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/spi/pxa2xx_spi.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(lock: &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(lock: &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(lock: &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, size: 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(ptr: ssp->clk))
125 return PTR_ERR(ptr: 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, offset: res->start, size: 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(new: &ssp->node, head: &ssp_list);
172 mutex_unlock(lock: &ssp_lock);
173
174 platform_set_drvdata(pdev, data: 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(entry: &ssp->node);
185 mutex_unlock(lock: &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_new = 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");
224

source code of linux/drivers/soc/pxa/ssp.c