[linux.git] / drivers / dma / lpc18xx-dmamux.c

/*
 * DMA Router driver for LPC18xx/43xx DMA MUX
 *
 * Copyright (C) 2015 Joachim Eastwood <[email protected]>
 *
 * Based on TI DMA Crossbar driver by:
 *   Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com
 *   Author: Peter Ujfalusi <[email protected]>
 *
 * 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/err.h>
#include <linux/init.h>
#include <linux/mfd/syscon.h>
#include <linux/of_device.h>
#include <linux/of_dma.h>
#include <linux/regmap.h>
#include <linux/spinlock.h>

/* CREG register offset and macros for mux manipulation */
#define LPC18XX_CREG_DMAMUX		0x11c
#define LPC18XX_DMAMUX_VAL(v, n)	((v) << (n * 2))
#define LPC18XX_DMAMUX_MASK(n)		(0x3 << (n * 2))
#define LPC18XX_DMAMUX_MAX_VAL		0x3

struct lpc18xx_dmamux {
	u32 value;
	bool busy;
};

struct lpc18xx_dmamux_data {
	struct dma_router dmarouter;
	struct lpc18xx_dmamux *muxes;
	u32 dma_master_requests;
	u32 dma_mux_requests;
	struct regmap *reg;
	spinlock_t lock;
};

static void lpc18xx_dmamux_free(struct device *dev, void *route_data)
{
	struct lpc18xx_dmamux_data *dmamux = dev_get_drvdata(dev);
	struct lpc18xx_dmamux *mux = route_data;
	unsigned long flags;

	spin_lock_irqsave(&dmamux->lock, flags);
	mux->busy = false;
	spin_unlock_irqrestore(&dmamux->lock, flags);
}

static void *lpc18xx_dmamux_reserve(struct of_phandle_args *dma_spec,
				    struct of_dma *ofdma)
{
	struct platform_device *pdev = of_find_device_by_node(ofdma->of_node);
	struct lpc18xx_dmamux_data *dmamux = platform_get_drvdata(pdev);
	unsigned long flags;
	unsigned mux;

	if (dma_spec->args_count != 3) {
		dev_err(&pdev->dev, "invalid number of dma mux args\n");
		return ERR_PTR(-EINVAL);
	}

	mux = dma_spec->args[0];
	if (mux >= dmamux->dma_master_requests) {
		dev_err(&pdev->dev, "invalid mux number: %d\n",
			dma_spec->args[0]);
		return ERR_PTR(-EINVAL);
	}

	if (dma_spec->args[1] > LPC18XX_DMAMUX_MAX_VAL) {
		dev_err(&pdev->dev, "invalid dma mux value: %d\n",
			dma_spec->args[1]);
		return ERR_PTR(-EINVAL);
	}

	/* The of_node_put() will be done in the core for the node */
	dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", 0);
	if (!dma_spec->np) {
		dev_err(&pdev->dev, "can't get dma master\n");
		return ERR_PTR(-EINVAL);
	}

	spin_lock_irqsave(&dmamux->lock, flags);
	if (dmamux->muxes[mux].busy) {
		spin_unlock_irqrestore(&dmamux->lock, flags);
		dev_err(&pdev->dev, "dma request %u busy with %u.%u\n",
			mux, mux, dmamux->muxes[mux].value);
		of_node_put(dma_spec->np);
		return ERR_PTR(-EBUSY);
	}

	dmamux->muxes[mux].busy = true;
	dmamux->muxes[mux].value = dma_spec->args[1];

	regmap_update_bits(dmamux->reg, LPC18XX_CREG_DMAMUX,
			   LPC18XX_DMAMUX_MASK(mux),
			   LPC18XX_DMAMUX_VAL(dmamux->muxes[mux].value, mux));
	spin_unlock_irqrestore(&dmamux->lock, flags);

	dma_spec->args[1] = dma_spec->args[2];
	dma_spec->args_count = 2;

	dev_dbg(&pdev->dev, "mapping dmamux %u.%u to dma request %u\n", mux,
		dmamux->muxes[mux].value, mux);

	return &dmamux->muxes[mux];
}

static int lpc18xx_dmamux_probe(struct platform_device *pdev)
{
	struct device_node *dma_np, *np = pdev->dev.of_node;
	struct lpc18xx_dmamux_data *dmamux;
	int ret;

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

	dmamux->reg = syscon_regmap_lookup_by_compatible("nxp,lpc1850-creg");
	if (IS_ERR(dmamux->reg)) {
		dev_err(&pdev->dev, "syscon lookup failed\n");
		return PTR_ERR(dmamux->reg);
	}

	ret = of_property_read_u32(np, "dma-requests",
				   &dmamux->dma_mux_requests);
	if (ret) {
		dev_err(&pdev->dev, "missing dma-requests property\n");
		return ret;
	}

	dma_np = of_parse_phandle(np, "dma-masters", 0);
	if (!dma_np) {
		dev_err(&pdev->dev, "can't get dma master\n");
		return -ENODEV;
	}

	ret = of_property_read_u32(dma_np, "dma-requests",
				   &dmamux->dma_master_requests);
	of_node_put(dma_np);
	if (ret) {
		dev_err(&pdev->dev, "missing master dma-requests property\n");
		return ret;
	}

	dmamux->muxes = devm_kcalloc(&pdev->dev, dmamux->dma_master_requests,
				     sizeof(struct lpc18xx_dmamux),
				     GFP_KERNEL);
	if (!dmamux->muxes)
		return -ENOMEM;

	spin_lock_init(&dmamux->lock);
	platform_set_drvdata(pdev, dmamux);
	dmamux->dmarouter.dev = &pdev->dev;
	dmamux->dmarouter.route_free = lpc18xx_dmamux_free;

	return of_dma_router_register(np, lpc18xx_dmamux_reserve,
				      &dmamux->dmarouter);
}

static const struct of_device_id lpc18xx_dmamux_match[] = {
	{ .compatible = "nxp,lpc1850-dmamux" },
	{},
};

static struct platform_driver lpc18xx_dmamux_driver = {
	.probe	= lpc18xx_dmamux_probe,
	.driver = {
		.name = "lpc18xx-dmamux",
		.of_match_table = lpc18xx_dmamux_match,
	},
};

static int __init lpc18xx_dmamux_init(void)
{
	return platform_driver_register(&lpc18xx_dmamux_driver);
}
arch_initcall(lpc18xx_dmamux_init);
Commit	Line	Data
e5f4ae84 JE	1	/*
	2	* DMA Router driver for LPC18xx/43xx DMA MUX
	3	*
	4	* Copyright (C) 2015 Joachim Eastwood <[email protected]>
	5	*
	6	* Based on TI DMA Crossbar driver by:
	7	* Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com
	8	* Author: Peter Ujfalusi <[email protected]>
	9	*
	10	* This program is free software; you can redistribute it and/or modify
	11	* it under the terms of the GNU General Public License version 2 as
	12	* published by the Free Software Foundation.
	13	*
	14	*/
	15
	16	#include <linux/err.h>
	17	#include <linux/init.h>
	18	#include <linux/mfd/syscon.h>
	19	#include <linux/of_device.h>
	20	#include <linux/of_dma.h>
	21	#include <linux/regmap.h>
	22	#include <linux/spinlock.h>
	23
	24	/* CREG register offset and macros for mux manipulation */
	25	#define LPC18XX_CREG_DMAMUX 0x11c
	26	#define LPC18XX_DMAMUX_VAL(v, n) ((v) << (n * 2))
	27	#define LPC18XX_DMAMUX_MASK(n) (0x3 << (n * 2))
	28	#define LPC18XX_DMAMUX_MAX_VAL 0x3
	29
	30	struct lpc18xx_dmamux {
	31	u32 value;
	32	bool busy;
	33	};
	34
	35	struct lpc18xx_dmamux_data {
	36	struct dma_router dmarouter;
	37	struct lpc18xx_dmamux *muxes;
	38	u32 dma_master_requests;
	39	u32 dma_mux_requests;
	40	struct regmap *reg;
	41	spinlock_t lock;
	42	};
	43
	44	static void lpc18xx_dmamux_free(struct device dev, void route_data)
	45	{
	46	struct lpc18xx_dmamux_data *dmamux = dev_get_drvdata(dev);
	47	struct lpc18xx_dmamux *mux = route_data;
	48	unsigned long flags;
	49
	50	spin_lock_irqsave(&dmamux->lock, flags);
	51	mux->busy = false;
	52	spin_unlock_irqrestore(&dmamux->lock, flags);
	53	}
	54
	55	static void lpc18xx_dmamux_reserve(struct of_phandle_args dma_spec,
	56	struct of_dma *ofdma)
	57	{
	58	struct platform_device *pdev = of_find_device_by_node(ofdma->of_node);
	59	struct lpc18xx_dmamux_data *dmamux = platform_get_drvdata(pdev);
	60	unsigned long flags;
	61	unsigned mux;
	62
	63	if (dma_spec->args_count != 3) {
	64	dev_err(&pdev->dev, "invalid number of dma mux args\n");
65	return ERR_PTR(-EINVAL);
66	}
67
68	mux = dma_spec->args[0];
69	if (mux >= dmamux->dma_master_requests) {
70	dev_err(&pdev->dev, "invalid mux number: %d\n",
71	dma_spec->args[0]);
72	return ERR_PTR(-EINVAL);
73	}
74
75	if (dma_spec->args[1] > LPC18XX_DMAMUX_MAX_VAL) {
76	dev_err(&pdev->dev, "invalid dma mux value: %d\n",
77	dma_spec->args[1]);
78	return ERR_PTR(-EINVAL);
79	}
80
81	/* The of_node_put() will be done in the core for the node */
82	dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", 0);
83	if (!dma_spec->np) {
84	dev_err(&pdev->dev, "can't get dma master\n");
85	return ERR_PTR(-EINVAL);
86	}
87
88	spin_lock_irqsave(&dmamux->lock, flags);
89	if (dmamux->muxes[mux].busy) {
90	spin_unlock_irqrestore(&dmamux->lock, flags);
91	dev_err(&pdev->dev, "dma request %u busy with %u.%u\n",
92	mux, mux, dmamux->muxes[mux].value);
93	of_node_put(dma_spec->np);
94	return ERR_PTR(-EBUSY);
95	}
96
97	dmamux->muxes[mux].busy = true;
98	dmamux->muxes[mux].value = dma_spec->args[1];
99
100	regmap_update_bits(dmamux->reg, LPC18XX_CREG_DMAMUX,
101	LPC18XX_DMAMUX_MASK(mux),
102	LPC18XX_DMAMUX_VAL(dmamux->muxes[mux].value, mux));
103	spin_unlock_irqrestore(&dmamux->lock, flags);
104
105	dma_spec->args[1] = dma_spec->args[2];
106	dma_spec->args_count = 2;
107
108	dev_dbg(&pdev->dev, "mapping dmamux %u.%u to dma request %u\n", mux,
109	dmamux->muxes[mux].value, mux);
110
111	return &dmamux->muxes[mux];
112	}
113
114	static int lpc18xx_dmamux_probe(struct platform_device *pdev)
115	{
116	struct device_node dma_np, np = pdev->dev.of_node;
117	struct lpc18xx_dmamux_data *dmamux;
118	int ret;
119
120	dmamux = devm_kzalloc(&pdev->dev, sizeof(*dmamux), GFP_KERNEL);
121	if (!dmamux)
122	return -ENOMEM;
123
124	dmamux->reg = syscon_regmap_lookup_by_compatible("nxp,lpc1850-creg");
125	if (IS_ERR(dmamux->reg)) {
126	dev_err(&pdev->dev, "syscon lookup failed\n");
127	return PTR_ERR(dmamux->reg);
128	}
129
130	ret = of_property_read_u32(np, "dma-requests",
131	&dmamux->dma_mux_requests);
132	if (ret) {
133	dev_err(&pdev->dev, "missing dma-requests property\n");
134	return ret;
135	}
136
137	dma_np = of_parse_phandle(np, "dma-masters", 0);
138	if (!dma_np) {
139	dev_err(&pdev->dev, "can't get dma master\n");
140	return -ENODEV;
141	}
142
143	ret = of_property_read_u32(dma_np, "dma-requests",
144	&dmamux->dma_master_requests);
145	of_node_put(dma_np);
146	if (ret) {
147	dev_err(&pdev->dev, "missing master dma-requests property\n");
148	return ret;
149	}
150
151	dmamux->muxes = devm_kcalloc(&pdev->dev, dmamux->dma_master_requests,
152	sizeof(struct lpc18xx_dmamux),
153	GFP_KERNEL);
154	if (!dmamux->muxes)
155	return -ENOMEM;
156
157	spin_lock_init(&dmamux->lock);
158	platform_set_drvdata(pdev, dmamux);
159	dmamux->dmarouter.dev = &pdev->dev;
160	dmamux->dmarouter.route_free = lpc18xx_dmamux_free;
161
162	return of_dma_router_register(np, lpc18xx_dmamux_reserve,
163	&dmamux->dmarouter);
164	}
165
166	static const struct of_device_id lpc18xx_dmamux_match[] = {
167	{ .compatible = "nxp,lpc1850-dmamux" },
168	{},
169	};
170
171	static struct platform_driver lpc18xx_dmamux_driver = {
172	.probe = lpc18xx_dmamux_probe,
173	.driver = {
174	.name = "lpc18xx-dmamux",
175	.of_match_table = lpc18xx_dmamux_match,
176	},
177	};
178
179	static int __init lpc18xx_dmamux_init(void)
180	{
181	return platform_driver_register(&lpc18xx_dmamux_driver);
182	}
183	arch_initcall(lpc18xx_dmamux_init);