lcdspi.c

Samsung LCD驱动（SPI接口）

#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/ctype.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/delay.h>

#include <asm/system.h>
#include <asm/hardware.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/uaccess.h>

#include "regs-pxa.h"
//#include "lcdspi.h"

#define DEBUG
#ifdef DEBUG
	#define DEBUG_LCDSPI		1
#else
	#define DEBUG_LCDSPI		0
#endif

#define Samsung_22

#define KERN_LEVEL		KERN_INFO	/* refer to kernel.h*/
#if DEBUG_LCDSPI
	#define DPRINTK(fmt, args...)	printk(KERN_LEVEL "<%s:%d> %s : " fmt "\n", __FILE__, __LINE__ , __FUNCTION__, ## args)
#else
	#define DPRINTK(fmt, args...)
#endif

#define SHOW_FUNCTION_ENTRY	DPRINTK("Begin >>>\n")
#define SHOW_FUNCTION_EXIT	DPRINTK("      <<< End\n")


#if defined(CONFIG_LCD_LG)
	#define DEVICE_ID	(0x1C | 1)
//#elif defined(CONFIG_LCD_TRULY)
#else
	#define DEVICE_ID	(0x10)
#endif

#define RS_INDEX_REGISTER	0
#define RS_CONTROL_REGISTER	1

#define RW_WRITE		0
#define RW_READ			1

#define START_BYTE(rs, rw)	((DEVICE_ID<<2) | (rs<<1) | rw)

#define HW_START_FRAME		(GPCR2 |= GPIO_bit(83)); udelay(2)	//GPIO_bit(83)== 0x00080000
#define HW_STOP_FRAME		(GPSR2 |= GPIO_bit(83)); udelay(2) //GPIO_bit(83)== 0x00080000
#define HW_SPI_TX_BUSY		((SSP3_SSSR) & 0x10)
#define HW_SPI_RX_BUSY		0
#define HW_SPI_FIFO_NOT_EMPTY	((SSP3_SSSR) & 0x08)


/**********************************************************************
* Function:         ssp3_init
* Description:      initialize SSP3
*
* Input:            none
* Output:           none
* Return:           0:success
* Others:           none
* Modify Date    Version    Author        Modification
* -----------------------------------------------
* 2004-5-31       V1.0      XZC           Create
**********************************************************************/
static int ssp3_init(void)
{
	SHOW_FUNCTION_ENTRY;

	/* Set GPIO */
	//SSP_TXD & SSP_SFRM & SSP_CLK are output
	GPDR2 |= (GPIO_bit(81) | GPIO_bit(83) | GPIO_bit(52));
	//SSP_RXD is input
	GPDR2 &= ~GPIO_bit(82);

	//SSP port is function 1
	GAFR2_U &= ~(GPIO_81_AF3 | GPIO_83_AF3 | GPIO_83_AF3);
	//2 INIT Option 1: SSPSFRM3 can be driven manually by GPIO or automatically by SSP
	GAFR2_U |= (GPIO_81_AF1_SSPTXD3 | GPIO_82_AF1_SSPRXD3);
	//GAFR2_U |= (GPIO_81_AF1_SSPTXD3 | GPIO_82_AF1_SSPRXD3 | GPIO_83_AF1_SSPSFRM3);
	GAFR1_U &= ~GPIO_52_AF3;
	GAFR1_U |= GPIO_52_AF2_SSPCLK3;

	GPSR2 |= GPIO_bit(83);

	//select on-chip clock
	SSP3_SSCR0 &= ~SPI_ECS;
	//2 INIT Option 2: SPI bit rate
	//SPI bit rate = SSPCLK/SCR+1
	//SSP3_SSCR0 |= SPI_SCR(2);
	SSP3_SSCR0 |= SPI_SCR(4095);
	//choose spi frame format
	SSP3_SSCR0 |= SPI_FRF(0);	//spi
	//2 INIT Option 3: SPI data width
	//select spi data width, 8
	SSP3_SSCR0 &= ~SPI_EDSS;
	SSP3_SSCR0 |= SPI_DSS(7);

	//2 INIT Option 4: SSPCLK idle mode and phase against SSPSFRM
	//SSP3_SSCR1 &= ~SPI_SPO;
	//SSP3_SSCR1 &= ~SPI_SPH;
	SSP3_SSCR1 |= SPI_SPO;
	SSP3_SSCR1 |= SPI_SPH;

	SSP3_SSCR1 &= ~SPI_MWDS;	//8-bit command word is transmitted,microwire protocol
	SSP3_SSCR1 |= SPI_TFT(2);	//transmit FIFO threshold
	SSP3_SSCR1 |= SPI_RFT(7);	//receive FIFO threshold

	//set loopback mode
	SSP3_SSCR1 &= ~SPI_LBM;

	//disable transmit/receive interupt
	SSP3_SSCR1 &= ~SPI_TIE;
	SSP3_SSCR1 &= ~SPI_RIE;

	//disable DMA
	//SSP3_SSCR1 &= ~SPI_RSRE;
	//SSP3_SSCR1 &= ~SPI_TSRE;

	//2 INIT Option 5: end of transfer data state, 0 = low, 1 = last value<bit 0>
	//SSP3_SSPSP &= ~SPI_ETDS;
	SSP3_SSPSP |= SPI_ETDS;

	//2 INIT Option 6: Invert Frame Signal
	SSP3_SSCR1 &= ~SPI_IFS;
	//SSP3_SSCR1 |= SPI_IFS;

	SHOW_FUNCTION_EXIT;

	return 0;
}

/**********************************************************************
* Function:         ssp3_enable
* Description:      enable SSP3
*
* Input:            none
* Output:           none
* Return:           0:success
* Others:           none
* Modify Date    Version    Author        Modification
* -----------------------------------------------
* 2004-08-05       V1.0      XZC           Create
* 2004-08-05       V1.1      XZC           Add call of ssp3_init
**********************************************************************/
void ssp3_enable(void)
{
	SHOW_FUNCTION_ENTRY;

	//if (0 == SSP3_SSCR0)
	if (!(SSP3_SSCR0 & SPI_SSE))
		ssp3_init();

	//enable SPI
	SSP3_SSCR0 |= SPI_SSE;

	//clock enable
	CKEN |= CKEN4_SSP3;

//	DPRINTK("SSP3_SSCR0 = 0x%x\n", SSP3_SSCR0);
//	DPRINTK("SSP3_SSCR1 = 0x%x\n", SSP3_SSCR1);

	SHOW_FUNCTION_EXIT;
}

/**********************************************************************
* Function:         ssp3_enable
* Description:      disable SSP3
*
* Input:            none
* Output:           none
* Return:           0:success
* Others:           none
* Modify Date    Version    Author        Modification
* -----------------------------------------------
* 2004-08-05       V1.0      XZC           Create
**********************************************************************/
void ssp3_disable(void)
{
	SHOW_FUNCTION_ENTRY;

	//disable SPI
	SSP3_SSCR0 &= ~SPI_SSE;

	//clock disable
	CKEN &= ~CKEN4_SSP3;

	SHOW_FUNCTION_EXIT;
}

/**********************************************************************
* Function:         spi_transaction
* Description:      implement SPI protocol for transaction
*
* Input:            p_data - pointer to source data
*                   count - count of source data
* Output:           none
* Return:           0:success
* Others:           none
* Modify Date    Version    Author        Modification
* -----------------------------------------------
* 2004-5-31       V1.0      XZC           Create
**********************************************************************/
static int spi_transaction(unsigned char *p_data, unsigned short count)
{
	unsigned short i;
	unsigned char temp;

	HW_START_FRAME;
	while (HW_SPI_TX_BUSY) { udelay(2); }
	for (i = 0; i < count; i++)
	{
		temp = p_data[i];
		SSP3_SSDR = temp;
		printk("%02x is transmitted, ", temp);
		udelay(2);
		while (HW_SPI_TX_BUSY) { udelay(2); }
		while (HW_SPI_RX_BUSY) { udelay(2); }
		temp = (unsigned char)SSP3_SSDR;
		printk("%02x is received\n", temp);
		udelay(2);
		if (i != 0)
		{
			p_data[i] = temp;
		}
		udelay(20);
	}
	while (HW_SPI_FIFO_NOT_EMPTY) // make sure getting latest data
	{
		temp = (unsigned char)SSP3_SSDR;
		printk("%02x is received in HW_SPI_FIFO_NOT_EMPTY\n", temp);
		for (i = 0; i < (count - 1); i++)
		{
			p_data[i] = p_data[i+1];
		}
		p_data[count-1] = temp;
		udelay(20);
	}
	HW_STOP_FRAME;
	udelay(20);
	return 0;
}


/**********************************************************************
* Function:         spi_select_register
* Description:      operation of selecting register
*
* Input:            index - index of target register
* Output:           none
* Return:           data in the register
* Others:           none
* Modify Date    Version    Author        Modification
* -----------------------------------------------
* 2004-5-31       V1.0      XZC           Create
**********************************************************************/
void spi_select_register(unsigned short index)
{
	unsigned char bytes[3]={0,0,0};

	bytes[0] = START_BYTE(RS_INDEX_REGISTER, RW_WRITE);	// = 0x74
	bytes[1] = (unsigned char)(index>>8);
	bytes[2] = (unsigned char)index;

	spi_transaction(bytes,3);
}

/**********************************************************************
* Function:         spi_read_register
* Description:      read data from LCD register
*
* Input:            index - index of target register
* Output:           none
* Return:           data in the register
* Others:           none
* Modify Date    Version    Author        Modification
* -----------------------------------------------
* 2004-5-31       V1.0      XZC           Create
**********************************************************************/
unsigned short spi_read_register(unsigned short index)
{
	unsigned short data = 0;
	unsigned char bytes[4] = {0,0,0,0};

	/* select register */
	spi_select_register(index);

	/* receive data */
	bytes[0] = START_BYTE(RS_CONTROL_REGISTER, RW_READ);	// = 0x77
	spi_transaction(bytes,4);

	data = (bytes[2]<<8) | bytes[3];
	return data;
}

/**********************************************************************
* Function:         spi_write_register
* Description:      write data to LCD register
*
* Input:            index - index of target register
*                   data - data to write into register
* Output:           none
* Return:           none
* Others:           none
* Modify Date    Version    Author        Modification
* -----------------------------------------------
* 2004-5-31       V1.0      XZC           Create
**********************************************************************/
void spi_write_register(unsigned short index, unsigned short data)
{
	unsigned char bytes[3] = {0,0,0};

	/* select register */
	spi_select_register(index);

	/* send data */
	bytes[0] = START_BYTE(RS_CONTROL_REGISTER, RW_WRITE);	// = 0x76
	bytes[1] = (unsigned char)(data>>8);
	bytes[2] = (unsigned char)data;
	spi_transaction(bytes,3);
}

/**********************************************************************
* Function:         spi_write_gram
* Description:      write data to LCD GRAM
*
* Input:            data - data to write into GRAM
* Output:           none
* Return:           none
* Others:           none
* Modify Date    Version    Author        Modification
* -----------------------------------------------
* 2004-5-31       V1.0      XZC           Create
**********************************************************************/