xref: /openbmc/linux/drivers/staging/sm750fb/ddk750_sii164.c (revision 72eb8304)

// SPDX-License-Identifier: GPL-2.0
#define USE_DVICHIP
#ifdef USE_DVICHIP

#include "ddk750_sii164.h"
#include "ddk750_hwi2c.h"

/* I2C Address of each SII164 chip */
#define SII164_I2C_ADDRESS                  0x70

/* Define this definition to use hardware i2c. */
#define USE_HW_I2C

#ifdef USE_HW_I2C
    #define i2cWriteReg sm750_hw_i2c_write_reg
    #define i2cReadReg  sm750_hw_i2c_read_reg
#else
    #define i2cWriteReg sm750_sw_i2c_write_reg
    #define i2cReadReg  sm750_sw_i2c_read_reg
#endif

/* SII164 Vendor and Device ID */
#define SII164_VENDOR_ID                    0x0001
#define SII164_DEVICE_ID                    0x0006

#ifdef SII164_FULL_FUNCTIONS
/* Name of the DVI Controller chip */
static char *gDviCtrlChipName = "Silicon Image SiI 164";
#endif

/*
 *  sii164_get_vendor_id
 *      This function gets the vendor ID of the DVI controller chip.
 *
 *  Output:
 *      Vendor ID
 */
unsigned short sii164_get_vendor_id(void)
{
	unsigned short vendorID;

	vendorID = ((unsigned short)i2cReadReg(SII164_I2C_ADDRESS,
					       SII164_VENDOR_ID_HIGH) << 8) |
		   (unsigned short)i2cReadReg(SII164_I2C_ADDRESS,
					      SII164_VENDOR_ID_LOW);

	return vendorID;
}

/*
 *  sii164GetDeviceID
 *      This function gets the device ID of the DVI controller chip.
 *
 *  Output:
 *      Device ID
 */
unsigned short sii164GetDeviceID(void)
{
	unsigned short deviceID;

	deviceID = ((unsigned short)i2cReadReg(SII164_I2C_ADDRESS,
					       SII164_DEVICE_ID_HIGH) << 8) |
		   (unsigned short)i2cReadReg(SII164_I2C_ADDRESS,
					      SII164_DEVICE_ID_LOW);

	return deviceID;
}

/*
 *  DVI.C will handle all SiI164 chip stuffs and try its best to make code
 *  minimal and useful
 */

/*
 *  sii164_init_chip
 *      This function initialize and detect the DVI controller chip.
 *
 *  Input:
 *      edge_select           - Edge Select:
 *                               0 = Input data is falling edge latched (falling
 *                                   edge latched first in dual edge mode)
 *                               1 = Input data is rising edge latched (rising
 *                                   edge latched first in dual edge mode)
 *      bus_select            - Input Bus Select:
 *                               0 = Input data bus is 12-bits wide
 *                               1 = Input data bus is 24-bits wide
 *      dual_edge_clk_select  - Dual Edge Clock Select
 *                               0 = Input data is single edge latched
 *                               1 = Input data is dual edge latched
 *      hsync_enable          - Horizontal Sync Enable:
 *                               0 = HSYNC input is transmitted as fixed LOW
 *                               1 = HSYNC input is transmitted as is
 *      vsync_enable          - Vertical Sync Enable:
 *                               0 = VSYNC input is transmitted as fixed LOW
 *                               1 = VSYNC input is transmitted as is
 *      deskew_enable         - De-skewing Enable:
 *                               0 = De-skew disabled
 *                               1 = De-skew enabled
 *      deskew_setting        - De-skewing Setting (increment of 260psec)
 *                               0 = 1 step --> minimum setup / maximum hold
 *                               1 = 2 step
 *                               2 = 3 step
 *                               3 = 4 step
 *                               4 = 5 step
 *                               5 = 6 step
 *                               6 = 7 step
 *                               7 = 8 step --> maximum setup / minimum hold
 *      continuous_sync_enable- SYNC Continuous:
 *                               0 = Disable
 *                               1 = Enable
 *      pll_filter_enable     - PLL Filter Enable
 *                               0 = Disable PLL Filter
 *                               1 = Enable PLL Filter
 *      pll_filter_value      - PLL Filter characteristics:
 *                               0~7 (recommended value is 4)
 *
 *  Output:
 *      0   - Success
 *     -1   - Fail.
 */
long sii164_init_chip(unsigned char edge_select,
		      unsigned char bus_select,
		      unsigned char dual_edge_clk_select,
		      unsigned char hsync_enable,
		      unsigned char vsync_enable,
		      unsigned char deskew_enable,
		      unsigned char deskew_setting,
		      unsigned char continuous_sync_enable,
		      unsigned char pll_filter_enable,
		      unsigned char pll_filter_value)
{
	unsigned char config;

	/* Initialize the i2c bus */
#ifdef USE_HW_I2C
	/* Use fast mode. */
	sm750_hw_i2c_init(1);
#else
	sm750_sw_i2c_init(DEFAULT_I2C_SCL, DEFAULT_I2C_SDA);
#endif

	/* Check if SII164 Chip exists */
	if ((sii164_get_vendor_id() == SII164_VENDOR_ID) &&
	    (sii164GetDeviceID() == SII164_DEVICE_ID)) {
		/*
		 *  Initialize SII164 controller chip.
		 */

		/* Select the edge */
		if (edge_select == 0)
			config = SII164_CONFIGURATION_LATCH_FALLING;
		else
			config = SII164_CONFIGURATION_LATCH_RISING;

		/* Select bus wide */
		if (bus_select == 0)
			config |= SII164_CONFIGURATION_BUS_12BITS;
		else
			config |= SII164_CONFIGURATION_BUS_24BITS;

		/* Select Dual/Single Edge Clock */
		if (dual_edge_clk_select == 0)
			config |= SII164_CONFIGURATION_CLOCK_SINGLE;
		else
			config |= SII164_CONFIGURATION_CLOCK_DUAL;

		/* Select HSync Enable */
		if (hsync_enable == 0)
			config |= SII164_CONFIGURATION_HSYNC_FORCE_LOW;
		else
			config |= SII164_CONFIGURATION_HSYNC_AS_IS;

		/* Select VSync Enable */
		if (vsync_enable == 0)
			config |= SII164_CONFIGURATION_VSYNC_FORCE_LOW;
		else
			config |= SII164_CONFIGURATION_VSYNC_AS_IS;

		i2cWriteReg(SII164_I2C_ADDRESS, SII164_CONFIGURATION, config);

		/*
		 * De-skew enabled with default 111b value.
		 * This fixes some artifacts problem in some mode on board 2.2.
		 * Somehow this fix does not affect board 2.1.
		 */
		if (deskew_enable == 0)
			config = SII164_DESKEW_DISABLE;
		else
			config = SII164_DESKEW_ENABLE;

		switch (deskew_setting) {
		case 0:
			config |= SII164_DESKEW_1_STEP;
			break;
		case 1:
			config |= SII164_DESKEW_2_STEP;
			break;
		case 2:
			config |= SII164_DESKEW_3_STEP;
			break;
		case 3:
			config |= SII164_DESKEW_4_STEP;
			break;
		case 4:
			config |= SII164_DESKEW_5_STEP;
			break;
		case 5:
			config |= SII164_DESKEW_6_STEP;
			break;
		case 6:
			config |= SII164_DESKEW_7_STEP;
			break;
		case 7:
			config |= SII164_DESKEW_8_STEP;
			break;
		}
		i2cWriteReg(SII164_I2C_ADDRESS, SII164_DESKEW, config);

		/* Enable/Disable Continuous Sync. */
		if (continuous_sync_enable == 0)
			config = SII164_PLL_FILTER_SYNC_CONTINUOUS_DISABLE;
		else
			config = SII164_PLL_FILTER_SYNC_CONTINUOUS_ENABLE;

		/* Enable/Disable PLL Filter */
		if (pll_filter_enable == 0)
			config |= SII164_PLL_FILTER_DISABLE;
		else
			config |= SII164_PLL_FILTER_ENABLE;

		/* Set the PLL Filter value */
		config |= ((pll_filter_value & 0x07) << 1);

		i2cWriteReg(SII164_I2C_ADDRESS, SII164_PLL, config);

		/* Recover from Power Down and enable output. */
		config = i2cReadReg(SII164_I2C_ADDRESS, SII164_CONFIGURATION);
		config |= SII164_CONFIGURATION_POWER_NORMAL;
		i2cWriteReg(SII164_I2C_ADDRESS, SII164_CONFIGURATION, config);

		return 0;
	}

	/* Return -1 if initialization fails. */
	return -1;
}

/* below sii164 function is not necessary */

#ifdef SII164_FULL_FUNCTIONS

/*
 *  sii164ResetChip
 *      This function resets the DVI Controller Chip.
 */
void sii164ResetChip(void)
{
	/* Power down */
	sii164SetPower(0);
	sii164SetPower(1);
}

/*
 * sii164GetChipString
 *      This function returns a char string name of the current DVI Controller
 *      chip.
 *
 *      It's convenient for application need to display the chip name.
 */
char *sii164GetChipString(void)
{
	return gDviCtrlChipName;
}

/*
 *  sii164SetPower
 *      This function sets the power configuration of the DVI Controller Chip.
 *
 *  Input:
 *      powerUp - Flag to set the power down or up
 */
void sii164SetPower(unsigned char powerUp)
{
	unsigned char config;

	config = i2cReadReg(SII164_I2C_ADDRESS, SII164_CONFIGURATION);
	if (powerUp == 1) {
		/* Power up the chip */
		config &= ~SII164_CONFIGURATION_POWER_MASK;
		config |= SII164_CONFIGURATION_POWER_NORMAL;
		i2cWriteReg(SII164_I2C_ADDRESS, SII164_CONFIGURATION, config);
	} else {
		/* Power down the chip */
		config &= ~SII164_CONFIGURATION_POWER_MASK;
		config |= SII164_CONFIGURATION_POWER_DOWN;
		i2cWriteReg(SII164_I2C_ADDRESS, SII164_CONFIGURATION, config);
	}
}

/*
 *  sii164SelectHotPlugDetectionMode
 *      This function selects the mode of the hot plug detection.
 */
static
void sii164SelectHotPlugDetectionMode(enum sii164_hot_plug_mode hotPlugMode)
{
	unsigned char detectReg;

	detectReg = i2cReadReg(SII164_I2C_ADDRESS, SII164_DETECT) &
		    ~SII164_DETECT_MONITOR_SENSE_OUTPUT_FLAG;
	switch (hotPlugMode) {
	case SII164_HOTPLUG_DISABLE:
		detectReg |= SII164_DETECT_MONITOR_SENSE_OUTPUT_HIGH;
		break;
	case SII164_HOTPLUG_USE_MDI:
		detectReg &= ~SII164_DETECT_INTERRUPT_MASK;
		detectReg |= SII164_DETECT_INTERRUPT_BY_HTPLG_PIN;
		detectReg |= SII164_DETECT_MONITOR_SENSE_OUTPUT_MDI;
		break;
	case SII164_HOTPLUG_USE_RSEN:
		detectReg |= SII164_DETECT_MONITOR_SENSE_OUTPUT_RSEN;
		break;
	case SII164_HOTPLUG_USE_HTPLG:
		detectReg |= SII164_DETECT_MONITOR_SENSE_OUTPUT_HTPLG;
		break;
	}

	i2cWriteReg(SII164_I2C_ADDRESS, SII164_DETECT, detectReg);
}

/*
 *  sii164EnableHotPlugDetection
 *      This function enables the Hot Plug detection.
 *
 *  enableHotPlug   - Enable (=1) / disable (=0) Hot Plug detection
 */
void sii164EnableHotPlugDetection(unsigned char enableHotPlug)
{
	unsigned char detectReg;

	detectReg = i2cReadReg(SII164_I2C_ADDRESS, SII164_DETECT);

	/* Depending on each DVI controller, need to enable the hot plug based
	 * on each individual chip design.
	 */
	if (enableHotPlug != 0)
		sii164SelectHotPlugDetectionMode(SII164_HOTPLUG_USE_MDI);
	else
		sii164SelectHotPlugDetectionMode(SII164_HOTPLUG_DISABLE);
}

/*
 *  sii164IsConnected
 *      Check if the DVI Monitor is connected.
 *
 *  Output:
 *      0   - Not Connected
 *      1   - Connected
 */
unsigned char sii164IsConnected(void)
{
	unsigned char hotPlugValue;

	hotPlugValue = i2cReadReg(SII164_I2C_ADDRESS, SII164_DETECT) &
		       SII164_DETECT_HOT_PLUG_STATUS_MASK;
	if (hotPlugValue == SII164_DETECT_HOT_PLUG_STATUS_ON)
		return 1;
	else
		return 0;
}

/*
 *  sii164CheckInterrupt
 *      Checks if interrupt has occurred.
 *
 *  Output:
 *      0   - No interrupt
 *      1   - Interrupt occurs
 */
unsigned char sii164CheckInterrupt(void)
{
	unsigned char detectReg;

	detectReg = i2cReadReg(SII164_I2C_ADDRESS, SII164_DETECT) &
		    SII164_DETECT_MONITOR_STATE_MASK;
	if (detectReg == SII164_DETECT_MONITOR_STATE_CHANGE)
		return 1;
	else
		return 0;
}

/*
 *  sii164ClearInterrupt
 *      Clear the hot plug interrupt.
 */
void sii164ClearInterrupt(void)
{
	unsigned char detectReg;

	/* Clear the MDI interrupt */
	detectReg = i2cReadReg(SII164_I2C_ADDRESS, SII164_DETECT);
	i2cWriteReg(SII164_I2C_ADDRESS, SII164_DETECT,
		    detectReg | SII164_DETECT_MONITOR_STATE_CLEAR);
}

#endif

#endif