freifunkist-firmware/target/linux/brcm-2.4/files/arch/mips/bcm947xx/hndchipc.c

/*
 * BCM47XX support code for some chipcommon (old extif) facilities (uart)
 *
 * Copyright 2006, Broadcom Corporation
 * All Rights Reserved.
 * 
 * THIS SOFTWARE IS OFFERED "AS IS", AND BROADCOM GRANTS NO WARRANTIES OF ANY
 * KIND, EXPRESS OR IMPLIED, BY STATUTE, COMMUNICATION OR OTHERWISE. BROADCOM
 * SPECIFICALLY DISCLAIMS ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS
 * FOR A SPECIFIC PURPOSE OR NONINFRINGEMENT CONCERNING THIS SOFTWARE.
 *
 * $Id: hndchipc.c,v 1.1.1.1 2006/02/27 03:43:16 honor Exp $
 */

#include <typedefs.h>
#include <bcmdefs.h>
#include <osl.h>
#include <bcmutils.h>
#include <sbutils.h>
#include <bcmdevs.h>
#include <bcmnvram.h>
#include <sbconfig.h>
#include <sbextif.h>
#include <sbchipc.h>
#include <hndcpu.h>

/*
 * Returns TRUE if an external UART exists at the given base
 * register.
 */
static bool
BCMINITFN(serial_exists)(osl_t *osh, uint8 *regs)
{
	uint8 save_mcr, status1;

	save_mcr = R_REG(osh, &regs[UART_MCR]);
	W_REG(osh, &regs[UART_MCR], UART_MCR_LOOP | 0x0a);
	status1 = R_REG(osh, &regs[UART_MSR]) & 0xf0;
	W_REG(osh, &regs[UART_MCR], save_mcr);

	return (status1 == 0x90);
}

/*
 * Initializes UART access. The callback function will be called once
 * per found UART.
 */
void
BCMINITFN(sb_serial_init)(sb_t *sbh, void (*add)(void *regs, uint irq, uint baud_base,
                                                 uint reg_shift))
{
	osl_t *osh;
	void *regs;
	ulong base;
	uint irq;
	int i, n;

	osh = sb_osh(sbh);

	if ((regs = sb_setcore(sbh, SB_EXTIF, 0))) {
		extifregs_t *eir = (extifregs_t *) regs;
		sbconfig_t *sb;

		/* Determine external UART register base */
		sb = (sbconfig_t *)((ulong) eir + SBCONFIGOFF);
		base = EXTIF_CFGIF_BASE(sb_base(R_REG(osh, &sb->sbadmatch1)));

		/* Determine IRQ */
		irq = sb_irq(sbh);

		/* Disable GPIO interrupt initially */
		W_REG(osh, &eir->gpiointpolarity, 0);
		W_REG(osh, &eir->gpiointmask, 0);

		/* Search for external UARTs */
		n = 2;
		for (i = 0; i < 2; i++) {
			regs = (void *) REG_MAP(base + (i * 8), 8);
			if (serial_exists(osh, regs)) {
				/* Set GPIO 1 to be the external UART IRQ */
				W_REG(osh, &eir->gpiointmask, 2);
				/* XXXDetermine external UART clock */
				if (add)
					add(regs, irq, 13500000, 0);
			}
		}

		/* Add internal UART if enabled */
		if (R_REG(osh, &eir->corecontrol) & CC_UE)
			if (add)
				add((void *) &eir->uartdata, irq, sb_clock(sbh), 2);
	} else if ((regs = sb_setcore(sbh, SB_CC, 0))) {
		chipcregs_t *cc = (chipcregs_t *) regs;
		uint32 rev, cap, pll, baud_base, div;

		/* Determine core revision and capabilities */
		rev = sb_corerev(sbh);
		cap = R_REG(osh, &cc->capabilities);
		pll = cap & CAP_PLL_MASK;

		/* Determine IRQ */
		irq = sb_irq(sbh);

		if (pll == PLL_TYPE1) {
			/* PLL clock */
			baud_base = sb_clock_rate(pll,
			                          R_REG(osh, &cc->clockcontrol_n),
			                          R_REG(osh, &cc->clockcontrol_m2));
			div = 1;
		} else {
			/* Fixed ALP clock */
			if (rev >= 11 && rev != 15) {
				baud_base = 20000000;
				div = 1;
				/* Set the override bit so we don't divide it */
				W_REG(osh, &cc->corecontrol, CC_UARTCLKO);
			}
			/* Internal backplane clock */
			else if (rev >= 3) {
				baud_base = sb_clock(sbh);
				div = 2;	/* Minimum divisor */
				W_REG(osh, &cc->clkdiv,
				      ((R_REG(osh, &cc->clkdiv) & ~CLKD_UART) | div));
			}
			/* Fixed internal backplane clock */
			else {
				baud_base = 88000000;
				div = 48;
			}

			/* Clock source depends on strapping if UartClkOverride is unset */
			if ((rev > 0) &&
			    ((R_REG(osh, &cc->corecontrol) & CC_UARTCLKO) == 0)) {
				if ((cap & CAP_UCLKSEL) == CAP_UINTCLK) {
					/* Internal divided backplane clock */
					baud_base /= div;
				} else {
					/* Assume external clock of 1.8432 MHz */
					baud_base = 1843200;
				}
			}
		}

		/* Add internal UARTs */
		n = cap & CAP_UARTS_MASK;
		for (i = 0; i < n; i++) {
			/* Register offset changed after revision 0 */
			if (rev)
				regs = (void *)((ulong) &cc->uart0data + (i * 256));
			else
				regs = (void *)((ulong) &cc->uart0data + (i * 8));

			if (add)
				add(regs, irq, baud_base, 0);
		}
	}
}