sound/soc/stm/stm32_sai.c

/*
 * STM32 ALSA SoC Digital Audio Interface (SAI) driver.
 *
 * Copyright (C) 2016, STMicroelectronics - All Rights Reserved
 * Author(s): Olivier Moysan <olivier.moysan@st.com> for STMicroelectronics.
 *
 * License terms: GPL V2.0.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License 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/clk.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/of_platform.h>
#include <linux/reset.h>

#include <sound/dmaengine_pcm.h>
#include <sound/core.h>

#include "stm32_sai.h"

static const struct of_device_id stm32_sai_ids[] = {
	{ .compatible = "st,stm32f4-sai", .data = (void *)SAI_STM32F4 },
	{}
};

static int stm32_sai_probe(struct platform_device *pdev)
{
	struct device_node *np = pdev->dev.of_node;
	struct stm32_sai_data *sai;
	struct reset_control *rst;
	struct resource *res;
	void __iomem *base;
	const struct of_device_id *of_id;

	sai = devm_kzalloc(&pdev->dev, sizeof(*sai), GFP_KERNEL);
	if (!sai)
		return -ENOMEM;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	base = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(base))
		return PTR_ERR(base);

	of_id = of_match_device(stm32_sai_ids, &pdev->dev);
	if (of_id)
		sai->version = (enum stm32_sai_version)of_id->data;
	else
		return -EINVAL;

	sai->clk_x8k = devm_clk_get(&pdev->dev, "x8k");
	if (IS_ERR(sai->clk_x8k)) {
		dev_err(&pdev->dev, "missing x8k parent clock\n");
		return PTR_ERR(sai->clk_x8k);
	}

	sai->clk_x11k = devm_clk_get(&pdev->dev, "x11k");
	if (IS_ERR(sai->clk_x11k)) {
		dev_err(&pdev->dev, "missing x11k parent clock\n");
		return PTR_ERR(sai->clk_x11k);
	}

	/* init irqs */
	sai->irq = platform_get_irq(pdev, 0);
	if (sai->irq < 0) {
		dev_err(&pdev->dev, "no irq for node %s\n", pdev->name);
		return sai->irq;
	}

	/* reset */
	rst = reset_control_get(&pdev->dev, NULL);
	if (!IS_ERR(rst)) {
		reset_control_assert(rst);
		udelay(2);
		reset_control_deassert(rst);
	}

	sai->pdev = pdev;
	platform_set_drvdata(pdev, sai);

	return of_platform_populate(np, NULL, NULL, &pdev->dev);
}

static int stm32_sai_remove(struct platform_device *pdev)
{
	of_platform_depopulate(&pdev->dev);

	return 0;
}

MODULE_DEVICE_TABLE(of, stm32_sai_ids);

static struct platform_driver stm32_sai_driver = {
	.driver = {
		.name = "st,stm32-sai",
		.of_match_table = stm32_sai_ids,
	},
	.probe = stm32_sai_probe,
	.remove = stm32_sai_remove,
};

module_platform_driver(stm32_sai_driver);

MODULE_DESCRIPTION("STM32 Soc SAI Interface");
MODULE_AUTHOR("Olivier Moysan, <olivier.moysan@st.com>");
MODULE_ALIAS("platform:st,stm32-sai");
MODULE_LICENSE("GPL v2");