drm: bridge: add DesignWare HDMI I2S audio support

Current dw-hdmi is supporting sound via AHB bus, but it has
I2S audio feature too. This patch adds I2S audio support to dw-hdmi.
This HDMI I2S is supported by using ALSA SoC common HDMI encoder
driver.

Tested-by: Jose Abreu <[e-mail]>
Acked-by: Russell King <[e-mail]>
Signed-off-by: Kuninori Morimoto <[e-mail]>
Signed-off-by: Archit Taneja <[e-mail]>
Link: http://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/bridge/Kconfig

···
 	  Designware HDMI block.  This is used in conjunction with
 	  the i.MX6 HDMI driver.
 
+config DRM_DW_HDMI_I2S_AUDIO
+	tristate "Synopsis Designware I2S Audio interface"
+	depends on DRM_DW_HDMI
+	select SND_SOC_HDMI_CODEC
+	help
+	  Support the I2S Audio interface which is part of the Synopsis
+	  Designware HDMI block.
+
 config DRM_NXP_PTN3460
 	tristate "NXP PTN3460 DP/LVDS bridge"
 	depends on OF

drivers/gpu/drm/bridge/Makefile

···
 obj-$(CONFIG_DRM_DUMB_VGA_DAC) += dumb-vga-dac.o
 obj-$(CONFIG_DRM_DW_HDMI) += dw-hdmi.o
 obj-$(CONFIG_DRM_DW_HDMI_AHB_AUDIO) += dw-hdmi-ahb-audio.o
+obj-$(CONFIG_DRM_DW_HDMI_I2S_AUDIO) += dw-hdmi-i2s-audio.o
 obj-$(CONFIG_DRM_NXP_PTN3460) += nxp-ptn3460.o
 obj-$(CONFIG_DRM_PARADE_PS8622) += parade-ps8622.o
 obj-$(CONFIG_DRM_SIL_SII8620) += sil-sii8620.o

drivers/gpu/drm/bridge/dw-hdmi-audio.h

···
 	u8 *eld;
 };
 
+struct dw_hdmi_i2s_audio_data {
+	struct dw_hdmi *hdmi;
+
+	void (*write)(struct dw_hdmi *hdmi, u8 val, int offset);
+	u8 (*read)(struct dw_hdmi *hdmi, int offset);
+};
+
 #endif

drivers/gpu/drm/bridge/dw-hdmi-i2s-audio.c

···
+/*
+ * dw-hdmi-i2s-audio.c
+ *
+ * Copyright (c) 2016 Kuninori Morimoto <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <drm/bridge/dw_hdmi.h>
+
+#include <sound/hdmi-codec.h>
+
+#include "dw-hdmi.h"
+#include "dw-hdmi-audio.h"
+
+#define DRIVER_NAME "dw-hdmi-i2s-audio"
+
+static inline void hdmi_write(struct dw_hdmi_i2s_audio_data *audio,
+			      u8 val, int offset)
+{
+	struct dw_hdmi *hdmi = audio->hdmi;
+
+	audio->write(hdmi, val, offset);
+}
+
+static inline u8 hdmi_read(struct dw_hdmi_i2s_audio_data *audio, int offset)
+{
+	struct dw_hdmi *hdmi = audio->hdmi;
+
+	return audio->read(hdmi, offset);
+}
+
+static int dw_hdmi_i2s_hw_params(struct device *dev, void *data,
+				 struct hdmi_codec_daifmt *fmt,
+				 struct hdmi_codec_params *hparms)
+{
+	struct dw_hdmi_i2s_audio_data *audio = data;
+	struct dw_hdmi *hdmi = audio->hdmi;
+	u8 conf0 = 0;
+	u8 conf1 = 0;
+	u8 inputclkfs = 0;
+
+	/* it cares I2S only */
+	if ((fmt->fmt != HDMI_I2S) ||
+	    (fmt->bit_clk_master | fmt->frame_clk_master)) {
+		dev_err(dev, "unsupported format/settings\n");
+		return -EINVAL;
+	}
+
+	inputclkfs	= HDMI_AUD_INPUTCLKFS_64FS;
+	conf0		= HDMI_AUD_CONF0_I2S_ALL_ENABLE;
+
+	switch (hparms->sample_width) {
+	case 16:
+		conf1 = HDMI_AUD_CONF1_WIDTH_16;
+		break;
+	case 24:
+	case 32:
+		conf1 = HDMI_AUD_CONF1_WIDTH_24;
+		break;
+	}
+
+	dw_hdmi_set_sample_rate(hdmi, hparms->sample_rate);
+
+	hdmi_write(audio, inputclkfs, HDMI_AUD_INPUTCLKFS);
+	hdmi_write(audio, conf0, HDMI_AUD_CONF0);
+	hdmi_write(audio, conf1, HDMI_AUD_CONF1);
+
+	dw_hdmi_audio_enable(hdmi);
+
+	return 0;
+}
+
+static void dw_hdmi_i2s_audio_shutdown(struct device *dev, void *data)
+{
+	struct dw_hdmi_i2s_audio_data *audio = data;
+	struct dw_hdmi *hdmi = audio->hdmi;
+
+	dw_hdmi_audio_disable(hdmi);
+
+	hdmi_write(audio, HDMI_AUD_CONF0_SW_RESET, HDMI_AUD_CONF0);
+}
+
+static struct hdmi_codec_ops dw_hdmi_i2s_ops = {
+	.hw_params	= dw_hdmi_i2s_hw_params,
+	.audio_shutdown	= dw_hdmi_i2s_audio_shutdown,
+};
+
+static int snd_dw_hdmi_probe(struct platform_device *pdev)
+{
+	struct dw_hdmi_i2s_audio_data *audio = pdev->dev.platform_data;
+	struct platform_device_info pdevinfo;
+	struct hdmi_codec_pdata pdata;
+	struct platform_device *platform;
+
+	pdata.ops		= &dw_hdmi_i2s_ops;
+	pdata.i2s		= 1;
+	pdata.max_i2s_channels	= 6;
+	pdata.data		= audio;
+
+	memset(&pdevinfo, 0, sizeof(pdevinfo));
+	pdevinfo.parent		= pdev->dev.parent;
+	pdevinfo.id		= PLATFORM_DEVID_AUTO;
+	pdevinfo.name		= HDMI_CODEC_DRV_NAME;
+	pdevinfo.data		= &pdata;
+	pdevinfo.size_data	= sizeof(pdata);
+	pdevinfo.dma_mask	= DMA_BIT_MASK(32);
+
+	platform = platform_device_register_full(&pdevinfo);
+	if (IS_ERR(platform))
+		return PTR_ERR(platform);
+
+	dev_set_drvdata(&pdev->dev, platform);
+
+	return 0;
+}
+
+static int snd_dw_hdmi_remove(struct platform_device *pdev)
+{
+	struct platform_device *platform = dev_get_drvdata(&pdev->dev);
+
+	platform_device_unregister(platform);
+
+	return 0;
+}
+
+static struct platform_driver snd_dw_hdmi_driver = {
+	.probe	= snd_dw_hdmi_probe,
+	.remove	= snd_dw_hdmi_remove,
+	.driver	= {
+		.name = DRIVER_NAME,
+		.owner = THIS_MODULE,
+	},
+};
+module_platform_driver(snd_dw_hdmi_driver);
+
+MODULE_AUTHOR("Kuninori Morimoto <[e-mail]>");
+MODULE_DESCRIPTION("Synopsis Designware HDMI I2S ALSA SoC interface");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" DRIVER_NAME);

drivers/gpu/drm/bridge/dw-hdmi.c

···
 	struct device_node *np = dev->of_node;
 	struct platform_device_info pdevinfo;
 	struct device_node *ddc_node;
-	struct dw_hdmi_audio_data audio;
 	struct dw_hdmi *hdmi;
 	int ret;
 	u32 val = 1;
+	u8 config0;
+	u8 config1;
 
 	hdmi = devm_kzalloc(dev, sizeof(*hdmi), GFP_KERNEL);
 	if (!hdmi)
···
 	pdevinfo.parent = dev;
 	pdevinfo.id = PLATFORM_DEVID_AUTO;
 
-	if (hdmi_readb(hdmi, HDMI_CONFIG1_ID) & HDMI_CONFIG1_AHB) {
+	config0 = hdmi_readb(hdmi, HDMI_CONFIG0_ID);
+	config1 = hdmi_readb(hdmi, HDMI_CONFIG1_ID);
+
+	if (config1 & HDMI_CONFIG1_AHB) {
+		struct dw_hdmi_audio_data audio;
+
 		audio.phys = iores->start;
 		audio.base = hdmi->regs;
 		audio.irq = irq;
···
 		audio.eld = hdmi->connector.eld;
 
 		pdevinfo.name = "dw-hdmi-ahb-audio";
+		pdevinfo.data = &audio;
+		pdevinfo.size_data = sizeof(audio);
+		pdevinfo.dma_mask = DMA_BIT_MASK(32);
+		hdmi->audio = platform_device_register_full(&pdevinfo);
+	} else if (config0 & HDMI_CONFIG0_I2S) {
+		struct dw_hdmi_i2s_audio_data audio;
+
+		audio.hdmi	= hdmi;
+		audio.write	= hdmi_writeb;
+		audio.read	= hdmi_readb;
+
+		pdevinfo.name = "dw-hdmi-i2s-audio";
 		pdevinfo.data = &audio;
 		pdevinfo.size_data = sizeof(audio);
 		pdevinfo.dma_mask = DMA_BIT_MASK(32);

drivers/gpu/drm/bridge/dw-hdmi.h

···
 #define HDMI_I2CM_FS_SCL_LCNT_0_ADDR            0x7E12
 
 enum {
+/* CONFIG0_ID field values */
+	HDMI_CONFIG0_I2S = 0x10,
+
 /* CONFIG1_ID field values */
 	HDMI_CONFIG1_AHB = 0x01,
 
···
 	HDMI_PHY_I2CM_CTLINT_ADDR_ARBITRATION_POL = 0x08,
 	HDMI_PHY_I2CM_CTLINT_ADDR_ARBITRATION_MASK = 0x04,
 
+/* AUD_CONF0 field values */
+	HDMI_AUD_CONF0_SW_RESET = 0x80,
+	HDMI_AUD_CONF0_I2S_ALL_ENABLE = 0x2F,
+
+/* AUD_CONF1 field values */
+	HDMI_AUD_CONF1_MODE_I2S = 0x00,
+	HDMI_AUD_CONF1_MODE_RIGHT_J = 0x02,
+	HDMI_AUD_CONF1_MODE_LEFT_J = 0x04,
+	HDMI_AUD_CONF1_WIDTH_16 = 0x10,
+	HDMI_AUD_CONF1_WIDTH_24 = 0x18,
+
 /* AUD_CTS3 field values */
 	HDMI_AUD_CTS3_N_SHIFT_OFFSET = 5,
 	HDMI_AUD_CTS3_N_SHIFT_MASK = 0xe0,
···
 	   from our part. Can't set it, will read as 0. */
 	HDMI_AUD_CTS3_CTS_MANUAL = 0x10,
 	HDMI_AUD_CTS3_AUDCTS19_16_MASK = 0x0f,
+
+/* HDMI_AUD_INPUTCLKFS field values */
+	HDMI_AUD_INPUTCLKFS_128FS = 0,
+	HDMI_AUD_INPUTCLKFS_256FS = 1,
+	HDMI_AUD_INPUTCLKFS_512FS = 2,
+	HDMI_AUD_INPUTCLKFS_64FS = 4,
 
 /* AHB_DMA_CONF0 field values */
 	HDMI_AHB_DMA_CONF0_SW_FIFO_RST_OFFSET = 7,