drm/bridge: adv7511: Add Audio support

This patch adds support to Audio for both adv7511 and adv7533
bridge chips.

This patch was originally from [1] by Lars-Peter Clausen <[e-mail]>
and was adapted by Archit Taneja <[e-mail]> and
Srinivas Kandagatla <[e-mail]>.

Then I heavily reworked it to use the hdmi-codec driver. And also
folded in some audio packet initialization done by Andy Green
<[e-mail]>. So credit to them, but blame to me.

[1] https://github.com/analogdevicesinc/linux/blob/xcomm_zynq/drivers/gpu/drm/i2c/adv7511_audio.c

Cc: David Airlie <[e-mail]>
Cc: Archit Taneja <[e-mail]>
Cc: Laurent Pinchart <[e-mail]>
Cc: Wolfram Sang <[e-mail]>
Cc: Srinivas Kandagatla <[e-mail]>
Cc: "Ville Syrjälä" <[e-mail]>
Cc: Boris Brezillon <[e-mail]>
Cc: Andy Green <[e-mail]>
Cc: Dave Long <[e-mail]>
Cc: Guodong Xu <[e-mail]>
Cc: Zhangfei Gao <[e-mail]>
Cc: Mark Brown <[e-mail]>
Cc: Lars-Peter Clausen <[e-mail]>
Cc: Jose Abreu <[e-mail]>
Cc: Kuninori Morimoto <[e-mail]>
Cc: [e-mail]
Acked-by: Lars-Peter Clausen <[e-mail]>
Signed-off-by: John Stultz <[e-mail]>
Signed-off-by: Archit Taneja <[e-mail]>
Link: http://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/bridge/adv7511/Kconfig

···
 	help
 	  Support for the Analog Device ADV7511(W) and ADV7513 HDMI encoders.
 
+config DRM_I2C_ADV7511_AUDIO
+	bool "ADV7511 HDMI Audio driver"
+	depends on DRM_I2C_ADV7511 && SND_SOC
+	select SND_SOC_HDMI_CODEC
+	help
+	  Support the ADV7511 HDMI Audio interface. This is used in
+	  conjunction with the AV7511  HDMI driver.
+
 config DRM_I2C_ADV7533
 	bool "ADV7533 encoder"
 	depends on DRM_I2C_ADV7511

drivers/gpu/drm/bridge/adv7511/Makefile

···
 adv7511-y := adv7511_drv.o
+adv7511-$(CONFIG_DRM_I2C_ADV7511_AUDIO) += adv7511_audio.o
 adv7511-$(CONFIG_DRM_I2C_ADV7533) += adv7533.o
 obj-$(CONFIG_DRM_I2C_ADV7511) += adv7511.o

drivers/gpu/drm/bridge/adv7511/adv7511.h

···
 	struct drm_display_mode curr_mode;
 
 	unsigned int f_tmds;
+	unsigned int f_audio;
+	unsigned int audio_source;
 
 	unsigned int current_edid_segment;
 	uint8_t edid_buf[256];
···
 	bool use_timing_gen;
 
 	enum adv7511_type type;
+	struct platform_device *audio_pdev;
 };
 
 #ifdef CONFIG_DRM_I2C_ADV7533
···
 	return -ENODEV;
 }
 #endif
+
+#ifdef CONFIG_DRM_I2C_ADV7511_AUDIO
+int adv7511_audio_init(struct device *dev, struct adv7511 *adv7511);
+void adv7511_audio_exit(struct adv7511 *adv7511);
+#else /*CONFIG_DRM_I2C_ADV7511_AUDIO */
+static inline int adv7511_audio_init(struct device *dev, struct adv7511 *adv7511)
+{
+	return 0;
+}
+static inline void adv7511_audio_exit(struct adv7511 *adv7511)
+{
+}
+#endif /* CONFIG_DRM_I2C_ADV7511_AUDIO */
 
 #endif /* __DRM_I2C_ADV7511_H__ */

drivers/gpu/drm/bridge/adv7511/adv7511_audio.c

···
+/*
+ * Analog Devices ADV7511 HDMI transmitter driver
+ *
+ * Copyright 2012 Analog Devices Inc.
+ * Copyright (c) 2016, Linaro Limited
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <sound/core.h>
+#include <sound/hdmi-codec.h>
+#include <sound/pcm.h>
+#include <sound/soc.h>
+
+#include "adv7511.h"
+
+static void adv7511_calc_cts_n(unsigned int f_tmds, unsigned int fs,
+			       unsigned int *cts, unsigned int *n)
+{
+	switch (fs) {
+	case 32000:
+		*n = 4096;
+		break;
+	case 44100:
+		*n = 6272;
+		break;
+	case 48000:
+		*n = 6144;
+		break;
+	}
+
+	*cts = ((f_tmds * *n) / (128 * fs)) * 1000;
+}
+
+static int adv7511_update_cts_n(struct adv7511 *adv7511)
+{
+	unsigned int cts = 0;
+	unsigned int n = 0;
+
+	adv7511_calc_cts_n(adv7511->f_tmds, adv7511->f_audio, &cts, &n);
+
+	regmap_write(adv7511->regmap, ADV7511_REG_N0, (n >> 16) & 0xf);
+	regmap_write(adv7511->regmap, ADV7511_REG_N1, (n >> 8) & 0xff);
+	regmap_write(adv7511->regmap, ADV7511_REG_N2, n & 0xff);
+
+	regmap_write(adv7511->regmap, ADV7511_REG_CTS_MANUAL0,
+		     (cts >> 16) & 0xf);
+	regmap_write(adv7511->regmap, ADV7511_REG_CTS_MANUAL1,
+		     (cts >> 8) & 0xff);
+	regmap_write(adv7511->regmap, ADV7511_REG_CTS_MANUAL2,
+		     cts & 0xff);
+
+	return 0;
+}
+
+int adv7511_hdmi_hw_params(struct device *dev, void *data,
+			   struct hdmi_codec_daifmt *fmt,
+			   struct hdmi_codec_params *hparms)
+{
+	struct adv7511 *adv7511 = dev_get_drvdata(dev);
+	unsigned int audio_source, i2s_format = 0;
+	unsigned int invert_clock;
+	unsigned int rate;
+	unsigned int len;
+
+	switch (hparms->sample_rate) {
+	case 32000:
+		rate = ADV7511_SAMPLE_FREQ_32000;
+		break;
+	case 44100:
+		rate = ADV7511_SAMPLE_FREQ_44100;
+		break;
+	case 48000:
+		rate = ADV7511_SAMPLE_FREQ_48000;
+		break;
+	case 88200:
+		rate = ADV7511_SAMPLE_FREQ_88200;
+		break;
+	case 96000:
+		rate = ADV7511_SAMPLE_FREQ_96000;
+		break;
+	case 176400:
+		rate = ADV7511_SAMPLE_FREQ_176400;
+		break;
+	case 192000:
+		rate = ADV7511_SAMPLE_FREQ_192000;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	switch (hparms->sample_width) {
+	case 16:
+		len = ADV7511_I2S_SAMPLE_LEN_16;
+		break;
+	case 18:
+		len = ADV7511_I2S_SAMPLE_LEN_18;
+		break;
+	case 20:
+		len = ADV7511_I2S_SAMPLE_LEN_20;
+		break;
+	case 24:
+		len = ADV7511_I2S_SAMPLE_LEN_24;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	switch (fmt->fmt) {
+	case HDMI_I2S:
+		audio_source = ADV7511_AUDIO_SOURCE_I2S;
+		i2s_format = ADV7511_I2S_FORMAT_I2S;
+		break;
+	case HDMI_RIGHT_J:
+		audio_source = ADV7511_AUDIO_SOURCE_I2S;
+		i2s_format = ADV7511_I2S_FORMAT_RIGHT_J;
+		break;
+	case HDMI_LEFT_J:
+		audio_source = ADV7511_AUDIO_SOURCE_I2S;
+		i2s_format = ADV7511_I2S_FORMAT_LEFT_J;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	invert_clock = fmt->bit_clk_inv;
+
+	regmap_update_bits(adv7511->regmap, ADV7511_REG_AUDIO_SOURCE, 0x70,
+			   audio_source << 4);
+	regmap_update_bits(adv7511->regmap, ADV7511_REG_AUDIO_CONFIG, BIT(6),
+			   invert_clock << 6);
+	regmap_update_bits(adv7511->regmap, ADV7511_REG_I2S_CONFIG, 0x03,
+			   i2s_format);
+
+	adv7511->audio_source = audio_source;
+
+	adv7511->f_audio = hparms->sample_rate;
+
+	adv7511_update_cts_n(adv7511);
+
+	regmap_update_bits(adv7511->regmap, ADV7511_REG_AUDIO_CFG3,
+			   ADV7511_AUDIO_CFG3_LEN_MASK, len);
+	regmap_update_bits(adv7511->regmap, ADV7511_REG_I2C_FREQ_ID_CFG,
+			   ADV7511_I2C_FREQ_ID_CFG_RATE_MASK, rate << 4);
+	regmap_write(adv7511->regmap, 0x73, 0x1);
+
+	return 0;
+}
+
+static int audio_startup(struct device *dev, void *data)
+{
+	struct adv7511 *adv7511 = dev_get_drvdata(dev);
+
+	regmap_update_bits(adv7511->regmap, ADV7511_REG_AUDIO_CONFIG,
+				BIT(7), 0);
+
+	/* hide Audio infoframe updates */
+	regmap_update_bits(adv7511->regmap, ADV7511_REG_INFOFRAME_UPDATE,
+				BIT(5), BIT(5));
+	/* enable N/CTS, enable Audio sample packets */
+	regmap_update_bits(adv7511->regmap, ADV7511_REG_PACKET_ENABLE1,
+				BIT(5), BIT(5));
+	/* enable N/CTS */
+	regmap_update_bits(adv7511->regmap, ADV7511_REG_PACKET_ENABLE1,
+				BIT(6), BIT(6));
+	/* not copyrighted */
+	regmap_update_bits(adv7511->regmap, ADV7511_REG_AUDIO_CFG1,
+				BIT(5), BIT(5));
+	/* enable audio infoframes */
+	regmap_update_bits(adv7511->regmap, ADV7511_REG_PACKET_ENABLE1,
+				BIT(3), BIT(3));
+	/* AV mute disable */
+	regmap_update_bits(adv7511->regmap, ADV7511_REG_GC(0),
+				BIT(7) | BIT(6), BIT(7));
+	/* use Audio infoframe updated info */
+	regmap_update_bits(adv7511->regmap, ADV7511_REG_GC(1),
+				BIT(5), 0);
+	return 0;
+}
+
+static void audio_shutdown(struct device *dev, void *data)
+{
+}
+
+static const struct hdmi_codec_ops adv7511_codec_ops = {
+	.hw_params	= adv7511_hdmi_hw_params,
+	.audio_shutdown = audio_shutdown,
+	.audio_startup	= audio_startup,
+};
+
+static struct hdmi_codec_pdata codec_data = {
+	.ops = &adv7511_codec_ops,
+	.max_i2s_channels = 2,
+	.i2s = 1,
+};
+
+int adv7511_audio_init(struct device *dev, struct adv7511 *adv7511)
+{
+	adv7511->audio_pdev = platform_device_register_data(dev,
+					HDMI_CODEC_DRV_NAME,
+					PLATFORM_DEVID_AUTO,
+					&codec_data,
+					sizeof(codec_data));
+	return PTR_ERR_OR_ZERO(adv7511->audio_pdev);
+}
+
+void adv7511_audio_exit(struct adv7511 *adv7511)
+{
+	if (adv7511->audio_pdev) {
+		platform_device_unregister(adv7511->audio_pdev);
+		adv7511->audio_pdev = NULL;
+	}
+}

drivers/gpu/drm/bridge/adv7511/adv7511_drv.c

···
 		goto err_unregister_cec;
 	}
 
+	adv7511_audio_init(dev, adv7511);
+
 	return 0;
 
 err_unregister_cec:
···
 	}
 
 	drm_bridge_remove(&adv7511->bridge);
+
+	adv7511_audio_exit(adv7511);
 
 	i2c_unregister_device(adv7511->i2c_edid);