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 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 device *dev, bool enable)
  84 {
  85         struct platform_device *pdev = to_platform_device(dev);
  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 #else
  98 static void omap_uart_enable_wakeup(struct device *dev, bool enable)
  99 {}
 100 #endif /* CONFIG_PM */
 101
 102 #ifdef CONFIG_OMAP_MUX
 103
 104 #define OMAP_UART_DEFAULT_PAD_NAME_LEN  28
 105 static char rx_pad_name[OMAP_UART_DEFAULT_PAD_NAME_LEN],
 106                 tx_pad_name[OMAP_UART_DEFAULT_PAD_NAME_LEN] __initdata;
 107
 108 static void  __init
 109 omap_serial_fill_uart_tx_rx_pads(struct omap_board_data *bdata,
 110                                 struct omap_uart_state *uart)
 111 {
 112         uart->default_omap_uart_pads[0].name = rx_pad_name;
 113         uart->default_omap_uart_pads[0].flags = OMAP_DEVICE_PAD_REMUX |
 114                                                         OMAP_DEVICE_PAD_WAKEUP;
 115         uart->default_omap_uart_pads[0].enable = OMAP_PIN_INPUT |
 116                                                         OMAP_MUX_MODE0;
 117         uart->default_omap_uart_pads[0].idle = OMAP_PIN_INPUT | OMAP_MUX_MODE0;
 118         uart->default_omap_uart_pads[1].name = tx_pad_name;
 119         uart->default_omap_uart_pads[1].enable = OMAP_PIN_OUTPUT |
 120                                                         OMAP_MUX_MODE0;
 121         bdata->pads = uart->default_omap_uart_pads;
 122         bdata->pads_cnt = ARRAY_SIZE(uart->default_omap_uart_pads);
 123 }
 124
 125 static void  __init omap_serial_check_wakeup(struct omap_board_data *bdata,
 126                                                 struct omap_uart_state *uart)
 127 {
 128         struct omap_mux_partition *tx_partition = NULL, *rx_partition = NULL;
 129         struct omap_mux *rx_mux = NULL, *tx_mux = NULL;
 130         char *rx_fmt, *tx_fmt;
 131         int uart_nr = bdata->id + 1;
 132
 133         if (bdata->id != 2) {
 134                 rx_fmt = "uart%d_rx.uart%d_rx";
 135                 tx_fmt = "uart%d_tx.uart%d_tx";
 136         } else {
 137                 rx_fmt = "uart%d_rx_irrx.uart%d_rx_irrx";
 138                 tx_fmt = "uart%d_tx_irtx.uart%d_tx_irtx";
 139         }
 140
 141         snprintf(rx_pad_name, OMAP_UART_DEFAULT_PAD_NAME_LEN, rx_fmt,
 142                         uart_nr, uart_nr);
 143         snprintf(tx_pad_name, OMAP_UART_DEFAULT_PAD_NAME_LEN, tx_fmt,
 144                         uart_nr, uart_nr);
 145
 146         if (omap_mux_get_by_name(rx_pad_name, &rx_partition, &rx_mux) >= 0 &&
 147                         omap_mux_get_by_name
 148                                 (tx_pad_name, &tx_partition, &tx_mux) >= 0) {
 149                 u16 tx_mode, rx_mode;
 150
 151                 tx_mode = omap_mux_read(tx_partition, tx_mux->reg_offset);
 152                 rx_mode = omap_mux_read(rx_partition, rx_mux->reg_offset);
 153
 154                 /*
 155                  * Check if uart is used in default tx/rx mode i.e. in mux mode0
 156                  * if yes then configure rx pin for wake up capability
 157                  */
 158                 if (OMAP_MODE_UART(rx_mode) && OMAP_MODE_UART(tx_mode))
 159                         omap_serial_fill_uart_tx_rx_pads(bdata, uart);
 160         }
 161 }
 162 #else
 163 static void __init omap_serial_check_wakeup(struct omap_board_data *bdata,
 164                 struct omap_uart_state *uart)
 165 {
 166 }
 167 #endif
 168
 169 static char *cmdline_find_option(char *str)
 170 {
 171         extern char *saved_command_line;
 172
 173         return strstr(saved_command_line, str);
 174 }
 175
 176 static int __init omap_serial_early_init(void)
 177 {
 178         if (of_have_populated_dt())
 179                 return -ENODEV;
 180
 181         do {
 182                 char oh_name[MAX_UART_HWMOD_NAME_LEN];
 183                 struct omap_hwmod *oh;
 184                 struct omap_uart_state *uart;
 185                 char uart_name[MAX_UART_HWMOD_NAME_LEN];
 186
 187                 snprintf(oh_name, MAX_UART_HWMOD_NAME_LEN,
 188                          "uart%d", num_uarts + 1);
 189                 oh = omap_hwmod_lookup(oh_name);
 190                 if (!oh)
 191                         break;
 192
 193                 uart = kzalloc(sizeof(struct omap_uart_state), GFP_KERNEL);
 194                 if (WARN_ON(!uart))
 195                         return -ENODEV;
 196
 197                 uart->oh = oh;
 198                 uart->num = num_uarts++;
 199                 list_add_tail(&uart->node, &uart_list);
 200                 snprintf(uart_name, MAX_UART_HWMOD_NAME_LEN,
 201                                 "%s%d", OMAP_SERIAL_NAME, uart->num);
 202
 203                 if (cmdline_find_option(uart_name)) {
 204                         console_uart_id = uart->num;
 205
 206                         if (console_loglevel >= 10) {
 207                                 uart_debug = true;
 208                                 pr_info("%s used as console in debug mode: uart%d clocks will not be gated",
 209                                         uart_name, uart->num);
 210                         }
 211
 212                         /*
 213                          * omap-uart can be used for earlyprintk logs
 214                          * So if omap-uart is used as console then prevent
 215                          * uart reset and idle to get logs from omap-uart
 216                          * until uart console driver is available to take
 217                          * care for console messages.
 218                          * Idling or resetting omap-uart while printing logs
 219                          * early boot logs can stall the boot-up.
 220                          */
 221                         oh->flags |= HWMOD_INIT_NO_IDLE | HWMOD_INIT_NO_RESET;
 222                 }
 223         } while (1);
 224
 225         return 0;
 226 }
 227 omap_core_initcall(omap_serial_early_init);
 228
 229 /**
 230  * omap_serial_init_port() - initialize single serial port
 231  * @bdata: port specific board data pointer
 232  * @info: platform specific data pointer
 233  *
 234  * This function initialies serial driver for given port only.
 235  * Platforms can call this function instead of omap_serial_init()
 236  * if they don't plan to use all available UARTs as serial ports.
 237  *
 238  * Don't mix calls to omap_serial_init_port() and omap_serial_init(),
 239  * use only one of the two.
 240  */
 241 void __init omap_serial_init_port(struct omap_board_data *bdata,
 242                         struct omap_uart_port_info *info)
 243 {
 244         struct omap_uart_state *uart;
 245         struct omap_hwmod *oh;
 246         struct platform_device *pdev;
 247         void *pdata = NULL;
 248         u32 pdata_size = 0;
 249         char *name;
 250         struct omap_uart_port_info omap_up;
 251
 252         if (WARN_ON(!bdata))
 253                 return;
 254         if (WARN_ON(bdata->id < 0))
 255                 return;
 256         if (WARN_ON(bdata->id >= num_uarts))
 257                 return;
 258
 259         list_for_each_entry(uart, &uart_list, node)
 260                 if (bdata->id == uart->num)
 261                         break;
 262         if (!info)
 263                 info = omap_serial_default_info;
 264
 265         oh = uart->oh;
 266         name = DRIVER_NAME;
 267
 268         omap_up.dma_enabled = info->dma_enabled;
 269         omap_up.uartclk = OMAP24XX_BASE_BAUD * 16;
 270         omap_up.flags = UPF_BOOT_AUTOCONF;
 271         omap_up.get_context_loss_count = omap_pm_get_dev_context_loss_count;
 272         omap_up.enable_wakeup = omap_uart_enable_wakeup;
 273         omap_up.dma_rx_buf_size = info->dma_rx_buf_size;
 274         omap_up.dma_rx_timeout = info->dma_rx_timeout;
 275         omap_up.dma_rx_poll_rate = info->dma_rx_poll_rate;
 276         omap_up.autosuspend_timeout = info->autosuspend_timeout;
 277         omap_up.DTR_gpio = info->DTR_gpio;
 278         omap_up.DTR_inverted = info->DTR_inverted;
 279         omap_up.DTR_present = info->DTR_present;
 280
 281         pdata = &omap_up;
 282         pdata_size = sizeof(struct omap_uart_port_info);
 283
 284         if (WARN_ON(!oh))
 285                 return;
 286
 287         pdev = omap_device_build(name, uart->num, oh, pdata, pdata_size);
 288         if (IS_ERR(pdev)) {
 289                 WARN(1, "Could not build omap_device for %s: %s.\n", name,
 290                      oh->name);
 291                 return;
 292         }
 293
 294         oh->mux = omap_hwmod_mux_init(bdata->pads, bdata->pads_cnt);
 295
 296         if (console_uart_id == bdata->id) {
 297                 omap_device_enable(pdev);
 298                 pm_runtime_set_active(&pdev->dev);
 299         }
 300
 301         oh->dev_attr = uart;
 302
 303         if (((cpu_is_omap34xx() || cpu_is_omap44xx()) && bdata->pads)
 304                         && !uart_debug)
 305                 device_init_wakeup(&pdev->dev, true);
 306 }
 307
 308 /**
 309  * omap_serial_board_init() - initialize all supported serial ports
 310  * @info: platform specific data pointer
 311  *
 312  * Initializes all available UARTs as serial ports. Platforms
 313  * can call this function when they want to have default behaviour
 314  * for serial ports (e.g initialize them all as serial ports).
 315  */
 316 void __init omap_serial_board_init(struct omap_uart_port_info *info)
 317 {
 318         struct omap_uart_state *uart;
 319         struct omap_board_data bdata;
 320
 321         list_for_each_entry(uart, &uart_list, node) {
 322                 bdata.id = uart->num;
 323                 bdata.flags = 0;
 324                 bdata.pads = NULL;
 325                 bdata.pads_cnt = 0;
 326
 327                 omap_serial_check_wakeup(&bdata, uart);
 328
 329                 if (!info)
 330                         omap_serial_init_port(&bdata, NULL);
 331                 else
 332                         omap_serial_init_port(&bdata, &info[uart->num]);
 333         }
 334 }
 335
 336 /**
 337  * omap_serial_init() - initialize all supported serial ports
 338  *
 339  * Initializes all available UARTs.
 340  * Platforms can call this function when they want to have default behaviour
 341  * for serial ports (e.g initialize them all as serial ports).
 342  */
 343 void __init omap_serial_init(void)
 344 {
 345         omap_serial_board_init(NULL);
 346 }