1 /*
2 * linux/arch/arm/mach-pxa/ssp.c
3 *
4 * based on linux/arch/arm/mach-sa1100/ssp.c by Russell King
5 *
6 * Copyright (C) 2003 Russell King.
7 * Copyright (C) 2003 Wolfson Microelectronics PLC
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 *
13 * PXA2xx SSP driver. This provides the generic core for simple
14 * IO-based SSP applications and allows easy port setup for DMA access.
15 *
16 * Author: Liam Girdwood <liam.girdwood@wolfsonmicro.com>
17 */
18
19 #include <linux/module.h>
20 #include <linux/kernel.h>
21 #include <linux/sched.h>
22 #include <linux/slab.h>
23 #include <linux/errno.h>
24 #include <linux/interrupt.h>
25 #include <linux/ioport.h>
26 #include <linux/init.h>
27 #include <linux/mutex.h>
28 #include <linux/clk.h>
29 #include <linux/err.h>
30 #include <linux/platform_device.h>
31 #include <linux/spi/pxa2xx_spi.h>
32 #include <linux/io.h>
33 #include <linux/of.h>
34 #include <linux/of_device.h>
35
36 #include <asm/irq.h>
37
38 static DEFINE_MUTEX(ssp_lock);
39 static LIST_HEAD(ssp_list);
40
pxa_ssp_request(int port,const char * label)41 struct ssp_device *pxa_ssp_request(int port, const char *label)
42 {
43 struct ssp_device *ssp = NULL;
44
45 mutex_lock(&ssp_lock);
46
47 list_for_each_entry(ssp, &ssp_list, node) {
48 if (ssp->port_id == port && ssp->use_count == 0) {
49 ssp->use_count++;
50 ssp->label = label;
51 break;
52 }
53 }
54
55 mutex_unlock(&ssp_lock);
56
57 if (&ssp->node == &ssp_list)
58 return NULL;
59
60 return ssp;
61 }
62 EXPORT_SYMBOL(pxa_ssp_request);
63
pxa_ssp_request_of(const struct device_node * of_node,const char * label)64 struct ssp_device *pxa_ssp_request_of(const struct device_node *of_node,
65 const char *label)
66 {
67 struct ssp_device *ssp = NULL;
68
69 mutex_lock(&ssp_lock);
70
71 list_for_each_entry(ssp, &ssp_list, node) {
72 if (ssp->of_node == of_node && ssp->use_count == 0) {
73 ssp->use_count++;
74 ssp->label = label;
75 break;
76 }
77 }
78
79 mutex_unlock(&ssp_lock);
80
81 if (&ssp->node == &ssp_list)
82 return NULL;
83
84 return ssp;
85 }
86 EXPORT_SYMBOL(pxa_ssp_request_of);
87
pxa_ssp_free(struct ssp_device * ssp)88 void pxa_ssp_free(struct ssp_device *ssp)
89 {
90 mutex_lock(&ssp_lock);
91 if (ssp->use_count) {
92 ssp->use_count--;
93 ssp->label = NULL;
94 } else
95 dev_err(&ssp->pdev->dev, "device already free\n");
96 mutex_unlock(&ssp_lock);
97 }
98 EXPORT_SYMBOL(pxa_ssp_free);
99
100 #ifdef CONFIG_OF
101 static const struct of_device_id pxa_ssp_of_ids[] = {
102 { .compatible = "mrvl,pxa25x-ssp", .data = (void *) PXA25x_SSP },
103 { .compatible = "mvrl,pxa25x-nssp", .data = (void *) PXA25x_NSSP },
104 { .compatible = "mrvl,pxa27x-ssp", .data = (void *) PXA27x_SSP },
105 { .compatible = "mrvl,pxa3xx-ssp", .data = (void *) PXA3xx_SSP },
106 { .compatible = "mvrl,pxa168-ssp", .data = (void *) PXA168_SSP },
107 { .compatible = "mrvl,pxa910-ssp", .data = (void *) PXA910_SSP },
108 { .compatible = "mrvl,ce4100-ssp", .data = (void *) CE4100_SSP },
109 { },
110 };
111 MODULE_DEVICE_TABLE(of, pxa_ssp_of_ids);
112 #endif
113
pxa_ssp_probe(struct platform_device * pdev)114 static int pxa_ssp_probe(struct platform_device *pdev)
115 {
116 struct resource *res;
117 struct ssp_device *ssp;
118 struct device *dev = &pdev->dev;
119
120 ssp = devm_kzalloc(dev, sizeof(struct ssp_device), GFP_KERNEL);
121 if (ssp == NULL)
122 return -ENOMEM;
123
124 ssp->pdev = pdev;
125
126 ssp->clk = devm_clk_get(dev, NULL);
127 if (IS_ERR(ssp->clk))
128 return PTR_ERR(ssp->clk);
129
130 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
131 if (res == NULL) {
132 dev_err(dev, "no memory resource defined\n");
133 return -ENODEV;
134 }
135
136 res = devm_request_mem_region(dev, res->start, resource_size(res),
137 pdev->name);
138 if (res == NULL) {
139 dev_err(dev, "failed to request memory resource\n");
140 return -EBUSY;
141 }
142
143 ssp->phys_base = res->start;
144
145 ssp->mmio_base = devm_ioremap(dev, res->start, resource_size(res));
146 if (ssp->mmio_base == NULL) {
147 dev_err(dev, "failed to ioremap() registers\n");
148 return -ENODEV;
149 }
150
151 ssp->irq = platform_get_irq(pdev, 0);
152 if (ssp->irq < 0) {
153 dev_err(dev, "no IRQ resource defined\n");
154 return -ENODEV;
155 }
156
157 if (dev->of_node) {
158 const struct of_device_id *id =
159 of_match_device(of_match_ptr(pxa_ssp_of_ids), dev);
160 ssp->type = (int) id->data;
161 } else {
162 const struct platform_device_id *id =
163 platform_get_device_id(pdev);
164 ssp->type = (int) id->driver_data;
165
166 /* PXA2xx/3xx SSP ports starts from 1 and the internal pdev->id
167 * starts from 0, do a translation here
168 */
169 ssp->port_id = pdev->id + 1;
170 }
171
172 ssp->use_count = 0;
173 ssp->of_node = dev->of_node;
174
175 mutex_lock(&ssp_lock);
176 list_add(&ssp->node, &ssp_list);
177 mutex_unlock(&ssp_lock);
178
179 platform_set_drvdata(pdev, ssp);
180
181 return 0;
182 }
183
pxa_ssp_remove(struct platform_device * pdev)184 static int pxa_ssp_remove(struct platform_device *pdev)
185 {
186 struct ssp_device *ssp;
187
188 ssp = platform_get_drvdata(pdev);
189 if (ssp == NULL)
190 return -ENODEV;
191
192 mutex_lock(&ssp_lock);
193 list_del(&ssp->node);
194 mutex_unlock(&ssp_lock);
195
196 return 0;
197 }
198
199 static const struct platform_device_id ssp_id_table[] = {
200 { "pxa25x-ssp", PXA25x_SSP },
201 { "pxa25x-nssp", PXA25x_NSSP },
202 { "pxa27x-ssp", PXA27x_SSP },
203 { "pxa3xx-ssp", PXA3xx_SSP },
204 { "pxa168-ssp", PXA168_SSP },
205 { "pxa910-ssp", PXA910_SSP },
206 { },
207 };
208
209 static struct platform_driver pxa_ssp_driver = {
210 .probe = pxa_ssp_probe,
211 .remove = pxa_ssp_remove,
212 .driver = {
213 .name = "pxa2xx-ssp",
214 .of_match_table = of_match_ptr(pxa_ssp_of_ids),
215 },
216 .id_table = ssp_id_table,
217 };
218
pxa_ssp_init(void)219 static int __init pxa_ssp_init(void)
220 {
221 return platform_driver_register(&pxa_ssp_driver);
222 }
223
pxa_ssp_exit(void)224 static void __exit pxa_ssp_exit(void)
225 {
226 platform_driver_unregister(&pxa_ssp_driver);
227 }
228
229 arch_initcall(pxa_ssp_init);
230 module_exit(pxa_ssp_exit);
231
232 MODULE_DESCRIPTION("PXA SSP driver");
233 MODULE_AUTHOR("Liam Girdwood");
234 MODULE_LICENSE("GPL");
235