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 #include <mach/hardware.h>
38
39 static DEFINE_MUTEX(ssp_lock);
40 static LIST_HEAD(ssp_list);
41
pxa_ssp_request(int port,const char * label)42 struct ssp_device *pxa_ssp_request(int port, const char *label)
43 {
44 struct ssp_device *ssp = NULL;
45
46 mutex_lock(&ssp_lock);
47
48 list_for_each_entry(ssp, &ssp_list, node) {
49 if (ssp->port_id == port && ssp->use_count == 0) {
50 ssp->use_count++;
51 ssp->label = label;
52 break;
53 }
54 }
55
56 mutex_unlock(&ssp_lock);
57
58 if (&ssp->node == &ssp_list)
59 return NULL;
60
61 return ssp;
62 }
63 EXPORT_SYMBOL(pxa_ssp_request);
64
pxa_ssp_request_of(const struct device_node * of_node,const char * label)65 struct ssp_device *pxa_ssp_request_of(const struct device_node *of_node,
66 const char *label)
67 {
68 struct ssp_device *ssp = NULL;
69
70 mutex_lock(&ssp_lock);
71
72 list_for_each_entry(ssp, &ssp_list, node) {
73 if (ssp->of_node == of_node && ssp->use_count == 0) {
74 ssp->use_count++;
75 ssp->label = label;
76 break;
77 }
78 }
79
80 mutex_unlock(&ssp_lock);
81
82 if (&ssp->node == &ssp_list)
83 return NULL;
84
85 return ssp;
86 }
87 EXPORT_SYMBOL(pxa_ssp_request_of);
88
pxa_ssp_free(struct ssp_device * ssp)89 void pxa_ssp_free(struct ssp_device *ssp)
90 {
91 mutex_lock(&ssp_lock);
92 if (ssp->use_count) {
93 ssp->use_count--;
94 ssp->label = NULL;
95 } else
96 dev_err(&ssp->pdev->dev, "device already free\n");
97 mutex_unlock(&ssp_lock);
98 }
99 EXPORT_SYMBOL(pxa_ssp_free);
100
101 #ifdef CONFIG_OF
102 static const struct of_device_id pxa_ssp_of_ids[] = {
103 { .compatible = "mrvl,pxa25x-ssp", .data = (void *) PXA25x_SSP },
104 { .compatible = "mvrl,pxa25x-nssp", .data = (void *) PXA25x_NSSP },
105 { .compatible = "mrvl,pxa27x-ssp", .data = (void *) PXA27x_SSP },
106 { .compatible = "mrvl,pxa3xx-ssp", .data = (void *) PXA3xx_SSP },
107 { .compatible = "mvrl,pxa168-ssp", .data = (void *) PXA168_SSP },
108 { .compatible = "mrvl,pxa910-ssp", .data = (void *) PXA910_SSP },
109 { .compatible = "mrvl,ce4100-ssp", .data = (void *) CE4100_SSP },
110 { },
111 };
112 MODULE_DEVICE_TABLE(of, pxa_ssp_of_ids);
113 #endif
114
pxa_ssp_probe(struct platform_device * pdev)115 static int pxa_ssp_probe(struct platform_device *pdev)
116 {
117 struct resource *res;
118 struct ssp_device *ssp;
119 struct device *dev = &pdev->dev;
120
121 ssp = devm_kzalloc(dev, sizeof(struct ssp_device), GFP_KERNEL);
122 if (ssp == NULL)
123 return -ENOMEM;
124
125 ssp->pdev = pdev;
126
127 ssp->clk = devm_clk_get(dev, NULL);
128 if (IS_ERR(ssp->clk))
129 return PTR_ERR(ssp->clk);
130
131 if (dev->of_node) {
132 struct of_phandle_args dma_spec;
133 struct device_node *np = dev->of_node;
134 int ret;
135
136 /*
137 * FIXME: we should allocate the DMA channel from this
138 * context and pass the channel down to the ssp users.
139 * For now, we lookup the rx and tx indices manually
140 */
141
142 /* rx */
143 ret = of_parse_phandle_with_args(np, "dmas", "#dma-cells",
144 0, &dma_spec);
145
146 if (ret) {
147 dev_err(dev, "Can't parse dmas property\n");
148 return -ENODEV;
149 }
150 ssp->drcmr_rx = dma_spec.args[0];
151 of_node_put(dma_spec.np);
152
153 /* tx */
154 ret = of_parse_phandle_with_args(np, "dmas", "#dma-cells",
155 1, &dma_spec);
156 if (ret) {
157 dev_err(dev, "Can't parse dmas property\n");
158 return -ENODEV;
159 }
160 ssp->drcmr_tx = dma_spec.args[0];
161 of_node_put(dma_spec.np);
162 } else {
163 res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
164 if (res == NULL) {
165 dev_err(dev, "no SSP RX DRCMR defined\n");
166 return -ENODEV;
167 }
168 ssp->drcmr_rx = res->start;
169
170 res = platform_get_resource(pdev, IORESOURCE_DMA, 1);
171 if (res == NULL) {
172 dev_err(dev, "no SSP TX DRCMR defined\n");
173 return -ENODEV;
174 }
175 ssp->drcmr_tx = res->start;
176 }
177
178 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
179 if (res == NULL) {
180 dev_err(dev, "no memory resource defined\n");
181 return -ENODEV;
182 }
183
184 res = devm_request_mem_region(dev, res->start, resource_size(res),
185 pdev->name);
186 if (res == NULL) {
187 dev_err(dev, "failed to request memory resource\n");
188 return -EBUSY;
189 }
190
191 ssp->phys_base = res->start;
192
193 ssp->mmio_base = devm_ioremap(dev, res->start, resource_size(res));
194 if (ssp->mmio_base == NULL) {
195 dev_err(dev, "failed to ioremap() registers\n");
196 return -ENODEV;
197 }
198
199 ssp->irq = platform_get_irq(pdev, 0);
200 if (ssp->irq < 0) {
201 dev_err(dev, "no IRQ resource defined\n");
202 return -ENODEV;
203 }
204
205 if (dev->of_node) {
206 const struct of_device_id *id =
207 of_match_device(of_match_ptr(pxa_ssp_of_ids), dev);
208 ssp->type = (int) id->data;
209 } else {
210 const struct platform_device_id *id =
211 platform_get_device_id(pdev);
212 ssp->type = (int) id->driver_data;
213
214 /* PXA2xx/3xx SSP ports starts from 1 and the internal pdev->id
215 * starts from 0, do a translation here
216 */
217 ssp->port_id = pdev->id + 1;
218 }
219
220 ssp->use_count = 0;
221 ssp->of_node = dev->of_node;
222
223 mutex_lock(&ssp_lock);
224 list_add(&ssp->node, &ssp_list);
225 mutex_unlock(&ssp_lock);
226
227 platform_set_drvdata(pdev, ssp);
228
229 return 0;
230 }
231
pxa_ssp_remove(struct platform_device * pdev)232 static int pxa_ssp_remove(struct platform_device *pdev)
233 {
234 struct resource *res;
235 struct ssp_device *ssp;
236
237 ssp = platform_get_drvdata(pdev);
238 if (ssp == NULL)
239 return -ENODEV;
240
241 iounmap(ssp->mmio_base);
242
243 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
244 release_mem_region(res->start, resource_size(res));
245
246 clk_put(ssp->clk);
247
248 mutex_lock(&ssp_lock);
249 list_del(&ssp->node);
250 mutex_unlock(&ssp_lock);
251
252 kfree(ssp);
253 return 0;
254 }
255
256 static const struct platform_device_id ssp_id_table[] = {
257 { "pxa25x-ssp", PXA25x_SSP },
258 { "pxa25x-nssp", PXA25x_NSSP },
259 { "pxa27x-ssp", PXA27x_SSP },
260 { "pxa3xx-ssp", PXA3xx_SSP },
261 { "pxa168-ssp", PXA168_SSP },
262 { "pxa910-ssp", PXA910_SSP },
263 { },
264 };
265
266 static struct platform_driver pxa_ssp_driver = {
267 .probe = pxa_ssp_probe,
268 .remove = pxa_ssp_remove,
269 .driver = {
270 .name = "pxa2xx-ssp",
271 .of_match_table = of_match_ptr(pxa_ssp_of_ids),
272 },
273 .id_table = ssp_id_table,
274 };
275
pxa_ssp_init(void)276 static int __init pxa_ssp_init(void)
277 {
278 return platform_driver_register(&pxa_ssp_driver);
279 }
280
pxa_ssp_exit(void)281 static void __exit pxa_ssp_exit(void)
282 {
283 platform_driver_unregister(&pxa_ssp_driver);
284 }
285
286 arch_initcall(pxa_ssp_init);
287 module_exit(pxa_ssp_exit);
288
289 MODULE_DESCRIPTION("PXA SSP driver");
290 MODULE_AUTHOR("Liam Girdwood");
291 MODULE_LICENSE("GPL");
292