LXR linux/arch/powerpc/boot/mpc52xx-psc.c

   1/*
   2 * MPC5200 PSC serial console support.
   3 *
   4 * Author: Grant Likely <grant.likely@secretlab.ca>
   5 *
   6 * Copyright (c) 2007 Secret Lab Technologies Ltd.
   7 * Copyright (c) 2007 Freescale Semiconductor, Inc.
   8 *
   9 * It is assumed that the firmware (or the platform file) has already set
  10 * up the port.
  11 */
  12
  13#include "types.h"
  14#include "io.h"
  15#include "ops.h"
  16
  17/* Programmable Serial Controller (PSC) status register bits */
  18#define MPC52xx_PSC_SR          0x04
  19#define MPC52xx_PSC_SR_RXRDY            0x0100
  20#define MPC52xx_PSC_SR_RXFULL           0x0200
  21#define MPC52xx_PSC_SR_TXRDY            0x0400
  22#define MPC52xx_PSC_SR_TXEMP            0x0800
  23
  24#define MPC52xx_PSC_BUFFER      0x0C
  25
  26static void *psc;
  27
  28static int psc_open(void)
  29{
  30        /* Assume the firmware has already configured the PSC into
  31         * uart mode */
  32        return 0;
  33}
  34
  35static void psc_putc(unsigned char c)
  36{
  37        while (!(in_be16(psc + MPC52xx_PSC_SR) & MPC52xx_PSC_SR_TXRDY)) ;
  38        out_8(psc + MPC52xx_PSC_BUFFER, c);
  39}
  40
  41static unsigned char psc_tstc(void)
  42{
  43        return (in_be16(psc + MPC52xx_PSC_SR) & MPC52xx_PSC_SR_RXRDY) != 0;
  44}
  45
  46static unsigned char psc_getc(void)
  47{
  48        while (!(in_be16(psc + MPC52xx_PSC_SR) & MPC52xx_PSC_SR_RXRDY)) ;
  49        return in_8(psc + MPC52xx_PSC_BUFFER);
  50}
  51
  52int mpc5200_psc_console_init(void *devp, struct serial_console_data *scdp)
  53{
  54        /* Get the base address of the psc registers */
  55        if (dt_get_virtual_reg(devp, &psc, 1) < 1)
  56                return -1;
  57
  58        scdp->open = psc_open;
  59        scdp->putc = psc_putc;
  60        scdp->getc = psc_getc;
  61        scdp->tstc = psc_tstc;
  62
  63        return 0;
  64}
  65