2022-06-06 19:34:06

by Martin Povišer

[permalink] [raw]
Subject: [RFC PATCH v2 3/5] ASoC: apple: Add MCA platform driver for Apple SoCs

Add ASoC platform driver for the MCA peripheral found on Apple M1 and
other chips.

Signed-off-by: Martin Povišer <[email protected]>
---
sound/soc/Kconfig | 1 +
sound/soc/Makefile | 1 +
sound/soc/apple/Kconfig | 9 +
sound/soc/apple/Makefile | 3 +
sound/soc/apple/mca.c | 1122 ++++++++++++++++++++++++++++++++++++++
5 files changed, 1136 insertions(+)
create mode 100644 sound/soc/apple/Kconfig
create mode 100644 sound/soc/apple/Makefile
create mode 100644 sound/soc/apple/mca.c

diff --git a/sound/soc/Kconfig b/sound/soc/Kconfig
index 5dcf77af07af..aec82db3114b 100644
--- a/sound/soc/Kconfig
+++ b/sound/soc/Kconfig
@@ -61,6 +61,7 @@ config SND_SOC_ACPI
# All the supported SoCs
source "sound/soc/adi/Kconfig"
source "sound/soc/amd/Kconfig"
+source "sound/soc/apple/Kconfig"
source "sound/soc/atmel/Kconfig"
source "sound/soc/au1x/Kconfig"
source "sound/soc/bcm/Kconfig"
diff --git a/sound/soc/Makefile b/sound/soc/Makefile
index a7b37c06dc43..706dfbc28a6d 100644
--- a/sound/soc/Makefile
+++ b/sound/soc/Makefile
@@ -29,6 +29,7 @@ obj-$(CONFIG_SND_SOC_ACPI) += snd-soc-acpi.o
obj-$(CONFIG_SND_SOC) += snd-soc-core.o
obj-$(CONFIG_SND_SOC) += codecs/
obj-$(CONFIG_SND_SOC) += generic/
+obj-$(CONFIG_SND_SOC) += apple/
obj-$(CONFIG_SND_SOC) += adi/
obj-$(CONFIG_SND_SOC) += amd/
obj-$(CONFIG_SND_SOC) += atmel/
diff --git a/sound/soc/apple/Kconfig b/sound/soc/apple/Kconfig
new file mode 100644
index 000000000000..0ba955657e98
--- /dev/null
+++ b/sound/soc/apple/Kconfig
@@ -0,0 +1,9 @@
+config SND_SOC_APPLE_MCA
+ tristate "Apple Silicon MCA driver"
+ depends on ARCH_APPLE || COMPILE_TEST
+ select SND_DMAENGINE_PCM
+ select COMMON_CLK
+ default ARCH_APPLE
+ help
+ This option enables an ASoC platform driver for MCA peripherals found
+ on Apple Silicon SoCs.
diff --git a/sound/soc/apple/Makefile b/sound/soc/apple/Makefile
new file mode 100644
index 000000000000..7a30bf452817
--- /dev/null
+++ b/sound/soc/apple/Makefile
@@ -0,0 +1,3 @@
+snd-soc-apple-mca-objs := mca.o
+
+obj-$(CONFIG_SND_SOC_APPLE_MCA) += snd-soc-apple-mca.o
diff --git a/sound/soc/apple/mca.c b/sound/soc/apple/mca.c
new file mode 100644
index 000000000000..c53c9367efa5
--- /dev/null
+++ b/sound/soc/apple/mca.c
@@ -0,0 +1,1122 @@
+/*
+ * Apple SoCs MCA driver
+ *
+ * Copyright (C) The Asahi Linux Contributors
+ *
+ * The MCA peripheral is made up of a number of identical units called clusters.
+ * Each cluster has its separate clock parent, SYNC signal generator, carries
+ * four SERDES units and has a dedicated I2S port on the SoC's periphery.
+ *
+ * The clusters can operate independently, or can be combined together in a
+ * configurable manner. We mostly treat them as self-contained independent
+ * units and don't configure any cross-cluster connections except for the I2S
+ * ports. The I2S ports can be routed to any of the clusters (irrespective
+ * of their native cluster). We map this onto ASoC's (DPCM) notion of backend
+ * and frontend DAIs. The 'cluster guts' are frontends which are dynamically
+ * routed to backend I2S ports.
+ *
+ * DAI references in devicetree are resolved as backends. The machine driver
+ * makes up some routing to the frontends in the DAPM paths it supplies, which
+ * can mostly be arbitrary.
+ */
+
+#include <linux/clk.h>
+#include <linux/dma-mapping.h>
+#include <linux/init.h>
+#include <linux/bitfield.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_clk.h>
+#include <linux/of_dma.h>
+#include <linux/platform_device.h>
+#include <linux/pm_domain.h>
+#include <linux/regmap.h>
+#include <linux/reset.h>
+#include <linux/slab.h>
+
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+#include <sound/dmaengine_pcm.h>
+
+#define USE_RXB_FOR_CAPTURE
+
+/* relative to cluster base */
+#define REG_STATUS 0x0
+#define STATUS_MCLK_EN BIT(0)
+#define REG_MCLK_CONF 0x4
+#define MCLK_CONF_DIV GENMASK(11, 8)
+
+#define REG_SYNCGEN_STATUS 0x100
+#define SYNCGEN_STATUS_EN BIT(0)
+#define REG_SYNCGEN_MCLK_SEL 0x104
+#define SYNCGEN_MCLK_SEL GENMASK(3, 0)
+#define REG_SYNCGEN_HI_PERIOD 0x108
+#define REG_SYNCGEN_LO_PERIOD 0x10c
+
+#define REG_PORT_ENABLES 0x600
+#define PORT_ENABLES_CLOCKS GENMASK(2, 1)
+#define PORT_ENABLES_TX_DATA BIT(3)
+#define REG_PORT_CLOCK_SEL 0x604
+#define PORT_CLOCK_SEL GENMASK(11, 8)
+#define REG_PORT_DATA_SEL 0x608
+#define PORT_DATA_SEL_TXA(cl) (1 << ((cl)*2))
+#define PORT_DATA_SEL_TXB(cl) (2 << ((cl)*2))
+
+#define REG_INTSTATE 0x700
+#define REG_INTMASK 0x704
+
+/* bases of serdes units (relative to cluster) */
+#define CLUSTER_RXA_OFF 0x200
+#define CLUSTER_TXA_OFF 0x300
+#define CLUSTER_RXB_OFF 0x400
+#define CLUSTER_TXB_OFF 0x500
+
+#define CLUSTER_TX_OFF CLUSTER_TXA_OFF
+
+#ifndef USE_RXB_FOR_CAPTURE
+#define CLUSTER_RX_OFF CLUSTER_RXA_OFF
+#else
+#define CLUSTER_RX_OFF CLUSTER_RXB_OFF
+#endif
+
+/* relative to serdes unit base */
+#define REG_SERDES_STATUS 0x00
+#define SERDES_STATUS_EN BIT(0)
+#define SERDES_STATUS_RST BIT(1)
+#define REG_TX_SERDES_CONF 0x04
+#define REG_RX_SERDES_CONF 0x08
+#define SERDES_CONF_NCHANS GENMASK(3, 0)
+#define SERDES_CONF_WIDTH_MASK GENMASK(8, 4)
+#define SERDES_CONF_WIDTH_16BIT 0x40
+#define SERDES_CONF_WIDTH_20BIT 0x80
+#define SERDES_CONF_WIDTH_24BIT 0xc0
+#define SERDES_CONF_WIDTH_32BIT 0x100
+#define SERDES_CONF_BCLK_POL 0x400
+#define SERDES_CONF_LSB_FIRST 0x800
+#define SERDES_CONF_UNK1 BIT(12)
+#define SERDES_CONF_UNK2 BIT(13)
+#define SERDES_CONF_UNK3 BIT(14)
+#define SERDES_CONF_NO_DATA_FEEDBACK BIT(14)
+#define SERDES_CONF_SYNC_SEL GENMASK(18, 16)
+#define SERDES_CONF_SOME_RST BIT(19)
+#define REG_TX_SERDES_BITSTART 0x08
+#define REG_RX_SERDES_BITSTART 0x0c
+#define REG_TX_SERDES_SLOTMASK 0x0c
+#define REG_RX_SERDES_SLOTMASK 0x10
+#define REG_RX_SERDES_PORT 0x04
+
+/* relative to switch base */
+#define REG_DMA_ADAPTER_A(cl) (0x8000 * (cl))
+#define REG_DMA_ADAPTER_B(cl) (0x8000 * (cl) + 0x4000)
+#define DMA_ADAPTER_TX_LSB_PAD GENMASK(4, 0)
+#define DMA_ADAPTER_TX_NCHANS GENMASK(6, 5)
+#define DMA_ADAPTER_RX_MSB_PAD GENMASK(12, 8)
+#define DMA_ADAPTER_RX_NCHANS GENMASK(14, 13)
+#define DMA_ADAPTER_NCHANS GENMASK(22, 20)
+
+#define SWITCH_STRIDE 0x8000
+#define CLUSTER_STRIDE 0x4000
+
+#define MAX_NCLUSTERS 6
+
+#define APPLE_MCA_FMTBITS (SNDRV_PCM_FMTBIT_S16_LE | \
+ SNDRV_PCM_FMTBIT_S24_LE | \
+ SNDRV_PCM_FMTBIT_S32_LE)
+
+struct mca_cluster {
+ int no;
+ __iomem void *base;
+ struct mca_data *host;
+ struct device *pd_dev;
+ struct clk *clk_parent;
+ struct dma_chan *dma_chans[SNDRV_PCM_STREAM_LAST + 1];
+
+ bool port_started[SNDRV_PCM_STREAM_LAST + 1];
+ int port_driver;
+ bool clocks_in_use[SNDRV_PCM_STREAM_LAST + 1];
+ struct device_link *pd_link;
+
+ unsigned int set_sysclk;
+
+ int tdm_slots;
+ int tdm_slot_width;
+ unsigned int tdm_tx_mask;
+ unsigned int tdm_rx_mask;
+};
+
+struct mca_data {
+ struct device *dev;
+
+ __iomem void *switch_base;
+
+ struct device *pd_dev;
+ struct device_link *pd_link;
+
+ int nclusters;
+ struct mca_cluster clusters[];
+};
+
+static void mca_modify(struct mca_cluster *cl, int regoffset,
+ u32 mask, u32 val)
+{
+ __iomem void *ptr = cl->base + regoffset;
+ u32 newval;
+
+ newval = (val & mask) | (readl_relaxed(ptr) & ~mask);
+ writel_relaxed(newval, ptr);
+}
+
+/*
+ * Get the cluster of FE or BE DAI
+ */
+static struct mca_cluster *mca_dai_to_cluster(struct snd_soc_dai *dai)
+{
+ struct mca_data *mca = snd_soc_dai_get_drvdata(dai);
+ /*
+ * FE DAIs are 0 ... nclusters - 1
+ * BE DAIs are nclusters ... 2*nclusters - 1
+ */
+ int cluster_no = dai->id % mca->nclusters;
+
+ return &mca->clusters[cluster_no];
+}
+
+/* called before PCM trigger */
+static void mca_fe_early_trigger(struct snd_pcm_substream *substream,
+ int cmd, struct snd_soc_dai *dai)
+{
+ struct mca_cluster *cl = mca_dai_to_cluster(dai);
+ bool is_tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
+ int serdes_unit = is_tx ? CLUSTER_TX_OFF : CLUSTER_RX_OFF;
+ int serdes_conf = serdes_unit + (is_tx ? REG_TX_SERDES_CONF : REG_RX_SERDES_CONF);
+
+ switch (cmd) {
+ case SNDRV_PCM_TRIGGER_START:
+ case SNDRV_PCM_TRIGGER_RESUME:
+ case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+ mca_modify(cl, serdes_unit + REG_SERDES_STATUS,
+ SERDES_STATUS_EN | SERDES_STATUS_RST,
+ SERDES_STATUS_RST);
+ mca_modify(cl, serdes_conf,
+ SERDES_CONF_SOME_RST, SERDES_CONF_SOME_RST);
+ (void) readl_relaxed(cl->base + serdes_conf);
+ mca_modify(cl, serdes_conf,
+ SERDES_STATUS_RST, 0);
+ WARN_ON(readl_relaxed(cl->base + REG_SERDES_STATUS)
+ & SERDES_STATUS_RST);
+ break;
+ default:
+ break;
+ }
+}
+
+static int mca_fe_trigger(struct snd_pcm_substream *substream,
+ int cmd, struct snd_soc_dai *dai)
+{
+ struct mca_cluster *cl = mca_dai_to_cluster(dai);
+ bool is_tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
+ int serdes_unit = is_tx ? CLUSTER_TX_OFF : CLUSTER_RX_OFF;
+
+ switch (cmd) {
+ case SNDRV_PCM_TRIGGER_START:
+ case SNDRV_PCM_TRIGGER_RESUME:
+ case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+ mca_modify(cl, serdes_unit + REG_SERDES_STATUS,
+ SERDES_STATUS_EN | SERDES_STATUS_RST,
+ SERDES_STATUS_EN);
+ break;
+
+ case SNDRV_PCM_TRIGGER_STOP:
+ case SNDRV_PCM_TRIGGER_SUSPEND:
+ case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+ mca_modify(cl, serdes_unit + REG_SERDES_STATUS,
+ SERDES_STATUS_EN, 0);
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int mca_fe_enable_clocks(struct mca_cluster *cl)
+{
+ struct mca_data *mca = cl->host;
+ int ret;
+
+ ret = clk_prepare_enable(cl->clk_parent);
+ if (ret) {
+ dev_err(mca->dev, "cluster %d: unable to enable clock parent: %d\n",
+ cl->no, ret);
+ return ret;
+ }
+
+ cl->pd_link = device_link_add(mca->dev, cl->pd_dev,
+ DL_FLAG_STATELESS | DL_FLAG_PM_RUNTIME |
+ DL_FLAG_RPM_ACTIVE);
+ if (!cl->pd_link) {
+ dev_err(mca->dev, "cluster %d: unable to prop-up power domain\n",
+ cl->no);
+ clk_disable_unprepare(cl->clk_parent);
+ return -EINVAL;
+ }
+
+ writel_relaxed(cl->no + 1,
+ cl->base + REG_SYNCGEN_MCLK_SEL);
+ mca_modify(cl, REG_SYNCGEN_STATUS,
+ SYNCGEN_STATUS_EN, SYNCGEN_STATUS_EN);
+ mca_modify(cl, REG_STATUS,
+ STATUS_MCLK_EN, STATUS_MCLK_EN);
+
+ return 0;
+}
+
+static void mca_fe_disable_clocks(struct mca_cluster *cl)
+{
+ mca_modify(cl, REG_SYNCGEN_STATUS,
+ SYNCGEN_STATUS_EN, 0);
+ mca_modify(cl, REG_STATUS,
+ STATUS_MCLK_EN, 0);
+
+ device_link_del(cl->pd_link);
+ clk_disable_unprepare(cl->clk_parent);
+}
+
+static bool mca_fe_clocks_in_use(struct mca_cluster *cl)
+{
+ struct mca_data *mca = cl->host;
+ struct mca_cluster *be_cl;
+ int stream, i;
+
+ for (i = 0; i < mca->nclusters; i++) {
+ be_cl = &mca->clusters[i];
+
+ if (be_cl->port_driver != cl->no)
+ continue;
+
+ for_each_pcm_streams(stream)
+ if (be_cl->clocks_in_use[stream])
+ return true;
+ }
+ return false;
+}
+
+static int mca_be_prepare(struct snd_pcm_substream *substream,
+ struct snd_soc_dai *dai)
+{
+ struct mca_cluster *cl = mca_dai_to_cluster(dai);
+ struct mca_data *mca = cl->host;
+ struct mca_cluster *fe_cl;
+ int ret;
+
+ if (cl->port_driver < 0)
+ return -EINVAL;
+
+ fe_cl = &mca->clusters[cl->port_driver];
+
+ /*
+ * Codecs require clocks at time of umute with the 'mute_stream' op.
+ * We need to enable them here at the latest (frontend prepare would
+ * be too late).
+ */
+ if (!mca_fe_clocks_in_use(fe_cl)) {
+ ret = mca_fe_enable_clocks(fe_cl);
+ if (ret < 0)
+ return ret;
+ }
+
+ cl->clocks_in_use[substream->stream] = true;
+
+ return 0;
+}
+
+static int mca_be_hw_free(struct snd_pcm_substream *substream,
+ struct snd_soc_dai *dai)
+{
+ struct mca_cluster *cl = mca_dai_to_cluster(dai);
+ struct mca_data *mca = cl->host;
+ struct mca_cluster *fe_cl;
+
+ if (cl->port_driver < 0)
+ return -EINVAL;
+
+ fe_cl = &mca->clusters[cl->port_driver];
+ if (!mca_fe_clocks_in_use(fe_cl))
+ return 0; /* Nothing to do */
+
+ cl->clocks_in_use[substream->stream] = false;
+
+ if (!mca_fe_clocks_in_use(fe_cl))
+ mca_fe_disable_clocks(fe_cl);
+
+ return 0;
+}
+
+static unsigned int mca_crop_mask(unsigned int mask, int nchans)
+{
+ while (hweight32(mask) > nchans)
+ mask &= ~(1 << __fls(mask));
+
+ return mask;
+}
+
+static int mca_configure_serdes(struct mca_cluster *cl, int serdes_unit,
+ unsigned int mask, int slots, int nchans, int slot_width,
+ bool is_tx, int port)
+{
+ u32 serdes_conf, serdes_conf_mask;
+
+ serdes_conf_mask = SERDES_CONF_WIDTH_MASK | SERDES_CONF_NCHANS;
+ serdes_conf = FIELD_PREP(SERDES_CONF_NCHANS, max(slots, 1) - 1);
+ switch (slot_width) {
+ case 16:
+ serdes_conf |= SERDES_CONF_WIDTH_16BIT;
+ break;
+ case 20:
+ serdes_conf |= SERDES_CONF_WIDTH_20BIT;
+ break;
+ case 24:
+ serdes_conf |= SERDES_CONF_WIDTH_24BIT;
+ break;
+ case 32:
+ serdes_conf |= SERDES_CONF_WIDTH_32BIT;
+ break;
+ default:
+ goto err;
+ }
+
+ serdes_conf_mask |= SERDES_CONF_SYNC_SEL;
+ serdes_conf |= FIELD_PREP(SERDES_CONF_SYNC_SEL, cl->no + 1);
+
+ if (is_tx) {
+ serdes_conf_mask |= SERDES_CONF_UNK1 | SERDES_CONF_UNK2 | SERDES_CONF_UNK3;
+ serdes_conf |= SERDES_CONF_UNK1 | SERDES_CONF_UNK2 | SERDES_CONF_UNK3;
+ } else {
+
+ serdes_conf_mask |= SERDES_CONF_UNK1 | SERDES_CONF_UNK2 | SERDES_CONF_UNK3
+ | SERDES_CONF_NO_DATA_FEEDBACK;
+ serdes_conf |= SERDES_CONF_UNK1 | SERDES_CONF_UNK2
+ | SERDES_CONF_NO_DATA_FEEDBACK;
+ }
+
+ mca_modify(cl, serdes_unit + (is_tx ? REG_TX_SERDES_CONF : REG_RX_SERDES_CONF),
+ serdes_conf_mask, serdes_conf);
+
+ if (is_tx) {
+ writel_relaxed(0xffffffff,
+ cl->base + serdes_unit + REG_TX_SERDES_SLOTMASK);
+ writel_relaxed(~((u32) mca_crop_mask(mask, nchans)),
+ cl->base + serdes_unit + REG_TX_SERDES_SLOTMASK + 0x4);
+ writel_relaxed(0xffffffff,
+ cl->base + serdes_unit + REG_TX_SERDES_SLOTMASK + 0x8);
+ writel_relaxed(~((u32) mask),
+ cl->base + serdes_unit + REG_TX_SERDES_SLOTMASK + 0xc);
+ } else {
+ writel_relaxed(0xffffffff,
+ cl->base + serdes_unit + REG_RX_SERDES_SLOTMASK);
+ writel_relaxed(~((u32) mask),
+ cl->base + serdes_unit + REG_RX_SERDES_SLOTMASK + 0x4);
+ writel_relaxed(1 << port,
+ cl->base + serdes_unit + REG_RX_SERDES_PORT);
+ }
+
+ return 0;
+
+err:
+ dev_err(cl->host->dev, "unsupported SERDES configuration requested (mask=0x%x slots=%d slot_width=%d)\n",
+ mask, slots, slot_width);
+ return -EINVAL;
+}
+
+static int mca_fe_set_tdm_slot(struct snd_soc_dai *dai, unsigned int tx_mask,
+ unsigned int rx_mask, int slots, int slot_width)
+{
+ struct mca_cluster *cl = mca_dai_to_cluster(dai);
+
+ cl->tdm_slots = slots;
+ cl->tdm_slot_width = slot_width;
+ cl->tdm_tx_mask = tx_mask;
+ cl->tdm_rx_mask = rx_mask;
+
+ return 0;
+}
+
+static int mca_fe_set_fmt(struct snd_soc_dai *dai,
+ unsigned int fmt)
+{
+ struct mca_cluster *cl = mca_dai_to_cluster(dai);
+ struct mca_data *mca = cl->host;
+ bool fpol_inv = false;
+ u32 serdes_conf = 0;
+ u32 bitstart;
+
+ if ((fmt & SND_SOC_DAIFMT_CLOCK_PROVIDER_MASK) !=
+ SND_SOC_DAIFMT_CBC_CFC)
+ goto err;
+
+ switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
+ case SND_SOC_DAIFMT_I2S:
+ fpol_inv = 0;
+ bitstart = 1;
+ break;
+ case SND_SOC_DAIFMT_LEFT_J:
+ fpol_inv = 1;
+ bitstart = 0;
+ break;
+ default:
+ goto err;
+ }
+
+ switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
+ case SND_SOC_DAIFMT_NB_IF:
+ case SND_SOC_DAIFMT_IB_IF:
+ fpol_inv ^= 1;
+ break;
+ }
+
+ switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
+ case SND_SOC_DAIFMT_NB_NF:
+ case SND_SOC_DAIFMT_NB_IF:
+ serdes_conf |= SERDES_CONF_BCLK_POL;
+ break;
+ }
+
+ if (!fpol_inv)
+ goto err;
+
+ mca_modify(cl, CLUSTER_TX_OFF + REG_TX_SERDES_CONF,
+ SERDES_CONF_BCLK_POL,
+ serdes_conf);
+ writel_relaxed(bitstart,
+ cl->base + CLUSTER_TX_OFF + REG_TX_SERDES_BITSTART);
+ mca_modify(cl, CLUSTER_RX_OFF + REG_RX_SERDES_CONF,
+ SERDES_CONF_BCLK_POL,
+ serdes_conf);
+ writel_relaxed(bitstart,
+ cl->base + CLUSTER_RX_OFF + REG_RX_SERDES_BITSTART);
+
+ return 0;
+
+err:
+ dev_err(mca->dev, "unsupported DAI format (0x%x) requested\n", fmt);
+ return -EINVAL;
+}
+
+static int mca_fe_set_sysclk(struct snd_soc_dai *dai, int clk_id,
+ unsigned int freq, int dir)
+{
+ struct mca_cluster *cl = mca_dai_to_cluster(dai);
+ int ret;
+
+ if (freq == cl->set_sysclk)
+ return 0;
+
+ if (mca_fe_clocks_in_use(cl))
+ return -EBUSY;
+
+ ret = clk_set_rate(cl->clk_parent, freq);
+ if (!ret)
+ cl->set_sysclk = freq;
+ return ret;
+}
+
+static int mca_fe_hw_params(struct snd_pcm_substream *substream,
+ struct snd_pcm_hw_params *params,
+ struct snd_soc_dai *dai)
+{
+ struct mca_cluster *cl = mca_dai_to_cluster(dai);
+ struct mca_data *mca = cl->host;
+ struct device *dev = mca->dev;
+ unsigned int samp_rate = params_rate(params);
+ bool is_tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
+ bool refine_tdm = false;
+ unsigned long bclk_ratio;
+ unsigned int tdm_slots, tdm_slot_width, tdm_mask;
+ u32 regval, pad;
+ int ret, nchans_ceiled;
+
+ if (!cl->tdm_slot_width) {
+ /*
+ * We were not given TDM settings from above, set initial
+ * guesses which will later be refined.
+ */
+ tdm_slot_width = params_width(params);
+ tdm_slots = params_channels(params);
+ refine_tdm = true;
+ } else {
+ tdm_slot_width = cl->tdm_slot_width;
+ tdm_slots = cl->tdm_slots;
+ tdm_mask = is_tx ? cl->tdm_tx_mask : cl->tdm_rx_mask;
+ }
+
+ if (cl->set_sysclk)
+ bclk_ratio = cl->set_sysclk / samp_rate;
+ else
+ bclk_ratio = tdm_slot_width * tdm_slots;
+
+ if (refine_tdm) {
+ int nchannels = params_channels(params);
+
+ if (nchannels > 2) {
+ dev_err(dev, "missing TDM for stream with over two channels\n");
+ return -EINVAL;
+ }
+
+ if ((bclk_ratio % nchannels) != 0) {
+ dev_err(dev, "BCLK ratio (%ld) not divisible by no of channels (%d)\n",
+ bclk_ratio, nchannels);
+ return -EINVAL;
+ }
+
+ tdm_slot_width = bclk_ratio / nchannels;
+
+ if (tdm_slot_width > 32 && nchannels == 1)
+ tdm_slot_width = 32;
+
+ if (tdm_slot_width < params_width(params)) {
+ dev_err(dev, "TDM slots too narrow (tdm=%d params=%d)\n",
+ tdm_slot_width, params_width(params));
+ return -EINVAL;
+ }
+
+ tdm_mask = (1 << tdm_slots) - 1;
+ }
+
+ ret = mca_configure_serdes(cl, is_tx ? CLUSTER_TX_OFF : CLUSTER_RX_OFF,
+ tdm_mask, tdm_slots, params_channels(params),
+ tdm_slot_width, is_tx, cl->no);
+ if (ret)
+ return ret;
+
+ pad = 32 - params_width(params);
+
+ /*
+ * TODO: Here the register semantics aren't clear.
+ */
+ nchans_ceiled = min_t(int, params_channels(params), 4);
+ regval = FIELD_PREP(DMA_ADAPTER_NCHANS, nchans_ceiled)
+ | FIELD_PREP(DMA_ADAPTER_TX_NCHANS, 0x2)
+ | FIELD_PREP(DMA_ADAPTER_RX_NCHANS, 0x2)
+ | FIELD_PREP(DMA_ADAPTER_TX_LSB_PAD, pad)
+ | FIELD_PREP(DMA_ADAPTER_RX_MSB_PAD, pad);
+
+#ifndef USE_RXB_FOR_CAPTURE
+ writel_relaxed(regval, mca->switch_base + REG_DMA_ADAPTER_A(cl->no));
+#else
+ if (is_tx)
+ writel_relaxed(regval, mca->switch_base + REG_DMA_ADAPTER_A(cl->no));
+ else
+ writel_relaxed(regval, mca->switch_base + REG_DMA_ADAPTER_B(cl->no));
+#endif
+
+ if (!mca_fe_clocks_in_use(cl)) {
+ /*
+ * Set up FSYNC duty cycle as even as possible.
+ */
+ writel_relaxed((bclk_ratio / 2) - 1, cl->base + REG_SYNCGEN_HI_PERIOD);
+ writel_relaxed(((bclk_ratio + 1) / 2) - 1, cl->base + REG_SYNCGEN_LO_PERIOD);
+ writel_relaxed(FIELD_PREP(MCLK_CONF_DIV, 0x1), cl->base + REG_MCLK_CONF);
+
+ ret = clk_set_rate(cl->clk_parent, bclk_ratio * samp_rate);
+ if (ret) {
+ dev_err(mca->dev, "cluster %d: unable to set clock parent: %d\n",
+ cl->no, ret);
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+
+static const struct snd_soc_dai_ops mca_fe_ops = {
+ .set_fmt = mca_fe_set_fmt,
+ .set_sysclk = mca_fe_set_sysclk,
+ .set_tdm_slot = mca_fe_set_tdm_slot,
+ .hw_params = mca_fe_hw_params,
+ .trigger = mca_fe_trigger,
+};
+
+static bool mca_be_started(struct mca_cluster *cl)
+{
+ int stream;
+
+ for_each_pcm_streams(stream)
+ if (cl->port_started[stream])
+ return true;
+ return false;
+}
+
+static int mca_be_startup(struct snd_pcm_substream *substream,
+ struct snd_soc_dai *dai)
+{
+ struct snd_soc_pcm_runtime *be = asoc_substream_to_rtd(substream);
+ struct snd_soc_pcm_runtime *fe;
+ struct mca_cluster *cl = mca_dai_to_cluster(dai);
+ struct mca_cluster *fe_cl;
+ struct mca_data *mca = cl->host;
+ struct snd_soc_dpcm *dpcm;
+
+ fe = NULL;
+
+ for_each_dpcm_fe(be, substream->stream, dpcm) {
+ if (fe && dpcm->fe != fe) {
+ dev_err(mca->dev, "many FE per one BE unsupported\n");
+ return -EINVAL;
+ }
+
+ fe = dpcm->fe;
+ }
+
+ if (!fe)
+ return -EINVAL;
+
+ fe_cl = mca_dai_to_cluster(asoc_rtd_to_cpu(fe, 0));
+
+ if (mca_be_started(cl)) {
+ /*
+ * Port is already started in the other direction.
+ * Check it isn't driven from different cluster.
+ */
+ if (fe_cl->no != cl->port_driver)
+ return -EINVAL;
+
+ cl->port_started[substream->stream] = true;
+ return 0;
+ }
+
+ writel_relaxed(PORT_ENABLES_CLOCKS | PORT_ENABLES_TX_DATA,
+ cl->base + REG_PORT_ENABLES);
+ writel_relaxed(FIELD_PREP(PORT_CLOCK_SEL, fe_cl->no + 1),
+ cl->base + REG_PORT_CLOCK_SEL);
+ writel_relaxed(PORT_DATA_SEL_TXA(fe_cl->no),
+ cl->base + REG_PORT_DATA_SEL);
+ cl->port_driver = fe_cl->no;
+ cl->port_started[substream->stream] = true;
+
+ return 0;
+}
+
+static void mca_be_shutdown(struct snd_pcm_substream *substream,
+ struct snd_soc_dai *dai)
+{
+ struct mca_cluster *cl = mca_dai_to_cluster(dai);
+
+ cl->port_started[substream->stream] = false;
+
+ if (!mca_be_started(cl)) {
+ /*
+ * Were we the last direction to shutdown?
+ * Turn off the lights.
+ */
+ writel_relaxed(0, cl->base + REG_PORT_ENABLES);
+ writel_relaxed(0, cl->base + REG_PORT_DATA_SEL);
+ cl->port_driver = -1;
+ }
+}
+
+static const struct snd_soc_dai_ops mca_be_ops = {
+ .prepare = mca_be_prepare,
+ .hw_free = mca_be_hw_free,
+ .startup = mca_be_startup,
+ .shutdown = mca_be_shutdown,
+};
+
+static int mca_set_runtime_hwparams(struct snd_soc_component *component,
+ struct snd_pcm_substream *substream, struct dma_chan *chan)
+{
+ struct device *dma_dev = chan->device->dev;
+ struct snd_dmaengine_dai_dma_data dma_data = {};
+ int ret;
+
+ struct snd_pcm_hardware hw;
+
+ memset(&hw, 0, sizeof(hw));
+
+ hw.info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
+ SNDRV_PCM_INFO_INTERLEAVED;
+ hw.periods_min = 2;
+ hw.periods_max = UINT_MAX;
+ hw.period_bytes_min = 256;
+ hw.period_bytes_max = dma_get_max_seg_size(dma_dev);
+ hw.buffer_bytes_max = SIZE_MAX;
+ hw.fifo_size = 16;
+
+ ret = snd_dmaengine_pcm_refine_runtime_hwparams(substream,
+ &dma_data, &hw, chan);
+
+ if (ret)
+ return ret;
+
+ return snd_soc_set_runtime_hwparams(substream, &hw);
+}
+
+static int mca_pcm_open(struct snd_soc_component *component,
+ struct snd_pcm_substream *substream)
+{
+ struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
+ struct mca_cluster *cl = mca_dai_to_cluster(asoc_rtd_to_cpu(rtd, 0));
+ struct dma_chan *chan = cl->dma_chans[substream->stream];
+ int ret;
+
+ if (rtd->dai_link->no_pcm)
+ return 0;
+
+ ret = mca_set_runtime_hwparams(component, substream, chan);
+ if (ret)
+ return ret;
+
+ return snd_dmaengine_pcm_open(substream, chan);
+}
+
+static int mca_hw_params(struct snd_soc_component *component,
+ struct snd_pcm_substream *substream,
+ struct snd_pcm_hw_params *params)
+{
+ struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
+ struct dma_chan *chan = snd_dmaengine_pcm_get_chan(substream);
+ struct dma_slave_config slave_config;
+ int ret;
+
+ if (rtd->dai_link->no_pcm)
+ return 0;
+
+ memset(&slave_config, 0, sizeof(slave_config));
+ ret = snd_hwparams_to_dma_slave_config(substream, params, &slave_config);
+ if (ret < 0)
+ return ret;
+
+ if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+ slave_config.dst_port_window_size = min_t(u32, params_channels(params), 4);
+ else
+ slave_config.src_port_window_size = min_t(u32, params_channels(params), 4);
+
+ return dmaengine_slave_config(chan, &slave_config);
+}
+
+static int mca_close(struct snd_soc_component *component,
+ struct snd_pcm_substream *substream)
+{
+ struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
+
+ if (rtd->dai_link->no_pcm)
+ return 0;
+
+ return snd_dmaengine_pcm_close(substream);
+}
+
+static int mca_trigger(struct snd_soc_component *component,
+ struct snd_pcm_substream *substream, int cmd)
+{
+ struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
+
+ if (rtd->dai_link->no_pcm)
+ return 0;
+
+ /*
+ * Before we do the PCM trigger proper, insert an opportunity
+ * to reset the frontend's SERDES.
+ */
+ mca_fe_early_trigger(substream, cmd, asoc_rtd_to_cpu(rtd, 0));
+
+ return snd_dmaengine_pcm_trigger(substream, cmd);
+}
+
+static snd_pcm_uframes_t mca_pointer(struct snd_soc_component *component,
+ struct snd_pcm_substream *substream)
+{
+ struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
+
+ if (rtd->dai_link->no_pcm)
+ return -ENOTSUPP;
+
+ return snd_dmaengine_pcm_pointer(substream);
+}
+
+static int mca_pcm_new(struct snd_soc_component *component,
+ struct snd_soc_pcm_runtime *rtd)
+{
+ struct mca_cluster *cl = mca_dai_to_cluster(asoc_rtd_to_cpu(rtd, 0));
+ unsigned int i;
+
+ if (rtd->dai_link->no_pcm)
+ return 0;
+
+ for_each_pcm_streams(i) {
+ struct snd_pcm_substream *substream = rtd->pcm->streams[i].substream;
+ struct dma_chan *chan = cl->dma_chans[i];
+
+ if (!substream)
+ continue;
+
+ if (!chan) {
+ dev_err(component->dev, "missing DMA channel for stream %d on SERDES %d\n",
+ i, cl->no);
+ return -EINVAL;
+ }
+
+ snd_pcm_set_managed_buffer(substream, SNDRV_DMA_TYPE_DEV_IRAM,
+ chan->device->dev, 512*1024*6,
+ SIZE_MAX);
+ }
+
+ return 0;
+}
+
+static const struct snd_soc_component_driver mca_component = {
+ .name = "apple-mca",
+ .open = mca_pcm_open,
+ .close = mca_close,
+ .hw_params = mca_hw_params,
+ .trigger = mca_trigger,
+ .pointer = mca_pointer,
+ .pcm_construct = mca_pcm_new,
+};
+
+static void apple_mca_release(struct mca_data *mca)
+{
+ int i, stream;
+
+ for (i = 0; i < mca->nclusters; i++) {
+ struct mca_cluster *cl = &mca->clusters[i];
+
+ for_each_pcm_streams(stream) {
+ if (IS_ERR_OR_NULL(cl->dma_chans[stream]))
+ continue;
+
+ dma_release_channel(cl->dma_chans[stream]);
+ }
+
+ if (!IS_ERR_OR_NULL(cl->clk_parent))
+ clk_put(cl->clk_parent);
+
+ if (!IS_ERR_OR_NULL(cl->pd_dev))
+ dev_pm_domain_detach(cl->pd_dev, true);
+ }
+
+ if (mca->pd_link)
+ device_link_del(mca->pd_link);
+
+ if (!IS_ERR_OR_NULL(mca->pd_dev))
+ dev_pm_domain_detach(mca->pd_dev, true);
+}
+
+static int apple_mca_probe(struct platform_device *pdev)
+{
+ struct mca_data *mca;
+ struct mca_cluster *clusters;
+ struct snd_soc_dai_driver *dai_drivers;
+ struct resource *res;
+ void __iomem *base;
+ int nclusters;
+ int ret, i;
+
+ base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
+ if (IS_ERR(base))
+ return PTR_ERR(base);
+
+ if (resource_size(res) < CLUSTER_STRIDE)
+ return -EINVAL;
+ nclusters = (resource_size(res) - CLUSTER_STRIDE) / CLUSTER_STRIDE + 1;
+
+ mca = devm_kzalloc(&pdev->dev, struct_size(mca, clusters, nclusters),
+ GFP_KERNEL);
+ if (!mca)
+ return -ENOMEM;
+ mca->dev = &pdev->dev;
+ mca->nclusters = nclusters;
+ platform_set_drvdata(pdev, mca);
+ clusters = mca->clusters;
+
+ mca->switch_base = devm_platform_ioremap_resource_byname(pdev, "switch");
+ if (IS_ERR(mca->switch_base))
+ return PTR_ERR(mca->switch_base);
+
+ {
+ /*
+ * TODO: The only reset domain which seems to have an effect is
+ * AUDIO_P, which is shared with ADMAC (at minimum) and so can only
+ * be triggered non-exclusively.
+ */
+ struct reset_control *rst;
+
+ rst = of_reset_control_array_get(pdev->dev.of_node, true, true, false);
+ if (IS_ERR(rst)) {
+ dev_err(&pdev->dev, "unable to obtain reset control: %ld\n",
+ PTR_ERR(rst));
+ } else if (rst) {
+ reset_control_reset(rst);
+ reset_control_put(rst);
+ }
+ }
+
+ dai_drivers = devm_kzalloc(&pdev->dev, sizeof(*dai_drivers) * 2 * nclusters,
+ GFP_KERNEL);
+ if (!dai_drivers)
+ return -ENOMEM;
+
+ mca->pd_dev = dev_pm_domain_attach_by_id(&pdev->dev, 0);
+ if (IS_ERR(mca->pd_dev))
+ return -EINVAL;
+
+ /*
+ * TODO: need cleanup?
+ */
+ mca->pd_link = device_link_add(&pdev->dev, mca->pd_dev,
+ DL_FLAG_STATELESS | DL_FLAG_PM_RUNTIME |
+ DL_FLAG_RPM_ACTIVE);
+ if (!mca->pd_link) {
+ ret = -EINVAL;
+ goto err_release;
+ }
+
+ for (i = 0; i < nclusters; i++) {
+ struct mca_cluster *cl = &clusters[i];
+ struct snd_soc_dai_driver *fe = &dai_drivers[mca->nclusters + i];
+ struct snd_soc_dai_driver *be = &dai_drivers[i];
+ int stream;
+
+ cl->host = mca;
+ cl->no = i;
+ cl->base = base + CLUSTER_STRIDE * i;
+ cl->port_driver = -1;
+ cl->clk_parent = of_clk_get(pdev->dev.of_node, i);
+ if (IS_ERR(cl->clk_parent)) {
+ dev_err(&pdev->dev, "unable to obtain clock %d: %ld\n",
+ i, PTR_ERR(cl->clk_parent));
+ ret = PTR_ERR(cl->clk_parent);
+ goto err_release;
+ }
+ cl->pd_dev = dev_pm_domain_attach_by_id(&pdev->dev, i + 1);
+ if (IS_ERR(cl->pd_dev)) {
+ dev_err(&pdev->dev, "unable to obtain cluster %d PD: %ld\n",
+ i, PTR_ERR(cl->pd_dev));
+ ret = PTR_ERR(cl->pd_dev);
+ goto err_release;
+ }
+
+ for_each_pcm_streams(stream) {
+ struct dma_chan *chan;
+ bool is_tx = (stream == SNDRV_PCM_STREAM_PLAYBACK);
+#ifndef USE_RXB_FOR_CAPTURE
+ char *name = devm_kasprintf(&pdev->dev, GFP_KERNEL,
+ is_tx ? "tx%da" : "rx%da", i);
+#else
+ char *name = devm_kasprintf(&pdev->dev, GFP_KERNEL,
+ is_tx ? "tx%da" : "rx%db", i);
+#endif
+
+ chan = of_dma_request_slave_channel(pdev->dev.of_node, name);
+ if (IS_ERR(chan)) {
+ if (PTR_ERR(chan) != -EPROBE_DEFER)
+ dev_err(&pdev->dev, "no %s DMA channel: %ld\n",
+ name, PTR_ERR(chan));
+
+ ret = PTR_ERR(chan);
+ goto err_release;
+ }
+
+ cl->dma_chans[stream] = chan;
+ }
+
+ fe->id = i;
+ fe->name = devm_kasprintf(&pdev->dev, GFP_KERNEL,
+ "mca-pcm-%d", i);
+ if (!fe->name) {
+ ret = -ENOMEM;
+ goto err_release;
+ }
+ fe->ops = &mca_fe_ops;
+ fe->playback.channels_min = 1;
+ fe->playback.channels_max = 32;
+ fe->playback.rates = SNDRV_PCM_RATE_8000_192000;
+ fe->playback.formats = APPLE_MCA_FMTBITS;
+ fe->capture.channels_min = 1;
+ fe->capture.channels_max = 32;
+ fe->capture.rates = SNDRV_PCM_RATE_8000_192000;
+ fe->capture.formats = APPLE_MCA_FMTBITS;
+ fe->symmetric_rate = 1;
+
+ fe->playback.stream_name = devm_kasprintf(&pdev->dev, GFP_KERNEL,
+ "PCM%d TX", i);
+ fe->capture.stream_name = devm_kasprintf(&pdev->dev, GFP_KERNEL,
+ "PCM%d RX", i);
+
+ if (!fe->playback.stream_name || !fe->capture.stream_name) {
+ ret = -ENOMEM;
+ goto err_release;
+ }
+
+ be->id = i + nclusters;
+ be->name = devm_kasprintf(&pdev->dev, GFP_KERNEL,
+ "mca-i2s-%d", i);
+ if (!be->name) {
+ ret = -ENOMEM;
+ goto err_release;
+ }
+ be->ops = &mca_be_ops;
+ be->playback.channels_min = 1;
+ be->playback.channels_max = 32;
+ be->playback.rates = SNDRV_PCM_RATE_8000_192000;
+ be->playback.formats = APPLE_MCA_FMTBITS;
+ be->capture.channels_min = 1;
+ be->capture.channels_max = 32;
+ be->capture.rates = SNDRV_PCM_RATE_8000_192000;
+ be->capture.formats = APPLE_MCA_FMTBITS;
+
+ be->playback.stream_name = devm_kasprintf(&pdev->dev, GFP_KERNEL,
+ "I2S%d TX", i);
+ be->capture.stream_name = devm_kasprintf(&pdev->dev, GFP_KERNEL,
+ "I2S%d RX", i);
+ if (!be->playback.stream_name || !be->capture.stream_name) {
+ ret = -ENOMEM;
+ goto err_release;
+ }
+ }
+
+ ret = devm_snd_soc_register_component(&pdev->dev, &mca_component,
+ dai_drivers, nclusters * 2);
+ if (ret) {
+ dev_err(&pdev->dev, "unable to register ASoC component: %d\n", ret);
+ goto err_release;
+ }
+
+ return 0;
+
+err_release:
+ apple_mca_release(mca);
+ return ret;
+}
+
+static int apple_mca_remove(struct platform_device *pdev)
+{
+ struct mca_data *mca = platform_get_drvdata(pdev);
+
+ apple_mca_release(mca);
+ return 0;
+}
+
+static const struct of_device_id apple_mca_of_match[] = {
+ { .compatible = "apple,mca", },
+ {}
+};
+MODULE_DEVICE_TABLE(of, apple_mca_of_match);
+
+static struct platform_driver apple_mca_driver = {
+ .driver = {
+ .name = "apple-mca",
+ .owner = THIS_MODULE,
+ .of_match_table = apple_mca_of_match,
+ },
+ .probe = apple_mca_probe,
+ .remove = apple_mca_remove,
+};
+module_platform_driver(apple_mca_driver);
+
+MODULE_AUTHOR("Martin Povišer <[email protected]>");
+MODULE_DESCRIPTION("ASoC platform driver for Apple Silicon SoCs");
+MODULE_LICENSE("GPL");
--
2.33.0


2022-06-06 22:48:26

by Mark Brown

[permalink] [raw]
Subject: Re: [RFC PATCH v2 3/5] ASoC: apple: Add MCA platform driver for Apple SoCs

On Mon, Jun 06, 2022 at 09:19:08PM +0200, Martin Povišer wrote:

> +++ b/sound/soc/apple/mca.c
> @@ -0,0 +1,1122 @@
> +/*
> + * Apple SoCs MCA driver

Please add SPDX headers to all your files.

> + mca_modify(cl, serdes_conf,
> + SERDES_CONF_SOME_RST, SERDES_CONF_SOME_RST);
> + (void) readl_relaxed(cl->base + serdes_conf);

Please drop the cast, casts to/from void are generally a warning sign as
they're unneeded in C. If you want to document the barrier use a
comment or wrapper function.

> + /*
> + * Codecs require clocks at time of umute with the 'mute_stream' op.
> + * We need to enable them here at the latest (frontend prepare would
> + * be too late).
> + */
> + if (!mca_fe_clocks_in_use(fe_cl)) {
> + ret = mca_fe_enable_clocks(fe_cl);
> + if (ret < 0)
> + return ret;
> + }

This requirement is CODEC specific. It's fine to bodge around to
satisfy it though, especially given the restricted set of platforms this
can be used with.

> + fe_cl = &mca->clusters[cl->port_driver];
> + if (!mca_fe_clocks_in_use(fe_cl))
> + return 0; /* Nothing to do */
> +
> + cl->clocks_in_use[substream->stream] = false;
> +
> + if (!mca_fe_clocks_in_use(fe_cl))
> + mca_fe_disable_clocks(fe_cl);

Are you sure this doesn't need locking?


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2022-06-07 18:07:31

by Martin Povišer

[permalink] [raw]
Subject: Re: [RFC PATCH v2 3/5] ASoC: apple: Add MCA platform driver for Apple SoCs


> On 6. 6. 2022, at 22:17, Mark Brown <[email protected]> wrote:
>
> On Mon, Jun 06, 2022 at 09:19:08PM +0200, Martin Povišer wrote:
>
>> +++ b/sound/soc/apple/mca.c
>> @@ -0,0 +1,1122 @@
>> +/*
>> + * Apple SoCs MCA driver
>
> Please add SPDX headers to all your files.
>
>> + mca_modify(cl, serdes_conf,
>> + SERDES_CONF_SOME_RST, SERDES_CONF_SOME_RST);
>> + (void) readl_relaxed(cl->base + serdes_conf);
>
> Please drop the cast, casts to/from void are generally a warning sign as
> they're unneeded in C. If you want to document the barrier use a
> comment or wrapper function.
>
>> + /*
>> + * Codecs require clocks at time of umute with the 'mute_stream' op.
>> + * We need to enable them here at the latest (frontend prepare would
>> + * be too late).
>> + */
>> + if (!mca_fe_clocks_in_use(fe_cl)) {
>> + ret = mca_fe_enable_clocks(fe_cl);
>> + if (ret < 0)
>> + return ret;
>> + }
>
> This requirement is CODEC specific. It's fine to bodge around to
> satisfy it though, especially given the restricted set of platforms this
> can be used with.
>
>> + fe_cl = &mca->clusters[cl->port_driver];
>> + if (!mca_fe_clocks_in_use(fe_cl))
>> + return 0; /* Nothing to do */
>> +
>> + cl->clocks_in_use[substream->stream] = false;
>> +
>> + if (!mca_fe_clocks_in_use(fe_cl))
>> + mca_fe_disable_clocks(fe_cl);
>
> Are you sure this doesn't need locking?

I am not sure. I need to study what locking is already done by ALSA/ASoC.
I assume the two stream directions here don’t share a lock already...