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11#include <linux/platform_device.h>
12#include <linux/list.h>
13#include <linux/clk.h>
14#include <linux/err.h>
15#include <linux/io.h>
16#include <linux/spinlock.h>
17#include <linux/atmel-ssc.h>
18#include <linux/slab.h>
19#include <linux/module.h>
20
21#include <linux/of.h>
22
23
24static DEFINE_SPINLOCK(user_lock);
25static LIST_HEAD(ssc_list);
26
27struct ssc_device *ssc_request(unsigned int ssc_num)
28{
29 int ssc_valid = 0;
30 struct ssc_device *ssc;
31
32 spin_lock(&user_lock);
33 list_for_each_entry(ssc, &ssc_list, list) {
34 if (ssc->pdev->dev.of_node) {
35 if (of_alias_get_id(ssc->pdev->dev.of_node, "ssc")
36 == ssc_num) {
37 ssc_valid = 1;
38 break;
39 }
40 } else if (ssc->pdev->id == ssc_num) {
41 ssc_valid = 1;
42 break;
43 }
44 }
45
46 if (!ssc_valid) {
47 spin_unlock(&user_lock);
48 pr_err("ssc: ssc%d platform device is missing\n", ssc_num);
49 return ERR_PTR(-ENODEV);
50 }
51
52 if (ssc->user) {
53 spin_unlock(&user_lock);
54 dev_dbg(&ssc->pdev->dev, "module busy\n");
55 return ERR_PTR(-EBUSY);
56 }
57 ssc->user++;
58 spin_unlock(&user_lock);
59
60 clk_prepare_enable(ssc->clk);
61
62 return ssc;
63}
64EXPORT_SYMBOL(ssc_request);
65
66void ssc_free(struct ssc_device *ssc)
67{
68 bool disable_clk = true;
69
70 spin_lock(&user_lock);
71 if (ssc->user)
72 ssc->user--;
73 else {
74 disable_clk = false;
75 dev_dbg(&ssc->pdev->dev, "device already free\n");
76 }
77 spin_unlock(&user_lock);
78
79 if (disable_clk)
80 clk_disable_unprepare(ssc->clk);
81}
82EXPORT_SYMBOL(ssc_free);
83
84static struct atmel_ssc_platform_data at91rm9200_config = {
85 .use_dma = 0,
86 .has_fslen_ext = 0,
87};
88
89static struct atmel_ssc_platform_data at91sam9rl_config = {
90 .use_dma = 0,
91 .has_fslen_ext = 1,
92};
93
94static struct atmel_ssc_platform_data at91sam9g45_config = {
95 .use_dma = 1,
96 .has_fslen_ext = 1,
97};
98
99static const struct platform_device_id atmel_ssc_devtypes[] = {
100 {
101 .name = "at91rm9200_ssc",
102 .driver_data = (unsigned long) &at91rm9200_config,
103 }, {
104 .name = "at91sam9rl_ssc",
105 .driver_data = (unsigned long) &at91sam9rl_config,
106 }, {
107 .name = "at91sam9g45_ssc",
108 .driver_data = (unsigned long) &at91sam9g45_config,
109 }, {
110
111 }
112};
113
114#ifdef CONFIG_OF
115static const struct of_device_id atmel_ssc_dt_ids[] = {
116 {
117 .compatible = "atmel,at91rm9200-ssc",
118 .data = &at91rm9200_config,
119 }, {
120 .compatible = "atmel,at91sam9rl-ssc",
121 .data = &at91sam9rl_config,
122 }, {
123 .compatible = "atmel,at91sam9g45-ssc",
124 .data = &at91sam9g45_config,
125 }, {
126
127 }
128};
129MODULE_DEVICE_TABLE(of, atmel_ssc_dt_ids);
130#endif
131
132static inline const struct atmel_ssc_platform_data * __init
133 atmel_ssc_get_driver_data(struct platform_device *pdev)
134{
135 if (pdev->dev.of_node) {
136 const struct of_device_id *match;
137 match = of_match_node(atmel_ssc_dt_ids, pdev->dev.of_node);
138 if (match == NULL)
139 return NULL;
140 return match->data;
141 }
142
143 return (struct atmel_ssc_platform_data *)
144 platform_get_device_id(pdev)->driver_data;
145}
146
147static int ssc_probe(struct platform_device *pdev)
148{
149 struct resource *regs;
150 struct ssc_device *ssc;
151 const struct atmel_ssc_platform_data *plat_dat;
152
153 ssc = devm_kzalloc(&pdev->dev, sizeof(struct ssc_device), GFP_KERNEL);
154 if (!ssc) {
155 dev_dbg(&pdev->dev, "out of memory\n");
156 return -ENOMEM;
157 }
158
159 ssc->pdev = pdev;
160
161 plat_dat = atmel_ssc_get_driver_data(pdev);
162 if (!plat_dat)
163 return -ENODEV;
164 ssc->pdata = (struct atmel_ssc_platform_data *)plat_dat;
165
166 if (pdev->dev.of_node) {
167 struct device_node *np = pdev->dev.of_node;
168 ssc->clk_from_rk_pin =
169 of_property_read_bool(np, "atmel,clk-from-rk-pin");
170 }
171
172 regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
173 ssc->regs = devm_ioremap_resource(&pdev->dev, regs);
174 if (IS_ERR(ssc->regs))
175 return PTR_ERR(ssc->regs);
176
177 ssc->phybase = regs->start;
178
179 ssc->clk = devm_clk_get(&pdev->dev, "pclk");
180 if (IS_ERR(ssc->clk)) {
181 dev_dbg(&pdev->dev, "no pclk clock defined\n");
182 return -ENXIO;
183 }
184
185
186 clk_prepare_enable(ssc->clk);
187 ssc_writel(ssc->regs, IDR, -1);
188 ssc_readl(ssc->regs, SR);
189 clk_disable_unprepare(ssc->clk);
190
191 ssc->irq = platform_get_irq(pdev, 0);
192 if (!ssc->irq) {
193 dev_dbg(&pdev->dev, "could not get irq\n");
194 return -ENXIO;
195 }
196
197 spin_lock(&user_lock);
198 list_add_tail(&ssc->list, &ssc_list);
199 spin_unlock(&user_lock);
200
201 platform_set_drvdata(pdev, ssc);
202
203 dev_info(&pdev->dev, "Atmel SSC device at 0x%p (irq %d)\n",
204 ssc->regs, ssc->irq);
205
206 return 0;
207}
208
209static int ssc_remove(struct platform_device *pdev)
210{
211 struct ssc_device *ssc = platform_get_drvdata(pdev);
212
213 spin_lock(&user_lock);
214 list_del(&ssc->list);
215 spin_unlock(&user_lock);
216
217 return 0;
218}
219
220static struct platform_driver ssc_driver = {
221 .driver = {
222 .name = "ssc",
223 .owner = THIS_MODULE,
224 .of_match_table = of_match_ptr(atmel_ssc_dt_ids),
225 },
226 .id_table = atmel_ssc_devtypes,
227 .probe = ssc_probe,
228 .remove = ssc_remove,
229};
230module_platform_driver(ssc_driver);
231
232MODULE_AUTHOR("Hans-Christian Egtvedt <hcegtvedt@atmel.com>");
233MODULE_DESCRIPTION("SSC driver for Atmel AVR32 and AT91");
234MODULE_LICENSE("GPL");
235MODULE_ALIAS("platform:ssc");
236
