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 #ifdef CONFIG_DM_SERIAL
  58
  59 #ifndef CONFIG_SYS_NS16550_CLK
  60 #define CONFIG_SYS_NS16550_CLK  0
  61 #endif
  62
  63 static inline void serial_out_shift(void *addr, int shift, int value)
  64 {
  65 #ifdef CONFIG_SYS_NS16550_PORT_MAPPED
  66         outb(value, (ulong)addr);
  67 #elif defined(CONFIG_SYS_NS16550_MEM32) && !defined(CONFIG_SYS_BIG_ENDIAN)
  68         out_le32(addr, value);
  69 #elif defined(CONFIG_SYS_NS16550_MEM32) && defined(CONFIG_SYS_BIG_ENDIAN)
  70         out_be32(addr, value);
  71 #elif defined(CONFIG_SYS_NS16550_MEM32)
  72         writel(value, addr);
  73 #elif defined(CONFIG_SYS_BIG_ENDIAN)
  74         writeb(value, addr + (1 << shift) - 1);
  75 #else
  76         writeb(value, addr);
  77 #endif
  78 }
  79
  80 static inline int serial_in_shift(void *addr, int shift)
  81 {
  82 #ifdef CONFIG_SYS_NS16550_PORT_MAPPED
  83         return inb((ulong)addr);
  84 #elif defined(CONFIG_SYS_NS16550_MEM32) && !defined(CONFIG_SYS_BIG_ENDIAN)
  85         return in_le32(addr);
  86 #elif defined(CONFIG_SYS_NS16550_MEM32) && defined(CONFIG_SYS_BIG_ENDIAN)
  87         return in_be32(addr);
  88 #elif defined(CONFIG_SYS_NS16550_MEM32)
  89         return readl(addr);
  90 #elif defined(CONFIG_SYS_BIG_ENDIAN)
  91         return readb(addr + (1 << shift) - 1);
  92 #else
  93         return readb(addr);
  94 #endif
  95 }
  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 = map_physmem(plat->base, 0, MAP_NOCACHE) + offset;
 104         /*
 105          * As far as we know it doesn't make sense to support selection of
 106          * these options at run-time, so use the existing CONFIG options.
 107          */
 108         serial_out_shift(addr, plat->reg_shift, value);
 109 }
 110
 111 static int ns16550_readb(NS16550_t port, int offset)
 112 {
 113         struct ns16550_platdata *plat = port->plat;
 114         unsigned char *addr;
 115
 116         offset *= 1 << plat->reg_shift;
 117         addr = map_physmem(plat->base, 0, MAP_NOCACHE) + offset;
 118
 119         return serial_in_shift(addr, plat->reg_shift);
 120 }
 121
 122 /* We can clean these up once everything is moved to driver model */
 123 #define serial_out(value, addr) \
 124         ns16550_writeb(com_port, \
 125                 (unsigned char *)addr - (unsigned char *)com_port, value)
 126 #define serial_in(addr) \
 127         ns16550_readb(com_port, \
 128                 (unsigned char *)addr - (unsigned char *)com_port)
 129 #endif
 130
 131 static inline int calc_divisor(NS16550_t port, int clock, int baudrate)
 132 {
 133         const unsigned int mode_x_div = 16;
 134
 135         return DIV_ROUND_CLOSEST(clock, mode_x_div * baudrate);
 136 }
 137
 138 int ns16550_calc_divisor(NS16550_t port, int clock, int baudrate)
 139 {
 140 #ifdef CONFIG_OMAP1510
 141         /* If can't cleanly clock 115200 set div to 1 */
 142         if ((clock == 12000000) && (baudrate == 115200)) {
 143                 port->osc_12m_sel = OSC_12M_SEL;  /* enable 6.5 * divisor */
 144                 return 1;                       /* return 1 for base divisor */
 145         }
 146         port->osc_12m_sel = 0;                  /* clear if previsouly set */
 147 #endif
 148
 149         return calc_divisor(port, clock, baudrate);
 150 }
 151
 152 static void NS16550_setbrg(NS16550_t com_port, int baud_divisor)
 153 {
 154         serial_out(UART_LCR_BKSE | UART_LCRVAL, &com_port->lcr);
 155         serial_out(baud_divisor & 0xff, &com_port->dll);
 156         serial_out((baud_divisor >> 8) & 0xff, &com_port->dlm);
 157         serial_out(UART_LCRVAL, &com_port->lcr);
 158 }
 159
 160 void NS16550_init(NS16550_t com_port, int baud_divisor)
 161 {
 162 #if (defined(CONFIG_SPL_BUILD) && \
 163                 (defined(CONFIG_OMAP34XX) || defined(CONFIG_OMAP44XX)))
 164         /*
 165          * On some OMAP3/OMAP4 devices when UART3 is configured for boot mode
 166          * before SPL starts only THRE bit is set. We have to empty the
 167          * transmitter before initialization starts.
 168          */
 169         if ((serial_in(&com_port->lsr) & (UART_LSR_TEMT | UART_LSR_THRE))
 170              == UART_LSR_THRE) {
 171                 if (baud_divisor != -1)
 172                         NS16550_setbrg(com_port, baud_divisor);
 173                 serial_out(0, &com_port->mdr1);
 174         }
 175 #endif
 176
 177         while (!(serial_in(&com_port->lsr) & UART_LSR_TEMT))
 178                 ;
 179
 180         serial_out(CONFIG_SYS_NS16550_IER, &com_port->ier);
 181 #if defined(CONFIG_OMAP) || defined(CONFIG_AM33XX) || \
 182                         defined(CONFIG_TI81XX) || defined(CONFIG_AM43XX)
 183         serial_out(0x7, &com_port->mdr1);       /* mode select reset TL16C750*/
 184 #endif
 185         serial_out(UART_MCRVAL, &com_port->mcr);
 186         serial_out(UART_FCRVAL, &com_port->fcr);
 187         if (baud_divisor != -1)
 188                 NS16550_setbrg(com_port, baud_divisor);
 189 #if defined(CONFIG_OMAP) || \
 190         defined(CONFIG_AM33XX) || defined(CONFIG_SOC_DA8XX) || \
 191         defined(CONFIG_TI81XX) || defined(CONFIG_AM43XX)
 192
 193         /* /16 is proper to hit 115200 with 48MHz */
 194         serial_out(0, &com_port->mdr1);
 195 #endif /* CONFIG_OMAP */
 196 #if defined(CONFIG_SOC_KEYSTONE)
 197         serial_out(UART_REG_VAL_PWREMU_MGMT_UART_ENABLE, &com_port->regC);
 198 #endif
 199 }
 200
 201 #ifndef CONFIG_NS16550_MIN_FUNCTIONS
 202 void NS16550_reinit(NS16550_t com_port, int baud_divisor)
 203 {
 204         serial_out(CONFIG_SYS_NS16550_IER, &com_port->ier);
 205         NS16550_setbrg(com_port, 0);
 206         serial_out(UART_MCRVAL, &com_port->mcr);
 207         serial_out(UART_FCRVAL, &com_port->fcr);
 208         NS16550_setbrg(com_port, baud_divisor);
 209 }
 210 #endif /* CONFIG_NS16550_MIN_FUNCTIONS */
 211
 212 void NS16550_putc(NS16550_t com_port, char c)
 213 {
 214         while ((serial_in(&com_port->lsr) & UART_LSR_THRE) == 0)
 215                 ;
 216         serial_out(c, &com_port->thr);
 217
 218         /*
 219          * Call watchdog_reset() upon newline. This is done here in putc
 220          * since the environment code uses a single puts() to print the complete
 221          * environment upon "printenv". So we can't put this watchdog call
 222          * in puts().
 223          */
 224         if (c == '\n')
 225                 WATCHDOG_RESET();
 226 }
 227
 228 #ifndef CONFIG_NS16550_MIN_FUNCTIONS
 229 char NS16550_getc(NS16550_t com_port)
 230 {
 231         while ((serial_in(&com_port->lsr) & UART_LSR_DR) == 0) {
 232 #if !defined(CONFIG_SPL_BUILD) && defined(CONFIG_USB_TTY)
 233                 extern void usbtty_poll(void);
 234                 usbtty_poll();
 235 #endif
 236                 WATCHDOG_RESET();
 237         }
 238         return serial_in(&com_port->rbr);
 239 }
 240
 241 int NS16550_tstc(NS16550_t com_port)
 242 {
 243         return (serial_in(&com_port->lsr) & UART_LSR_DR) != 0;
 244 }
 245
 246 #endif /* CONFIG_NS16550_MIN_FUNCTIONS */
 247
 248 #ifdef CONFIG_DEBUG_UART_NS16550
 249
 250 #include <debug_uart.h>
 251
 252 #define serial_dout(reg, value) \
 253         serial_out_shift((char *)com_port + \
 254                 ((char *)reg - (char *)com_port) * \
 255                         (1 << CONFIG_DEBUG_UART_SHIFT), \
 256                 CONFIG_DEBUG_UART_SHIFT, value)
 257 #define serial_din(reg) \
 258         serial_in_shift((char *)com_port + \
 259                 ((char *)reg - (char *)com_port) * \
 260                         (1 << CONFIG_DEBUG_UART_SHIFT), \
 261                 CONFIG_DEBUG_UART_SHIFT)
 262
 263 static inline void _debug_uart_init(void)
 264 {
 265         struct NS16550 *com_port = (struct NS16550 *)CONFIG_DEBUG_UART_BASE;
 266         int baud_divisor;
 267
 268         /*
 269          * We copy the code from above because it is already horribly messy.
 270          * Trying to refactor to nicely remove the duplication doesn't seem
 271          * feasible. The better fix is to move all users of this driver to
 272          * driver model.
 273          */
 274         baud_divisor = calc_divisor(com_port, CONFIG_DEBUG_UART_CLOCK,
 275                                     CONFIG_BAUDRATE);
 276         serial_dout(&com_port->ier, CONFIG_SYS_NS16550_IER);
 277         serial_dout(&com_port->mcr, UART_MCRVAL);
 278         serial_dout(&com_port->fcr, UART_FCRVAL);
 279
 280         serial_dout(&com_port->lcr, UART_LCR_BKSE | UART_LCRVAL);
 281         serial_dout(&com_port->dll, baud_divisor & 0xff);
 282         serial_dout(&com_port->dlm, (baud_divisor >> 8) & 0xff);
 283         serial_dout(&com_port->lcr, UART_LCRVAL);
 284 }
 285
 286 static inline void _debug_uart_putc(int ch)
 287 {
 288         struct NS16550 *com_port = (struct NS16550 *)CONFIG_DEBUG_UART_BASE;
 289
 290         while (!(serial_din(&com_port->lsr) & UART_LSR_THRE))
 291                 ;
 292         serial_dout(&com_port->thr, ch);
 293 }
 294
 295 DEBUG_UART_FUNCS
 296
 297 #endif
 298
 299 #ifdef CONFIG_DM_SERIAL
 300 static int ns16550_serial_putc(struct udevice *dev, const char ch)
 301 {
 302         struct NS16550 *const com_port = dev_get_priv(dev);
 303
 304         if (!(serial_in(&com_port->lsr) & UART_LSR_THRE))
 305                 return -EAGAIN;
 306         serial_out(ch, &com_port->thr);
 307
 308         /*
 309          * Call watchdog_reset() upon newline. This is done here in putc
 310          * since the environment code uses a single puts() to print the complete
 311          * environment upon "printenv". So we can't put this watchdog call
 312          * in puts().
 313          */
 314         if (ch == '\n')
 315                 WATCHDOG_RESET();
 316
 317         return 0;
 318 }
 319
 320 static int ns16550_serial_pending(struct udevice *dev, bool input)
 321 {
 322         struct NS16550 *const com_port = dev_get_priv(dev);
 323
 324         if (input)
 325                 return serial_in(&com_port->lsr) & UART_LSR_DR ? 1 : 0;
 326         else
 327                 return serial_in(&com_port->lsr) & UART_LSR_THRE ? 0 : 1;
 328 }
 329
 330 static int ns16550_serial_getc(struct udevice *dev)
 331 {
 332         struct NS16550 *const com_port = dev_get_priv(dev);
 333
 334         if (!(serial_in(&com_port->lsr) & UART_LSR_DR))
 335                 return -EAGAIN;
 336
 337         return serial_in(&com_port->rbr);
 338 }
 339
 340 static int ns16550_serial_setbrg(struct udevice *dev, int baudrate)
 341 {
 342         struct NS16550 *const com_port = dev_get_priv(dev);
 343         struct ns16550_platdata *plat = com_port->plat;
 344         int clock_divisor;
 345
 346         clock_divisor = ns16550_calc_divisor(com_port, plat->clock, baudrate);
 347
 348         NS16550_setbrg(com_port, clock_divisor);
 349
 350         return 0;
 351 }
 352
 353 int ns16550_serial_probe(struct udevice *dev)
 354 {
 355         struct NS16550 *const com_port = dev_get_priv(dev);
 356
 357         com_port->plat = dev_get_platdata(dev);
 358         NS16550_init(com_port, -1);
 359
 360         return 0;
 361 }
 362
 363 #if CONFIG_IS_ENABLED(OF_CONTROL)
 364 int ns16550_serial_ofdata_to_platdata(struct udevice *dev)
 365 {
 366         struct ns16550_platdata *plat = dev->platdata;
 367         fdt_addr_t addr;
 368
 369         /* try Processor Local Bus device first */
 370         addr = dev_get_addr(dev);
 371 #if defined(CONFIG_PCI) && defined(CONFIG_DM_PCI)
 372         if (addr == FDT_ADDR_T_NONE) {
 373                 /* then try pci device */
 374                 struct fdt_pci_addr pci_addr;
 375                 u32 bar;
 376                 int ret;
 377
 378                 /* we prefer to use a memory-mapped register */
 379                 ret = fdtdec_get_pci_addr(gd->fdt_blob, dev->of_offset,
 380                                           FDT_PCI_SPACE_MEM32, "reg",
 381                                           &pci_addr);
 382                 if (ret) {
 383                         /* try if there is any i/o-mapped register */
 384                         ret = fdtdec_get_pci_addr(gd->fdt_blob,
 385                                                   dev->of_offset,
 386                                                   FDT_PCI_SPACE_IO,
 387                                                   "reg", &pci_addr);
 388                         if (ret)
 389                                 return ret;
 390                 }
 391
 392                 ret = fdtdec_get_pci_bar32(dev, &pci_addr, &bar);
 393                 if (ret)
 394                         return ret;
 395
 396                 addr = bar;
 397         }
 398 #endif
 399
 400         if (addr == FDT_ADDR_T_NONE)
 401                 return -EINVAL;
 402
 403         plat->base = addr;
 404         plat->reg_shift = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
 405                                          "reg-shift", 0);
 406         plat->clock = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
 407                                      "clock-frequency",
 408                                      CONFIG_SYS_NS16550_CLK);
 409         if (!plat->clock) {
 410                 debug("ns16550 clock not defined\n");
 411                 return -EINVAL;
 412         }
 413
 414         return 0;
 415 }
 416 #endif
 417
 418 const struct dm_serial_ops ns16550_serial_ops = {
 419         .putc = ns16550_serial_putc,
 420         .pending = ns16550_serial_pending,
 421         .getc = ns16550_serial_getc,
 422         .setbrg = ns16550_serial_setbrg,
 423 };
 424
 425 #if CONFIG_IS_ENABLED(OF_CONTROL)
 426 /*
 427  * Please consider existing compatible strings before adding a new
 428  * one to keep this table compact. Or you may add a generic "ns16550"
 429  * compatible string to your dts.
 430  */
 431 static const struct udevice_id ns16550_serial_ids[] = {
 432         { .compatible = "ns16550" },
 433         { .compatible = "ns16550a" },
 434         { .compatible = "nvidia,tegra20-uart" },
 435         { .compatible = "snps,dw-apb-uart" },
 436         { .compatible = "ti,omap2-uart" },
 437         { .compatible = "ti,omap3-uart" },
 438         { .compatible = "ti,omap4-uart" },
 439         { .compatible = "ti,am3352-uart" },
 440         { .compatible = "ti,am4372-uart" },
 441         { .compatible = "ti,dra742-uart" },
 442         {}
 443 };
 444 #endif
 445
 446 #if CONFIG_IS_ENABLED(SERIAL_PRESENT)
 447 U_BOOT_DRIVER(ns16550_serial) = {
 448         .name   = "ns16550_serial",
 449         .id     = UCLASS_SERIAL,
 450 #if CONFIG_IS_ENABLED(OF_CONTROL)
 451         .of_match = ns16550_serial_ids,
 452         .ofdata_to_platdata = ns16550_serial_ofdata_to_platdata,
 453         .platdata_auto_alloc_size = sizeof(struct ns16550_platdata),
 454 #endif
 455         .priv_auto_alloc_size = sizeof(struct NS16550),
 456         .probe = ns16550_serial_probe,
 457         .ops    = &ns16550_serial_ops,
 458         .flags  = DM_FLAG_PRE_RELOC,
 459 };
 460 #endif
 461 #endif /* CONFIG_DM_SERIAL */