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kernel/linux-imx6_3.14.28/arch/powerpc/boot/mpc52xx-psc.c 1.43 KB
6b13f685e   김민수   BSP 최초 추가
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  /*
   * MPC5200 PSC serial console support.
   *
   * Author: Grant Likely <grant.likely@secretlab.ca>
   *
   * Copyright (c) 2007 Secret Lab Technologies Ltd.
   * Copyright (c) 2007 Freescale Semiconductor, Inc.
   *
   * It is assumed that the firmware (or the platform file) has already set
   * up the port.
   */
  
  #include "types.h"
  #include "io.h"
  #include "ops.h"
  
  /* Programmable Serial Controller (PSC) status register bits */
  #define MPC52xx_PSC_SR		0x04
  #define MPC52xx_PSC_SR_RXRDY		0x0100
  #define MPC52xx_PSC_SR_RXFULL		0x0200
  #define MPC52xx_PSC_SR_TXRDY		0x0400
  #define MPC52xx_PSC_SR_TXEMP		0x0800
  
  #define MPC52xx_PSC_BUFFER	0x0C
  
  static void *psc;
  
  static int psc_open(void)
  {
  	/* Assume the firmware has already configured the PSC into
  	 * uart mode */
  	return 0;
  }
  
  static void psc_putc(unsigned char c)
  {
  	while (!(in_be16(psc + MPC52xx_PSC_SR) & MPC52xx_PSC_SR_TXRDY)) ;
  	out_8(psc + MPC52xx_PSC_BUFFER, c);
  }
  
  static unsigned char psc_tstc(void)
  {
  	return (in_be16(psc + MPC52xx_PSC_SR) & MPC52xx_PSC_SR_RXRDY) != 0;
  }
  
  static unsigned char psc_getc(void)
  {
  	while (!(in_be16(psc + MPC52xx_PSC_SR) & MPC52xx_PSC_SR_RXRDY)) ;
  	return in_8(psc + MPC52xx_PSC_BUFFER);
  }
  
  int mpc5200_psc_console_init(void *devp, struct serial_console_data *scdp)
  {
  	/* Get the base address of the psc registers */
  	if (dt_get_virtual_reg(devp, &psc, 1) < 1)
  		return -1;
  
  	scdp->open = psc_open;
  	scdp->putc = psc_putc;
  	scdp->getc = psc_getc;
  	scdp->tstc = psc_tstc;
  
  	return 0;
  }