drivers/tty/serial/8250/8250.h

   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 }