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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 BS |
21 | #include <linux/of.h> |
22 | ||
eb1f2930 HCE |
23 | /* Serialize access to ssc_list and user count */ |
24 | static DEFINE_SPINLOCK(user_lock); | |
25 | static LIST_HEAD(ssc_list); | |
26 | ||
27 | struct 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) { | |
099343c6 BS |
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) { | |
eb1f2930 HCE |
41 | ssc_valid = 1; |
42 | break; | |
43 | } | |
44 | } | |
45 | ||
46 | if (!ssc_valid) { | |
47 | spin_unlock(&user_lock); | |
dfecb716 | 48 | pr_err("ssc: ssc%d platform device is missing\n", ssc_num); |
eb1f2930 HCE |
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 | ||
6f0d9479 | 60 | clk_prepare_enable(ssc->clk); |
eb1f2930 HCE |
61 | |
62 | return ssc; | |
63 | } | |
64 | EXPORT_SYMBOL(ssc_request); | |
65 | ||
66 | void ssc_free(struct ssc_device *ssc) | |
67 | { | |
9a9b1c61 BB |
68 | bool disable_clk = true; |
69 | ||
eb1f2930 | 70 | spin_lock(&user_lock); |
9a9b1c61 | 71 | if (ssc->user) |
eb1f2930 | 72 | ssc->user--; |
9a9b1c61 BB |
73 | else { |
74 | disable_clk = false; | |
eb1f2930 HCE |
75 | dev_dbg(&ssc->pdev->dev, "device already free\n"); |
76 | } | |
77 | spin_unlock(&user_lock); | |
9a9b1c61 BB |
78 | |
79 | if (disable_clk) | |
80 | clk_disable_unprepare(ssc->clk); | |
eb1f2930 HCE |
81 | } |
82 | EXPORT_SYMBOL(ssc_free); | |
83 | ||
636036d2 BS |
84 | static struct atmel_ssc_platform_data at91rm9200_config = { |
85 | .use_dma = 0, | |
86 | }; | |
87 | ||
88 | static struct atmel_ssc_platform_data at91sam9g45_config = { | |
89 | .use_dma = 1, | |
90 | }; | |
91 | ||
92 | static const struct platform_device_id atmel_ssc_devtypes[] = { | |
93 | { | |
94 | .name = "at91rm9200_ssc", | |
95 | .driver_data = (unsigned long) &at91rm9200_config, | |
96 | }, { | |
97 | .name = "at91sam9g45_ssc", | |
98 | .driver_data = (unsigned long) &at91sam9g45_config, | |
99 | }, { | |
100 | /* sentinel */ | |
101 | } | |
102 | }; | |
103 | ||
099343c6 BS |
104 | #ifdef CONFIG_OF |
105 | static const struct of_device_id atmel_ssc_dt_ids[] = { | |
106 | { | |
107 | .compatible = "atmel,at91rm9200-ssc", | |
108 | .data = &at91rm9200_config, | |
109 | }, { | |
110 | .compatible = "atmel,at91sam9g45-ssc", | |
111 | .data = &at91sam9g45_config, | |
112 | }, { | |
113 | /* sentinel */ | |
114 | } | |
115 | }; | |
116 | MODULE_DEVICE_TABLE(of, atmel_ssc_dt_ids); | |
117 | #endif | |
118 | ||
119 | static inline const struct atmel_ssc_platform_data * __init | |
120 | atmel_ssc_get_driver_data(struct platform_device *pdev) | |
121 | { | |
122 | if (pdev->dev.of_node) { | |
123 | const struct of_device_id *match; | |
124 | match = of_match_node(atmel_ssc_dt_ids, pdev->dev.of_node); | |
125 | if (match == NULL) | |
126 | return NULL; | |
127 | return match->data; | |
128 | } | |
129 | ||
130 | return (struct atmel_ssc_platform_data *) | |
131 | platform_get_device_id(pdev)->driver_data; | |
132 | } | |
133 | ||
5c86ac69 | 134 | static int ssc_probe(struct platform_device *pdev) |
eb1f2930 | 135 | { |
eb1f2930 HCE |
136 | struct resource *regs; |
137 | struct ssc_device *ssc; | |
099343c6 | 138 | const struct atmel_ssc_platform_data *plat_dat; |
eb1f2930 | 139 | |
2e4de7b3 | 140 | ssc = devm_kzalloc(&pdev->dev, sizeof(struct ssc_device), GFP_KERNEL); |
eb1f2930 HCE |
141 | if (!ssc) { |
142 | dev_dbg(&pdev->dev, "out of memory\n"); | |
2e4de7b3 | 143 | return -ENOMEM; |
eb1f2930 HCE |
144 | } |
145 | ||
2e4de7b3 | 146 | ssc->pdev = pdev; |
099343c6 BS |
147 | |
148 | plat_dat = atmel_ssc_get_driver_data(pdev); | |
149 | if (!plat_dat) | |
150 | return -ENODEV; | |
151 | ssc->pdata = (struct atmel_ssc_platform_data *)plat_dat; | |
2e4de7b3 | 152 | |
eb1f2930 | 153 | regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
1684789f TR |
154 | ssc->regs = devm_ioremap_resource(&pdev->dev, regs); |
155 | if (IS_ERR(ssc->regs)) | |
156 | return PTR_ERR(ssc->regs); | |
2e4de7b3 | 157 | |
31974361 NF |
158 | ssc->phybase = regs->start; |
159 | ||
2e4de7b3 BS |
160 | ssc->clk = devm_clk_get(&pdev->dev, "pclk"); |
161 | if (IS_ERR(ssc->clk)) { | |
162 | dev_dbg(&pdev->dev, "no pclk clock defined\n"); | |
163 | return -ENXIO; | |
eb1f2930 HCE |
164 | } |
165 | ||
166 | /* disable all interrupts */ | |
6f0d9479 | 167 | clk_prepare_enable(ssc->clk); |
f4319ff2 | 168 | ssc_writel(ssc->regs, IDR, -1); |
eb1f2930 | 169 | ssc_readl(ssc->regs, SR); |
6f0d9479 | 170 | clk_disable_unprepare(ssc->clk); |
eb1f2930 HCE |
171 | |
172 | ssc->irq = platform_get_irq(pdev, 0); | |
173 | if (!ssc->irq) { | |
174 | dev_dbg(&pdev->dev, "could not get irq\n"); | |
2e4de7b3 | 175 | return -ENXIO; |
eb1f2930 HCE |
176 | } |
177 | ||
178 | spin_lock(&user_lock); | |
179 | list_add_tail(&ssc->list, &ssc_list); | |
180 | spin_unlock(&user_lock); | |
181 | ||
182 | platform_set_drvdata(pdev, ssc); | |
183 | ||
184 | dev_info(&pdev->dev, "Atmel SSC device at 0x%p (irq %d)\n", | |
185 | ssc->regs, ssc->irq); | |
186 | ||
2e4de7b3 | 187 | return 0; |
eb1f2930 HCE |
188 | } |
189 | ||
486a5c28 | 190 | static int ssc_remove(struct platform_device *pdev) |
eb1f2930 HCE |
191 | { |
192 | struct ssc_device *ssc = platform_get_drvdata(pdev); | |
193 | ||
194 | spin_lock(&user_lock); | |
eb1f2930 | 195 | list_del(&ssc->list); |
eb1f2930 HCE |
196 | spin_unlock(&user_lock); |
197 | ||
198 | return 0; | |
199 | } | |
200 | ||
201 | static struct platform_driver ssc_driver = { | |
eb1f2930 HCE |
202 | .driver = { |
203 | .name = "ssc", | |
d6c23850 | 204 | .owner = THIS_MODULE, |
099343c6 | 205 | .of_match_table = of_match_ptr(atmel_ssc_dt_ids), |
eb1f2930 | 206 | }, |
636036d2 | 207 | .id_table = atmel_ssc_devtypes, |
5c86ac69 | 208 | .probe = ssc_probe, |
046e7d68 | 209 | .remove = ssc_remove, |
eb1f2930 | 210 | }; |
5c86ac69 | 211 | module_platform_driver(ssc_driver); |
eb1f2930 HCE |
212 | |
213 | MODULE_AUTHOR("Hans-Christian Egtvedt <hcegtvedt@atmel.com>"); | |
214 | MODULE_DESCRIPTION("SSC driver for Atmel AVR32 and AT91"); | |
215 | MODULE_LICENSE("GPL"); | |
d6c23850 | 216 | MODULE_ALIAS("platform:ssc"); |