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eb1f2930 HCE |
1 | /* |
2 | * Atmel SSC driver | |
3 | * | |
4 | * Copyright (C) 2007 Atmel Corporation | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 as | |
8 | * published by the Free Software Foundation. | |
9 | */ | |
10 | ||
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> | |
eb1f2930 HCE |
16 | #include <linux/spinlock.h> |
17 | #include <linux/atmel-ssc.h> | |
5a0e3ad6 | 18 | #include <linux/slab.h> |
eb12a679 | 19 | #include <linux/module.h> |
eb1f2930 | 20 | |
099343c6 | 21 | #include <linux/of.h> |
ea03c815 | 22 | #include <linux/pinctrl/consumer.h> |
099343c6 | 23 | |
eb1f2930 HCE |
24 | /* Serialize access to ssc_list and user count */ |
25 | static DEFINE_SPINLOCK(user_lock); | |
26 | static LIST_HEAD(ssc_list); | |
27 | ||
28 | struct 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) { | |
099343c6 BS |
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) { | |
eb1f2930 HCE |
42 | ssc_valid = 1; |
43 | break; | |
44 | } | |
45 | } | |
46 | ||
47 | if (!ssc_valid) { | |
48 | spin_unlock(&user_lock); | |
dfecb716 | 49 | pr_err("ssc: ssc%d platform device is missing\n", ssc_num); |
eb1f2930 HCE |
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 | } | |
65 | EXPORT_SYMBOL(ssc_request); | |
66 | ||
67 | void 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 | } | |
78 | EXPORT_SYMBOL(ssc_free); | |
79 | ||
636036d2 BS |
80 | static struct atmel_ssc_platform_data at91rm9200_config = { |
81 | .use_dma = 0, | |
82 | }; | |
83 | ||
84 | static struct atmel_ssc_platform_data at91sam9g45_config = { | |
85 | .use_dma = 1, | |
86 | }; | |
87 | ||
88 | static 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 | /* sentinel */ | |
97 | } | |
98 | }; | |
99 | ||
099343c6 BS |
100 | #ifdef CONFIG_OF |
101 | static 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 | /* sentinel */ | |
110 | } | |
111 | }; | |
112 | MODULE_DEVICE_TABLE(of, atmel_ssc_dt_ids); | |
113 | #endif | |
114 | ||
115 | static 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 | ||
5c86ac69 | 130 | static int ssc_probe(struct platform_device *pdev) |
eb1f2930 | 131 | { |
eb1f2930 HCE |
132 | struct resource *regs; |
133 | struct ssc_device *ssc; | |
099343c6 | 134 | const struct atmel_ssc_platform_data *plat_dat; |
ea03c815 BS |
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 | } | |
eb1f2930 | 142 | |
2e4de7b3 | 143 | ssc = devm_kzalloc(&pdev->dev, sizeof(struct ssc_device), GFP_KERNEL); |
eb1f2930 HCE |
144 | if (!ssc) { |
145 | dev_dbg(&pdev->dev, "out of memory\n"); | |
2e4de7b3 | 146 | return -ENOMEM; |
eb1f2930 HCE |
147 | } |
148 | ||
2e4de7b3 | 149 | ssc->pdev = pdev; |
099343c6 BS |
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; | |
2e4de7b3 | 155 | |
eb1f2930 | 156 | regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
1684789f TR |
157 | ssc->regs = devm_ioremap_resource(&pdev->dev, regs); |
158 | if (IS_ERR(ssc->regs)) | |
159 | return PTR_ERR(ssc->regs); | |
2e4de7b3 | 160 | |
31974361 NF |
161 | ssc->phybase = regs->start; |
162 | ||
2e4de7b3 BS |
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; | |
eb1f2930 HCE |
167 | } |
168 | ||
169 | /* disable all interrupts */ | |
170 | clk_enable(ssc->clk); | |
f4319ff2 | 171 | ssc_writel(ssc->regs, IDR, -1); |
eb1f2930 HCE |
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"); | |
2e4de7b3 | 178 | return -ENXIO; |
eb1f2930 HCE |
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 | ||
2e4de7b3 | 190 | return 0; |
eb1f2930 HCE |
191 | } |
192 | ||
486a5c28 | 193 | static int ssc_remove(struct platform_device *pdev) |
eb1f2930 HCE |
194 | { |
195 | struct ssc_device *ssc = platform_get_drvdata(pdev); | |
196 | ||
197 | spin_lock(&user_lock); | |
eb1f2930 | 198 | list_del(&ssc->list); |
eb1f2930 HCE |
199 | spin_unlock(&user_lock); |
200 | ||
201 | return 0; | |
202 | } | |
203 | ||
204 | static struct platform_driver ssc_driver = { | |
eb1f2930 HCE |
205 | .driver = { |
206 | .name = "ssc", | |
d6c23850 | 207 | .owner = THIS_MODULE, |
099343c6 | 208 | .of_match_table = of_match_ptr(atmel_ssc_dt_ids), |
eb1f2930 | 209 | }, |
636036d2 | 210 | .id_table = atmel_ssc_devtypes, |
5c86ac69 | 211 | .probe = ssc_probe, |
046e7d68 | 212 | .remove = ssc_remove, |
eb1f2930 | 213 | }; |
5c86ac69 | 214 | module_platform_driver(ssc_driver); |
eb1f2930 HCE |
215 | |
216 | MODULE_AUTHOR("Hans-Christian Egtvedt <hcegtvedt@atmel.com>"); | |
217 | MODULE_DESCRIPTION("SSC driver for Atmel AVR32 and AT91"); | |
218 | MODULE_LICENSE("GPL"); | |
d6c23850 | 219 | MODULE_ALIAS("platform:ssc"); |