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+/*
+ * 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.
+ *
+ * ipq806x-max98357a.c -- ALSA SoC machine driver for QTi ipq806x SOC with
+ * MAX98357a DAC
+ */
+
+#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 IPQ806X_MAX98357A_SYSCLK_MULT 4
+
+static int ipq806x_max98357a_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 * IPQ806X_MAX98357A_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 ipq806x_max98357a_soc_ops = {
+ .hw_params = ipq806x_max98357a_ops_hw_params,
+};
+
+static struct snd_soc_dai_link ipq806x_max98357a_dai_link = {
+ .name = "IPQ806x Media1",
+ .stream_name = "MultiMedia1",
+ .ops = &ipq806x_max98357a_soc_ops,
+};
+
+static struct snd_soc_card ipq806x_max98357a_soc_card = {
+ .name = "ipq806x-max98357a",
+ .dev = NULL,
+};
+
+static int ipq806x_max98357a_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;
+ int ret;
+
+ 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;
+ }
+
+ ret = of_property_read_string(np, "codec-dai",
+ &dai_link->codec_dai_name);
+ if (ret) {
+ dev_err(card->dev, "%s() error getting codec-dai: %d\n",
+ __func__, ret);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int ipq806x_max98357a_platform_probe(struct platform_device *pdev)
+{
+ struct snd_soc_card *card = &ipq806x_max98357a_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 = &ipq806x_max98357a_dai_link;
+ card->num_links = 1;
+
+ ret = ipq806x_max98357a_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 ipq806x_max98357a_device_id[] = {
+ { .compatible = "qcom,ipq806x-max98357a" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, ipq806x_max98357a_device_id);
+#endif
+
+static struct platform_driver ipq806x_max98357a_platform_driver = {
+ .driver = {
+ .name = "ipq806x-max98357a",
+ .of_match_table =
+ of_match_ptr(ipq806x_max98357a_device_id),
+ },
+ .probe = ipq806x_max98357a_platform_probe,
+};
+module_platform_driver(ipq806x_max98357a_platform_driver);
+
+MODULE_DESCRIPTION("QTi ipq806x-max98357a Machine Driver");
+MODULE_LICENSE("GPL v2");