drivers/serial/serial_pl01x.c

   1 /*
   2  * (C) Copyright 2000
   3  * Rob Taylor, Flying Pig Systems. robt@flyingpig.com.
   4  *
   5  * (C) Copyright 2004
   6  * ARM Ltd.
   7  * Philippe Robin, <philippe.robin@arm.com>
   8  *
   9  * SPDX-License-Identifier:     GPL-2.0+
  10  */
  11
  12 /* Simple U-Boot driver for the PrimeCell PL010/PL011 UARTs */
  13
  14 #include <common.h>
  15 #include <dm.h>
  16 #include <errno.h>
  17 #include <watchdog.h>
  18 #include <asm/io.h>
  19 #include <serial.h>
  20 #include <dm/platform_data/serial_pl01x.h>
  21 #include <linux/compiler.h>
  22 #include "serial_pl01x_internal.h"
  23 #include <fdtdec.h>
  24
  25 DECLARE_GLOBAL_DATA_PTR;
  26
  27 #ifndef CONFIG_DM_SERIAL
  28
  29 static volatile unsigned char *const port[] = CONFIG_PL01x_PORTS;
  30 static enum pl01x_type pl01x_type __attribute__ ((section(".data")));
  31 static struct pl01x_regs *base_regs __attribute__ ((section(".data")));
  32 #define NUM_PORTS (sizeof(port)/sizeof(port[0]))
  33
  34 #endif
  35
  36 static int pl01x_putc(struct pl01x_regs *regs, char c)
  37 {
  38         /* Wait until there is space in the FIFO */
  39         if (readl(&regs->fr) & UART_PL01x_FR_TXFF)
  40                 return -EAGAIN;
  41
  42         /* Send the character */
  43         writel(c, &regs->dr);
  44
  45         return 0;
  46 }
  47
  48 static int pl01x_getc(struct pl01x_regs *regs)
  49 {
  50         unsigned int data;
  51
  52         /* Wait until there is data in the FIFO */
  53         if (readl(&regs->fr) & UART_PL01x_FR_RXFE)
  54                 return -EAGAIN;
  55
  56         data = readl(&regs->dr);
  57
  58         /* Check for an error flag */
  59         if (data & 0xFFFFFF00) {
  60                 /* Clear the error */
  61                 writel(0xFFFFFFFF, &regs->ecr);
  62                 return -1;
  63         }
  64
  65         return (int) data;
  66 }
  67
  68 static int pl01x_tstc(struct pl01x_regs *regs)
  69 {
  70         WATCHDOG_RESET();
  71         return !(readl(&regs->fr) & UART_PL01x_FR_RXFE);
  72 }
  73
  74 static int pl01x_generic_serial_init(struct pl01x_regs *regs,
  75                                      enum pl01x_type type)
  76 {
  77         switch (type) {
  78         case TYPE_PL010:
  79                 /* disable everything */
  80                 writel(0, &regs->pl010_cr);
  81                 break;
  82         case TYPE_PL011:
  83                 /* disable everything */
  84                 writel(0, &regs->pl011_cr);
  85                 break;
  86         default:
  87                 return -EINVAL;
  88         }
  89
  90         return 0;
  91 }
  92
  93 static int pl011_set_line_control(struct pl01x_regs *regs)
  94 {
  95         unsigned int lcr;
  96         /*
  97          * Internal update of baud rate register require line
  98          * control register write
  99          */
 100         lcr = UART_PL011_LCRH_WLEN_8 | UART_PL011_LCRH_FEN;
 101         writel(lcr, &regs->pl011_lcrh);
 102         return 0;
 103 }
 104
 105 static int pl01x_generic_setbrg(struct pl01x_regs *regs, enum pl01x_type type,
 106                                 int clock, int baudrate)
 107 {
 108         switch (type) {
 109         case TYPE_PL010: {
 110                 unsigned int divisor;
 111
 112                 /* disable everything */
 113                 writel(0, &regs->pl010_cr);
 114
 115                 switch (baudrate) {
 116                 case 9600:
 117                         divisor = UART_PL010_BAUD_9600;
 118                         break;
 119                 case 19200:
 120                         divisor = UART_PL010_BAUD_19200;
 121                         break;
 122                 case 38400:
 123                         divisor = UART_PL010_BAUD_38400;
 124                         break;
 125                 case 57600:
 126                         divisor = UART_PL010_BAUD_57600;
 127                         break;
 128                 case 115200:
 129                         divisor = UART_PL010_BAUD_115200;
 130                         break;
 131                 default:
 132                         divisor = UART_PL010_BAUD_38400;
 133                 }
 134
 135                 writel((divisor & 0xf00) >> 8, &regs->pl010_lcrm);
 136                 writel(divisor & 0xff, &regs->pl010_lcrl);
 137
 138                 /*
 139                  * Set line control for the PL010 to be 8 bits, 1 stop bit,
 140                  * no parity, fifo enabled
 141                  */
 142                 writel(UART_PL010_LCRH_WLEN_8 | UART_PL010_LCRH_FEN,
 143                        &regs->pl010_lcrh);
 144                 /* Finally, enable the UART */
 145                 writel(UART_PL010_CR_UARTEN, &regs->pl010_cr);
 146                 break;
 147         }
 148         case TYPE_PL011: {
 149                 unsigned int temp;
 150                 unsigned int divider;
 151                 unsigned int remainder;
 152                 unsigned int fraction;
 153
 154                 /*
 155                 * Set baud rate
 156                 *
 157                 * IBRD = UART_CLK / (16 * BAUD_RATE)
 158                 * FBRD = RND((64 * MOD(UART_CLK,(16 * BAUD_RATE)))
 159                 *               / (16 * BAUD_RATE))
 160                 */
 161                 temp = 16 * baudrate;
 162                 divider = clock / temp;
 163                 remainder = clock % temp;
 164                 temp = (8 * remainder) / baudrate;
 165                 fraction = (temp >> 1) + (temp & 1);
 166
 167                 writel(divider, &regs->pl011_ibrd);
 168                 writel(fraction, &regs->pl011_fbrd);
 169
 170                 pl011_set_line_control(regs);
 171                 /* Finally, enable the UART */
 172                 writel(UART_PL011_CR_UARTEN | UART_PL011_CR_TXE |
 173                        UART_PL011_CR_RXE | UART_PL011_CR_RTS, &regs->pl011_cr);
 174                 break;
 175         }
 176         default:
 177                 return -EINVAL;
 178         }
 179
 180         return 0;
 181 }
 182
 183 #ifndef CONFIG_DM_SERIAL
 184 static void pl01x_serial_init_baud(int baudrate)
 185 {
 186         int clock = 0;
 187
 188 #if defined(CONFIG_PL010_SERIAL)
 189         pl01x_type = TYPE_PL010;
 190 #elif defined(CONFIG_PL011_SERIAL)
 191         pl01x_type = TYPE_PL011;
 192         clock = CONFIG_PL011_CLOCK;
 193 #endif
 194         base_regs = (struct pl01x_regs *)port[CONFIG_CONS_INDEX];
 195
 196         pl01x_generic_serial_init(base_regs, pl01x_type);
 197         pl01x_generic_setbrg(base_regs, pl01x_type, clock, baudrate);
 198 }
 199
 200 /*
 201  * Integrator AP has two UARTs, we use the first one, at 38400-8-N-1
 202  * Integrator CP has two UARTs, use the first one, at 38400-8-N-1
 203  * Versatile PB has four UARTs.
 204  */
 205 int pl01x_serial_init(void)
 206 {
 207         pl01x_serial_init_baud(CONFIG_BAUDRATE);
 208
 209         return 0;
 210 }
 211
 212 static void pl01x_serial_putc(const char c)
 213 {
 214         if (c == '\n')
 215                 while (pl01x_putc(base_regs, '\r') == -EAGAIN);
 216
 217         while (pl01x_putc(base_regs, c) == -EAGAIN);
 218 }
 219
 220 static int pl01x_serial_getc(void)
 221 {
 222         while (1) {
 223                 int ch = pl01x_getc(base_regs);
 224
 225                 if (ch == -EAGAIN) {
 226                         WATCHDOG_RESET();
 227                         continue;
 228                 }
 229
 230                 return ch;
 231         }
 232 }
 233
 234 static int pl01x_serial_tstc(void)
 235 {
 236         return pl01x_tstc(base_regs);
 237 }
 238
 239 static void pl01x_serial_setbrg(void)
 240 {
 241         /*
 242          * Flush FIFO and wait for non-busy before changing baudrate to avoid
 243          * crap in console
 244          */
 245         while (!(readl(&base_regs->fr) & UART_PL01x_FR_TXFE))
 246                 WATCHDOG_RESET();
 247         while (readl(&base_regs->fr) & UART_PL01x_FR_BUSY)
 248                 WATCHDOG_RESET();
 249         pl01x_serial_init_baud(gd->baudrate);
 250 }
 251
 252 static struct serial_device pl01x_serial_drv = {
 253         .name   = "pl01x_serial",
 254         .start  = pl01x_serial_init,
 255         .stop   = NULL,
 256         .setbrg = pl01x_serial_setbrg,
 257         .putc   = pl01x_serial_putc,
 258         .puts   = default_serial_puts,
 259         .getc   = pl01x_serial_getc,
 260         .tstc   = pl01x_serial_tstc,
 261 };
 262
 263 void pl01x_serial_initialize(void)
 264 {
 265         serial_register(&pl01x_serial_drv);
 266 }
 267
 268 __weak struct serial_device *default_serial_console(void)
 269 {
 270         return &pl01x_serial_drv;
 271 }
 272
 273 #endif /* nCONFIG_DM_SERIAL */
 274
 275 #ifdef CONFIG_DM_SERIAL
 276
 277 struct pl01x_priv {
 278         struct pl01x_regs *regs;
 279         enum pl01x_type type;
 280 };
 281
 282 static int pl01x_serial_setbrg(struct udevice *dev, int baudrate)
 283 {
 284         struct pl01x_serial_platdata *plat = dev_get_platdata(dev);
 285         struct pl01x_priv *priv = dev_get_priv(dev);
 286
 287         if (!plat->skip_init) {
 288                 pl01x_generic_setbrg(priv->regs, priv->type, plat->clock,
 289                                      baudrate);
 290         }
 291
 292         return 0;
 293 }
 294
 295 static int pl01x_serial_probe(struct udevice *dev)
 296 {
 297         struct pl01x_serial_platdata *plat = dev_get_platdata(dev);
 298         struct pl01x_priv *priv = dev_get_priv(dev);
 299
 300         priv->regs = (struct pl01x_regs *)plat->base;
 301         priv->type = plat->type;
 302         if (!plat->skip_init)
 303                 return pl01x_generic_serial_init(priv->regs, priv->type);
 304         else
 305                 return 0;
 306 }
 307
 308 static int pl01x_serial_getc(struct udevice *dev)
 309 {
 310         struct pl01x_priv *priv = dev_get_priv(dev);
 311
 312         return pl01x_getc(priv->regs);
 313 }
 314
 315 static int pl01x_serial_putc(struct udevice *dev, const char ch)
 316 {
 317         struct pl01x_priv *priv = dev_get_priv(dev);
 318
 319         return pl01x_putc(priv->regs, ch);
 320 }
 321
 322 static int pl01x_serial_pending(struct udevice *dev, bool input)
 323 {
 324         struct pl01x_priv *priv = dev_get_priv(dev);
 325         unsigned int fr = readl(&priv->regs->fr);
 326
 327         if (input)
 328                 return pl01x_tstc(priv->regs);
 329         else
 330                 return fr & UART_PL01x_FR_TXFF ? 0 : 1;
 331 }
 332
 333 static const struct dm_serial_ops pl01x_serial_ops = {
 334         .putc = pl01x_serial_putc,
 335         .pending = pl01x_serial_pending,
 336         .getc = pl01x_serial_getc,
 337         .setbrg = pl01x_serial_setbrg,
 338 };
 339
 340 #if CONFIG_IS_ENABLED(OF_CONTROL)
 341 static const struct udevice_id pl01x_serial_id[] ={
 342         {.compatible = "arm,pl011", .data = TYPE_PL011},
 343         {.compatible = "arm,pl010", .data = TYPE_PL010},
 344         {}
 345 };
 346
 347 static int pl01x_serial_ofdata_to_platdata(struct udevice *dev)
 348 {
 349         struct pl01x_serial_platdata *plat = dev_get_platdata(dev);
 350         fdt_addr_t addr;
 351
 352         addr = dev_get_addr(dev);
 353         if (addr == FDT_ADDR_T_NONE)
 354                 return -EINVAL;
 355
 356         plat->base = addr;
 357         plat->clock = fdtdec_get_int(gd->fdt_blob, dev_of_offset(dev), "clock",
 358                                      1);
 359         plat->type = dev_get_driver_data(dev);
 360         plat->skip_init = fdtdec_get_bool(gd->fdt_blob, dev_of_offset(dev),
 361                                           "skip-init");
 362         return 0;
 363 }
 364 #endif
 365
 366 U_BOOT_DRIVER(serial_pl01x) = {
 367         .name   = "serial_pl01x",
 368         .id     = UCLASS_SERIAL,
 369         .of_match = of_match_ptr(pl01x_serial_id),
 370         .ofdata_to_platdata = of_match_ptr(pl01x_serial_ofdata_to_platdata),
 371         .platdata_auto_alloc_size = sizeof(struct pl01x_serial_platdata),
 372         .probe = pl01x_serial_probe,
 373         .ops    = &pl01x_serial_ops,
 374         .flags = DM_FLAG_PRE_RELOC,
 375         .priv_auto_alloc_size = sizeof(struct pl01x_priv),
 376 };
 377
 378 #endif
 379
 380 #if defined(CONFIG_DEBUG_UART_PL010) || defined(CONFIG_DEBUG_UART_PL011)
 381
 382 #include <debug_uart.h>
 383
 384 static void _debug_uart_init(void)
 385 {
 386 #ifndef CONFIG_DEBUG_UART_SKIP_INIT
 387         struct pl01x_regs *regs = (struct pl01x_regs *)CONFIG_DEBUG_UART_BASE;
 388         enum pl01x_type type = CONFIG_IS_ENABLED(DEBUG_UART_PL011) ?
 389                                 TYPE_PL011 : TYPE_PL010;
 390
 391         pl01x_generic_serial_init(regs, type);
 392         pl01x_generic_setbrg(regs, type,
 393                              CONFIG_DEBUG_UART_CLOCK, CONFIG_BAUDRATE);
 394 #endif
 395 }
 396
 397 static inline void _debug_uart_putc(int ch)
 398 {
 399         struct pl01x_regs *regs = (struct pl01x_regs *)CONFIG_DEBUG_UART_BASE;
 400
 401         pl01x_putc(regs, ch);
 402 }
 403
 404 DEBUG_UART_FUNCS
 405
 406 #endif