serial.c

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/*
 * arch/arm/mach-omap2/serial.c
 *
 * OMAP2 serial support.
 *
 * Copyright (C) 2005-2008 Nokia Corporation
 * Author: Paul Mundt <[email protected]>
 *
 * Major rework for PM support by Kevin Hilman
 *
 * Based off of arch/arm/mach-omap/omap1/serial.c
 *
 * Copyright (C) 2009 Texas Instruments
 * Added OMAP4 support - Santosh Shilimkar <[email protected]
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License. See the file "COPYING" in the main directory of this archive
 * for more details.
 */
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/pm_runtime.h>
#include <linux/console.h>

#include <plat/omap-serial.h>
#include "common.h"
#include <plat/dma.h>
#include <plat/omap_hwmod.h>
#include <plat/omap_device.h>
#include <plat/omap-pm.h>
#include <plat/serial.h>

#include "prm2xxx_3xxx.h"
#include "pm.h"
#include "cm2xxx_3xxx.h"
#include "prm-regbits-34xx.h"
#include "control.h"
#include "mux.h"

/*
 * NOTE: By default the serial auto_suspend timeout is disabled as it causes
 * lost characters over the serial ports. This means that the UART clocks will
 * stay on until power/autosuspend_delay is set for the uart from sysfs.
 * This also causes that any deeper omap sleep states are blocked.
 */
#define DEFAULT_AUTOSUSPEND_DELAY   -1

#define MAX_UART_HWMOD_NAME_LEN     16

struct omap_uart_state {
    int num;

    struct list_head node;
    struct omap_hwmod *oh;
    struct omap_device_pad default_omap_uart_pads[2];
};

static LIST_HEAD(uart_list);
static u8 num_uarts;
static u8 console_uart_id = -1;
static u8 no_console_suspend;
static u8 uart_debug;

#define DEFAULT_RXDMA_POLLRATE      1   /* RX DMA polling rate (us) */
#define DEFAULT_RXDMA_BUFSIZE       4096    /* RX DMA buffer size */
#define DEFAULT_RXDMA_TIMEOUT       (3 * HZ)/* RX DMA timeout (jiffies) */

static struct omap_uart_port_info omap_serial_default_info[] __initdata = {
    {
        .dma_enabled    = false,
        .dma_rx_buf_size = DEFAULT_RXDMA_BUFSIZE,
        .dma_rx_poll_rate = DEFAULT_RXDMA_POLLRATE,
        .dma_rx_timeout = DEFAULT_RXDMA_TIMEOUT,
        .autosuspend_timeout = DEFAULT_AUTOSUSPEND_DELAY,
    },
};

#ifdef CONFIG_PM
static void omap_uart_enable_wakeup(struct device *dev, bool enable)
{
    struct platform_device *pdev = to_platform_device(dev);
    struct omap_device *od = to_omap_device(pdev);

    if (!od)
        return;

    if (enable)
        omap_hwmod_enable_wakeup(od->hwmods[0]);
    else
        omap_hwmod_disable_wakeup(od->hwmods[0]);
}

/*
 * Errata i291: [UART]:Cannot Acknowledge Idle Requests
 * in Smartidle Mode When Configured for DMA Operations.
 * WA: configure uart in force idle mode.
 */
static void omap_uart_set_noidle(struct device *dev)
{
    struct platform_device *pdev = to_platform_device(dev);
    struct omap_device *od = to_omap_device(pdev);

    omap_hwmod_set_slave_idlemode(od->hwmods[0], HWMOD_IDLEMODE_NO);
}

static void omap_uart_set_smartidle(struct device *dev)
{
    struct platform_device *pdev = to_platform_device(dev);
    struct omap_device *od = to_omap_device(pdev);
    u8 idlemode;

    if (od->hwmods[0]->class->sysc->idlemodes & SIDLE_SMART_WKUP)
        idlemode = HWMOD_IDLEMODE_SMART_WKUP;
    else
        idlemode = HWMOD_IDLEMODE_SMART;

    omap_hwmod_set_slave_idlemode(od->hwmods[0], idlemode);
}

#else
static void omap_uart_enable_wakeup(struct device *dev, bool enable)
{}
static void omap_uart_set_noidle(struct device *dev) {}
static void omap_uart_set_smartidle(struct device *dev) {}
#endif /* CONFIG_PM */

#ifdef CONFIG_OMAP_MUX

#define OMAP_UART_DEFAULT_PAD_NAME_LEN  28
static char rx_pad_name[OMAP_UART_DEFAULT_PAD_NAME_LEN],
        tx_pad_name[OMAP_UART_DEFAULT_PAD_NAME_LEN] __initdata;

static void  __init
omap_serial_fill_uart_tx_rx_pads(struct omap_board_data *bdata,
                struct omap_uart_state *uart)
{
    uart->default_omap_uart_pads[0].name = rx_pad_name;
    uart->default_omap_uart_pads[0].flags = OMAP_DEVICE_PAD_REMUX |
                            OMAP_DEVICE_PAD_WAKEUP;
    uart->default_omap_uart_pads[0].enable = OMAP_PIN_INPUT |
                            OMAP_MUX_MODE0;
    uart->default_omap_uart_pads[0].idle = OMAP_PIN_INPUT | OMAP_MUX_MODE0;
    uart->default_omap_uart_pads[1].name = tx_pad_name;
    uart->default_omap_uart_pads[1].enable = OMAP_PIN_OUTPUT |
                            OMAP_MUX_MODE0;
    bdata->pads = uart->default_omap_uart_pads;
    bdata->pads_cnt = ARRAY_SIZE(uart->default_omap_uart_pads);
}

static void  __init omap_serial_check_wakeup(struct omap_board_data *bdata,
                        struct omap_uart_state *uart)
{
    struct omap_mux_partition *tx_partition = NULL, *rx_partition = NULL;
    struct omap_mux *rx_mux = NULL, *tx_mux = NULL;
    char *rx_fmt, *tx_fmt;
    int uart_nr = bdata->id + 1;

    if (bdata->id != 2) {
        rx_fmt = "uart%d_rx.uart%d_rx";
        tx_fmt = "uart%d_tx.uart%d_tx";
    } else {
        rx_fmt = "uart%d_rx_irrx.uart%d_rx_irrx";
        tx_fmt = "uart%d_tx_irtx.uart%d_tx_irtx";
    }

    snprintf(rx_pad_name, OMAP_UART_DEFAULT_PAD_NAME_LEN, rx_fmt,
            uart_nr, uart_nr);
    snprintf(tx_pad_name, OMAP_UART_DEFAULT_PAD_NAME_LEN, tx_fmt,
            uart_nr, uart_nr);

    if (omap_mux_get_by_name(rx_pad_name, &rx_partition, &rx_mux) >= 0 &&
            omap_mux_get_by_name
                (tx_pad_name, &tx_partition, &tx_mux) >= 0) {
        u16 tx_mode, rx_mode;

        tx_mode = omap_mux_read(tx_partition, tx_mux->reg_offset);
        rx_mode = omap_mux_read(rx_partition, rx_mux->reg_offset);

        /*
         * Check if uart is used in default tx/rx mode i.e. in mux mode0
         * if yes then configure rx pin for wake up capability
         */
        if (OMAP_MODE_UART(rx_mode) && OMAP_MODE_UART(tx_mode))
            omap_serial_fill_uart_tx_rx_pads(bdata, uart);
    }
}
#else
static void __init omap_serial_check_wakeup(struct omap_board_data *bdata,
        struct omap_uart_state *uart)
{
}
#endif

static char *cmdline_find_option(char *str)
{
    extern char *saved_command_line;

    return strstr(saved_command_line, str);
}

static int __init omap_serial_early_init(void)
{
    do {
        char oh_name[MAX_UART_HWMOD_NAME_LEN];
        struct omap_hwmod *oh;
        struct omap_uart_state *uart;
        char uart_name[MAX_UART_HWMOD_NAME_LEN];

        snprintf(oh_name, MAX_UART_HWMOD_NAME_LEN,
             "uart%d", num_uarts + 1);
        oh = omap_hwmod_lookup(oh_name);
        if (!oh)
            break;

        uart = kzalloc(sizeof(struct omap_uart_state), GFP_KERNEL);
        if (WARN_ON(!uart))
            return -ENODEV;

        uart->oh = oh;
        uart->num = num_uarts++;
        list_add_tail(&uart->node, &uart_list);
        snprintf(uart_name, MAX_UART_HWMOD_NAME_LEN,
                "%s%d", OMAP_SERIAL_NAME, uart->num);

        if (cmdline_find_option(uart_name)) {
            console_uart_id = uart->num;

            if (console_loglevel >= 10) {
                uart_debug = true;
                pr_info("%s used as console in debug mode: uart%d clocks will not be gated",
                    uart_name, uart->num);
            }

            if (cmdline_find_option("no_console_suspend"))
                no_console_suspend = true;

            /*
             * omap-uart can be used for earlyprintk logs
             * So if omap-uart is used as console then prevent
             * uart reset and idle to get logs from omap-uart
             * until uart console driver is available to take
             * care for console messages.
             * Idling or resetting omap-uart while printing logs
             * early boot logs can stall the boot-up.
             */
            oh->flags |= HWMOD_INIT_NO_IDLE | HWMOD_INIT_NO_RESET;
        }
    } while (1);

    return 0;
}
core_initcall(omap_serial_early_init);

void __init omap_serial_init_port(struct omap_board_data *bdata,
            struct omap_uart_port_info *info)
{
    struct omap_uart_state *uart;
    struct omap_hwmod *oh;
    struct platform_device *pdev;
    void *pdata = NULL;
    u32 pdata_size = 0;
    char *name;
    struct omap_uart_port_info omap_up;

    if (WARN_ON(!bdata))
        return;
    if (WARN_ON(bdata->id < 0))
        return;
    if (WARN_ON(bdata->id >= num_uarts))
        return;

    list_for_each_entry(uart, &uart_list, node)
        if (bdata->id == uart->num)
            break;
    if (!info)
        info = omap_serial_default_info;

    oh = uart->oh;
    name = DRIVER_NAME;

    omap_up.dma_enabled = info->dma_enabled;
    omap_up.uartclk = OMAP24XX_BASE_BAUD * 16;
    omap_up.flags = UPF_BOOT_AUTOCONF;
    omap_up.get_context_loss_count = omap_pm_get_dev_context_loss_count;
    omap_up.set_forceidle = omap_uart_set_smartidle;
    omap_up.set_noidle = omap_uart_set_noidle;
    omap_up.enable_wakeup = omap_uart_enable_wakeup;
    omap_up.dma_rx_buf_size = info->dma_rx_buf_size;
    omap_up.dma_rx_timeout = info->dma_rx_timeout;
    omap_up.dma_rx_poll_rate = info->dma_rx_poll_rate;
    omap_up.autosuspend_timeout = info->autosuspend_timeout;
    omap_up.DTR_gpio = info->DTR_gpio;
    omap_up.DTR_inverted = info->DTR_inverted;
    omap_up.DTR_present = info->DTR_present;

    pdata = &omap_up;
    pdata_size = sizeof(struct omap_uart_port_info);

    if (WARN_ON(!oh))
        return;

    pdev = omap_device_build(name, uart->num, oh, pdata, pdata_size,
                 NULL, 0, false);
    if (IS_ERR(pdev)) {
        WARN(1, "Could not build omap_device for %s: %s.\n", name,
             oh->name);
        return;
    }

    if ((console_uart_id == bdata->id) && no_console_suspend)
        omap_device_disable_idle_on_suspend(pdev);

    oh->mux = omap_hwmod_mux_init(bdata->pads, bdata->pads_cnt);

    if (console_uart_id == bdata->id) {
        omap_device_enable(pdev);
        pm_runtime_set_active(&pdev->dev);
    }

    oh->dev_attr = uart;

    if (((cpu_is_omap34xx() || cpu_is_omap44xx()) && bdata->pads)
            && !uart_debug)
        device_init_wakeup(&pdev->dev, true);
}

void __init omap_serial_board_init(struct omap_uart_port_info *info)
{
    struct omap_uart_state *uart;
    struct omap_board_data bdata;

    list_for_each_entry(uart, &uart_list, node) {
        bdata.id = uart->num;
        bdata.flags = 0;
        bdata.pads = NULL;
        bdata.pads_cnt = 0;

        omap_serial_check_wakeup(&bdata, uart);

        if (!info)
            omap_serial_init_port(&bdata, NULL);
        else
            omap_serial_init_port(&bdata, &info[uart->num]);
    }
}

void __init omap_serial_init(void)
{
    omap_serial_board_init(NULL);
}