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_config(struct uart_port *port, struct serial_rs485 *rs485);
 160 void serial8250_em485_start_tx(struct uart_8250_port *p);
 161 void serial8250_em485_stop_tx(struct uart_8250_port *p);
 162 void serial8250_em485_destroy(struct uart_8250_port *p);
 163
 164 /* MCR <-> TIOCM conversion */
 165 static inline int serial8250_TIOCM_to_MCR(int tiocm)
 166 {
 167         int mcr = 0;
 168
 169         if (tiocm & TIOCM_RTS)
 170                 mcr |= UART_MCR_RTS;
 171         if (tiocm & TIOCM_DTR)
 172                 mcr |= UART_MCR_DTR;
 173         if (tiocm & TIOCM_OUT1)
 174                 mcr |= UART_MCR_OUT1;
 175         if (tiocm & TIOCM_OUT2)
 176                 mcr |= UART_MCR_OUT2;
 177         if (tiocm & TIOCM_LOOP)
 178                 mcr |= UART_MCR_LOOP;
 179
 180         return mcr;
 181 }
 182
 183 static inline int serial8250_MCR_to_TIOCM(int mcr)
 184 {
 185         int tiocm = 0;
 186
 187         if (mcr & UART_MCR_RTS)
 188                 tiocm |= TIOCM_RTS;
 189         if (mcr & UART_MCR_DTR)
 190                 tiocm |= TIOCM_DTR;
 191         if (mcr & UART_MCR_OUT1)
 192                 tiocm |= TIOCM_OUT1;
 193         if (mcr & UART_MCR_OUT2)
 194                 tiocm |= TIOCM_OUT2;
 195         if (mcr & UART_MCR_LOOP)
 196                 tiocm |= TIOCM_LOOP;
 197
 198         return tiocm;
 199 }
 200
 201 /* MSR <-> TIOCM conversion */
 202 static inline int serial8250_MSR_to_TIOCM(int msr)
 203 {
 204         int tiocm = 0;
 205
 206         if (msr & UART_MSR_DCD)
 207                 tiocm |= TIOCM_CAR;
 208         if (msr & UART_MSR_RI)
 209                 tiocm |= TIOCM_RNG;
 210         if (msr & UART_MSR_DSR)
 211                 tiocm |= TIOCM_DSR;
 212         if (msr & UART_MSR_CTS)
 213                 tiocm |= TIOCM_CTS;
 214
 215         return tiocm;
 216 }
 217
 218 static inline void serial8250_out_MCR(struct uart_8250_port *up, int value)
 219 {
 220         serial_out(up, UART_MCR, value);
 221
 222         if (up->gpios)
 223                 mctrl_gpio_set(up->gpios, serial8250_MCR_to_TIOCM(value));
 224 }
 225
 226 static inline int serial8250_in_MCR(struct uart_8250_port *up)
 227 {
 228         int mctrl;
 229
 230         mctrl = serial_in(up, UART_MCR);
 231
 232         if (up->gpios) {
 233                 unsigned int mctrl_gpio = 0;
 234
 235                 mctrl_gpio = mctrl_gpio_get_outputs(up->gpios, &mctrl_gpio);
 236                 mctrl |= serial8250_TIOCM_to_MCR(mctrl_gpio);
 237         }
 238
 239         return mctrl;
 240 }
 241
 242 #if defined(__alpha__) && !defined(CONFIG_PCI)
 243 /*
 244  * Digital did something really horribly wrong with the OUT1 and OUT2
 245  * lines on at least some ALPHA's.  The failure mode is that if either
 246  * is cleared, the machine locks up with endless interrupts.
 247  */
 248 #define ALPHA_KLUDGE_MCR  (UART_MCR_OUT2 | UART_MCR_OUT1)
 249 #else
 250 #define ALPHA_KLUDGE_MCR 0
 251 #endif
 252
 253 #ifdef CONFIG_SERIAL_8250_PNP
 254 int serial8250_pnp_init(void);
 255 void serial8250_pnp_exit(void);
 256 #else
 257 static inline int serial8250_pnp_init(void) { return 0; }
 258 static inline void serial8250_pnp_exit(void) { }
 259 #endif
 260
 261 #ifdef CONFIG_SERIAL_8250_FINTEK
 262 int fintek_8250_probe(struct uart_8250_port *uart);
 263 #else
 264 static inline int fintek_8250_probe(struct uart_8250_port *uart) { return 0; }
 265 #endif
 266
 267 #ifdef CONFIG_ARCH_OMAP1
 268 static inline int is_omap1_8250(struct uart_8250_port *pt)
 269 {
 270         int res;
 271
 272         switch (pt->port.mapbase) {
 273         case OMAP1_UART1_BASE:
 274         case OMAP1_UART2_BASE:
 275         case OMAP1_UART3_BASE:
 276                 res = 1;
 277                 break;
 278         default:
 279                 res = 0;
 280                 break;
 281         }
 282
 283         return res;
 284 }
 285
 286 static inline int is_omap1510_8250(struct uart_8250_port *pt)
 287 {
 288         if (!cpu_is_omap1510())
 289                 return 0;
 290
 291         return is_omap1_8250(pt);
 292 }
 293 #else
 294 static inline int is_omap1_8250(struct uart_8250_port *pt)
 295 {
 296         return 0;
 297 }
 298 static inline int is_omap1510_8250(struct uart_8250_port *pt)
 299 {
 300         return 0;
 301 }
 302 #endif
 303
 304 #ifdef CONFIG_SERIAL_8250_DMA
 305 extern int serial8250_tx_dma(struct uart_8250_port *);
 306 extern int serial8250_rx_dma(struct uart_8250_port *);
 307 extern void serial8250_rx_dma_flush(struct uart_8250_port *);
 308 extern int serial8250_request_dma(struct uart_8250_port *);
 309 extern void serial8250_release_dma(struct uart_8250_port *);
 310 #else
 311 static inline int serial8250_tx_dma(struct uart_8250_port *p)
 312 {
 313         return -1;
 314 }
 315 static inline int serial8250_rx_dma(struct uart_8250_port *p)
 316 {
 317         return -1;
 318 }
 319 static inline void serial8250_rx_dma_flush(struct uart_8250_port *p) { }
 320 static inline int serial8250_request_dma(struct uart_8250_port *p)
 321 {
 322         return -1;
 323 }
 324 static inline void serial8250_release_dma(struct uart_8250_port *p) { }
 325 #endif
 326
 327 static inline int ns16550a_goto_highspeed(struct uart_8250_port *up)
 328 {
 329         unsigned char status;
 330
 331         status = serial_in(up, 0x04); /* EXCR2 */
 332 #define PRESL(x) ((x) & 0x30)
 333         if (PRESL(status) == 0x10) {
 334                 /* already in high speed mode */
 335                 return 0;
 336         } else {
 337                 status &= ~0xB0; /* Disable LOCK, mask out PRESL[01] */
 338                 status |= 0x10;  /* 1.625 divisor for baud_base --> 921600 */
 339                 serial_out(up, 0x04, status);
 340         }
 341         return 1;
 342 }
 343
 344 static inline int serial_index(struct uart_port *port)
 345 {
 346         return port->minor - 64;
 347 }