[PATCH v2 3/9] ASoC: uniphier: add support for UniPhier AIO DMA driver

[Katsuhiro Suzuki <suzuki.katsuhiro@socionext.com>]

This patch adds supports for UniPhier AIO DMA.

This module shared register area with all sound devices for
I2S, S/PDIF and so on. Since the AIO has mixed register map
for those I/Os, it is hard to split register areas for each
sound devices.

Signed-off-by: Katsuhiro Suzuki <suzuki.katsuhiro@socionext.com>

---

Changes in v2:
  - Change license comment style to C++ from C
  - Add error checks
  - Fix typo in error messages
  - Split DMA, CPU DAI patches from large one
  - Add comments to aiodma_irq()
  - Fix missing checks for return value
---
 sound/soc/uniphier/Makefile  |   2 +-
 sound/soc/uniphier/aio-dma.c | 317 +++++++++++++++++++++++++++++++++++++++++++
 sound/soc/uniphier/aio.h     |   2 +
 3 files changed, 320 insertions(+), 1 deletion(-)
 create mode 100644 sound/soc/uniphier/aio-dma.c

diff --git a/sound/soc/uniphier/Makefile b/sound/soc/uniphier/Makefile
index f3b36aba4879..9efe0feffdc2 100644
--- a/sound/soc/uniphier/Makefile
+++ b/sound/soc/uniphier/Makefile
@@ -1,5 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0
-snd-soc-uniphier-aio-cpu-objs := aio-core.o
+snd-soc-uniphier-aio-cpu-objs := aio-core.o aio-dma.o
 
 obj-$(CONFIG_SND_SOC_UNIPHIER_AIO) += snd-soc-uniphier-aio-cpu.o
 
diff --git a/sound/soc/uniphier/aio-dma.c b/sound/soc/uniphier/aio-dma.c
new file mode 100644
index 000000000000..6d0ca6dde913
--- /dev/null
+++ b/sound/soc/uniphier/aio-dma.c
@@ -0,0 +1,317 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Socionext UniPhier AIO DMA driver.
+//
+// Copyright (c) 2016-2018 Socionext Inc.
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License
+// as published by the Free Software Foundation; version 2
+// of the License.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, see <http://www.gnu.org/licenses/>.
+
+#include <linux/dma-mapping.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/soc.h>
+
+#include "aio.h"
+
+static struct snd_pcm_hardware uniphier_aiodma_hw = {
+	.info = SNDRV_PCM_INFO_MMAP |
+		SNDRV_PCM_INFO_MMAP_VALID |
+		SNDRV_PCM_INFO_INTERLEAVED,
+	.period_bytes_min = 256,
+	.period_bytes_max = 4096,
+	.periods_min      = 4,
+	.periods_max      = 1024,
+	.buffer_bytes_max = 128 * 1024,
+};
+
+static void aiodma_pcm_irq(struct uniphier_aio_sub *sub)
+{
+	struct snd_pcm_runtime *runtime = sub->substream->runtime;
+	int bytes = runtime->period_size *
+		runtime->channels * samples_to_bytes(runtime, 1);
+	int ret;
+
+	spin_lock(&sub->lock);
+	ret = aiodma_rb_set_threshold(sub, runtime->dma_bytes,
+				      sub->threshold + bytes);
+	if (!ret)
+		sub->threshold += bytes;
+
+	aiodma_rb_sync(sub, runtime->dma_addr, runtime->dma_bytes, bytes);
+	aiodma_rb_clear_irq(sub);
+	spin_unlock(&sub->lock);
+
+	snd_pcm_period_elapsed(sub->substream);
+}
+
+static void aiodma_compr_irq(struct uniphier_aio_sub *sub)
+{
+	struct snd_compr_runtime *runtime = sub->cstream->runtime;
+	int bytes = runtime->fragment_size;
+	int ret;
+
+	spin_lock(&sub->lock);
+	ret = aiodma_rb_set_threshold(sub, sub->compr_bytes,
+				      sub->threshold + bytes);
+	if (!ret)
+		sub->threshold += bytes;
+
+	aiodma_rb_sync(sub, sub->compr_addr, sub->compr_bytes, bytes);
+	aiodma_rb_clear_irq(sub);
+	spin_unlock(&sub->lock);
+
+	snd_compr_fragment_elapsed(sub->cstream);
+}
+
+static irqreturn_t aiodma_irq(int irq, void *p)
+{
+	struct platform_device *pdev = p;
+	struct uniphier_aio_chip *chip = platform_get_drvdata(pdev);
+	irqreturn_t ret = IRQ_NONE;
+	int i, j;
+
+	for (i = 0; i < chip->num_aios; i++) {
+		struct uniphier_aio *aio = &chip->aios[i];
+
+		for (j = 0; j < ARRAY_SIZE(aio->sub); j++) {
+			struct uniphier_aio_sub *sub = &aio->sub[j];
+
+			/* Skip channel that does not trigger */
+			if (!sub->running || !aiodma_rb_is_irq(sub))
+				continue;
+
+			if (sub->substream)
+				aiodma_pcm_irq(sub);
+			if (sub->cstream)
+				aiodma_compr_irq(sub);
+
+			ret = IRQ_HANDLED;
+		}
+	}
+
+	return ret;
+}
+
+static int uniphier_aiodma_open(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+
+	snd_soc_set_runtime_hwparams(substream, &uniphier_aiodma_hw);
+
+	return snd_pcm_hw_constraint_step(runtime, 0,
+		SNDRV_PCM_HW_PARAM_BUFFER_BYTES, 256);
+}
+
+static int uniphier_aiodma_hw_params(struct snd_pcm_substream *substream,
+				     struct snd_pcm_hw_params *params)
+{
+	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
+	substream->runtime->dma_bytes = params_buffer_bytes(params);
+
+	return 0;
+}
+
+static int uniphier_aiodma_hw_free(struct snd_pcm_substream *substream)
+{
+	snd_pcm_set_runtime_buffer(substream, NULL);
+	substream->runtime->dma_bytes = 0;
+
+	return 0;
+}
+
+static int uniphier_aiodma_prepare(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct snd_soc_pcm_runtime *rtd = snd_pcm_substream_chip(substream);
+	struct uniphier_aio *aio = uniphier_priv(rtd->cpu_dai);
+	struct uniphier_aio_sub *sub = &aio->sub[substream->stream];
+	int bytes = runtime->period_size *
+		runtime->channels * samples_to_bytes(runtime, 1);
+	unsigned long flags;
+	int ret;
+
+	ret = aiodma_ch_set_param(sub);
+	if (ret)
+		return ret;
+
+	spin_lock_irqsave(&sub->lock, flags);
+	ret = aiodma_rb_set_buffer(sub, runtime->dma_addr,
+				   runtime->dma_addr + runtime->dma_bytes,
+				   bytes);
+	spin_unlock_irqrestore(&sub->lock, flags);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static int uniphier_aiodma_trigger(struct snd_pcm_substream *substream, int cmd)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct snd_soc_pcm_runtime *rtd = snd_pcm_substream_chip(substream);
+	struct uniphier_aio *aio = uniphier_priv(rtd->cpu_dai);
+	struct uniphier_aio_sub *sub = &aio->sub[substream->stream];
+	struct device *dev = &aio->chip->pdev->dev;
+	int bytes = runtime->period_size *
+		runtime->channels * samples_to_bytes(runtime, 1);
+	unsigned long flags;
+
+	spin_lock_irqsave(&sub->lock, flags);
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+		aiodma_rb_sync(sub, runtime->dma_addr, runtime->dma_bytes,
+			       bytes);
+		aiodma_ch_set_enable(sub, 1);
+		sub->running = 1;
+
+		break;
+	case SNDRV_PCM_TRIGGER_STOP:
+		sub->running = 0;
+		aiodma_ch_set_enable(sub, 0);
+
+		break;
+	default:
+		dev_warn(dev, "Unknown trigger(%d) ignored\n", cmd);
+		break;
+	}
+	spin_unlock_irqrestore(&sub->lock, flags);
+
+	return 0;
+}
+
+static snd_pcm_uframes_t uniphier_aiodma_pointer(
+					struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct snd_soc_pcm_runtime *rtd = snd_pcm_substream_chip(substream);
+	struct uniphier_aio *aio = uniphier_priv(rtd->cpu_dai);
+	struct uniphier_aio_sub *sub = &aio->sub[substream->stream];
+	int bytes = runtime->period_size *
+		runtime->channels * samples_to_bytes(runtime, 1);
+	unsigned long flags;
+	snd_pcm_uframes_t pos;
+
+	spin_lock_irqsave(&sub->lock, flags);
+	aiodma_rb_sync(sub, runtime->dma_addr, runtime->dma_bytes, bytes);
+
+	if (sub->swm->dir == PORT_DIR_OUTPUT)
+		pos = bytes_to_frames(runtime, sub->rd_offs);
+	else
+		pos = bytes_to_frames(runtime, sub->wr_offs);
+	spin_unlock_irqrestore(&sub->lock, flags);
+
+	return pos;
+}
+
+static int uniphier_aiodma_mmap(struct snd_pcm_substream *substream,
+				struct vm_area_struct *vma)
+{
+	vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
+
+	return remap_pfn_range(vma, vma->vm_start,
+			       substream->dma_buffer.addr >> PAGE_SHIFT,
+			       vma->vm_end - vma->vm_start, vma->vm_page_prot);
+}
+
+static const struct snd_pcm_ops uniphier_aiodma_ops = {
+	.open      = uniphier_aiodma_open,
+	.ioctl     = snd_pcm_lib_ioctl,
+	.hw_params = uniphier_aiodma_hw_params,
+	.hw_free   = uniphier_aiodma_hw_free,
+	.prepare   = uniphier_aiodma_prepare,
+	.trigger   = uniphier_aiodma_trigger,
+	.pointer   = uniphier_aiodma_pointer,
+	.mmap      = uniphier_aiodma_mmap,
+};
+
+static int uniphier_aiodma_new(struct snd_soc_pcm_runtime *rtd)
+{
+	struct device *dev = rtd->card->snd_card->dev;
+	struct snd_pcm *pcm = rtd->pcm;
+	int ret;
+
+	ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(33));
+	if (ret)
+		return ret;
+
+	return snd_pcm_lib_preallocate_pages_for_all(pcm,
+		SNDRV_DMA_TYPE_DEV, dev,
+		uniphier_aiodma_hw.buffer_bytes_max,
+		uniphier_aiodma_hw.buffer_bytes_max);
+}
+
+static void uniphier_aiodma_free(struct snd_pcm *pcm)
+{
+	snd_pcm_lib_preallocate_free_for_all(pcm);
+}
+
+static const struct snd_soc_platform_driver uniphier_soc_platform = {
+	.pcm_new   = uniphier_aiodma_new,
+	.pcm_free  = uniphier_aiodma_free,
+	.ops       = &uniphier_aiodma_ops,
+};
+
+static const struct regmap_config aiodma_regmap_config = {
+	.reg_bits      = 32,
+	.reg_stride    = 4,
+	.val_bits      = 32,
+	.max_register  = 0x7fffc,
+	.cache_type    = REGCACHE_NONE,
+};
+
+/**
+ * uniphier_aiodma_soc_register_platform - register the AIO DMA
+ * @pdev: the platform device
+ *
+ * Register and setup the DMA of AIO to transfer the sound data to device.
+ * This function need to call once at driver startup and need NOT to call
+ * unregister function.
+ *
+ * Return: Zero if successful, otherwise a negative value on error.
+ */
+int uniphier_aiodma_soc_register_platform(struct platform_device *pdev)
+{
+	struct uniphier_aio_chip *chip = platform_get_drvdata(pdev);
+	struct device *dev = &pdev->dev;
+	struct resource *res;
+	void __iomem *preg;
+	int irq, ret;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	preg = devm_ioremap_resource(dev, res);
+	if (IS_ERR(preg))
+		return PTR_ERR(preg);
+
+	chip->regmap = devm_regmap_init_mmio(dev, preg,
+					     &aiodma_regmap_config);
+	if (IS_ERR(chip->regmap))
+		return PTR_ERR(chip->regmap);
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_err(dev, "Could not get irq.\n");
+		return irq;
+	}
+
+	ret = devm_request_irq(dev, irq, aiodma_irq,
+			       IRQF_SHARED, dev_name(dev), pdev);
+	if (ret)
+		return ret;
+
+	return devm_snd_soc_register_platform(dev, &uniphier_soc_platform);
+}
+EXPORT_SYMBOL_GPL(uniphier_aiodma_soc_register_platform);
diff --git a/sound/soc/uniphier/aio.h b/sound/soc/uniphier/aio.h
index 774abae28028..3687f6ff30b1 100644
--- a/sound/soc/uniphier/aio.h
+++ b/sound/soc/uniphier/aio.h
@@ -304,6 +304,8 @@ static inline struct uniphier_aio *uniphier_priv(struct snd_soc_dai *dai)
 	return &chip->aios[dai->id];
 }
 
+int uniphier_aiodma_soc_register_platform(struct platform_device *pdev);
+
 u64 aio_rb_cnt(struct uniphier_aio_sub *sub);
 u64 aio_rbt_cnt_to_end(struct uniphier_aio_sub *sub);
 u64 aio_rb_space(struct uniphier_aio_sub *sub);
-- 
2.15.0