FreeBSD/Linux Kernel Cross Reference
sys/arm/freescale/imx/imx_console.c

     /*-
      * Copyright (c) 2012, 2013 The FreeBSD Foundation
      * All rights reserved.
      *
      * This software was developed by Oleksandr Rybalko under sponsorship
      * from the FreeBSD Foundation.
      *
      * Redistribution and use in source and binary forms, with or without
      * modification, are permitted provided that the following conditions
     * are met:
     * 1.   Redistributions of source code must retain the above copyright
     *      notice, this list of conditions and the following disclaimer.
     * 2.   Redistributions in binary form must reproduce the above copyright
     *      notice, this list of conditions and the following disclaimer in the
     *      documentation and/or other materials provided with the distribution.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     * SUCH DAMAGE.
     */
    
    /* Simple UART console driver for Freescale i.MX515 */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    
    #include <sys/types.h>
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/cons.h>
    #include <sys/consio.h>
    #include <sys/kernel.h>
    
    /* Allow it to be predefined, to be able to use another UART for console */
    #ifndef IMX_UART_BASE
    #define IMX_UART_BASE   0xe3fbc000 /* imx51 UART1 */
    #endif
    
    #define IMX_RXD                 0x00
    #define IMX_TXD                 0x40
    
    #define IMX_UFCR                0x90
    #define IMX_USR1                0x94
    #define IMX_USR1_TRDY           (1 << 13)
    
    #define IMX_USR2                0x98
    #define IMX_USR2_RDR            (1 << 0)
    #define IMX_USR2_TXFE           (1 << 14)
    #define IMX_USR2_TXDC           (1 << 3)
    
    #define IMX_UTS                 0xb4
    #define IMX_UTS_TXFULL          (1 << 4)
    
    /*
     * The base address of the uart registers.
     *
     * This is global so that it can be changed on the fly from the outside.  For
     * example, set imx_uart_base=physaddr and then call cninit() as the first two
     * lines of initarm() and enjoy printf() availability through the tricky bits of
     * startup.  After initarm() switches from physical to virtual addressing, just
     * set imx_uart_base=virtaddr and printf keeps working.
     */
    uint32_t imx_uart_base = IMX_UART_BASE;
    
    /*
     * uart related funcs
     */
    static uint32_t
    ub_getreg(uint32_t off)
    {
    
            return *((volatile uint32_t *)(imx_uart_base + off));
    }
    
    static void
    ub_setreg(uint32_t off, uint32_t val)
    {
    
            *((volatile uint32_t *)(imx_uart_base + off)) = val;
    }
    
    static int
    ub_tstc(void)
    {
    
            return ((ub_getreg(IMX_USR2) & IMX_USR2_RDR) ? 1 : 0);
    }
    
    static int
    ub_getc(void)
    {
   
           while (!ub_tstc());
                   __asm __volatile("nop");
   
           return (ub_getreg(IMX_RXD) & 0xff);
   }
   
   static void
   ub_putc(unsigned char c)
   {
   
           if (c == '\n')
                   ub_putc('\r');
   
           while (ub_getreg(IMX_UTS) & IMX_UTS_TXFULL)
                   __asm __volatile("nop");
   
           ub_setreg(IMX_TXD, c);
   }
   
   static cn_probe_t       uart_cnprobe;
   static cn_init_t        uart_cninit;
   static cn_term_t        uart_cnterm;
   static cn_getc_t        uart_cngetc;
   static cn_putc_t        uart_cnputc;
   static cn_grab_t        uart_cngrab;
   static cn_ungrab_t      uart_cnungrab;
   
   static void
   uart_cngrab(struct consdev *cp)
   {
   
   }
   
   static void
   uart_cnungrab(struct consdev *cp)
   {
   
   }
   
   
   static void
   uart_cnprobe(struct consdev *cp)
   {
   
           sprintf(cp->cn_name, "uart");
           cp->cn_pri = CN_NORMAL;
   }
   
   static void
   uart_cninit(struct consdev *cp)
   {
   
           /* Init fifo trigger levels to 32 bytes, refclock div to 2. */
           ub_setreg(IMX_UFCR, 0x00004210);
   }
   
   static void
   uart_cnputc(struct consdev *cp, int c)
   {
   
           ub_putc(c);
   }
   
   static int
   uart_cngetc(struct consdev * cp)
   {
   
           return ub_getc();
   }
   
   static void
   uart_cnterm(struct consdev * cp)
   {
   
   }
   
   CONSOLE_DRIVER(uart);

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