ssp.c

一个2.4.21版本的嵌入式linux内核

			iRet = SSP_Write_I2SCodec( Handle, Addr, Value );
			break;
		}
		case SERIAL_FLASH:
		{
			break;
		}
		default:
		{
			return(-1);
		}
	}

	return iRet;
}

static void SetSSPtoPS2(void)
{
	unsigned int uiRegTemp;
	
	if( gSSPmode == SSP_MODE_PS2 )
	{
		return;
	}

	/*
	 * Disable the SSP, disable interrupts
	 */
	outl( 0, SSPCR1 );

	/*
	 * It takes almost a millisecond for a key to come in so
	 * make sure we have completed all transactions.
	 */
	mdelay(1);

	//
	// Set EGPIO7 to disable EEPROM device on EDB9301, EDB9302, EDB9307,
	// EDB9312, and EDB9315.
	//
	uiRegTemp = inl(GPIO_PADDR);
	outl( uiRegTemp | 0x80, GPIO_PADDR );

	uiRegTemp = inl(GPIO_PADR);
	outl( uiRegTemp | 0x80, GPIO_PADR );

    /*
     * Disable SFRM1 to I2S codec by setting EGPIO8 (port B, bit 0).
     * The EDB9307 and EDB9315 boards need this.
     */
#if defined(CONFIG_ARCH_EDB9307) || defined(CONFIG_ARCH_EDB9315)
    uiRegTemp = inl(GPIO_PBDDR) | 0x01;
    outl( uiRegTemp, GPIO_PBDDR );

    uiRegTemp = inl(GPIO_PBDR) | 0x01;
    outl( uiRegTemp, GPIO_PBDR );
	
	uiRegTemp = inl(GPIO_PBDR);
#endif

    /*
     * Disable SFRM1 to I2S codec I2S by setting EGPIO6 (port A, bit 6).
     * The EDB9301 and EDB9302 boards need this.
     */
#if defined(CONFIG_ARCH_EDB9301) || defined(CONFIG_ARCH_EDB9302)
	uiRegTemp = inl(GPIO_PADDR);
	outl( uiRegTemp | 0x40, GPIO_PADDR );

	uiRegTemp = inl(GPIO_PADR);
	outl( uiRegTemp | 0x40, GPIO_PADR );

	uiRegTemp = inl(GPIO_PADR);
#endif

	/*
	 * Still haven't enabled the keyboard.  So anything in
	 * the rx fifo is garbage.  Time to take out the trash.
	 */
	while( inl(SSPSR) & SSPSR_RNE )
	{
		uiRegTemp = inl(SSPDR);
	}

	/*
	 * SPICR0_SPO - SCLKOUT Polarity
	 * SPICR0_SPH - SCLKOUT Phase
	 * Motorola format, 11 bit, one start, 8 data, one bit for
	 * parity, one stop bit.
	 */
	outl( (SSPCR0_FRF_MOTOROLA | SSPCR0_SPH | SSPCR0_SPO | SSPCR0_DSS_11BIT),
	      SSPCR0 );
	/*
	 * Configure the device as a slave, Clear FIFO overrun interrupts,
	 * enable interrupts and reset the device.
	 */
	outl( (SSPC1_MS | SSPC1_RIE | SSPC1_SOD), SSPCR1 );
	outl( 0, SSPIIR );
	outl( (SSPC1_MS | SSPC1_RIE | SSPC1_SOD | SSPC1_SSE), SSPCR1 );

	/*
	 * Configure EGPIO pins 12 and 14 as outputs because they are used
	 * as buffer enables for the SPI interface to the ps2 keyboard.
	 * Clear EGPIO pins 12 and 14, this will enable the SPI keyboard.
	 */
	uiRegTemp = inl(GPIO_PBDDR);
	outl( uiRegTemp | 0x50, GPIO_PBDDR );

	uiRegTemp = inl(GPIO_PBDR);
	outl( uiRegTemp & ~0x50, GPIO_PBDR );

	gSSPmode = SSP_MODE_PS2;
}

static void SetSSPtoI2S(void)
{
	unsigned int uiRegTemp;

	if( gSSPmode == SSP_MODE_I2S )
	{
		return;
	}
	
	/*
	 * Disable recieve interrupts.
	 */
	outl( (SSPC1_MS | SSPC1_SSE), SSPCR1 );

	/*
	 * Set GPIO pins 12 and 14, this will bring the clock line low
	 * which signals to the keyboard to buffer keystrokes.
	 * Note that EGPIO 14 is the clock line and EGPIO 12 is data line.
	 */
	uiRegTemp = inl(GPIO_PBDR);
	outl( 0x50 | uiRegTemp, GPIO_PBDR );

	/*
	 * It takes almost a millisecond for an partial keystrokes to come in.
	 * Delay to make sure we have completed all transactions.
	 */
	mdelay(1);

	/*
	 * Anything we just recieved is garbage.  Time to take out the trash.
	 */
	while( inl(SSPSR) & SSPSR_RNE )
	{
		uiRegTemp = inl(SSPDR);
	}
	
	/*
	 * Disable the SSP and disable interrupts
	 */
	outl( 0, SSPCR1 );

	/*
	 * Clock will be 14.7 MHz divided by 4.
	 */
	outl( 2, SSPCPSR );

	/*
	 * Configure EGPIO7 as an output and set it.  This selects
	 * I2S codec as the device on the SSP output instead of
	 * the serial flash on EDB9312.  On EDB9301, EDB9302, EDB9307, and
	 * EDB9315 it disables EEPROM but doesn't select anything.
	 */
	uiRegTemp = inl(GPIO_PADDR);
	outl( uiRegTemp | 0x80, GPIO_PADDR );

	uiRegTemp = inl(GPIO_PADR);
	outl( uiRegTemp | 0x80, GPIO_PADR );

    /*
     * Enable SFRM1 to I2S codec by clearing EGPIO8 (port B, bit 0).
     * The EDB9307 and EDB9315 boards need this.
     */
#if defined(CONFIG_ARCH_EDB9307) || defined(CONFIG_ARCH_EDB9315)
    uiRegTemp = inl(GPIO_PBDDR) | 0x01;
    outl( uiRegTemp, GPIO_PBDDR );

    uiRegTemp = inl(GPIO_PBDR) & 0xfe;
    outl( uiRegTemp, GPIO_PBDR );
	
	uiRegTemp = inl(GPIO_PBDR);
#endif

    /*
     * Enable SFRM1 to I2S codec I2S by clearing EGPIO6 (port A, bit 6).
     * The EDB9301 and EDB9302 boards need this.
     */
#if defined(CONFIG_ARCH_EDB9301) || defined(CONFIG_ARCH_EDB9302)
	uiRegTemp = inl(GPIO_PADDR);
	outl( uiRegTemp | 0x40, GPIO_PADDR );

	uiRegTemp = inl(GPIO_PADR);
	outl( uiRegTemp & ~0x40, GPIO_PADR );

	uiRegTemp = inl(GPIO_PADR);
#endif

	/*
	 * Motorola format, 8 bit.
	 */
	outl( (SSPCR0_SPO | SSPCR0_SPH | SSPCR0_FRF_MOTOROLA | SSPCR0_DSS_8BIT),
	      SSPCR0 );

	/*
	 * Configure the device as master, reenable the device.
	 */
	outl( SSPC1_SSE, SSPCR1 );

	gSSPmode = SSP_MODE_I2S;

	udelay(10);
}

static void SetSSPtoFLASH(void)
{
	unsigned int uiRegTemp;

	if( gSSPmode == SSP_MODE_FLASH)
		return;

	/*
	 * Disable recieve interrupts.
	 */
	outl( (SSPC1_MS | SSPC1_SSE), SSPCR1 );

	/*
	 * Set GPIO pins 12 and 14, this will bring the clock line low
	 * which signals to the keyboard to buffer keystrokes.
	 * Note that EGPIO 14 is the clock line and EGPIO 12 is data line.
	 */
	outl( inl(GPIO_PBDR) | 0x50, GPIO_PBDR );

	/*
	 * It takes almost a millisecond for an partial keystrokes to come in.
	 * Delay to make sure we have completed all transactions.
	 */
	mdelay(1);

	/*
	 * Anything we just recieved is garbage.  Time to take out the trash.
	 */
	while( inl(SSPSR) & SSPSR_RNE )
		inl(SSPDR);
	
	/*
	 * Disable the SSP and disable interrupts
	 */
	outl( 0, SSPCR1 );

	/*
	 * Clock will be 14.7 MHz divided by 14.
	 */
	outl( 2, SSPCPSR );

	/*
	 * Configure EGPIO7 as an output and clear it.  This selects
	 * serial flash as the device on the SSP output instead of
	 * the I2S codec and is valid for EDB9301, EDB9302, EDB9307, EDB9312,
	 * and EDB9315.
	 */
	outl( inl(GPIO_PADDR) | 0x80, GPIO_PADDR );
	outl( inl(GPIO_PADR) & ~0x80, GPIO_PADR );

    /*
     * Disable SFRM1 to I2S codec by setting EGPIO8 (port B, bit 0).
     * The EDB9307 and EDB9315 boards need this.
     */
#if defined(CONFIG_ARCH_EDB9307) || defined(CONFIG_ARCH_EDB9315)
    uiRegTemp = inl(GPIO_PBDDR) | 0x01;
    outl( uiRegTemp, GPIO_PBDDR );

    uiRegTemp = inl(GPIO_PBDR) | 0x01;
    outl( uiRegTemp, GPIO_PBDR );
	
	uiRegTemp = inl(GPIO_PBDR);
#endif

    /*
     * Disable SFRM1 to I2S codec I2S by setting EGPIO6 (port A, bit 6).
     * The EDB9301 and EDB9302 boards needs this.
     */
#if defined(CONFIG_ARCH_EDB9301) || defined(CONFIG_ARCH_EDB9302)
	uiRegTemp = inl(GPIO_PADDR);
	outl( uiRegTemp | 0x40, GPIO_PADDR );

	uiRegTemp = inl(GPIO_PADR);
	outl( uiRegTemp | 0x40, GPIO_PADR );

	uiRegTemp = inl(GPIO_PBDR);
#endif

	/*
	 * Motorola format, 8 bit.
	 */
	outl( ((6 << SSPCR0_SCR_SHIFT) | SSPCR0_SPO | SSPCR0_SPH |
	       SSPCR0_FRF_MOTOROLA | SSPCR0_DSS_8BIT),
	      SSPCR0 );

	/*
	 * Configure the device as master, reenable the device.
	 */
	outl( SSPC1_SSE, SSPCR1 );

	gSSPmode = SSP_MODE_FLASH;

	udelay(10);
}

/*
 *  CheckHandle
 *
 *  If Handle is valid, returns 0.  Otherwise it returns -1.
 */
static int CheckHandle(int Handle)
{
	int iRet;

	if ((Handle != KeyboardHandle) &&
	    (Handle != I2SHandle) &&
	    (Handle != FlashHandle))
	{
		DPRINTK("OOPS! Invalid SSP Handle!\n");
		return(-1);
	}

	/*
	 * Get the SSP driver instance number from the handle.
	 */
	iRet = (((int)Handle & SSP_DEVICE_MASK) >> SSP_DEVICE_SHIFT);

	return iRet;
}

/*
 * ReadIntoBuffer
 *
 * Drains the SSP rx fifo into a buffer here.  If we overflow this buffer
 * then something's wrong.
 */
static int ReadIntoBuffer(void)
{
	unsigned int count, index, saved_count, uiRegTemp;
	
	count = 0;
	index = 0;


	if( gSSPmode != SSP_MODE_PS2 )
	{
		return 0;
	}
	
	/*
	 * This spinlock will prevent I2S from grabbing the SSP to do a
	 * write while we are using the SSP for PS2.
	 *
	 * There is a slight chance that we are in the beginning phase
	 * of doing an I2S write but the mode flag hadn't yet switched
	 * to I2S.  If that happens we will end up waiting on I2S to
	 * finish a write.  Not great.
	 */
	spin_lock(&ssp_spinlock);

	while( inl(SSPSR) & SSPSR_RNE)
	{
		/*
		 * Read in the value from the SPI controller into
		 * the partial key buffer.
		 */
		uiKeyBuffer[count] = inl(SSPDR);
		if (((uiKeyBuffer[count] & 0x3fc) != 0x3e0) &&
			((uiKeyBuffer[count] & 0x3fc) != 0x3c0))
		{
			/*
			 * Set GPIO pins 12 and 14, this will bring the clock line low
			 * which signals to the keyboard to buffer keystrokes.
			 * Note that EGPIO 14 is the clock line and EGPIO 12 is data line.
			 */
			uiRegTemp = inl(GPIO_PBDR);
			outl( 0x50 | uiRegTemp, GPIO_PBDR );

			outl( 0, SSPCR1 );
			outl( (SSPC1_MS | SSPC1_RIE | SSPC1_SSE), SSPCR1 );

			/*
			 * Clear EGPIO pins 12 and 14, this will enable the SPI keyboard.
			 */
			uiRegTemp = inl(GPIO_PBDR);
			outl( uiRegTemp & ~0x50, GPIO_PBDR );

			count++;
			break;
		}
		count++;
	}

	saved_count = count;
	index = 0;
	while (count)
	{
		//
		// No callback, dump data.
		//
		if (gKeyCallback)
		{
			gKeyCallback(uiKeyBuffer[index++]);
		}
		count--;
	}

	spin_unlock(&ssp_spinlock);

	return saved_count;
}

/*
 * SSP_Write_I2SCodec
 *
 */
static int SSP_Write_I2SCodec
(
	int Handle,
	unsigned int RegAddr,
	unsigned int RegValue
)
{
	SSPmodes_t saved_mode;

	DPRINTK("SSP_Write_I2SCodec\n");

	spin_lock(&ssp_spinlock);

	/*
	 * Save the SSP mode.  Switch to I2S mode if we're not
	 * already in I2S mode.
	 */
	saved_mode = gSSPmode;
	SetSSPtoI2S();

	/*
	 * Let TX fifo clear out.  Poll the Transmit Fifo Empty bit.
	 */
	while( !( inl(SSPSR) & SSPSR_TFE ) );
	
	/*
	 * Write the data out to the tx fifo.
	 */
	outl( 0x20, SSPDR ); /* chip address for CS4228 */
	outl( (RegAddr & 0xff), SSPDR );
	outl( (RegValue & 0xff), SSPDR );

	/*
	 * Let TX fifo clear out.  Poll the Transmit Fifo Empty bit.
	 */
	while( !( inl(SSPSR) & SSPSR_TFE ) );

	/*
	 * Delay to let stuff make it out of the SR before doing
	 * anthing else to the SSP.  It takes 6.8 uSec to do a
	 * I2S codec register write.
	 */
	udelay(10);

	/*
	 * If we were in PS2 mode, switch back to PS2 mode.
	 * If we weren't in PS2 mode, that means we didn't compile in
	 * the PS2 keyboard support, so no need to switch to PS2 mode.
	 */
	if( saved_mode == SSP_MODE_PS2 )
	{
		SetSSPtoPS2();
	}

	spin_unlock(&ssp_spinlock);

	/*
	 * Return success.
	 */
	return 0;
}