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+/* Copyright (c) 2010-2011,2013-2014 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.
+ */
+
+#include <linux/module.h>
+#include <linux/gpio.h>
+#include <sound/soc.h>
+
+#define DRV_NAME "max98357a-codec"
+
+enum pinctrl_pin_state {
+ STATE_DISABLED = 0,
+ STATE_ENABLED = 1
+};
+static const char * const pin_states[] = {"Disabled", "Enabled"};
+
+struct max98357a_codec_pinctrl {
+ struct pinctrl *pinctrl;
+ struct pinctrl_state *disabled;
+ struct pinctrl_state *enabled;
+ enum pinctrl_pin_state curr_state;
+};
+
+struct max98357a_codec_data {
+ struct gpio_desc *dac;
+ struct max98357a_codec_pinctrl mi2s;
+};
+
+static int max98357a_codec_set_pinctrl(struct max98357a_codec_pinctrl *mi2s)
+{
+ int ret;
+
+ pr_debug("%s: curr_state = %s\n", __func__,
+ pin_states[mi2s->curr_state]);
+
+ switch (mi2s->curr_state) {
+ case STATE_DISABLED:
+ ret = pinctrl_select_state(mi2s->pinctrl, mi2s->enabled);
+ if (ret) {
+ pr_err("%s: pinctrl_select_state failed with %d\n",
+ __func__, ret);
+ return -EIO;
+ }
+ mi2s->curr_state = STATE_ENABLED;
+ break;
+ case STATE_ENABLED:
+ pr_err("%s: MI2S pins already enabled\n", __func__);
+ break;
+ default:
+ pr_err("%s: MI2S pin state is invalid: %d\n", __func__,
+ mi2s->curr_state);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int max98357a_codec_reset_pinctrl(struct max98357a_codec_pinctrl *mi2s)
+{
+ int ret;
+
+ pr_debug("%s: curr_state = %s\n", __func__,
+ pin_states[mi2s->curr_state]);
+
+ switch (mi2s->curr_state) {
+ case STATE_ENABLED:
+ ret = pinctrl_select_state(mi2s->pinctrl, mi2s->disabled);
+ if (ret) {
+ pr_err("%s: pinctrl_select_state failed with %d\n",
+ __func__, ret);
+ return -EIO;
+ }
+ mi2s->curr_state = STATE_DISABLED;
+ break;
+ case STATE_DISABLED:
+ pr_err("%s: MI2S pins already disabled\n", __func__);
+ break;
+ default:
+ pr_err("%s: MI2S pin state is invalid: %d\n", __func__,
+ mi2s->curr_state);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int max98357a_codec_get_pinctrl(struct snd_soc_dai *dai)
+{
+ int ret;
+ struct max98357a_codec_data *prtd = snd_soc_dai_get_drvdata(dai);
+ struct max98357a_codec_pinctrl *mi2s = &prtd->mi2s;
+ struct pinctrl *pinctrl;
+
+ pinctrl = devm_pinctrl_get(dai->dev);
+ if (IS_ERR_OR_NULL(pinctrl)) {
+ dev_err(dai->dev, "%s: Unable to get pinctrl handle: %d\n",
+ __func__, PTR_ERR_OR_ZERO(pinctrl));
+ return -EINVAL;
+ }
+ mi2s->pinctrl = pinctrl;
+
+ /* get all the states handles from Device Tree */
+ mi2s->disabled = pinctrl_lookup_state(pinctrl, "mi2s-disabled");
+ if (IS_ERR(mi2s->disabled)) {
+ dev_err(dai->dev, "%s: could not get disabled pinstate: %d\n",
+ __func__, PTR_ERR_OR_ZERO(mi2s->disabled));
+ return -EINVAL;
+ }
+
+ mi2s->enabled = pinctrl_lookup_state(pinctrl, "mi2s-enabled");
+ if (IS_ERR(mi2s->enabled)) {
+ dev_err(dai->dev, "%s: could not get enabled pinstate: %d\n",
+ __func__, PTR_ERR_OR_ZERO(mi2s->enabled));
+ return -EINVAL;
+ }
+
+ /* Reset the MI2S pins to the disabled state */
+ ret = pinctrl_select_state(mi2s->pinctrl, mi2s->disabled);
+ if (ret) {
+ dev_err(dai->dev, "%s: Disable MI2S pins failed with %d\n",
+ __func__, ret);
+ return -EIO;
+ }
+ mi2s->curr_state = STATE_DISABLED;
+
+ return 0;
+}
+
+static int max98357a_codec_daiops_startup(struct snd_pcm_substream *substream,
+ struct snd_soc_dai *dai)
+{
+ int ret;
+ struct max98357a_codec_data *prtd = snd_soc_dai_get_drvdata(dai);
+
+ ret = max98357a_codec_set_pinctrl(&prtd->mi2s);
+ if (ret) {
+ dev_err(dai->dev, "%s: MI2S pinctrl set failed with %d\n",
+ __func__, ret);
+ return ret;
+ }
+
+ gpiod_set_value(prtd->dac, 1);
+
+ return 0;
+}
+
+static void max98357a_codec_daiops_shutdown(
+ struct snd_pcm_substream *substream, struct snd_soc_dai *dai)
+{
+ int ret;
+ struct max98357a_codec_data *prtd = snd_soc_dai_get_drvdata(dai);
+
+ gpiod_set_value(prtd->dac, 0);
+
+ ret = max98357a_codec_reset_pinctrl(&prtd->mi2s);
+ if (ret)
+ dev_err(dai->dev, "%s: MI2S pinctrl set failed with %d\n",
+ __func__, ret);
+}
+
+static struct snd_soc_dai_ops max98357a_codec_dai_ops = {
+ .startup = max98357a_codec_daiops_startup,
+ .shutdown = max98357a_codec_daiops_shutdown,
+};
+
+static int max98357a_codec_dai_probe(struct snd_soc_dai *dai)
+{
+ int ret;
+ struct max98357a_codec_data *prtd = snd_soc_dai_get_drvdata(dai);
+
+ prtd->dac = devm_gpiod_get(dai->dev, "dac");
+ if (IS_ERR(prtd->dac)) {
+ dev_err(dai->dev, "unable to get DAC GPIO\n");
+ return PTR_ERR(prtd->dac);
+ }
+ gpiod_direction_output(prtd->dac, 0);
+
+ ret = max98357a_codec_get_pinctrl(dai);
+ if (ret) {
+ dev_err(dai->dev, "%s: Parsing MI2S pinctrl failed: %d\n",
+ __func__, ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static struct snd_soc_dai_driver max98357a_codec_dai_driver = {
+ .name = "max98357a-codec-dai",
+ .playback = {
+ .stream_name = "max98357a-codec-playback",
+ .formats = SNDRV_PCM_FMTBIT_S16 |
+ SNDRV_PCM_FMTBIT_S24 |
+ SNDRV_PCM_FMTBIT_S32,
+ .rates = SNDRV_PCM_RATE_8000 |
+ SNDRV_PCM_RATE_16000 |
+ SNDRV_PCM_RATE_48000 |
+ SNDRV_PCM_RATE_96000,
+ .rate_min = 8000,
+ .rate_max = 96000,
+ .channels_min = 1,
+ .channels_max = 2,
+ },
+ .probe = &max98357a_codec_dai_probe,
+ .ops = &max98357a_codec_dai_ops,
+};
+
+static int max98357a_codec_platform_probe(struct platform_device *pdev)
+{
+ int ret;
+ struct max98357a_codec_data *prtd;
+ struct snd_soc_codec_driver *codec_driver;
+
+ prtd = devm_kzalloc(&pdev->dev, sizeof(struct max98357a_codec_data),
+ GFP_KERNEL);
+ if (!prtd)
+ return -ENOMEM;
+ platform_set_drvdata(pdev, prtd);
+
+ codec_driver = devm_kzalloc(&pdev->dev,
+ sizeof(struct snd_soc_codec_driver), GFP_KERNEL);
+ if (!codec_driver)
+ return -ENOMEM;
+
+ ret = snd_soc_register_codec(&pdev->dev, codec_driver,
+ &max98357a_codec_dai_driver, 1);
+ if (ret)
+ dev_err(&pdev->dev, "%s: error registering codec dais\n",
+ __func__);
+
+ return ret;
+}
+
+static int max98357a_codec_platform_remove(struct platform_device *pdev)
+{
+ snd_soc_unregister_codec(&pdev->dev);
+
+ return 0;
+}
+
+static const struct of_device_id max98357a_codec_dt_match[] = {
+ { .compatible = "qcom,max98357a-codec", },
+ {}
+};
+
+static struct platform_driver max98357a_codec_platform_driver = {
+ .driver = {
+ .name = DRV_NAME,
+ .of_match_table = max98357a_codec_dt_match,
+ },
+ .probe = max98357a_codec_platform_probe,
+ .remove = max98357a_codec_platform_remove,
+};
+module_platform_driver(max98357a_codec_platform_driver);
+
+MODULE_DESCRIPTION("QCOM MAX98357A CODEC DRIVER");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" DRV_NAME);
+MODULE_DEVICE_TABLE(of, max98357a_codec_dt_match);