[deliverable/linux.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>
#include <linux/pinctrl/consumer.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;
	struct pinctrl *pinctrl;

	pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
	if (IS_ERR(pinctrl)) {
		dev_err(&pdev->dev, "Failed to request pinctrl\n");
		return PTR_ERR(pinctrl);
	}

	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	21	#include <linux/of.h>
ea03c815	22	#include <linux/pinctrl/consumer.h>
099343c6	23
eb1f2930 HCE	24	/* Serialize access to ssc_list and user count */
	25	static DEFINE_SPINLOCK(user_lock);
	26	static LIST_HEAD(ssc_list);
	27
	28	struct ssc_device *ssc_request(unsigned int ssc_num)
	29	{
	30	int ssc_valid = 0;
	31	struct ssc_device *ssc;
	32
	33	spin_lock(&user_lock);
	34	list_for_each_entry(ssc, &ssc_list, list) {
099343c6 BS	35	if (ssc->pdev->dev.of_node) {
	36	if (of_alias_get_id(ssc->pdev->dev.of_node, "ssc")
	37	== ssc_num) {
	38	ssc_valid = 1;
	39	break;
	40	}
	41	} else if (ssc->pdev->id == ssc_num) {
eb1f2930 HCE	42	ssc_valid = 1;
	43	break;
	44	}
	45	}
	46
	47	if (!ssc_valid) {
	48	spin_unlock(&user_lock);
dfecb716	49	pr_err("ssc: ssc%d platform device is missing\n", ssc_num);
eb1f2930 HCE	50	return ERR_PTR(-ENODEV);
	51	}
	52
	53	if (ssc->user) {
	54	spin_unlock(&user_lock);
	55	dev_dbg(&ssc->pdev->dev, "module busy\n");
	56	return ERR_PTR(-EBUSY);
	57	}
	58	ssc->user++;
	59	spin_unlock(&user_lock);
	60
6f0d9479	61	clk_prepare_enable(ssc->clk);
eb1f2930 HCE	62
	63	return ssc;
	64	}
	65	EXPORT_SYMBOL(ssc_request);
	66
	67	void ssc_free(struct ssc_device *ssc)
	68	{
9a9b1c61 BB	69	bool disable_clk = true;
9a9b1c61 BB	70
eb1f2930	71	spin_lock(&user_lock);
9a9b1c61	72	if (ssc->user)
eb1f2930	73	ssc->user--;
9a9b1c61 BB	74	else {
9a9b1c61 BB	75	disable_clk = false;
eb1f2930 HCE	76	dev_dbg(&ssc->pdev->dev, "device already free\n");
	77	}
	78	spin_unlock(&user_lock);
9a9b1c61 BB	79
	80	if (disable_clk)
	81	clk_disable_unprepare(ssc->clk);
eb1f2930 HCE	82	}
	83	EXPORT_SYMBOL(ssc_free);
	84
636036d2 BS	85	static struct atmel_ssc_platform_data at91rm9200_config = {
	86	.use_dma = 0,
	87	};
	88
	89	static struct atmel_ssc_platform_data at91sam9g45_config = {
	90	.use_dma = 1,
	91	};
	92
	93	static const struct platform_device_id atmel_ssc_devtypes[] = {
	94	{
	95	.name = "at91rm9200_ssc",
	96	.driver_data = (unsigned long) &at91rm9200_config,
	97	}, {
	98	.name = "at91sam9g45_ssc",
	99	.driver_data = (unsigned long) &at91sam9g45_config,
	100	}, {
	101	/* sentinel */
	102	}
	103	};
	104
099343c6 BS	105	#ifdef CONFIG_OF
	106	static const struct of_device_id atmel_ssc_dt_ids[] = {
	107	{
	108	.compatible = "atmel,at91rm9200-ssc",
	109	.data = &at91rm9200_config,
	110	}, {
	111	.compatible = "atmel,at91sam9g45-ssc",
	112	.data = &at91sam9g45_config,
	113	}, {
	114	/* sentinel */
	115	}
	116	};
	117	MODULE_DEVICE_TABLE(of, atmel_ssc_dt_ids);
	118	#endif
	119
	120	static inline const struct atmel_ssc_platform_data * __init
	121	atmel_ssc_get_driver_data(struct platform_device *pdev)
	122	{
	123	if (pdev->dev.of_node) {
	124	const struct of_device_id *match;
	125	match = of_match_node(atmel_ssc_dt_ids, pdev->dev.of_node);
	126	if (match == NULL)
	127	return NULL;
	128	return match->data;
	129	}
	130
	131	return (struct atmel_ssc_platform_data *)
	132	platform_get_device_id(pdev)->driver_data;
	133	}
	134
5c86ac69	135	static int ssc_probe(struct platform_device *pdev)
eb1f2930	136	{
eb1f2930 HCE	137	struct resource *regs;
eb1f2930 HCE	138	struct ssc_device *ssc;
099343c6	139	const struct atmel_ssc_platform_data *plat_dat;
ea03c815 BS	140	struct pinctrl *pinctrl;
	141
	142	pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
	143	if (IS_ERR(pinctrl)) {
	144	dev_err(&pdev->dev, "Failed to request pinctrl\n");
	145	return PTR_ERR(pinctrl);
	146	}
eb1f2930	147
2e4de7b3	148	ssc = devm_kzalloc(&pdev->dev, sizeof(struct ssc_device), GFP_KERNEL);
eb1f2930 HCE	149	if (!ssc) {
eb1f2930 HCE	150	dev_dbg(&pdev->dev, "out of memory\n");
2e4de7b3	151	return -ENOMEM;
eb1f2930 HCE	152	}
eb1f2930 HCE	153
2e4de7b3	154	ssc->pdev = pdev;
099343c6 BS	155
	156	plat_dat = atmel_ssc_get_driver_data(pdev);
	157	if (!plat_dat)
	158	return -ENODEV;
	159	ssc->pdata = (struct atmel_ssc_platform_data *)plat_dat;
2e4de7b3	160
eb1f2930	161	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1684789f TR	162	ssc->regs = devm_ioremap_resource(&pdev->dev, regs);
	163	if (IS_ERR(ssc->regs))
	164	return PTR_ERR(ssc->regs);
2e4de7b3	165
31974361 NF	166	ssc->phybase = regs->start;
31974361 NF	167
2e4de7b3 BS	168	ssc->clk = devm_clk_get(&pdev->dev, "pclk");
	169	if (IS_ERR(ssc->clk)) {
	170	dev_dbg(&pdev->dev, "no pclk clock defined\n");
	171	return -ENXIO;
eb1f2930 HCE	172	}
	173
	174	/* disable all interrupts */
6f0d9479	175	clk_prepare_enable(ssc->clk);
f4319ff2	176	ssc_writel(ssc->regs, IDR, -1);
eb1f2930	177	ssc_readl(ssc->regs, SR);
6f0d9479	178	clk_disable_unprepare(ssc->clk);
eb1f2930 HCE	179
	180	ssc->irq = platform_get_irq(pdev, 0);
	181	if (!ssc->irq) {
	182	dev_dbg(&pdev->dev, "could not get irq\n");
2e4de7b3	183	return -ENXIO;
eb1f2930 HCE	184	}
	185
	186	spin_lock(&user_lock);
	187	list_add_tail(&ssc->list, &ssc_list);
	188	spin_unlock(&user_lock);
	189
	190	platform_set_drvdata(pdev, ssc);
	191
	192	dev_info(&pdev->dev, "Atmel SSC device at 0x%p (irq %d)\n",
	193	ssc->regs, ssc->irq);
	194
2e4de7b3	195	return 0;
eb1f2930 HCE	196	}
eb1f2930 HCE	197
486a5c28	198	static int ssc_remove(struct platform_device *pdev)
eb1f2930 HCE	199	{
	200	struct ssc_device *ssc = platform_get_drvdata(pdev);
	201
	202	spin_lock(&user_lock);
eb1f2930	203	list_del(&ssc->list);
eb1f2930 HCE	204	spin_unlock(&user_lock);
	205
	206	return 0;
	207	}
	208
	209	static struct platform_driver ssc_driver = {
eb1f2930 HCE	210	.driver = {
eb1f2930 HCE	211	.name = "ssc",
d6c23850	212	.owner = THIS_MODULE,
099343c6	213	.of_match_table = of_match_ptr(atmel_ssc_dt_ids),
eb1f2930	214	},
636036d2	215	.id_table = atmel_ssc_devtypes,
5c86ac69	216	.probe = ssc_probe,
046e7d68	217	.remove = ssc_remove,
eb1f2930	218	};
5c86ac69	219	module_platform_driver(ssc_driver);
eb1f2930 HCE	220
	221	MODULE_AUTHOR("Hans-Christian Egtvedt <hcegtvedt@atmel.com>");
	222	MODULE_DESCRIPTION("SSC driver for Atmel AVR32 and AT91");
	223	MODULE_LICENSE("GPL");
d6c23850	224	MODULE_ALIAS("platform:ssc");