ASoC: qcom: Add Storm machine driver

Add machine driver for the Storm board with the
IPQ806X SOC connected to the MAX98357A DAC.
Signed-off-by: Kenneth Westfield <kwestfie@codeaurora.org>
Acked-by: Banajit Goswami <bgoswami@codeaurora.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/qcom/storm.c

+/*
+ * Copyright (c) 2010-2011,2013-2015 The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * 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.
+ *
+ * storm.c -- ALSA SoC machine driver for QTi ipq806x-based Storm board
+ */
+
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/mod_devicetable.h>
+#include <linux/platform_device.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+
+#define STORM_SYSCLK_MULT			4
+
+static int storm_ops_hw_params(struct snd_pcm_substream *substream,
+		struct snd_pcm_hw_params *params)
+{
+	struct snd_soc_pcm_runtime *soc_runtime = substream->private_data;
+	struct snd_soc_card *card = soc_runtime->card;
+	snd_pcm_format_t format = params_format(params);
+	unsigned int rate = params_rate(params);
+	unsigned int sysclk_freq;
+	int bitwidth, ret;
+
+	bitwidth = snd_pcm_format_width(format);
+	if (bitwidth < 0) {
+		dev_err(card->dev, "%s() invalid bit width given: %d\n",
+				__func__, bitwidth);
+		return bitwidth;
+	}
+
+	/*
+	 * as the CPU DAI is the I2S bus master and no system clock is needed by
+	 * the MAX98357a DAC, simply set the system clock to be a constant
+	 * multiple of the bit clock for the clock divider
+	 */
+	sysclk_freq = rate * bitwidth * 2 * STORM_SYSCLK_MULT;
+
+	ret = snd_soc_dai_set_sysclk(soc_runtime->cpu_dai, 0, sysclk_freq, 0);
+	if (ret) {
+		dev_err(card->dev, "%s() error setting sysclk to %u: %d\n",
+				__func__, sysclk_freq, ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static struct snd_soc_ops storm_soc_ops = {
+	.hw_params	= storm_ops_hw_params,
+};
+
+static struct snd_soc_dai_link storm_dai_link = {
+	.name		= "Primary",
+	.stream_name	= "Primary",
+	.codec_dai_name	= "HiFi",
+	.ops		= &storm_soc_ops,
+};
+
+static struct snd_soc_card storm_soc_card = {
+	.name	= "ipq806x-storm",
+	.dev	= NULL,
+};
+
+static int storm_parse_of(struct snd_soc_card *card)
+{
+	struct snd_soc_dai_link *dai_link = card->dai_link;
+	struct device_node *np = card->dev->of_node;
+
+	dai_link->cpu_of_node = of_parse_phandle(np, "cpu", 0);
+	if (!dai_link->cpu_of_node) {
+		dev_err(card->dev, "%s() error getting cpu phandle\n",
+				__func__);
+		return -EINVAL;
+	}
+	dai_link->platform_of_node = dai_link->cpu_of_node;
+
+	dai_link->codec_of_node = of_parse_phandle(np, "codec", 0);
+	if (!dai_link->codec_of_node) {
+		dev_err(card->dev, "%s() error getting codec phandle\n",
+				__func__);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int storm_platform_probe(struct platform_device *pdev)
+{
+	struct snd_soc_card *card = &storm_soc_card;
+	int ret;
+
+	if (card->dev) {
+		dev_err(&pdev->dev, "%s() error, existing soundcard\n",
+				__func__);
+		return -ENODEV;
+	}
+	card->dev = &pdev->dev;
+	platform_set_drvdata(pdev, card);
+
+	ret = snd_soc_of_parse_card_name(card, "qcom,model");
+	if (ret) {
+		dev_err(&pdev->dev, "%s() error parsing card name: %d\n",
+				__func__, ret);
+		return ret;
+	}
+
+	card->dai_link	= &storm_dai_link;
+	card->num_links	= 1;
+
+	ret = storm_parse_of(card);
+	if (ret) {
+		dev_err(&pdev->dev, "%s() error resolving dai links: %d\n",
+				__func__, ret);
+		return ret;
+	}
+
+	ret = devm_snd_soc_register_card(&pdev->dev, card);
+	if (ret == -EPROBE_DEFER) {
+		card->dev = NULL;
+		return ret;
+	} else if (ret) {
+		dev_err(&pdev->dev, "%s() error registering soundcard: %d\n",
+				__func__, ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id storm_device_id[]  = {
+	{ .compatible = "google,storm-audio" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, storm_device_id);
+#endif
+
+static struct platform_driver storm_platform_driver = {
+	.driver = {
+		.name = "storm-audio",
+		.of_match_table =
+			of_match_ptr(storm_device_id),
+	},
+	.probe = storm_platform_probe,
+};
+module_platform_driver(storm_platform_driver);
+
+MODULE_DESCRIPTION("QTi IPQ806x-based Storm Machine Driver");
+MODULE_LICENSE("GPL v2");