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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>
Bo Shenea03c812013-01-11 15:08:31 +010022#include <linux/pinctrl/consumer.h>
Bo Shen099343c2012-11-07 11:41:41 +080023
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -070024/* Serialize access to ssc_list and user count */
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) {
Bo Shen099343c2012-11-07 11:41:41 +080035 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) {
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -070042 ssc_valid = 1;
43 break;
44 }
45 }
46
47 if (!ssc_valid) {
48 spin_unlock(&user_lock);
Hans-Christian Egtvedtdfecb712009-02-04 15:12:17 -080049 pr_err("ssc: ssc%d platform device is missing\n", ssc_num);
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -070050 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
Bo Shen636036d22012-11-06 13:57:51 +080080static 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 /* sentinel */
97 }
98};
99
Bo Shen099343c2012-11-07 11:41:41 +0800100#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 /* sentinel */
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)
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -0700117{
Bo Shen099343c2012-11-07 11:41:41 +0800118 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
Bo Shen5c86ac62012-10-16 11:56:59 +0800130static int ssc_probe(struct platform_device *pdev)
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -0700131{
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -0700132 struct resource *regs;
133 struct ssc_device *ssc;
Bo Shen099343c2012-11-07 11:41:41 +0800134 const struct atmel_ssc_platform_data *plat_dat;
Bo Shenea03c812013-01-11 15:08:31 +0100135 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 }
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -0700142
Bo Shen2e4de7b2012-10-16 11:56:58 +0800143 ssc = devm_kzalloc(&pdev->dev, sizeof(struct ssc_device), GFP_KERNEL);
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -0700144 if (!ssc) {
145 dev_dbg(&pdev->dev, "out of memory\n");
Bo Shen2e4de7b2012-10-16 11:56:58 +0800146 return -ENOMEM;
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -0700147 }
148
Bo Shen2e4de7b2012-10-16 11:56:58 +0800149 ssc->pdev = pdev;
Bo Shen099343c2012-11-07 11:41:41 +0800150
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;
Bo Shen2e4de7b2012-10-16 11:56:58 +0800155
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -0700156 regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
157 if (!regs) {
158 dev_dbg(&pdev->dev, "no mmio resource defined\n");
Bo Shen2e4de7b2012-10-16 11:56:58 +0800159 return -ENXIO;
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -0700160 }
161
Thierry Reding16847892013-01-21 11:09:10 +0100162 ssc->regs = devm_ioremap_resource(&pdev->dev, regs);
163 if (IS_ERR(ssc->regs))
164 return PTR_ERR(ssc->regs);
Bo Shen2e4de7b2012-10-16 11:56:58 +0800165
Nicolas Ferre31974362012-11-20 16:38:17 +0800166 ssc->phybase = regs->start;
167
Bo Shen2e4de7b2012-10-16 11:56:58 +0800168 ssc->clk = devm_clk_get(&pdev->dev, "pclk");
169 if (IS_ERR(ssc->clk)) {
170 dev_dbg(&pdev->dev, "no pclk clock defined\n");
171 return -ENXIO;
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -0700172 }
173
174 /* disable all interrupts */
175 clk_enable(ssc->clk);
Joachim Eastwoodf4319ff2012-12-08 13:46:41 +0100176 ssc_writel(ssc->regs, IDR, -1);
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -0700177 ssc_readl(ssc->regs, SR);
178 clk_disable(ssc->clk);
179
180 ssc->irq = platform_get_irq(pdev, 0);
181 if (!ssc->irq) {
182 dev_dbg(&pdev->dev, "could not get irq\n");
Bo Shen2e4de7b2012-10-16 11:56:58 +0800183 return -ENXIO;
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -0700184 }
185
186 spin_lock(&user_lock);
187 list_add_tail(&ssc->list, &ssc_list);
188 spin_unlock(&user_lock);
189
190 platform_set_drvdata(pdev, ssc);
191
192 dev_info(&pdev->dev, "Atmel SSC device at 0x%p (irq %d)\n",
193 ssc->regs, ssc->irq);
194
Bo Shen2e4de7b2012-10-16 11:56:58 +0800195 return 0;
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -0700196}
197
Bill Pemberton486a5c22012-11-19 13:26:02 -0500198static int ssc_remove(struct platform_device *pdev)
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -0700199{
200 struct ssc_device *ssc = platform_get_drvdata(pdev);
201
202 spin_lock(&user_lock);
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -0700203 list_del(&ssc->list);
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -0700204 spin_unlock(&user_lock);
205
206 return 0;
207}
208
209static struct platform_driver ssc_driver = {
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -0700210 .driver = {
211 .name = "ssc",
Kay Sieversd6c23852008-04-15 14:34:33 -0700212 .owner = THIS_MODULE,
Bo Shen099343c2012-11-07 11:41:41 +0800213 .of_match_table = of_match_ptr(atmel_ssc_dt_ids),
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -0700214 },
Bo Shen636036d22012-11-06 13:57:51 +0800215 .id_table = atmel_ssc_devtypes,
Bo Shen5c86ac62012-10-16 11:56:59 +0800216 .probe = ssc_probe,
Linus Torvalds046e7d62012-12-13 11:51:23 -0800217 .remove = ssc_remove,
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -0700218};
Bo Shen5c86ac62012-10-16 11:56:59 +0800219module_platform_driver(ssc_driver);
Hans-Christian Egtvedteb1f2932007-10-16 23:26:11 -0700220
221MODULE_AUTHOR("Hans-Christian Egtvedt <hcegtvedt@atmel.com>");
222MODULE_DESCRIPTION("SSC driver for Atmel AVR32 and AT91");
223MODULE_LICENSE("GPL");
Kay Sieversd6c23852008-04-15 14:34:33 -0700224MODULE_ALIAS("platform:ssc");