path: root/drivers/media/common/saa7146_hlp.c

#include <linux/kernel.h>
#include <media/saa7146_vv.h>

static void calculate_output_format_register(struct saa7146_dev* saa, u32 palette, u32* clip_format)
{
	/* clear out the necessary bits */
	*clip_format &= 0x0000ffff;
	/* set these bits new */
	*clip_format |=  (( ((palette&0xf00)>>8) << 30) | ((palette&0x00f) << 24) | (((palette&0x0f0)>>4) << 16));
}

static void calculate_hps_source_and_sync(struct saa7146_dev *dev, int source, int sync, u32* hps_ctrl)
{
	*hps_ctrl &= ~(MASK_30 | MASK_31 | MASK_28);
	*hps_ctrl |= (source << 30) | (sync << 28);
}

static void calculate_hxo_and_hyo(struct saa7146_vv *vv, u32* hps_h_scale, u32* hps_ctrl)
{
	int hyo = 0, hxo = 0;

	hyo = vv->standard->v_offset;
	hxo = vv->standard->h_offset;

	*hps_h_scale	&= ~(MASK_B0 | 0xf00);
	*hps_h_scale	|= (hxo <<  0);

	*hps_ctrl	&= ~(MASK_W0 | MASK_B2);
	*hps_ctrl	|= (hyo << 12);
}

/* helper functions for the calculation of the horizontal- and vertical
   scaling registers, clip-format-register etc ...
   these functions take pointers to the (most-likely read-out
   original-values) and manipulate them according to the requested
   changes.
*/

/* hps_coeff used for CXY and CXUV; scale 1/1 -> scale 1/64 */
static struct {
	u16 hps_coeff;
	u16 weight_sum;
} hps_h_coeff_tab [] = {
	{0x00,   2}, {0x02,   4}, {0x00,   4}, {0x06,   8}, {0x02,   8},
	{0x08,   8}, {0x00,   8}, {0x1E,  16}, {0x0E,   8}, {0x26,   8},
	{0x06,   8}, {0x42,   8}, {0x02,   8}, {0x80,   8}, {0x00,   8},
	{0xFE,  16}, {0xFE,   8}, {0x7E,   8}, {0x7E,   8}, {0x3E,   8},
	{0x3E,   8}, {0x1E,   8}, {0x1E,   8}, {0x0E,   8}, {0x0E,   8},
	{0x06,   8}, {0x06,   8}, {0x02,   8}, {0x02,   8}, {0x00,   8},
	{0x00,   8}, {0xFE,  16}, {0xFE,   8}, {0xFE,   8}, {0xFE,   8},
	{0xFE,   8}, {0xFE,   8}, {0xFE,   8}, {0xFE,   8}, {0xFE,   8},
	{0xFE,   8}, {0xFE,   8}, {0xFE,   8}, {0xFE,   8}, {0xFE,   8},
	{0xFE,   8}, {0xFE,   8}, {0xFE,   8}, {0xFE,   8}, {0x7E,   8},
	{0x7E,   8}, {0x3E,   8}, {0x3E,   8}, {0x1E,   8}, {0x1E,   8},
	{0x0E,   8}, {0x0E,   8}, {0x06,   8}, {0x06,   8}, {0x02,   8},
	{0x02,   8}, {0x00,   8}, {0x00,   8}, {0xFE,  16}
};

/* table of attenuation values for horizontal scaling */
static u8 h_attenuation[] = { 1, 2, 4, 8, 2, 4, 8, 16, 0};

/* calculate horizontal scale registers */
static int calculate_h_scale_registers(struct saa7146_dev *dev,
	int in_x, int out_x, int flip_lr,
	u32* hps_ctrl, u32* hps_v_gain, u32* hps_h_prescale, u32* hps_h_scale)
{
	/* horizontal prescaler */
	u32 dcgx = 0, xpsc = 0, xacm = 0, cxy = 0, cxuv = 0;
	/* horizontal scaler */
	u32 xim = 0, xp = 0, xsci =0;
	/* vertical scale & gain */
	u32 pfuv = 0;

	/* helper variables */
	u32 h_atten = 0, i = 0;

	if ( 0 == out_x ) {
		return -EINVAL;
	}

	/* mask out vanity-bit */
	*hps_ctrl &= ~MASK_29;

	/* calculate prescale-(xspc)-value:	[n   .. 1/2) : 1
						[1/2 .. 1/3) : 2
						[1/3 .. 1/4) : 3
						...		*/
	if (in_x > out_x) {
		xpsc = in_x / out_x;
	}
	else {
		/* zooming */
		xpsc = 1;
	}

	/* if flip_lr-bit is set, number of pixels after
	   horizontal prescaling must be < 384 */
	if ( 0 != flip_lr ) {

		/* set vanity bit */
		*hps_ctrl |= MASK_29;

		while (in_x / xpsc >= 384 )
			xpsc++;
	}
	/* if zooming is wanted, number of pixels after
	   horizontal prescaling must be < 768 */
	else {
		while ( in_x / xpsc >= 768 )
			xpsc++;
	}

	/* maximum prescale is 64 (p.69) */
	if ( xpsc >