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
34 #include <asm/irq.h>
35 #include <mach/hardware.h>
36
37 static DEFINE_MUTEX(ssp_lock);
38 static LIST_HEAD(ssp_list);
39
pxa_ssp_request(int port,const char * label)40 struct ssp_device *pxa_ssp_request(int port, const char *label)
41 {
42 struct ssp_device *ssp = NULL;
43
44 mutex_lock(&ssp_lock);
45
46 list_for_each_entry(ssp, &ssp_list, node) {
47 if (ssp->port_id == port && ssp->use_count == 0) {
48 ssp->use_count++;
49 ssp->label = label;
50 break;
51 }
52 }
53
54 mutex_unlock(&ssp_lock);
55
56 if (&ssp->node == &ssp_list)
57 return NULL;
58
59 return ssp;
60 }
61 EXPORT_SYMBOL(pxa_ssp_request);
62
pxa_ssp_free(struct ssp_device * ssp)63 void pxa_ssp_free(struct ssp_device *ssp)
64 {
65 mutex_lock(&ssp_lock);
66 if (ssp->use_count) {
67 ssp->use_count--;
68 ssp->label = NULL;
69 } else
70 dev_err(&ssp->pdev->dev, "device already free\n");
71 mutex_unlock(&ssp_lock);
72 }
73 EXPORT_SYMBOL(pxa_ssp_free);
74
pxa_ssp_probe(struct platform_device * pdev)75 static int __devinit pxa_ssp_probe(struct platform_device *pdev)
76 {
77 const struct platform_device_id *id = platform_get_device_id(pdev);
78 struct resource *res;
79 struct ssp_device *ssp;
80 int ret = 0;
81
82 ssp = kzalloc(sizeof(struct ssp_device), GFP_KERNEL);
83 if (ssp == NULL) {
84 dev_err(&pdev->dev, "failed to allocate memory");
85 return -ENOMEM;
86 }
87 ssp->pdev = pdev;
88
89 ssp->clk = clk_get(&pdev->dev, NULL);
90 if (IS_ERR(ssp->clk)) {
91 ret = PTR_ERR(ssp->clk);
92 goto err_free;
93 }
94
95 res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
96 if (res == NULL) {
97 dev_err(&pdev->dev, "no SSP RX DRCMR defined\n");
98 ret = -ENODEV;
99 goto err_free_clk;
100 }
101 ssp->drcmr_rx = res->start;
102
103 res = platform_get_resource(pdev, IORESOURCE_DMA, 1);
104 if (res == NULL) {
105 dev_err(&pdev->dev, "no SSP TX DRCMR defined\n");
106 ret = -ENODEV;
107 goto err_free_clk;
108 }
109 ssp->drcmr_tx = res->start;
110
111 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
112 if (res == NULL) {
113 dev_err(&pdev->dev, "no memory resource defined\n");
114 ret = -ENODEV;
115 goto err_free_clk;
116 }
117
118 res = request_mem_region(res->start, resource_size(res),
119 pdev->name);
120 if (res == NULL) {
121 dev_err(&pdev->dev, "failed to request memory resource\n");
122 ret = -EBUSY;
123 goto err_free_clk;
124 }
125
126 ssp->phys_base = res->start;
127
128 ssp->mmio_base = ioremap(res->start, resource_size(res));
129 if (ssp->mmio_base == NULL) {
130 dev_err(&pdev->dev, "failed to ioremap() registers\n");
131 ret = -ENODEV;
132 goto err_free_mem;
133 }
134
135 ssp->irq = platform_get_irq(pdev, 0);
136 if (ssp->irq < 0) {
137 dev_err(&pdev->dev, "no IRQ resource defined\n");
138 ret = -ENODEV;
139 goto err_free_io;
140 }
141
142 /* PXA2xx/3xx SSP ports starts from 1 and the internal pdev->id
143 * starts from 0, do a translation here
144 */
145 ssp->port_id = pdev->id + 1;
146 ssp->use_count = 0;
147 ssp->type = (int)id->driver_data;
148
149 mutex_lock(&ssp_lock);
150 list_add(&ssp->node, &ssp_list);
151 mutex_unlock(&ssp_lock);
152
153 platform_set_drvdata(pdev, ssp);
154 return 0;
155
156 err_free_io:
157 iounmap(ssp->mmio_base);
158 err_free_mem:
159 release_mem_region(res->start, resource_size(res));
160 err_free_clk:
161 clk_put(ssp->clk);
162 err_free:
163 kfree(ssp);
164 return ret;
165 }
166
pxa_ssp_remove(struct platform_device * pdev)167 static int __devexit pxa_ssp_remove(struct platform_device *pdev)
168 {
169 struct resource *res;
170 struct ssp_device *ssp;
171
172 ssp = platform_get_drvdata(pdev);
173 if (ssp == NULL)
174 return -ENODEV;
175
176 iounmap(ssp->mmio_base);
177
178 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
179 release_mem_region(res->start, resource_size(res));
180
181 clk_put(ssp->clk);
182
183 mutex_lock(&ssp_lock);
184 list_del(&ssp->node);
185 mutex_unlock(&ssp_lock);
186
187 kfree(ssp);
188 return 0;
189 }
190
191 static const struct platform_device_id ssp_id_table[] = {
192 { "pxa25x-ssp", PXA25x_SSP },
193 { "pxa25x-nssp", PXA25x_NSSP },
194 { "pxa27x-ssp", PXA27x_SSP },
195 { "pxa168-ssp", PXA168_SSP },
196 { },
197 };
198
199 static struct platform_driver pxa_ssp_driver = {
200 .probe = pxa_ssp_probe,
201 .remove = __devexit_p(pxa_ssp_remove),
202 .driver = {
203 .owner = THIS_MODULE,
204 .name = "pxa2xx-ssp",
205 },
206 .id_table = ssp_id_table,
207 };
208
pxa_ssp_init(void)209 static int __init pxa_ssp_init(void)
210 {
211 return platform_driver_register(&pxa_ssp_driver);
212 }
213
pxa_ssp_exit(void)214 static void __exit pxa_ssp_exit(void)
215 {
216 platform_driver_unregister(&pxa_ssp_driver);
217 }
218
219 arch_initcall(pxa_ssp_init);
220 module_exit(pxa_ssp_exit);
221
222 MODULE_DESCRIPTION("PXA SSP driver");
223 MODULE_AUTHOR("Liam Girdwood");
224 MODULE_LICENSE("GPL");
225