--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+//
+// Xilinx ASoC SPDIF audio support
+//
+// Copyright (C) 2018 Xilinx, Inc.
+//
+// Author: Maruthi Srinivas Bayyavarapu <maruthis@xilinx.com>
+//
+
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+
+#define XLNX_SPDIF_RATES \
+ (SNDRV_PCM_RATE_32000 | SNDRV_PCM_RATE_44100 | SNDRV_PCM_RATE_48000 | \
+ SNDRV_PCM_RATE_88200 | SNDRV_PCM_RATE_96000 | SNDRV_PCM_RATE_176400 | \
+ SNDRV_PCM_RATE_192000)
+
+#define XLNX_SPDIF_FORMATS (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S24_LE)
+
+#define XSPDIF_IRQ_STS_REG 0x20
+#define XSPDIF_IRQ_ENABLE_REG 0x28
+#define XSPDIF_SOFT_RESET_REG 0x40
+#define XSPDIF_CONTROL_REG 0x44
+#define XSPDIF_CHAN_0_STS_REG 0x4C
+#define XSPDIF_GLOBAL_IRQ_ENABLE_REG 0x1C
+#define XSPDIF_CH_A_USER_DATA_REG_0 0x64
+
+#define XSPDIF_CORE_ENABLE_MASK BIT(0)
+#define XSPDIF_FIFO_FLUSH_MASK BIT(1)
+#define XSPDIF_CH_STS_MASK BIT(5)
+#define XSPDIF_GLOBAL_IRQ_ENABLE BIT(31)
+#define XSPDIF_CLOCK_CONFIG_BITS_MASK GENMASK(5, 2)
+#define XSPDIF_CLOCK_CONFIG_BITS_SHIFT 2
+#define XSPDIF_SOFT_RESET_VALUE 0xA
+
+#define MAX_CHANNELS 2
+#define AES_SAMPLE_WIDTH 32
+#define CH_STATUS_UPDATE_TIMEOUT 40
+
+struct spdif_dev_data {
+ u32 mode;
+ u32 aclk;
+ bool rx_chsts_updated;
+ void __iomem *base;
+ struct clk *axi_clk;
+ wait_queue_head_t chsts_q;
+};
+
+static irqreturn_t xlnx_spdifrx_irq_handler(int irq, void *arg)
+{
+ u32 val;
+ struct spdif_dev_data *ctx = arg;
+
+ val = readl(ctx->base + XSPDIF_IRQ_STS_REG);
+ if (val & XSPDIF_CH_STS_MASK) {
+ writel(val & XSPDIF_CH_STS_MASK,
+ ctx->base + XSPDIF_IRQ_STS_REG);
+ val = readl(ctx->base +
+ XSPDIF_IRQ_ENABLE_REG);
+ writel(val & ~XSPDIF_CH_STS_MASK,
+ ctx->base + XSPDIF_IRQ_ENABLE_REG);
+
+ ctx->rx_chsts_updated = true;
+ wake_up_interruptible(&ctx->chsts_q);
+ return IRQ_HANDLED;
+ }
+
+ return IRQ_NONE;
+}
+
+static int xlnx_spdif_startup(struct snd_pcm_substream *substream,
+ struct snd_soc_dai *dai)
+{
+ u32 val;
+ struct spdif_dev_data *ctx = dev_get_drvdata(dai->dev);
+
+ val = readl(ctx->base + XSPDIF_CONTROL_REG);
+ val |= XSPDIF_FIFO_FLUSH_MASK;
+ writel(val, ctx->base + XSPDIF_CONTROL_REG);
+
+ if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
+ writel(XSPDIF_CH_STS_MASK,
+ ctx->base + XSPDIF_IRQ_ENABLE_REG);
+ writel(XSPDIF_GLOBAL_IRQ_ENABLE,
+ ctx->base + XSPDIF_GLOBAL_IRQ_ENABLE_REG);
+ }
+
+ return 0;
+}
+
+static void xlnx_spdif_shutdown(struct snd_pcm_substream *substream,
+ struct snd_soc_dai *dai)
+{
+ struct spdif_dev_data *ctx = dev_get_drvdata(dai->dev);
+
+ writel(XSPDIF_SOFT_RESET_VALUE, ctx->base + XSPDIF_SOFT_RESET_REG);
+}
+
+static int xlnx_spdif_hw_params(struct snd_pcm_substream *substream,
+ struct snd_pcm_hw_params *params,
+ struct snd_soc_dai *dai)
+{
+ u32 val, clk_div, clk_cfg;
+ struct spdif_dev_data *ctx = dev_get_drvdata(dai->dev);
+
+ clk_div = DIV_ROUND_CLOSEST(ctx->aclk, MAX_CHANNELS * AES_SAMPLE_WIDTH *
+ params_rate(params));
+
+ switch (clk_div) {
+ case 4:
+ clk_cfg = 0;
+ break;
+ case 8:
+ clk_cfg = 1;
+ break;
+ case 16:
+ clk_cfg = 2;
+ break;
+ case 24:
+ clk_cfg = 3;
+ break;
+ case 32:
+ clk_cfg = 4;
+ break;
+ case 48:
+ clk_cfg = 5;
+ break;
+ case 64:
+ clk_cfg = 6;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ val = readl(ctx->base + XSPDIF_CONTROL_REG);
+ val &= ~XSPDIF_CLOCK_CONFIG_BITS_MASK;
+ val |= clk_cfg << XSPDIF_CLOCK_CONFIG_BITS_SHIFT;
+ writel(val, ctx->base + XSPDIF_CONTROL_REG);
+
+ return 0;
+}
+
+static int rx_stream_detect(struct snd_soc_dai *dai)
+{
+ int err;
+ struct spdif_dev_data *ctx = dev_get_drvdata(dai->dev);
+ unsigned long jiffies = msecs_to_jiffies(CH_STATUS_UPDATE_TIMEOUT);
+
+ /* start capture only if stream is detected within 40ms timeout */
+ err = wait_event_interruptible_timeout(ctx->chsts_q,
+ ctx->rx_chsts_updated,
+ jiffies);
+ if (!err) {
+ dev_err(dai->dev, "No streaming audio detected!\n");
+ return -EINVAL;
+ }
+ ctx->rx_chsts_updated = false;
+
+ return 0;
+}
+
+static int xlnx_spdif_trigger(struct snd_pcm_substream *substream, int cmd,
+ struct snd_soc_dai *dai)
+{
+ u32 val;
+ int ret = 0;
+ struct spdif_dev_data *ctx = dev_get_drvdata(dai->dev);
+
+ val = readl(ctx->base + XSPDIF_CONTROL_REG);
+ switch (cmd) {
+ case SNDRV_PCM_TRIGGER_START:
+ case SNDRV_PCM_TRIGGER_RESUME:
+ case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+ val |= XSPDIF_CORE_ENABLE_MASK;
+ writel(val, ctx->base + XSPDIF_CONTROL_REG);
+ if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
+ ret = rx_stream_detect(dai);
+ break;
+ case SNDRV_PCM_TRIGGER_STOP:
+ case SNDRV_PCM_TRIGGER_SUSPEND:
+ case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+ val &= ~XSPDIF_CORE_ENABLE_MASK;
+ writel(val, ctx->base + XSPDIF_CONTROL_REG);
+ break;
+ default:
+ ret = -EINVAL;
+ }
+
+ return ret;
+}
+
+static const struct snd_soc_dai_ops xlnx_spdif_dai_ops = {
+ .startup = xlnx_spdif_startup,
+ .shutdown = xlnx_spdif_shutdown,
+ .trigger = xlnx_spdif_trigger,
+ .hw_params = xlnx_spdif_hw_params,
+};
+
+static struct snd_soc_dai_driver xlnx_spdif_tx_dai = {
+ .name = "xlnx_spdif_tx",
+ .playback = {
+ .channels_min = 2,
+ .channels_max = 2,
+ .rates = XLNX_SPDIF_RATES,
+ .formats = XLNX_SPDIF_FORMATS,
+ },
+ .ops = &xlnx_spdif_dai_ops,
+};
+
+static struct snd_soc_dai_driver xlnx_spdif_rx_dai = {
+ .name = "xlnx_spdif_rx",
+ .capture = {
+ .channels_min = 2,
+ .channels_max = 2,
+ .rates = XLNX_SPDIF_RATES,
+ .formats = XLNX_SPDIF_FORMATS,
+ },
+ .ops = &xlnx_spdif_dai_ops,
+};
+
+static const struct snd_soc_component_driver xlnx_spdif_component = {
+ .name = "xlnx-spdif",
+};
+
+static const struct of_device_id xlnx_spdif_of_match[] = {
+ { .compatible = "xlnx,spdif-2.0", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, xlnx_spdif_of_match);
+
+static int xlnx_spdif_probe(struct platform_device *pdev)
+{
+ int ret;
+ struct resource *res;
+ struct snd_soc_dai_driver *dai_drv;
+ struct spdif_dev_data *ctx;
+
+ struct device *dev = &pdev->dev;
+ struct device_node *node = dev->of_node;
+
+ ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
+ if (!ctx)
+ return -ENOMEM;
+
+ ctx->axi_clk = devm_clk_get(dev, "s_axi_aclk");
+ if (IS_ERR(ctx->axi_clk)) {
+ ret = PTR_ERR(ctx->axi_clk);
+ dev_err(dev, "failed to get s_axi_aclk(%d)\n", ret);
+ return ret;
+ }
+ ret = clk_prepare_enable(ctx->axi_clk);
+ if (ret) {
+ dev_err(dev, "failed to enable s_axi_aclk(%d)\n", ret);
+ return ret;
+ }
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ ctx->base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(ctx->base)) {
+ ret = PTR_ERR(ctx->base);
+ goto clk_err;
+ }
+ ret = of_property_read_u32(node, "xlnx,spdif-mode", &ctx->mode);
+ if (ret < 0) {
+ dev_err(dev, "cannot get SPDIF mode\n");
+ goto clk_err;
+ }
+ if (ctx->mode) {
+ dai_drv = &xlnx_spdif_tx_dai;
+ } else {
+ res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+ if (!res) {
+ dev_err(dev, "No IRQ resource found\n");
+ ret = -ENODEV;
+ goto clk_err;
+ }
+ ret = devm_request_irq(dev, res->start,
+ xlnx_spdifrx_irq_handler,
+ 0, "XLNX_SPDIF_RX", ctx);
+ if (ret) {
+ dev_err(dev, "spdif rx irq request failed\n");
+ ret = -ENODEV;
+ goto clk_err;
+ }
+
+ init_waitqueue_head(&ctx->chsts_q);
+ dai_drv = &xlnx_spdif_rx_dai;
+ }
+
+ ret = of_property_read_u32(node, "xlnx,aud_clk_i", &ctx->aclk);
+ if (ret < 0) {
+ dev_err(dev, "cannot get aud_clk_i value\n");
+ goto clk_err;
+ }
+
+ dev_set_drvdata(dev, ctx);
+
+ ret = devm_snd_soc_register_component(dev, &xlnx_spdif_component,
+ dai_drv, 1);
+ if (ret) {
+ dev_err(dev, "SPDIF component registration failed\n");
+ goto clk_err;
+ }
+
+ writel(XSPDIF_SOFT_RESET_VALUE, ctx->base + XSPDIF_SOFT_RESET_REG);
+ dev_info(dev, "%s DAI registered\n", dai_drv->name);
+
+clk_err:
+ clk_disable_unprepare(ctx->axi_clk);
+ return ret;
+}
+
+static int xlnx_spdif_remove(struct platform_device *pdev)
+{
+ struct spdif_dev_data *ctx = dev_get_drvdata(&pdev->dev);
+
+ clk_disable_unprepare(ctx->axi_clk);
+ return 0;
+}
+
+static struct platform_driver xlnx_spdif_driver = {
+ .driver = {
+ .name = "xlnx-spdif",
+ .of_match_table = xlnx_spdif_of_match,
+ },
+ .probe = xlnx_spdif_probe,
+ .remove = xlnx_spdif_remove,
+};
+module_platform_driver(xlnx_spdif_driver);
+
+MODULE_AUTHOR("Maruthi Srinivas Bayyavarapu <maruthis@xilinx.com>");
+MODULE_DESCRIPTION("XILINX SPDIF driver");
+MODULE_LICENSE("GPL v2");
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