[RFC 22/37] ASoC: Intel: avs: Implement CLDMA transfer

[Cezary Rojewski <cezary.rojewski@intel.com>]

SKL and KBL rely on a dedicated HDAudio DMA stream for code loading and
authentication. The implementation of this specific mechanism for
SKL-based platforms re-uses HDAudio DMA (streaming) functions found in
HDA library to avoid duplication of functionality.

Signed-off-by: Amadeusz Sławiński <amadeuszx.slawinski@linux.intel.com>
Signed-off-by: Cezary Rojewski <cezary.rojewski@intel.com>
---
 sound/soc/intel/avs/Makefile    |   1 +
 sound/soc/intel/avs/cldma.c     | 328 ++++++++++++++++++++++++++++++++
 sound/soc/intel/avs/cldma.h     |  29 +++
 sound/soc/intel/avs/registers.h |   2 +
 4 files changed, 360 insertions(+)
 create mode 100644 sound/soc/intel/avs/cldma.c
 create mode 100644 sound/soc/intel/avs/cldma.h

diff --git a/sound/soc/intel/avs/Makefile b/sound/soc/intel/avs/Makefile
index 31a51b08774d..53b14d901e2f 100644
--- a/sound/soc/intel/avs/Makefile
+++ b/sound/soc/intel/avs/Makefile
@@ -2,5 +2,6 @@
 
 snd-soc-avs-objs := dsp.o ipc.o messages.o utils.o topology.o path.o \
 		    core.o loader.o
+snd-soc-avs-objs += cldma.o
 
 obj-$(CONFIG_SND_SOC_INTEL_AVS) += snd-soc-avs.o
diff --git a/sound/soc/intel/avs/cldma.c b/sound/soc/intel/avs/cldma.c
new file mode 100644
index 000000000000..1ec2250e5323
--- /dev/null
+++ b/sound/soc/intel/avs/cldma.c
@@ -0,0 +1,328 @@
+// SPDX-License-Identifier: GPL-2.0-only
+//
+// Copyright(c) 2021 Intel Corporation. All rights reserved.
+//
+// Author: Cezary Rojewski <cezary.rojewski@intel.com>
+//
+
+#include <linux/pci.h>
+#include <sound/hda_register.h>
+#include <sound/hdaudio_ext.h>
+#include "cldma.h"
+#include "registers.h"
+
+/* Stream Registers */
+#define AZX_CL_SD_BASE			0x80
+#define AZX_SD_CTL_STRM_MASK		GENMASK(23, 20)
+#define AZX_SD_CTL_STRM(s) \
+	(((s)->stream_tag << 20) & AZX_SD_CTL_STRM_MASK)
+#define AZX_SD_BDLPL_BDLPLBA_MASK	GENMASK(31, 7)
+#define AZX_SD_BDLPL_BDLPLBA(lb)	((lb) & AZX_SD_BDLPL_BDLPLBA_MASK)
+
+/* Software Position Based FIFO Capability Registers */
+#define AZX_CL_SPBFCS			0x20
+#define AZX_REG_CL_SPBFCTL		(AZX_CL_SPBFCS + 0x4)
+#define AZX_REG_CL_SD_SPIB		(AZX_CL_SPBFCS + 0x8)
+
+#define AVS_CL_OP_INTERVAL_US		3
+#define AVS_CL_OP_TIMEOUT_US		300
+#define AVS_CL_IOC_TIMEOUT_MS		300
+#define AVS_CL_STREAM_INDEX		0
+
+struct hda_cldma {
+	struct device *dev;
+	struct hdac_bus *bus;
+	void __iomem *adsp_ba;
+
+	unsigned int buffer_size;
+	unsigned int num_periods;
+	unsigned int stream_tag;
+	void __iomem *sd_addr;
+
+	struct snd_dma_buffer dmab_data;
+	struct snd_dma_buffer dmab_bdl;
+	struct delayed_work memcpy_work;
+	struct completion completion;
+
+	/* runtime */
+	void *position;
+	unsigned int remaining;
+	unsigned int sd_status;
+};
+
+static void cldma_memcpy_work(struct work_struct *work);
+
+struct hda_cldma code_loader = {
+	.stream_tag	= AVS_CL_STREAM_INDEX + 1,
+	.memcpy_work	= __DELAYED_WORK_INITIALIZER(code_loader.memcpy_work,
+						     cldma_memcpy_work, 0),
+	.completion	= COMPLETION_INITIALIZER(code_loader.completion),
+};
+
+void hda_cldma_fill(struct hda_cldma *cl)
+{
+	unsigned int size, offset;
+
+	if (cl->remaining > cl->buffer_size)
+		size = cl->buffer_size;
+	else
+		size = cl->remaining;
+
+	offset = snd_hdac_stream_readl(cl, CL_SD_SPIB);
+	if (offset + size > cl->buffer_size) {
+		unsigned int ss;
+
+		ss = cl->buffer_size - offset;
+		memcpy(cl->dmab_data.area + offset, cl->position, ss);
+		offset = 0;
+		size -= ss;
+		cl->position += ss;
+		cl->remaining -= ss;
+	}
+
+	memcpy(cl->dmab_data.area + offset, cl->position, size);
+	cl->position += size;
+	cl->remaining -= size;
+
+	snd_hdac_stream_writel(cl, CL_SD_SPIB, offset + size);
+}
+
+static void cldma_memcpy_work(struct work_struct *work)
+{
+	struct hda_cldma *cl =
+		container_of(work, struct hda_cldma, memcpy_work.work);
+	int ret;
+
+	ret = hda_cldma_start(cl);
+	if (ret < 0) {
+		dev_err(cl->dev, "cldma set RUN failed: %d\n", ret);
+		return;
+	}
+
+	while (true) {
+		ret = wait_for_completion_timeout(&cl->completion,
+				msecs_to_jiffies(AVS_CL_IOC_TIMEOUT_MS));
+		if (!ret) {
+			dev_err(cl->dev, "cldma IOC timeout\n");
+			break;
+		}
+
+		if (!(cl->sd_status & SD_INT_COMPLETE)) {
+			dev_err(cl->dev, "cldma transfer error, SD status: 0x%08x\n",
+				cl->sd_status);
+			break;
+		}
+
+		if (!cl->remaining)
+			break;
+
+		reinit_completion(&cl->completion);
+		hda_cldma_fill(cl);
+		/* enable CLDMA interrupt */
+		snd_hdac_adsp_updatel(cl, AVS_ADSP_REG_ADSPIC,
+				      AVS_ADSP_ADSPIC_CLDMA,
+				      AVS_ADSP_ADSPIC_CLDMA);
+	}
+}
+
+void hda_cldma_transfer(struct hda_cldma *cl, unsigned long start_delay)
+{
+	if (!cl->remaining)
+		return;
+
+	reinit_completion(&cl->completion);
+	/* fill buffer with the first chunk before scheduling run */
+	hda_cldma_fill(cl);
+
+	schedule_delayed_work(&cl->memcpy_work, start_delay);
+}
+
+int hda_cldma_start(struct hda_cldma *cl)
+{
+	unsigned int reg;
+
+	/* enable interrupts */
+	snd_hdac_adsp_updatel(cl, AVS_ADSP_REG_ADSPIC,
+			      AVS_ADSP_ADSPIC_CLDMA, AVS_ADSP_ADSPIC_CLDMA);
+	snd_hdac_stream_updateb(cl, SD_CTL, SD_INT_MASK | SD_CTL_DMA_START,
+				SD_INT_MASK | SD_CTL_DMA_START);
+
+	/* await DMA engine start */
+	return snd_hdac_stream_readb_poll(cl, SD_CTL, reg,
+					  (reg & SD_CTL_DMA_START),
+					  AVS_CL_OP_INTERVAL_US, AVS_CL_OP_TIMEOUT_US);
+}
+
+int hda_cldma_stop(struct hda_cldma *cl)
+{
+	unsigned int reg;
+	int ret;
+
+	/* disable interrupts */
+	snd_hdac_adsp_updatel(cl, AVS_ADSP_REG_ADSPIC,
+			      AVS_ADSP_ADSPIC_CLDMA, 0);
+	snd_hdac_stream_updateb(cl, SD_CTL, SD_INT_MASK | SD_CTL_DMA_START, 0);
+
+	/* await DMA engine stop */
+	ret = snd_hdac_stream_readb_poll(cl, SD_CTL, reg,
+					 !(reg & SD_CTL_DMA_START),
+					  AVS_CL_OP_INTERVAL_US, AVS_CL_OP_TIMEOUT_US);
+	cancel_delayed_work_sync(&cl->memcpy_work);
+
+	return ret;
+}
+
+int hda_cldma_reset(struct hda_cldma *cl)
+{
+	unsigned int reg;
+	int ret;
+
+	ret = hda_cldma_stop(cl);
+	if (ret < 0) {
+		dev_err(cl->dev, "cldma stop failed: %d\n", ret);
+		return ret;
+	}
+
+	snd_hdac_stream_updateb(cl, SD_CTL, 1, 1);
+	ret = snd_hdac_stream_readb_poll(cl, SD_CTL, reg, (reg & 1),
+					 AVS_CL_OP_INTERVAL_US, AVS_CL_OP_TIMEOUT_US);
+	if (ret < 0) {
+		dev_err(cl->dev, "cldma set SRST failed: %d\n", ret);
+		return ret;
+	}
+
+	snd_hdac_stream_updateb(cl, SD_CTL, 1, 0);
+	ret = snd_hdac_stream_readb_poll(cl, SD_CTL, reg, !(reg & 1),
+					 AVS_CL_OP_INTERVAL_US, AVS_CL_OP_TIMEOUT_US);
+	if (ret < 0) {
+		dev_err(cl->dev, "cldma unset SRST failed: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+void hda_cldma_set_data(struct hda_cldma *cl, void *data, unsigned int size)
+{
+	/* setup runtime */
+	cl->position = data;
+	cl->remaining = size;
+}
+
+static void cldma_setup_bdle(struct hda_cldma *cl, u32 bdle_size)
+{
+	struct snd_dma_buffer *dmab = &cl->dmab_data;
+	__le32 *bdl = (__le32 *)cl->dmab_bdl.area;
+	int remaining = cl->buffer_size;
+	int offset = 0;
+
+	cl->num_periods = 0;
+
+	while (remaining > 0) {
+		phys_addr_t addr;
+		int chunk;
+
+		addr = snd_sgbuf_get_addr(dmab, offset);
+		bdl[0] = cpu_to_le32(lower_32_bits(addr));
+		bdl[1] = cpu_to_le32(upper_32_bits(addr));
+		chunk = snd_sgbuf_get_chunk_size(dmab, offset, bdle_size);
+		bdl[2] = cpu_to_le32(chunk);
+
+		remaining -= chunk;
+		/* set IOC only for the last entry */
+		bdl[3] = (remaining > 0) ? 0 : cpu_to_le32(0x01);
+
+		bdl += 4;
+		offset += chunk;
+		cl->num_periods++;
+	}
+}
+
+void hda_cldma_setup(struct hda_cldma *cl)
+{
+	dma_addr_t bdl_addr = cl->dmab_bdl.addr;
+
+	cldma_setup_bdle(cl, cl->buffer_size / 2);
+
+	snd_hdac_stream_writel(cl, SD_BDLPL,
+			       AZX_SD_BDLPL_BDLPLBA(lower_32_bits(bdl_addr)));
+	snd_hdac_stream_writel(cl, SD_BDLPU, upper_32_bits(bdl_addr));
+
+	snd_hdac_stream_writel(cl, SD_CBL, cl->buffer_size);
+	snd_hdac_stream_writeb(cl, SD_LVI, cl->num_periods - 1);
+
+	snd_hdac_stream_updatel(cl, SD_CTL,
+				AZX_SD_CTL_STRM_MASK, AZX_SD_CTL_STRM(cl));
+	/* enable spib */
+	snd_hdac_stream_writel(cl, CL_SPBFCTL, 1);
+}
+
+static irqreturn_t cldma_irq_handler(int irq, void *dev_id)
+{
+	struct hda_cldma *cl = dev_id;
+	u32 adspis;
+
+	adspis = snd_hdac_adsp_readl(cl, AVS_ADSP_REG_ADSPIS);
+	if (adspis == UINT_MAX)
+		return IRQ_NONE;
+	if (!(adspis & AVS_ADSP_ADSPIS_CLDMA))
+		return IRQ_NONE;
+
+	cl->sd_status = snd_hdac_stream_readb(cl, SD_STS);
+	dev_warn(cl->dev, "%s sd_status: 0x%08x\n", __func__, cl->sd_status);
+
+	/* disable CLDMA interrupt */
+	snd_hdac_adsp_updatel(cl, AVS_ADSP_REG_ADSPIC,
+			      AVS_ADSP_ADSPIC_CLDMA, 0);
+
+	complete(&cl->completion);
+
+	return IRQ_HANDLED;
+}
+
+int hda_cldma_init(struct hda_cldma *cl, struct hdac_bus *bus,
+		    void __iomem *adsp_ba, unsigned int buffer_size)
+{
+	struct pci_dev *pci = to_pci_dev(bus->dev);
+	int ret;
+
+	ret = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV_SG, bus->dev,
+				  buffer_size, &cl->dmab_data);
+	if (ret < 0)
+		return ret;
+
+	ret = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, bus->dev,
+				  BDL_SIZE, &cl->dmab_bdl);
+	if (ret < 0)
+		goto alloc_err;
+
+	cl->dev = bus->dev;
+	cl->bus = bus;
+	cl->adsp_ba = adsp_ba;
+	cl->buffer_size = buffer_size;
+	cl->sd_addr = adsp_ba + AZX_CL_SD_BASE;
+
+	ret = pci_request_irq(pci, 0, cldma_irq_handler, NULL, cl, "CLDMA");
+	if (ret < 0) {
+		dev_err(cl->dev, "Failed to request CLDMA IRQ handler: %d\n", ret);
+		goto req_err;
+	}
+
+	return 0;
+
+req_err:
+	snd_dma_free_pages(&cl->dmab_bdl);
+alloc_err:
+	snd_dma_free_pages(&cl->dmab_data);
+
+	return ret;
+}
+
+void hda_cldma_free(struct hda_cldma *cl)
+{
+	struct pci_dev *pci = to_pci_dev(cl->dev);
+
+	pci_free_irq(pci, 0, cl);
+	snd_dma_free_pages(&cl->dmab_data);
+	snd_dma_free_pages(&cl->dmab_bdl);
+}
diff --git a/sound/soc/intel/avs/cldma.h b/sound/soc/intel/avs/cldma.h
new file mode 100644
index 000000000000..d99a57061a43
--- /dev/null
+++ b/sound/soc/intel/avs/cldma.h
@@ -0,0 +1,29 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright(c) 2021 Intel Corporation. All rights reserved.
+ *
+ * Author: Cezary Rojewski <cezary.rojewski@intel.com>
+ */
+
+#ifndef __SOUND_SOC_INTEL_AVS_CLDMA_H
+#define __SOUND_SOC_INTEL_AVS_CLDMA_H
+
+#define AVS_CL_DEFAULT_BUFFER_SIZE	(32 * PAGE_SIZE)
+
+struct hda_cldma;
+extern struct hda_cldma code_loader;
+
+void hda_cldma_fill(struct hda_cldma *cl);
+void hda_cldma_transfer(struct hda_cldma *cl, unsigned long start_delay);
+
+int hda_cldma_start(struct hda_cldma *cl);
+int hda_cldma_stop(struct hda_cldma *cl);
+int hda_cldma_reset(struct hda_cldma *cl);
+
+void hda_cldma_set_data(struct hda_cldma *cl, void *data, unsigned int size);
+void hda_cldma_setup(struct hda_cldma *cl);
+int hda_cldma_init(struct hda_cldma *cl, struct hdac_bus *bus,
+		    void __iomem *adsp_ba, unsigned int buffer_size);
+void hda_cldma_free(struct hda_cldma *cl);
+
+#endif
diff --git a/sound/soc/intel/avs/registers.h b/sound/soc/intel/avs/registers.h
index 4caa95aa3846..d607edd877d8 100644
--- a/sound/soc/intel/avs/registers.h
+++ b/sound/soc/intel/avs/registers.h
@@ -22,7 +22,9 @@
 #define AVS_ADSP_REG_ADSPIS		(AVS_ADSP_GEN_BASE + 0x0C)
 
 #define AVS_ADSP_ADSPIC_IPC		BIT(0)
+#define AVS_ADSP_ADSPIC_CLDMA		BIT(1)
 #define AVS_ADSP_ADSPIS_IPC		BIT(0)
+#define AVS_ADSP_ADSPIS_CLDMA		BIT(1)
 
 #define AVS_ADSPCS_CRST_MASK(cm)	(cm)
 #define AVS_ADSPCS_CSTALL_MASK(cm)	((cm) << 8)
-- 
2.25.1