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Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -07001/*
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>
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -070016#include <linux/spinlock.h>
17#include <linux/atmel-ssc.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090018#include <linux/slab.h>
Paul Gortmakereb12a672011-07-03 15:14:56 -040019#include <linux/module.h>
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -070020
Bo Shen099343c2012-11-07 11:41:41 +080021#include <linux/of.h>
22
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -070023/* Serialize access to ssc_list and user count */
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) {
Bo Shen099343c2012-11-07 11:41:41 +080034 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) {
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -070041 ssc_valid = 1;
42 break;
43 }
44 }
45
46 if (!ssc_valid) {
47 spin_unlock(&user_lock);
Hans-Christian Egtvedtdfecb712009-02-04 15:12:17 -080048 pr_err("ssc: ssc%d platform device is missing\n", ssc_num);
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -070049 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
Boris BREZILLON6f0d9472013-06-07 18:26:09 +020060 clk_prepare_enable(ssc->clk);
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -070061
62 return ssc;
63}
64EXPORT_SYMBOL(ssc_request);
65
66void ssc_free(struct ssc_device *ssc)
67{
Boris BREZILLON9a9b1c62013-07-18 09:48:40 +020068 bool disable_clk = true;
69
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -070070 spin_lock(&user_lock);
Boris BREZILLON9a9b1c62013-07-18 09:48:40 +020071 if (ssc->user)
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -070072 ssc->user--;
Boris BREZILLON9a9b1c62013-07-18 09:48:40 +020073 else {
74 disable_clk = false;
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -070075 dev_dbg(&ssc->pdev->dev, "device already free\n");
76 }
77 spin_unlock(&user_lock);
Boris BREZILLON9a9b1c62013-07-18 09:48:40 +020078
79 if (disable_clk)
80 clk_disable_unprepare(ssc->clk);
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -070081}
82EXPORT_SYMBOL(ssc_free);
83
Bo Shen636036d22012-11-06 13:57:51 +080084static struct atmel_ssc_platform_data at91rm9200_config = {
85 .use_dma = 0,
86};
87
88static struct atmel_ssc_platform_data at91sam9g45_config = {
89 .use_dma = 1,
90};
91
92static 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
Bo Shen099343c2012-11-07 11:41:41 +0800104#ifdef CONFIG_OF
105static 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};
116MODULE_DEVICE_TABLE(of, atmel_ssc_dt_ids);
117#endif
118
119static inline const struct atmel_ssc_platform_data * __init
120 atmel_ssc_get_driver_data(struct platform_device *pdev)
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -0700121{
Bo Shen099343c2012-11-07 11:41:41 +0800122 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
Bo Shen5c86ac62012-10-16 11:56:59 +0800134static int ssc_probe(struct platform_device *pdev)
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -0700135{
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -0700136 struct resource *regs;
137 struct ssc_device *ssc;
Bo Shen099343c2012-11-07 11:41:41 +0800138 const struct atmel_ssc_platform_data *plat_dat;
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -0700139
Bo Shen2e4de7b2012-10-16 11:56:58 +0800140 ssc = devm_kzalloc(&pdev->dev, sizeof(struct ssc_device), GFP_KERNEL);
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -0700141 if (!ssc) {
142 dev_dbg(&pdev->dev, "out of memory\n");
Bo Shen2e4de7b2012-10-16 11:56:58 +0800143 return -ENOMEM;
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -0700144 }
145
Bo Shen2e4de7b2012-10-16 11:56:58 +0800146 ssc->pdev = pdev;
Bo Shen099343c2012-11-07 11:41:41 +0800147
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;
Bo Shen2e4de7b2012-10-16 11:56:58 +0800152
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -0700153 regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
Thierry Reding16847892013-01-21 11:09:10 +0100154 ssc->regs = devm_ioremap_resource(&pdev->dev, regs);
155 if (IS_ERR(ssc->regs))
156 return PTR_ERR(ssc->regs);
Bo Shen2e4de7b2012-10-16 11:56:58 +0800157
Nicolas Ferre31974362012-11-20 16:38:17 +0800158 ssc->phybase = regs->start;
159
Bo Shen2e4de7b2012-10-16 11:56:58 +0800160 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;
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -0700164 }
165
166 /* disable all interrupts */
Boris BREZILLON6f0d9472013-06-07 18:26:09 +0200167 clk_prepare_enable(ssc->clk);
Joachim Eastwoodf4319ff2012-12-08 13:46:41 +0100168 ssc_writel(ssc->regs, IDR, -1);
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -0700169 ssc_readl(ssc->regs, SR);
Boris BREZILLON6f0d9472013-06-07 18:26:09 +0200170 clk_disable_unprepare(ssc->clk);
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -0700171
172 ssc->irq = platform_get_irq(pdev, 0);
173 if (!ssc->irq) {
174 dev_dbg(&pdev->dev, "could not get irq\n");
Bo Shen2e4de7b2012-10-16 11:56:58 +0800175 return -ENXIO;
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -0700176 }
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
Bo Shen2e4de7b2012-10-16 11:56:58 +0800187 return 0;
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -0700188}
189
Bill Pemberton486a5c22012-11-19 13:26:02 -0500190static int ssc_remove(struct platform_device *pdev)
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -0700191{
192 struct ssc_device *ssc = platform_get_drvdata(pdev);
193
194 spin_lock(&user_lock);
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -0700195 list_del(&ssc->list);
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -0700196 spin_unlock(&user_lock);
197
198 return 0;
199}
200
201static struct platform_driver ssc_driver = {
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -0700202 .driver = {
203 .name = "ssc",
Kay Sieversd6c23852008-04-15 14:34:33 -0700204 .owner = THIS_MODULE,
Bo Shen099343c2012-11-07 11:41:41 +0800205 .of_match_table = of_match_ptr(atmel_ssc_dt_ids),
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -0700206 },
Bo Shen636036d22012-11-06 13:57:51 +0800207 .id_table = atmel_ssc_devtypes,
Bo Shen5c86ac62012-10-16 11:56:59 +0800208 .probe = ssc_probe,
Linus Torvalds046e7d62012-12-13 11:51:23 -0800209 .remove = ssc_remove,
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -0700210};
Bo Shen5c86ac62012-10-16 11:56:59 +0800211module_platform_driver(ssc_driver);
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -0700212
213MODULE_AUTHOR("Hans-Christian Egtvedt <hcegtvedt@atmel.com>");
214MODULE_DESCRIPTION("SSC driver for Atmel AVR32 and AT91");
215MODULE_LICENSE("GPL");
Kay Sieversd6c23852008-04-15 14:34:33 -0700216MODULE_ALIAS("platform:ssc");