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