 /* MCR <-> TIOCM conversion */
serial8250_TIOCM_to_MCR(int tiocm)166 static inline int serial8250_TIOCM_to_MCR(int tiocm)
167 {
168 int mcr = 0;
169
170 if (tiocm & TIOCM_RTS)
171 mcr |= UART_MCR_RTS;
172 if (tiocm & TIOCM_DTR)
173 mcr |= UART_MCR_DTR;
174 if (tiocm & TIOCM_OUT1)
175 mcr |= UART_MCR_OUT1;
176 if (tiocm & TIOCM_OUT2)
177 mcr |= UART_MCR_OUT2;
178 if (tiocm & TIOCM_LOOP)
179 mcr |= UART_MCR_LOOP;
180
181 return mcr;
182 }
183
serial8250_MCR_to_TIOCM(int mcr)184 static inline int serial8250_MCR_to_TIOCM(int mcr)
185 {
186 int tiocm = 0;
187
188 if (mcr & UART_MCR_RTS)
189 tiocm |= TIOCM_RTS;
190 if (mcr & UART_MCR_DTR)
191 tiocm |= TIOCM_DTR;
192 if (mcr & UART_MCR_OUT1)
193 tiocm |= TIOCM_OUT1;
194 if (mcr & UART_MCR_OUT2)
195 tiocm |= TIOCM_OUT2;
196 if (mcr & UART_MCR_LOOP)
197 tiocm |= TIOCM_LOOP;
198
199 return tiocm;
200 }
201
202 /* MSR <-> TIOCM conversion */
serial8250_MSR_to_TIOCM(int msr)203 static inline int serial8250_MSR_to_TIOCM(int msr)
204 {
205 int tiocm = 0;
206
207 if (msr & UART_MSR_DCD)
208 tiocm |= TIOCM_CAR;
209 if (msr & UART_MSR_RI)
210 tiocm |= TIOCM_RNG;
211 if (msr & UART_MSR_DSR)
212 tiocm |= TIOCM_DSR;
213 if (msr & UART_MSR_CTS)
214 tiocm |= TIOCM_CTS;
215
216 return tiocm;
217 }
218
serial8250_out_MCR(struct uart_8250_port * up,int value)219 static inline void serial8250_out_MCR(struct uart_8250_port *up, int value)
220 {
221 serial_out(up, UART_MCR, value);
222
223 if (up->gpios)
224 mctrl_gpio_set(up->gpios, serial8250_MCR_to_TIOCM(value));
225 }
226
serial8250_in_MCR(struct uart_8250_port * up)227 static inline int serial8250_in_MCR(struct uart_8250_port *up)
228 {
229 int mctrl;
230
231 mctrl = serial_in(up, UART_MCR);
232
233 if (up->gpios) {
234 unsigned int mctrl_gpio = 0;
235
236 mctrl_gpio = mctrl_gpio_get_outputs(up->gpios, &mctrl_gpio);
237 mctrl |= serial8250_TIOCM_to_MCR(mctrl_gpio);
238 }
239
240 return mctrl;
241 }
242
243 #if defined(__alpha__) && !defined(CONFIG_PCI)
244 /*
245 * Digital did something really horribly wrong with the OUT1 and OUT2
246 * lines on at least some ALPHA's. The failure mode is that if either
247 * is cleared, the machine locks up with endless interrupts.
248 */
249 #define ALPHA_KLUDGE_MCR (UART_MCR_OUT2 | UART_MCR_OUT1)
250 #else
251 #define ALPHA_KLUDGE_MCR 0
252 #endif
253
254 #ifdef CONFIG_SERIAL_8250_PNP
255 int serial8250_pnp_init(void);
256 void serial8250_pnp_exit(void);
257 #else
serial8250_pnp_init(void)258 static inline int serial8250_pnp_init(void) { return 0; }
serial8250_pnp_exit(void)259 static inline void serial8250_pnp_exit(void) { }
260 #endif
261
262 #ifdef CONFIG_SERIAL_8250_FINTEK
263 int fintek_8250_probe(struct uart_8250_port *uart);
264 #else
fintek_8250_probe(struct uart_8250_port * uart)265 static inline int fintek_8250_probe(struct uart_8250_port *uart) { return 0; }
266 #endif
267
268 #ifdef CONFIG_ARCH_OMAP1
is_omap1_8250(struct uart_8250_port * pt)269 static inline int is_omap1_8250(struct uart_8250_port *pt)
270 {
271 int res;
272
273 switch (pt->port.mapbase) {
274 case OMAP1_UART1_BASE:
275 case OMAP1_UART2_BASE:
276 case OMAP1_UART3_BASE:
277 res = 1;
278 break;
279 default:
280 res = 0;
281 break;
282 }
283
284 return res;
285 }
286
is_omap1510_8250(struct uart_8250_port * pt)287 static inline int is_omap1510_8250(struct uart_8250_port *pt)
288 {
289 if (!cpu_is_omap1510())
290 return 0;
291
292 return is_omap1_8250(pt);
293 }
294 #else
is_omap1_8250(struct uart_8250_port * pt)295 static inline int is_omap1_8250(struct uart_8250_port *pt)
296 {
297 return 0;
298 }
is_omap1510_8250(struct uart_8250_port * pt)299 static inline int is_omap1510_8250(struct uart_8250_port *pt)
300 {
301 return 0;
302 }
303 #endif
304
305 #ifdef CONFIG_SERIAL_8250_DMA
306 extern int serial8250_tx_dma(struct uart_8250_port *);
307 extern int serial8250_rx_dma(struct uart_8250_port *);
308 extern void serial8250_rx_dma_flush(struct uart_8250_port *);
309 extern int serial8250_request_dma(struct uart_8250_port *);
310 extern void serial8250_release_dma(struct uart_8250_port *);
311 #else
serial8250_tx_dma(struct uart_8250_port * p)312 static inline int serial8250_tx_dma(struct uart_8250_port *p)
313 {
314 return -1;
315 }
serial8250_rx_dma(struct uart_8250_port * p)316 static inline int serial8250_rx_dma(struct uart_8250_port *p)
317 {
318 return -1;
319 }
serial8250_rx_dma_flush(struct uart_8250_port * p)320 static inline void serial8250_rx_dma_flush(struct uart_8250_port *p) { }
serial8250_request_dma(struct uart_8250_port * p)321 static inline int serial8250_request_dma(struct uart_8250_port *p)
322 {
323 return -1;
324 }
serial8250_release_dma(struct uart_8250_port * p)325 static inline void serial8250_release_dma(struct uart_8250_port *p) { }
326 #endif
327
ns16550a_goto_highspeed(struct uart_8250_port * up)328 static inline int ns16550a_goto_highspeed(struct uart_8250_port *up)
329 {
330 unsigned char status;
331
332 status = serial_in(up, 0x04); /* EXCR2 */
333 #define PRESL(x) ((x) & 0x30)
334 if (PRESL(status) == 0x10) {
335 /* already in high speed mode */
336 return 0;
337 } else {
338 status &= ~0xB0; /* Disable LOCK, mask out PRESL[01] */
339 status |= 0x10; /* 1.625 divisor for baud_base --> 921600 */
340 serial_out(up, 0x04, status);
341 }
342 return 1;
343 }
344
serial_index(struct uart_port * port)345 static inline int serial_index(struct uart_port *port)
346 {
347 return port->minor - 64;
348 }
349