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 { .compatible = "mrvl,lpss-ssp", .data = (void *) LPSS_SSP },
111 { },
112 };
113 MODULE_DEVICE_TABLE(of, pxa_ssp_of_ids);
114 #endif
115
pxa_ssp_probe(struct platform_device * pdev)116 static int pxa_ssp_probe(struct platform_device *pdev)
117 {
118 struct resource *res;
119 struct ssp_device *ssp;
120 struct device *dev = &pdev->dev;
121
122 ssp = devm_kzalloc(dev, sizeof(struct ssp_device), GFP_KERNEL);
123 if (ssp == NULL)
124 return -ENOMEM;
125
126 ssp->pdev = pdev;
127
128 ssp->clk = devm_clk_get(dev, NULL);
129 if (IS_ERR(ssp->clk))
130 return PTR_ERR(ssp->clk);
131
132 if (dev->of_node) {
133 struct of_phandle_args dma_spec;
134 struct device_node *np = dev->of_node;
135 int ret;
136
137 /*
138 * FIXME: we should allocate the DMA channel from this
139 * context and pass the channel down to the ssp users.
140 * For now, we lookup the rx and tx indices manually
141 */
142
143 /* rx */
144 ret = of_parse_phandle_with_args(np, "dmas", "#dma-cells",
145 0, &dma_spec);
146
147 if (ret) {
148 dev_err(dev, "Can't parse dmas property\n");
149 return -ENODEV;
150 }
151 ssp->drcmr_rx = dma_spec.args[0];
152 of_node_put(dma_spec.np);
153
154 /* tx */
155 ret = of_parse_phandle_with_args(np, "dmas", "#dma-cells",
156 1, &dma_spec);
157 if (ret) {
158 dev_err(dev, "Can't parse dmas property\n");
159 return -ENODEV;
160 }
161 ssp->drcmr_tx = dma_spec.args[0];
162 of_node_put(dma_spec.np);
163 } else {
164 res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
165 if (res == NULL) {
166 dev_err(dev, "no SSP RX DRCMR defined\n");
167 return -ENODEV;
168 }
169 ssp->drcmr_rx = res->start;
170
171 res = platform_get_resource(pdev, IORESOURCE_DMA, 1);
172 if (res == NULL) {
173 dev_err(dev, "no SSP TX DRCMR defined\n");
174 return -ENODEV;
175 }
176 ssp->drcmr_tx = res->start;
177 }
178
179 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
180 if (res == NULL) {
181 dev_err(dev, "no memory resource defined\n");
182 return -ENODEV;
183 }
184
185 res = devm_request_mem_region(dev, res->start, resource_size(res),
186 pdev->name);
187 if (res == NULL) {
188 dev_err(dev, "failed to request memory resource\n");
189 return -EBUSY;
190 }
191
192 ssp->phys_base = res->start;
193
194 ssp->mmio_base = devm_ioremap(dev, res->start, resource_size(res));
195 if (ssp->mmio_base == NULL) {
196 dev_err(dev, "failed to ioremap() registers\n");
197 return -ENODEV;
198 }
199
200 ssp->irq = platform_get_irq(pdev, 0);
201 if (ssp->irq < 0) {
202 dev_err(dev, "no IRQ resource defined\n");
203 return -ENODEV;
204 }
205
206 if (dev->of_node) {
207 const struct of_device_id *id =
208 of_match_device(of_match_ptr(pxa_ssp_of_ids), dev);
209 ssp->type = (int) id->data;
210 } else {
211 const struct platform_device_id *id =
212 platform_get_device_id(pdev);
213 ssp->type = (int) id->driver_data;
214
215 /* PXA2xx/3xx SSP ports starts from 1 and the internal pdev->id
216 * starts from 0, do a translation here
217 */
218 ssp->port_id = pdev->id + 1;
219 }
220
221 ssp->use_count = 0;
222 ssp->of_node = dev->of_node;
223
224 mutex_lock(&ssp_lock);
225 list_add(&ssp->node, &ssp_list);
226 mutex_unlock(&ssp_lock);
227
228 platform_set_drvdata(pdev, ssp);
229
230 return 0;
231 }
232
pxa_ssp_remove(struct platform_device * pdev)233 static int pxa_ssp_remove(struct platform_device *pdev)
234 {
235 struct resource *res;
236 struct ssp_device *ssp;
237
238 ssp = platform_get_drvdata(pdev);
239 if (ssp == NULL)
240 return -ENODEV;
241
242 iounmap(ssp->mmio_base);
243
244 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
245 release_mem_region(res->start, resource_size(res));
246
247 clk_put(ssp->clk);
248
249 mutex_lock(&ssp_lock);
250 list_del(&ssp->node);
251 mutex_unlock(&ssp_lock);
252
253 kfree(ssp);
254 return 0;
255 }
256
257 static const struct platform_device_id ssp_id_table[] = {
258 { "pxa25x-ssp", PXA25x_SSP },
259 { "pxa25x-nssp", PXA25x_NSSP },
260 { "pxa27x-ssp", PXA27x_SSP },
261 { "pxa3xx-ssp", PXA3xx_SSP },
262 { "pxa168-ssp", PXA168_SSP },
263 { "pxa910-ssp", PXA910_SSP },
264 { },
265 };
266
267 static struct platform_driver pxa_ssp_driver = {
268 .probe = pxa_ssp_probe,
269 .remove = pxa_ssp_remove,
270 .driver = {
271 .owner = THIS_MODULE,
272 .name = "pxa2xx-ssp",
273 .of_match_table = of_match_ptr(pxa_ssp_of_ids),
274 },
275 .id_table = ssp_id_table,
276 };
277
pxa_ssp_init(void)278 static int __init pxa_ssp_init(void)
279 {
280 return platform_driver_register(&pxa_ssp_driver);
281 }
282
pxa_ssp_exit(void)283 static void __exit pxa_ssp_exit(void)
284 {
285 platform_driver_unregister(&pxa_ssp_driver);
286 }
287
288 arch_initcall(pxa_ssp_init);
289 module_exit(pxa_ssp_exit);
290
291 MODULE_DESCRIPTION("PXA SSP driver");
292 MODULE_AUTHOR("Liam Girdwood");
293 MODULE_LICENSE("GPL");
294