[Gc-linux-cvs] linux/arch/powerpc/platforms/embedded6xx usbgecko_udbg.c, NONE, 1.1

[Albert H. <he...@us...>]

Update of /cvsroot/gc-linux/linux/arch/powerpc/platforms/embedded6xx
In directory sc8-pr-cvs2.sourceforge.net:/tmp/cvs-serv28622/arch/powerpc/platforms/embedded6xx

Added Files:
	usbgecko_udbg.c 
Log Message:
Added USB Gecko based udbg console, suitable for early debug too.


--- NEW FILE: usbgecko_udbg.c ---
/*
 * arch/powerpc/platforms/embedded6xx/usbgecko_udbg.c
 *
 * udbg serial input/output routines for the USB Gecko adapter.
 * Copyright (C) 2008 The GameCube Linux Team
 * Copyright (C) 2008 Albert Herranz
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 */

#include <asm/io.h>
#include <asm/prom.h>
#include <asm/udbg.h>

#include <mm/mmu_decl.h>

#include "usbgecko_udbg.h"


#define EXI_CLK_32MHZ           5

#define EXI_CSR                 0x00
#define   EXI_CSR_CLKMASK       (0x7<<4)
#define     EXI_CSR_CLK_32MHZ   (EXI_CLK_32MHZ<<4)
#define   EXI_CSR_CSMASK        (0x7<<7)
#define     EXI_CSR_CS_0        (0x1<<7)  /* Chip Select 001 */

#define EXI_CR                  0x0c
#define   EXI_CR_TSTART         (1<<0)
#define   EXI_CR_WRITE		(1<<2)
#define   EXI_CR_READ_WRITE     (2<<2)
#define   EXI_CR_TLEN(len)      (((len)-1)<<4)

#define EXI_DATA                0x10


static void __iomem *ug_io_base;

/*
 * Performs one input/output transaction between the spi host and the usbgecko.
 */
static u32 ug_io_transaction(u32 in)
{
        u32 __iomem *csr_reg = ug_io_base + EXI_CSR;
        u32 __iomem *data_reg = ug_io_base + EXI_DATA;
        u32 __iomem *cr_reg = ug_io_base + EXI_CR;
        u32 csr, data, cr;

        /* select */
        csr = EXI_CSR_CLK_32MHZ | EXI_CSR_CS_0;
        out_be32(csr_reg, csr);

        /* read/write */
        data = in;
        out_be32(data_reg, data);
        cr = EXI_CR_TLEN(2) | EXI_CR_READ_WRITE | EXI_CR_TSTART;
        out_be32(cr_reg, cr);

        while(in_be32(cr_reg) & EXI_CR_TSTART)
                barrier();

        /* deselect */
        out_be32(csr_reg, 0);

	/* result */
        data = in_be32(data_reg);

	return data;
}

/*
 * Returns true if an usbgecko adapter is found.
 */
static int ug_is_adapter_present(void)
{
	if (!ug_io_base)
		return 0;

	return (ug_io_transaction(0x90000000) == 0x04700000);
}

/*
 * Returns true if the TX fifo is ready for transmission.
 */
static int ug_is_txfifo_ready(void)
{
	return (ug_io_transaction(0xc0000000) & 0x04000000);
}

/*
 * Tries to transmit a character.
 * If the TX fifo is not ready the result is undefined.
 */
static void ug_raw_putc(char ch)
{
	ug_io_transaction(0xb0000000 | (ch << 20));
}

/*
 * Transmits a character.
 * It silently fails if the TX fifo is not ready after a number of retries.
 */
static void ug_putc(char ch)
{
	int count = 16;

	if (!ug_io_base)
		return;

	if (ch == '\n')
		ug_putc('\r');

        while(!ug_is_txfifo_ready() && count--) 
                barrier();
	if (count)
	        ug_raw_putc(ch);
}

#if 0
/*
 * Trasmits a null terminated character string.
 */
static void ug_puts(char *s)
{
	while(*s)
		ug_putc(*s++);
}
#endif

/*
 * Returns true if the RX fifo is ready for transmission.
 */
static int ug_is_rxfifo_ready(void)
{
	return (ug_io_transaction(0xd0000000) & 0x04000000);
}

/*
 * Tries to receive a character.
 * If a character is unavailable the function returns -1.
 */
static int ug_raw_getc(void)
{
	u32 data = ug_io_transaction(0xa0000000);
	if (data & 0x08000000)
		return (data >> 16) & 0xff;
	else
		return -1;
}

/*
 * Receives a character.
 * It fails if the RX fifo is not ready after a number of retries.
 */
static int ug_getc(void)
{
	int count = 16;

	if (!ug_io_base)
		return -1;

        while(!ug_is_rxfifo_ready() && count--) 
                barrier();
        return ug_raw_getc();
}

/*
 * udbg functions.
 *
 */

/*
 * Transmits a character.
 */
static void ug_udbg_putc(char ch)
{
	ug_putc(ch);
}

/*
 * Receives a character. Waits until a character is available.
 */
static int ug_udbg_getc(void)
{
	int ch;

	while((ch = ug_getc()) == -1)
		barrier();
	return ch;
}

/*
 * Receives a character. If a character is not available, returns -1.
 */
static int ug_udbg_getc_poll(void)
{
	if (!ug_is_rxfifo_ready())
		return -1;
        return ug_getc();
}

/*
 * Retrieves and prepares the virtual address needed to access the hardware.
 */
static void __iomem *ug_udbg_setup_io_base(struct device_node *np)
{
	phys_addr_t paddr;
	const unsigned int *reg;

	reg = of_get_property(np, "reg", NULL);
	if (reg) {
		paddr = of_translate_address(np, reg);
		if (paddr)
			ug_io_base = ioremap(paddr, reg[1]);
	}
	return ug_io_base;
}

/*
 * USB Gecko udbg support initialization.
 */
void __init ug_udbg_init(void)
{
	struct device_node *np;
	struct device_node *stdout;
	const char *path;

	ug_io_base = NULL;

	path = of_get_property(of_chosen, "linux,stdout-path", NULL);
	if (!path)
		return;

	stdout = of_find_node_by_path(path);
	if (!stdout)
		return;

	for(np = NULL;
	    (np = of_find_compatible_node(np, NULL, "usbgecko,usbgecko")); )
		if (np == stdout)
			break;

	of_node_put(stdout);
	if (!np)
		return;

	ug_udbg_setup_io_base(np);
	if (ug_is_adapter_present()) {
		udbg_putc = ug_udbg_putc;
		udbg_getc = ug_udbg_getc;
		udbg_getc_poll = ug_udbg_getc_poll;
	}

	of_node_put(np);
}

#ifdef CONFIG_PPC_EARLY_DEBUG_USBGECKO

/*
 * USB Gecko early udbg support initialization.
 * The USB Gecko must be inserted in memcard slot B for early debugging.
 *
 */
void __init udbg_init_debug_usbgecko(void)
{
	unsigned long vaddr, paddr;

#if defined(CONFIG_GAMECUBE)
	paddr = 0x0c000000;
#elif defined(CONFIG_WII)
	paddr = 0x0d000000;
#else
#error Invalid platform for USB Gecko based early debugging.
#endif

	vaddr = 0xc0000000 | paddr;
	setbat(1, vaddr, paddr, 128*1024, _PAGE_IO);

	ug_io_base = (void __iomem *)(vaddr | 0x6814);

	udbg_putc = ug_udbg_putc;
	udbg_getc = ug_udbg_getc;
	udbg_getc_poll = ug_udbg_getc_poll;
}

#endif /* CONFIG_PPC_EARLY_DEBUG_USBGECKO */