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