arch/arm/mach-omap2/serial.c

   1 /*
   2  * arch/arm/mach-omap2/serial.c
   3  *
   4  * OMAP2 serial support.
   5  *
   6  * Copyright (C) 2005-2008 Nokia Corporation
   7  * Author: Paul Mundt <paul.mundt@nokia.com>
   8  *
   9  * Major rework for PM support by Kevin Hilman
  10  *
  11  * Based off of arch/arm/mach-omap/omap1/serial.c
  12  *
  13  * This file is subject to the terms and conditions of the GNU General Public
  14  * License. See the file "COPYING" in the main directory of this archive
  15  * for more details.
  16  */
  17 #include <linux/kernel.h>
  18 #include <linux/init.h>
  19 #include <linux/serial_8250.h>
  20 #include <linux/serial_reg.h>
  21 #include <linux/clk.h>
  22 #include <linux/io.h>
  23
  24 #include <mach/common.h>
  25 #include <mach/board.h>
  26 #include <mach/clock.h>
  27 #include <mach/control.h>
  28
  29 #include "prm.h"
  30 #include "pm.h"
  31 #include "prm-regbits-34xx.h"
  32
  33 #define UART_OMAP_WER           0x17    /* Wake-up enable register */
  34
  35 #define DEFAULT_TIMEOUT (5 * HZ)
  36
  37 struct omap_uart_state {
  38         int num;
  39         int can_sleep;
  40         struct timer_list timer;
  41         u32 timeout;
  42
  43         void __iomem *wk_st;
  44         void __iomem *wk_en;
  45         u32 wk_mask;
  46         u32 padconf;
  47
  48         struct clk *ick;
  49         struct clk *fck;
  50         int clocked;
  51
  52         struct plat_serial8250_port *p;
  53         struct list_head node;
  54
  55 #if defined(CONFIG_ARCH_OMAP3) && defined(CONFIG_PM)
  56         int context_valid;
  57
  58         /* Registers to be saved/restored for OFF-mode */
  59         u16 dll;
  60         u16 dlh;
  61         u16 ier;
  62         u16 sysc;
  63         u16 scr;
  64         u16 wer;
  65 #endif
  66 };
  67
  68 static struct omap_uart_state omap_uart[OMAP_MAX_NR_PORTS];
  69 static LIST_HEAD(uart_list);
  70
  71 static struct plat_serial8250_port serial_platform_data[] = {
  72         {
  73                 .membase        = IO_ADDRESS(OMAP_UART1_BASE),
  74                 .mapbase        = OMAP_UART1_BASE,
  75                 .irq            = 72,
  76                 .flags          = UPF_BOOT_AUTOCONF,
  77                 .iotype         = UPIO_MEM,
  78                 .regshift       = 2,
  79                 .uartclk        = OMAP24XX_BASE_BAUD * 16,
  80         }, {
  81                 .membase        = IO_ADDRESS(OMAP_UART2_BASE),
  82                 .mapbase        = OMAP_UART2_BASE,
  83                 .irq            = 73,
  84                 .flags          = UPF_BOOT_AUTOCONF,
  85                 .iotype         = UPIO_MEM,
  86                 .regshift       = 2,
  87                 .uartclk        = OMAP24XX_BASE_BAUD * 16,
  88         }, {
  89                 .membase        = IO_ADDRESS(OMAP_UART3_BASE),
  90                 .mapbase        = OMAP_UART3_BASE,
  91                 .irq            = 74,
  92                 .flags          = UPF_BOOT_AUTOCONF,
  93                 .iotype         = UPIO_MEM,
  94                 .regshift       = 2,
  95                 .uartclk        = OMAP24XX_BASE_BAUD * 16,
  96         }, {
  97                 .flags          = 0
  98         }
  99 };
 100
 101 static inline unsigned int serial_read_reg(struct plat_serial8250_port *up,
 102                                            int offset)
 103 {
 104         offset <<= up->regshift;
 105         return (unsigned int)__raw_readb(up->membase + offset);
 106 }
 107
 108 static inline void serial_write_reg(struct plat_serial8250_port *p, int offset,
 109                                     int value)
 110 {
 111         offset <<= p->regshift;
 112         __raw_writeb(value, p->membase + offset);
 113 }
 114
 115 /*
 116  * Internal UARTs need to be initialized for the 8250 autoconfig to work
 117  * properly. Note that the TX watermark initialization may not be needed
 118  * once the 8250.c watermark handling code is merged.
 119  */
 120 static inline void __init omap_uart_reset(struct omap_uart_state *uart)
 121 {
 122         struct plat_serial8250_port *p = uart->p;
 123
 124         serial_write_reg(p, UART_OMAP_MDR1, 0x07);
 125         serial_write_reg(p, UART_OMAP_SCR, 0x08);
 126         serial_write_reg(p, UART_OMAP_MDR1, 0x00);
 127         serial_write_reg(p, UART_OMAP_SYSC, (0x02 << 3) | (1 << 2) | (1 << 0));
 128 }
 129
 130 #if defined(CONFIG_PM) && defined(CONFIG_ARCH_OMAP3)
 131
 132 static int enable_off_mode; /* to be removed by full off-mode patches */
 133
 134 static void omap_uart_save_context(struct omap_uart_state *uart)
 135 {
 136         u16 lcr = 0;
 137         struct plat_serial8250_port *p = uart->p;
 138
 139         if (!enable_off_mode)
 140                 return;
 141
 142         lcr = serial_read_reg(p, UART_LCR);
 143         serial_write_reg(p, UART_LCR, 0xBF);
 144         uart->dll = serial_read_reg(p, UART_DLL);
 145         uart->dlh = serial_read_reg(p, UART_DLM);
 146         serial_write_reg(p, UART_LCR, lcr);
 147         uart->ier = serial_read_reg(p, UART_IER);
 148         uart->sysc = serial_read_reg(p, UART_OMAP_SYSC);
 149         uart->scr = serial_read_reg(p, UART_OMAP_SCR);
 150         uart->wer = serial_read_reg(p, UART_OMAP_WER);
 151
 152         uart->context_valid = 1;
 153 }
 154
 155 static void omap_uart_restore_context(struct omap_uart_state *uart)
 156 {
 157         u16 efr = 0;
 158         struct plat_serial8250_port *p = uart->p;
 159
 160         if (!enable_off_mode)
 161                 return;
 162
 163         if (!uart->context_valid)
 164                 return;
 165
 166         uart->context_valid = 0;
 167
 168         serial_write_reg(p, UART_OMAP_MDR1, 0x7);
 169         serial_write_reg(p, UART_LCR, 0xBF); /* Config B mode */
 170         efr = serial_read_reg(p, UART_EFR);
 171         serial_write_reg(p, UART_EFR, UART_EFR_ECB);
 172         serial_write_reg(p, UART_LCR, 0x0); /* Operational mode */
 173         serial_write_reg(p, UART_IER, 0x0);
 174         serial_write_reg(p, UART_LCR, 0xBF); /* Config B mode */
 175         serial_write_reg(p, UART_DLL, uart->dll);
 176         serial_write_reg(p, UART_DLM, uart->dlh);
 177         serial_write_reg(p, UART_LCR, 0x0); /* Operational mode */
 178         serial_write_reg(p, UART_IER, uart->ier);
 179         serial_write_reg(p, UART_FCR, 0xA1);
 180         serial_write_reg(p, UART_LCR, 0xBF); /* Config B mode */
 181         serial_write_reg(p, UART_EFR, efr);
 182         serial_write_reg(p, UART_LCR, UART_LCR_WLEN8);
 183         serial_write_reg(p, UART_OMAP_SCR, uart->scr);
 184         serial_write_reg(p, UART_OMAP_WER, uart->wer);
 185         serial_write_reg(p, UART_OMAP_SYSC, uart->sysc);
 186         serial_write_reg(p, UART_OMAP_MDR1, 0x00); /* UART 16x mode */
 187 }
 188 #else
 189 static inline void omap_uart_save_context(struct omap_uart_state *uart) {}
 190 static inline void omap_uart_restore_context(struct omap_uart_state *uart) {}
 191 #endif /* CONFIG_PM && CONFIG_ARCH_OMAP3 */
 192
 193 static inline void omap_uart_enable_clocks(struct omap_uart_state *uart)
 194 {
 195         if (uart->clocked)
 196                 return;
 197
 198         clk_enable(uart->ick);
 199         clk_enable(uart->fck);
 200         uart->clocked = 1;
 201         omap_uart_restore_context(uart);
 202 }
 203
 204 #ifdef CONFIG_PM
 205
 206 static inline void omap_uart_disable_clocks(struct omap_uart_state *uart)
 207 {
 208         if (!uart->clocked)
 209                 return;
 210
 211         omap_uart_save_context(uart);
 212         uart->clocked = 0;
 213         clk_disable(uart->ick);
 214         clk_disable(uart->fck);
 215 }
 216
 217 static void omap_uart_smart_idle_enable(struct omap_uart_state *uart,
 218                                           int enable)
 219 {
 220         struct plat_serial8250_port *p = uart->p;
 221         u16 sysc;
 222
 223         sysc = serial_read_reg(p, UART_OMAP_SYSC) & 0x7;
 224         if (enable)
 225                 sysc |= 0x2 << 3;
 226         else
 227                 sysc |= 0x1 << 3;
 228
 229         serial_write_reg(p, UART_OMAP_SYSC, sysc);
 230 }
 231
 232 static void omap_uart_block_sleep(struct omap_uart_state *uart)
 233 {
 234         omap_uart_enable_clocks(uart);
 235
 236         omap_uart_smart_idle_enable(uart, 0);
 237         uart->can_sleep = 0;
 238         if (uart->timeout)
 239                 mod_timer(&uart->timer, jiffies + uart->timeout);
 240         else
 241                 del_timer(&uart->timer);
 242 }
 243
 244 static void omap_uart_allow_sleep(struct omap_uart_state *uart)
 245 {
 246         if (!uart->clocked)
 247                 return;
 248
 249         omap_uart_smart_idle_enable(uart, 1);
 250         uart->can_sleep = 1;
 251         del_timer(&uart->timer);
 252 }
 253
 254 static void omap_uart_idle_timer(unsigned long data)
 255 {
 256         struct omap_uart_state *uart = (struct omap_uart_state *)data;
 257
 258         omap_uart_allow_sleep(uart);
 259 }
 260
 261 void omap_uart_prepare_idle(int num)
 262 {
 263         struct omap_uart_state *uart;
 264
 265         list_for_each_entry(uart, &uart_list, node) {
 266                 if (num == uart->num && uart->can_sleep) {
 267                         omap_uart_disable_clocks(uart);
 268                         return;
 269                 }
 270         }
 271 }
 272
 273 void omap_uart_resume_idle(int num)
 274 {
 275         struct omap_uart_state *uart;
 276
 277         list_for_each_entry(uart, &uart_list, node) {
 278                 if (num == uart->num) {
 279                         omap_uart_enable_clocks(uart);
 280
 281                         /* Check for IO pad wakeup */
 282                         if (cpu_is_omap34xx() && uart->padconf) {
 283                                 u16 p = omap_ctrl_readw(uart->padconf);
 284
 285                                 if (p & OMAP3_PADCONF_WAKEUPEVENT0)
 286                                         omap_uart_block_sleep(uart);
 287                         }
 288
 289                         /* Check for normal UART wakeup */
 290                         if (__raw_readl(uart->wk_st) & uart->wk_mask)
 291                                 omap_uart_block_sleep(uart);
 292
 293                         return;
 294                 }
 295         }
 296 }
 297
 298 void omap_uart_prepare_suspend(void)
 299 {
 300         struct omap_uart_state *uart;
 301
 302         list_for_each_entry(uart, &uart_list, node) {
 303                 omap_uart_allow_sleep(uart);
 304         }
 305 }
 306
 307 int omap_uart_can_sleep(void)
 308 {
 309         struct omap_uart_state *uart;
 310         int can_sleep = 1;
 311
 312         list_for_each_entry(uart, &uart_list, node) {
 313                 if (!uart->clocked)
 314                         continue;
 315
 316                 if (!uart->can_sleep) {
 317                         can_sleep = 0;
 318                         continue;
 319                 }
 320
 321                 /* This UART can now safely sleep. */
 322                 omap_uart_allow_sleep(uart);
 323         }
 324
 325         return can_sleep;
 326 }
 327
 328 /**
 329  * omap_uart_interrupt()
 330  *
 331  * This handler is used only to detect that *any* UART interrupt has
 332  * occurred.  It does _nothing_ to handle the interrupt.  Rather,
 333  * any UART interrupt will trigger the inactivity timer so the
 334  * UART will not idle or sleep for its timeout period.
 335  *
 336  **/
 337 static irqreturn_t omap_uart_interrupt(int irq, void *dev_id)
 338 {
 339         struct omap_uart_state *uart = dev_id;
 340
 341         omap_uart_block_sleep(uart);
 342
 343         return IRQ_NONE;
 344 }
 345
 346 static u32 sleep_timeout = DEFAULT_TIMEOUT;
 347
 348 static void omap_uart_idle_init(struct omap_uart_state *uart)
 349 {
 350         u32 v;
 351         struct plat_serial8250_port *p = uart->p;
 352         int ret;
 353
 354         uart->can_sleep = 0;
 355         uart->timeout = sleep_timeout;
 356         setup_timer(&uart->timer, omap_uart_idle_timer,
 357                     (unsigned long) uart);
 358         mod_timer(&uart->timer, jiffies + uart->timeout);
 359         omap_uart_smart_idle_enable(uart, 0);
 360
 361         if (cpu_is_omap34xx()) {
 362                 u32 mod = (uart->num == 2) ? OMAP3430_PER_MOD : CORE_MOD;
 363                 u32 wk_mask = 0;
 364                 u32 padconf = 0;
 365
 366                 uart->wk_en = OMAP34XX_PRM_REGADDR(mod, PM_WKEN1);
 367                 uart->wk_st = OMAP34XX_PRM_REGADDR(mod, PM_WKST1);
 368                 switch (uart->num) {
 369                 case 0:
 370                         wk_mask = OMAP3430_ST_UART1_MASK;
 371                         padconf = 0x182;
 372                         break;
 373                 case 1:
 374                         wk_mask = OMAP3430_ST_UART2_MASK;
 375                         padconf = 0x17a;
 376                         break;
 377                 case 2:
 378                         wk_mask = OMAP3430_ST_UART3_MASK;
 379                         padconf = 0x19e;
 380                         break;
 381                 }
 382                 uart->wk_mask = wk_mask;
 383                 uart->padconf = padconf;
 384         } else if (cpu_is_omap24xx()) {
 385                 u32 wk_mask = 0;
 386
 387                 if (cpu_is_omap2430()) {
 388                         uart->wk_en = OMAP2430_PRM_REGADDR(CORE_MOD, PM_WKEN1);
 389                         uart->wk_st = OMAP2430_PRM_REGADDR(CORE_MOD, PM_WKST1);
 390                 } else if (cpu_is_omap2420()) {
 391                         uart->wk_en = OMAP2420_PRM_REGADDR(CORE_MOD, PM_WKEN1);
 392                         uart->wk_st = OMAP2420_PRM_REGADDR(CORE_MOD, PM_WKST1);
 393                 }
 394                 switch (uart->num) {
 395                 case 0:
 396                         wk_mask = OMAP24XX_ST_UART1_MASK;
 397                         break;
 398                 case 1:
 399                         wk_mask = OMAP24XX_ST_UART2_MASK;
 400                         break;
 401                 case 2:
 402                         wk_mask = OMAP24XX_ST_UART3_MASK;
 403                         break;
 404                 }
 405                 uart->wk_mask = wk_mask;
 406         } else {
 407                 uart->wk_en = 0;
 408                 uart->wk_st = 0;
 409                 uart->wk_mask = 0;
 410                 uart->padconf = 0;
 411         }
 412
 413         /* Set wake-enable bit */
 414         if (uart->wk_en && uart->wk_mask) {
 415                 v = __raw_readl(uart->wk_en);
 416                 v |= uart->wk_mask;
 417                 __raw_writel(v, uart->wk_en);
 418         }
 419
 420         /* Ensure IOPAD wake-enables are set */
 421         if (cpu_is_omap34xx() && uart->padconf) {
 422                 u16 v;
 423
 424                 v = omap_ctrl_readw(uart->padconf);
 425                 v |= OMAP3_PADCONF_WAKEUPENABLE0;
 426                 omap_ctrl_writew(v, uart->padconf);
 427         }
 428
 429         p->flags |= UPF_SHARE_IRQ;
 430         ret = request_irq(p->irq, omap_uart_interrupt, IRQF_SHARED,
 431                           "serial idle", (void *)uart);
 432         WARN_ON(ret);
 433 }
 434
 435 static ssize_t sleep_timeout_show(struct kobject *kobj,
 436                                   struct kobj_attribute *attr,
 437                                   char *buf)
 438 {
 439         return sprintf(buf, "%u\n", sleep_timeout / HZ);
 440 }
 441
 442 static ssize_t sleep_timeout_store(struct kobject *kobj,
 443                                    struct kobj_attribute *attr,
 444                                    const char *buf, size_t n)
 445 {
 446         struct omap_uart_state *uart;
 447         unsigned int value;
 448
 449         if (sscanf(buf, "%u", &value) != 1) {
 450                 printk(KERN_ERR "sleep_timeout_store: Invalid value\n");
 451                 return -EINVAL;
 452         }
 453         sleep_timeout = value * HZ;
 454         list_for_each_entry(uart, &uart_list, node) {
 455                 uart->timeout = sleep_timeout;
 456                 if (uart->timeout)
 457                         mod_timer(&uart->timer, jiffies + uart->timeout);
 458                 else
 459                         /* A zero value means disable timeout feature */
 460                         omap_uart_block_sleep(uart);
 461         }
 462         return n;
 463 }
 464
 465 static struct kobj_attribute sleep_timeout_attr =
 466         __ATTR(sleep_timeout, 0644, sleep_timeout_show, sleep_timeout_store);
 467
 468 #else
 469 static inline void omap_uart_idle_init(struct omap_uart_state *uart) {}
 470 #endif /* CONFIG_PM */
 471
 472 static struct platform_device serial_device = {
 473         .name                   = "serial8250",
 474         .id                     = PLAT8250_DEV_PLATFORM,
 475         .dev                    = {
 476                 .platform_data  = serial_platform_data,
 477         },
 478 };
 479
 480 void __init omap_serial_init(void)
 481 {
 482         int i, err;
 483         const struct omap_uart_config *info;
 484         char name[16];
 485
 486         /*
 487          * Make sure the serial ports are muxed on at this point.
 488          * You have to mux them off in device drivers later on
 489          * if not needed.
 490          */
 491
 492         info = omap_get_config(OMAP_TAG_UART, struct omap_uart_config);
 493
 494         if (info == NULL)
 495                 return;
 496
 497         for (i = 0; i < OMAP_MAX_NR_PORTS; i++) {
 498                 struct plat_serial8250_port *p = serial_platform_data + i;
 499                 struct omap_uart_state *uart = &omap_uart[i];
 500
 501                 if (!(info->enabled_uarts & (1 << i))) {
 502                         p->membase = NULL;
 503                         p->mapbase = 0;
 504                         continue;
 505                 }
 506
 507                 sprintf(name, "uart%d_ick", i+1);
 508                 uart->ick = clk_get(NULL, name);
 509                 if (IS_ERR(uart->ick)) {
 510                         printk(KERN_ERR "Could not get uart%d_ick\n", i+1);
 511                         uart->ick = NULL;
 512                 }
 513
 514                 sprintf(name, "uart%d_fck", i+1);
 515                 uart->fck = clk_get(NULL, name);
 516                 if (IS_ERR(uart->fck)) {
 517                         printk(KERN_ERR "Could not get uart%d_fck\n", i+1);
 518                         uart->fck = NULL;
 519                 }
 520
 521                 if (!uart->ick || !uart->fck)
 522                         continue;
 523
 524                 uart->num = i;
 525                 p->private_data = uart;
 526                 uart->p = p;
 527                 list_add(&uart->node, &uart_list);
 528
 529                 omap_uart_enable_clocks(uart);
 530                 omap_uart_reset(uart);
 531                 omap_uart_idle_init(uart);
 532         }
 533
 534         err = platform_device_register(&serial_device);
 535
 536 #ifdef CONFIG_PM
 537         if (!err)
 538                 err = sysfs_create_file(&serial_device.dev.kobj,
 539                                         &sleep_timeout_attr.attr);
 540 #endif
 541
 542 }
 543