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/*

 * UART driver used by OMAP devices

 *

 * Copyright (C) 2007 Bahadir Balban

 */

#include <l4/drivers/uart/omap/uart.h>

#include INC_ARCH(io.h)

#define OMAP_UART_FIFO_ENABLE   (1 << 0)

#define OMAP_UART_RX_FIFO_CLR   (1 << 1)

#define OMAP_UART_TX_FIFO_CLR   (1 << 2)

static inline void uart_enable_fifo(unsigned long uart_base)

{

        volatile u32 reg = read(uart_base + OMAP_UART_FCR);

        reg |= (OMAP_UART_FIFO_ENABLE | OMAP_UART_RX_FIFO_CLR |

                OMAP_UART_TX_FIFO_CLR);

        write(reg, uart_base + OMAP_UART_FCR);

}

static inline void uart_disable_fifo(unsigned long uart_base)

{

        volatile u32 reg = read(uart_base + OMAP_UART_FCR);

        reg &= (~OMAP_UART_FIFO_ENABLE | OMAP_UART_RX_FIFO_CLR |

                OMAP_UART_TX_FIFO_CLR);

        write(reg, uart_base + OMAP_UART_FCR);

}

#define OMAP_UART_TX_ENABLE     (1 << 0)

static inline void uart_enable_tx(unsigned long uart_base)

{

        volatile u32 reg = read(uart_base + OMAP_UART_MCR);

        reg |= OMAP_UART_TX_ENABLE;

        write(reg, uart_base + OMAP_UART_MCR);

}

static inline void uart_disable_tx(unsigned long uart_base)

{

        volatile u32 reg = read(uart_base + OMAP_UART_MCR);

        reg &= ~OMAP_UART_TX_ENABLE;

        write(reg, uart_base + OMAP_UART_MCR);

}

#define OMAP_UART_RX_ENABLE     (1 << 1)

static inline void uart_enable_rx(unsigned long uart_base)

{

        volatile u32 reg = read(uart_base + OMAP_UART_MCR);

        reg |= OMAP_UART_RX_ENABLE;

        write(reg, uart_base + OMAP_UART_MCR);

}

static inline void uart_disable_rx(unsigned long uart_base)

{

        volatile u32 reg = read(uart_base + OMAP_UART_MCR);

        reg &= ~OMAP_UART_RX_ENABLE;

        write(reg, uart_base + OMAP_UART_MCR);

}

#define OMAP_UART_STOP_BITS_MASK        (1 << 2)

static inline void uart_set_stop_bits(unsigned long uart_base, int bits)

{

        volatile u32 reg = read(uart_base + OMAP_UART_LCR);

        reg &= ~OMAP_UART_STOP_BITS_MASK;

        reg |= (bits << 2);

        write(reg, uart_base + OMAP_UART_LCR);

}

#define OMAP_UART_DATA_BITS_MASK        (0x3)

static inline void uart_set_data_bits(unsigned long uart_base, int bits)

{

        volatile u32 reg = read(uart_base + OMAP_UART_LCR);

        reg &= ~OMAP_UART_DATA_BITS_MASK;

        reg |= bits;

        write(reg, uart_base + OMAP_UART_LCR);

}

#define OMAP_UART_PARITY_ENABLE         (1 << 3)

static inline void uart_enable_parity(unsigned long uart_base)

{

        volatile u32 reg = read(uart_base + OMAP_UART_LCR);

        reg |= OMAP_UART_PARITY_ENABLE;

        write(reg, uart_base + OMAP_UART_LCR);

}

static inline void uart_disable_parity(unsigned long uart_base)

{

        volatile u32 reg = read(uart_base + OMAP_UART_LCR);

        reg &= ~OMAP_UART_PARITY_ENABLE;

        write(reg, uart_base + OMAP_UART_LCR);

}

#define OMAP_UART_PARITY_EVEN           (1 << 4)

static inline void uart_set_even_parity(unsigned long uart_base)

{

        volatile u32 reg = read(uart_base + OMAP_UART_LCR);

        reg |= OMAP_UART_PARITY_EVEN;

        write(reg, uart_base + OMAP_UART_LCR);

}

static inline void uart_set_odd_parity(unsigned long uart_base)

{

        volatile u32 reg = read(uart_base + OMAP_UART_LCR);

        reg &= ~OMAP_UART_PARITY_EVEN;

        write(reg, uart_base + OMAP_UART_LCR);

}

static inline void uart_select_mode(unsigned long uart_base, int mode)

{

        write(mode, uart_base + OMAP_UART_MDR1);

}

#define OMAP_UART_INTR_EN       1

static inline void uart_enable_interrupt(unsigned long uart_base)

{

        write(OMAP_UART_INTR_EN, uart_base + OMAP_UART_IER);

}

static inline void uart_disable_interrupt(unsigned long uart_base)

{

        write((~OMAP_UART_INTR_EN), uart_base + OMAP_UART_IER);

}

static inline void uart_set_link_control(unsigned long uart_base, int mode)

{

        write(mode, uart_base + OMAP_UART_LCR);

}

#define OMAP_UART_TXFE          0x20

void uart_tx_char(unsigned long uart_base, char c)

{

        volatile u32 reg;

        /* Check if there is space for tx */

        do {

                reg = read(uart_base + OMAP_UART_LSR);

        } while(!(reg & OMAP_UART_TXFE));

        write(c, uart_base + OMAP_UART_THR);

}

#define OMAP_UART_RXFNE                 0x1

#define OMAP_UART_RX_FIFO_STATUS        0x8

char uart_rx_char(unsigned long uart_base)

{

        volatile u32 reg;

        /* Check if pending data is there */

        do {

                reg = read(uart_base + OMAP_UART_LSR);

        } while(!(reg & OMAP_UART_RXFNE));

#if 0

        /* Check if there is some error in recieve */

        if(reg & OMAP_UART_RX_FIFO_STATUS)

                return -1;

#endif

        return (char)read(uart_base + OMAP_UART_RHR);

}

void uart_set_baudrate(unsigned long uart_base, u32 baudrate, u32 clkrate)

{

        u32 clk_div = 0;

        /* 48Mhz clock fixed on beagleboard */

        const u32 uartclk = 48000000;

        if(clkrate == 0)

                clkrate = uartclk;

        /* If baud out of range, set default rate */

        if(baudrate > 3686400 || baudrate < 300)

                baudrate = 115200;

        clk_div = clkrate/(16 * baudrate);

        /* Set clockrate in DLH and DLL */

        write((clk_div & 0xff), uart_base + OMAP_UART_DLL);

        write(((clk_div >> 8) & 0xff ), uart_base + OMAP_UART_DLH);

}

void uart_init(unsigned long uart_base)

{

        /* Disable UART */

        uart_select_mode(uart_base, OMAP_UART_MODE_DEFAULT);

        /* Disable interrupts */

        uart_disable_interrupt(uart_base);

        /* Change to config mode, to set baud divisor */

        uart_set_link_control(uart_base, OMAP_UART_BANKED_MODE_CONFIG_A);

        /* Set the baud rate */

        uart_set_baudrate(uart_base, 115200, 48000000);

        /* Switch to operational mode */

        uart_set_link_control(uart_base, OMAP_UART_BANKED_MODE_OPERATIONAL);

        /* Set up the link- parity, data bits stop bits to 8N1 */

        uart_disable_parity(uart_base);

        uart_set_data_bits(uart_base, OMAP_UART_DATA_BITS_8);

        uart_set_stop_bits(uart_base, OMAP_UART_STOP_BITS_1);

        /* Disable Fifos */

        uart_disable_fifo(uart_base);

        /* Enable modem Rx/Tx */

        uart_enable_tx(uart_base);

        uart_enable_rx(uart_base);

        /* Enable UART in 16x mode */

        uart_select_mode(uart_base, OMAP_UART_MODE_UART16X);

}