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
35 static DEFINE_MUTEX(ssp_lock);
36 static LIST_HEAD(ssp_list);
37
pxa_ssp_request(int port,const char * label)38 struct 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 }
59 EXPORT_SYMBOL(pxa_ssp_request);
60
pxa_ssp_request_of(const struct device_node * of_node,const char * label)61 struct 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 }
83 EXPORT_SYMBOL(pxa_ssp_request_of);
84
pxa_ssp_free(struct ssp_device * ssp)85 void 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 }
95 EXPORT_SYMBOL(pxa_ssp_free);
96
97 #ifdef CONFIG_OF
98 static 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 };
108 MODULE_DEVICE_TABLE(of, pxa_ssp_of_ids);
109 #endif
110
pxa_ssp_probe(struct platform_device * pdev)111 static 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 dev_err(dev, "no IRQ resource defined\n");
151 return -ENODEV;
152 }
153
154 if (dev->of_node) {
155 const struct of_device_id *id =
156 of_match_device(of_match_ptr(pxa_ssp_of_ids), dev);
157 ssp->type = (int) id->data;
158 } else {
159 const struct platform_device_id *id =
160 platform_get_device_id(pdev);
161 ssp->type = (int) id->driver_data;
162
163 /* PXA2xx/3xx SSP ports starts from 1 and the internal pdev->id
164 * starts from 0, do a translation here
165 */
166 ssp->port_id = pdev->id + 1;
167 }
168
169 ssp->use_count = 0;
170 ssp->of_node = dev->of_node;
171
172 mutex_lock(&ssp_lock);
173 list_add(&ssp->node, &ssp_list);
174 mutex_unlock(&ssp_lock);
175
176 platform_set_drvdata(pdev, ssp);
177
178 return 0;
179 }
180
pxa_ssp_remove(struct platform_device * pdev)181 static int pxa_ssp_remove(struct platform_device *pdev)
182 {
183 struct ssp_device *ssp;
184
185 ssp = platform_get_drvdata(pdev);
186 if (ssp == NULL)
187 return -ENODEV;
188
189 mutex_lock(&ssp_lock);
190 list_del(&ssp->node);
191 mutex_unlock(&ssp_lock);
192
193 return 0;
194 }
195
196 static const struct platform_device_id ssp_id_table[] = {
197 { "pxa25x-ssp", PXA25x_SSP },
198 { "pxa25x-nssp", PXA25x_NSSP },
199 { "pxa27x-ssp", PXA27x_SSP },
200 { "pxa3xx-ssp", PXA3xx_SSP },
201 { "pxa168-ssp", PXA168_SSP },
202 { "pxa910-ssp", PXA910_SSP },
203 { },
204 };
205
206 static struct platform_driver pxa_ssp_driver = {
207 .probe = pxa_ssp_probe,
208 .remove = pxa_ssp_remove,
209 .driver = {
210 .name = "pxa2xx-ssp",
211 .of_match_table = of_match_ptr(pxa_ssp_of_ids),
212 },
213 .id_table = ssp_id_table,
214 };
215
pxa_ssp_init(void)216 static int __init pxa_ssp_init(void)
217 {
218 return platform_driver_register(&pxa_ssp_driver);
219 }
220
pxa_ssp_exit(void)221 static void __exit pxa_ssp_exit(void)
222 {
223 platform_driver_unregister(&pxa_ssp_driver);
224 }
225
226 arch_initcall(pxa_ssp_init);
227 module_exit(pxa_ssp_exit);
228
229 MODULE_DESCRIPTION("PXA SSP driver");
230 MODULE_AUTHOR("Liam Girdwood");
231 MODULE_LICENSE("GPL");
232