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/board.h>
  33 #include <plat/dma.h>
  34 #include <plat/omap_hwmod.h>
  35 #include <plat/omap_device.h>
  36 #include <plat/omap-pm.h>
  37
  38 #include "prm2xxx_3xxx.h"
  39 #include "pm.h"
  40 #include "cm2xxx_3xxx.h"
  41 #include "prm-regbits-34xx.h"
  42 #include "control.h"
  43 #include "mux.h"
  44
  45 /*
  46  * NOTE: By default the serial auto_suspend timeout is disabled as it causes
  47  * lost characters over the serial ports. This means that the UART clocks will
  48  * stay on until power/autosuspend_delay is set for the uart from sysfs.
  49  * This also causes that any deeper omap sleep states are blocked.
  50  */
  51 #define DEFAULT_AUTOSUSPEND_DELAY       -1
  52
  53 #define MAX_UART_HWMOD_NAME_LEN         16
  54
  55 struct omap_uart_state {
  56         int num;
  57
  58         struct list_head node;
  59         struct omap_hwmod *oh;
  60         struct omap_device_pad default_omap_uart_pads[2];
  61 };
  62
  63 static LIST_HEAD(uart_list);
  64 static u8 num_uarts;
  65 static u8 console_uart_id = -1;
  66 static u8 no_console_suspend;
  67 static u8 uart_debug;
  68
  69 #define DEFAULT_RXDMA_POLLRATE          1       /* RX DMA polling rate (us) */
  70 #define DEFAULT_RXDMA_BUFSIZE           4096    /* RX DMA buffer size */
  71 #define DEFAULT_RXDMA_TIMEOUT           (3 * HZ)/* RX DMA timeout (jiffies) */
  72
  73 static struct omap_uart_port_info omap_serial_default_info[] __initdata = {
  74         {
  75                 .dma_enabled    = false,
  76                 .dma_rx_buf_size = DEFAULT_RXDMA_BUFSIZE,
  77                 .dma_rx_poll_rate = DEFAULT_RXDMA_POLLRATE,
  78                 .dma_rx_timeout = DEFAULT_RXDMA_TIMEOUT,
  79                 .autosuspend_timeout = DEFAULT_AUTOSUSPEND_DELAY,
  80         },
  81 };
  82
  83 #ifdef CONFIG_PM
  84 static void omap_uart_enable_wakeup(struct platform_device *pdev, bool enable)
  85 {
  86         struct omap_device *od = to_omap_device(pdev);
  87
  88         if (!od)
  89                 return;
  90
  91         if (enable)
  92                 omap_hwmod_enable_wakeup(od->hwmods[0]);
  93         else
  94                 omap_hwmod_disable_wakeup(od->hwmods[0]);
  95 }
  96
  97 /*
  98  * Errata i291: [UART]:Cannot Acknowledge Idle Requests
  99  * in Smartidle Mode When Configured for DMA Operations.
 100  * WA: configure uart in force idle mode.
 101  */
 102 static void omap_uart_set_noidle(struct platform_device *pdev)
 103 {
 104         struct omap_device *od = to_omap_device(pdev);
 105
 106         omap_hwmod_set_slave_idlemode(od->hwmods[0], HWMOD_IDLEMODE_NO);
 107 }
 108
 109 static void omap_uart_set_smartidle(struct platform_device *pdev)
 110 {
 111         struct omap_device *od = to_omap_device(pdev);
 112         u8 idlemode;
 113
 114         if (od->hwmods[0]->class->sysc->idlemodes & SIDLE_SMART_WKUP)
 115                 idlemode = HWMOD_IDLEMODE_SMART_WKUP;
 116         else
 117                 idlemode = HWMOD_IDLEMODE_SMART;
 118
 119         omap_hwmod_set_slave_idlemode(od->hwmods[0], idlemode);
 120 }
 121
 122 #else
 123 static void omap_uart_enable_wakeup(struct platform_device *pdev, bool enable)
 124 {}
 125 static void omap_uart_set_noidle(struct platform_device *pdev) {}
 126 static void omap_uart_set_smartidle(struct platform_device *pdev) {}
 127 #endif /* CONFIG_PM */
 128
 129 #ifdef CONFIG_OMAP_MUX
 130
 131 #define OMAP_UART_DEFAULT_PAD_NAME_LEN  28
 132 static char rx_pad_name[OMAP_UART_DEFAULT_PAD_NAME_LEN],
 133                 tx_pad_name[OMAP_UART_DEFAULT_PAD_NAME_LEN] __initdata;
 134
 135 static void  __init
 136 omap_serial_fill_uart_tx_rx_pads(struct omap_board_data *bdata,
 137                                 struct omap_uart_state *uart)
 138 {
 139         uart->default_omap_uart_pads[0].name = rx_pad_name;
 140         uart->default_omap_uart_pads[0].flags = OMAP_DEVICE_PAD_REMUX |
 141                                                         OMAP_DEVICE_PAD_WAKEUP;
 142         uart->default_omap_uart_pads[0].enable = OMAP_PIN_INPUT |
 143                                                         OMAP_MUX_MODE0;
 144         uart->default_omap_uart_pads[0].idle = OMAP_PIN_INPUT | OMAP_MUX_MODE0;
 145         uart->default_omap_uart_pads[1].name = tx_pad_name;
 146         uart->default_omap_uart_pads[1].enable = OMAP_PIN_OUTPUT |
 147                                                         OMAP_MUX_MODE0;
 148         bdata->pads = uart->default_omap_uart_pads;
 149         bdata->pads_cnt = ARRAY_SIZE(uart->default_omap_uart_pads);
 150 }
 151
 152 static void  __init omap_serial_check_wakeup(struct omap_board_data *bdata,
 153                                                 struct omap_uart_state *uart)
 154 {
 155         struct omap_mux_partition *tx_partition = NULL, *rx_partition = NULL;
 156         struct omap_mux *rx_mux = NULL, *tx_mux = NULL;
 157         char *rx_fmt, *tx_fmt;
 158         int uart_nr = bdata->id + 1;
 159
 160         if (bdata->id != 2) {
 161                 rx_fmt = "uart%d_rx.uart%d_rx";
 162                 tx_fmt = "uart%d_tx.uart%d_tx";
 163         } else {
 164                 rx_fmt = "uart%d_rx_irrx.uart%d_rx_irrx";
 165                 tx_fmt = "uart%d_tx_irtx.uart%d_tx_irtx";
 166         }
 167
 168         snprintf(rx_pad_name, OMAP_UART_DEFAULT_PAD_NAME_LEN, rx_fmt,
 169                         uart_nr, uart_nr);
 170         snprintf(tx_pad_name, OMAP_UART_DEFAULT_PAD_NAME_LEN, tx_fmt,
 171                         uart_nr, uart_nr);
 172
 173         if (omap_mux_get_by_name(rx_pad_name, &rx_partition, &rx_mux) >= 0 &&
 174                         omap_mux_get_by_name
 175                                 (tx_pad_name, &tx_partition, &tx_mux) >= 0) {
 176                 u16 tx_mode, rx_mode;
 177
 178                 tx_mode = omap_mux_read(tx_partition, tx_mux->reg_offset);
 179                 rx_mode = omap_mux_read(rx_partition, rx_mux->reg_offset);
 180
 181                 /*
 182                  * Check if uart is used in default tx/rx mode i.e. in mux mode0
 183                  * if yes then configure rx pin for wake up capability
 184                  */
 185                 if (OMAP_MODE_UART(rx_mode) && OMAP_MODE_UART(tx_mode))
 186                         omap_serial_fill_uart_tx_rx_pads(bdata, uart);
 187         }
 188 }
 189 #else
 190 static void __init omap_serial_check_wakeup(struct omap_board_data *bdata,
 191                 struct omap_uart_state *uart)
 192 {
 193 }
 194 #endif
 195
 196 static char *cmdline_find_option(char *str)
 197 {
 198         extern char *saved_command_line;
 199
 200         return strstr(saved_command_line, str);
 201 }
 202
 203 static int __init omap_serial_early_init(void)
 204 {
 205         do {
 206                 char oh_name[MAX_UART_HWMOD_NAME_LEN];
 207                 struct omap_hwmod *oh;
 208                 struct omap_uart_state *uart;
 209                 char uart_name[MAX_UART_HWMOD_NAME_LEN];
 210
 211                 snprintf(oh_name, MAX_UART_HWMOD_NAME_LEN,
 212                          "uart%d", num_uarts + 1);
 213                 oh = omap_hwmod_lookup(oh_name);
 214                 if (!oh)
 215                         break;
 216
 217                 uart = kzalloc(sizeof(struct omap_uart_state), GFP_KERNEL);
 218                 if (WARN_ON(!uart))
 219                         return -ENODEV;
 220
 221                 uart->oh = oh;
 222                 uart->num = num_uarts++;
 223                 list_add_tail(&uart->node, &uart_list);
 224                 snprintf(uart_name, MAX_UART_HWMOD_NAME_LEN,
 225                                 "%s%d", OMAP_SERIAL_NAME, uart->num);
 226
 227                 if (cmdline_find_option(uart_name)) {
 228                         console_uart_id = uart->num;
 229
 230                         if (console_loglevel >= 10) {
 231                                 uart_debug = true;
 232                                 pr_info("%s used as console in debug mode"
 233                                                 " uart%d clocks will not be"
 234                                                 " gated", uart_name, uart->num);
 235                         }
 236
 237                         if (cmdline_find_option("no_console_suspend"))
 238                                 no_console_suspend = true;
 239
 240                         /*
 241                          * omap-uart can be used for earlyprintk logs
 242                          * So if omap-uart is used as console then prevent
 243                          * uart reset and idle to get logs from omap-uart
 244                          * until uart console driver is available to take
 245                          * care for console messages.
 246                          * Idling or resetting omap-uart while printing logs
 247                          * early boot logs can stall the boot-up.
 248                          */
 249                         oh->flags |= HWMOD_INIT_NO_IDLE | HWMOD_INIT_NO_RESET;
 250                 }
 251         } while (1);
 252
 253         return 0;
 254 }
 255 core_initcall(omap_serial_early_init);
 256
 257 /**
 258  * omap_serial_init_port() - initialize single serial port
 259  * @bdata: port specific board data pointer
 260  * @info: platform specific data pointer
 261  *
 262  * This function initialies serial driver for given port only.
 263  * Platforms can call this function instead of omap_serial_init()
 264  * if they don't plan to use all available UARTs as serial ports.
 265  *
 266  * Don't mix calls to omap_serial_init_port() and omap_serial_init(),
 267  * use only one of the two.
 268  */
 269 void __init omap_serial_init_port(struct omap_board_data *bdata,
 270                         struct omap_uart_port_info *info)
 271 {
 272         struct omap_uart_state *uart;
 273         struct omap_hwmod *oh;
 274         struct platform_device *pdev;
 275         void *pdata = NULL;
 276         u32 pdata_size = 0;
 277         char *name;
 278         struct omap_uart_port_info omap_up;
 279
 280         if (WARN_ON(!bdata))
 281                 return;
 282         if (WARN_ON(bdata->id < 0))
 283                 return;
 284         if (WARN_ON(bdata->id >= num_uarts))
 285                 return;
 286
 287         list_for_each_entry(uart, &uart_list, node)
 288                 if (bdata->id == uart->num)
 289                         break;
 290         if (!info)
 291                 info = omap_serial_default_info;
 292
 293         oh = uart->oh;
 294         name = DRIVER_NAME;
 295
 296         omap_up.dma_enabled = info->dma_enabled;
 297         omap_up.uartclk = OMAP24XX_BASE_BAUD * 16;
 298         omap_up.flags = UPF_BOOT_AUTOCONF;
 299         omap_up.get_context_loss_count = omap_pm_get_dev_context_loss_count;
 300         omap_up.set_forceidle = omap_uart_set_smartidle;
 301         omap_up.set_noidle = omap_uart_set_noidle;
 302         omap_up.enable_wakeup = omap_uart_enable_wakeup;
 303         omap_up.dma_rx_buf_size = info->dma_rx_buf_size;
 304         omap_up.dma_rx_timeout = info->dma_rx_timeout;
 305         omap_up.dma_rx_poll_rate = info->dma_rx_poll_rate;
 306         omap_up.autosuspend_timeout = info->autosuspend_timeout;
 307
 308         pdata = &omap_up;
 309         pdata_size = sizeof(struct omap_uart_port_info);
 310
 311         if (WARN_ON(!oh))
 312                 return;
 313
 314         pdev = omap_device_build(name, uart->num, oh, pdata, pdata_size,
 315                                  NULL, 0, false);
 316         WARN(IS_ERR(pdev), "Could not build omap_device for %s: %s.\n",
 317              name, oh->name);
 318
 319         if ((console_uart_id == bdata->id) && no_console_suspend)
 320                 omap_device_disable_idle_on_suspend(pdev);
 321
 322         oh->mux = omap_hwmod_mux_init(bdata->pads, bdata->pads_cnt);
 323
 324         oh->dev_attr = uart;
 325
 326         if (((cpu_is_omap34xx() || cpu_is_omap44xx()) && bdata->pads)
 327                         && !uart_debug)
 328                 device_init_wakeup(&pdev->dev, true);
 329 }
 330
 331 /**
 332  * omap_serial_board_init() - initialize all supported serial ports
 333  * @info: platform specific data pointer
 334  *
 335  * Initializes all available UARTs as serial ports. Platforms
 336  * can call this function when they want to have default behaviour
 337  * for serial ports (e.g initialize them all as serial ports).
 338  */
 339 void __init omap_serial_board_init(struct omap_uart_port_info *info)
 340 {
 341         struct omap_uart_state *uart;
 342         struct omap_board_data bdata;
 343
 344         list_for_each_entry(uart, &uart_list, node) {
 345                 bdata.id = uart->num;
 346                 bdata.flags = 0;
 347                 bdata.pads = NULL;
 348                 bdata.pads_cnt = 0;
 349
 350                 omap_serial_check_wakeup(&bdata, uart);
 351
 352                 if (!info)
 353                         omap_serial_init_port(&bdata, NULL);
 354                 else
 355                         omap_serial_init_port(&bdata, &info[uart->num]);
 356         }
 357 }
 358
 359 /**
 360  * omap_serial_init() - initialize all supported serial ports
 361  *
 362  * Initializes all available UARTs.
 363  * Platforms can call this function when they want to have default behaviour
 364  * for serial ports (e.g initialize them all as serial ports).
 365  */
 366 void __init omap_serial_init(void)
 367 {
 368         omap_serial_board_init(NULL);
 369 }