ssp.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 *  linux/arch/arm/mach-pxa/ssp.c
  4 *
  5 *  based on linux/arch/arm/mach-sa1100/ssp.c by Russell King
  6 *
  7 *  Copyright (C) 2003 Russell King.
  8 *  Copyright (C) 2003 Wolfson Microelectronics PLC
  9 *
 10 *  PXA2xx SSP driver.  This provides the generic core for simple
 11 *  IO-based SSP applications and allows easy port setup for DMA access.
 12 *
 13 *  Author: Liam Girdwood <liam.girdwood@wolfsonmicro.com>
 14 */
 15
 16#include <linux/module.h>
 17#include <linux/kernel.h>
 18#include <linux/sched.h>
 19#include <linux/slab.h>
 20#include <linux/errno.h>
 21#include <linux/interrupt.h>
 22#include <linux/ioport.h>
 23#include <linux/init.h>
 24#include <linux/mutex.h>
 25#include <linux/clk.h>
 26#include <linux/err.h>
 27#include <linux/platform_device.h>
 28#include <linux/pxa2xx_ssp.h>
 29#include <linux/io.h>
 30#include <linux/of.h>
 31#include <linux/of_device.h>
 32
 33#include <asm/irq.h>
 34
 35static DEFINE_MUTEX(ssp_lock);
 36static LIST_HEAD(ssp_list);
 37
 38struct ssp_device *pxa_ssp_request(int port, const char *label)
 39{
 40	struct ssp_device *ssp = NULL;
 41
 42	mutex_lock(&ssp_lock);
 43
 44	list_for_each_entry(ssp, &ssp_list, node) {
 45		if (ssp->port_id == port && ssp->use_count == 0) {
 46			ssp->use_count++;
 47			ssp->label = label;
 48			break;
 49		}
 50	}
 51
 52	mutex_unlock(&ssp_lock);
 53
 54	if (&ssp->node == &ssp_list)
 55		return NULL;
 56
 57	return ssp;
 58}
 59EXPORT_SYMBOL(pxa_ssp_request);
 60
 61struct ssp_device *pxa_ssp_request_of(const struct device_node *of_node,
 62				      const char *label)
 63{
 64	struct ssp_device *ssp = NULL;
 65
 66	mutex_lock(&ssp_lock);
 67
 68	list_for_each_entry(ssp, &ssp_list, node) {
 69		if (ssp->of_node == of_node && ssp->use_count == 0) {
 70			ssp->use_count++;
 71			ssp->label = label;
 72			break;
 73		}
 74	}
 75
 76	mutex_unlock(&ssp_lock);
 77
 78	if (&ssp->node == &ssp_list)
 79		return NULL;
 80
 81	return ssp;
 82}
 83EXPORT_SYMBOL(pxa_ssp_request_of);
 84
 85void pxa_ssp_free(struct ssp_device *ssp)
 86{
 87	mutex_lock(&ssp_lock);
 88	if (ssp->use_count) {
 89		ssp->use_count--;
 90		ssp->label = NULL;
 91	} else
 92		dev_err(ssp->dev, "device already free\n");
 93	mutex_unlock(&ssp_lock);
 94}
 95EXPORT_SYMBOL(pxa_ssp_free);
 96
 97#ifdef CONFIG_OF
 98static const struct of_device_id pxa_ssp_of_ids[] = {
 99	{ .compatible = "mrvl,pxa25x-ssp",	.data = (void *) PXA25x_SSP },
100	{ .compatible = "mvrl,pxa25x-nssp",	.data = (void *) PXA25x_NSSP },
101	{ .compatible = "mrvl,pxa27x-ssp",	.data = (void *) PXA27x_SSP },
102	{ .compatible = "mrvl,pxa3xx-ssp",	.data = (void *) PXA3xx_SSP },
103	{ .compatible = "mvrl,pxa168-ssp",	.data = (void *) PXA168_SSP },
104	{ .compatible = "mrvl,pxa910-ssp",	.data = (void *) PXA910_SSP },
105	{ .compatible = "mrvl,ce4100-ssp",	.data = (void *) CE4100_SSP },
106	{ },
107};
108MODULE_DEVICE_TABLE(of, pxa_ssp_of_ids);
109#endif
110
111static int pxa_ssp_probe(struct platform_device *pdev)
112{
113	struct resource *res;
114	struct ssp_device *ssp;
115	struct device *dev = &pdev->dev;
116
117	ssp = devm_kzalloc(dev, sizeof(struct ssp_device), GFP_KERNEL);
118	if (ssp == NULL)
119		return -ENOMEM;
120
121	ssp->dev = dev;
122
123	ssp->clk = devm_clk_get(dev, NULL);
124	if (IS_ERR(ssp->clk))
125		return PTR_ERR(ssp->clk);
126
127	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
128	if (res == NULL) {
129		dev_err(dev, "no memory resource defined\n");
130		return -ENODEV;
131	}
132
133	res = devm_request_mem_region(dev, res->start, resource_size(res),
134				      pdev->name);
135	if (res == NULL) {
136		dev_err(dev, "failed to request memory resource\n");
137		return -EBUSY;
138	}
139
140	ssp->phys_base = res->start;
141
142	ssp->mmio_base = devm_ioremap(dev, res->start, resource_size(res));
143	if (ssp->mmio_base == NULL) {
144		dev_err(dev, "failed to ioremap() registers\n");
145		return -ENODEV;
146	}
147
148	ssp->irq = platform_get_irq(pdev, 0);
149	if (ssp->irq < 0)
150		return -ENODEV;
151
152	if (dev->of_node) {
153		const struct of_device_id *id =
154			of_match_device(of_match_ptr(pxa_ssp_of_ids), dev);
155		ssp->type = (uintptr_t) id->data;
156	} else {
157		const struct platform_device_id *id =
158			platform_get_device_id(pdev);
159		ssp->type = id->driver_data;
160
161		/* PXA2xx/3xx SSP ports starts from 1 and the internal pdev->id
162		 * starts from 0, do a translation here
163		 */
164		ssp->port_id = pdev->id + 1;
165	}
166
167	ssp->use_count = 0;
168	ssp->of_node = dev->of_node;
169
170	mutex_lock(&ssp_lock);
171	list_add(&ssp->node, &ssp_list);
172	mutex_unlock(&ssp_lock);
173
174	platform_set_drvdata(pdev, ssp);
175
176	return 0;
177}
178
179static void pxa_ssp_remove(struct platform_device *pdev)
180{
181	struct ssp_device *ssp = platform_get_drvdata(pdev);
182
183	mutex_lock(&ssp_lock);
184	list_del(&ssp->node);
185	mutex_unlock(&ssp_lock);
186}
187
188static const struct platform_device_id ssp_id_table[] = {
189	{ "pxa25x-ssp",		PXA25x_SSP },
190	{ "pxa25x-nssp",	PXA25x_NSSP },
191	{ "pxa27x-ssp",		PXA27x_SSP },
192	{ "pxa3xx-ssp",		PXA3xx_SSP },
193	{ "pxa168-ssp",		PXA168_SSP },
194	{ "pxa910-ssp",		PXA910_SSP },
195	{ },
196};
197
198static struct platform_driver pxa_ssp_driver = {
199	.probe		= pxa_ssp_probe,
200	.remove		= pxa_ssp_remove,
201	.driver		= {
202		.name		= "pxa2xx-ssp",
203		.of_match_table	= of_match_ptr(pxa_ssp_of_ids),
204	},
205	.id_table	= ssp_id_table,
206};
207
208static int __init pxa_ssp_init(void)
209{
210	return platform_driver_register(&pxa_ssp_driver);
211}
212
213static void __exit pxa_ssp_exit(void)
214{
215	platform_driver_unregister(&pxa_ssp_driver);
216}
217
218arch_initcall(pxa_ssp_init);
219module_exit(pxa_ssp_exit);
220
221MODULE_DESCRIPTION("PXA SSP driver");
222MODULE_AUTHOR("Liam Girdwood");
223MODULE_LICENSE("GPL");