/*
 * (c) 2004 Sascha Hauer <sascha@saschahauer.de>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#include <common.h>
#include <asm/arch/imx-regs.h>

#if defined CONFIG_IMX_SERIAL1
#define UART_BASE IMX_UART1_BASE
#elif defined CONFIG_IMX_SERIAL2
#define UART_BASE IMX_UART2_BASE
#else
#error "define CONFIG_IMX_SERIAL1, CONFIG_IMX_SERIAL2 or CONFIG_IMX_SERIAL_NONE"
#endif

struct imx_serial {
        volatile uint32_t urxd[16];
        volatile uint32_t utxd[16];
        volatile uint32_t ucr1;
        volatile uint32_t ucr2;
        volatile uint32_t ucr3;
        volatile uint32_t ucr4;
        volatile uint32_t ufcr;
        volatile uint32_t usr1;
        volatile uint32_t usr2;
        volatile uint32_t uesc;
        volatile uint32_t utim;
        volatile uint32_t ubir;
        volatile uint32_t ubmr;
        volatile uint32_t ubrc;
        volatile uint32_t bipr[4];
        volatile uint32_t bmpr[4];
        volatile uint32_t uts;
};

DECLARE_GLOBAL_DATA_PTR;

void serial_setbrg (void)
{
        serial_init();
}

extern void imx_gpio_mode(int gpio_mode);

/*
 * Initialise the serial port with the given baudrate. The settings
 * are always 8 data bits, no parity, 1 stop bit, no start bits.
 *
 */
int serial_init (void)
{
        volatile struct imx_serial* base = (struct imx_serial *)UART_BASE;
        unsigned int ufcr_rfdiv;
        unsigned int refclk;

#ifdef CONFIG_IMX_SERIAL1
        imx_gpio_mode(PC11_PF_UART1_TXD);
        imx_gpio_mode(PC12_PF_UART1_RXD);
#else
        imx_gpio_mode(PB30_PF_UART2_TXD);
        imx_gpio_mode(PB31_PF_UART2_RXD);
#endif

        /* Disable UART */
        base->ucr1 &= ~UCR1_UARTEN;

        /* Set to default POR state */

        base->ucr1 = 0x00000004;
        base->ucr2 = 0x00000000;
        base->ucr3 = 0x00000000;
        base->ucr4 = 0x00008040;
        base->uesc = 0x0000002B;
        base->utim = 0x00000000;
        base->ubir = 0x00000000;
        base->ubmr = 0x00000000;
        base->uts  = 0x00000000;
        /* Set clocks */
        base->ucr4 |= UCR4_REF16;

        /* Configure FIFOs */
        base->ufcr = 0xa81;

        /* set the baud rate.
         *
         * baud * 16   x
         * --------- = -
         *  refclk     y
         *
         * x - 1 = UBIR
         * y - 1 = UBMR
         *
         * each register is 16 bits wide. refclk max is 96 MHz
         *
         */

        ufcr_rfdiv = ((base->ufcr) & UFCR_RFDIV) >> 7;
        if (ufcr_rfdiv == 6)
                ufcr_rfdiv = 7;
        else
                ufcr_rfdiv = 6 - ufcr_rfdiv;

        refclk = get_PERCLK1();
        refclk /= ufcr_rfdiv;

        /* Set the numerator value minus one of the BRM ratio */
        base->ubir = (gd->baudrate / 100) - 1;

        /* Set the denominator value minus one of the BRM ratio */
        base->ubmr = (refclk/(16 * 100)) - 1;

        /* Set to 8N1 */
        base->ucr2 &= ~UCR2_PREN;
        base->ucr2 |= UCR2_WS;
        base->ucr2 &= ~UCR2_STPB;

        /* Ignore RTS */
        base->ucr2 |= UCR2_IRTS;

        /* Enable UART */
        base->ucr1 |= UCR1_UARTEN | UCR1_UARTCLKEN;

        /* Enable FIFOs */
        base->ucr2 |= UCR2_SRST | UCR2_RXEN | UCR2_TXEN;

        /* Clear status flags */
        base->usr2 |= USR2_ADET  |
                      USR2_DTRF  |
                      USR2_IDLE  |
                      USR2_IRINT |
                      USR2_WAKE  |
                      USR2_RTSF  |
                      USR2_BRCD  |
                      USR2_ORE;

        /* Clear status flags */
        base->usr1 |= USR1_PARITYERR |
                      USR1_RTSD      |
                      USR1_ESCF      |
                      USR1_FRAMERR   |
                      USR1_AIRINT    |
                      USR1_AWAKE;
        return (0);
}

/*
 * Read a single byte from the serial port. Returns 1 on success, 0
 * otherwise. When the function is successful, the character read is
 * written into its argument c.
 */
int serial_getc (void)
{
        volatile struct imx_serial* base = (struct imx_serial *)UART_BASE;
        unsigned char ch;

        while(base->uts & UTS_RXEMPTY);

        ch = (char)base->urxd[0];

        return ch;
}

#ifdef CONFIG_HWFLOW
static int hwflow = 0; /* turned off by default */
int hwflow_onoff(int on)
{
}
#endif

/*
 * Output a single byte to the serial port.
 */
void serial_putc (const char c)
{
        volatile struct imx_serial* base = (struct imx_serial *)UART_BASE;

        /* Wait for Tx FIFO not full */
        while (base->uts & UTS_TXFULL);

        base->utxd[0] = c;

        /* If \n, also do \r */
        if (c == '\n')
                serial_putc ('\r');
}

/*
 * Test whether a character is in the RX buffer
 */
int serial_tstc (void)
{
        volatile struct imx_serial* base = (struct imx_serial *)UART_BASE;

        /* If receive fifo is empty, return false */
        if (base->uts & UTS_RXEMPTY)
                return 0;
        return 1;
}

void
serial_puts (const char *s)
{
        while (*s) {
                serial_putc (*s++);
        }
}