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; 125 126 static inline int serial_in(struct uart_8250_port *up, int offset) 127 { 128 return up->port.serial_in(&up->port, offset); 129 } 130 131 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 */ 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 */ 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 } 164 165 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)); 184 185 static inline u32 serial_dl_read(struct uart_8250_port *up) 186 { 187 return up->dl_read(up); 188 } 189 190 static inline void serial_dl_write(struct uart_8250_port *up, u32 value) 191 { 192 up->dl_write(up, value); 193 } 194 195 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 } 206 207 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 */ 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 } 247 248 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 */ 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 } 282 283 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 } 290 291 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 311 static inline int serial8250_pnp_init(void) { return 0; } 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 322 static inline void univ8250_rsa_support(struct uart_ops *ops, const struct uart_ops *core_ops) { } 323 static inline void rsa_enable(struct uart_8250_port *up) {} 324 static inline void rsa_disable(struct uart_8250_port *up) {} 325 static inline void rsa_autoconfig(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 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> 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 } 354 355 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 363 static inline int is_omap1_8250(struct uart_8250_port *pt) 364 { 365 return 0; 366 } 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 *); 380 381 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 } 388 389 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 } 396 397 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 404 static inline int serial8250_tx_dma(struct uart_8250_port *p) 405 { 406 return -1; 407 } 408 static inline void serial8250_tx_dma_flush(struct uart_8250_port *p) { } 409 static inline int serial8250_rx_dma(struct uart_8250_port *p) 410 { 411 return -1; 412 } 413 static inline void serial8250_rx_dma_flush(struct uart_8250_port *p) { } 414 static inline int serial8250_request_dma(struct uart_8250_port *p) 415 { 416 return -1; 417 } 418 static inline void serial8250_release_dma(struct uart_8250_port *p) { } 419 420 static inline bool serial8250_tx_dma_running(struct uart_8250_port *p) 421 { 422 return false; 423 } 424 #endif 425 426 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 } 442 443 static inline int serial_index(struct uart_port *port) 444 { 445 return port->minor - 64; 446 } 447