XTFPGA boards provides an audio subsystem that consists of TI CDCE706
clock synthesizer, I2S transmitter and TLV320AIC23 audio codec.
I2S transmitter has MMIO-based interface that resembles that of the
OpenCores I2S transmitter. I2S transmitter is always a master on I2S
bus. There's no specialized audio DMA, sample data are transferred to
I2S transmitter FIFO by CPU through memory-mapped queue interface.
Signed-off-by: Max Filippov <jcmvbkbc(a)gmail.com>
---
Changes v2->v3:
- drop .owner = THIS_MODULE from the struct platform_driver initialization;
- rebase to 3.18-rc7.
Changes v1->v2:
- fix module name in the sound/soc/xtensa/Makefile;
- split PCM data transfer code and I2S interface setup code;
- move clock enabling/disabling to runtime PM code;
- document I2S interface RATIO field;
- rewrite I2S interface LEVEL field calculation to avoid overflows;
- drop select statements from Kconfig;
- document RCU usage for tx_substream;
- clean up code running in RCU read-side critical section;
- use threaded IRQ handler instead of IRQ + tasklet;
- remove empty PCM callback handlers;
- add const to static structures where applicable;
- use platform_set_drvdata instead of dev_set_drvdata;
- drop redundant error reporting code;
- use platform_get_irq instead of platform_get_resource;
- clean up xtfpga_i2s_remove;
- add comments.
.../devicetree/bindings/sound/cdns,xtfpga-i2s.txt | 18 +
MAINTAINERS | 1 +
sound/soc/Kconfig | 1 +
sound/soc/Makefile | 1 +
sound/soc/xtensa/Kconfig | 7 +
sound/soc/xtensa/Makefile | 3 +
sound/soc/xtensa/xtfpga-i2s.c | 675 +++++++++++++++++++++
7 files changed, 706 insertions(+)
create mode 100644 Documentation/devicetree/bindings/sound/cdns,xtfpga-i2s.txt
create mode 100644 sound/soc/xtensa/Kconfig
create mode 100644 sound/soc/xtensa/Makefile
create mode 100644 sound/soc/xtensa/xtfpga-i2s.c
diff --git a/Documentation/devicetree/bindings/sound/cdns,xtfpga-i2s.txt b/Documentation/devicetree/bindings/sound/cdns,xtfpga-i2s.txt
new file mode 100644
index 0000000..befd125
--- /dev/null
+++ b/Documentation/devicetree/bindings/sound/cdns,xtfpga-i2s.txt
@@ -0,0 +1,18 @@
+Bindings for I2S controller built into xtfpga Xtensa bitstreams.
+
+Required properties:
+- compatible: shall be "cdns,xtfpga-i2s".
+- reg: memory region (address and length) with device registers.
+- interrupts: interrupt for the device.
+- clocks: phandle to the clk used as master clock. I2S bus clock
+ is derived from it.
+
+Examples:
+
+ i2s0: xtfpga-i2s@0d080000 {
+ #sound-dai-cells = <0>;
+ compatible = "cdns,xtfpga-i2s";
+ reg = <0x0d080000 0x40>;
+ interrupts = <2 1>;
+ clocks = <&cdce706 4>;
+ };
diff --git a/MAINTAINERS b/MAINTAINERS
index ddb9ac8..f1eb40f 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -10628,6 +10628,7 @@ M: Max Filippov <jcmvbkbc(a)gmail.com>
L: linux-xtensa(a)linux-xtensa.org
S: Maintained
F: drivers/spi/spi-xtensa-xtfpga.c
+F: sound/soc/xtensa/xtfpga-i2s.c
YAM DRIVER FOR AX.25
M: Jean-Paul Roubelat <jpr(a)f6fbb.org>
diff --git a/sound/soc/Kconfig b/sound/soc/Kconfig
index 7d5d644..dcc79aa 100644
--- a/sound/soc/Kconfig
+++ b/sound/soc/Kconfig
@@ -55,6 +55,7 @@ source "sound/soc/spear/Kconfig"
source "sound/soc/tegra/Kconfig"
source "sound/soc/txx9/Kconfig"
source "sound/soc/ux500/Kconfig"
+source "sound/soc/xtensa/Kconfig"
# Supported codecs
source "sound/soc/codecs/Kconfig"
diff --git a/sound/soc/Makefile b/sound/soc/Makefile
index 865e090..5b3c8f6 100644
--- a/sound/soc/Makefile
+++ b/sound/soc/Makefile
@@ -36,3 +36,4 @@ obj-$(CONFIG_SND_SOC) += spear/
obj-$(CONFIG_SND_SOC) += tegra/
obj-$(CONFIG_SND_SOC) += txx9/
obj-$(CONFIG_SND_SOC) += ux500/
+obj-$(CONFIG_SND_SOC) += xtensa/
diff --git a/sound/soc/xtensa/Kconfig b/sound/soc/xtensa/Kconfig
new file mode 100644
index 0000000..c201beb
--- /dev/null
+++ b/sound/soc/xtensa/Kconfig
@@ -0,0 +1,7 @@
+config SND_SOC_XTFPGA_I2S
+ tristate "XTFPGA I2S master"
+ select REGMAP_MMIO
+ help
+ Say Y or M if you want to add support for codecs attached to the
+ I2S interface on XTFPGA daughter board. You will also need to select
+ the drivers for the rest of XTFPGA audio subsystem.
diff --git a/sound/soc/xtensa/Makefile b/sound/soc/xtensa/Makefile
new file mode 100644
index 0000000..15efbf9
--- /dev/null
+++ b/sound/soc/xtensa/Makefile
@@ -0,0 +1,3 @@
+snd-soc-xtfpga-i2s-objs := xtfpga-i2s.o
+
+obj-$(CONFIG_SND_SOC_XTFPGA_I2S) += snd-soc-xtfpga-i2s.o
diff --git a/sound/soc/xtensa/xtfpga-i2s.c b/sound/soc/xtensa/xtfpga-i2s.c
new file mode 100644
index 0000000..1cfb19e
--- /dev/null
+++ b/sound/soc/xtensa/xtfpga-i2s.c
@@ -0,0 +1,675 @@
+/*
+ * Xtfpga I2S controller driver
+ *
+ * Copyright (c) 2014 Cadence Design Systems Inc.
+ *
+ * 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 <linux/clk.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+
+#define DRV_NAME "xtfpga-i2s"
+
+#define XTFPGA_I2S_VERSION 0x00
+#define XTFPGA_I2S_CONFIG 0x04
+#define XTFPGA_I2S_INT_MASK 0x08
+#define XTFPGA_I2S_INT_STATUS 0x0c
+#define XTFPGA_I2S_CHAN0_DATA 0x10
+#define XTFPGA_I2S_CHAN1_DATA 0x14
+#define XTFPGA_I2S_CHAN2_DATA 0x18
+#define XTFPGA_I2S_CHAN3_DATA 0x1c
+
+#define XTFPGA_I2S_CONFIG_TX_ENABLE 0x1
+#define XTFPGA_I2S_CONFIG_INT_ENABLE 0x2
+#define XTFPGA_I2S_CONFIG_LEFT 0x4
+#define XTFPGA_I2S_CONFIG_RATIO_BASE 8
+#define XTFPGA_I2S_CONFIG_RATIO_MASK 0x0000ff00
+#define XTFPGA_I2S_CONFIG_RES_BASE 16
+#define XTFPGA_I2S_CONFIG_RES_MASK 0x003f0000
+#define XTFPGA_I2S_CONFIG_LEVEL_BASE 24
+#define XTFPGA_I2S_CONFIG_LEVEL_MASK 0x0f000000
+#define XTFPGA_I2S_CONFIG_CHANNEL_BASE 28
+
+#define XTFPGA_I2S_INT_UNDERRUN 0x1
+#define XTFPGA_I2S_INT_LEVEL 0x2
+#define XTFPGA_I2S_INT_VALID 0x3
+
+#define XTFPGA_I2S_FIFO_SIZE 8192
+
+/*
+ * I2S controller operation:
+ *
+ * Enabling TX: output 1 period of zeros (starting with left channel)
+ * and then queued data.
+ *
+ * Level status and interrupt: whenever FIFO level is below FIFO trigger,
+ * level status is 1 and an IRQ is asserted (if enabled).
+ *
+ * Underrun status and interrupt: whenever FIFO is empty, underrun status
+ * is 1 and an IRQ is asserted (if enabled).
+ */
+struct xtfpga_i2s {
+ struct device *dev;
+ struct clk *clk;
+ struct regmap *regmap;
+ void __iomem *regs;
+
+ /* current playback substream. NULL if not playing.
+ *
+ * Access to that field is synchronized between the interrupt handler
+ * and userspace through RCU.
+ *
+ * Interrupt handler (threaded part) does PIO on substream data in RCU
+ * read-side critical section. Trigger callback sets and clears the
+ * pointer when the playback is started and stopped with
+ * rcu_assign_pointer. When userspace is about to free the playback
+ * stream in the pcm_close callback it synchronizes with the interrupt
+ * handler by means of synchronize_rcu call.
+ */
+ struct snd_pcm_substream *tx_substream;
+ unsigned (*tx_fn)(struct xtfpga_i2s *i2s,
+ struct snd_pcm_runtime *runtime,
+ unsigned tx_ptr);
+ unsigned tx_ptr; /* next frame index in the sample buffer */
+
+ /* current fifo level estimate.
+ * Doesn't have to be perfectly accurate, but must be not less than
+ * the actual FIFO level in order to avoid stall on push attempt.
+ */
+ unsigned tx_fifo_level;
+
+ /* FIFO level at which level interrupt occurs */
+ unsigned tx_fifo_low;
+
+ /* maximal FIFO level */
+ unsigned tx_fifo_high;
+};
+
+static bool xtfpga_i2s_wr_reg(struct device *dev, unsigned int reg)
+{
+ return reg >= XTFPGA_I2S_CONFIG;
+}
+
+static bool xtfpga_i2s_rd_reg(struct device *dev, unsigned int reg)
+{
+ return reg < XTFPGA_I2S_CHAN0_DATA;
+}
+
+static bool xtfpga_i2s_volatile_reg(struct device *dev, unsigned int reg)
+{
+ return reg == XTFPGA_I2S_INT_STATUS;
+}
+
+static const struct regmap_config xtfpga_i2s_regmap_config = {
+ .reg_bits = 32,
+ .reg_stride = 4,
+ .val_bits = 32,
+ .max_register = XTFPGA_I2S_CHAN3_DATA,
+ .writeable_reg = xtfpga_i2s_wr_reg,
+ .readable_reg = xtfpga_i2s_rd_reg,
+ .volatile_reg = xtfpga_i2s_volatile_reg,
+ .cache_type = REGCACHE_FLAT,
+};
+
+/* Generate functions that do PIO from TX DMA area to FIFO for all supported
+ * stream formats.
+ * Functions will be called xtfpga_pcm_tx_<channels>x<sample bits>, e.g.
+ * xtfpga_pcm_tx_2x16 for 16-bit stereo.
+ *
+ * FIFO consists of 32-bit words, one word per channel, always 2 channels.
+ * If I2S interface is configured with smaller sample resolution, only
+ * the LSB of each word is used.
+ */
+#define xtfpga_pcm_tx_fn(channels, sample_bits) \
+static unsigned xtfpga_pcm_tx_##channels##x##sample_bits( \
+ struct xtfpga_i2s *i2s, struct snd_pcm_runtime *runtime, \
+ unsigned tx_ptr) \
+{ \
+ const u##sample_bits (*p)[channels] = \
+ (void *)runtime->dma_area; \
+\
+ for (; i2s->tx_fifo_level < i2s->tx_fifo_high; \
+ i2s->tx_fifo_level += 2) { \
+ iowrite32(p[tx_ptr][0], \
+ i2s->regs + XTFPGA_I2S_CHAN0_DATA); \
+ iowrite32(p[tx_ptr][channels - 1], \
+ i2s->regs + XTFPGA_I2S_CHAN0_DATA); \
+ if (++tx_ptr >= runtime->buffer_size) \
+ tx_ptr = 0; \
+ } \
+ return tx_ptr; \
+}
+
+xtfpga_pcm_tx_fn(1, 16)
+xtfpga_pcm_tx_fn(2, 16)
+xtfpga_pcm_tx_fn(1, 32)
+xtfpga_pcm_tx_fn(2, 32)
+
+#undef xtfpga_pcm_tx_fn
+
+static bool xtfpga_pcm_push_tx(struct xtfpga_i2s *i2s)
+{
+ struct snd_pcm_substream *tx_substream;
+ bool tx_active;
+
+ rcu_read_lock();
+ tx_substream = rcu_dereference(i2s->tx_substream);
+ tx_active = tx_substream && snd_pcm_running(tx_substream);
+ if (tx_active) {
+ unsigned tx_ptr = ACCESS_ONCE(i2s->tx_ptr);
+ unsigned new_tx_ptr = i2s->tx_fn(i2s, tx_substream->runtime,
+ tx_ptr);
+
+ cmpxchg(&i2s->tx_ptr, tx_ptr, new_tx_ptr);
+ }
+ rcu_read_unlock();
+
+ return tx_active;
+}
+
+static void xtfpga_pcm_refill_fifo(struct xtfpga_i2s *i2s)
+{
+ unsigned int_status;
+ unsigned i;
+
+ regmap_read(i2s->regmap, XTFPGA_I2S_INT_STATUS,
+ &int_status);
+
+ for (i = 0; i < 2; ++i) {
+ bool tx_active = xtfpga_pcm_push_tx(i2s);
+
+ regmap_write(i2s->regmap, XTFPGA_I2S_INT_STATUS,
+ XTFPGA_I2S_INT_VALID);
+ if (tx_active)
+ regmap_read(i2s->regmap, XTFPGA_I2S_INT_STATUS,
+ &int_status);
+
+ if (!tx_active ||
+ !(int_status & XTFPGA_I2S_INT_LEVEL))
+ break;
+
+ /* After the push the level IRQ is still asserted,
+ * means FIFO level is below tx_fifo_low. Estimate
+ * it as tx_fifo_low.
+ */
+ i2s->tx_fifo_level = i2s->tx_fifo_low;
+ }
+
+ if (!(int_status & XTFPGA_I2S_INT_LEVEL))
+ regmap_write(i2s->regmap, XTFPGA_I2S_INT_MASK,
+ XTFPGA_I2S_INT_VALID);
+ else if (!(int_status & XTFPGA_I2S_INT_UNDERRUN))
+ regmap_write(i2s->regmap, XTFPGA_I2S_INT_MASK,
+ XTFPGA_I2S_INT_UNDERRUN);
+
+ if (!(int_status & XTFPGA_I2S_INT_UNDERRUN))
+ regmap_update_bits(i2s->regmap, XTFPGA_I2S_CONFIG,
+ XTFPGA_I2S_CONFIG_INT_ENABLE |
+ XTFPGA_I2S_CONFIG_TX_ENABLE,
+ XTFPGA_I2S_CONFIG_INT_ENABLE |
+ XTFPGA_I2S_CONFIG_TX_ENABLE);
+ else
+ regmap_update_bits(i2s->regmap, XTFPGA_I2S_CONFIG,
+ XTFPGA_I2S_CONFIG_INT_ENABLE |
+ XTFPGA_I2S_CONFIG_TX_ENABLE, 0);
+}
+
+static irqreturn_t xtfpga_i2s_threaded_irq_handler(int irq, void *dev_id)
+{
+ struct xtfpga_i2s *i2s = dev_id;
+ struct snd_pcm_substream *tx_substream;
+ unsigned config, int_status, int_mask;
+
+ regmap_read(i2s->regmap, XTFPGA_I2S_CONFIG, &config);
+ regmap_read(i2s->regmap, XTFPGA_I2S_INT_MASK, &int_mask);
+ regmap_read(i2s->regmap, XTFPGA_I2S_INT_STATUS, &int_status);
+
+ if (!(config & XTFPGA_I2S_CONFIG_INT_ENABLE) ||
+ !(int_status & int_mask & XTFPGA_I2S_INT_VALID))
+ return IRQ_NONE;
+
+ /* Update FIFO level estimate in accordance with interrupt status
+ * register.
+ */
+ if (int_status & XTFPGA_I2S_INT_UNDERRUN) {
+ i2s->tx_fifo_level = 0;
+ regmap_update_bits(i2s->regmap, XTFPGA_I2S_CONFIG,
+ XTFPGA_I2S_CONFIG_TX_ENABLE, 0);
+ } else {
+ /* The FIFO isn't empty, but is below tx_fifo_low. Estimate
+ * it as tx_fifo_low.
+ */
+ i2s->tx_fifo_level = i2s->tx_fifo_low;
+ }
+
+ rcu_read_lock();
+ tx_substream = rcu_dereference(i2s->tx_substream);
+
+ if (tx_substream && snd_pcm_running(tx_substream)) {
+ snd_pcm_period_elapsed(tx_substream);
+ if (int_status & XTFPGA_I2S_INT_UNDERRUN)
+ dev_dbg_ratelimited(i2s->dev, "%s: underrun\n",
+ __func__);
+ }
+ rcu_read_unlock();
+
+ /* Refill FIFO, update allowed IRQ reasons, enable IRQ if FIFO is
+ * not empty.
+ */
+ xtfpga_pcm_refill_fifo(i2s);
+
+ return IRQ_HANDLED;
+}
+
+static int xtfpga_i2s_startup(struct snd_pcm_substream *substream,
+ struct snd_soc_dai *dai)
+{
+ struct xtfpga_i2s *i2s = snd_soc_dai_get_drvdata(dai);
+
+ snd_soc_dai_set_dma_data(dai, substream, i2s);
+ return 0;
+}
+
+static int xtfpga_i2s_hw_params(struct snd_pcm_substream *substream,
+ struct snd_pcm_hw_params *params,
+ struct snd_soc_dai *dai)
+{
+ struct xtfpga_i2s *i2s = snd_soc_dai_get_drvdata(dai);
+ unsigned srate = params_rate(params);
+ unsigned channels = params_channels(params);
+ unsigned period_size = params_period_size(params);
+ unsigned sample_size = snd_pcm_format_width(params_format(params));
+ unsigned freq, ratio, level;
+ int err;
+
+ regmap_update_bits(i2s->regmap, XTFPGA_I2S_CONFIG,
+ XTFPGA_I2S_CONFIG_RES_MASK,
+ sample_size << XTFPGA_I2S_CONFIG_RES_BASE);
+
+ freq = 256 * srate;
+ err = clk_set_rate(i2s->clk, freq);
+ if (err < 0)
+ return err;
+
+ /* ratio field of the config register controls MCLK->I2S clock
+ * derivation: I2S clock = MCLK / (2 * (ratio + 2)).
+ *
+ * So with MCLK = 256 * sample rate ratio is 0 for 32 bit stereo
+ * and 2 for 16 bit stereo.
+ */
+ ratio = (freq - (srate * sample_size * 8)) /
+ (srate * sample_size * 4);
+
+ regmap_update_bits(i2s->regmap, XTFPGA_I2S_CONFIG,
+ XTFPGA_I2S_CONFIG_RATIO_MASK,
+ ratio << XTFPGA_I2S_CONFIG_RATIO_BASE);
+
+ i2s->tx_fifo_low = XTFPGA_I2S_FIFO_SIZE / 2;
+
+ /* period_size * 2: FIFO always gets 2 samples per frame */
+ for (level = 1;
+ i2s->tx_fifo_low / 2 >= period_size * 2 &&
+ level < (XTFPGA_I2S_CONFIG_LEVEL_MASK >>
+ XTFPGA_I2S_CONFIG_LEVEL_BASE); ++level)
+ i2s->tx_fifo_low /= 2;
+
+ i2s->tx_fifo_high = 2 * i2s->tx_fifo_low;
+
+ regmap_update_bits(i2s->regmap, XTFPGA_I2S_CONFIG,
+ XTFPGA_I2S_CONFIG_LEVEL_MASK,
+ level << XTFPGA_I2S_CONFIG_LEVEL_BASE);
+
+ dev_dbg(i2s->dev,
+ "%s srate: %u, channels: %u, sample_size: %u, period_size: %u\n",
+ __func__, srate, channels, sample_size, period_size);
+ dev_dbg(i2s->dev, "%s freq: %u, ratio: %u, level: %u\n",
+ __func__, freq, ratio, level);
+
+ return 0;
+}
+
+static int xtfpga_i2s_set_fmt(struct snd_soc_dai *cpu_dai,
+ unsigned int fmt)
+{
+ if ((fmt & SND_SOC_DAIFMT_INV_MASK) != SND_SOC_DAIFMT_NB_NF)
+ return -EINVAL;
+ if ((fmt & SND_SOC_DAIFMT_MASTER_MASK) != SND_SOC_DAIFMT_CBS_CFS)
+ return -EINVAL;
+ if ((fmt & SND_SOC_DAIFMT_FORMAT_MASK) != SND_SOC_DAIFMT_I2S)
+ return -EINVAL;
+
+ return 0;
+}
+
+/* PCM */
+
+static const struct snd_pcm_hardware xtfpga_pcm_hardware = {
+ .info = SNDRV_PCM_INFO_INTERLEAVED |
+ SNDRV_PCM_INFO_MMAP_VALID |
+ SNDRV_PCM_INFO_BLOCK_TRANSFER,
+ .formats = SNDRV_PCM_FMTBIT_S16_LE |
+ SNDRV_PCM_FMTBIT_S32_LE,
+ .channels_min = 1,
+ .channels_max = 2,
+ .period_bytes_min = 2,
+ .period_bytes_max = XTFPGA_I2S_FIFO_SIZE / 2 * 8,
+ .periods_min = 2,
+ .periods_max = XTFPGA_I2S_FIFO_SIZE * 8 / 2,
+ .buffer_bytes_max = XTFPGA_I2S_FIFO_SIZE * 8,
+ .fifo_size = 16,
+};
+
+static int xtfpga_pcm_open(struct snd_pcm_substream *substream)
+{
+ struct snd_pcm_runtime *runtime = substream->runtime;
+ struct snd_soc_pcm_runtime *rtd = substream->private_data;
+ void *p;
+
+ snd_soc_set_runtime_hwparams(substream, &xtfpga_pcm_hardware);
+ p = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
+ runtime->private_data = p;
+
+ return 0;
+}
+
+static int xtfpga_pcm_close(struct snd_pcm_substream *substream)
+{
+ synchronize_rcu();
+ return 0;
+}
+
+static int xtfpga_pcm_hw_params(struct snd_pcm_substream *substream,
+ struct snd_pcm_hw_params *hw_params)
+{
+ int ret;
+ struct snd_pcm_runtime *runtime = substream->runtime;
+ struct xtfpga_i2s *i2s = runtime->private_data;
+ unsigned channels = params_channels(hw_params);
+
+ switch (channels) {
+ case 1:
+ case 2:
+ break;
+
+ default:
+ return -EINVAL;
+
+ }
+
+ switch (params_format(hw_params)) {
+ case SNDRV_PCM_FORMAT_S16_LE:
+ i2s->tx_fn = (channels == 1) ?
+ xtfpga_pcm_tx_1x16 :
+ xtfpga_pcm_tx_2x16;
+ break;
+
+ case SNDRV_PCM_FORMAT_S32_LE:
+ i2s->tx_fn = (channels == 1) ?
+ xtfpga_pcm_tx_1x32 :
+ xtfpga_pcm_tx_2x32;
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ ret = snd_pcm_lib_malloc_pages(substream,
+ params_buffer_bytes(hw_params));
+ return ret;
+}
+
+static int xtfpga_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
+{
+ int ret = 0;
+ struct snd_pcm_runtime *runtime = substream->runtime;
+ struct xtfpga_i2s *i2s = runtime->private_data;
+
+ switch (cmd) {
+ case SNDRV_PCM_TRIGGER_START:
+ case SNDRV_PCM_TRIGGER_RESUME:
+ case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+ ACCESS_ONCE(i2s->tx_ptr) = 0;
+ rcu_assign_pointer(i2s->tx_substream, substream);
+ xtfpga_pcm_refill_fifo(i2s);
+ break;
+
+ case SNDRV_PCM_TRIGGER_STOP:
+ case SNDRV_PCM_TRIGGER_SUSPEND:
+ case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+ rcu_assign_pointer(i2s->tx_substream, NULL);
+ break;
+
+ default:
+ ret = -EINVAL;
+ break;
+ }
+ return ret;
+}
+
+static snd_pcm_uframes_t xtfpga_pcm_pointer(struct snd_pcm_substream *substream)
+{
+ struct snd_pcm_runtime *runtime = substream->runtime;
+ struct xtfpga_i2s *i2s = runtime->private_data;
+ snd_pcm_uframes_t pos = ACCESS_ONCE(i2s->tx_ptr);
+
+ return pos < runtime->buffer_size ? pos : 0;
+}
+
+static int xtfpga_pcm_new(struct snd_soc_pcm_runtime *rtd)
+{
+ struct snd_card *card = rtd->card->snd_card;
+ size_t size = xtfpga_pcm_hardware.buffer_bytes_max;
+
+ return snd_pcm_lib_preallocate_pages_for_all(rtd->pcm,
+ SNDRV_DMA_TYPE_DEV,
+ card->dev, size, size);
+}
+
+static void xtfpga_pcm_free(struct snd_pcm *pcm)
+{
+ snd_pcm_lib_preallocate_free_for_all(pcm);
+}
+
+static const struct snd_pcm_ops xtfpga_pcm_ops = {
+ .open = xtfpga_pcm_open,
+ .close = xtfpga_pcm_close,
+ .ioctl = snd_pcm_lib_ioctl,
+ .hw_params = xtfpga_pcm_hw_params,
+ .trigger = xtfpga_pcm_trigger,
+ .pointer = xtfpga_pcm_pointer,
+};
+
+static const struct snd_soc_platform_driver xtfpga_soc_platform = {
+ .pcm_new = xtfpga_pcm_new,
+ .pcm_free = xtfpga_pcm_free,
+ .ops = &xtfpga_pcm_ops,
+};
+
+static const struct snd_soc_component_driver xtfpga_i2s_component = {
+ .name = DRV_NAME,
+};
+
+static const struct snd_soc_dai_ops xtfpga_i2s_dai_ops = {
+ .startup = xtfpga_i2s_startup,
+ .hw_params = xtfpga_i2s_hw_params,
+ .set_fmt = xtfpga_i2s_set_fmt,
+};
+
+static struct snd_soc_dai_driver xtfpga_i2s_dai[] = {
+ {
+ .name = "xtfpga-i2s",
+ .id = 0,
+ .playback = {
+ .channels_min = 1,
+ .channels_max = 2,
+ .rates = SNDRV_PCM_RATE_8000_96000,
+ .formats = SNDRV_PCM_FMTBIT_S16_LE |
+ SNDRV_PCM_FMTBIT_S32_LE,
+ },
+ .ops = &xtfpga_i2s_dai_ops,
+ },
+};
+
+static int xtfpga_i2s_runtime_suspend(struct device *dev)
+{
+ struct xtfpga_i2s *i2s = dev_get_drvdata(dev);
+
+ clk_disable_unprepare(i2s->clk);
+ return 0;
+}
+
+static int xtfpga_i2s_runtime_resume(struct device *dev)
+{
+ struct xtfpga_i2s *i2s = dev_get_drvdata(dev);
+ int ret;
+
+ ret = clk_prepare_enable(i2s->clk);
+ if (ret) {
+ dev_err(dev, "clk_prepare_enable failed: %d\n", ret);
+ return ret;
+ }
+ return 0;
+}
+
+static int xtfpga_i2s_probe(struct platform_device *pdev)
+{
+ struct xtfpga_i2s *i2s;
+ struct resource *mem;
+ int err, irq;
+
+ i2s = devm_kzalloc(&pdev->dev, sizeof(*i2s), GFP_KERNEL);
+ if (!i2s) {
+ err = -ENOMEM;
+ goto err;
+ }
+ platform_set_drvdata(pdev, i2s);
+ i2s->dev = &pdev->dev;
+ dev_dbg(&pdev->dev, "dev: %p, i2s: %p\n", &pdev->dev, i2s);
+
+ mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ i2s->regs = devm_ioremap_resource(&pdev->dev, mem);
+ if (IS_ERR(i2s->regs)) {
+ err = PTR_ERR(i2s->regs);
+ goto err;
+ }
+
+ i2s->regmap = devm_regmap_init_mmio(&pdev->dev, i2s->regs,
+ &xtfpga_i2s_regmap_config);
+ if (IS_ERR(i2s->regmap)) {
+ dev_err(&pdev->dev, "regmap init failed\n");
+ err = PTR_ERR(i2s->regmap);
+ goto err;
+ }
+
+ i2s->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(i2s->clk)) {
+ dev_err(&pdev->dev, "couldn't get clock\n");
+ err = PTR_ERR(i2s->clk);
+ goto err;
+ }
+
+ regmap_write(i2s->regmap, XTFPGA_I2S_CONFIG,
+ (0x1 << XTFPGA_I2S_CONFIG_CHANNEL_BASE));
+ regmap_write(i2s->regmap, XTFPGA_I2S_INT_STATUS, XTFPGA_I2S_INT_VALID);
+ regmap_write(i2s->regmap, XTFPGA_I2S_INT_MASK, XTFPGA_I2S_INT_UNDERRUN);
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0) {
+ dev_err(&pdev->dev, "No IRQ resource\n");
+ err = irq;
+ goto err;
+ }
+ err = devm_request_threaded_irq(&pdev->dev, irq, NULL,
+ xtfpga_i2s_threaded_irq_handler,
+ IRQF_SHARED | IRQF_ONESHOT,
+ pdev->name, i2s);
+ if (err < 0) {
+ dev_err(&pdev->dev, "request_irq failed\n");
+ goto err;
+ }
+
+ err = snd_soc_register_platform(&pdev->dev, &xtfpga_soc_platform);
+ if (err < 0) {
+ dev_err(&pdev->dev, "couldn't register platform\n");
+ goto err;
+ }
+ err = devm_snd_soc_register_component(&pdev->dev,
+ &xtfpga_i2s_component,
+ xtfpga_i2s_dai,
+ ARRAY_SIZE(xtfpga_i2s_dai));
+ if (err < 0) {
+ dev_err(&pdev->dev, "couldn't register component\n");
+ goto err_unregister_platform;
+ }
+
+ pm_runtime_enable(&pdev->dev);
+ if (!pm_runtime_enabled(&pdev->dev)) {
+ err = xtfpga_i2s_runtime_resume(&pdev->dev);
+ if (err)
+ goto err_pm_disable;
+ }
+ return 0;
+
+err_pm_disable:
+ pm_runtime_disable(&pdev->dev);
+err_unregister_platform:
+ snd_soc_unregister_platform(&pdev->dev);
+err:
+ dev_err(&pdev->dev, "%s: err = %d\n", __func__, err);
+ return err;
+}
+
+static int xtfpga_i2s_remove(struct platform_device *pdev)
+{
+ struct xtfpga_i2s *i2s = dev_get_drvdata(&pdev->dev);
+
+ snd_soc_unregister_platform(&pdev->dev);
+ if (i2s->regmap && !IS_ERR(i2s->regmap)) {
+ regmap_write(i2s->regmap, XTFPGA_I2S_CONFIG, 0);
+ regmap_write(i2s->regmap, XTFPGA_I2S_INT_MASK, 0);
+ regmap_write(i2s->regmap, XTFPGA_I2S_INT_STATUS,
+ XTFPGA_I2S_INT_VALID);
+ }
+ pm_runtime_disable(&pdev->dev);
+ if (!pm_runtime_status_suspended(&pdev->dev))
+ xtfpga_i2s_runtime_suspend(&pdev->dev);
+ return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id xtfpga_i2s_of_match[] = {
+ { .compatible = "cdns,xtfpga-i2s", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, xtfpga_i2s_of_match);
+#endif
+
+static const struct dev_pm_ops xtfpga_i2s_pm_ops = {
+ SET_RUNTIME_PM_OPS(xtfpga_i2s_runtime_suspend,
+ xtfpga_i2s_runtime_resume, NULL)
+};
+
+static struct platform_driver xtfpga_i2s_driver = {
+ .probe = xtfpga_i2s_probe,
+ .remove = xtfpga_i2s_remove,
+ .driver = {
+ .name = "xtfpga-i2s",
+ .of_match_table = of_match_ptr(xtfpga_i2s_of_match),
+ .pm = &xtfpga_i2s_pm_ops,
+ },
+};
+
+module_platform_driver(xtfpga_i2s_driver);
+
+MODULE_AUTHOR("Max Filippov <jcmvbkbc(a)gmail.com>");
+MODULE_DESCRIPTION("xtfpga I2S controller driver");
+MODULE_LICENSE("GPL v2");
--
1.8.1.4
