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 92 93 #ifdef CONFIG_SERIAL_8250_SHARE_IRQ 94 #define SERIAL8250_SHARE_IRQS 1 95 #else 96 #define SERIAL8250_SHARE_IRQS 0 97 #endif 98 99 #define SERIAL8250_PORT_FLAGS(_base, _irq, _flags) \ 100 { \ 101 .iobase = _base, \ 102 .irq = _irq, \ 103 .uartclk = 1843200, \ 104 .iotype = UPIO_PORT, \ 105 .flags = UPF_BOOT_AUTOCONF | (_flags), \ 106 } 107 108 #define SERIAL8250_PORT(_base, _irq) SERIAL8250_PORT_FLAGS(_base, _irq, 0) 109 110 111 static inline int serial_in(struct uart_8250_port *up, int offset) 112 { 113 return up->port.serial_in(&up->port, offset); 114 } 115 116 static inline void serial_out(struct uart_8250_port *up, int offset, int value) 117 { 118 up->port.serial_out(&up->port, offset, value); 119 } 120 121 void serial8250_clear_and_reinit_fifos(struct uart_8250_port *p); 122 123 static inline int serial_dl_read(struct uart_8250_port *up) 124 { 125 return up->dl_read(up); 126 } 127 128 static inline void serial_dl_write(struct uart_8250_port *up, int value) 129 { 130 up->dl_write(up, value); 131 } 132 133 static inline bool serial8250_set_THRI(struct uart_8250_port *up) 134 { 135 if (up->ier & UART_IER_THRI) 136 return false; 137 up->ier |= UART_IER_THRI; 138 serial_out(up, UART_IER, up->ier); 139 return true; 140 } 141 142 static inline bool serial8250_clear_THRI(struct uart_8250_port *up) 143 { 144 if (!(up->ier & UART_IER_THRI)) 145 return false; 146 up->ier &= ~UART_IER_THRI; 147 serial_out(up, UART_IER, up->ier); 148 return true; 149 } 150 151 struct uart_8250_port *serial8250_get_port(int line); 152 153 void serial8250_rpm_get(struct uart_8250_port *p); 154 void serial8250_rpm_put(struct uart_8250_port *p); 155 156 void serial8250_rpm_get_tx(struct uart_8250_port *p); 157 void serial8250_rpm_put_tx(struct uart_8250_port *p); 158 159 int serial8250_em485_init(struct uart_8250_port *p); 160 void serial8250_em485_destroy(struct uart_8250_port *p); 161 162 /* MCR <-> TIOCM conversion */ 163 static inline int serial8250_TIOCM_to_MCR(int tiocm) 164 { 165 int mcr = 0; 166 167 if (tiocm & TIOCM_RTS) 168 mcr |= UART_MCR_RTS; 169 if (tiocm & TIOCM_DTR) 170 mcr |= UART_MCR_DTR; 171 if (tiocm & TIOCM_OUT1) 172 mcr |= UART_MCR_OUT1; 173 if (tiocm & TIOCM_OUT2) 174 mcr |= UART_MCR_OUT2; 175 if (tiocm & TIOCM_LOOP) 176 mcr |= UART_MCR_LOOP; 177 178 return mcr; 179 } 180 181 static inline int serial8250_MCR_to_TIOCM(int mcr) 182 { 183 int tiocm = 0; 184 185 if (mcr & UART_MCR_RTS) 186 tiocm |= TIOCM_RTS; 187 if (mcr & UART_MCR_DTR) 188 tiocm |= TIOCM_DTR; 189 if (mcr & UART_MCR_OUT1) 190 tiocm |= TIOCM_OUT1; 191 if (mcr & UART_MCR_OUT2) 192 tiocm |= TIOCM_OUT2; 193 if (mcr & UART_MCR_LOOP) 194 tiocm |= TIOCM_LOOP; 195 196 return tiocm; 197 } 198 199 /* MSR <-> TIOCM conversion */ 200 static inline int serial8250_MSR_to_TIOCM(int msr) 201 { 202 int tiocm = 0; 203 204 if (msr & UART_MSR_DCD) 205 tiocm |= TIOCM_CAR; 206 if (msr & UART_MSR_RI) 207 tiocm |= TIOCM_RNG; 208 if (msr & UART_MSR_DSR) 209 tiocm |= TIOCM_DSR; 210 if (msr & UART_MSR_CTS) 211 tiocm |= TIOCM_CTS; 212 213 return tiocm; 214 } 215 216 static inline void serial8250_out_MCR(struct uart_8250_port *up, int value) 217 { 218 serial_out(up, UART_MCR, value); 219 220 if (up->gpios) 221 mctrl_gpio_set(up->gpios, serial8250_MCR_to_TIOCM(value)); 222 } 223 224 static inline int serial8250_in_MCR(struct uart_8250_port *up) 225 { 226 int mctrl; 227 228 mctrl = serial_in(up, UART_MCR); 229 230 if (up->gpios) { 231 unsigned int mctrl_gpio = 0; 232 233 mctrl_gpio = mctrl_gpio_get_outputs(up->gpios, &mctrl_gpio); 234 mctrl |= serial8250_TIOCM_to_MCR(mctrl_gpio); 235 } 236 237 return mctrl; 238 } 239 240 #if defined(__alpha__) && !defined(CONFIG_PCI) 241 /* 242 * Digital did something really horribly wrong with the OUT1 and OUT2 243 * lines on at least some ALPHA's. The failure mode is that if either 244 * is cleared, the machine locks up with endless interrupts. 245 */ 246 #define ALPHA_KLUDGE_MCR (UART_MCR_OUT2 | UART_MCR_OUT1) 247 #else 248 #define ALPHA_KLUDGE_MCR 0 249 #endif 250 251 #ifdef CONFIG_SERIAL_8250_PNP 252 int serial8250_pnp_init(void); 253 void serial8250_pnp_exit(void); 254 #else 255 static inline int serial8250_pnp_init(void) { return 0; } 256 static inline void serial8250_pnp_exit(void) { } 257 #endif 258 259 #ifdef CONFIG_SERIAL_8250_FINTEK 260 int fintek_8250_probe(struct uart_8250_port *uart); 261 #else 262 static inline int fintek_8250_probe(struct uart_8250_port *uart) { return 0; } 263 #endif 264 265 #ifdef CONFIG_ARCH_OMAP1 266 static inline int is_omap1_8250(struct uart_8250_port *pt) 267 { 268 int res; 269 270 switch (pt->port.mapbase) { 271 case OMAP1_UART1_BASE: 272 case OMAP1_UART2_BASE: 273 case OMAP1_UART3_BASE: 274 res = 1; 275 break; 276 default: 277 res = 0; 278 break; 279 } 280 281 return res; 282 } 283 284 static inline int is_omap1510_8250(struct uart_8250_port *pt) 285 { 286 if (!cpu_is_omap1510()) 287 return 0; 288 289 return is_omap1_8250(pt); 290 } 291 #else 292 static inline int is_omap1_8250(struct uart_8250_port *pt) 293 { 294 return 0; 295 } 296 static inline int is_omap1510_8250(struct uart_8250_port *pt) 297 { 298 return 0; 299 } 300 #endif 301 302 #ifdef CONFIG_SERIAL_8250_DMA 303 extern int serial8250_tx_dma(struct uart_8250_port *); 304 extern int serial8250_rx_dma(struct uart_8250_port *); 305 extern void serial8250_rx_dma_flush(struct uart_8250_port *); 306 extern int serial8250_request_dma(struct uart_8250_port *); 307 extern void serial8250_release_dma(struct uart_8250_port *); 308 #else 309 static inline int serial8250_tx_dma(struct uart_8250_port *p) 310 { 311 return -1; 312 } 313 static inline int serial8250_rx_dma(struct uart_8250_port *p) 314 { 315 return -1; 316 } 317 static inline void serial8250_rx_dma_flush(struct uart_8250_port *p) { } 318 static inline int serial8250_request_dma(struct uart_8250_port *p) 319 { 320 return -1; 321 } 322 static inline void serial8250_release_dma(struct uart_8250_port *p) { } 323 #endif 324 325 static inline int ns16550a_goto_highspeed(struct uart_8250_port *up) 326 { 327 unsigned char status; 328 329 status = serial_in(up, 0x04); /* EXCR2 */ 330 #define PRESL(x) ((x) & 0x30) 331 if (PRESL(status) == 0x10) { 332 /* already in high speed mode */ 333 return 0; 334 } else { 335 status &= ~0xB0; /* Disable LOCK, mask out PRESL[01] */ 336 status |= 0x10; /* 1.625 divisor for baud_base --> 921600 */ 337 serial_out(up, 0x04, status); 338 } 339 return 1; 340 } 341 342 static inline int serial_index(struct uart_port *port) 343 { 344 return port->minor - 64; 345 } 346