summaryrefslogtreecommitdiffstats
path: root/arch/arm/plat-pxa/ssp.c
blob: ba13f793fbce45734b149e861481c0a33f996ac4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
/*
 *  linux/arch/arm/mach-pxa/ssp.c
 *
 *  based on linux/arch/arm/mach-sa1100/ssp.c by Russell King
 *
 *  Copyright (C) 2003 Russell King.
 *  Copyright (C) 2003 Wolfson Microelectronics PLC
 *
 * 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.
 *
 *  PXA2xx SSP driver.  This provides the generic core for simple
 *  IO-based SSP applications and allows easy port setup for DMA access.
 *
 *  Author: Liam Girdwood <liam.girdwood@wolfsonmicro.com>
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/mutex.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/spi/pxa2xx_spi.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_device.h>

#include <asm/irq.h>

static DEFINE_MUTEX(ssp_lock);
static LIST_HEAD(ssp_list);

struct ssp_device *pxa_ssp_request(int port, const char *label)
{
	struct ssp_device *ssp = NULL;

	mutex_lock(&ssp_lock);

	list_for_each_entry(ssp, &ssp_list, node) {
		if (ssp->port_id == port && ssp->use_count == 0) {
			ssp->use_count++;
			ssp->label = label;
			break;
		}
	}

	mutex_unlock(&ssp_lock);

	if (&ssp->node == &ssp_list)
		return NULL;

	return ssp;
}
EXPORT_SYMBOL(pxa_ssp_request);

struct ssp_device *pxa_ssp_request_of(const struct device_node *of_node,
				      const char *label)
{
	struct ssp_device *ssp = NULL;

	mutex_lock(&ssp_lock);

	list_for_each_entry(ssp, &ssp_list, node) {
		if (ssp->of_node == of_node && ssp->use_count == 0) {
			ssp->use_count++;
			ssp->label = label;
			break;
		}
	}

	mutex_unlock(&ssp_lock);

	if (&ssp->node == &ssp_list)
		return NULL;

	return ssp;
}
EXPORT_SYMBOL(pxa_ssp_request_of);

void pxa_ssp_free(struct ssp_device *ssp)
{
	mutex_lock(&ssp_lock);
	if (ssp->use_count) {
		ssp->use_count--;
		ssp->label = NULL;
	} else
		dev_err(&ssp->pdev->dev, "device already free\n");
	mutex_unlock(&ssp_lock);
}
EXPORT_SYMBOL(pxa_ssp_free);

#ifdef CONFIG_OF
static const struct of_device_id pxa_ssp_of_ids[] = {
	{ .compatible = "mrvl,pxa25x-ssp",	.data = (void *) PXA25x_SSP },
	{ .compatible = "mvrl,pxa25x-nssp",	.data = (void *) PXA25x_NSSP },
	{ .compatible = "mrvl,pxa27x-ssp",	.data = (void *) PXA27x_SSP },
	{ .compatible = "mrvl,pxa3xx-ssp",	.data = (void *) PXA3xx_SSP },
	{ .compatible = "mvrl,pxa168-ssp",	.data = (void *) PXA168_SSP },
	{ .compatible = "mrvl,pxa910-ssp",	.data = (void *) PXA910_SSP },
	{ .compatible = "mrvl,ce4100-ssp",	.data = (void *) CE4100_SSP },
	{ },
};
MODULE_DEVICE_TABLE(of, pxa_ssp_of_ids);
#endif

static int pxa_ssp_probe(struct platform_device *pdev)
{
	struct resource *res;
	struct ssp_device *ssp;
	struct device *dev = &pdev->dev;

	ssp = devm_kzalloc(dev, sizeof(struct ssp_device), GFP_KERNEL);
	if (ssp == NULL)
		return -ENOMEM;

	ssp->pdev = pdev;

	ssp->clk = devm_clk_get(dev, NULL);
	if (IS_ERR(ssp->clk))
		return PTR_ERR(ssp->clk);

	if (dev->of_node) {
		struct of_phandle_args dma_spec;
		struct device_node *np = dev->of_node;
		int ret;

		/*
		 * FIXME: we should allocate the DMA channel from this
		 * context and pass the channel down to the ssp users.
		 * For now, we lookup the rx and tx indices manually
		 */

		/* rx */
		ret = of_parse_phandle_with_args(np, "dmas", "#dma-cells",
						 0, &dma_spec);

		if (ret) {
			dev_err(dev, "Can't parse dmas property\n");
			return -ENODEV;
		}
		ssp->drcmr_rx = dma_spec.args[0];
		of_node_put(dma_spec.np);

		/* tx */
		ret = of_parse_phandle_with_args(np, "dmas", "#dma-cells",
						 1, &dma_spec);
		if (ret) {
			dev_err(dev, "Can't parse dmas property\n");
			return -ENODEV;
		}
		ssp->drcmr_tx = dma_spec.args[0];
		of_node_put(dma_spec.np);
	} else {
		res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
		if (res == NULL) {
			dev_err(dev, "no SSP RX DRCMR defined\n");
			return -ENODEV;
		}
		ssp->drcmr_rx = res->start;

		res = platform_get_resource(pdev, IORESOURCE_DMA, 1);
		if (res == NULL) {
			dev_err(dev, "no SSP TX DRCMR defined\n");
			return -ENODEV;
		}
		ssp->drcmr_tx = res->start;
	}

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (res == NULL) {
		dev_err(dev, "no memory resource defined\n");
		return -ENODEV;
	}

	res = devm_request_mem_region(dev, res->start, resource_size(res),
				      pdev->name);
	if (res == NULL) {
		dev_err(dev, "failed to request memory resource\n");
		return -EBUSY;
	}

	ssp->phys_base = res->start;

	ssp->mmio_base = devm_ioremap(dev, res->start, resource_size(res));
	if (ssp->mmio_base == NULL) {
		dev_err(dev, "failed to ioremap() registers\n");
		return -ENODEV;
	}

	ssp->irq = platform_get_irq(pdev, 0);
	if (ssp->irq < 0) {
		dev_err(dev, "no IRQ resource defined\n");
		return -ENODEV;
	}

	if (dev->of_node) {
		const struct of_device_id *id =
			of_match_device(of_match_ptr(pxa_ssp_of_ids), dev);
		ssp->type = (int) id->data;
	} else {
		const struct platform_device_id *id =
			platform_get_device_id(pdev);
		ssp->type = (int) id->driver_data;

		/* PXA2xx/3xx SSP ports starts from 1 and the internal pdev->id
		 * starts from 0, do a translation here
		 */
		ssp->port_id = pdev->id + 1;
	}

	ssp->use_count = 0;
	ssp->of_node = dev->of_node;

	mutex_lock(&ssp_lock);
	list_add(&ssp->node, &ssp_list);
	mutex_unlock(&ssp_lock);

	platform_set_drvdata(pdev, ssp);

	return 0;
}

static int pxa_ssp_remove(struct platform_device *pdev)
{
	struct resource *res;
	struct ssp_device *ssp;

	ssp = platform_get_drvdata(pdev);
	if (ssp == NULL)
		return -ENODEV;

	iounmap(ssp->mmio_base);

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	release_mem_region(res->start, resource_size(res));

	clk_put(ssp->clk);

	mutex_lock(&ssp_lock);
	list_del(&ssp->node);
	mutex_unlock(&ssp_lock);

	kfree(ssp);
	return 0;
}

static const struct platform_device_id ssp_id_table[] = {
	{ "pxa25x-ssp",		PXA25x_SSP },
	{ "pxa25x-nssp",	PXA25x_NSSP },
	{ "pxa27x-ssp",		PXA27x_SSP },
	{ "pxa3xx-ssp",		PXA3xx_SSP },
	{ "pxa168-ssp",		PXA168_SSP },
	{ "pxa910-ssp",		PXA910_SSP },
	{ },
};

static struct platform_driver pxa_ssp_driver = {
	.probe		= pxa_ssp_probe,
	.remove		= pxa_ssp_remove,
	.driver		= {
		.name		= "pxa2xx-ssp",
		.of_match_table	= of_match_ptr(pxa_ssp_of_ids),
	},
	.id_table	= ssp_id_table,
};

static int __init pxa_ssp_init(void)
{
	return platform_driver_register(&pxa_ssp_driver);
}

static void __exit pxa_ssp_exit(void)
{
	platform_driver_unregister(&pxa_ssp_driver);
}

arch_initcall(pxa_ssp_init);
module_exit(pxa_ssp_exit);

MODULE_DESCRIPTION("PXA SSP driver");
MODULE_AUTHOR("Liam Girdwood");
MODULE_LICENSE("GPL");
OpenPOWER on IntegriCloud