[PATCH v2 09/10] media: adv748x: add support for log_status ioctl

[Alex Riesen <alexander.riesen@cetitec.com>]

The logged information provides insights about cable connection and the
state of the HDMI decoder. It is very useful when debugging hardware
problems in environments without easy access to the connectors.

This change adds a device-specific wrapper for register block read,
because some of the devices I2C-accessible registers (for instance,
cs_data for stereo channel information or tmds_params for TMDS channel
information) located in adjacent cells. According to manufacturers
information, these registers can be read using block transactions.

Signed-off-by: Alexander Riesen <alexander.riesen@cetitec.com>
---
 drivers/media/i2c/adv748x/adv748x-core.c |  15 ++
 drivers/media/i2c/adv748x/adv748x-hdmi.c | 179 +++++++++++++++++++++++
 drivers/media/i2c/adv748x/adv748x.h      |   2 +
 3 files changed, 196 insertions(+)

diff --git a/drivers/media/i2c/adv748x/adv748x-core.c b/drivers/media/i2c/adv748x/adv748x-core.c
index 2c0bd58038e6..fbc502ad12b5 100644
--- a/drivers/media/i2c/adv748x/adv748x-core.c
+++ b/drivers/media/i2c/adv748x/adv748x-core.c
@@ -95,6 +95,21 @@ static const struct adv748x_register_map adv748x_default_addresses[] = {
 	[ADV748X_PAGE_TXA] = { "txa", 0x4a },
 };
 
+int adv748x_read_block(struct adv748x_state *state, u8 client_page, u8 reg,
+		       void *val, size_t reg_count)
+{
+	struct i2c_client *client = state->i2c_clients[client_page];
+	int err;
+
+	err = regmap_bulk_read(state->regmap[client_page], reg, val, reg_count);
+	if (err) {
+		adv_err(state, "error reading %02x, %02x-%02lx: %d\n",
+				client->addr, reg, reg + reg_count - 1, err);
+		return err;
+	}
+	return 0;
+}
+
 static int adv748x_read_check(struct adv748x_state *state,
 			      int client_page, u8 reg)
 {
diff --git a/drivers/media/i2c/adv748x/adv748x-hdmi.c b/drivers/media/i2c/adv748x/adv748x-hdmi.c
index 0dffcdf79ff2..7655d817ceb6 100644
--- a/drivers/media/i2c/adv748x/adv748x-hdmi.c
+++ b/drivers/media/i2c/adv748x/adv748x-hdmi.c
@@ -5,6 +5,7 @@
  * Copyright (C) 2017 Renesas Electronics Corp.
  */
 
+#include <linux/version.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
 
@@ -601,11 +602,189 @@ static const struct v4l2_subdev_pad_ops adv748x_pad_ops_hdmi = {
 	.enum_dv_timings = adv748x_hdmi_enum_dv_timings,
 };
 
+struct tmds_params {
+	u32 cts, n;
+	u16 tmdsfreq, tmdsfreq_frac;
+};
+
+static inline const char *cs_data_smpl_freq_str(u8 cs_data_3)
+{
+	switch (cs_data_3 & 0xf) {
+	case 0:
+		return "44.1";
+	case 2:
+		return "48";
+	case 3:
+		return "32";
+	case 8:
+		return "88.2";
+	case 10:
+		return "96";
+	case 12:
+		return "176";
+	case 14:
+		return "192";
+	}
+	return "reserved";
+}
+
+static inline const char *cs_data_clk_lvl_str(u8 cs_data_3)
+{
+	switch (cs_data_3 & 0x30) {
+	case 0:
+		return "Level II";
+	case 1:
+		return "Level I";
+	case 2:
+		return "Level III, variable pitch shifted";
+	}
+	return "reserved";
+}
+
+static inline const char *i2s_out_mode_str(u8 i2s_mode)
+{
+	switch (i2s_mode & ADV748X_HDMI_I2SOUTMODE_MASK) {
+	case 0 << ADV748X_HDMI_I2SOUTMODE_SHIFT:
+		return "I2S";
+	case 1 << ADV748X_HDMI_I2SOUTMODE_SHIFT:
+		return "right";
+	case 2 << ADV748X_HDMI_I2SOUTMODE_SHIFT:
+		return "left";
+	case 3 << ADV748X_HDMI_I2SOUTMODE_SHIFT:
+		return "spdif";
+	}
+	return "";
+}
+
+static int adv748x_hdmi_log_status(struct v4l2_subdev *sd)
+{
+	struct adv748x_hdmi *hdmi = adv748x_sd_to_hdmi(sd);
+	struct adv748x_state *state = adv748x_hdmi_to_state(hdmi);
+	u8 rv, i2s_tdm_mode_enable;
+	u8 cts_n[5];
+	u8 cs_data[0x3a - 0x36 + 1];
+	u8 tmdsfreq[2]; /* both tmdsfreq and tmdsfreq_frac */
+	struct tmds_params tmds_params;
+
+	/* Audio control and configuration */
+	rv = io_read(state, 0x71);
+	pr_info("cable_det_a_raw         %s\n",
+		rv & BIT(6) ? "detected" : "no cable");
+	pr_info("tmds_clk_a_raw          %s\n",
+		rv & BIT(3) ? "detected" : "no TMDS clock");
+	pr_info("tmdspll_lck_a_raw       %s\n",
+		rv & BIT(7) ? "locked to incoming clock" : "not locked");
+	pr_info("hdmi_encrpt_a_raw       %s\n",
+		rv & BIT(5) ? "current frame encrypted" : "not encrypted");
+	rv = hdmi_read(state, 0x04);
+	pr_info("audio_pll_locked        0x%02lx\n", rv & BIT(0));
+	pr_info("tmds_pll_locked         0x%02lx\n", rv & BIT(1));
+	rv = io_read(state, 0x6c);
+	pr_info("gamut_mdata_raw         %s\n",
+		rv & BIT(0) ? "received" : "-");
+	pr_info("audio_c_pckt_raw        %s\n",
+		rv & BIT(1) ? "ACR received" : "-");
+	pr_info("gen_ctl_pckt_raw        %s\n",
+		rv & BIT(2) ? "received" : "-");
+	pr_info("hdmi_mode_raw           %s\n",
+		rv & BIT(3) ? "HDMI/MHL" : "-");
+	pr_info("audio_ch_md_raw         %s\n",
+		rv & BIT(4) ? "multichannel" : "-");
+	pr_info("av_mute_raw             %s\n",
+		rv & BIT(5) ? "received" : "-");
+	pr_info("internal_mute_raw       %s\n",
+		rv & BIT(6) ? "asserted" : "-");
+	pr_info("cs_data_valid_raw       %s\n",
+		rv & BIT(7) ? "valid" : "-");
+	rv = hdmi_read(state, 0x6d);
+	pr_info("i2s_tdm_mode_enable     %s\n",
+		rv & BIT(7) ? "TDM (multichannel)" : "I2S (stereo)");
+	i2s_tdm_mode_enable = rv & BIT(7);
+
+	/* i2s_tdm_mode_enable must be unset */
+	if (adv748x_read_block(state, ADV748X_PAGE_HDMI, 0x36,
+			       cs_data, ARRAY_SIZE(cs_data)) == 0) {
+		pr_info("... cs_data %s\n",
+			cs_data[0] & BIT(0) ? "pro" : "consumer");
+		pr_info("... cs_data %s\n",
+			cs_data[0] & BIT(1) ? "other" : "L-PCM");
+		pr_info("... cs_data %s copyright\n",
+			cs_data[0] & BIT(2) ? "no" : "asserted");
+		pr_info("... cs_data %s (%lu)\n",
+			cs_data[0] & GENMASK(5, 3) ?
+			"50/15" : "no pre-emphasis",
+			(cs_data[0] & GENMASK(5, 3)) >> 4);
+		pr_info("... cs_data channels status mode %lu\n",
+			(cs_data[0] & GENMASK(7, 6)) >> 7);
+		pr_info("... cs_data category code 0x%02x\n", cs_data[1]);
+		pr_info("... cs_data source number %u\n", cs_data[2] & 0xf);
+		pr_info("... cs_data channel number %u\n",
+			(cs_data[2] & 0xf0) >> 4);
+		pr_info("... cs_data sampling frequency %s (%u)\n",
+			cs_data_smpl_freq_str(cs_data[3]), cs_data[3] & 0xf);
+		pr_info("... cs_data clock accuracy %s\n",
+			cs_data_clk_lvl_str(cs_data[3]));
+	}
+	rv = hdmi_read(state, ADV748X_HDMI_I2S);
+	pr_info("i2soutmode              %s\n", i2s_out_mode_str(rv));
+	pr_info("i2sbitwidth             %u\n", rv & 0x1fu);
+	rv = hdmi_read(state, 0x05);
+	pr_info("hdmi_mode               %s\n", rv & BIT(7) ? "HDMI" : "DVI");
+	rv = hdmi_read(state, 0x07);
+	pr_info("audio_channel_mode      %s\n",
+		rv & BIT(6) ? "multichannel" : "stereo or compressed");
+	rv = hdmi_read(state, 0x0f);
+	/* The bits 6 and 7 must be 1 if TDM mode */
+	pr_info("man_audio_dl_bypass     0x%02lx\n", rv & BIT(7));
+	pr_info("audio_delay_line_bypass 0x%02lx\n", rv & BIT(6));
+	rv = hdmi_read(state, 0x6e);
+	pr_info("mux_spdif_to_i2s_enable %s\n", rv & BIT(3) ? "SPDIF" : "I2S");
+	rv = dpll_read(state, ADV748X_DPLL_MCLK_FS);
+	pr_info("mclk_fs_n               %lu\n",
+		((rv & ADV748X_DPLL_MCLK_FS_N_MASK) + 1) * 128);
+
+	/* i2s_tdm_mode_enable must be set */
+	memset(&tmds_params, 0, sizeof(tmds_params));
+	if (adv748x_read_block(state, ADV748X_PAGE_HDMI, 0x5b, cts_n, 5) == 0) {
+		tmds_params.cts  = cts_n[0] << 12;
+		tmds_params.cts |= cts_n[1] << 4;
+		tmds_params.cts |= cts_n[2] >> 4;
+		tmds_params.n  = (cts_n[2] & 0xf) << 16;
+		tmds_params.n |= cts_n[3] << 8;
+		tmds_params.n |= cts_n[4];
+		pr_info("... TDM: ACR cts  %u\n", tmds_params.cts);
+		pr_info("... TDM: ACR n    %u\n", tmds_params.n);
+	}
+	if (adv748x_read_block(state, ADV748X_PAGE_HDMI, 0x51,
+			       tmdsfreq, 2) == 0) {
+		tmds_params.tmdsfreq  = tmdsfreq[0] << 1;
+		tmds_params.tmdsfreq |= tmdsfreq[1] >> 7;
+		tmds_params.tmdsfreq_frac = tmdsfreq[1] & 0x7f;
+		pr_info("... TDM: tmdsfreq       %d MHz\n",
+			tmds_params.tmdsfreq);
+		pr_info("... TDM: tmdsfreq_frac  %d 1/128\n",
+			tmds_params.tmdsfreq_frac);
+	}
+	if (i2s_tdm_mode_enable)
+		pr_info("... TDM: sampling frequency %u Hz\n",
+			tmds_params.cts ?
+			(tmds_params.tmdsfreq * tmds_params.n +
+			 tmds_params.tmdsfreq_frac * tmds_params.n / 128) *
+			1000 / (128 * tmds_params.cts / 1000) :
+			UINT_MAX);
+	return 0;
+}
+
+static const struct v4l2_subdev_core_ops adv748x_core_ops_hdmi = {
+	.log_status = adv748x_hdmi_log_status,
+};
+
 /* -----------------------------------------------------------------------------
  * v4l2_subdev_ops
  */
 
 static const struct v4l2_subdev_ops adv748x_ops_hdmi = {
+	.core = &adv748x_core_ops_hdmi,
 	.video = &adv748x_video_ops_hdmi,
 	.pad = &adv748x_pad_ops_hdmi,
 };
diff --git a/drivers/media/i2c/adv748x/adv748x.h b/drivers/media/i2c/adv748x/adv748x.h
index af70632926b5..3ce7ae7f2ec5 100644
--- a/drivers/media/i2c/adv748x/adv748x.h
+++ b/drivers/media/i2c/adv748x/adv748x.h
@@ -432,6 +432,8 @@ struct adv748x_state {
 /* Register handling */
 
 int adv748x_read(struct adv748x_state *state, u8 addr, u8 reg);
+int adv748x_read_block(struct adv748x_state *state, u8 page, u8 reg,
+		       void *val, size_t reg_count);
 int adv748x_write(struct adv748x_state *state, u8 page, u8 reg, u8 value);
 int adv748x_write_block(struct adv748x_state *state, int client_page,
 			unsigned int init_reg, const void *val,
-- 
2.25.1.25.g9ecbe7eb18