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) 114 115 116 static inline int serial_in(struct uart_8250_port *up, int offset) 117 { 118 return up->port.serial_in(&up->port, offset); 119 } 120 121 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 * For the 16C950 128 */ 129 static void serial_icr_write(struct uart_8250_port *up, int offset, int value) 130 { 131 serial_out(up, UART_SCR, offset); 132 serial_out(up, UART_ICR, value); 133 } 134 135 static unsigned int __maybe_unused serial_icr_read(struct uart_8250_port *up, 136 int offset) 137 { 138 unsigned int value; 139 140 serial_icr_write(up, UART_ACR, up->acr | UART_ACR_ICRRD); 141 serial_out(up, UART_SCR, offset); 142 value = serial_in(up, UART_ICR); 143 serial_icr_write(up, UART_ACR, up->acr); 144 145 return value; 146 } 147 148 void serial8250_clear_and_reinit_fifos(struct uart_8250_port *p); 149 150 static inline int serial_dl_read(struct uart_8250_port *up) 151 { 152 return up->dl_read(up); 153 } 154 155 static inline void serial_dl_write(struct uart_8250_port *up, int value) 156 { 157 up->dl_write(up, value); 158 } 159 160 static inline bool serial8250_set_THRI(struct uart_8250_port *up) 161 { 162 if (up->ier & UART_IER_THRI) 163 return false; 164 up->ier |= UART_IER_THRI; 165 serial_out(up, UART_IER, up->ier); 166 return true; 167 } 168 169 static inline bool serial8250_clear_THRI(struct uart_8250_port *up) 170 { 171 if (!(up->ier & UART_IER_THRI)) 172 return false; 173 up->ier &= ~UART_IER_THRI; 174 serial_out(up, UART_IER, up->ier); 175 return true; 176 } 177 178 struct uart_8250_port *serial8250_get_port(int line); 179 180 void serial8250_rpm_get(struct uart_8250_port *p); 181 void serial8250_rpm_put(struct uart_8250_port *p); 182 183 void serial8250_rpm_get_tx(struct uart_8250_port *p); 184 void serial8250_rpm_put_tx(struct uart_8250_port *p); 185 186 int serial8250_em485_config(struct uart_port *port, struct serial_rs485 *rs485); 187 void serial8250_em485_start_tx(struct uart_8250_port *p); 188 void serial8250_em485_stop_tx(struct uart_8250_port *p); 189 void serial8250_em485_destroy(struct uart_8250_port *p); 190 191 /* MCR <-> TIOCM conversion */ 192 static inline int serial8250_TIOCM_to_MCR(int tiocm) 193 { 194 int mcr = 0; 195 196 if (tiocm & TIOCM_RTS) 197 mcr |= UART_MCR_RTS; 198 if (tiocm & TIOCM_DTR) 199 mcr |= UART_MCR_DTR; 200 if (tiocm & TIOCM_OUT1) 201 mcr |= UART_MCR_OUT1; 202 if (tiocm & TIOCM_OUT2) 203 mcr |= UART_MCR_OUT2; 204 if (tiocm & TIOCM_LOOP) 205 mcr |= UART_MCR_LOOP; 206 207 return mcr; 208 } 209 210 static inline int serial8250_MCR_to_TIOCM(int mcr) 211 { 212 int tiocm = 0; 213 214 if (mcr & UART_MCR_RTS) 215 tiocm |= TIOCM_RTS; 216 if (mcr & UART_MCR_DTR) 217 tiocm |= TIOCM_DTR; 218 if (mcr & UART_MCR_OUT1) 219 tiocm |= TIOCM_OUT1; 220 if (mcr & UART_MCR_OUT2) 221 tiocm |= TIOCM_OUT2; 222 if (mcr & UART_MCR_LOOP) 223 tiocm |= TIOCM_LOOP; 224 225 return tiocm; 226 } 227 228 /* MSR <-> TIOCM conversion */ 229 static inline int serial8250_MSR_to_TIOCM(int msr) 230 { 231 int tiocm = 0; 232 233 if (msr & UART_MSR_DCD) 234 tiocm |= TIOCM_CAR; 235 if (msr & UART_MSR_RI) 236 tiocm |= TIOCM_RNG; 237 if (msr & UART_MSR_DSR) 238 tiocm |= TIOCM_DSR; 239 if (msr & UART_MSR_CTS) 240 tiocm |= TIOCM_CTS; 241 242 return tiocm; 243 } 244 245 static inline void serial8250_out_MCR(struct uart_8250_port *up, int value) 246 { 247 serial_out(up, UART_MCR, value); 248 249 if (up->gpios) 250 mctrl_gpio_set(up->gpios, serial8250_MCR_to_TIOCM(value)); 251 } 252 253 static inline int serial8250_in_MCR(struct uart_8250_port *up) 254 { 255 int mctrl; 256 257 mctrl = serial_in(up, UART_MCR); 258 259 if (up->gpios) { 260 unsigned int mctrl_gpio = 0; 261 262 mctrl_gpio = mctrl_gpio_get_outputs(up->gpios, &mctrl_gpio); 263 mctrl |= serial8250_TIOCM_to_MCR(mctrl_gpio); 264 } 265 266 return mctrl; 267 } 268 269 bool alpha_jensen(void); 270 void alpha_jensen_set_mctrl(struct uart_port *port, unsigned int mctrl); 271 272 #ifdef CONFIG_SERIAL_8250_PNP 273 int serial8250_pnp_init(void); 274 void serial8250_pnp_exit(void); 275 #else 276 static inline int serial8250_pnp_init(void) { return 0; } 277 static inline void serial8250_pnp_exit(void) { } 278 #endif 279 280 #ifdef CONFIG_SERIAL_8250_FINTEK 281 int fintek_8250_probe(struct uart_8250_port *uart); 282 #else 283 static inline int fintek_8250_probe(struct uart_8250_port *uart) { return 0; } 284 #endif 285 286 #ifdef CONFIG_ARCH_OMAP1 287 #include <linux/soc/ti/omap1-soc.h> 288 static inline int is_omap1_8250(struct uart_8250_port *pt) 289 { 290 int res; 291 292 switch (pt->port.mapbase) { 293 case OMAP1_UART1_BASE: 294 case OMAP1_UART2_BASE: 295 case OMAP1_UART3_BASE: 296 res = 1; 297 break; 298 default: 299 res = 0; 300 break; 301 } 302 303 return res; 304 } 305 306 static inline int is_omap1510_8250(struct uart_8250_port *pt) 307 { 308 if (!cpu_is_omap1510()) 309 return 0; 310 311 return is_omap1_8250(pt); 312 } 313 #else 314 static inline int is_omap1_8250(struct uart_8250_port *pt) 315 { 316 return 0; 317 } 318 static inline int is_omap1510_8250(struct uart_8250_port *pt) 319 { 320 return 0; 321 } 322 #endif 323 324 #ifdef CONFIG_SERIAL_8250_DMA 325 extern int serial8250_tx_dma(struct uart_8250_port *); 326 extern int serial8250_rx_dma(struct uart_8250_port *); 327 extern void serial8250_rx_dma_flush(struct uart_8250_port *); 328 extern int serial8250_request_dma(struct uart_8250_port *); 329 extern void serial8250_release_dma(struct uart_8250_port *); 330 331 static inline void serial8250_do_prepare_tx_dma(struct uart_8250_port *p) 332 { 333 struct uart_8250_dma *dma = p->dma; 334 335 if (dma->prepare_tx_dma) 336 dma->prepare_tx_dma(p); 337 } 338 339 static inline void serial8250_do_prepare_rx_dma(struct uart_8250_port *p) 340 { 341 struct uart_8250_dma *dma = p->dma; 342 343 if (dma->prepare_rx_dma) 344 dma->prepare_rx_dma(p); 345 } 346 #else 347 static inline int serial8250_tx_dma(struct uart_8250_port *p) 348 { 349 return -1; 350 } 351 static inline int serial8250_rx_dma(struct uart_8250_port *p) 352 { 353 return -1; 354 } 355 static inline void serial8250_rx_dma_flush(struct uart_8250_port *p) { } 356 static inline int serial8250_request_dma(struct uart_8250_port *p) 357 { 358 return -1; 359 } 360 static inline void serial8250_release_dma(struct uart_8250_port *p) { } 361 #endif 362 363 static inline int ns16550a_goto_highspeed(struct uart_8250_port *up) 364 { 365 unsigned char status; 366 367 status = serial_in(up, 0x04); /* EXCR2 */ 368 #define PRESL(x) ((x) & 0x30) 369 if (PRESL(status) == 0x10) { 370 /* already in high speed mode */ 371 return 0; 372 } else { 373 status &= ~0xB0; /* Disable LOCK, mask out PRESL[01] */ 374 status |= 0x10; /* 1.625 divisor for baud_base --> 921600 */ 375 serial_out(up, 0x04, status); 376 } 377 return 1; 378 } 379 380 static inline int serial_index(struct uart_port *port) 381 { 382 return port->minor - 64; 383 } 384