[linux-2.6-block.git] / drivers / dma / lpc18xx-dmamux.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * DMA Router driver for LPC18xx/43xx DMA MUX
 *
 * Copyright (C) 2015 Joachim Eastwood <manabian@gmail.com>
 *
 * Based on TI DMA Crossbar driver by:
 *   Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com
 *   Author: Peter Ujfalusi <peter.ujfalusi@ti.com>
 */

#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
d2912cb1	1	// SPDX-License-Identifier: GPL-2.0-only
e5f4ae84 JE	2	/*
	3	* DMA Router driver for LPC18xx/43xx DMA MUX
	4	*
	5	* Copyright (C) 2015 Joachim Eastwood <manabian@gmail.com>
	6	*
	7	* Based on TI DMA Crossbar driver by:
	8	* Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com
	9	* Author: Peter Ujfalusi <peter.ujfalusi@ti.com>
e5f4ae84 JE	10	*/
	11
	12	#include <linux/err.h>
	13	#include <linux/init.h>
	14	#include <linux/mfd/syscon.h>
	15	#include <linux/of_device.h>
	16	#include <linux/of_dma.h>
	17	#include <linux/regmap.h>
	18	#include <linux/spinlock.h>
	19
	20	/* CREG register offset and macros for mux manipulation */
	21	#define LPC18XX_CREG_DMAMUX 0x11c
	22	#define LPC18XX_DMAMUX_VAL(v, n) ((v) << (n * 2))
	23	#define LPC18XX_DMAMUX_MASK(n) (0x3 << (n * 2))
	24	#define LPC18XX_DMAMUX_MAX_VAL 0x3
	25
	26	struct lpc18xx_dmamux {
	27	u32 value;
	28	bool busy;
	29	};
	30
	31	struct lpc18xx_dmamux_data {
	32	struct dma_router dmarouter;
	33	struct lpc18xx_dmamux *muxes;
	34	u32 dma_master_requests;
	35	u32 dma_mux_requests;
	36	struct regmap *reg;
	37	spinlock_t lock;
	38	};
	39
	40	static void lpc18xx_dmamux_free(struct device dev, void route_data)
	41	{
	42	struct lpc18xx_dmamux_data *dmamux = dev_get_drvdata(dev);
	43	struct lpc18xx_dmamux *mux = route_data;
	44	unsigned long flags;
	45
	46	spin_lock_irqsave(&dmamux->lock, flags);
	47	mux->busy = false;
	48	spin_unlock_irqrestore(&dmamux->lock, flags);
	49	}
	50
	51	static void lpc18xx_dmamux_reserve(struct of_phandle_args dma_spec,
	52	struct of_dma *ofdma)
	53	{
	54	struct platform_device *pdev = of_find_device_by_node(ofdma->of_node);
	55	struct lpc18xx_dmamux_data *dmamux = platform_get_drvdata(pdev);
	56	unsigned long flags;
	57	unsigned mux;
	58
	59	if (dma_spec->args_count != 3) {
	60	dev_err(&pdev->dev, "invalid number of dma mux args\n");
	61	return ERR_PTR(-EINVAL);
	62	}
	63
	64	mux = dma_spec->args[0];
	65	if (mux >= dmamux->dma_master_requests) {
	66	dev_err(&pdev->dev, "invalid mux number: %d\n",
	67	dma_spec->args[0]);
	68	return ERR_PTR(-EINVAL);
	69	}
	70
	71	if (dma_spec->args[1] > LPC18XX_DMAMUX_MAX_VAL) {
	72	dev_err(&pdev->dev, "invalid dma mux value: %d\n",
	73	dma_spec->args[1]);
74	return ERR_PTR(-EINVAL);
75	}
76
77	/* The of_node_put() will be done in the core for the node */
78	dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", 0);
79	if (!dma_spec->np) {
80	dev_err(&pdev->dev, "can't get dma master\n");
81	return ERR_PTR(-EINVAL);
82	}
83
84	spin_lock_irqsave(&dmamux->lock, flags);
85	if (dmamux->muxes[mux].busy) {
86	spin_unlock_irqrestore(&dmamux->lock, flags);
87	dev_err(&pdev->dev, "dma request %u busy with %u.%u\n",
88	mux, mux, dmamux->muxes[mux].value);
89	of_node_put(dma_spec->np);
90	return ERR_PTR(-EBUSY);
91	}
92
93	dmamux->muxes[mux].busy = true;
94	dmamux->muxes[mux].value = dma_spec->args[1];
95
96	regmap_update_bits(dmamux->reg, LPC18XX_CREG_DMAMUX,
97	LPC18XX_DMAMUX_MASK(mux),
98	LPC18XX_DMAMUX_VAL(dmamux->muxes[mux].value, mux));
99	spin_unlock_irqrestore(&dmamux->lock, flags);
100
101	dma_spec->args[1] = dma_spec->args[2];
102	dma_spec->args_count = 2;
103
104	dev_dbg(&pdev->dev, "mapping dmamux %u.%u to dma request %u\n", mux,
105	dmamux->muxes[mux].value, mux);
106
107	return &dmamux->muxes[mux];
108	}
109
110	static int lpc18xx_dmamux_probe(struct platform_device *pdev)
111	{
112	struct device_node dma_np, np = pdev->dev.of_node;
113	struct lpc18xx_dmamux_data *dmamux;
114	int ret;
115
116	dmamux = devm_kzalloc(&pdev->dev, sizeof(*dmamux), GFP_KERNEL);
117	if (!dmamux)
118	return -ENOMEM;
119
120	dmamux->reg = syscon_regmap_lookup_by_compatible("nxp,lpc1850-creg");
121	if (IS_ERR(dmamux->reg)) {
122	dev_err(&pdev->dev, "syscon lookup failed\n");
123	return PTR_ERR(dmamux->reg);
124	}
125
126	ret = of_property_read_u32(np, "dma-requests",
127	&dmamux->dma_mux_requests);
128	if (ret) {
129	dev_err(&pdev->dev, "missing dma-requests property\n");
130	return ret;
131	}
132
133	dma_np = of_parse_phandle(np, "dma-masters", 0);
134	if (!dma_np) {
135	dev_err(&pdev->dev, "can't get dma master\n");
136	return -ENODEV;
137	}
138
139	ret = of_property_read_u32(dma_np, "dma-requests",
140	&dmamux->dma_master_requests);
141	of_node_put(dma_np);
142	if (ret) {
143	dev_err(&pdev->dev, "missing master dma-requests property\n");
144	return ret;
145	}
146
147	dmamux->muxes = devm_kcalloc(&pdev->dev, dmamux->dma_master_requests,
148	sizeof(struct lpc18xx_dmamux),
149	GFP_KERNEL);
150	if (!dmamux->muxes)
151	return -ENOMEM;
152
153	spin_lock_init(&dmamux->lock);
154	platform_set_drvdata(pdev, dmamux);
155	dmamux->dmarouter.dev = &pdev->dev;
156	dmamux->dmarouter.route_free = lpc18xx_dmamux_free;
157
158	return of_dma_router_register(np, lpc18xx_dmamux_reserve,
159	&dmamux->dmarouter);
160	}
161
162	static const struct of_device_id lpc18xx_dmamux_match[] = {
163	{ .compatible = "nxp,lpc1850-dmamux" },
164	{},
165	};
166
167	static struct platform_driver lpc18xx_dmamux_driver = {
168	.probe = lpc18xx_dmamux_probe,
169	.driver = {
170	.name = "lpc18xx-dmamux",
171	.of_match_table = lpc18xx_dmamux_match,
172	},
173	};
174
175	static int __init lpc18xx_dmamux_init(void)
176	{
177	return platform_driver_register(&lpc18xx_dmamux_driver);
178	}
179	arch_initcall(lpc18xx_dmamux_init);