/*
 * drivers/serial/mpc52xx_uart.c
 *
 * Driver for the PSC of the Freescale MPC52xx PSCs configured as UARTs.
 *
 * FIXME According to the usermanual the status bits in the status register
 * are only updated when the peripherals access the FIFO and not when the
 * CPU access them. So since we use this bits to know when we stop writing
 * and reading, they may not be updated in-time and a race condition may
 * exists. But I haven't be able to prove this and I don't care. But if
 * any problem arises, it might worth checking. The TX/RX FIFO Stats
 * registers should be used in addition.
 * Update: Actually, they seem updated ... At least the bits we use.
 *
 *
 * Maintainer : Sylvain Munaut <tnt@246tNt.com>
 * 
 * Some of the code has been inspired/copied from the 2.4 code written
 * by Dale Farnsworth <dfarnsworth@mvista.com>.
 * 
 * Copyright (C) 2004 Sylvain Munaut <tnt@246tNt.com>
 * Copyright (C) 2003 MontaVista, Software, Inc.
 * 
 * This file is licensed under the terms of the GNU General Public License
 * version 2. This program is licensed "as is" without any warranty of any
 * kind, whether express or implied.
 */
 
/* OCP Usage :
 *
 * This drivers uses the OCP model. To load the serial driver for one of the
 * PSCs, just add this to the core_ocp table :
 *
 * {
 *      .vendor         = OCP_VENDOR_FREESCALE,
 *      .function       = OCP_FUNC_PSC_UART,
 *      .index          = 0,
 *      .paddr          = MPC52xx_PSC1,
 *      .irq            = MPC52xx_PSC1_IRQ,
 *      .pm             = OCP_CPM_NA,
 * },
 *
 * This is for PSC1, replace the paddr and irq according to the PSC you want to
 * use. The driver all necessary registers to place the PSC in uart mode without
 * DCD. However, the pin multiplexing aren't changed and should be set either
 * by the bootloader or in the platform init code.
 * The index field must be equal to the PSC index ( e.g. 0 for PSC1, 1 for PSC2,
 * and so on). So the PSC1 is mapped to /dev/ttyS0, PSC2 to /dev/ttyS1 and so
 * on. But be warned, it's an ABSOLUTE REQUIREMENT ! This is needed mainly for
 * the console code : without this 1:1 mapping, at early boot time, when we are
 * parsing the kernel args console=ttyS?, we wouldn't know wich PSC it will be
 * mapped to because OCP stuff is not yet initialized.
 */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/tty.h>
#include <linux/serial.h>
#include <linux/sysrq.h>
#include <linux/console.h>

#include <asm/delay.h>
#include <asm/io.h>
#include <asm/ocp.h>

#include <asm/mpc52xx.h>
#include <asm/mpc52xx_psc.h>

#if defined(CONFIG_SERIAL_MPC52xx_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
#define SUPPORT_SYSRQ
#endif

#include <linux/serial_core.h>



#define ISR_PASS_LIMIT 256      /* Max number of iteration in the interrupt */


static struct uart_port mpc52xx_uart_ports[MPC52xx_PSC_MAXNUM];
        /* Rem: - We use the read_status_mask as a shadow of
         *        psc->mpc52xx_psc_imr
         *      - It's important that is array is all zero on start as we
         *        use it to know if it's initialized or not ! If it's not sure
         *        it's cleared, then a memset(...,0,...) should be added to
         *        the console_init
         */

#define PSC(port) ((struct mpc52xx_psc *)((port)->membase))


/* Forward declaration of the interruption handling routine */
static irqreturn_t mpc52xx_uart_int(int irq,void *dev_id,struct pt_regs *regs);


/* Simple macro to test if a port is console or not. This one is taken
 * for serial_core.c and maybe should be moved to serial_core.h ? */
#ifdef CONFIG_SERIAL_CORE_CONSOLE
#define uart_console(port)      ((port)->cons && (port)->cons->index == (port)->line)
#else
#define uart_console(port)      (0)
#endif


/* ======================================================================== */
/* UART operations                                                          */
/* ======================================================================== */

static unsigned int 
mpc52xx_uart_tx_empty(struct uart_port *port)
{
        int status = in_be16(&PSC(port)->mpc52xx_psc_status);
        return (status & MPC52xx_PSC_SR_TXEMP) ? TIOCSER_TEMT : 0;
}

static void 
mpc52xx_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
        /* Not implemented */
}

static unsigned int 
mpc52xx_uart_get_mctrl(struct uart_port *port)
{
        /* Not implemented */
        return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
}

static void 
mpc52xx_uart_stop_tx(struct uart_port *port, unsigned int tty_stop)
{
        /* port->lock taken by caller */
        port->read_status_mask &= ~MPC52xx_PSC_IMR_TXRDY;
        out_be16(&PSC(port)->mpc52xx_psc_imr,port->read_status_mask);
}

static void 
mpc52xx_uart_start_tx(struct uart_port *port, unsigned int tty_start)
{
        /* port->lock taken by caller */
        port->read_status_mask |= MPC52xx_PSC_IMR_TXRDY;
        out_be16(&PSC(port)->mpc52xx_psc_imr,port->read_status_mask);
}

static void 
mpc52xx_uart_send_xchar(struct uart_port *port, char ch)
{
        unsigned long flags;
        spin_lock_irqsave(&port->lock, flags);
        
        port->x_char = ch;
        if (ch) {
                /* Make sure tx interrupts are on */
                /* Truly necessary ??? They should be anyway */
                port->read_status_mask |= MPC52xx_PSC_IMR_TXRDY;
                out_be16(&PSC(port)->mpc52xx_psc_imr,port->read_status_mask);
        }
        
        spin_unlock_irqrestore(&port->lock, flags);
}

static void
mpc52xx_uart_stop_rx(struct uart_port *port)
{
        /* port->lock taken by caller */
        port->read_status_mask &= ~MPC52xx_PSC_IMR_RXRDY;
        out_be16(&PSC(port)->mpc52xx_psc_imr,port->read_status_mask);
}

static void
mpc52xx_uart_enable_ms(struct uart_port *port)
{
        /* Not implemented */
}

static void
mpc52xx_uart_break_ctl(struct uart_port *port, int ctl)
{
        unsigned long flags;
        spin_lock_irqsave(&port->lock, flags);

        if ( ctl == -1 )
                out_8(&PSC(port)->command,MPC52xx_PSC_START_BRK);
        else
                out_8(&PSC(port)->command,MPC52xx_PSC_STOP_BRK);
        
        spin_unlock_irqrestore(&port->lock, flags);
}

static int
mpc52xx_uart_startup(struct uart_port *port)
{
        struct mpc52xx_psc *psc = PSC(port);

        /* Reset/activate the port, clear and enable interrupts */
        out_8(&psc->command,MPC52xx_PSC_RST_RX);
        out_8(&psc->command,MPC52xx_PSC_RST_TX);
        
        out_be32(&psc->sicr,0); /* UART mode DCD ignored */

        out_be16(&psc->mpc52xx_psc_clock_select, 0xdd00); /* /16 prescaler on */
        
        out_8(&psc->rfcntl, 0x00);
        out_be16(&psc->rfalarm, 0x1ff);
        out_8(&psc->tfcntl, 0x07);
        out_be16(&psc->tfalarm, 0x80);

        port->read_status_mask |= MPC52xx_PSC_IMR_RXRDY | MPC52xx_PSC_IMR_TXRDY;
        out_be16(&psc->mpc52xx_psc_imr,port->read_status_mask);
        
        out_8(&psc->command,MPC52xx_PSC_TX_ENABLE);
        out_8(&psc->command,MPC52xx_PSC_RX_ENABLE);
                
        return 0;
}

static void
mpc52xx_uart_shutdown(struct uart_port *port)
{
        struct mpc52xx_psc *psc = PSC(port);
        
        /* Shut down the port, interrupt and all */
        out_8(&psc->command,MPC52xx_PSC_RST_RX);
        out_8(&psc->command,MPC52xx_PSC_RST_TX);
        
        port->read_status_mask = 0; 
        out_be16(&psc->mpc52xx_psc_imr,port->read_status_mask);
}

static void 
mpc52xx_uart_set_termios(struct uart_port *port, struct termios *new,
                         struct termios *old)
{
        struct mpc52xx_psc *psc = PSC(port);
        unsigned long flags;
        unsigned char mr1, mr2;
        unsigned short ctr;
        unsigned int j, baud, quot;
        
        /* Prepare what we're gonna write */
        mr1 = 0;
        
        switch (new->c_cflag & CSIZE) {
                case CS5:       mr1 |= MPC52xx_PSC_MODE_5_BITS;
                                break;
                case CS6:       mr1 |= MPC52xx_PSC_MODE_6_BITS;
                                break;
                case CS7:       mr1 |= MPC52xx_PSC_MODE_7_BITS;
                                break;
                case CS8:
                default:        mr1 |= MPC52xx_PSC_MODE_8_BITS;
        }

        if (new->c_cflag & PARENB) {
                mr1 |= (new->c_cflag & PARODD) ?
                        MPC52xx_PSC_MODE_PARODD : MPC52xx_PSC_MODE_PAREVEN;
        } else
                mr1 |= MPC52xx_PSC_MODE_PARNONE;
        
        
        mr2 = 0;

        if (new->c_cflag & CSTOPB)
                mr2 |= MPC52xx_PSC_MODE_TWO_STOP;
        else
                mr2 |= ((new->c_cflag & CSIZE) == CS5) ?
                        MPC52xx_PSC_MODE_ONE_STOP_5_BITS :
                        MPC52xx_PSC_MODE_ONE_STOP;


        baud = uart_get_baud_rate(port, new, old, 0, port->uartclk/16);
        quot = uart_get_divisor(port, baud);
        ctr = quot & 0xffff;
        
        /* Get the lock */
        spin_lock_irqsave(&port->lock, flags);

        /* Update the per-port timeout */
        uart_update_timeout(port, new->c_cflag, baud);

        /* Do our best to flush TX & RX, so we don't loose anything */
        /* But we don't wait indefinitly ! */
        j = 5000000;    /* Maximum wait */
        /* FIXME Can't receive chars since set_termios might be called at early
         * boot for the console, all stuff is not yet ready to receive at that
         * time and that just makes the kernel oops */
        /* while (j-- && mpc52xx_uart_int_rx_chars(port)); */
        while (!(in_be16(&psc->mpc52xx_psc_status) & MPC52xx_PSC_SR_TXEMP) && 
               --j)
                udelay(1);

        if (!j)
                printk( KERN_ERR "mpc52xx_uart.c: "
                        "Unable to flush RX & TX fifos in-time in set_termios."
                        "Some chars may have been lost.\n" ); 

        /* Reset the TX & RX */
        out_8(&psc->command,MPC52xx_PSC_RST_RX);
        out_8(&psc->command,MPC52xx_PSC_RST_TX);

        /* Send new mode settings */
        out_8(&psc->command,MPC52xx_PSC_SEL_MODE_REG_1);
        out_8(&psc->mode,mr1);
        out_8(&psc->mode,mr2);
        out_8(&psc->ctur,ctr >> 8);
        out_8(&psc->ctlr,ctr & 0xff);
        
        /* Reenable TX & RX */
        out_8(&psc->command,MPC52xx_PSC_TX_ENABLE);
        out_8(&psc->command,MPC52xx_PSC_RX_ENABLE);

        /* We're all set, release the lock */
        spin_unlock_irqrestore(&port->lock, flags);
}

static const char *
mpc52xx_uart_type(struct uart_port *port)
{
        return port->type == PORT_MPC52xx ? "MPC52xx PSC" : NULL;
}

static void
mpc52xx_uart_release_port(struct uart_port *port)
{
        if (port->flags & UPF_IOREMAP) { /* remapped by us ? */
                iounmap(port->membase);
                port->membase = NULL;
        }
}

static int
mpc52xx_uart_request_port(struct uart_port *port)
{
        if (port->flags & UPF_IOREMAP) /* Need to remap ? */
                port->membase = ioremap(port->mapbase, sizeof(struct mpc52xx_psc));
        
        return port->membase != NULL ? 0 : -EBUSY;
}

static void
mpc52xx_uart_config_port(struct uart_port *port, int flags)
{
        if ( (flags & UART_CONFIG_TYPE) &&
             (mpc52xx_uart_request_port(port) == 0) )
                port->type = PORT_MPC52xx;
}

static int
mpc52xx_uart_verify_port(struct uart_port *port, struct serial_struct *ser)
{
        if ( ser->type != PORT_UNKNOWN && ser->type != PORT_MPC52xx )
                return -EINVAL;

        if ( (ser->irq != port->irq) ||
             (ser->io_type != SERIAL_IO_MEM) ||
             (ser->baud_base != port->uartclk)  || 
             // FIXME Should check addresses/irq as well ?
             (ser->hub6 != 0 ) )
                return -EINVAL;

        return 0;
}


static struct uart_ops mpc52xx_uart_ops = {
        .tx_empty       = mpc52xx_uart_tx_empty,
        .set_mctrl      = mpc52xx_uart_set_mctrl,
        .get_mctrl      = mpc52xx_uart_get_mctrl,
        .stop_tx        = mpc52xx_uart_stop_tx,
        .start_tx       = mpc52xx_uart_start_tx,
        .send_xchar     = mpc52xx_uart_send_xchar,
        .stop_rx        = mpc52xx_uart_stop_rx,
        .enable_ms      = mpc52xx_uart_enable_ms,
        .break_ctl      = mpc52xx_uart_break_ctl,
        .startup        = mpc52xx_uart_startup,
        .shutdown       = mpc52xx_uart_shutdown,
        .set_termios    = mpc52xx_uart_set_termios,
/*      .pm             = mpc52xx_uart_pm,              Not supported yet */
/*      .set_wake       = mpc52xx_uart_set_wake,        Not supported yet */
        .type           = mpc52xx_uart_type,
        .release_port   = mpc52xx_uart_release_port,
        .request_port   = mpc52xx_uart_request_port,
        .config_port    = mpc52xx_uart_config_port,
        .verify_port    = mpc52xx_uart_verify_port
};

        
/* ======================================================================== */
/* Interrupt handling                                                       */
/* ======================================================================== */
        
static inline int
mpc52xx_uart_int_rx_chars(struct uart_port *port, struct pt_regs *regs)
{
        struct tty_struct *tty = port->info->tty;
        unsigned char ch;
        unsigned short status;

        /* While we can read, do so ! */
        while ( (status = in_be16(&PSC(port)->mpc52xx_psc_status)) &
                MPC52xx_PSC_SR_RXRDY) {

                /* If we are full, just stop reading */
                if (tty->flip.count >= TTY_FLIPBUF_SIZE)
                        break;
                
                /* Get the char */
                ch = in_8(&PSC(port)->mpc52xx_psc_buffer_8);

                /* Handle sysreq char */
#ifdef SUPPORT_SYSRQ
                if (uart_handle_sysrq_char(port, ch, regs)) {
                        port->sysrq = 0;
                        continue;
                }
#endif

                /* Store it */
                *tty->flip.char_buf_ptr = ch;
                *tty->flip.flag_buf_ptr = 0;
                port->icount.rx++;
        
                if ( status & (MPC52xx_PSC_SR_PE |
                               MPC52xx_PSC_SR_FE |
                               MPC52xx_PSC_SR_RB |
                               MPC52xx_PSC_SR_OE) ) {
                        
                        if (status & MPC52xx_PSC_SR_RB) {
                                *tty->flip.flag_buf_ptr = TTY_BREAK;
                                uart_handle_break(port);
                        } else if (status & MPC52xx_PSC_SR_PE)
                                *tty->flip.flag_buf_ptr = TTY_PARITY;
                        else if (status & MPC52xx_PSC_SR_FE)
                                *tty->flip.flag_buf_ptr = TTY_FRAME;
                        if (status & MPC52xx_PSC_SR_OE) {
                                /*
                                 * Overrun is special, since it's
                                 * reported immediately, and doesn't
                                 * affect the current character
                                 */
                                if (tty->flip.count < (TTY_FLIPBUF_SIZE-1)) {
                                        tty->flip.flag_buf_ptr++;
                                        tty->flip.char_buf_ptr++;
                                        tty->flip.count++;
                                }
                                *tty->flip.flag_buf_ptr = TTY_OVERRUN;
                        }

                        /* Clear error condition */
                        out_8(&PSC(port)->command,MPC52xx_PSC_RST_ERR_STAT);

                }

                tty->flip.char_buf_ptr++;
                tty->flip.flag_buf_ptr++;
                tty->flip.count++;

        }

        tty_flip_buffer_push(tty);
        
        return in_be16(&PSC(port)->mpc52xx_psc_status) & MPC52xx_PSC_SR_RXRDY;
}

static inline int
mpc52xx_uart_int_tx_chars(struct uart_port *port)
{
        struct circ_buf *xmit = &port->info->xmit;

        /* Process out of band chars */
        if (port->x_char) {
                out_8(&PSC(port)->mpc52xx_psc_buffer_8, port->x_char);
                port->icount.tx++;
                port->x_char = 0;
                return 1;
        }

        /* Nothing to do ? */
        if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
                mpc52xx_uart_stop_tx(port,0);
                return 0;
        }

        /* Send chars */
        while (in_be16(&PSC(port)->mpc52xx_psc_status) & MPC52xx_PSC_SR_TXRDY) {
                out_8(&PSC(port)->mpc52xx_psc_buffer_8, xmit->buf[xmit->tail]);
                xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
                port->icount.tx++;
                if (uart_circ_empty(xmit))
                        break;
        }

        /* Wake up */
        if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
                uart_write_wakeup(port);

        /* Maybe we're done after all */
        if (uart_circ_empty(xmit)) {
                mpc52xx_uart_stop_tx(port,0);
                return 0;
        }

        return 1;
}

static irqreturn_t 
mpc52xx_uart_int(int irq, void *dev_id, struct pt_regs *regs)
{
        struct uart_port *port = (struct uart_port *) dev_id;
        unsigned long pass = ISR_PASS_LIMIT;
        unsigned int keepgoing;
        unsigned short status;
        
        if ( irq != port->irq ) {
                printk( KERN_WARNING
                        "mpc52xx_uart_int : " \
                        "Received wrong int %d. Waiting for %d\n",
                       irq, port->irq);
                return IRQ_NONE;
        }
        
        spin_lock(&port->lock);
        
        /* While we have stuff to do, we continue */
        do {
                /* If we don't find anything to do, we stop */
                keepgoing = 0; 
                
                /* Read status */
                status = in_be16(&PSC(port)->mpc52xx_psc_isr);
                status &= port->read_status_mask;
                        
                /* Do we need to receive chars ? */
                /* For this RX interrupts must be on and some chars waiting */
                if ( status & MPC52xx_PSC_IMR_RXRDY )
                        keepgoing |= mpc52xx_uart_int_rx_chars(port, regs);

                /* Do we need to send chars ? */
                /* For this, TX must be ready and TX interrupt enabled */
                if ( status & MPC52xx_PSC_IMR_TXRDY )
                        keepgoing |= mpc52xx_uart_int_tx_chars(port);
                
                /* Limit number of iteration */
                if ( !(--pass) )
                        keepgoing = 0;

        } while (keepgoing);
        
        spin_unlock(&port->lock);
        
        return IRQ_HANDLED;
}


/* ======================================================================== */
/* Console ( if applicable )                                                */
/* ======================================================================== */

#ifdef CONFIG_SERIAL_MPC52xx_CONSOLE

static void __init
mpc52xx_console_get_options(struct uart_port *port,
                            int *baud, int *parity, int *bits, int *flow)
{
        struct mpc52xx_psc *psc = PSC(port);
        unsigned char mr1;

        /* Read the mode registers */
        out_8(&psc->command,MPC52xx_PSC_SEL_MODE_REG_1);
        mr1 = in_8(&psc->mode);
        
        /* CT{U,L}R are write-only ! */
        *baud = __res.bi_baudrate ?
                __res.bi_baudrate : CONFIG_SERIAL_MPC52xx_CONSOLE_BAUD;

        /* Parse them */
        switch (mr1 & MPC52xx_PSC_MODE_BITS_MASK) {
                case MPC52xx_PSC_MODE_5_BITS:   *bits = 5; break;
                case MPC52xx_PSC_MODE_6_BITS:   *bits = 6; break;
                case MPC52xx_PSC_MODE_7_BITS:   *bits = 7; break;
                case MPC52xx_PSC_MODE_8_BITS:
                default:                        *bits = 8;
        }
        
        if (mr1 & MPC52xx_PSC_MODE_PARNONE)
                *parity = 'n';
        else
                *parity = mr1 & MPC52xx_PSC_MODE_PARODD ? 'o' : 'e';
}

static void  
mpc52xx_console_write(struct console *co, const char *s, unsigned int count)
{
        struct uart_port *port = &mpc52xx_uart_ports[co->index];
        struct mpc52xx_psc *psc = PSC(port);
        unsigned int i, j;
        
        /* Disable interrupts */
        out_be16(&psc->mpc52xx_psc_imr, 0);

        /* Wait the TX buffer to be empty */
        j = 5000000;    /* Maximum wait */      
        while (!(in_be16(&psc->mpc52xx_psc_status) & MPC52xx_PSC_SR_TXEMP) && 
               --j)
                udelay(1);

        /* Write all the chars */
        for ( i=0 ; i<count ; i++ ) {
        
                /* Send the char */
                out_8(&psc->mpc52xx_psc_buffer_8, *s);

                /* Line return handling */
                if ( *s++ == '\n' )
                        out_8(&psc->mpc52xx_psc_buffer_8, '\r');
                
                /* Wait the TX buffer to be empty */
                j = 20000;      /* Maximum wait */      
                while (!(in_be16(&psc->mpc52xx_psc_status) & 
                         MPC52xx_PSC_SR_TXEMP) && --j)
                        udelay(1);
        }

        /* Restore interrupt state */
        out_be16(&psc->mpc52xx_psc_imr, port->read_status_mask);
}

static int __init
mpc52xx_console_setup(struct console *co, char *options)
{
        struct uart_port *port = &mpc52xx_uart_ports[co->index];

        int baud = 9600;
        int bits = 8;
        int parity = 'n';
        int flow = 'n';

        if (co->index < 0 || co->index >= MPC52xx_PSC_MAXNUM)
                return -EINVAL;
        
        /* Basic port init. Needed since we use some uart_??? func before
         * real init for early access */
        spin_lock_init(&port->lock);
        port->uartclk   = __res.bi_ipbfreq / 2; /* Look at CTLR doc */
        port->ops       = &mpc52xx_uart_ops;
        port->mapbase   = MPC52xx_PSCx(co->index);

                /* We ioremap ourself */
        port->membase = ioremap(port->mapbase, sizeof(struct mpc52xx_psc));
        if (port->membase == NULL) {
                release_mem_region(port->mapbase, sizeof(struct mpc52xx_psc));
                return -EBUSY;
        }

        /* Setup the port parameters accoding to options */
        if (options)
                uart_parse_options(options, &baud, &parity, &bits, &flow);
        else
                mpc52xx_console_get_options(port, &baud, &parity, &bits, &flow);

        return uart_set_options(port, co, baud, parity, bits, flow);
}


extern struct uart_driver mpc52xx_uart_driver;

static struct console mpc52xx_console = {
        .name   = "ttyS",
        .write  = mpc52xx_console_write,
        .device = uart_console_device,
        .setup  = mpc52xx_console_setup,
        .flags  = CON_PRINTBUFFER,
        .index  = -1,   /* Specified on the cmdline (e.g. console=ttyS0 ) */
        .data   = &mpc52xx_uart_driver,
};

        
static int __init 
mpc52xx_console_init(void)
{
        register_console(&mpc52xx_console);
        return 0;
}

console_initcall(mpc52xx_console_init);

#define MPC52xx_PSC_CONSOLE &mpc52xx_console
#else
#define MPC52xx_PSC_CONSOLE NULL
#endif


/* ======================================================================== */
/* UART Driver                                                              */
/* ======================================================================== */

static struct uart_driver mpc52xx_uart_driver = {
        .owner          = THIS_MODULE,
        .driver_name    = "mpc52xx_psc_uart",
        .dev_name       = "ttyS",
        .devfs_name     = "ttyS",
        .major          = TTY_MAJOR,
        .minor          = 64,
        .nr             = MPC52xx_PSC_MAXNUM,
        .cons           = MPC52xx_PSC_CONSOLE,
};


/* ======================================================================== */
/* OCP Driver                                                               */
/* ======================================================================== */

static int __devinit
mpc52xx_uart_probe(struct ocp_device *ocp)
{
        struct uart_port *port = NULL;
        int idx, ret;

        /* Get the corresponding port struct */
        idx = ocp->def->index;
        if (idx < 0 || idx >= MPC52xx_PSC_MAXNUM)
                return -EINVAL;
        
        port = &mpc52xx_uart_ports[idx];

        /* Init the port structure */
        spin_lock_init(&port->lock);
        port->mapbase   = ocp->def->paddr;
        port->irq       = ocp->def->irq;
        port->uartclk   = __res.bi_ipbfreq / 2; /* Look at CTLR doc */
        port->fifosize  = 255; /* Should be 512 ! But it can't be */
                               /* stored in a unsigned char       */
        port->iotype    = UPIO_MEM;
        port->flags     = UPF_BOOT_AUTOCONF |
                          ( uart_console(port) ? 0 : UPF_IOREMAP );
        port->line      = idx;
        port->ops       = &mpc52xx_uart_ops;
        port->read_status_mask = 0;
        
        /* Requests the mem & irqs */
        /* Unlike other serial drivers, we reserve the resources here, so we
         * can detect early if multiple drivers uses the same PSC. Special
         * care must be taken with the console PSC
         */
        ret = request_irq(
                port->irq, mpc52xx_uart_int,
                SA_INTERRUPT | SA_SAMPLE_RANDOM, "mpc52xx_psc_uart", port);
        if (ret)
                goto error;

        ret = request_mem_region(port->mapbase, sizeof(struct mpc52xx_psc),
                                 "mpc52xx_psc_uart") != NULL ? 0 : -EBUSY;
        if (ret)
                goto free_irq;

        /* Add the port to the uart sub-system */
        ret = uart_add_one_port(&mpc52xx_uart_driver, port);
        if (ret)
                goto release_mem;

        ocp_set_drvdata(ocp, (void*)port);

        return 0;


free_irq:
        free_irq(port->irq, mpc52xx_uart_int);

release_mem:
        release_mem_region(port->mapbase, sizeof(struct mpc52xx_psc));

error:
        if (uart_console(port))
                printk( "mpc52xx_uart.c: Error during resource alloction for "
                        "the console port !!! Check that the console PSC is "
                        "not used by another OCP driver !!!\n" );

        return ret;
}

static void
mpc52xx_uart_remove(struct ocp_device *ocp)
{
        struct uart_port *port = (struct uart_port *) ocp_get_drvdata(ocp);

        ocp_set_drvdata(ocp, NULL);

        if (port) {
                uart_remove_one_port(&mpc52xx_uart_driver, port);
                release_mem_region(port->mapbase, sizeof(struct mpc52xx_psc));
                free_irq(port->irq, mpc52xx_uart_int);
        }
}

#ifdef CONFIG_PM
static int
mpc52xx_uart_suspend(struct ocp_device *ocp, u32 state)
{
        struct uart_port *port = (struct uart_port *) ocp_get_drvdata(ocp);

        uart_suspend_port(&mpc52xx_uart_driver, port);

        return 0;
}

static int
mpc52xx_uart_resume(struct ocp_device *ocp)
{
        struct uart_port *port = (struct uart_port *) ocp_get_drvdata(ocp);

        uart_resume_port(&mpc52xx_uart_driver, port);

        return 0;
}
#endif

static struct ocp_device_id mpc52xx_uart_ids[] __devinitdata = {
        { .vendor = OCP_VENDOR_FREESCALE, .function = OCP_FUNC_PSC_UART },
        { .vendor = OCP_VENDOR_INVALID /* Terminating entry */ }
};

MODULE_DEVICE_TABLE(ocp, mpc52xx_uart_ids);

static struct ocp_driver mpc52xx_uart_ocp_driver = {
        .name           = "mpc52xx_psc_uart",
        .id_table       = mpc52xx_uart_ids,
        .probe          = mpc52xx_uart_probe,
        .remove         = mpc52xx_uart_remove,
#ifdef CONFIG_PM
        .suspend        = mpc52xx_uart_suspend,
        .resume         = mpc52xx_uart_resume,
#endif
};


/* ======================================================================== */
/* Module                                                                   */
/* ======================================================================== */

static int __init
mpc52xx_uart_init(void)
{
        int ret;

        printk(KERN_INFO "Serial: MPC52xx PSC driver\n");

        ret = uart_register_driver(&mpc52xx_uart_driver);
        if (ret)
                return ret;

        ret = ocp_register_driver(&mpc52xx_uart_ocp_driver);

        return ret;
}

static void __exit
mpc52xx_uart_exit(void)
{
        ocp_unregister_driver(&mpc52xx_uart_ocp_driver);
        uart_unregister_driver(&mpc52xx_uart_driver);
}


module_init(mpc52xx_uart_init);
module_exit(mpc52xx_uart_exit);

MODULE_AUTHOR("Sylvain Munaut <tnt@246tNt.com>");
MODULE_DESCRIPTION("Freescale MPC52xx PSC UART");
MODULE_LICENSE("GPL");