/*
   * CPM serial console support.
   *
   * Copyright 2007 Freescale Semiconductor, Inc.
   * Author: Scott Wood <scottwood@freescale.com>
   *
   * 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"
  #include "page.h"
  
  struct cpm_scc {
  	u32 gsmrl;
  	u32 gsmrh;
  	u16 psmr;
  	u8 res1[2];
  	u16 todr;
  	u16 dsr;
  	u16 scce;
  	u8 res2[2];
  	u16 sccm;
  	u8 res3;
  	u8 sccs;
  	u8 res4[8];
  };
  
  struct cpm_smc {
  	u8 res1[2];
  	u16 smcmr;
  	u8 res2[2];
  	u8 smce;
  	u8 res3[3];
  	u8 smcm;
  	u8 res4[5];
  };
  
  struct cpm_param {
  	u16 rbase;
  	u16 tbase;
  	u8 rfcr;
  	u8 tfcr;
  	u16 mrblr;
  	u32 rstate;
  	u8 res1[4];
  	u16 rbptr;
  	u8 res2[6];
  	u32 tstate;
  	u8 res3[4];
  	u16 tbptr;
  	u8 res4[6];
  	u16 maxidl;
  	u16 idlc;
  	u16 brkln;
  	u16 brkec;
  	u16 brkcr;
  	u16 rmask;
  	u8 res5[4];
  };
  
  struct cpm_bd {
  	u16 sc;   /* Status and Control */
  	u16 len;  /* Data length in buffer */
  	u8 *addr; /* Buffer address in host memory */
  };
  
  static void *cpcr;
  static struct cpm_param *param;
  static struct cpm_smc *smc;
  static struct cpm_scc *scc;
  static struct cpm_bd *tbdf, *rbdf;
  static u32 cpm_cmd;
  static void *cbd_addr;
  static u32 cbd_offset;
  
  static void (*do_cmd)(int op);
  static void (*enable_port)(void);
  static void (*disable_port)(void);
  
  #define CPM_CMD_STOP_TX     4
  #define CPM_CMD_RESTART_TX  6
  #define CPM_CMD_INIT_RX_TX  0
  
  static void cpm1_cmd(int op)
  {
  	while (in_be16(cpcr) & 1)
  		;
  
  	out_be16(cpcr, (op << 8) | cpm_cmd | 1);
  
  	while (in_be16(cpcr) & 1)
  		;
  }
  
  static void cpm2_cmd(int op)
  {
  	while (in_be32(cpcr) & 0x10000)
  		;
  
  	out_be32(cpcr, op | cpm_cmd | 0x10000);
  
  	while (in_be32(cpcr) & 0x10000)
  		;
  }
  
  static void smc_disable_port(void)
  {
  	do_cmd(CPM_CMD_STOP_TX);
  	out_be16(&smc->smcmr, in_be16(&smc->smcmr) & ~3);
  }
  
  static void scc_disable_port(void)
  {
  	do_cmd(CPM_CMD_STOP_TX);
  	out_be32(&scc->gsmrl, in_be32(&scc->gsmrl) & ~0x30);
  }
  
  static void smc_enable_port(void)
  {
  	out_be16(&smc->smcmr, in_be16(&smc->smcmr) | 3);
  	do_cmd(CPM_CMD_RESTART_TX);
  }
  
  static void scc_enable_port(void)
  {
  	out_be32(&scc->gsmrl, in_be32(&scc->gsmrl) | 0x30);
  	do_cmd(CPM_CMD_RESTART_TX);
  }
  
  static int cpm_serial_open(void)
  {
  	disable_port();
  
  	out_8(&param->rfcr, 0x10);
  	out_8(&param->tfcr, 0x10);
  	out_be16(&param->mrblr, 1);
  	out_be16(&param->maxidl, 0);
  	out_be16(&param->brkec, 0);
  	out_be16(&param->brkln, 0);
  	out_be16(&param->brkcr, 0);
  
  	rbdf = cbd_addr;
  	rbdf->addr = (u8 *)rbdf - 1;
  	rbdf->sc = 0xa000;
  	rbdf->len = 1;
  
  	tbdf = rbdf + 1;
  	tbdf->addr = (u8 *)rbdf - 2;
  	tbdf->sc = 0x2000;
  	tbdf->len = 1;
  
  	sync();
  	out_be16(&param->rbase, cbd_offset);
  	out_be16(&param->tbase, cbd_offset + sizeof(struct cpm_bd));
  
  	do_cmd(CPM_CMD_INIT_RX_TX);
  
  	enable_port();
  	return 0;
  }
  
  static void cpm_serial_putc(unsigned char c)
  {
  	while (tbdf->sc & 0x8000)
  		barrier();
  
  	sync();
  
  	tbdf->addr[0] = c;
  	eieio();
  	tbdf->sc |= 0x8000;
  }
  
  static unsigned char cpm_serial_tstc(void)
  {
  	barrier();
  	return !(rbdf->sc & 0x8000);
  }
  
  static unsigned char cpm_serial_getc(void)
  {
  	unsigned char c;
  
  	while (!cpm_serial_tstc())
  		;
  
  	sync();
  	c = rbdf->addr[0];
  	eieio();
  	rbdf->sc |= 0x8000;
  
  	return c;
  }
  
  int cpm_console_init(void *devp, struct serial_console_data *scdp)
  {
  	void *vreg[2];
  	u32 reg[2];
  	int is_smc = 0, is_cpm2 = 0;
  	void *parent, *muram;
  	void *muram_addr;
  	unsigned long muram_offset, muram_size;
  
  	if (dt_is_compatible(devp, "fsl,cpm1-smc-uart")) {
  		is_smc = 1;
  	} else if (dt_is_compatible(devp, "fsl,cpm2-scc-uart")) {
  		is_cpm2 = 1;
  	} else if (dt_is_compatible(devp, "fsl,cpm2-smc-uart")) {
  		is_cpm2 = 1;
  		is_smc = 1;
  	}
  
  	if (is_smc) {
  		enable_port = smc_enable_port;
  		disable_port = smc_disable_port;
  	} else {
  		enable_port = scc_enable_port;
  		disable_port = scc_disable_port;
  	}
  
  	if (is_cpm2)
  		do_cmd = cpm2_cmd;
  	else
  		do_cmd = cpm1_cmd;
  
  	if (getprop(devp, "fsl,cpm-command", &cpm_cmd, 4) < 4)
  		return -1;
  
  	if (dt_get_virtual_reg(devp, vreg, 2) < 2)
  		return -1;
  
  	if (is_smc)
  		smc = vreg[0];
  	else
  		scc = vreg[0];
  
  	param = vreg[1];
  
  	parent = get_parent(devp);
  	if (!parent)
  		return -1;
  
  	if (dt_get_virtual_reg(parent, &cpcr, 1) < 1)
  		return -1;
  
  	muram = finddevice("/soc/cpm/muram/data");
  	if (!muram)
  		return -1;
  
  	/* For bootwrapper-compatible device trees, we assume that the first
  	 * entry has at least 128 bytes, and that #address-cells/#data-cells
  	 * is one for both parent and child.
  	 */
  
  	if (dt_get_virtual_reg(muram, &muram_addr, 1) < 1)
  		return -1;
  
  	if (getprop(muram, "reg", reg, 8) < 8)
  		return -1;
  
  	muram_offset = reg[0];
  	muram_size = reg[1];
  
  	/* Store the buffer descriptors at the end of the first muram chunk.
  	 * For SMC ports on CPM2-based platforms, relocate the parameter RAM
  	 * just before the buffer descriptors.
  	 */
  
  	cbd_offset = muram_offset + muram_size - 2 * sizeof(struct cpm_bd);
  
  	if (is_cpm2 && is_smc) {
  		u16 *smc_base = (u16 *)param;
  		u16 pram_offset;
  
  		pram_offset = cbd_offset - 64;
  		pram_offset = _ALIGN_DOWN(pram_offset, 64);
  
  		disable_port();
  		out_be16(smc_base, pram_offset);
  		param = muram_addr - muram_offset + pram_offset;
  	}
  
  	cbd_addr = muram_addr - muram_offset + cbd_offset;
  
  	scdp->open = cpm_serial_open;
  	scdp->putc = cpm_serial_putc;
  	scdp->getc = cpm_serial_getc;
  	scdp->tstc = cpm_serial_tstc;
  
  	return 0;
  }