4 * Copyright (C) 2007 Atmel Corporation
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.
11 #include <linux/platform_device.h>
12 #include <linux/list.h>
13 #include <linux/clk.h>
14 #include <linux/err.h>
16 #include <linux/spinlock.h>
17 #include <linux/atmel-ssc.h>
18 #include <linux/slab.h>
19 #include <linux/module.h>
23 /* Serialize access to ssc_list and user count */
24 static DEFINE_SPINLOCK(user_lock
);
25 static LIST_HEAD(ssc_list
);
27 struct ssc_device
*ssc_request(unsigned int ssc_num
)
30 struct ssc_device
*ssc
;
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")
40 } else if (ssc
->pdev
->id
== ssc_num
) {
47 spin_unlock(&user_lock
);
48 pr_err("ssc: ssc%d platform device is missing\n", ssc_num
);
49 return ERR_PTR(-ENODEV
);
53 spin_unlock(&user_lock
);
54 dev_dbg(&ssc
->pdev
->dev
, "module busy\n");
55 return ERR_PTR(-EBUSY
);
58 spin_unlock(&user_lock
);
64 EXPORT_SYMBOL(ssc_request
);
66 void ssc_free(struct ssc_device
*ssc
)
68 spin_lock(&user_lock
);
71 clk_disable(ssc
->clk
);
73 dev_dbg(&ssc
->pdev
->dev
, "device already free\n");
75 spin_unlock(&user_lock
);
77 EXPORT_SYMBOL(ssc_free
);
79 static struct atmel_ssc_platform_data at91rm9200_config
= {
83 static struct atmel_ssc_platform_data at91sam9g45_config
= {
87 static const struct platform_device_id atmel_ssc_devtypes
[] = {
89 .name
= "at91rm9200_ssc",
90 .driver_data
= (unsigned long) &at91rm9200_config
,
92 .name
= "at91sam9g45_ssc",
93 .driver_data
= (unsigned long) &at91sam9g45_config
,
100 static const struct of_device_id atmel_ssc_dt_ids
[] = {
102 .compatible
= "atmel,at91rm9200-ssc",
103 .data
= &at91rm9200_config
,
105 .compatible
= "atmel,at91sam9g45-ssc",
106 .data
= &at91sam9g45_config
,
111 MODULE_DEVICE_TABLE(of
, atmel_ssc_dt_ids
);
114 static inline const struct atmel_ssc_platform_data
* __init
115 atmel_ssc_get_driver_data(struct platform_device
*pdev
)
117 if (pdev
->dev
.of_node
) {
118 const struct of_device_id
*match
;
119 match
= of_match_node(atmel_ssc_dt_ids
, pdev
->dev
.of_node
);
125 return (struct atmel_ssc_platform_data
*)
126 platform_get_device_id(pdev
)->driver_data
;
129 static int ssc_probe(struct platform_device
*pdev
)
131 struct resource
*regs
;
132 struct ssc_device
*ssc
;
133 const struct atmel_ssc_platform_data
*plat_dat
;
135 ssc
= devm_kzalloc(&pdev
->dev
, sizeof(struct ssc_device
), GFP_KERNEL
);
137 dev_dbg(&pdev
->dev
, "out of memory\n");
143 plat_dat
= atmel_ssc_get_driver_data(pdev
);
146 ssc
->pdata
= (struct atmel_ssc_platform_data
*)plat_dat
;
148 regs
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
150 dev_dbg(&pdev
->dev
, "no mmio resource defined\n");
154 ssc
->regs
= devm_request_and_ioremap(&pdev
->dev
, regs
);
156 dev_dbg(&pdev
->dev
, "ioremap failed\n");
160 ssc
->phybase
= regs
->start
;
162 ssc
->clk
= devm_clk_get(&pdev
->dev
, "pclk");
163 if (IS_ERR(ssc
->clk
)) {
164 dev_dbg(&pdev
->dev
, "no pclk clock defined\n");
168 /* disable all interrupts */
169 clk_enable(ssc
->clk
);
170 ssc_writel(ssc
->regs
, IDR
, ~0UL);
171 ssc_readl(ssc
->regs
, SR
);
172 clk_disable(ssc
->clk
);
174 ssc
->irq
= platform_get_irq(pdev
, 0);
176 dev_dbg(&pdev
->dev
, "could not get irq\n");
180 spin_lock(&user_lock
);
181 list_add_tail(&ssc
->list
, &ssc_list
);
182 spin_unlock(&user_lock
);
184 platform_set_drvdata(pdev
, ssc
);
186 dev_info(&pdev
->dev
, "Atmel SSC device at 0x%p (irq %d)\n",
187 ssc
->regs
, ssc
->irq
);
192 static int ssc_remove(struct platform_device
*pdev
)
194 struct ssc_device
*ssc
= platform_get_drvdata(pdev
);
196 spin_lock(&user_lock
);
197 list_del(&ssc
->list
);
198 spin_unlock(&user_lock
);
203 static struct platform_driver ssc_driver
= {
206 .owner
= THIS_MODULE
,
207 .of_match_table
= of_match_ptr(atmel_ssc_dt_ids
),
209 .id_table
= atmel_ssc_devtypes
,
211 .remove
= ssc_remove
,
213 module_platform_driver(ssc_driver
);
215 MODULE_AUTHOR("Hans-Christian Egtvedt <hcegtvedt@atmel.com>");
216 MODULE_DESCRIPTION("SSC driver for Atmel AVR32 and AT91");
217 MODULE_LICENSE("GPL");
218 MODULE_ALIAS("platform:ssc");