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 #include <linux/omap-dma.h>
  30 #include <linux/platform_data/serial-omap.h>
  31
  32 #include "common.h"
  33 #include "omap_hwmod.h"
  34 #include "omap_device.h"
  35 #include "omap-pm.h"
  36 #include "soc.h"
  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 #include "serial.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 device *dev, bool enable)
  85 {
  86         struct platform_device *pdev = to_platform_device(dev);
  87         struct omap_device *od = to_omap_device(pdev);
  88
  89         if (!od)
  90                 return;
  91
  92         if (enable)
  93                 omap_hwmod_enable_wakeup(od->hwmods[0]);
  94         else
  95                 omap_hwmod_disable_wakeup(od->hwmods[0]);
  96 }
  97
  98 #else
  99 static void omap_uart_enable_wakeup(struct device *dev, bool enable)
 100 {}
 101 #endif /* CONFIG_PM */
 102
 103 #ifdef CONFIG_OMAP_MUX
 104
 105 #define OMAP_UART_DEFAULT_PAD_NAME_LEN  28
 106 static char rx_pad_name[OMAP_UART_DEFAULT_PAD_NAME_LEN],
 107                 tx_pad_name[OMAP_UART_DEFAULT_PAD_NAME_LEN] __initdata;
 108
 109 static void  __init
 110 omap_serial_fill_uart_tx_rx_pads(struct omap_board_data *bdata,
 111                                 struct omap_uart_state *uart)
 112 {
 113         uart->default_omap_uart_pads[0].name = rx_pad_name;
 114         uart->default_omap_uart_pads[0].flags = OMAP_DEVICE_PAD_REMUX |
 115                                                         OMAP_DEVICE_PAD_WAKEUP;
 116         uart->default_omap_uart_pads[0].enable = OMAP_PIN_INPUT |
 117                                                         OMAP_MUX_MODE0;
 118         uart->default_omap_uart_pads[0].idle = OMAP_PIN_INPUT | OMAP_MUX_MODE0;
 119         uart->default_omap_uart_pads[1].name = tx_pad_name;
 120         uart->default_omap_uart_pads[1].enable = OMAP_PIN_OUTPUT |
 121                                                         OMAP_MUX_MODE0;
 122         bdata->pads = uart->default_omap_uart_pads;
 123         bdata->pads_cnt = ARRAY_SIZE(uart->default_omap_uart_pads);
 124 }
 125
 126 static void  __init omap_serial_check_wakeup(struct omap_board_data *bdata,
 127                                                 struct omap_uart_state *uart)
 128 {
 129         struct omap_mux_partition *tx_partition = NULL, *rx_partition = NULL;
 130         struct omap_mux *rx_mux = NULL, *tx_mux = NULL;
 131         char *rx_fmt, *tx_fmt;
 132         int uart_nr = bdata->id + 1;
 133
 134         if (bdata->id != 2) {
 135                 rx_fmt = "uart%d_rx.uart%d_rx";
 136                 tx_fmt = "uart%d_tx.uart%d_tx";
 137         } else {
 138                 rx_fmt = "uart%d_rx_irrx.uart%d_rx_irrx";
 139                 tx_fmt = "uart%d_tx_irtx.uart%d_tx_irtx";
 140         }
 141
 142         snprintf(rx_pad_name, OMAP_UART_DEFAULT_PAD_NAME_LEN, rx_fmt,
 143                         uart_nr, uart_nr);
 144         snprintf(tx_pad_name, OMAP_UART_DEFAULT_PAD_NAME_LEN, tx_fmt,
 145                         uart_nr, uart_nr);
 146
 147         if (omap_mux_get_by_name(rx_pad_name, &rx_partition, &rx_mux) >= 0 &&
 148                         omap_mux_get_by_name
 149                                 (tx_pad_name, &tx_partition, &tx_mux) >= 0) {
 150                 u16 tx_mode, rx_mode;
 151
 152                 tx_mode = omap_mux_read(tx_partition, tx_mux->reg_offset);
 153                 rx_mode = omap_mux_read(rx_partition, rx_mux->reg_offset);
 154
 155                 /*
 156                  * Check if uart is used in default tx/rx mode i.e. in mux mode0
 157                  * if yes then configure rx pin for wake up capability
 158                  */
 159                 if (OMAP_MODE_UART(rx_mode) && OMAP_MODE_UART(tx_mode))
 160                         omap_serial_fill_uart_tx_rx_pads(bdata, uart);
 161         }
 162 }
 163 #else
 164 static void __init omap_serial_check_wakeup(struct omap_board_data *bdata,
 165                 struct omap_uart_state *uart)
 166 {
 167 }
 168 #endif
 169
 170 static char *cmdline_find_option(char *str)
 171 {
 172         extern char *saved_command_line;
 173
 174         return strstr(saved_command_line, str);
 175 }
 176
 177 static int __init omap_serial_early_init(void)
 178 {
 179         do {
 180                 char oh_name[MAX_UART_HWMOD_NAME_LEN];
 181                 struct omap_hwmod *oh;
 182                 struct omap_uart_state *uart;
 183                 char uart_name[MAX_UART_HWMOD_NAME_LEN];
 184
 185                 snprintf(oh_name, MAX_UART_HWMOD_NAME_LEN,
 186                          "uart%d", num_uarts + 1);
 187                 oh = omap_hwmod_lookup(oh_name);
 188                 if (!oh)
 189                         break;
 190
 191                 uart = kzalloc(sizeof(struct omap_uart_state), GFP_KERNEL);
 192                 if (WARN_ON(!uart))
 193                         return -ENODEV;
 194
 195                 uart->oh = oh;
 196                 uart->num = num_uarts++;
 197                 list_add_tail(&uart->node, &uart_list);
 198                 snprintf(uart_name, MAX_UART_HWMOD_NAME_LEN,
 199                                 "%s%d", OMAP_SERIAL_NAME, uart->num);
 200
 201                 if (cmdline_find_option(uart_name)) {
 202                         console_uart_id = uart->num;
 203
 204                         if (console_loglevel >= 10) {
 205                                 uart_debug = true;
 206                                 pr_info("%s used as console in debug mode: uart%d clocks will not be gated",
 207                                         uart_name, uart->num);
 208                         }
 209
 210                         if (cmdline_find_option("no_console_suspend"))
 211                                 no_console_suspend = true;
 212
 213                         /*
 214                          * omap-uart can be used for earlyprintk logs
 215                          * So if omap-uart is used as console then prevent
 216                          * uart reset and idle to get logs from omap-uart
 217                          * until uart console driver is available to take
 218                          * care for console messages.
 219                          * Idling or resetting omap-uart while printing logs
 220                          * early boot logs can stall the boot-up.
 221                          */
 222                         oh->flags |= HWMOD_INIT_NO_IDLE | HWMOD_INIT_NO_RESET;
 223                 }
 224         } while (1);
 225
 226         return 0;
 227 }
 228 omap_core_initcall(omap_serial_early_init);
 229
 230 /**
 231  * omap_serial_init_port() - initialize single serial port
 232  * @bdata: port specific board data pointer
 233  * @info: platform specific data pointer
 234  *
 235  * This function initialies serial driver for given port only.
 236  * Platforms can call this function instead of omap_serial_init()
 237  * if they don't plan to use all available UARTs as serial ports.
 238  *
 239  * Don't mix calls to omap_serial_init_port() and omap_serial_init(),
 240  * use only one of the two.
 241  */
 242 void __init omap_serial_init_port(struct omap_board_data *bdata,
 243                         struct omap_uart_port_info *info)
 244 {
 245         struct omap_uart_state *uart;
 246         struct omap_hwmod *oh;
 247         struct platform_device *pdev;
 248         void *pdata = NULL;
 249         u32 pdata_size = 0;
 250         char *name;
 251         struct omap_uart_port_info omap_up;
 252
 253         if (WARN_ON(!bdata))
 254                 return;
 255         if (WARN_ON(bdata->id < 0))
 256                 return;
 257         if (WARN_ON(bdata->id >= num_uarts))
 258                 return;
 259
 260         list_for_each_entry(uart, &uart_list, node)
 261                 if (bdata->id == uart->num)
 262                         break;
 263         if (!info)
 264                 info = omap_serial_default_info;
 265
 266         oh = uart->oh;
 267         name = DRIVER_NAME;
 268
 269         omap_up.dma_enabled = info->dma_enabled;
 270         omap_up.uartclk = OMAP24XX_BASE_BAUD * 16;
 271         omap_up.flags = UPF_BOOT_AUTOCONF;
 272         omap_up.get_context_loss_count = omap_pm_get_dev_context_loss_count;
 273         omap_up.enable_wakeup = omap_uart_enable_wakeup;
 274         omap_up.dma_rx_buf_size = info->dma_rx_buf_size;
 275         omap_up.dma_rx_timeout = info->dma_rx_timeout;
 276         omap_up.dma_rx_poll_rate = info->dma_rx_poll_rate;
 277         omap_up.autosuspend_timeout = info->autosuspend_timeout;
 278         omap_up.DTR_gpio = info->DTR_gpio;
 279         omap_up.DTR_inverted = info->DTR_inverted;
 280         omap_up.DTR_present = info->DTR_present;
 281
 282         pdata = &omap_up;
 283         pdata_size = sizeof(struct omap_uart_port_info);
 284
 285         if (WARN_ON(!oh))
 286                 return;
 287
 288         pdev = omap_device_build(name, uart->num, oh, pdata, pdata_size);
 289         if (IS_ERR(pdev)) {
 290                 WARN(1, "Could not build omap_device for %s: %s.\n", name,
 291                      oh->name);
 292                 return;
 293         }
 294
 295         if ((console_uart_id == bdata->id) && no_console_suspend)
 296                 omap_device_disable_idle_on_suspend(pdev);
 297
 298         oh->mux = omap_hwmod_mux_init(bdata->pads, bdata->pads_cnt);
 299
 300         if (console_uart_id == bdata->id) {
 301                 omap_device_enable(pdev);
 302                 pm_runtime_set_active(&pdev->dev);
 303         }
 304
 305         oh->dev_attr = uart;
 306
 307         if (((cpu_is_omap34xx() || cpu_is_omap44xx()) && bdata->pads)
 308                         && !uart_debug)
 309                 device_init_wakeup(&pdev->dev, true);
 310 }
 311
 312 /**
 313  * omap_serial_board_init() - initialize all supported serial ports
 314  * @info: platform specific data pointer
 315  *
 316  * Initializes all available UARTs as serial ports. Platforms
 317  * can call this function when they want to have default behaviour
 318  * for serial ports (e.g initialize them all as serial ports).
 319  */
 320 void __init omap_serial_board_init(struct omap_uart_port_info *info)
 321 {
 322         struct omap_uart_state *uart;
 323         struct omap_board_data bdata;
 324
 325         list_for_each_entry(uart, &uart_list, node) {
 326                 bdata.id = uart->num;
 327                 bdata.flags = 0;
 328                 bdata.pads = NULL;
 329                 bdata.pads_cnt = 0;
 330
 331                 omap_serial_check_wakeup(&bdata, uart);
 332
 333                 if (!info)
 334                         omap_serial_init_port(&bdata, NULL);
 335                 else
 336                         omap_serial_init_port(&bdata, &info[uart->num]);
 337         }
 338 }
 339
 340 /**
 341  * omap_serial_init() - initialize all supported serial ports
 342  *
 343  * Initializes all available UARTs.
 344  * Platforms can call this function when they want to have default behaviour
 345  * for serial ports (e.g initialize them all as serial ports).
 346  */
 347 void __init omap_serial_init(void)
 348 {
 349         omap_serial_board_init(NULL);
 350 }