ASoC: loongson: Add I2S controller driver as platform device

The Loongson I2S controller exists not only in PCI form (LS7A bridge
chip), but also in platform device form (Loongson-2K1000 SoC).

This patch adds support for platform device I2S controller.

Signed-off-by: Binbin Zhou <zhoubinbin@loongson.cn>
Link: https://patch.msgid.link/36c143358c7f48bc2e73c30e1d2009b2f2fc6498.1728459624.git.zhoubinbin@loongson.cn
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/loongson/Kconfig

@@ -1,27 +1,38 @@
 # SPDX-License-Identifier: GPL-2.0
 menu "SoC Audio for Loongson CPUs"
+
+config SND_SOC_LOONGSON_CARD
+	tristate "Loongson Sound Card Driver"
 	depends on LOONGARCH || COMPILE_TEST
+	select SND_SOC_LOONGSON_I2S_PCI if PCI
+	select SND_SOC_LOONGSON_I2S_PLATFORM if OF
+	help
+	  Say Y or M if you want to add support for SoC audio using
+	  loongson I2S controller.
+
+	  The driver add support for ALSA SoC Audio support using
+	  loongson I2S controller.
 
 config SND_SOC_LOONGSON_I2S_PCI
 	tristate "Loongson I2S-PCI Device Driver"
+	depends on LOONGARCH || COMPILE_TEST
 	select REGMAP_MMIO
-	depends on PCI
 	help
 	  Say Y or M if you want to add support for I2S driver for
 	  Loongson I2S controller.
 
 	  The controller is found in loongson bridge chips or SoCs,
 	  and work as a PCI device.
 
-config SND_SOC_LOONGSON_CARD
-	tristate "Loongson Sound Card Driver"
-	select SND_SOC_LOONGSON_I2S_PCI
-	depends on PCI
+config SND_SOC_LOONGSON_I2S_PLATFORM
+	tristate "Loongson I2S-PLAT Device Driver"
+	depends on LOONGARCH || COMPILE_TEST
+	select REGMAP_MMIO
+	select SND_SOC_GENERIC_DMAENGINE_PCM
 	help
-	  Say Y or M if you want to add support for SoC audio using
-	  loongson I2S controller.
-
-	  The driver add support for ALSA SoC Audio support using
-	  loongson I2S controller.
+	  Say Y or M if you want to add support for I2S driver for
+	  Loongson I2S controller.
 
+	  The controller work as a platform device, we can found it in
+	  Loongson-2K1000 SoCs.
 endmenu

sound/soc/loongson/Makefile

@@ -3,6 +3,9 @@
 snd-soc-loongson-i2s-pci-y := loongson_i2s_pci.o loongson_i2s.o loongson_dma.o
 obj-$(CONFIG_SND_SOC_LOONGSON_I2S_PCI) += snd-soc-loongson-i2s-pci.o
 
+snd-soc-loongson-i2s-plat-y := loongson_i2s_plat.o loongson_i2s.o
+obj-$(CONFIG_SND_SOC_LOONGSON_I2S_PLATFORM) += snd-soc-loongson-i2s-plat.o
+
 #Machine Support
 snd-soc-loongson-card-y := loongson_card.o
 obj-$(CONFIG_SND_SOC_LOONGSON_CARD) += snd-soc-loongson-card.o

sound/soc/loongson/loongson_i2s_plat.c

@@ -0,0 +1,185 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Loongson I2S controller master mode dirver(platform device)
+//
+// Copyright (C) 2023-2024 Loongson Technology Corporation Limited
+//
+// Author: Yingkun Meng <mengyingkun@loongson.cn>
+//         Binbin Zhou <zhoubinbin@loongson.cn>
+
+#include <linux/clk.h>
+#include <linux/dma-mapping.h>
+#include <linux/module.h>
+#include <linux/of_dma.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <sound/dmaengine_pcm.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+
+#include "loongson_i2s.h"
+
+#define LOONGSON_I2S_RX_DMA_OFFSET	21
+#define LOONGSON_I2S_TX_DMA_OFFSET	18
+
+#define LOONGSON_DMA0_CONF	0x0
+#define LOONGSON_DMA1_CONF	0x1
+#define LOONGSON_DMA2_CONF	0x2
+#define LOONGSON_DMA3_CONF	0x3
+#define LOONGSON_DMA4_CONF	0x4
+
+/* periods_max = PAGE_SIZE / sizeof(struct ls_dma_chan_reg) */
+static const struct snd_pcm_hardware loongson_pcm_hardware = {
+	.info = SNDRV_PCM_INFO_MMAP |
+		SNDRV_PCM_INFO_INTERLEAVED |
+		SNDRV_PCM_INFO_MMAP_VALID |
+		SNDRV_PCM_INFO_RESUME |
+		SNDRV_PCM_INFO_PAUSE,
+	.formats = SNDRV_PCM_FMTBIT_S16_LE |
+		   SNDRV_PCM_FMTBIT_S20_3LE |
+		   SNDRV_PCM_FMTBIT_S24_LE,
+	.period_bytes_min = 128,
+	.period_bytes_max = 128 * 1024,
+	.periods_min = 1,
+	.periods_max = 64,
+	.buffer_bytes_max = 1024 * 1024,
+};
+
+static const struct snd_dmaengine_pcm_config loongson_dmaengine_pcm_config = {
+	.pcm_hardware = &loongson_pcm_hardware,
+	.prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config,
+	.prealloc_buffer_size = 128 * 1024,
+};
+
+static int loongson_pcm_open(struct snd_soc_component *component,
+			     struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+
+	if (substream->pcm->device & 1) {
+		runtime->hw.info &= ~SNDRV_PCM_INFO_INTERLEAVED;
+		runtime->hw.info |= SNDRV_PCM_INFO_NONINTERLEAVED;
+	}
+
+	if (substream->pcm->device & 2)
+		runtime->hw.info &= ~(SNDRV_PCM_INFO_MMAP |
+				      SNDRV_PCM_INFO_MMAP_VALID);
+	/*
+	 * For mysterious reasons (and despite what the manual says)
+	 * playback samples are lost if the DMA count is not a multiple
+	 * of the DMA burst size.  Let's add a rule to enforce that.
+	 */
+	snd_pcm_hw_constraint_step(runtime, 0,
+				   SNDRV_PCM_HW_PARAM_PERIOD_BYTES, 128);
+	snd_pcm_hw_constraint_step(runtime, 0,
+				   SNDRV_PCM_HW_PARAM_BUFFER_BYTES, 128);
+	snd_pcm_hw_constraint_integer(substream->runtime,
+				      SNDRV_PCM_HW_PARAM_PERIODS);
+
+	return 0;
+}
+
+static const struct snd_soc_component_driver loongson_i2s_component_driver = {
+	.name   = LS_I2S_DRVNAME,
+	.open	= loongson_pcm_open,
+};
+
+static const struct regmap_config loongson_i2s_regmap_config = {
+	.reg_bits = 32,
+	.reg_stride = 4,
+	.val_bits = 32,
+	.max_register = 0x14,
+	.cache_type = REGCACHE_FLAT,
+};
+
+static int loongson_i2s_apbdma_config(struct platform_device *pdev)
+{
+	int val;
+	void __iomem *regs;
+
+	regs = devm_platform_ioremap_resource(pdev, 1);
+	if (IS_ERR(regs))
+		return PTR_ERR(regs);
+
+	val = readl(regs);
+	val |= LOONGSON_DMA2_CONF << LOONGSON_I2S_TX_DMA_OFFSET;
+	val |= LOONGSON_DMA3_CONF << LOONGSON_I2S_RX_DMA_OFFSET;
+	writel(val, regs);
+
+	return 0;
+}
+
+static int loongson_i2s_plat_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct loongson_i2s *i2s;
+	struct resource *res;
+	struct clk *i2s_clk;
+	int ret;
+
+	i2s = devm_kzalloc(dev, sizeof(*i2s), GFP_KERNEL);
+	if (!i2s)
+		return -ENOMEM;
+
+	ret = loongson_i2s_apbdma_config(pdev);
+	if (ret)
+		return ret;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	i2s->reg_base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(i2s->reg_base))
+		return dev_err_probe(dev, PTR_ERR(i2s->reg_base),
+				     "devm_ioremap_resource failed\n");
+
+	i2s->regmap = devm_regmap_init_mmio(dev, i2s->reg_base,
+					    &loongson_i2s_regmap_config);
+	if (IS_ERR(i2s->regmap))
+		return dev_err_probe(dev, PTR_ERR(i2s->regmap),
+				     "devm_regmap_init_mmio failed\n");
+
+	i2s->playback_dma_data.addr = res->start + LS_I2S_TX_DATA;
+	i2s->playback_dma_data.addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+	i2s->playback_dma_data.maxburst = 4;
+
+	i2s->capture_dma_data.addr = res->start + LS_I2S_RX_DATA;
+	i2s->capture_dma_data.addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+	i2s->capture_dma_data.maxburst = 4;
+
+	i2s_clk = devm_clk_get_enabled(dev, NULL);
+	if (IS_ERR(i2s_clk))
+		return dev_err_probe(dev, PTR_ERR(i2s_clk), "clock property invalid\n");
+	i2s->clk_rate = clk_get_rate(i2s_clk);
+
+	dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64));
+	dev_set_name(dev, LS_I2S_DRVNAME);
+	dev_set_drvdata(dev, i2s);
+
+	ret = devm_snd_soc_register_component(dev, &loongson_i2s_component_driver,
+					      &loongson_i2s_dai, 1);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to register DAI\n");
+
+	return devm_snd_dmaengine_pcm_register(dev, &loongson_dmaengine_pcm_config,
+					       SND_DMAENGINE_PCM_FLAG_COMPAT);
+}
+
+static const struct of_device_id loongson_i2s_ids[] = {
+	{ .compatible = "loongson,ls2k1000-i2s" },
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, loongson_i2s_ids);
+
+static struct platform_driver loongson_i2s_driver = {
+	.probe = loongson_i2s_plat_probe,
+	.driver = {
+		.name = "loongson-i2s-plat",
+		.pm = pm_sleep_ptr(&loongson_i2s_pm),
+		.of_match_table = loongson_i2s_ids,
+	},
+};
+module_platform_driver(loongson_i2s_driver);
+
+MODULE_DESCRIPTION("Loongson I2S Master Mode ASoC Driver");
+MODULE_AUTHOR("Loongson Technology Corporation Limited");
+MODULE_LICENSE("GPL");