Re: [PATCH v2 2/2] drm: mali-dp: enable gamma support

[Liviu Dudau]

On Wed, Feb 01, 2017 at 02:48:50PM +0000, Mihail Atanassov wrote:
> Add gamma via the DRM GAMMA_LUT/GAMMA_LUT_SIZE CRTC
> properties. The expected LUT size is 4096 in order
> to produce as accurate a set of segments as possible.
> 
> This version uses only the green channel's gamma curve
> to set the hardware curve on DP550/650. For the sake of
> simplicity, it uses the same table of coefficients for
> all 3 curves on DP500.
> 
> Signed-off-by: Mihail Atanassov <mihail.atanassov@xxxxxxx>
> Reviewed-by: Brian Starkey <brian.starkey@xxxxxxx>

For the whole series:

Acked-by: Liviu Dudau <liviu.dudau@xxxxxxx>

Thanks,
Liviu

> ---
>  drivers/gpu/drm/arm/malidp_crtc.c | 132 ++++++++++++++++++++++++++++++++++++--
>  drivers/gpu/drm/arm/malidp_drv.c  |  52 +++++++++++++++
>  drivers/gpu/drm/arm/malidp_drv.h  |   1 +
>  drivers/gpu/drm/arm/malidp_hw.c   |   3 +
>  drivers/gpu/drm/arm/malidp_hw.h   |   2 +
>  drivers/gpu/drm/arm/malidp_regs.h |  19 ++++--
>  6 files changed, 199 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/gpu/drm/arm/malidp_crtc.c b/drivers/gpu/drm/arm/malidp_crtc.c
> index ebf57e6..10f79b6 100644
> --- a/drivers/gpu/drm/arm/malidp_crtc.c
> +++ b/drivers/gpu/drm/arm/malidp_crtc.c
> @@ -82,6 +82,114 @@ static void malidp_crtc_disable(struct drm_crtc *crtc)
>  	clk_disable_unprepare(hwdev->pxlclk);
>  }
>  
> +static const struct gamma_curve_segment {
> +	u16 start;
> +	u16 end;
> +} segments[MALIDP_COEFFTAB_NUM_COEFFS] = {
> +	/* sector 0 */
> +	{    0,    0 }, {    1,    1 }, {    2,    2 }, {    3,    3 },
> +	{    4,    4 }, {    5,    5 }, {    6,    6 }, {    7,    7 },
> +	{    8,    8 }, {    9,    9 }, {   10,   10 }, {   11,   11 },
> +	{   12,   12 }, {   13,   13 }, {   14,   14 }, {   15,   15 },
> +	/* sector 1 */
> +	{   16,   19 }, {   20,   23 }, {   24,   27 }, {   28,   31 },
> +	/* sector 2 */
> +	{   32,   39 }, {   40,   47 }, {   48,   55 }, {   56,   63 },
> +	/* sector 3 */
> +	{   64,   79 }, {   80,   95 }, {   96,  111 }, {  112,  127 },
> +	/* sector 4 */
> +	{  128,  159 }, {  160,  191 }, {  192,  223 }, {  224,  255 },
> +	/* sector 5 */
> +	{  256,  319 }, {  320,  383 }, {  384,  447 }, {  448,  511 },
> +	/* sector 6 */
> +	{  512,  639 }, {  640,  767 }, {  768,  895 }, {  896, 1023 },
> +	{ 1024, 1151 }, { 1152, 1279 }, { 1280, 1407 }, { 1408, 1535 },
> +	{ 1536, 1663 }, { 1664, 1791 }, { 1792, 1919 }, { 1920, 2047 },
> +	{ 2048, 2175 }, { 2176, 2303 }, { 2304, 2431 }, { 2432, 2559 },
> +	{ 2560, 2687 }, { 2688, 2815 }, { 2816, 2943 }, { 2944, 3071 },
> +	{ 3072, 3199 }, { 3200, 3327 }, { 3328, 3455 }, { 3456, 3583 },
> +	{ 3584, 3711 }, { 3712, 3839 }, { 3840, 3967 }, { 3968, 4095 },
> +};
> +
> +#define DE_COEFTAB_DATA(a, b) ((((a) & 0xfff) << 16) | (((b) & 0xfff)))
> +
> +static void malidp_generate_gamma_table(struct drm_property_blob *lut_blob,
> +					u32 coeffs[MALIDP_COEFFTAB_NUM_COEFFS])
> +{
> +	struct drm_color_lut *lut = (struct drm_color_lut *)lut_blob->data;
> +	int i;
> +
> +	for (i = 0; i < MALIDP_COEFFTAB_NUM_COEFFS; ++i) {
> +		u32 a, b;
> +		u32 delta_in;
> +		u32 out_start, out_end;
> +
> +		delta_in = segments[i].end - segments[i].start;
> +		/* DP has 12-bit internal precision for its LUTs. */
> +		out_start = drm_color_lut_extract(lut[segments[i].start].green,
> +						  12);
> +		out_end = drm_color_lut_extract(lut[segments[i].end].green, 12);
> +		a = (delta_in == 0) ?
> +		    0 : ((out_end - out_start) * 256) / delta_in;
> +		b = out_start;
> +		coeffs[i] = DE_COEFTAB_DATA(a, b);
> +	}
> +}
> +
> +/*
> + * Check if there is a new gamma LUT and if it is of an acceptable size. Also,
> + * reject any LUTs that use distinct red, green, and blue curves.
> + */
> +static int malidp_crtc_atomic_check_gamma(struct drm_crtc *crtc,
> +					  struct drm_crtc_state *state)
> +{
> +	struct malidp_crtc_state *mc = to_malidp_crtc_state(state);
> +	struct drm_color_lut *lut;
> +	size_t lut_size;
> +	int i;
> +
> +	if (!state->color_mgmt_changed)
> +		return 0;
> +
> +	if (!state->gamma_lut)
> +		return 0;
> +
> +	if (crtc->state->gamma_lut && (crtc->state->gamma_lut->base.id ==
> +				       state->gamma_lut->base.id))
> +		return 0;
> +
> +	if (state->gamma_lut->length % sizeof(struct drm_color_lut))
> +		return -EINVAL;
> +
> +	lut_size = state->gamma_lut->length / sizeof(struct drm_color_lut);
> +	if (lut_size != 4096)
> +		return -EINVAL;
> +
> +	lut = (struct drm_color_lut *)state->gamma_lut->data;
> +	for (i = 0; i < lut_size; ++i)
> +		if (!((lut[i].red == lut[i].green) &&
> +		      (lut[i].red == lut[i].blue)))
> +			return -EINVAL;
> +
> +	if (!state->mode_changed) {
> +		int ret;
> +
> +		state->mode_changed = true;
> +		/*
> +		 * Kerneldoc for drm_atomic_helper_check_modeset mandates that
> +		 * it be invoked when the driver sets ->mode_changed. Since
> +		 * changing the gamma LUT Doesn't depend on any external
> +		 * resources, it is safe to call it only once.
> +		 */
> +		ret = drm_atomic_helper_check_modeset(crtc->dev, state->state);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	malidp_generate_gamma_table(state->gamma_lut, mc->gamma_coeffs);
> +	return 0;
> +}
> +
>  static int malidp_crtc_atomic_check(struct drm_crtc *crtc,
>  				    struct drm_crtc_state *state)
>  {
> @@ -91,6 +199,7 @@ static int malidp_crtc_atomic_check(struct drm_crtc *crtc,
>  	const struct drm_plane_state *pstate;
>  	u32 rot_mem_free, rot_mem_usable;
>  	int rotated_planes = 0;
> +	int ret;
>  
>  	/*
>  	 * check if there is enough rotation memory available for planes
> @@ -157,21 +266,29 @@ static int malidp_crtc_atomic_check(struct drm_crtc *crtc,
>  		}
>  	}
>  
> +	ret = malidp_crtc_atomic_check_gamma(crtc, state);
> +	if (ret)
> +		return ret;
> +
>  	return 0;
>  }
>  
>  static struct drm_crtc_state *malidp_crtc_duplicate_state(struct drm_crtc *crtc)
>  {
> +	struct malidp_crtc_state *cs;
>  	struct malidp_crtc_state *state;
>  
>  	if (WARN_ON(!crtc->state))
>  		return NULL;
>  
> +	cs = to_malidp_crtc_state(crtc->state);
>  	state = kmalloc(sizeof(*state), GFP_KERNEL);
>  	if (!state)
>  		return NULL;
>  
>  	__drm_atomic_helper_crtc_duplicate_state(crtc, &state->base);
> +	memcpy(state->gamma_coeffs, cs->gamma_coeffs,
> +	       sizeof(state->gamma_coeffs));
>  
>  	return &state->base;
>  }
> @@ -201,6 +318,7 @@ static void malidp_crtc_reset(struct drm_crtc *crtc)
>  };
>  
>  static const struct drm_crtc_funcs malidp_crtc_funcs = {
> +	.gamma_set = drm_atomic_helper_legacy_gamma_set,
>  	.destroy = drm_crtc_cleanup,
>  	.set_config = drm_atomic_helper_set_config,
>  	.page_flip = drm_atomic_helper_page_flip,
> @@ -236,11 +354,17 @@ int malidp_crtc_init(struct drm_device *drm)
>  
>  	ret = drm_crtc_init_with_planes(drm, &malidp->crtc, primary, NULL,
>  					&malidp_crtc_funcs, NULL);
> +	if (ret)
> +		goto crtc_cleanup_planes;
>  
> -	if (!ret) {
> -		drm_crtc_helper_add(&malidp->crtc, &malidp_crtc_helper_funcs);
> -		return 0;
> -	}
> +	drm_crtc_helper_add(&malidp->crtc, &malidp_crtc_helper_funcs);
> +	drm_mode_crtc_set_gamma_size(&malidp->crtc, 4096);
> +	/* No inverse-gamma and color adjustments yet. */
> +	drm_crtc_enable_color_mgmt(&malidp->crtc,
> +				   0,
> +				   false,
> +				   4096);
> +	return 0;
>  
>  crtc_cleanup_planes:
>  	malidp_de_planes_destroy(drm);
> diff --git a/drivers/gpu/drm/arm/malidp_drv.c b/drivers/gpu/drm/arm/malidp_drv.c
> index 32f746e..a9f787d 100644
> --- a/drivers/gpu/drm/arm/malidp_drv.c
> +++ b/drivers/gpu/drm/arm/malidp_drv.c
> @@ -33,6 +33,51 @@
>  
>  #define MALIDP_CONF_VALID_TIMEOUT	250
>  
> +static void malidp_write_gamma_table(struct malidp_hw_device *hwdev,
> +				     u32 data[MALIDP_COEFFTAB_NUM_COEFFS])
> +{
> +	int i;
> +	/* Update all channels with a single gamma curve. */
> +	const u32 gamma_write_mask = GENMASK(18, 16);
> +	/*
> +	 * Always write an entire table, so the address field in
> +	 * DE_COEFFTAB_ADDR is 0 and we can use the gamma_write_mask bitmask
> +	 * directly.
> +	 */
> +	malidp_hw_write(hwdev, gamma_write_mask,
> +			hwdev->map.coeffs_base + MALIDP_COEF_TABLE_ADDR);
> +	for (i = 0; i < MALIDP_COEFFTAB_NUM_COEFFS; ++i)
> +		malidp_hw_write(hwdev, data[i],
> +				hwdev->map.coeffs_base +
> +				MALIDP_COEF_TABLE_DATA);
> +}
> +
> +static void malidp_atomic_commit_update_gamma(struct drm_crtc *crtc,
> +					      struct drm_crtc_state *old_state)
> +{
> +	struct malidp_drm *malidp = crtc_to_malidp_device(crtc);
> +	struct malidp_hw_device *hwdev = malidp->dev;
> +
> +	if (!crtc->state->color_mgmt_changed)
> +		return;
> +
> +	if (!crtc->state->gamma_lut) {
> +		malidp_hw_clearbits(hwdev,
> +				    MALIDP_DISP_FUNC_GAM,
> +				    MALIDP_DE_DISPLAY_FUNC);
> +	} else {
> +		struct malidp_crtc_state *mc =
> +			to_malidp_crtc_state(crtc->state);
> +
> +		if (!old_state->gamma_lut || (crtc->state->gamma_lut->base.id !=
> +					      old_state->gamma_lut->base.id))
> +			malidp_write_gamma_table(hwdev, mc->gamma_coeffs);
> +
> +		malidp_hw_setbits(hwdev, MALIDP_DISP_FUNC_GAM,
> +				  MALIDP_DE_DISPLAY_FUNC);
> +	}
> +}
> +
>  /*
>   * set the "config valid" bit and wait until the hardware acts on it
>   */
> @@ -89,8 +134,15 @@ static void malidp_atomic_commit_hw_done(struct drm_atomic_state *state)
>  static void malidp_atomic_commit_tail(struct drm_atomic_state *state)
>  {
>  	struct drm_device *drm = state->dev;
> +	struct drm_crtc *crtc;
> +	struct drm_crtc_state *old_crtc_state;
> +	int i;
>  
>  	drm_atomic_helper_commit_modeset_disables(drm, state);
> +
> +	for_each_crtc_in_state(state, crtc, old_crtc_state, i)
> +		malidp_atomic_commit_update_gamma(crtc, old_crtc_state);
> +
>  	drm_atomic_helper_commit_modeset_enables(drm, state);
>  	drm_atomic_helper_commit_planes(drm, state, 0);
>  
> diff --git a/drivers/gpu/drm/arm/malidp_drv.h b/drivers/gpu/drm/arm/malidp_drv.h
> index c7a69ae..374d43e 100644
> --- a/drivers/gpu/drm/arm/malidp_drv.h
> +++ b/drivers/gpu/drm/arm/malidp_drv.h
> @@ -49,6 +49,7 @@ struct malidp_plane_state {
>  
>  struct malidp_crtc_state {
>  	struct drm_crtc_state base;
> +	u32 gamma_coeffs[MALIDP_COEFFTAB_NUM_COEFFS];
>  };
>  
>  #define to_malidp_crtc_state(x) container_of(x, struct malidp_crtc_state, base)
> diff --git a/drivers/gpu/drm/arm/malidp_hw.c b/drivers/gpu/drm/arm/malidp_hw.c
> index 4bdf531..5ceca17 100644
> --- a/drivers/gpu/drm/arm/malidp_hw.c
> +++ b/drivers/gpu/drm/arm/malidp_hw.c
> @@ -415,6 +415,7 @@ static int malidp650_query_hw(struct malidp_hw_device *hwdev)
>  const struct malidp_hw_device malidp_device[MALIDP_MAX_DEVICES] = {
>  	[MALIDP_500] = {
>  		.map = {
> +			.coeffs_base = MALIDP500_COEFFS_BASE,
>  			.se_base = MALIDP500_SE_BASE,
>  			.dc_base = MALIDP500_DC_BASE,
>  			.out_depth_base = MALIDP500_OUTPUT_DEPTH,
> @@ -450,6 +451,7 @@ static int malidp650_query_hw(struct malidp_hw_device *hwdev)
>  	},
>  	[MALIDP_550] = {
>  		.map = {
> +			.coeffs_base = MALIDP550_COEFFS_BASE,
>  			.se_base = MALIDP550_SE_BASE,
>  			.dc_base = MALIDP550_DC_BASE,
>  			.out_depth_base = MALIDP550_DE_OUTPUT_DEPTH,
> @@ -483,6 +485,7 @@ static int malidp650_query_hw(struct malidp_hw_device *hwdev)
>  	},
>  	[MALIDP_650] = {
>  		.map = {
> +			.coeffs_base = MALIDP550_COEFFS_BASE,
>  			.se_base = MALIDP550_SE_BASE,
>  			.dc_base = MALIDP550_DC_BASE,
>  			.out_depth_base = MALIDP550_DE_OUTPUT_DEPTH,
> diff --git a/drivers/gpu/drm/arm/malidp_hw.h b/drivers/gpu/drm/arm/malidp_hw.h
> index 087e1202..ecff7d4 100644
> --- a/drivers/gpu/drm/arm/malidp_hw.h
> +++ b/drivers/gpu/drm/arm/malidp_hw.h
> @@ -66,6 +66,8 @@ struct malidp_layer {
>  struct malidp_hw_regmap {
>  	/* address offset of the DE register bank */
>  	/* is always 0x0000 */
> +	/* address offset of the DE coefficients registers */
> +	const u16 coeffs_base;
>  	/* address offset of the SE registers bank */
>  	const u16 se_base;
>  	/* address offset of the DC registers bank */
> diff --git a/drivers/gpu/drm/arm/malidp_regs.h b/drivers/gpu/drm/arm/malidp_regs.h
> index 73fecb3..2e213c3 100644
> --- a/drivers/gpu/drm/arm/malidp_regs.h
> +++ b/drivers/gpu/drm/arm/malidp_regs.h
> @@ -63,6 +63,7 @@
>  
>  /* bit masks that are common between products */
>  #define   MALIDP_CFG_VALID		(1 << 0)
> +#define   MALIDP_DISP_FUNC_GAM		(1 << 0)
>  #define   MALIDP_DISP_FUNC_ILACED	(1 << 8)
>  
>  /* register offsets for IRQ management */
> @@ -92,6 +93,12 @@
>  #define MALIDP_DE_H_ACTIVE(x)		(((x) & 0x1fff) << 0)
>  #define MALIDP_DE_V_ACTIVE(x)		(((x) & 0x1fff) << 16)
>  
> +#define MALIDP_COEFFTAB_NUM_COEFFS	64
> +/* register offsets relative to MALIDP5x0_COEFFS_BASE */
> +#define MALIDP_COLOR_ADJ_COEF		0x00000
> +#define MALIDP_COEF_TABLE_ADDR		0x00030
> +#define MALIDP_COEF_TABLE_DATA		0x00034
> +
>  /* register offsets and bits specific to DP500 */
>  #define MALIDP500_DC_BASE		0x00000
>  #define MALIDP500_DC_CONTROL		0x0000c
> @@ -109,9 +116,11 @@
>  #define MALIDP500_BGND_COLOR		0x0003c
>  #define MALIDP500_OUTPUT_DEPTH		0x00044
>  #define MALIDP500_YUV_RGB_COEF		0x00048
> -#define MALIDP500_COLOR_ADJ_COEF	0x00078
> -#define MALIDP500_COEF_TABLE_ADDR	0x000a8
> -#define MALIDP500_COEF_TABLE_DATA	0x000ac
> +/*
> + * To match DP550/650, the start of the coeffs registers is
> + * at COLORADJ_COEFF0 instead of at YUV_RGB_COEF1.
> + */
> +#define MALIDP500_COEFFS_BASE		0x00078
>  #define MALIDP500_DE_LV_BASE		0x00100
>  #define MALIDP500_DE_LV_PTR_BASE	0x00124
>  #define MALIDP500_DE_LG1_BASE		0x00200
> @@ -136,9 +145,7 @@
>  #define MALIDP550_DE_DISP_SIDEBAND	0x00040
>  #define MALIDP550_DE_BGND_COLOR		0x00044
>  #define MALIDP550_DE_OUTPUT_DEPTH	0x0004c
> -#define MALIDP550_DE_COLOR_COEF		0x00050
> -#define MALIDP550_DE_COEF_TABLE_ADDR	0x00080
> -#define MALIDP550_DE_COEF_TABLE_DATA	0x00084
> +#define MALIDP550_COEFFS_BASE		0x00050
>  #define MALIDP550_DE_LV1_BASE		0x00100
>  #define MALIDP550_DE_LV1_PTR_BASE	0x00124
>  #define MALIDP550_DE_LV2_BASE		0x00200
> -- 
> 1.9.1
> 

-- 
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| but they're not |
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