[PATCH v7 07/18] media: rppx1: Add support for Auto Exposure Measurement

[Jai Luthra]

From: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>

Extend the RPPX1 driver to allow setting the EXM configuration using the
parameter buffer format. It uses the RPPX1 framework for parameters and
its writer abstraction to allow the user to control how (and when)
configuration is applied to the RPPX1.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>
Signed-off-by: Jai Luthra <jai.luthra+renesas@xxxxxxxxxxxxxxxx>
---
 .../media/platform/dreamchip/rppx1/rpp_params.c    |  4 ++
 drivers/media/platform/dreamchip/rppx1/rpp_stats.c |  4 ++
 drivers/media/platform/dreamchip/rppx1/rppx1_exm.c | 82 ++++++++++++++++++++++
 3 files changed, 90 insertions(+)

diff --git a/drivers/media/platform/dreamchip/rppx1/rpp_params.c b/drivers/media/platform/dreamchip/rppx1/rpp_params.c
index de47be81133d067a85f63ba0eb3f8f5e1f0ba2d3..928e4fa196c0e4c0db6a23a89833359645a0941e 100644
--- a/drivers/media/platform/dreamchip/rppx1/rpp_params.c
+++ b/drivers/media/platform/dreamchip/rppx1/rpp_params.c
@@ -18,6 +18,7 @@ static const struct v4l2_isp_params_block_type_info
 rppx1_ext_params_blocks_info[] = {
 	RPPX1_PARAMS_BLOCK_INFO(AWB_GAIN, awb_gain),
 	RPPX1_PARAMS_BLOCK_INFO(AWB_MEAS, awb_meas),
+	RPPX1_PARAMS_BLOCK_INFO(AEC_MEAS, aec),
 };
 
 int rppx1_params(struct rppx1 *rpp, struct vb2_buffer *vb, size_t max_size,
@@ -58,6 +59,9 @@ int rppx1_params(struct rppx1 *rpp, struct vb2_buffer *vb, size_t max_size,
 		case RPPX1_PARAMS_BLOCK_TYPE_AWB_MEAS:
 			module = &rpp->post.wbmeas;
 			break;
+		case RPPX1_PARAMS_BLOCK_TYPE_AEC_MEAS:
+			module = &rpp->pre1.exm;
+			break;
 		default:
 			module = NULL;
 			break;
diff --git a/drivers/media/platform/dreamchip/rppx1/rpp_stats.c b/drivers/media/platform/dreamchip/rppx1/rpp_stats.c
index aac7692d2a61e919e32d7684af86f856ab5a22bb..44edcbc7f2b644d7d569d46707b0b4b94ebe4144 100644
--- a/drivers/media/platform/dreamchip/rppx1/rpp_stats.c
+++ b/drivers/media/platform/dreamchip/rppx1/rpp_stats.c
@@ -15,5 +15,9 @@ void rppx1_stats_fill_isr(struct rppx1 *rpp, u32 isc, void *buf)
 	if (isc & RPPX1_IRQ_ID_POST_AWB_MEAS)
 		if (!rpp_module_call(&rpp->post.wbmeas, fill_stats, &stats->params))
 			stats->meas_type |= RPPX1_STAT_AWB;
+
+	if (isc & RPPX1_IRQ_ID_PRE1_EXM)
+		if (!rpp_module_call(&rpp->pre1.exm, fill_stats, &stats->params))
+			stats->meas_type |= RPPX1_STAT_AUTOEXP;
 }
 EXPORT_SYMBOL_GPL(rppx1_stats_fill_isr);
diff --git a/drivers/media/platform/dreamchip/rppx1/rppx1_exm.c b/drivers/media/platform/dreamchip/rppx1/rppx1_exm.c
index 0c40300e13ad934c02106d804dd776990983792f..f756f7f882a124850a0908d9efa564443de01b2a 100644
--- a/drivers/media/platform/dreamchip/rppx1/rppx1_exm.c
+++ b/drivers/media/platform/dreamchip/rppx1/rppx1_exm.c
@@ -10,6 +10,7 @@
 #define EXM_START_REG			0x0004
 
 #define EXM_CTRL_REG			0x0008
+#define EXM_CTRL_EXM_AUTOSTOP		BIT(1) /* HW doc says not supported. */
 #define EXM_CTRL_EXM_UPDATE_ENABLE	BIT(0)
 
 #define EXM_MODE_REG			0x000c
@@ -46,6 +47,87 @@ static int rppx1_exm_probe(struct rpp_module *mod)
 	return 0;
 }
 
+static int
+rppx1_exm_fill_params(struct rpp_module *mod,
+		      const union rppx1_params_block *block,
+		      rppx1_reg_write write, void *priv)
+{
+	const struct rppx1_params_aec_config *cfg = &block->aec;
+	u32 h_offs, v_offs, h_size, v_size;
+
+	/* If the modules is disabled, simply bypass it. */
+	if (cfg->header.flags & V4L2_ISP_PARAMS_FL_BLOCK_DISABLE) {
+		write(priv, mod->base + EXM_MODE_REG, 0);
+		return 0;
+	}
+
+	/* RGB bayer exposure measurement */
+	write(priv, mod->base + EXM_MODE_REG, 2);
+
+	write(priv, mod->base + EXM_CTRL_REG, EXM_CTRL_EXM_UPDATE_ENABLE |
+	      cfg->autostop ? EXM_CTRL_EXM_AUTOSTOP : 0);
+
+	/*
+	 * Select where to sample.
+	 * 0 - after input acquisition
+	 * 1 - after black level subtraction
+	 * 2 - after input linearization
+	 * 3 - after lens shade correction
+	 * 4 - after white balance gain stage
+	 * 5 - after defect pixel correction
+	 * 6 - after denoising
+	 */
+	write(priv, mod->base + EXM_CHANNEL_SEL_REG, 6);
+
+	if (cfg->mode == RPPX1_EXP_MEASURING_MODE_0) {
+		/* Coefficients for a BT.601 BAYER (from datasheet). */
+		write(priv, mod->base + EXM_COEFF_R_REG, 38);
+		write(priv, mod->base + EXM_COEFF_G_GR_REG, 75);
+		write(priv, mod->base + EXM_COEFF_B_REG, 15);
+		write(priv, mod->base + EXM_COEFF_GB_REG, 75);
+	} else {
+		/* Y = (R + Gr + B + Gb) / 4*/
+		write(priv, mod->base + EXM_COEFF_R_REG, 128);
+		write(priv, mod->base + EXM_COEFF_G_GR_REG, 128);
+		write(priv, mod->base + EXM_COEFF_B_REG, 128);
+		write(priv, mod->base + EXM_COEFF_GB_REG, 128);
+	}
+
+	/*
+	 * Adjust and set measurement window to hardware limitations,
+	 * - Offsets must be even.
+	 * - Width and height must be divisible by 10.
+	 */
+	h_offs = cfg->meas_window.h_offs & 0x1ffe;
+	v_offs = cfg->meas_window.v_offs & 0x1ffe;
+	h_size = (cfg->meas_window.h_size - 1) - ((cfg->meas_window.h_size - 1) % 10);
+	v_size = (cfg->meas_window.v_size - 1) - ((cfg->meas_window.v_size - 1) % 10);
+
+	write(priv, mod->base + EXM_H_OFFS_REG, h_offs);
+	write(priv, mod->base + EXM_V_OFFS_REG, v_offs);
+	write(priv, mod->base + EXM_H_SIZE_REG, h_size / 5);
+	write(priv, mod->base + EXM_V_SIZE_REG, v_size / 5);
+
+	/* Set last measurement line for ready interrupt. */
+	write(priv, mod->base + EXM_LAST_MEAS_LINE_REG, v_offs + v_size + 1);
+
+	write(priv, mod->base + EXM_START_REG, 1);
+
+	return 0;
+}
+
+static int rppx1_exm_fill_stats(struct rpp_module *mod,
+				struct rppx1_stat *stats)
+{
+	/* Return measurements at native hardware precision. */
+	for (unsigned int i = 0; i < EXM_MEAN_REG_NUM; i++)
+		stats->ae.exp_mean[i] = rpp_module_read(mod, EXM_MEAN_REG(i));
+
+	return 0;
+}
+
 const struct rpp_module_ops rppx1_exm_ops = {
 	.probe = rppx1_exm_probe,
+	.fill_params = rppx1_exm_fill_params,
+	.fill_stats = rppx1_exm_fill_stats,
 };

-- 
2.53.0