pxa_camera-hzh.c

基于intel xscale下的linux系统camera驱动程序

	if (parity_check) {
		value |= CI_CICR0_PAR_EN;
	}
	else {
		value &= ~CI_CICR0_PAR_EN;
	}
	CICR0 = value;   
	return; 
}
//嵌串
void ci_configure_es(int parity_check)
{
	// the operationi is same as Embedded-Parallel
	ci_configure_ep(parity_check);
}
//设置mclk频率和mclk及pclk是否由CPU产生(ciclk=104M,mclk=24M由CPU产生,pclk由sensor产生)
void ci_set_clock(unsigned int clk_regs_base, int pclk_enable, int mclk_enable, unsigned int mclk_khz)
{
	unsigned int ciclk = 0,  value, div, cccr_l;

	// determine the LCLK frequency programmed into the CCCR.
	cccr_l = (CCCR & 0x0000001F);

        if (cccr_l < 8) // L = [2 - 7]
                ciclk = (13 * cccr_l) * 100;
        else if (cccr_l < 17) // L = [8 - 16]
               ciclk = ((13 * cccr_l) * 100) >> 1;
        else if (cccr_l < 32) // L = [17 - 31]
               ciclk = ((13 * cccr_l) * 100) >> 2;

        // want a divisor that gives us a clock rate as close to, but not more than the given mclk.
        div = (ciclk / (2 * mclk_khz));
	div = div - 1;

	// write cicr4
	value = CICR4;
	value &= ~(CI_CICR4_PCLK_EN | CI_CICR4_MCLK_EN | CI_CICR4_DIV_SMASK<<CI_CICR4_DIV_SHIFT);
	value |= (pclk_enable) ? CI_CICR4_PCLK_EN : 0;
	value |= (mclk_enable) ? CI_CICR4_MCLK_EN : 0;
	value |= div << CI_CICR4_DIV_SHIFT;
	CICR4 = value;   
	return; 
}
//设置采样有效边缘和同步信号有效极性
void ci_set_polarity(int pclk_sample_falling, int hsync_active_low, int vsync_active_low)
{
	unsigned int value;
	
	// write cicr4
	value = CICR4;
	value &= ~(CI_CICR4_PCP | CI_CICR4_HSP | CI_CICR4_VSP);
	value |= (pclk_sample_falling)? CI_CICR4_PCP : 0;
	value |= (hsync_active_low) ? CI_CICR4_HSP : 0;
	value |= (vsync_active_low) ? CI_CICR4_VSP : 0;
	CICR4 = value;   
	return; 
}
//设置超时参数和FIFO启动DMA的阀值和使能/禁止FIFO1,FIFO2(FIFO现已可自动使能)
void ci_set_fifo(unsigned int timeout, CI_FIFO_THRESHOLD threshold, int fifo1_enable,
               int fifo2_enable)
{
	unsigned int value;

	// write citor
	CITOR = timeout; 
	
	// write cifr: always enable fifo 0! also reset input fifo 
	value = CIFR;
	value &= ~(CI_CIFR_FEN0 | CI_CIFR_FEN1 | CI_CIFR_FEN2 | CI_CIFR_RESETF | 
	CI_CIFR_THL_0_SMASK<<CI_CIFR_THL_0_SHIFT);
	value |= (unsigned int)threshold << CI_CIFR_THL_0_SHIFT;
	value |= (fifo1_enable) ? CI_CIFR_FEN1 : 0;
	value |= (fifo2_enable) ? CI_CIFR_FEN2 : 0;
	value |= CI_CIFR_RESETF | CI_CIFR_FEN0;
	CIFR = value;
	return; 
}

void ci_reset_fifo(void)
{
	unsigned int value;
	value = CIFR;
	value |= CI_CIFR_RESETF;
	CIFR = value;
}
//设置中断掩码
void ci_set_int_mask(unsigned int mask)
{
	unsigned int value;

	// write mask in cicr0  
	value = CICR0;
	value &= ~CI_CICR0_INTERRUPT_MASK;
	value |= (mask & CI_CICR0_INTERRUPT_MASK);
	CICR0 = value;   
	return; 
}
//获取中断掩码
unsigned int ci_get_int_mask(void)
{
	unsigned int value;

	// write mask in cicr0  
	value = CICR0;
	return (value & CI_CICR0_INTERRUPT_MASK);
}
//清除中断
void ci_clear_int_status(unsigned int status)
{
	// write 1 to clear
	CISR = status;
}
//读中断状态
unsigned int ci_get_int_status(void)
{
	int value;

	value = CISR;

	return  value;
}
//写和读camera控制寄存器
void ci_set_reg_value(unsigned int reg_offset, unsigned int value)
{
	CI_REG((u32)(ci_regs_base) + reg_offset) = value;
}

int ci_get_reg_value(unsigned int reg_offset)
{
	int value;

	value = CI_REG((u32)(ci_regs_base) + reg_offset);
	return value;
}

//-------------------------------------------------------------------------------------------------------
//  Control APIs
//-------------------------------------------------------------------------------------------------------
int ci_init(void)
{
	int cken_val;
	(unsigned long*)ci_regs_base = (unsigned long*)ioremap(CI_REGS_PHYS, CI_REG_SIZE);
	if(!ci_regs_base) {
		printk ("ci regs base apply failed \n");
		return -1;
	}

	// clear all CI registers
	CICR0 = 0x3FF;   // disable all interrupts
	CICR1 = 0;
	CICR2 = 0;
	CICR3 = 0;
	CICR4 = 0;
	CISR  = ~0;
	CIFR  = 0;
	CITOR = 0;
	
	// enable CI clock
	cken_val = CKEN;
	cken_val |= CKEN24_CAMERA;
	CKEN = cken_val;
	return 0;
}

void ci_deinit()
{
	// disable CI clock
	CKEN &= ~CKEN24_CAMERA;
}

void ci_enable(int dma_en)
{
	unsigned int value;

	// write mask in cicr0  
	value = CICR0;
	value |= CI_CICR0_ENB;
	if (dma_en) {
		value |= CI_CICR0_DMA_EN;
	}
	CICR0 = value;   
	return; 
}
//关闭camera,有快速和等待当前祯采样完毕两种模式
int ci_disable(int quick)
{
	volatile unsigned int value, mask;
	int retry;

	// write control bit in cicr0   
	value = CICR0;
	if (quick) {
		value &= ~CI_CICR0_ENB;
		mask = CI_CISR_CQD;
	}
	else {
		value |= CI_CICR0_DIS;
		mask = CI_CISR_CDD;
	}
	CICR0 = value;   
	
	// wait shutdown complete
	retry = 50;
	while ( retry-- > 0 ) {
		value = CISR;
		if ( value & mask ) {
			CISR = mask;
			return 0;
		}
		mdelay(10);
	}

	return -1; 
}

void ci_slave_capture_enable()
{
	unsigned int value;

	// write mask in cicr0  
	value = CICR0;
	value |= CI_CICR0_SL_CAP_EN;
	CICR0 = value;   
	return; 
}

void ci_slave_capture_disable()
{
	unsigned int value;
	
	// write mask in cicr0  
	value = CICR0;
	value &= ~CI_CICR0_SL_CAP_EN;
	CICR0 = value;   
	return; 
}
//DMA中断处理程序,只在Y通道结束才做具体操作
void pxa_ci_dma_irq_y(int channel, void *data, struct pt_regs *regs)
{
	int dcsr;
	static int dma_repeated=0;
	camera_context_t  *cam_ctx = g_camera_context;

	dcsr = DCSR(channel);
	DCSR(channel) = dcsr & ~DCSR_STOPIRQEN;

	if (still_image_mode == 1) {
		if (task_waiting == 1) {
			wake_up_interruptible (&camera_wait_q);
			task_waiting = 0;
		}
		else {
			still_image_rdy = 1;
		}
	} 	//当尾块索引(读取数据时修改)与头块索引(DMA结束时修改)只差1时,在尾块前一块重复DMA以防止覆盖数据
	else 	if (dma_repeated == 0 
		&& (cam_ctx->block_tail == ((cam_ctx->block_header + 2) % cam_ctx->block_number)))  {
		dma_repeated = 1;
		pxa_dma_repeat(cam_ctx);
		cam_ctx->block_header = (cam_ctx->block_header + 1) % cam_ctx->block_number;
	}	//如前面有重复一块DMA操作,在条件满足时(数据已被读出,尾块已变)恢复DMA循环操作
	else if (dma_repeated == 1 && 
			(cam_ctx->block_tail != ((cam_ctx->block_header + 1) % cam_ctx->block_number))
			&& (cam_ctx->block_tail != ((cam_ctx->block_header + 2) % cam_ctx->block_number)))  {
			pxa_dma_continue(cam_ctx);
			dma_repeated = 0;
	}
	else if (dma_repeated == 0) {
		cam_ctx->block_header = (cam_ctx->block_header + 1) % cam_ctx->block_number;
	}

	if (task_waiting == 1 && !(cam_ctx->block_header == cam_ctx->block_tail)) {
			wake_up_interruptible (&camera_wait_q);
		task_waiting = 0;
	}
	return;
}

void pxa_ci_dma_irq_cb(int channel, void *data, struct pt_regs *regs)
{
	return;
}

void pxa_ci_dma_irq_cr(int channel, void *data, struct pt_regs *regs)
{
	return;
}
                                                                                                                     
inline static void pxa_ci_dma_stop(camera_context_t  *cam_ctx)
{
        int ch0, ch1, ch2;
        
        ch0 = cam_ctx->dma_channels[0];
        ch1 = cam_ctx->dma_channels[1];
        ch2 = cam_ctx->dma_channels[2];
        DCSR(ch0) &= ~DCSR_RUN;
        DCSR(ch1) &= ~DCSR_RUN;
        DCSR(ch2) &= ~DCSR_RUN;
}
                                                                                                                             
//填充DMA目的地址并启动DMA操作
void pxa_dma_start(camera_context_t  *cam_ctx)
{
        unsigned char cnt_blk;
        pxa_dma_desc   *cnt_desc;

	cam_ctx->block_header = (cam_ctx->block_header + 1) % cam_ctx->block_number;
        cnt_blk = (unsigned char)cam_ctx->block_header;
	
        cnt_desc = (pxa_dma_desc *)cam_ctx->fifo0_descriptors_physical + cnt_blk * cam_ctx->fifo0_num_descriptors;

        DDADR(cam_ctx->dma_channels[0]) = (int) cnt_desc;
        DCSR(cam_ctx->dma_channels[0]) |= DCSR_RUN;

        if (cam_ctx->fifo1_num_descriptors) {
                cnt_desc = (pxa_dma_desc *)cam_ctx->fifo1_descriptors_physical + cnt_blk * cam_ctx->fifo1_num_descriptors; 
                DDADR(cam_ctx->dma_channels[1]) = (int) cnt_desc;
                DCSR(cam_ctx->dma_channels[1]) |= DCSR_RUN;
        }

        if (cam_ctx->fifo2_num_descriptors) {
                cnt_desc = (pxa_dma_desc *)cam_ctx->fifo2_descriptors_physical + cnt_blk * cam_ctx->fifo2_num_descriptors; 
                DDADR(cam_ctx->dma_channels[2]) = (int) cnt_desc;
                DCSR(cam_ctx->dma_channels[2]) |= DCSR_RUN;
        }
	
	return;
}


irqreturn_t pxa_camera_irq(int irq, void *dev_id, struct pt_regs *regs)	
{
        int cisr;
        static int dma_started=0;

	disable_irq(IRQ_CAMERA);
        cisr = CISR;
        if (cisr & CI_CISR_SOF) {
		if (dma_started == 0) {
			dma_started = 1;
		}
                CISR |= CI_CISR_SOF;
        }
        if (cisr & CI_CISR_EOF) {
                CISR |= CI_CISR_EOF;
        }

	enable_irq(IRQ_CAMERA);
	return IRQ_HANDLED;	
}

void pxa_dma_repeat(camera_context_t  *cam_ctx)
{
	pxa_dma_desc *cnt_head, *cnt_tail; 
	int cnt_block;

	cnt_block = (cam_ctx->block_header + 1) % cam_ctx->block_number;
// FIFO0
	(pxa_dma_desc *)cnt_head = (pxa_dma_desc *)cam_ctx->fifo0_descriptors_virtual + cnt_block * cam_ctx->fifo0_num_descriptors;
	cnt_tail = cnt_head + cam_ctx->fifo0_num_descriptors - 1;
	cnt_tail->ddadr = cnt_head->ddadr - sizeof(pxa_dma_desc);
// FIFO1
	if (cam_ctx->fifo1_transfer_size) {
		cnt_head = (pxa_dma_desc *)cam_ctx->fifo1_descriptors_virtual + cnt_block * cam_ctx->fifo1_num_descriptors;
		cnt_tail = cnt_head + cam_ctx->fifo1_num_descriptors - 1;
		cnt_tail->ddadr = cnt_head->ddadr - sizeof(pxa_dma_desc);
	}
// FIFO2
	if (cam_ctx->fifo2_transfer_size) {
		cnt_head = (pxa_dma_desc *)cam_ctx->fifo2_descriptors_virtual + cnt_block * cam_ctx->fifo2_num_descriptors;
		cnt_tail = cnt_head + cam_ctx->fifo2_num_descriptors - 1;
		cnt_tail->ddadr = cnt_head->ddadr - sizeof(pxa_dma_desc);
	}
	return;
}

void pxa_dma_continue(camera_context_t *cam_ctx)
{
	pxa_dma_desc *cnt_head, *cnt_tail; 
	pxa_dma_desc *next_head;
	int cnt_block, next_block;
	
	cnt_block = cam_ctx->block_header;
	next_block = (cnt_block + 1) % cam_ctx->block_number;
// FIFO0	
	cnt_head = (pxa_dma_desc *)cam_ctx->fifo0_descriptors_virtual + cnt_block * cam_ctx->fifo0_num_descriptors;
	cnt_tail = cnt_head + cam_ctx->fifo0_num_descriptors - 1;
	next_head = (pxa_dma_desc *)cam_ctx->fifo0_descriptors_virtual + next_block * cam_ctx->fifo0_num_descriptors;
	cnt_tail->ddadr = next_head->ddadr - sizeof(pxa_dma_desc);
// FIFO1
	if (cam_ctx->fifo1_transfer_size) {
		cnt_head = (pxa_dma_desc *)cam_ctx->fifo1_descriptors_virtual + cnt_block * cam_ctx->fifo1_num_descriptors;
		cnt_tail = cnt_head + cam_ctx->fifo1_num_descriptors - 1;
		next_head = (pxa_dma_desc *)cam_ctx->fifo1_descriptors_virtual + next_block * cam_ctx->fifo1_num_descriptors;
		cnt_tail->ddadr = next_head->ddadr - sizeof(pxa_dma_desc);
	}
// FIFO2
	if (cam_ctx->fifo2_transfer_size) {
		cnt_head = (pxa_dma_desc *)cam_ctx->fifo2_descriptors_virtual + cnt_block * cam_ctx->fifo2_num_descriptors;
		cnt_tail = cnt_head + cam_ctx->fifo2_num_descriptors - 1;
		next_head = (pxa_dma_desc *)cam_ctx->fifo2_descriptors_virtual + next_block * cam_ctx->fifo2_num_descriptors;
		cnt_tail->ddadr = next_head->ddadr - sizeof(pxa_dma_desc);
	}
	return;
}

module_init(pxa_camera_init);
module_exit(pxa_camera_exit);

MODULE_DESCRIPTION("Bulverde Camera Interface driver");
MODULE_LICENSE("GPL");