[mirror_ubuntu-bionic-kernel.git] / drivers / misc / atmel-ssc.c

/*
 * Atmel SSC driver
 *
 * Copyright (C) 2007 Atmel Corporation
 *
 * 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.
 */

#include <linux/platform_device.h>
#include <linux/list.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/spinlock.h>
#include <linux/atmel-ssc.h>
#include <linux/slab.h>
#include <linux/module.h>

#include <linux/of.h>

/* Serialize access to ssc_list and user count */
static DEFINE_SPINLOCK(user_lock);
static LIST_HEAD(ssc_list);

struct ssc_device *ssc_request(unsigned int ssc_num)
{
	int ssc_valid = 0;
	struct ssc_device *ssc;

	spin_lock(&user_lock);
	list_for_each_entry(ssc, &ssc_list, list) {
		if (ssc->pdev->dev.of_node) {
			if (of_alias_get_id(ssc->pdev->dev.of_node, "ssc")
				== ssc_num) {
				ssc_valid = 1;
				break;
			}
		} else if (ssc->pdev->id == ssc_num) {
			ssc_valid = 1;
			break;
		}
	}

	if (!ssc_valid) {
		spin_unlock(&user_lock);
		pr_err("ssc: ssc%d platform device is missing\n", ssc_num);
		return ERR_PTR(-ENODEV);
	}

	if (ssc->user) {
		spin_unlock(&user_lock);
		dev_dbg(&ssc->pdev->dev, "module busy\n");
		return ERR_PTR(-EBUSY);
	}
	ssc->user++;
	spin_unlock(&user_lock);

	clk_prepare_enable(ssc->clk);

	return ssc;
}
EXPORT_SYMBOL(ssc_request);

void ssc_free(struct ssc_device *ssc)
{
	bool disable_clk = true;

	spin_lock(&user_lock);
	if (ssc->user)
		ssc->user--;
	else {
		disable_clk = false;
		dev_dbg(&ssc->pdev->dev, "device already free\n");
	}
	spin_unlock(&user_lock);

	if (disable_clk)
		clk_disable_unprepare(ssc->clk);
}
EXPORT_SYMBOL(ssc_free);

static struct atmel_ssc_platform_data at91rm9200_config = {
	.use_dma = 0,
};

static struct atmel_ssc_platform_data at91sam9g45_config = {
	.use_dma = 1,
};

static const struct platform_device_id atmel_ssc_devtypes[] = {
	{
		.name = "at91rm9200_ssc",
		.driver_data = (unsigned long) &at91rm9200_config,
	}, {
		.name = "at91sam9g45_ssc",
		.driver_data = (unsigned long) &at91sam9g45_config,
	}, {
		/* sentinel */
	}
};

#ifdef CONFIG_OF
static const struct of_device_id atmel_ssc_dt_ids[] = {
	{
		.compatible = "atmel,at91rm9200-ssc",
		.data = &at91rm9200_config,
	}, {
		.compatible = "atmel,at91sam9g45-ssc",
		.data = &at91sam9g45_config,
	}, {
		/* sentinel */
	}
};
MODULE_DEVICE_TABLE(of, atmel_ssc_dt_ids);
#endif

static inline const struct atmel_ssc_platform_data * __init
	atmel_ssc_get_driver_data(struct platform_device *pdev)
{
	if (pdev->dev.of_node) {
		const struct of_device_id *match;
		match = of_match_node(atmel_ssc_dt_ids, pdev->dev.of_node);
		if (match == NULL)
			return NULL;
		return match->data;
	}

	return (struct atmel_ssc_platform_data *)
		platform_get_device_id(pdev)->driver_data;
}

static int ssc_probe(struct platform_device *pdev)
{
	struct resource *regs;
	struct ssc_device *ssc;
	const struct atmel_ssc_platform_data *plat_dat;

	ssc = devm_kzalloc(&pdev->dev, sizeof(struct ssc_device), GFP_KERNEL);
	if (!ssc) {
		dev_dbg(&pdev->dev, "out of memory\n");
		return -ENOMEM;
	}

	ssc->pdev = pdev;

	plat_dat = atmel_ssc_get_driver_data(pdev);
	if (!plat_dat)
		return -ENODEV;
	ssc->pdata = (struct atmel_ssc_platform_data *)plat_dat;

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

	ssc->phybase = regs->start;

	ssc->clk = devm_clk_get(&pdev->dev, "pclk");
	if (IS_ERR(ssc->clk)) {
		dev_dbg(&pdev->dev, "no pclk clock defined\n");
		return -ENXIO;
	}

	/* disable all interrupts */
	clk_prepare_enable(ssc->clk);
	ssc_writel(ssc->regs, IDR, -1);
	ssc_readl(ssc->regs, SR);
	clk_disable_unprepare(ssc->clk);

	ssc->irq = platform_get_irq(pdev, 0);
	if (!ssc->irq) {
		dev_dbg(&pdev->dev, "could not get irq\n");
		return -ENXIO;
	}

	spin_lock(&user_lock);
	list_add_tail(&ssc->list, &ssc_list);
	spin_unlock(&user_lock);

	platform_set_drvdata(pdev, ssc);

	dev_info(&pdev->dev, "Atmel SSC device at 0x%p (irq %d)\n",
			ssc->regs, ssc->irq);

	return 0;
}

static int ssc_remove(struct platform_device *pdev)
{
	struct ssc_device *ssc = platform_get_drvdata(pdev);

	spin_lock(&user_lock);
	list_del(&ssc->list);
	spin_unlock(&user_lock);

	return 0;
}

static struct platform_driver ssc_driver = {
	.driver		= {
		.name		= "ssc",
		.owner		= THIS_MODULE,
		.of_match_table	= of_match_ptr(atmel_ssc_dt_ids),
	},
	.id_table	= atmel_ssc_devtypes,
	.probe		= ssc_probe,
	.remove		= ssc_remove,
};
module_platform_driver(ssc_driver);

MODULE_AUTHOR("Hans-Christian Egtvedt <hcegtvedt@atmel.com>");
MODULE_DESCRIPTION("SSC driver for Atmel AVR32 and AT91");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:ssc");
Commit	Line	Data
eb1f2930 HCE	1	/*
	2	* Atmel SSC driver
	3	*
	4	* Copyright (C) 2007 Atmel Corporation
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*/
	10
	11	#include <linux/platform_device.h>
	12	#include <linux/list.h>
	13	#include <linux/clk.h>
	14	#include <linux/err.h>
	15	#include <linux/io.h>
eb1f2930 HCE	16	#include <linux/spinlock.h>
eb1f2930 HCE	17	#include <linux/atmel-ssc.h>
5a0e3ad6	18	#include <linux/slab.h>
eb12a679	19	#include <linux/module.h>
eb1f2930	20
099343c6 BS	21	#include <linux/of.h>
099343c6 BS	22
eb1f2930 HCE	23	/* Serialize access to ssc_list and user count */
	24	static DEFINE_SPINLOCK(user_lock);
	25	static LIST_HEAD(ssc_list);
	26
	27	struct ssc_device *ssc_request(unsigned int ssc_num)
	28	{
	29	int ssc_valid = 0;
	30	struct ssc_device *ssc;
	31
	32	spin_lock(&user_lock);
	33	list_for_each_entry(ssc, &ssc_list, list) {
099343c6 BS	34	if (ssc->pdev->dev.of_node) {
	35	if (of_alias_get_id(ssc->pdev->dev.of_node, "ssc")
	36	== ssc_num) {
	37	ssc_valid = 1;
	38	break;
	39	}
	40	} else if (ssc->pdev->id == ssc_num) {
eb1f2930 HCE	41	ssc_valid = 1;
	42	break;
	43	}
	44	}
	45
	46	if (!ssc_valid) {
	47	spin_unlock(&user_lock);
dfecb716	48	pr_err("ssc: ssc%d platform device is missing\n", ssc_num);
eb1f2930 HCE	49	return ERR_PTR(-ENODEV);
	50	}
	51
	52	if (ssc->user) {
	53	spin_unlock(&user_lock);
	54	dev_dbg(&ssc->pdev->dev, "module busy\n");
	55	return ERR_PTR(-EBUSY);
	56	}
	57	ssc->user++;
	58	spin_unlock(&user_lock);
	59
6f0d9479	60	clk_prepare_enable(ssc->clk);
eb1f2930 HCE	61
	62	return ssc;
	63	}
	64	EXPORT_SYMBOL(ssc_request);
	65
	66	void ssc_free(struct ssc_device *ssc)
	67	{
9a9b1c61 BB	68	bool disable_clk = true;
9a9b1c61 BB	69
eb1f2930	70	spin_lock(&user_lock);
9a9b1c61	71	if (ssc->user)
eb1f2930	72	ssc->user--;
9a9b1c61 BB	73	else {
9a9b1c61 BB	74	disable_clk = false;
eb1f2930 HCE	75	dev_dbg(&ssc->pdev->dev, "device already free\n");
	76	}
	77	spin_unlock(&user_lock);
9a9b1c61 BB	78
	79	if (disable_clk)
	80	clk_disable_unprepare(ssc->clk);
eb1f2930 HCE	81	}
	82	EXPORT_SYMBOL(ssc_free);
	83
636036d2 BS	84	static struct atmel_ssc_platform_data at91rm9200_config = {
	85	.use_dma = 0,
	86	};
	87
	88	static struct atmel_ssc_platform_data at91sam9g45_config = {
	89	.use_dma = 1,
	90	};
	91
	92	static const struct platform_device_id atmel_ssc_devtypes[] = {
	93	{
	94	.name = "at91rm9200_ssc",
	95	.driver_data = (unsigned long) &at91rm9200_config,
	96	}, {
	97	.name = "at91sam9g45_ssc",
	98	.driver_data = (unsigned long) &at91sam9g45_config,
	99	}, {
	100	/* sentinel */
	101	}
	102	};
	103
099343c6 BS	104	#ifdef CONFIG_OF
	105	static const struct of_device_id atmel_ssc_dt_ids[] = {
	106	{
	107	.compatible = "atmel,at91rm9200-ssc",
	108	.data = &at91rm9200_config,
	109	}, {
	110	.compatible = "atmel,at91sam9g45-ssc",
	111	.data = &at91sam9g45_config,
	112	}, {
	113	/* sentinel */
	114	}
	115	};
	116	MODULE_DEVICE_TABLE(of, atmel_ssc_dt_ids);
	117	#endif
	118
	119	static inline const struct atmel_ssc_platform_data * __init
	120	atmel_ssc_get_driver_data(struct platform_device *pdev)
	121	{
	122	if (pdev->dev.of_node) {
	123	const struct of_device_id *match;
	124	match = of_match_node(atmel_ssc_dt_ids, pdev->dev.of_node);
	125	if (match == NULL)
	126	return NULL;
	127	return match->data;
	128	}
	129
	130	return (struct atmel_ssc_platform_data *)
	131	platform_get_device_id(pdev)->driver_data;
	132	}
	133
5c86ac69	134	static int ssc_probe(struct platform_device *pdev)
eb1f2930	135	{
eb1f2930 HCE	136	struct resource *regs;
eb1f2930 HCE	137	struct ssc_device *ssc;
099343c6	138	const struct atmel_ssc_platform_data *plat_dat;
eb1f2930	139
2e4de7b3	140	ssc = devm_kzalloc(&pdev->dev, sizeof(struct ssc_device), GFP_KERNEL);
eb1f2930 HCE	141	if (!ssc) {
eb1f2930 HCE	142	dev_dbg(&pdev->dev, "out of memory\n");
2e4de7b3	143	return -ENOMEM;
eb1f2930 HCE	144	}
eb1f2930 HCE	145
2e4de7b3	146	ssc->pdev = pdev;
099343c6 BS	147
	148	plat_dat = atmel_ssc_get_driver_data(pdev);
	149	if (!plat_dat)
	150	return -ENODEV;
	151	ssc->pdata = (struct atmel_ssc_platform_data *)plat_dat;
2e4de7b3	152
eb1f2930	153	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1684789f TR	154	ssc->regs = devm_ioremap_resource(&pdev->dev, regs);
	155	if (IS_ERR(ssc->regs))
	156	return PTR_ERR(ssc->regs);
2e4de7b3	157
31974361 NF	158	ssc->phybase = regs->start;
31974361 NF	159
2e4de7b3 BS	160	ssc->clk = devm_clk_get(&pdev->dev, "pclk");
	161	if (IS_ERR(ssc->clk)) {
	162	dev_dbg(&pdev->dev, "no pclk clock defined\n");
	163	return -ENXIO;
eb1f2930 HCE	164	}
	165
	166	/* disable all interrupts */
6f0d9479	167	clk_prepare_enable(ssc->clk);
f4319ff2	168	ssc_writel(ssc->regs, IDR, -1);
eb1f2930	169	ssc_readl(ssc->regs, SR);
6f0d9479	170	clk_disable_unprepare(ssc->clk);
eb1f2930 HCE	171
	172	ssc->irq = platform_get_irq(pdev, 0);
	173	if (!ssc->irq) {
	174	dev_dbg(&pdev->dev, "could not get irq\n");
2e4de7b3	175	return -ENXIO;
eb1f2930 HCE	176	}
	177
	178	spin_lock(&user_lock);
	179	list_add_tail(&ssc->list, &ssc_list);
	180	spin_unlock(&user_lock);
	181
	182	platform_set_drvdata(pdev, ssc);
	183
	184	dev_info(&pdev->dev, "Atmel SSC device at 0x%p (irq %d)\n",
	185	ssc->regs, ssc->irq);
	186
2e4de7b3	187	return 0;
eb1f2930 HCE	188	}
eb1f2930 HCE	189
486a5c28	190	static int ssc_remove(struct platform_device *pdev)
eb1f2930 HCE	191	{
	192	struct ssc_device *ssc = platform_get_drvdata(pdev);
	193
	194	spin_lock(&user_lock);
eb1f2930	195	list_del(&ssc->list);
eb1f2930 HCE	196	spin_unlock(&user_lock);
	197
	198	return 0;
	199	}
	200
	201	static struct platform_driver ssc_driver = {
eb1f2930 HCE	202	.driver = {
eb1f2930 HCE	203	.name = "ssc",
d6c23850	204	.owner = THIS_MODULE,
099343c6	205	.of_match_table = of_match_ptr(atmel_ssc_dt_ids),
eb1f2930	206	},
636036d2	207	.id_table = atmel_ssc_devtypes,
5c86ac69	208	.probe = ssc_probe,
046e7d68	209	.remove = ssc_remove,
eb1f2930	210	};
5c86ac69	211	module_platform_driver(ssc_driver);
eb1f2930 HCE	212
	213	MODULE_AUTHOR("Hans-Christian Egtvedt <hcegtvedt@atmel.com>");
	214	MODULE_DESCRIPTION("SSC driver for Atmel AVR32 and AT91");
	215	MODULE_LICENSE("GPL");
d6c23850	216	MODULE_ALIAS("platform:ssc");