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 };
  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 static void omap_serial_fill_default_pads(struct omap_board_data *bdata)
 130 {
 131 }
 132 #else
 133 static void omap_serial_fill_default_pads(struct omap_board_data *bdata) {}
 134 #endif
 135
 136 static char *cmdline_find_option(char *str)
 137 {
 138         extern char *saved_command_line;
 139
 140         return strstr(saved_command_line, str);
 141 }
 142
 143 static int __init omap_serial_early_init(void)
 144 {
 145         do {
 146                 char oh_name[MAX_UART_HWMOD_NAME_LEN];
 147                 struct omap_hwmod *oh;
 148                 struct omap_uart_state *uart;
 149                 char uart_name[MAX_UART_HWMOD_NAME_LEN];
 150
 151                 snprintf(oh_name, MAX_UART_HWMOD_NAME_LEN,
 152                          "uart%d", num_uarts + 1);
 153                 oh = omap_hwmod_lookup(oh_name);
 154                 if (!oh)
 155                         break;
 156
 157                 uart = kzalloc(sizeof(struct omap_uart_state), GFP_KERNEL);
 158                 if (WARN_ON(!uart))
 159                         return -ENODEV;
 160
 161                 uart->oh = oh;
 162                 uart->num = num_uarts++;
 163                 list_add_tail(&uart->node, &uart_list);
 164                 snprintf(uart_name, MAX_UART_HWMOD_NAME_LEN,
 165                                 "%s%d", OMAP_SERIAL_NAME, uart->num);
 166
 167                 if (cmdline_find_option(uart_name)) {
 168                         console_uart_id = uart->num;
 169
 170                         if (console_loglevel >= 10) {
 171                                 uart_debug = true;
 172                                 pr_info("%s used as console in debug mode"
 173                                                 " uart%d clocks will not be"
 174                                                 " gated", uart_name, uart->num);
 175                         }
 176
 177                         if (cmdline_find_option("no_console_suspend"))
 178                                 no_console_suspend = true;
 179
 180                         /*
 181                          * omap-uart can be used for earlyprintk logs
 182                          * So if omap-uart is used as console then prevent
 183                          * uart reset and idle to get logs from omap-uart
 184                          * until uart console driver is available to take
 185                          * care for console messages.
 186                          * Idling or resetting omap-uart while printing logs
 187                          * early boot logs can stall the boot-up.
 188                          */
 189                         oh->flags |= HWMOD_INIT_NO_IDLE | HWMOD_INIT_NO_RESET;
 190                 }
 191         } while (1);
 192
 193         return 0;
 194 }
 195 core_initcall(omap_serial_early_init);
 196
 197 /**
 198  * omap_serial_init_port() - initialize single serial port
 199  * @bdata: port specific board data pointer
 200  * @info: platform specific data pointer
 201  *
 202  * This function initialies serial driver for given port only.
 203  * Platforms can call this function instead of omap_serial_init()
 204  * if they don't plan to use all available UARTs as serial ports.
 205  *
 206  * Don't mix calls to omap_serial_init_port() and omap_serial_init(),
 207  * use only one of the two.
 208  */
 209 void __init omap_serial_init_port(struct omap_board_data *bdata,
 210                         struct omap_uart_port_info *info)
 211 {
 212         struct omap_uart_state *uart;
 213         struct omap_hwmod *oh;
 214         struct platform_device *pdev;
 215         void *pdata = NULL;
 216         u32 pdata_size = 0;
 217         char *name;
 218         struct omap_uart_port_info omap_up;
 219
 220         if (WARN_ON(!bdata))
 221                 return;
 222         if (WARN_ON(bdata->id < 0))
 223                 return;
 224         if (WARN_ON(bdata->id >= num_uarts))
 225                 return;
 226
 227         list_for_each_entry(uart, &uart_list, node)
 228                 if (bdata->id == uart->num)
 229                         break;
 230         if (!info)
 231                 info = omap_serial_default_info;
 232
 233         oh = uart->oh;
 234         name = DRIVER_NAME;
 235
 236         omap_up.dma_enabled = info->dma_enabled;
 237         omap_up.uartclk = OMAP24XX_BASE_BAUD * 16;
 238         omap_up.flags = UPF_BOOT_AUTOCONF;
 239         omap_up.get_context_loss_count = omap_pm_get_dev_context_loss_count;
 240         omap_up.set_forceidle = omap_uart_set_smartidle;
 241         omap_up.set_noidle = omap_uart_set_noidle;
 242         omap_up.enable_wakeup = omap_uart_enable_wakeup;
 243         omap_up.dma_rx_buf_size = info->dma_rx_buf_size;
 244         omap_up.dma_rx_timeout = info->dma_rx_timeout;
 245         omap_up.dma_rx_poll_rate = info->dma_rx_poll_rate;
 246         omap_up.autosuspend_timeout = info->autosuspend_timeout;
 247
 248         pdata = &omap_up;
 249         pdata_size = sizeof(struct omap_uart_port_info);
 250
 251         if (WARN_ON(!oh))
 252                 return;
 253
 254         pdev = omap_device_build(name, uart->num, oh, pdata, pdata_size,
 255                                  NULL, 0, false);
 256         WARN(IS_ERR(pdev), "Could not build omap_device for %s: %s.\n",
 257              name, oh->name);
 258
 259         if ((console_uart_id == bdata->id) && no_console_suspend)
 260                 omap_device_disable_idle_on_suspend(pdev);
 261
 262         oh->mux = omap_hwmod_mux_init(bdata->pads, bdata->pads_cnt);
 263
 264         oh->dev_attr = uart;
 265
 266         if (((cpu_is_omap34xx() || cpu_is_omap44xx()) && bdata->pads)
 267                         && !uart_debug)
 268                 device_init_wakeup(&pdev->dev, true);
 269 }
 270
 271 /**
 272  * omap_serial_board_init() - initialize all supported serial ports
 273  * @info: platform specific data pointer
 274  *
 275  * Initializes all available UARTs as serial ports. Platforms
 276  * can call this function when they want to have default behaviour
 277  * for serial ports (e.g initialize them all as serial ports).
 278  */
 279 void __init omap_serial_board_init(struct omap_uart_port_info *info)
 280 {
 281         struct omap_uart_state *uart;
 282         struct omap_board_data bdata;
 283
 284         list_for_each_entry(uart, &uart_list, node) {
 285                 bdata.id = uart->num;
 286                 bdata.flags = 0;
 287                 bdata.pads = NULL;
 288                 bdata.pads_cnt = 0;
 289
 290                 if (cpu_is_omap44xx() || cpu_is_omap34xx())
 291                         omap_serial_fill_default_pads(&bdata);
 292
 293                 if (!info)
 294                         omap_serial_init_port(&bdata, NULL);
 295                 else
 296                         omap_serial_init_port(&bdata, &info[uart->num]);
 297         }
 298 }
 299
 300 /**
 301  * omap_serial_init() - initialize all supported serial ports
 302  *
 303  * Initializes all available UARTs.
 304  * Platforms can call this function when they want to have default behaviour
 305  * for serial ports (e.g initialize them all as serial ports).
 306  */
 307 void __init omap_serial_init(void)
 308 {
 309         omap_serial_board_init(NULL);
 310 }