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Commit 0df20f96 authored by Archit Taneja's avatar Archit Taneja Committed by Mauro Carvalho Chehab
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[media] v4l: ti-vpe: support loading of scaler coefficients 



The SC block in VPE/VIP contains a SRAM within it. This internal memory
requires to be loaded with appropriate scaler coefficients from a contiguous
block of memory through VPDMA.

The horizontal and vertical scaler each require 2 sets of scaler coefficients
for luma and chroma scaling. The horizontal polyphase scaler requires
coefficients for a 32 phase and 8 tap filter. Similarly, the vertical scaler
requires coefficients for a 5 tap filter.

The choice of the scaler coefficients depends on the scaling ratio. Add
coefficient tables for different scaling ratios in sc_coeffs.h. In the case of
horizontal downscaling, we need to consider the change in ratio caused by
decimation performed by the horizontal scaler.

In order to load the scaler coefficients via VPDMA, a configuration descriptor
is used in block mode. The payload for the descriptor is the scaler coefficients
copied to memory. Coefficients for each phase have to be placed in memory in a
particular order understood by the scaler hardware.

The choice of the scaler coefficients, and the loading of the coefficients from
our tables to a contiguous buffer is managed by the functions
sc_set_hs_coefficients and sc_set_vs_coefficients.

The sc_data handle is now added with some parameters to describe the state of
the coefficients loaded in the SC block. 'loaded_coeff_h' and 'loaded_coeff_v'
hold the address of the last dma buffer which was used by VPDMA to copy
coefficients. This information can be used by a vpe mem-to-mem context to decide
whether it should load coefficients or not. 'hs_index' and 'vs_index' provide
some optimization by preventing loading of coefficients if the scaling ratio
didn't change between 2 contexts. 'load_coeff_h' and 'load_coeff_v' tell the
vpe/vip driver whether we need to load the coefficients through VPDMA or not.

Signed-off-by: default avatarArchit Taneja <archit@ti.com>
Signed-off-by: default avatarHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: default avatarMauro Carvalho Chehab <m.chehab@samsung.com>
parent 44687b2e

drivers/media/platform/ti-vpe/sc.c

+98 −0
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ 
#include <linux/slab.h>



#include "sc.h"

#include "sc_coeff.h"



void sc_set_regs_bypass(struct sc_data *sc, u32 *sc_reg0)

{
@@ -61,6 +62,103 @@ void sc_dump_regs(struct sc_data *sc) 
#undef DUMPREG

}



/*

 * set the horizontal scaler coefficients according to the ratio of output to

 * input widths, after accounting for up to two levels of decimation

 */

void sc_set_hs_coeffs(struct sc_data *sc, void *addr, unsigned int src_w,

		unsigned int dst_w)

{

	int sixteenths;

	int idx;

	int i, j;

	u16 *coeff_h = addr;

	const u16 *cp;



	if (dst_w > src_w) {

		idx = HS_UP_SCALE;

	} else {

		if ((dst_w << 1) < src_w)

			dst_w <<= 1;	/* first level decimation */

		if ((dst_w << 1) < src_w)

			dst_w <<= 1;	/* second level decimation */



		if (dst_w == src_w) {

			idx = HS_LE_16_16_SCALE;

		} else {

			sixteenths = (dst_w << 4) / src_w;

			if (sixteenths < 8)

				sixteenths = 8;

			idx = HS_LT_9_16_SCALE + sixteenths - 8;

		}

	}



	if (idx == sc->hs_index)

		return;



	cp = scaler_hs_coeffs[idx];



	for (i = 0; i < SC_NUM_PHASES * 2; i++) {

		for (j = 0; j < SC_H_NUM_TAPS; j++)

			*coeff_h++ = *cp++;

		/*

		 * for each phase, the scaler expects space for 8 coefficients

		 * in it's memory. For the horizontal scaler, we copy the first

		 * 7 coefficients and skip the last slot to move to the next

		 * row to hold coefficients for the next phase

		 */

		coeff_h += SC_NUM_TAPS_MEM_ALIGN - SC_H_NUM_TAPS;

	}



	sc->hs_index = idx;



	sc->load_coeff_h = true;

}



/*

 * set the vertical scaler coefficients according to the ratio of output to

 * input heights

 */

void sc_set_vs_coeffs(struct sc_data *sc, void *addr, unsigned int src_h,

		unsigned int dst_h)

{

	int sixteenths;

	int idx;

	int i, j;

	u16 *coeff_v = addr;

	const u16 *cp;



	if (dst_h > src_h) {

		idx = VS_UP_SCALE;

	} else if (dst_h == src_h) {

		idx = VS_1_TO_1_SCALE;

	} else {

		sixteenths = (dst_h << 4) / src_h;

		if (sixteenths < 8)

			sixteenths = 8;

		idx = VS_LT_9_16_SCALE + sixteenths - 8;

	}



	if (idx == sc->vs_index)

		return;



	cp = scaler_vs_coeffs[idx];



	for (i = 0; i < SC_NUM_PHASES * 2; i++) {

		for (j = 0; j < SC_V_NUM_TAPS; j++)

			*coeff_v++ = *cp++;

		/*

		 * for the vertical scaler, we copy the first 5 coefficients and

		 * skip the last 3 slots to move to the next row to hold

		 * coefficients for the next phase

		 */

		coeff_v += SC_NUM_TAPS_MEM_ALIGN - SC_V_NUM_TAPS;

	}



	sc->vs_index = idx;

	sc->load_coeff_v = true;

}



struct sc_data *sc_create(struct platform_device *pdev)

{

	struct sc_data *sc;

drivers/media/platform/ti-vpe/sc.h

+31 −0
Original line number Diff line number Diff line
@@ -161,15 +161,46 @@ 
#define CFG_OFF_W_MASK			0x07ff

#define CFG_OFF_W_SHIFT			16



/* number of phases supported by the polyphase scalers */

#define SC_NUM_PHASES			32



/* number of taps used by horizontal polyphase scaler */

#define SC_H_NUM_TAPS			7



/* number of taps used by vertical polyphase scaler */

#define SC_V_NUM_TAPS			5



/* number of taps expected by the scaler in it's coefficient memory */

#define SC_NUM_TAPS_MEM_ALIGN		8



/*

 * coefficient memory size in bytes:

 * num phases x num sets(luma and chroma) x num taps(aligned) x coeff size

 */

#define SC_COEF_SRAM_SIZE	(SC_NUM_PHASES * 2 * SC_NUM_TAPS_MEM_ALIGN * 2)



struct sc_data {

	void __iomem		*base;

	struct resource		*res;



	dma_addr_t		loaded_coeff_h; /* loaded h coeffs in SC */

	dma_addr_t		loaded_coeff_v; /* loaded v coeffs in SC */



	bool			load_coeff_h;	/* have new h SC coeffs */

	bool			load_coeff_v;	/* have new v SC coeffs */



	unsigned int		hs_index;	/* h SC coeffs selector */

	unsigned int		vs_index;	/* v SC coeffs selector */



	struct platform_device *pdev;

};



void sc_set_regs_bypass(struct sc_data *sc, u32 *sc_reg0);

void sc_dump_regs(struct sc_data *sc);

void sc_set_hs_coeffs(struct sc_data *sc, void *addr, unsigned int src_w,

		unsigned int dst_w);

void sc_set_vs_coeffs(struct sc_data *sc, void *addr, unsigned int src_h,

		unsigned int dst_h);

struct sc_data *sc_create(struct platform_device *pdev);



#endif

drivers/media/platform/ti-vpe/sc_coeff.h

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