/*
 * arch/arm/mach-omap2/serial.c
 *
 * OMAP2 serial support.
 *
 * Copyright (C) 2005-2008 Nokia Corporation
 * Author: Paul Mundt <paul.mundt@nokia.com>
 *
 * 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 <santosh.shilimkar@ti.com
 *
 * 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 <linux/omap-dma.h>
#include <linux/platform_data/serial-omap.h>

#include "common.h"
#include "omap_hwmod.h"
#include "omap_device.h"
#include "omap-pm.h"
#include "soc.h"
#include "prm2xxx_3xxx.h"
#include "pm.h"
#include "cm2xxx_3xxx.h"
#include "prm-regbits-34xx.h"
#include "control.h"
#include "mux.h"
#include "serial.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 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]);
}

#else
static void omap_uart_enable_wakeup(struct device *dev, bool enable)
{}
#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)
{
        if (of_have_populated_dt())
                return -ENODEV;

        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 >= CONSOLE_LOGLEVEL_DEBUG) {
                                uart_debug = true;
                                pr_info("%s used as console in debug mode: uart%d clocks will not be gated",
                                        uart_name, uart->num);
                        }
                }
        } while (1);

        return 0;
}
omap_postcore_initcall(omap_serial_early_init);

/**
 * omap_serial_init_port() - initialize single serial port
 * @bdata: port specific board data pointer
 * @info: platform specific data pointer
 *
 * This function initialies serial driver for given port only.
 * Platforms can call this function instead of omap_serial_init()
 * if they don't plan to use all available UARTs as serial ports.
 *
 * Don't mix calls to omap_serial_init_port() and omap_serial_init(),
 * use only one of the two.
 */
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 = OMAP_SERIAL_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.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;

        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);
        if (IS_ERR(pdev)) {
                WARN(1, "Could not build omap_device for %s: %s.\n", name,
                     oh->name);
                return;
        }

        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);
}

/**
 * omap_serial_board_init() - initialize all supported serial ports
 * @info: platform specific data pointer
 *
 * Initializes all available UARTs as serial ports. Platforms
 * can call this function when they want to have default behaviour
 * for serial ports (e.g initialize them all as serial ports).
 */
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]);
        }
}

/**
 * omap_serial_init() - initialize all supported serial ports
 *
 * Initializes all available UARTs.
 * Platforms can call this function when they want to have default behaviour
 * for serial ports (e.g initialize them all as serial ports).
 */
void __init omap_serial_init(void)
{
        omap_serial_board_init(NULL);
}