ASoC: cs42l42: Add SoundWire support

Merge series from Stefan Binding <sbinding@opensource.cirrus.com>:

The CS42L42 has a SoundWire interface for control and audio. This
chain of patches adds support for this.

Patches #1 .. #5 split out various changes to the existing code that
are needed for adding Soundwire. These are mostly around clocking and
supporting the separate probe and enumeration stages in SoundWire.

Patches #6 .. #8 actually adds the SoundWire handling.

drivers/soundwire/stream.c

@@ -469,7 +469,7 @@ static int sdw_prep_deprep_slave_ports(struct sdw_bus *bus,
 	}
 
 	/* Inform slave about the impending port prepare */
-	sdw_do_port_prep(s_rt, prep_ch, SDW_OPS_PORT_PRE_PREP);
+	sdw_do_port_prep(s_rt, prep_ch, prep ? SDW_OPS_PORT_PRE_PREP : SDW_OPS_PORT_PRE_DEPREP);
 
 	/* Prepare Slave port implementing CP_SM */
 	if (!dpn_prop->simple_ch_prep_sm) {
@@ -501,7 +501,7 @@ static int sdw_prep_deprep_slave_ports(struct sdw_bus *bus,
 	}
 
 	/* Inform slaves about ports prepared */
-	sdw_do_port_prep(s_rt, prep_ch, SDW_OPS_PORT_POST_PREP);
+	sdw_do_port_prep(s_rt, prep_ch, prep ? SDW_OPS_PORT_POST_PREP : SDW_OPS_PORT_POST_DEPREP);
 
 	/* Disable interrupt after Port de-prepare */
 	if (!prep && intr)

include/linux/soundwire/sdw.h

@@ -566,13 +566,15 @@ struct sdw_prepare_ch {
  * enum sdw_port_prep_ops: Prepare operations for Data Port
  *
  * @SDW_OPS_PORT_PRE_PREP: Pre prepare operation for the Port
- * @SDW_OPS_PORT_PREP: Prepare operation for the Port
+ * @SDW_OPS_PORT_PRE_DEPREP: Pre deprepare operation for the Port
  * @SDW_OPS_PORT_POST_PREP: Post prepare operation for the Port
+ * @SDW_OPS_PORT_POST_DEPREP: Post deprepare operation for the Port
  */
 enum sdw_port_prep_ops {
 	SDW_OPS_PORT_PRE_PREP = 0,
-	SDW_OPS_PORT_PREP = 1,
-	SDW_OPS_PORT_POST_PREP = 2,
+	SDW_OPS_PORT_PRE_DEPREP,
+	SDW_OPS_PORT_POST_PREP,
+	SDW_OPS_PORT_POST_DEPREP,
 };
 
 /**

include/sound/cs42l42.h

@@ -34,6 +34,7 @@
 #define CS42L42_PAGE_24		0x2400
 #define CS42L42_PAGE_25		0x2500
 #define CS42L42_PAGE_26		0x2600
+#define CS42L42_PAGE_27		0x2700
 #define CS42L42_PAGE_28		0x2800
 #define CS42L42_PAGE_29		0x2900
 #define CS42L42_PAGE_2A		0x2A00
@@ -720,6 +721,10 @@
 
 #define CS42L42_SRC_SDOUT_FS		(CS42L42_PAGE_26 + 0x09)
 
+/* Page 0x27 DMA */
+#define CS42L42_SOFT_RESET_REBOOT	(CS42L42_PAGE_27 + 0x01)
+#define CS42L42_SFT_RST_REBOOT_MASK	BIT(1)
+
 /* Page 0x28 S/PDIF Registers */
 #define CS42L42_SPDIF_CTL1		(CS42L42_PAGE_28 + 0x01)
 #define CS42L42_SPDIF_CTL2		(CS42L42_PAGE_28 + 0x02)

sound/soc/codecs/Kconfig

@@ -69,6 +69,7 @@ config SND_SOC_ALL_CODECS
 	imply SND_SOC_CS35L45_I2C
 	imply SND_SOC_CS35L45_SPI
 	imply SND_SOC_CS42L42
+	imply SND_SOC_CS42L42_SDW
 	imply SND_SOC_CS42L51_I2C
 	imply SND_SOC_CS42L52
 	imply SND_SOC_CS42L56
@@ -722,6 +723,13 @@ config SND_SOC_CS42L42
 	select REGMAP_I2C
 	select SND_SOC_CS42L42_CORE
 
+config SND_SOC_CS42L42_SDW
+	tristate "Cirrus Logic CS42L42 CODEC on Soundwire"
+	depends on SOUNDWIRE
+	select SND_SOC_CS42L42_CORE
+	help
+	  Enable support for Cirrus Logic CS42L42 codec with Soundwire control
+
 config SND_SOC_CS42L51
 	tristate
 

sound/soc/codecs/Makefile

@@ -69,6 +69,7 @@ snd-soc-cs35l45-spi-objs := cs35l45-spi.o
 snd-soc-cs35l45-i2c-objs := cs35l45-i2c.o
 snd-soc-cs42l42-objs := cs42l42.o
 snd-soc-cs42l42-i2c-objs := cs42l42-i2c.o
+snd-soc-cs42l42-sdw-objs := cs42l42-sdw.o
 snd-soc-cs42l51-objs := cs42l51.o
 snd-soc-cs42l51-i2c-objs := cs42l51-i2c.o
 snd-soc-cs42l52-objs := cs42l52.o
@@ -434,6 +435,7 @@ obj-$(CONFIG_SND_SOC_CS35L45_SPI)	+= snd-soc-cs35l45-spi.o
 obj-$(CONFIG_SND_SOC_CS35L45_I2C)	+= snd-soc-cs35l45-i2c.o
 obj-$(CONFIG_SND_SOC_CS42L42_CORE)	+= snd-soc-cs42l42.o
 obj-$(CONFIG_SND_SOC_CS42L42)	+= snd-soc-cs42l42-i2c.o
+obj-$(CONFIG_SND_SOC_CS42L42_SDW)	+= snd-soc-cs42l42-sdw.o
 obj-$(CONFIG_SND_SOC_CS42L51)	+= snd-soc-cs42l51.o
 obj-$(CONFIG_SND_SOC_CS42L51_I2C)	+= snd-soc-cs42l51-i2c.o
 obj-$(CONFIG_SND_SOC_CS42L52)	+= snd-soc-cs42l52.o

sound/soc/codecs/cs42l42-sdw.c

+// SPDX-License-Identifier: GPL-2.0-only
+// cs42l42-sdw.c -- CS42L42 ALSA SoC audio driver SoundWire driver
+//
+// Copyright (C) 2022 Cirrus Logic, Inc. and
+//                    Cirrus Logic International Semiconductor Ltd.
+
+#include <linux/acpi.h>
+#include <linux/device.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/of_irq.h>
+#include <linux/pm_runtime.h>
+#include <linux/soundwire/sdw.h>
+#include <linux/soundwire/sdw_registers.h>
+#include <linux/soundwire/sdw_type.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/sdw.h>
+#include <sound/soc.h>
+
+#include "cs42l42.h"
+
+#define CS42L42_SDW_CAPTURE_PORT	1
+#define CS42L42_SDW_PLAYBACK_PORT	2
+
+/* Register addresses are offset when sent over SoundWire */
+#define CS42L42_SDW_ADDR_OFFSET		0x8000
+
+#define CS42L42_SDW_MEM_ACCESS_STATUS	0xd0
+#define CS42L42_SDW_MEM_READ_DATA	0xd8
+
+#define CS42L42_SDW_LAST_LATE		BIT(3)
+#define CS42L42_SDW_CMD_IN_PROGRESS	BIT(2)
+#define CS42L42_SDW_RDATA_RDY		BIT(0)
+
+#define CS42L42_DELAYED_READ_POLL_US	1
+#define CS42L42_DELAYED_READ_TIMEOUT_US	100
+
+static const struct snd_soc_dapm_route cs42l42_sdw_audio_map[] = {
+	/* Playback Path */
+	{ "HP", NULL, "MIXER" },
+	{ "MIXER", NULL, "DACSRC" },
+	{ "DACSRC", NULL, "Playback" },
+
+	/* Capture Path */
+	{ "ADCSRC", NULL, "HS" },
+	{ "Capture", NULL, "ADCSRC" },
+};
+
+static int cs42l42_sdw_dai_startup(struct snd_pcm_substream *substream,
+				   struct snd_soc_dai *dai)
+{
+	struct cs42l42_private *cs42l42 = snd_soc_component_get_drvdata(dai->component);
+
+	if (!cs42l42->init_done)
+		return -ENODEV;
+
+	return 0;
+}
+
+static int cs42l42_sdw_dai_hw_params(struct snd_pcm_substream *substream,
+				     struct snd_pcm_hw_params *params,
+				     struct snd_soc_dai *dai)
+{
+	struct cs42l42_private *cs42l42 = snd_soc_component_get_drvdata(dai->component);
+	struct sdw_stream_runtime *sdw_stream = snd_soc_dai_get_dma_data(dai, substream);
+	struct sdw_stream_config stream_config = {0};
+	struct sdw_port_config port_config = {0};
+	int ret;
+
+	if (!sdw_stream)
+		return -EINVAL;
+
+	/* Needed for PLL configuration when we are notified of new bus config */
+	cs42l42->sample_rate = params_rate(params);
+
+	snd_sdw_params_to_config(substream, params, &stream_config, &port_config);
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+		port_config.num = CS42L42_SDW_PLAYBACK_PORT;
+	else
+		port_config.num = CS42L42_SDW_CAPTURE_PORT;
+
+	ret = sdw_stream_add_slave(cs42l42->sdw_peripheral, &stream_config, &port_config, 1,
+				   sdw_stream);
+	if (ret) {
+		dev_err(dai->dev, "Failed to add sdw stream: %d\n", ret);
+		return ret;
+	}
+
+	cs42l42_src_config(dai->component, params_rate(params));
+
+	return 0;
+}
+
+static int cs42l42_sdw_dai_prepare(struct snd_pcm_substream *substream,
+				   struct snd_soc_dai *dai)
+{
+	struct cs42l42_private *cs42l42 = snd_soc_component_get_drvdata(dai->component);
+
+	dev_dbg(dai->dev, "dai_prepare: sclk=%u rate=%u\n", cs42l42->sclk, cs42l42->sample_rate);
+
+	if (!cs42l42->sclk || !cs42l42->sample_rate)
+		return -EINVAL;
+
+	/*
+	 * At this point we know the sample rate from hw_params, and the SWIRE_CLK from bus_config()
+	 * callback. This could only fail if the ACPI or machine driver are misconfigured to allow
+	 * an unsupported SWIRE_CLK and sample_rate combination.
+	 */
+
+	return cs42l42_pll_config(dai->component, cs42l42->sclk, cs42l42->sample_rate);
+}
+
+static int cs42l42_sdw_dai_hw_free(struct snd_pcm_substream *substream,
+				   struct snd_soc_dai *dai)
+{
+	struct cs42l42_private *cs42l42 = snd_soc_component_get_drvdata(dai->component);
+	struct sdw_stream_runtime *sdw_stream = snd_soc_dai_get_dma_data(dai, substream);
+
+	sdw_stream_remove_slave(cs42l42->sdw_peripheral, sdw_stream);
+	cs42l42->sample_rate = 0;
+
+	return 0;
+}
+
+static int cs42l42_sdw_port_prep(struct sdw_slave *slave,
+				 struct sdw_prepare_ch *prepare_ch,
+				 enum sdw_port_prep_ops state)
+{
+	struct cs42l42_private *cs42l42 = dev_get_drvdata(&slave->dev);
+	unsigned int pdn_mask;
+
+	if (prepare_ch->num == CS42L42_SDW_PLAYBACK_PORT)
+		pdn_mask = CS42L42_HP_PDN_MASK;
+	else
+		pdn_mask = CS42L42_ADC_PDN_MASK;
+
+	if (state == SDW_OPS_PORT_PRE_PREP) {
+		dev_dbg(cs42l42->dev, "Prep Port pdn_mask:%x\n", pdn_mask);
+		regmap_clear_bits(cs42l42->regmap, CS42L42_PWR_CTL1, pdn_mask);
+		usleep_range(CS42L42_HP_ADC_EN_TIME_US, CS42L42_HP_ADC_EN_TIME_US + 1000);
+	} else if (state == SDW_OPS_PORT_POST_DEPREP) {
+		dev_dbg(cs42l42->dev, "Deprep Port pdn_mask:%x\n", pdn_mask);
+		regmap_set_bits(cs42l42->regmap, CS42L42_PWR_CTL1, pdn_mask);
+	}
+
+	return 0;
+}
+
+static int cs42l42_sdw_dai_set_sdw_stream(struct snd_soc_dai *dai, void *sdw_stream,
+					  int direction)
+{
+	if (!sdw_stream)
+		return 0;
+
+	if (direction == SNDRV_PCM_STREAM_PLAYBACK)
+		dai->playback_dma_data = sdw_stream;
+	else
+		dai->capture_dma_data = sdw_stream;
+
+	return 0;
+}
+
+static void cs42l42_sdw_dai_shutdown(struct snd_pcm_substream *substream,
+				     struct snd_soc_dai *dai)
+{
+	snd_soc_dai_set_dma_data(dai, substream, NULL);
+}
+
+static const struct snd_soc_dai_ops cs42l42_sdw_dai_ops = {
+	.startup	= cs42l42_sdw_dai_startup,
+	.shutdown	= cs42l42_sdw_dai_shutdown,
+	.hw_params	= cs42l42_sdw_dai_hw_params,
+	.prepare	= cs42l42_sdw_dai_prepare,
+	.hw_free	= cs42l42_sdw_dai_hw_free,
+	.mute_stream	= cs42l42_mute_stream,
+	.set_stream	= cs42l42_sdw_dai_set_sdw_stream,
+};
+
+static struct snd_soc_dai_driver cs42l42_sdw_dai = {
+	.name = "cs42l42-sdw",
+	.playback = {
+		.stream_name = "Playback",
+		.channels_min = 1,
+		.channels_max = 2,
+		/* Restrict which rates and formats are supported */
+		.rates = SNDRV_PCM_RATE_8000_96000,
+		.formats = SNDRV_PCM_FMTBIT_S16_LE |
+			   SNDRV_PCM_FMTBIT_S24_LE |
+			   SNDRV_PCM_FMTBIT_S32_LE,
+	},
+	.capture = {
+		.stream_name = "Capture",
+		.channels_min = 1,
+		.channels_max = 1,
+		/* Restrict which rates and formats are supported */
+		.rates = SNDRV_PCM_RATE_8000_96000,
+		.formats = SNDRV_PCM_FMTBIT_S16_LE |
+			   SNDRV_PCM_FMTBIT_S24_LE |
+			   SNDRV_PCM_FMTBIT_S32_LE,
+	},
+	.symmetric_rate = 1,
+	.ops = &cs42l42_sdw_dai_ops,
+};
+
+static int cs42l42_sdw_poll_status(struct sdw_slave *peripheral, u8 mask, u8 match)
+{
+	int ret, sdwret;
+
+	ret = read_poll_timeout(sdw_read_no_pm, sdwret,
+				(sdwret < 0) || ((sdwret & mask) == match),
+				CS42L42_DELAYED_READ_POLL_US, CS42L42_DELAYED_READ_TIMEOUT_US,
+				false, peripheral, CS42L42_SDW_MEM_ACCESS_STATUS);
+	if (ret == 0)
+		ret = sdwret;
+
+	if (ret < 0)
+		dev_err(&peripheral->dev, "MEM_ACCESS_STATUS & %#x for %#x fail: %d\n",
+			mask, match, ret);
+
+	return ret;
+}
+
+static int cs42l42_sdw_read(void *context, unsigned int reg, unsigned int *val)
+{
+	struct sdw_slave *peripheral = context;
+	u8 data;
+	int ret;
+
+	reg += CS42L42_SDW_ADDR_OFFSET;
+
+	ret = cs42l42_sdw_poll_status(peripheral, CS42L42_SDW_CMD_IN_PROGRESS, 0);
+	if (ret < 0)
+		return ret;
+
+	ret = sdw_read_no_pm(peripheral, reg);
+	if (ret < 0) {
+		dev_err(&peripheral->dev, "Failed to issue read @0x%x: %d\n", reg, ret);
+		return ret;
+	}
+
+	data = (u8)ret;	/* possible non-delayed read value */
+	ret = sdw_read_no_pm(peripheral, CS42L42_SDW_MEM_ACCESS_STATUS);
+	if (ret < 0) {
+		dev_err(&peripheral->dev, "Failed to read MEM_ACCESS_STATUS: %d\n", ret);
+		return ret;
+	}
+
+	/* If read was not delayed we already have the result */
+	if ((ret & CS42L42_SDW_LAST_LATE) == 0) {
+		*val = data;
+		return 0;
+	}
+
+	/* Poll for delayed read completion */
+	if ((ret & CS42L42_SDW_RDATA_RDY) == 0) {
+		ret = cs42l42_sdw_poll_status(peripheral,
+					      CS42L42_SDW_RDATA_RDY, CS42L42_SDW_RDATA_RDY);
+		if (ret < 0)
+			return ret;
+	}
+
+	ret = sdw_read_no_pm(peripheral, CS42L42_SDW_MEM_READ_DATA);
+	if (ret < 0) {
+		dev_err(&peripheral->dev, "Failed to read READ_DATA: %d\n", ret);
+		return ret;
+	}
+
+	*val = (u8)ret;
+
+	return 0;
+}
+
+static int cs42l42_sdw_write(void *context, unsigned int reg, unsigned int val)
+{
+	struct sdw_slave *peripheral = context;
+	int ret;
+
+	ret = cs42l42_sdw_poll_status(peripheral, CS42L42_SDW_CMD_IN_PROGRESS, 0);
+	if (ret < 0)
+		return ret;
+
+	return sdw_write_no_pm(peripheral, reg + CS42L42_SDW_ADDR_OFFSET, (u8)val);
+}
+
+/* Initialise cs42l42 using SoundWire - this is only called once, during initialisation */
+static void cs42l42_sdw_init(struct sdw_slave *peripheral)
+{
+	struct cs42l42_private *cs42l42 = dev_get_drvdata(&peripheral->dev);
+	int ret;
+
+	regcache_cache_only(cs42l42->regmap, false);
+
+	ret = cs42l42_init(cs42l42);
+	if (ret < 0) {
+		regcache_cache_only(cs42l42->regmap, true);
+		goto err;
+	}
+
+	/* Write out any cached changes that happened between probe and attach */
+	ret = regcache_sync(cs42l42->regmap);
+	if (ret < 0)
+		dev_warn(cs42l42->dev, "Failed to sync cache: %d\n", ret);
+
+	/* Disable internal logic that makes clock-stop conditional */
+	regmap_clear_bits(cs42l42->regmap, CS42L42_PWR_CTL3, CS42L42_SW_CLK_STP_STAT_SEL_MASK);
+
+err:
+	/* This cancels the pm_runtime_get_noresume() call from cs42l42_sdw_probe(). */
+	pm_runtime_put_autosuspend(cs42l42->dev);
+}
+
+static int cs42l42_sdw_read_prop(struct sdw_slave *peripheral)
+{
+	struct cs42l42_private *cs42l42 = dev_get_drvdata(&peripheral->dev);
+	struct sdw_slave_prop *prop = &peripheral->prop;
+	struct sdw_dpn_prop *ports;
+
+	ports = devm_kcalloc(cs42l42->dev, 2, sizeof(*ports), GFP_KERNEL);
+	if (!ports)
+		return -ENOMEM;
+
+	prop->source_ports = BIT(CS42L42_SDW_CAPTURE_PORT);
+	prop->sink_ports = BIT(CS42L42_SDW_PLAYBACK_PORT);
+	prop->quirks = SDW_SLAVE_QUIRKS_INVALID_INITIAL_PARITY;
+	prop->scp_int1_mask = SDW_SCP_INT1_BUS_CLASH | SDW_SCP_INT1_PARITY;
+
+	/* DP1 - capture */
+	ports[0].num = CS42L42_SDW_CAPTURE_PORT,
+	ports[0].type = SDW_DPN_FULL,
+	ports[0].ch_prep_timeout = 10,
+	prop->src_dpn_prop = &ports[0];
+
+	/* DP2 - playback */
+	ports[1].num = CS42L42_SDW_PLAYBACK_PORT,
+	ports[1].type = SDW_DPN_FULL,
+	ports[1].ch_prep_timeout = 10,
+	prop->sink_dpn_prop = &ports[1];
+
+	return 0;
+}
+
+static int cs42l42_sdw_update_status(struct sdw_slave *peripheral,
+				     enum sdw_slave_status status)
+{
+	struct cs42l42_private *cs42l42 = dev_get_drvdata(&peripheral->dev);
+
+	switch (status) {
+	case SDW_SLAVE_ATTACHED:
+		dev_dbg(cs42l42->dev, "ATTACHED\n");
+		/*
+		 * Initialise codec, this only needs to be done once.
+		 * When resuming from suspend, resume callback will handle re-init of codec,
+		 * using regcache_sync().
+		 */
+		if (!cs42l42->init_done)
+			cs42l42_sdw_init(peripheral);
+		break;
+	case SDW_SLAVE_UNATTACHED:
+		dev_dbg(cs42l42->dev, "UNATTACHED\n");
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+static int cs42l42_sdw_bus_config(struct sdw_slave *peripheral,
+				  struct sdw_bus_params *params)
+{
+	struct cs42l42_private *cs42l42 = dev_get_drvdata(&peripheral->dev);
+	unsigned int new_sclk = params->curr_dr_freq / 2;
+
+	/* The cs42l42 cannot support a glitchless SWIRE_CLK change. */
+	if ((new_sclk != cs42l42->sclk) && cs42l42->stream_use) {
+		dev_warn(cs42l42->dev, "Rejected SCLK change while audio active\n");
+		return -EBUSY;
+	}
+
+	cs42l42->sclk = new_sclk;
+
+	dev_dbg(cs42l42->dev, "bus_config: sclk=%u c=%u r=%u\n",
+		cs42l42->sclk, params->col, params->row);
+
+	return 0;
+}
+
+static const struct sdw_slave_ops cs42l42_sdw_ops = {
+/* No interrupt callback because only hardware INT is supported for Jack Detect in the CS42L42 */
+	.read_prop = cs42l42_sdw_read_prop,
+	.update_status = cs42l42_sdw_update_status,
+	.bus_config = cs42l42_sdw_bus_config,
+	.port_prep = cs42l42_sdw_port_prep,
+};
+
+static int __maybe_unused cs42l42_sdw_runtime_suspend(struct device *dev)
+{
+	struct cs42l42_private *cs42l42 = dev_get_drvdata(dev);
+
+	dev_dbg(dev, "Runtime suspend\n");
+
+	if (!cs42l42->init_done)
+		return 0;
+
+	/* The host controller could suspend, which would mean no register access */
+	regcache_cache_only(cs42l42->regmap, true);
+
+	return 0;
+}
+
+static const struct reg_sequence __maybe_unused cs42l42_soft_reboot_seq[] = {
+	REG_SEQ0(CS42L42_SOFT_RESET_REBOOT, 0x1e),
+};
+
+static int __maybe_unused cs42l42_sdw_handle_unattach(struct cs42l42_private *cs42l42)
+{
+	struct sdw_slave *peripheral = cs42l42->sdw_peripheral;
+
+	if (!peripheral->unattach_request)
+		return 0;
+
+	/* Cannot access registers until master re-attaches. */
+	dev_dbg(&peripheral->dev, "Wait for initialization_complete\n");
+	if (!wait_for_completion_timeout(&peripheral->initialization_complete,
+					 msecs_to_jiffies(5000))) {
+		dev_err(&peripheral->dev, "initialization_complete timed out\n");
+		return -ETIMEDOUT;
+	}
+
+	peripheral->unattach_request = 0;
+
+	/*
+	 * After a bus reset there must be a reconfiguration reset to
+	 * reinitialize the internal state of CS42L42.
+	 */
+	regmap_multi_reg_write_bypassed(cs42l42->regmap,
+					cs42l42_soft_reboot_seq,
+					ARRAY_SIZE(cs42l42_soft_reboot_seq));
+	usleep_range(CS42L42_BOOT_TIME_US, CS42L42_BOOT_TIME_US * 2);
+	regcache_mark_dirty(cs42l42->regmap);
+
+	return 0;
+}
+
+static int __maybe_unused cs42l42_sdw_runtime_resume(struct device *dev)
+{
+	static const unsigned int ts_dbnce_ms[] = { 0, 125, 250, 500, 750, 1000, 1250, 1500};
+	struct cs42l42_private *cs42l42 = dev_get_drvdata(dev);
+	unsigned int dbnce;
+	int ret;
+
+	dev_dbg(dev, "Runtime resume\n");
+
+	if (!cs42l42->init_done)
+		return 0;
+
+	ret = cs42l42_sdw_handle_unattach(cs42l42);
+	if (ret < 0) {
+		return ret;
+	} else if (ret > 0) {
+		dbnce = max(cs42l42->ts_dbnc_rise, cs42l42->ts_dbnc_fall);
+
+		if (dbnce > 0)
+			msleep(ts_dbnce_ms[dbnce]);
+	}
+
+	regcache_cache_only(cs42l42->regmap, false);
+
+	/* Sync LATCH_TO_VP first so the VP domain registers sync correctly */
+	regcache_sync_region(cs42l42->regmap, CS42L42_MIC_DET_CTL1, CS42L42_MIC_DET_CTL1);
+	regcache_sync(cs42l42->regmap);
+
+	return 0;
+}
+
+static int __maybe_unused cs42l42_sdw_resume(struct device *dev)
+{
+	struct cs42l42_private *cs42l42 = dev_get_drvdata(dev);
+	int ret;
+
+	dev_dbg(dev, "System resume\n");
+
+	/* Power-up so it can re-enumerate */
+	ret = cs42l42_resume(dev);
+	if (ret)
+		return ret;
+
+	/* Wait for re-attach */
+	ret = cs42l42_sdw_handle_unattach(cs42l42);
+	if (ret < 0)
+		return ret;
+
+	cs42l42_resume_restore(dev);
+
+	return 0;
+}
+
+static int cs42l42_sdw_probe(struct sdw_slave *peripheral, const struct sdw_device_id *id)
+{
+	struct snd_soc_component_driver *component_drv;
+	struct device *dev = &peripheral->dev;
+	struct cs42l42_private *cs42l42;
+	struct regmap_config *regmap_conf;
+	struct regmap *regmap;
+	int irq, ret;
+
+	cs42l42 = devm_kzalloc(dev, sizeof(*cs42l42), GFP_KERNEL);
+	if (!cs42l42)
+		return -ENOMEM;
+
+	if (has_acpi_companion(dev))
+		irq = acpi_dev_gpio_irq_get(ACPI_COMPANION(dev), 0);
+	else
+		irq = of_irq_get(dev->of_node, 0);
+
+	if (irq == -ENOENT)
+		irq = 0;
+	else if (irq < 0)
+		return dev_err_probe(dev, irq, "Failed to get IRQ\n");
+
+	regmap_conf = devm_kmemdup(dev, &cs42l42_regmap, sizeof(cs42l42_regmap), GFP_KERNEL);
+	if (!regmap_conf)
+		return -ENOMEM;
+	regmap_conf->reg_bits = 16;
+	regmap_conf->num_ranges = 0;
+	regmap_conf->reg_read = cs42l42_sdw_read;
+	regmap_conf->reg_write = cs42l42_sdw_write;
+
+	regmap = devm_regmap_init(dev, NULL, peripheral, regmap_conf);
+	if (IS_ERR(regmap))
+		return dev_err_probe(dev, PTR_ERR(regmap), "Failed to allocate register map\n");
+
+	/* Start in cache-only until device is enumerated */
+	regcache_cache_only(regmap, true);
+
+	component_drv = devm_kmemdup(dev,
+				     &cs42l42_soc_component,
+				     sizeof(cs42l42_soc_component),
+				     GFP_KERNEL);
+	if (!component_drv)
+		return -ENOMEM;
+
+	component_drv->dapm_routes = cs42l42_sdw_audio_map;
+	component_drv->num_dapm_routes = ARRAY_SIZE(cs42l42_sdw_audio_map);
+
+	cs42l42->dev = dev;
+	cs42l42->regmap = regmap;
+	cs42l42->sdw_peripheral = peripheral;
+	cs42l42->irq = irq;
+	cs42l42->devid = CS42L42_CHIP_ID;
+
+	/*
+	 * pm_runtime is needed to control bus manager suspend, and to
+	 * recover from an unattach_request when the manager suspends.
+	 */
+	pm_runtime_set_autosuspend_delay(cs42l42->dev, 3000);
+	pm_runtime_use_autosuspend(cs42l42->dev);
+	pm_runtime_mark_last_busy(cs42l42->dev);
+	pm_runtime_set_active(cs42l42->dev);
+	pm_runtime_get_noresume(cs42l42->dev);
+	pm_runtime_enable(cs42l42->dev);
+
+	ret = cs42l42_common_probe(cs42l42, component_drv, &cs42l42_sdw_dai);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static int cs42l42_sdw_remove(struct sdw_slave *peripheral)
+{
+	struct cs42l42_private *cs42l42 = dev_get_drvdata(&peripheral->dev);
+
+	cs42l42_common_remove(cs42l42);
+	pm_runtime_disable(cs42l42->dev);
+
+	return 0;
+}
+
+static const struct dev_pm_ops cs42l42_sdw_pm = {
+	SET_SYSTEM_SLEEP_PM_OPS(cs42l42_suspend, cs42l42_sdw_resume)
+	SET_RUNTIME_PM_OPS(cs42l42_sdw_runtime_suspend, cs42l42_sdw_runtime_resume, NULL)
+};
+
+static const struct sdw_device_id cs42l42_sdw_id[] = {
+	SDW_SLAVE_ENTRY(0x01FA, 0x4242, 0),
+	{},
+};
+MODULE_DEVICE_TABLE(sdw, cs42l42_sdw_id);
+
+static struct sdw_driver cs42l42_sdw_driver = {
+	.driver = {
+		.name = "cs42l42-sdw",
+		.pm = &cs42l42_sdw_pm,
+	},
+	.probe = cs42l42_sdw_probe,
+	.remove = cs42l42_sdw_remove,
+	.ops = &cs42l42_sdw_ops,
+	.id_table = cs42l42_sdw_id,
+};
+
+module_sdw_driver(cs42l42_sdw_driver);
+
+MODULE_DESCRIPTION("ASoC CS42L42 SoundWire driver");
+MODULE_AUTHOR("Richard Fitzgerald <rf@opensource.cirrus.com>");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(SND_SOC_CS42L42_CORE);

sound/soc/codecs/cs42l42.c

@@ -20,6 +20,7 @@
 #include <linux/slab.h>
 #include <linux/acpi.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/property.h>
 #include <linux/regulator/consumer.h>
 #include <linux/gpio/consumer.h>
@@ -293,6 +294,7 @@ bool cs42l42_readable_register(struct device *dev, unsigned int reg)
 	case CS42L42_SPDIF_SW_CTL1:
 	case CS42L42_SRC_SDIN_FS:
 	case CS42L42_SRC_SDOUT_FS:
+	case CS42L42_SOFT_RESET_REBOOT:
 	case CS42L42_SPDIF_CTL1:
 	case CS42L42_SPDIF_CTL2:
 	case CS42L42_SPDIF_CTL3:
@@ -358,6 +360,7 @@ bool cs42l42_volatile_register(struct device *dev, unsigned int reg)
 	case CS42L42_LOAD_DET_DONE:
 	case CS42L42_DET_STATUS1:
 	case CS42L42_DET_STATUS2:
+	case CS42L42_SOFT_RESET_REBOOT:
 		return true;
 	default:
 		return false;
@@ -523,6 +526,10 @@ static const struct snd_soc_dapm_widget cs42l42_dapm_widgets[] = {
 
 	/* Playback/Capture Requirements */
 	SND_SOC_DAPM_SUPPLY("SCLK", CS42L42_ASP_CLK_CFG, CS42L42_ASP_SCLK_EN_SHIFT, 0, NULL, 0),
+
+	/* Soundwire SRC power control */
+	SND_SOC_DAPM_PGA("DACSRC", CS42L42_PWR_CTL2, CS42L42_DAC_SRC_PDNB_SHIFT, 0, NULL, 0),
+	SND_SOC_DAPM_PGA("ADCSRC", CS42L42_PWR_CTL2, CS42L42_ADC_SRC_PDNB_SHIFT, 0, NULL, 0),
 };
 
 static const struct snd_soc_dapm_route cs42l42_audio_map[] = {
@@ -590,7 +597,6 @@ const struct snd_soc_component_driver cs42l42_soc_component = {
 	.num_dapm_routes	= ARRAY_SIZE(cs42l42_audio_map),
 	.controls		= cs42l42_snd_controls,
 	.num_controls		= ARRAY_SIZE(cs42l42_snd_controls),
-	.idle_bias_on		= 1,
 	.endianness		= 1,
 };
 EXPORT_SYMBOL_NS_GPL(cs42l42_soc_component, SND_SOC_CS42L42_CORE);
@@ -651,11 +657,11 @@ static const struct cs42l42_pll_params pll_ratio_table[] = {
 	{ 24576000, 1, 0x03, 0x40, 0x000000, 0x03, 0x10, 12288000, 128, 1}
 };
 
-static int cs42l42_pll_config(struct snd_soc_component *component, unsigned int clk)
+int cs42l42_pll_config(struct snd_soc_component *component, unsigned int clk,
+		       unsigned int sample_rate)
 {
 	struct cs42l42_private *cs42l42 = snd_soc_component_get_drvdata(component);
 	int i;
-	u32 fsync;
 
 	/* Don't reconfigure if there is an audio stream running */
 	if (cs42l42->stream_use) {
@@ -666,6 +672,10 @@ static int cs42l42_pll_config(struct snd_soc_component *component, unsigned int
 	}
 
 	for (i = 0; i < ARRAY_SIZE(pll_ratio_table); i++) {
+		/* MCLKint must be a multiple of the sample rate */
+		if (pll_ratio_table[i].mclk_int % sample_rate)
+			continue;
+
 		if (pll_ratio_table[i].sclk == clk) {
 			cs42l42->pll_config = i;
 
@@ -677,40 +687,6 @@ static int cs42l42_pll_config(struct snd_soc_component *component, unsigned int
 					(pll_ratio_table[i].mclk_int !=
 					24000000)) <<
 					CS42L42_INTERNAL_FS_SHIFT);
-
-			/* Set up the LRCLK */
-			fsync = clk / cs42l42->srate;
-			if (((fsync * cs42l42->srate) != clk)
-				|| ((fsync % 2) != 0)) {
-				dev_err(component->dev,
-					"Unsupported sclk %d/sample rate %d\n",
-					clk,
-					cs42l42->srate);
-				return -EINVAL;
-			}
-			/* Set the LRCLK period */
-			snd_soc_component_update_bits(component,
-					CS42L42_FSYNC_P_LOWER,
-					CS42L42_FSYNC_PERIOD_MASK,
-					CS42L42_FRAC0_VAL(fsync - 1) <<
-					CS42L42_FSYNC_PERIOD_SHIFT);
-			snd_soc_component_update_bits(component,
-					CS42L42_FSYNC_P_UPPER,
-					CS42L42_FSYNC_PERIOD_MASK,
-					CS42L42_FRAC1_VAL(fsync - 1) <<
-					CS42L42_FSYNC_PERIOD_SHIFT);
-			/* Set the LRCLK to 50% duty cycle */
-			fsync = fsync / 2;
-			snd_soc_component_update_bits(component,
-					CS42L42_FSYNC_PW_LOWER,
-					CS42L42_FSYNC_PULSE_WIDTH_MASK,
-					CS42L42_FRAC0_VAL(fsync - 1) <<
-					CS42L42_FSYNC_PULSE_WIDTH_SHIFT);
-			snd_soc_component_update_bits(component,
-					CS42L42_FSYNC_PW_UPPER,
-					CS42L42_FSYNC_PULSE_WIDTH_MASK,
-					CS42L42_FRAC1_VAL(fsync - 1) <<
-					CS42L42_FSYNC_PULSE_WIDTH_SHIFT);
 			if (pll_ratio_table[i].mclk_src_sel == 0) {
 				/* Pass the clock straight through */
 				snd_soc_component_update_bits(component,
@@ -768,8 +744,9 @@ static int cs42l42_pll_config(struct snd_soc_component *component, unsigned int
 
 	return -EINVAL;
 }
+EXPORT_SYMBOL_NS_GPL(cs42l42_pll_config, SND_SOC_CS42L42_CORE);
 
-static void cs42l42_src_config(struct snd_soc_component *component, unsigned int sample_rate)
+void cs42l42_src_config(struct snd_soc_component *component, unsigned int sample_rate)
 {
 	struct cs42l42_private *cs42l42 = snd_soc_component_get_drvdata(component);
 	unsigned int fs;
@@ -801,6 +778,47 @@ static void cs42l42_src_config(struct snd_soc_component *component, unsigned int
 				      CS42L42_CLK_OASRC_SEL_MASK,
 				      fs << CS42L42_CLK_OASRC_SEL_SHIFT);
 }
+EXPORT_SYMBOL_NS_GPL(cs42l42_src_config, SND_SOC_CS42L42_CORE);
+
+static int cs42l42_asp_config(struct snd_soc_component *component,
+			      unsigned int sclk, unsigned int sample_rate)
+{
+	u32 fsync = sclk / sample_rate;
+
+	/* Set up the LRCLK */
+	if (((fsync * sample_rate) != sclk) || ((fsync % 2) != 0)) {
+		dev_err(component->dev,
+			"Unsupported sclk %d/sample rate %d\n",
+			sclk,
+			sample_rate);
+		return -EINVAL;
+	}
+	/* Set the LRCLK period */
+	snd_soc_component_update_bits(component,
+				      CS42L42_FSYNC_P_LOWER,
+				      CS42L42_FSYNC_PERIOD_MASK,
+				      CS42L42_FRAC0_VAL(fsync - 1) <<
+				      CS42L42_FSYNC_PERIOD_SHIFT);
+	snd_soc_component_update_bits(component,
+				      CS42L42_FSYNC_P_UPPER,
+				      CS42L42_FSYNC_PERIOD_MASK,
+				      CS42L42_FRAC1_VAL(fsync - 1) <<
+				      CS42L42_FSYNC_PERIOD_SHIFT);
+	/* Set the LRCLK to 50% duty cycle */
+	fsync = fsync / 2;
+	snd_soc_component_update_bits(component,
+				      CS42L42_FSYNC_PW_LOWER,
+				      CS42L42_FSYNC_PULSE_WIDTH_MASK,
+				      CS42L42_FRAC0_VAL(fsync - 1) <<
+				      CS42L42_FSYNC_PULSE_WIDTH_SHIFT);
+	snd_soc_component_update_bits(component,
+				      CS42L42_FSYNC_PW_UPPER,
+				      CS42L42_FSYNC_PULSE_WIDTH_MASK,
+				      CS42L42_FRAC1_VAL(fsync - 1) <<
+				      CS42L42_FSYNC_PULSE_WIDTH_SHIFT);
+
+	return 0;
+}
 
 static int cs42l42_set_dai_fmt(struct snd_soc_dai *codec_dai, unsigned int fmt)
 {
@@ -891,13 +909,12 @@ static int cs42l42_pcm_hw_params(struct snd_pcm_substream *substream,
 	struct cs42l42_private *cs42l42 = snd_soc_component_get_drvdata(component);
 	unsigned int channels = params_channels(params);
 	unsigned int width = (params_width(params) / 8) - 1;
+	unsigned int sample_rate = params_rate(params);
 	unsigned int slot_width = 0;
 	unsigned int val = 0;
 	unsigned int bclk;
 	int ret;
 
-	cs42l42->srate = params_rate(params);
-
 	if (cs42l42->bclk_ratio) {
 		/* machine driver has set the BCLK/samp-rate ratio */
 		bclk = cs42l42->bclk_ratio * params_rate(params);
@@ -954,11 +971,15 @@ static int cs42l42_pcm_hw_params(struct snd_pcm_substream *substream,
 		break;
 	}
 
-	ret = cs42l42_pll_config(component, bclk);
+	ret = cs42l42_pll_config(component, bclk, sample_rate);
 	if (ret)
 		return ret;
 
-	cs42l42_src_config(component, params_rate(params));
+	ret = cs42l42_asp_config(component, bclk, sample_rate);
+	if (ret)
+		return ret;
+
+	cs42l42_src_config(component, sample_rate);
 
 	return 0;
 }
@@ -998,7 +1019,7 @@ static int cs42l42_set_bclk_ratio(struct snd_soc_dai *dai,
 	return 0;
 }
 
-static int cs42l42_mute_stream(struct snd_soc_dai *dai, int mute, int stream)
+int cs42l42_mute_stream(struct snd_soc_dai *dai, int mute, int stream)
 {
 	struct snd_soc_component *component = dai->component;
 	struct cs42l42_private *cs42l42 = snd_soc_component_get_drvdata(component);
@@ -1091,6 +1112,7 @@ static int cs42l42_mute_stream(struct snd_soc_dai *dai, int mute, int stream)
 
 	return 0;
 }
+EXPORT_SYMBOL_NS_GPL(cs42l42_mute_stream, SND_SOC_CS42L42_CORE);
 
 #define CS42L42_FORMATS (SNDRV_PCM_FMTBIT_S16_LE |\
 			 SNDRV_PCM_FMTBIT_S24_LE |\
@@ -1633,7 +1655,7 @@ static const struct cs42l42_irq_params irq_params_table[] = {
 		CS42L42_TSRS_PLUG_VAL_MASK}
 };
 
-static irqreturn_t cs42l42_irq_thread(int irq, void *data)
+irqreturn_t cs42l42_irq_thread(int irq, void *data)
 {
 	struct cs42l42_private *cs42l42 = (struct cs42l42_private *)data;
 	unsigned int stickies[12];
@@ -1642,9 +1664,11 @@ static irqreturn_t cs42l42_irq_thread(int irq, void *data)
 	unsigned int current_button_status;
 	unsigned int i;
 
+	pm_runtime_get_sync(cs42l42->dev);
 	mutex_lock(&cs42l42->irq_lock);
 	if (cs42l42->suspended || !cs42l42->init_done) {
 		mutex_unlock(&cs42l42->irq_lock);
+		pm_runtime_put_autosuspend(cs42l42->dev);
 		return IRQ_NONE;
 	}
 
@@ -1747,9 +1771,12 @@ static irqreturn_t cs42l42_irq_thread(int irq, void *data)
 	}
 
 	mutex_unlock(&cs42l42->irq_lock);
+	pm_runtime_mark_last_busy(cs42l42->dev);
+	pm_runtime_put_autosuspend(cs42l42->dev);
 
 	return IRQ_HANDLED;
 }
+EXPORT_SYMBOL_NS_GPL(cs42l42_irq_thread, SND_SOC_CS42L42_CORE);
 
 static void cs42l42_set_interrupt_masks(struct cs42l42_private *cs42l42)
 {
@@ -2125,6 +2152,9 @@ int cs42l42_suspend(struct device *dev)
 	u8 save_regs[ARRAY_SIZE(cs42l42_shutdown_seq)];
 	int i, ret;
 
+	if (!cs42l42->init_done)
+		return 0;
+
 	/*
 	 * Wait for threaded irq handler to be idle and stop it processing
 	 * future interrupts. This ensures a safe disable if the interrupt
@@ -2185,6 +2215,9 @@ int cs42l42_resume(struct device *dev)
 	struct cs42l42_private *cs42l42 = dev_get_drvdata(dev);
 	int ret;
 
+	if (!cs42l42->init_done)
+		return 0;
+
 	/*
 	 * If jack was unplugged and re-plugged during suspend it could
 	 * have changed type but the tip-sense state hasn't changed.
@@ -2369,6 +2402,18 @@ int cs42l42_init(struct cs42l42_private *cs42l42)
 	if (ret != 0)
 		goto err_shutdown;
 
+	/*
+	 * SRC power is linked to ASP power so doesn't work in Soundwire mode.
+	 * Override it and use DAPM to control SRC power for Soundwire.
+	 */
+	if (cs42l42->sdw_peripheral) {
+		regmap_update_bits(cs42l42->regmap, CS42L42_PWR_CTL2,
+				   CS42L42_SRC_PDN_OVERRIDE_MASK |
+				   CS42L42_DAC_SRC_PDNB_MASK |
+				   CS42L42_ADC_SRC_PDNB_MASK,
+				   CS42L42_SRC_PDN_OVERRIDE_MASK);
+	}
+
 	/* Setup headset detection */
 	cs42l42_setup_hs_type_detect(cs42l42);
 

sound/soc/codecs/cs42l42.h

@@ -18,6 +18,7 @@
 #include <linux/mutex.h>
 #include <linux/regmap.h>
 #include <linux/regulator/consumer.h>
+#include <linux/soundwire/sdw.h>
 #include <sound/jack.h>
 #include <sound/cs42l42.h>
 #include <sound/soc-component.h>
@@ -30,13 +31,14 @@ struct  cs42l42_private {
 	struct gpio_desc *reset_gpio;
 	struct completion pdn_done;
 	struct snd_soc_jack *jack;
+	struct sdw_slave *sdw_peripheral;
 	struct mutex irq_lock;
 	int devid;
 	int irq;
 	int pll_config;
 	u32 sclk;
+	u32 sample_rate;
 	u32 bclk_ratio;
-	u32 srate;
 	u8 plug_state;
 	u8 hs_type;
 	u8 ts_inv;
@@ -62,6 +64,11 @@ extern struct snd_soc_dai_driver cs42l42_dai;
 bool cs42l42_readable_register(struct device *dev, unsigned int reg);
 bool cs42l42_volatile_register(struct device *dev, unsigned int reg);
 
+int cs42l42_pll_config(struct snd_soc_component *component,
+		       unsigned int clk, unsigned int sample_rate);
+void cs42l42_src_config(struct snd_soc_component *component, unsigned int sample_rate);
+int cs42l42_mute_stream(struct snd_soc_dai *dai, int mute, int stream);
+irqreturn_t cs42l42_irq_thread(int irq, void *data);
 int cs42l42_suspend(struct device *dev);
 int cs42l42_resume(struct device *dev);
 void cs42l42_resume_restore(struct device *dev);