drivers/serial/ns16550.c

   1 /*
   2  * COM1 NS16550 support
   3  * originally from linux source (arch/powerpc/boot/ns16550.c)
   4  * modified to use CONFIG_SYS_ISA_MEM and new defines
   5  */
   6
   7 #include <common.h>
   8 #include <dm.h>
   9 #include <errno.h>
  10 #include <fdtdec.h>
  11 #include <ns16550.h>
  12 #include <serial.h>
  13 #include <watchdog.h>
  14 #include <linux/types.h>
  15 #include <asm/io.h>
  16
  17 DECLARE_GLOBAL_DATA_PTR;
  18
  19 #define UART_LCRVAL UART_LCR_8N1                /* 8 data, 1 stop, no parity */
  20 #define UART_MCRVAL (UART_MCR_DTR | \
  21                      UART_MCR_RTS)              /* RTS/DTR */
  22 #define UART_FCRVAL (UART_FCR_FIFO_EN | \
  23                      UART_FCR_RXSR |    \
  24                      UART_FCR_TXSR)             /* Clear & enable FIFOs */
  25
  26 #ifndef CONFIG_DM_SERIAL
  27 #ifdef CONFIG_SYS_NS16550_PORT_MAPPED
  28 #define serial_out(x, y)        outb(x, (ulong)y)
  29 #define serial_in(y)            inb((ulong)y)
  30 #elif defined(CONFIG_SYS_NS16550_MEM32) && (CONFIG_SYS_NS16550_REG_SIZE > 0)
  31 #define serial_out(x, y)        out_be32(y, x)
  32 #define serial_in(y)            in_be32(y)
  33 #elif defined(CONFIG_SYS_NS16550_MEM32) && (CONFIG_SYS_NS16550_REG_SIZE < 0)
  34 #define serial_out(x, y)        out_le32(y, x)
  35 #define serial_in(y)            in_le32(y)
  36 #else
  37 #define serial_out(x, y)        writeb(x, y)
  38 #define serial_in(y)            readb(y)
  39 #endif
  40 #endif /* !CONFIG_DM_SERIAL */
  41
  42 #if defined(CONFIG_SOC_KEYSTONE)
  43 #define UART_REG_VAL_PWREMU_MGMT_UART_DISABLE   0
  44 #define UART_REG_VAL_PWREMU_MGMT_UART_ENABLE ((1 << 14) | (1 << 13) | (1 << 0))
  45 #undef UART_MCRVAL
  46 #ifdef CONFIG_SERIAL_HW_FLOW_CONTROL
  47 #define UART_MCRVAL             (UART_MCR_RTS | UART_MCR_AFE)
  48 #else
  49 #define UART_MCRVAL             (UART_MCR_RTS)
  50 #endif
  51 #endif
  52
  53 #ifndef CONFIG_SYS_NS16550_IER
  54 #define CONFIG_SYS_NS16550_IER  0x00
  55 #endif /* CONFIG_SYS_NS16550_IER */
  56
  57 static inline void serial_out_shift(void *addr, int shift, int value)
  58 {
  59 #ifdef CONFIG_SYS_NS16550_PORT_MAPPED
  60         outb(value, (ulong)addr);
  61 #elif defined(CONFIG_SYS_NS16550_MEM32) && !defined(CONFIG_SYS_BIG_ENDIAN)
  62         out_le32(addr, value);
  63 #elif defined(CONFIG_SYS_NS16550_MEM32) && defined(CONFIG_SYS_BIG_ENDIAN)
  64         out_be32(addr, value);
  65 #elif defined(CONFIG_SYS_NS16550_MEM32)
  66         writel(value, addr);
  67 #elif defined(CONFIG_SYS_BIG_ENDIAN)
  68         writeb(value, addr + (1 << shift) - 1);
  69 #else
  70         writeb(value, addr);
  71 #endif
  72 }
  73
  74 static inline int serial_in_shift(void *addr, int shift)
  75 {
  76 #ifdef CONFIG_SYS_NS16550_PORT_MAPPED
  77         return inb((ulong)addr);
  78 #elif defined(CONFIG_SYS_NS16550_MEM32) && !defined(CONFIG_SYS_BIG_ENDIAN)
  79         return in_le32(addr);
  80 #elif defined(CONFIG_SYS_NS16550_MEM32) && defined(CONFIG_SYS_BIG_ENDIAN)
  81         return in_be32(addr);
  82 #elif defined(CONFIG_SYS_NS16550_MEM32)
  83         return readl(addr);
  84 #elif defined(CONFIG_SYS_BIG_ENDIAN)
  85         return readb(addr + (1 << shift) - 1);
  86 #else
  87         return readb(addr);
  88 #endif
  89 }
  90
  91 #ifdef CONFIG_DM_SERIAL
  92
  93 #ifndef CONFIG_SYS_NS16550_CLK
  94 #define CONFIG_SYS_NS16550_CLK  0
  95 #endif
  96
  97 static void ns16550_writeb(NS16550_t port, int offset, int value)
  98 {
  99         struct ns16550_platdata *plat = port->plat;
 100         unsigned char *addr;
 101
 102         offset *= 1 << plat->reg_shift;
 103         addr = (unsigned char *)plat->base + offset;
 104
 105         /*
 106          * As far as we know it doesn't make sense to support selection of
 107          * these options at run-time, so use the existing CONFIG options.
 108          */
 109         serial_out_shift(addr + plat->reg_offset, plat->reg_shift, value);
 110 }
 111
 112 static int ns16550_readb(NS16550_t port, int offset)
 113 {
 114         struct ns16550_platdata *plat = port->plat;
 115         unsigned char *addr;
 116
 117         offset *= 1 << plat->reg_shift;
 118         addr = (unsigned char *)plat->base + offset;
 119
 120         return serial_in_shift(addr + plat->reg_offset, plat->reg_shift);
 121 }
 122
 123 /* We can clean these up once everything is moved to driver model */
 124 #define serial_out(value, addr) \
 125         ns16550_writeb(com_port, \
 126                 (unsigned char *)addr - (unsigned char *)com_port, value)
 127 #define serial_in(addr) \
 128         ns16550_readb(com_port, \
 129                 (unsigned char *)addr - (unsigned char *)com_port)
 130 #endif
 131
 132 int ns16550_calc_divisor(NS16550_t port, int clock, int baudrate)
 133 {
 134         const unsigned int mode_x_div = 16;
 135
 136         return DIV_ROUND_CLOSEST(clock, mode_x_div * baudrate);
 137 }
 138
 139 static void NS16550_setbrg(NS16550_t com_port, int baud_divisor)
 140 {
 141         serial_out(UART_LCR_BKSE | UART_LCRVAL, &com_port->lcr);
 142         serial_out(baud_divisor & 0xff, &com_port->dll);
 143         serial_out((baud_divisor >> 8) & 0xff, &com_port->dlm);
 144         serial_out(UART_LCRVAL, &com_port->lcr);
 145 }
 146
 147 void NS16550_init(NS16550_t com_port, int baud_divisor)
 148 {
 149 #if (defined(CONFIG_SPL_BUILD) && \
 150                 (defined(CONFIG_OMAP34XX) || defined(CONFIG_OMAP44XX)))
 151         /*
 152          * On some OMAP3/OMAP4 devices when UART3 is configured for boot mode
 153          * before SPL starts only THRE bit is set. We have to empty the
 154          * transmitter before initialization starts.
 155          */
 156         if ((serial_in(&com_port->lsr) & (UART_LSR_TEMT | UART_LSR_THRE))
 157              == UART_LSR_THRE) {
 158                 if (baud_divisor != -1)
 159                         NS16550_setbrg(com_port, baud_divisor);
 160                 serial_out(0, &com_port->mdr1);
 161         }
 162 #endif
 163
 164         while (!(serial_in(&com_port->lsr) & UART_LSR_TEMT))
 165                 ;
 166
 167         serial_out(CONFIG_SYS_NS16550_IER, &com_port->ier);
 168 #if defined(CONFIG_OMAP) || defined(CONFIG_AM33XX) || \
 169                         defined(CONFIG_TI81XX) || defined(CONFIG_AM43XX)
 170         serial_out(0x7, &com_port->mdr1);       /* mode select reset TL16C750*/
 171 #endif
 172         serial_out(UART_MCRVAL, &com_port->mcr);
 173         serial_out(UART_FCRVAL, &com_port->fcr);
 174         if (baud_divisor != -1)
 175                 NS16550_setbrg(com_port, baud_divisor);
 176 #if defined(CONFIG_OMAP) || \
 177         defined(CONFIG_AM33XX) || defined(CONFIG_SOC_DA8XX) || \
 178         defined(CONFIG_TI81XX) || defined(CONFIG_AM43XX)
 179
 180         /* /16 is proper to hit 115200 with 48MHz */
 181         serial_out(0, &com_port->mdr1);
 182 #endif /* CONFIG_OMAP */
 183 #if defined(CONFIG_SOC_KEYSTONE)
 184         serial_out(UART_REG_VAL_PWREMU_MGMT_UART_ENABLE, &com_port->regC);
 185 #endif
 186 }
 187
 188 #ifndef CONFIG_NS16550_MIN_FUNCTIONS
 189 void NS16550_reinit(NS16550_t com_port, int baud_divisor)
 190 {
 191         serial_out(CONFIG_SYS_NS16550_IER, &com_port->ier);
 192         NS16550_setbrg(com_port, 0);
 193         serial_out(UART_MCRVAL, &com_port->mcr);
 194         serial_out(UART_FCRVAL, &com_port->fcr);
 195         NS16550_setbrg(com_port, baud_divisor);
 196 }
 197 #endif /* CONFIG_NS16550_MIN_FUNCTIONS */
 198
 199 void NS16550_putc(NS16550_t com_port, char c)
 200 {
 201         while ((serial_in(&com_port->lsr) & UART_LSR_THRE) == 0)
 202                 ;
 203         serial_out(c, &com_port->thr);
 204
 205         /*
 206          * Call watchdog_reset() upon newline. This is done here in putc
 207          * since the environment code uses a single puts() to print the complete
 208          * environment upon "printenv". So we can't put this watchdog call
 209          * in puts().
 210          */
 211         if (c == '\n')
 212                 WATCHDOG_RESET();
 213 }
 214
 215 #ifndef CONFIG_NS16550_MIN_FUNCTIONS
 216 char NS16550_getc(NS16550_t com_port)
 217 {
 218         while ((serial_in(&com_port->lsr) & UART_LSR_DR) == 0) {
 219 #if !defined(CONFIG_SPL_BUILD) && defined(CONFIG_USB_TTY)
 220                 extern void usbtty_poll(void);
 221                 usbtty_poll();
 222 #endif
 223                 WATCHDOG_RESET();
 224         }
 225         return serial_in(&com_port->rbr);
 226 }
 227
 228 int NS16550_tstc(NS16550_t com_port)
 229 {
 230         return (serial_in(&com_port->lsr) & UART_LSR_DR) != 0;
 231 }
 232
 233 #endif /* CONFIG_NS16550_MIN_FUNCTIONS */
 234
 235 #ifdef CONFIG_DEBUG_UART_NS16550
 236
 237 #include <debug_uart.h>
 238
 239 #define serial_dout(reg, value) \
 240         serial_out_shift((char *)com_port + \
 241                 ((char *)reg - (char *)com_port) * \
 242                         (1 << CONFIG_DEBUG_UART_SHIFT), \
 243                 CONFIG_DEBUG_UART_SHIFT, value)
 244 #define serial_din(reg) \
 245         serial_in_shift((char *)com_port + \
 246                 ((char *)reg - (char *)com_port) * \
 247                         (1 << CONFIG_DEBUG_UART_SHIFT), \
 248                 CONFIG_DEBUG_UART_SHIFT)
 249
 250 static inline void _debug_uart_init(void)
 251 {
 252         struct NS16550 *com_port = (struct NS16550 *)CONFIG_DEBUG_UART_BASE;
 253         int baud_divisor;
 254
 255         /*
 256          * We copy the code from above because it is already horribly messy.
 257          * Trying to refactor to nicely remove the duplication doesn't seem
 258          * feasible. The better fix is to move all users of this driver to
 259          * driver model.
 260          */
 261         baud_divisor = ns16550_calc_divisor(com_port, CONFIG_DEBUG_UART_CLOCK,
 262                                             CONFIG_BAUDRATE);
 263         serial_dout(&com_port->ier, CONFIG_SYS_NS16550_IER);
 264         serial_dout(&com_port->mcr, UART_MCRVAL);
 265         serial_dout(&com_port->fcr, UART_FCRVAL);
 266
 267         serial_dout(&com_port->lcr, UART_LCR_BKSE | UART_LCRVAL);
 268         serial_dout(&com_port->dll, baud_divisor & 0xff);
 269         serial_dout(&com_port->dlm, (baud_divisor >> 8) & 0xff);
 270         serial_dout(&com_port->lcr, UART_LCRVAL);
 271 }
 272
 273 static inline void _debug_uart_putc(int ch)
 274 {
 275         struct NS16550 *com_port = (struct NS16550 *)CONFIG_DEBUG_UART_BASE;
 276
 277         while (!(serial_din(&com_port->lsr) & UART_LSR_THRE))
 278                 ;
 279         serial_dout(&com_port->thr, ch);
 280 }
 281
 282 DEBUG_UART_FUNCS
 283
 284 #endif
 285
 286 #ifdef CONFIG_DM_SERIAL
 287 static int ns16550_serial_putc(struct udevice *dev, const char ch)
 288 {
 289         struct NS16550 *const com_port = dev_get_priv(dev);
 290
 291         if (!(serial_in(&com_port->lsr) & UART_LSR_THRE))
 292                 return -EAGAIN;
 293         serial_out(ch, &com_port->thr);
 294
 295         /*
 296          * Call watchdog_reset() upon newline. This is done here in putc
 297          * since the environment code uses a single puts() to print the complete
 298          * environment upon "printenv". So we can't put this watchdog call
 299          * in puts().
 300          */
 301         if (ch == '\n')
 302                 WATCHDOG_RESET();
 303
 304         return 0;
 305 }
 306
 307 static int ns16550_serial_pending(struct udevice *dev, bool input)
 308 {
 309         struct NS16550 *const com_port = dev_get_priv(dev);
 310
 311         if (input)
 312                 return serial_in(&com_port->lsr) & UART_LSR_DR ? 1 : 0;
 313         else
 314                 return serial_in(&com_port->lsr) & UART_LSR_THRE ? 0 : 1;
 315 }
 316
 317 static int ns16550_serial_getc(struct udevice *dev)
 318 {
 319         struct NS16550 *const com_port = dev_get_priv(dev);
 320
 321         if (!(serial_in(&com_port->lsr) & UART_LSR_DR))
 322                 return -EAGAIN;
 323
 324         return serial_in(&com_port->rbr);
 325 }
 326
 327 static int ns16550_serial_setbrg(struct udevice *dev, int baudrate)
 328 {
 329         struct NS16550 *const com_port = dev_get_priv(dev);
 330         struct ns16550_platdata *plat = com_port->plat;
 331         int clock_divisor;
 332
 333         clock_divisor = ns16550_calc_divisor(com_port, plat->clock, baudrate);
 334
 335         NS16550_setbrg(com_port, clock_divisor);
 336
 337         return 0;
 338 }
 339
 340 int ns16550_serial_probe(struct udevice *dev)
 341 {
 342         struct NS16550 *const com_port = dev_get_priv(dev);
 343
 344         com_port->plat = dev_get_platdata(dev);
 345         NS16550_init(com_port, -1);
 346
 347         return 0;
 348 }
 349
 350 #if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)
 351 int ns16550_serial_ofdata_to_platdata(struct udevice *dev)
 352 {
 353         struct ns16550_platdata *plat = dev->platdata;
 354         fdt_addr_t addr;
 355
 356         /* try Processor Local Bus device first */
 357         addr = dev_get_addr(dev);
 358 #if defined(CONFIG_PCI) && defined(CONFIG_DM_PCI)
 359         if (addr == FDT_ADDR_T_NONE) {
 360                 /* then try pci device */
 361                 struct fdt_pci_addr pci_addr;
 362                 u32 bar;
 363                 int ret;
 364
 365                 /* we prefer to use a memory-mapped register */
 366                 ret = fdtdec_get_pci_addr(gd->fdt_blob, dev->of_offset,
 367                                           FDT_PCI_SPACE_MEM32, "reg",
 368                                           &pci_addr);
 369                 if (ret) {
 370                         /* try if there is any i/o-mapped register */
 371                         ret = fdtdec_get_pci_addr(gd->fdt_blob,
 372                                                   dev->of_offset,
 373                                                   FDT_PCI_SPACE_IO,
 374                                                   "reg", &pci_addr);
 375                         if (ret)
 376                                 return ret;
 377                 }
 378
 379                 ret = fdtdec_get_pci_bar32(dev, &pci_addr, &bar);
 380                 if (ret)
 381                         return ret;
 382
 383                 addr = bar;
 384         }
 385 #endif
 386
 387         if (addr == FDT_ADDR_T_NONE)
 388                 return -EINVAL;
 389
 390 #ifdef CONFIG_SYS_NS16550_PORT_MAPPED
 391         plat->base = addr;
 392 #else
 393         plat->base = (unsigned long)map_physmem(addr, 0, MAP_NOCACHE);
 394 #endif
 395
 396         plat->reg_offset = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
 397                                      "reg-offset", 0);
 398         plat->reg_shift = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
 399                                          "reg-shift", 0);
 400         plat->clock = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
 401                                      "clock-frequency",
 402                                      CONFIG_SYS_NS16550_CLK);
 403         if (!plat->clock) {
 404                 debug("ns16550 clock not defined\n");
 405                 return -EINVAL;
 406         }
 407
 408         return 0;
 409 }
 410 #endif
 411
 412 const struct dm_serial_ops ns16550_serial_ops = {
 413         .putc = ns16550_serial_putc,
 414         .pending = ns16550_serial_pending,
 415         .getc = ns16550_serial_getc,
 416         .setbrg = ns16550_serial_setbrg,
 417 };
 418
 419 #if !CONFIG_IS_ENABLED(OF_PLATDATA)
 420 #if CONFIG_IS_ENABLED(OF_CONTROL)
 421 /*
 422  * Please consider existing compatible strings before adding a new
 423  * one to keep this table compact. Or you may add a generic "ns16550"
 424  * compatible string to your dts.
 425  */
 426 static const struct udevice_id ns16550_serial_ids[] = {
 427         { .compatible = "ns16550" },
 428         { .compatible = "ns16550a" },
 429         { .compatible = "nvidia,tegra20-uart" },
 430         { .compatible = "snps,dw-apb-uart" },
 431         { .compatible = "ti,omap2-uart" },
 432         { .compatible = "ti,omap3-uart" },
 433         { .compatible = "ti,omap4-uart" },
 434         { .compatible = "ti,am3352-uart" },
 435         { .compatible = "ti,am4372-uart" },
 436         { .compatible = "ti,dra742-uart" },
 437         {}
 438 };
 439 #endif
 440
 441 #if CONFIG_IS_ENABLED(SERIAL_PRESENT)
 442 U_BOOT_DRIVER(ns16550_serial) = {
 443         .name   = "ns16550_serial",
 444         .id     = UCLASS_SERIAL,
 445 #if CONFIG_IS_ENABLED(OF_CONTROL)
 446         .of_match = ns16550_serial_ids,
 447         .ofdata_to_platdata = ns16550_serial_ofdata_to_platdata,
 448         .platdata_auto_alloc_size = sizeof(struct ns16550_platdata),
 449 #endif
 450         .priv_auto_alloc_size = sizeof(struct NS16550),
 451         .probe = ns16550_serial_probe,
 452         .ops    = &ns16550_serial_ops,
 453         .flags  = DM_FLAG_PRE_RELOC,
 454 };
 455 #endif
 456 #endif /* !OF_PLATDATA */
 457 #endif /* CONFIG_DM_SERIAL */