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  * Copyright (C) 2009 Texas Instruments
  14  * Added OMAP4 support - Santosh Shilimkar <santosh.shilimkar@ti.com
  15  *
  16  * This file is subject to the terms and conditions of the GNU General Public
  17  * License. See the file "COPYING" in the main directory of this archive
  18  * for more details.
  19  */
  20 #include <linux/kernel.h>
  21 #include <linux/init.h>
  22 #include <linux/clk.h>
  23 #include <linux/io.h>
  24 #include <linux/delay.h>
  25 #include <linux/platform_device.h>
  26 #include <linux/slab.h>
  27 #include <linux/pm_runtime.h>
  28 #include <linux/console.h>
  29
  30 #include <plat/omap-serial.h>
  31 #include "common.h"
  32 #include <plat/dma.h>
  33 #include <plat/omap_hwmod.h>
  34 #include <plat/omap_device.h>
  35 #include <plat/omap-pm.h>
  36
  37 #include "prm2xxx_3xxx.h"
  38 #include "pm.h"
  39 #include "cm2xxx_3xxx.h"
  40 #include "prm-regbits-34xx.h"
  41 #include "control.h"
  42 #include "mux.h"
  43
  44 /*
  45  * NOTE: By default the serial auto_suspend timeout is disabled as it causes
  46  * lost characters over the serial ports. This means that the UART clocks will
  47  * stay on until power/autosuspend_delay is set for the uart from sysfs.
  48  * This also causes that any deeper omap sleep states are blocked.
  49  */
  50 #define DEFAULT_AUTOSUSPEND_DELAY       -1
  51
  52 #define MAX_UART_HWMOD_NAME_LEN         16
  53
  54 struct omap_uart_state {
  55         int num;
  56
  57         struct list_head node;
  58         struct omap_hwmod *oh;
  59         struct omap_device_pad default_omap_uart_pads[2];
  60 };
  61
  62 static LIST_HEAD(uart_list);
  63 static u8 num_uarts;
  64 static u8 console_uart_id = -1;
  65 static u8 no_console_suspend;
  66 static u8 uart_debug;
  67
  68 #define DEFAULT_RXDMA_POLLRATE          1       /* RX DMA polling rate (us) */
  69 #define DEFAULT_RXDMA_BUFSIZE           4096    /* RX DMA buffer size */
  70 #define DEFAULT_RXDMA_TIMEOUT           (3 * HZ)/* RX DMA timeout (jiffies) */
  71
  72 static struct omap_uart_port_info omap_serial_default_info[] __initdata = {
  73         {
  74                 .dma_enabled    = false,
  75                 .dma_rx_buf_size = DEFAULT_RXDMA_BUFSIZE,
  76                 .dma_rx_poll_rate = DEFAULT_RXDMA_POLLRATE,
  77                 .dma_rx_timeout = DEFAULT_RXDMA_TIMEOUT,
  78                 .autosuspend_timeout = DEFAULT_AUTOSUSPEND_DELAY,
  79         },
  80 };
  81
  82 #ifdef CONFIG_PM
  83 static void omap_uart_enable_wakeup(struct platform_device *pdev, bool enable)
  84 {
  85         struct omap_device *od = to_omap_device(pdev);
  86
  87         if (!od)
  88                 return;
  89
  90         if (enable)
  91                 omap_hwmod_enable_wakeup(od->hwmods[0]);
  92         else
  93                 omap_hwmod_disable_wakeup(od->hwmods[0]);
  94 }
  95
  96 /*
  97  * Errata i291: [UART]:Cannot Acknowledge Idle Requests
  98  * in Smartidle Mode When Configured for DMA Operations.
  99  * WA: configure uart in force idle mode.
 100  */
 101 static void omap_uart_set_noidle(struct platform_device *pdev)
 102 {
 103         struct omap_device *od = to_omap_device(pdev);
 104
 105         omap_hwmod_set_slave_idlemode(od->hwmods[0], HWMOD_IDLEMODE_NO);
 106 }
 107
 108 static void omap_uart_set_smartidle(struct platform_device *pdev)
 109 {
 110         struct omap_device *od = to_omap_device(pdev);
 111         u8 idlemode;
 112
 113         if (od->hwmods[0]->class->sysc->idlemodes & SIDLE_SMART_WKUP)
 114                 idlemode = HWMOD_IDLEMODE_SMART_WKUP;
 115         else
 116                 idlemode = HWMOD_IDLEMODE_SMART;
 117
 118         omap_hwmod_set_slave_idlemode(od->hwmods[0], idlemode);
 119 }
 120
 121 #else
 122 static void omap_uart_enable_wakeup(struct platform_device *pdev, bool enable)
 123 {}
 124 static void omap_uart_set_noidle(struct platform_device *pdev) {}
 125 static void omap_uart_set_smartidle(struct platform_device *pdev) {}
 126 #endif /* CONFIG_PM */
 127
 128 #ifdef CONFIG_OMAP_MUX
 129
 130 #define OMAP_UART_DEFAULT_PAD_NAME_LEN  28
 131 static char rx_pad_name[OMAP_UART_DEFAULT_PAD_NAME_LEN],
 132                 tx_pad_name[OMAP_UART_DEFAULT_PAD_NAME_LEN] __initdata;
 133
 134 static void  __init
 135 omap_serial_fill_uart_tx_rx_pads(struct omap_board_data *bdata,
 136                                 struct omap_uart_state *uart)
 137 {
 138         uart->default_omap_uart_pads[0].name = rx_pad_name;
 139         uart->default_omap_uart_pads[0].flags = OMAP_DEVICE_PAD_REMUX |
 140                                                         OMAP_DEVICE_PAD_WAKEUP;
 141         uart->default_omap_uart_pads[0].enable = OMAP_PIN_INPUT |
 142                                                         OMAP_MUX_MODE0;
 143         uart->default_omap_uart_pads[0].idle = OMAP_PIN_INPUT | OMAP_MUX_MODE0;
 144         uart->default_omap_uart_pads[1].name = tx_pad_name;
 145         uart->default_omap_uart_pads[1].enable = OMAP_PIN_OUTPUT |
 146                                                         OMAP_MUX_MODE0;
 147         bdata->pads = uart->default_omap_uart_pads;
 148         bdata->pads_cnt = ARRAY_SIZE(uart->default_omap_uart_pads);
 149 }
 150
 151 static void  __init omap_serial_check_wakeup(struct omap_board_data *bdata,
 152                                                 struct omap_uart_state *uart)
 153 {
 154         struct omap_mux_partition *tx_partition = NULL, *rx_partition = NULL;
 155         struct omap_mux *rx_mux = NULL, *tx_mux = NULL;
 156         char *rx_fmt, *tx_fmt;
 157         int uart_nr = bdata->id + 1;
 158
 159         if (bdata->id != 2) {
 160                 rx_fmt = "uart%d_rx.uart%d_rx";
 161                 tx_fmt = "uart%d_tx.uart%d_tx";
 162         } else {
 163                 rx_fmt = "uart%d_rx_irrx.uart%d_rx_irrx";
 164                 tx_fmt = "uart%d_tx_irtx.uart%d_tx_irtx";
 165         }
 166
 167         snprintf(rx_pad_name, OMAP_UART_DEFAULT_PAD_NAME_LEN, rx_fmt,
 168                         uart_nr, uart_nr);
 169         snprintf(tx_pad_name, OMAP_UART_DEFAULT_PAD_NAME_LEN, tx_fmt,
 170                         uart_nr, uart_nr);
 171
 172         if (omap_mux_get_by_name(rx_pad_name, &rx_partition, &rx_mux) >= 0 &&
 173                         omap_mux_get_by_name
 174                                 (tx_pad_name, &tx_partition, &tx_mux) >= 0) {
 175                 u16 tx_mode, rx_mode;
 176
 177                 tx_mode = omap_mux_read(tx_partition, tx_mux->reg_offset);
 178                 rx_mode = omap_mux_read(rx_partition, rx_mux->reg_offset);
 179
 180                 /*
 181                  * Check if uart is used in default tx/rx mode i.e. in mux mode0
 182                  * if yes then configure rx pin for wake up capability
 183                  */
 184                 if (OMAP_MODE_UART(rx_mode) && OMAP_MODE_UART(tx_mode))
 185                         omap_serial_fill_uart_tx_rx_pads(bdata, uart);
 186         }
 187 }
 188 #else
 189 static void __init omap_serial_check_wakeup(struct omap_board_data *bdata,
 190                 struct omap_uart_state *uart)
 191 {
 192 }
 193 #endif
 194
 195 static char *cmdline_find_option(char *str)
 196 {
 197         extern char *saved_command_line;
 198
 199         return strstr(saved_command_line, str);
 200 }
 201
 202 static int __init omap_serial_early_init(void)
 203 {
 204         do {
 205                 char oh_name[MAX_UART_HWMOD_NAME_LEN];
 206                 struct omap_hwmod *oh;
 207                 struct omap_uart_state *uart;
 208                 char uart_name[MAX_UART_HWMOD_NAME_LEN];
 209
 210                 snprintf(oh_name, MAX_UART_HWMOD_NAME_LEN,
 211                          "uart%d", num_uarts + 1);
 212                 oh = omap_hwmod_lookup(oh_name);
 213                 if (!oh)
 214                         break;
 215
 216                 uart = kzalloc(sizeof(struct omap_uart_state), GFP_KERNEL);
 217                 if (WARN_ON(!uart))
 218                         return -ENODEV;
 219
 220                 uart->oh = oh;
 221                 uart->num = num_uarts++;
 222                 list_add_tail(&uart->node, &uart_list);
 223                 snprintf(uart_name, MAX_UART_HWMOD_NAME_LEN,
 224                                 "%s%d", OMAP_SERIAL_NAME, uart->num);
 225
 226                 if (cmdline_find_option(uart_name)) {
 227                         console_uart_id = uart->num;
 228
 229                         if (console_loglevel >= 10) {
 230                                 uart_debug = true;
 231                                 pr_info("%s used as console in debug mode"
 232                                                 " uart%d clocks will not be"
 233                                                 " gated", uart_name, uart->num);
 234                         }
 235
 236                         if (cmdline_find_option("no_console_suspend"))
 237                                 no_console_suspend = true;
 238
 239                         /*
 240                          * omap-uart can be used for earlyprintk logs
 241                          * So if omap-uart is used as console then prevent
 242                          * uart reset and idle to get logs from omap-uart
 243                          * until uart console driver is available to take
 244                          * care for console messages.
 245                          * Idling or resetting omap-uart while printing logs
 246                          * early boot logs can stall the boot-up.
 247                          */
 248                         oh->flags |= HWMOD_INIT_NO_IDLE | HWMOD_INIT_NO_RESET;
 249                 }
 250         } while (1);
 251
 252         return 0;
 253 }
 254 core_initcall(omap_serial_early_init);
 255
 256 /**
 257  * omap_serial_init_port() - initialize single serial port
 258  * @bdata: port specific board data pointer
 259  * @info: platform specific data pointer
 260  *
 261  * This function initialies serial driver for given port only.
 262  * Platforms can call this function instead of omap_serial_init()
 263  * if they don't plan to use all available UARTs as serial ports.
 264  *
 265  * Don't mix calls to omap_serial_init_port() and omap_serial_init(),
 266  * use only one of the two.
 267  */
 268 void __init omap_serial_init_port(struct omap_board_data *bdata,
 269                         struct omap_uart_port_info *info)
 270 {
 271         struct omap_uart_state *uart;
 272         struct omap_hwmod *oh;
 273         struct platform_device *pdev;
 274         void *pdata = NULL;
 275         u32 pdata_size = 0;
 276         char *name;
 277         struct omap_uart_port_info omap_up;
 278
 279         if (WARN_ON(!bdata))
 280                 return;
 281         if (WARN_ON(bdata->id < 0))
 282                 return;
 283         if (WARN_ON(bdata->id >= num_uarts))
 284                 return;
 285
 286         list_for_each_entry(uart, &uart_list, node)
 287                 if (bdata->id == uart->num)
 288                         break;
 289         if (!info)
 290                 info = omap_serial_default_info;
 291
 292         oh = uart->oh;
 293         name = DRIVER_NAME;
 294
 295         omap_up.dma_enabled = info->dma_enabled;
 296         omap_up.uartclk = OMAP24XX_BASE_BAUD * 16;
 297         omap_up.flags = UPF_BOOT_AUTOCONF;
 298         omap_up.get_context_loss_count = omap_pm_get_dev_context_loss_count;
 299         omap_up.set_forceidle = omap_uart_set_smartidle;
 300         omap_up.set_noidle = omap_uart_set_noidle;
 301         omap_up.enable_wakeup = omap_uart_enable_wakeup;
 302         omap_up.dma_rx_buf_size = info->dma_rx_buf_size;
 303         omap_up.dma_rx_timeout = info->dma_rx_timeout;
 304         omap_up.dma_rx_poll_rate = info->dma_rx_poll_rate;
 305         omap_up.autosuspend_timeout = info->autosuspend_timeout;
 306
 307         pdata = &omap_up;
 308         pdata_size = sizeof(struct omap_uart_port_info);
 309
 310         if (WARN_ON(!oh))
 311                 return;
 312
 313         pdev = omap_device_build(name, uart->num, oh, pdata, pdata_size,
 314                                  NULL, 0, false);
 315         WARN(IS_ERR(pdev), "Could not build omap_device for %s: %s.\n",
 316              name, oh->name);
 317
 318         if ((console_uart_id == bdata->id) && no_console_suspend)
 319                 omap_device_disable_idle_on_suspend(pdev);
 320
 321         oh->mux = omap_hwmod_mux_init(bdata->pads, bdata->pads_cnt);
 322
 323         oh->dev_attr = uart;
 324
 325         if (((cpu_is_omap34xx() || cpu_is_omap44xx()) && bdata->pads)
 326                         && !uart_debug)
 327                 device_init_wakeup(&pdev->dev, true);
 328 }
 329
 330 /**
 331  * omap_serial_board_init() - initialize all supported serial ports
 332  * @info: platform specific data pointer
 333  *
 334  * Initializes all available UARTs as serial ports. Platforms
 335  * can call this function when they want to have default behaviour
 336  * for serial ports (e.g initialize them all as serial ports).
 337  */
 338 void __init omap_serial_board_init(struct omap_uart_port_info *info)
 339 {
 340         struct omap_uart_state *uart;
 341         struct omap_board_data bdata;
 342
 343         list_for_each_entry(uart, &uart_list, node) {
 344                 bdata.id = uart->num;
 345                 bdata.flags = 0;
 346                 bdata.pads = NULL;
 347                 bdata.pads_cnt = 0;
 348
 349                 omap_serial_check_wakeup(&bdata, uart);
 350
 351                 if (!info)
 352                         omap_serial_init_port(&bdata, NULL);
 353                 else
 354                         omap_serial_init_port(&bdata, &info[uart->num]);
 355         }
 356 }
 357
 358 /**
 359  * omap_serial_init() - initialize all supported serial ports
 360  *
 361  * Initializes all available UARTs.
 362  * Platforms can call this function when they want to have default behaviour
 363  * for serial ports (e.g initialize them all as serial ports).
 364  */
 365 void __init omap_serial_init(void)
 366 {
 367         omap_serial_board_init(NULL);
 368 }