1 files changed, 174 insertions, 0 deletions

diff --git a/drivers/misc/atmel-ssc.c b/drivers/misc/atmel-ssc.c
new file mode 100644
index 000000000000..058ccac700d0
--- /dev/null
+++ b/drivers/misc/atmel-ssc.c
@@ -0,0 +1,174 @@
+/*
+ * Atmel SSC driver
+ *
+ * Copyright (C) 2007 Atmel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/platform_device.h>
+#include <linux/list.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/atmel-ssc.h>
+
+/* Serialize access to ssc_list and user count */
+static DEFINE_SPINLOCK(user_lock);
+static LIST_HEAD(ssc_list);
+
+struct ssc_device *ssc_request(unsigned int ssc_num)
+{
+	int ssc_valid = 0;
+	struct ssc_device *ssc;
+
+	spin_lock(&user_lock);
+	list_for_each_entry(ssc, &ssc_list, list) {
+		if (ssc->pdev->id == ssc_num) {
+			ssc_valid = 1;
+			break;
+		}
+	}
+
+	if (!ssc_valid) {
+		spin_unlock(&user_lock);
+		dev_dbg(&ssc->pdev->dev, "could not find requested device\n");
+		return ERR_PTR(-ENODEV);
+	}
+
+	if (ssc->user) {
+		spin_unlock(&user_lock);
+		dev_dbg(&ssc->pdev->dev, "module busy\n");
+		return ERR_PTR(-EBUSY);
+	}
+	ssc->user++;
+	spin_unlock(&user_lock);
+
+	clk_enable(ssc->clk);
+
+	return ssc;
+}
+EXPORT_SYMBOL(ssc_request);
+
+void ssc_free(struct ssc_device *ssc)
+{
+	spin_lock(&user_lock);
+	if (ssc->user) {
+		ssc->user--;
+		clk_disable(ssc->clk);
+	} else {
+		dev_dbg(&ssc->pdev->dev, "device already free\n");
+	}
+	spin_unlock(&user_lock);
+}
+EXPORT_SYMBOL(ssc_free);
+
+static int __init ssc_probe(struct platform_device *pdev)
+{
+	int retval = 0;
+	struct resource *regs;
+	struct ssc_device *ssc;
+
+	ssc = kzalloc(sizeof(struct ssc_device), GFP_KERNEL);
+	if (!ssc) {
+		dev_dbg(&pdev->dev, "out of memory\n");
+		retval = -ENOMEM;
+		goto out;
+	}
+
+	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!regs) {
+		dev_dbg(&pdev->dev, "no mmio resource defined\n");
+		retval = -ENXIO;
+		goto out_free;
+	}
+
+	ssc->clk = clk_get(&pdev->dev, "pclk");
+	if (IS_ERR(ssc->clk)) {
+		dev_dbg(&pdev->dev, "no pclk clock defined\n");
+		retval = -ENXIO;
+		goto out_free;
+	}
+
+	ssc->pdev = pdev;
+	ssc->regs = ioremap(regs->start, regs->end - regs->start + 1);
+	if (!ssc->regs) {
+		dev_dbg(&pdev->dev, "ioremap failed\n");
+		retval = -EINVAL;
+		goto out_clk;
+	}
+
+	/* disable all interrupts */
+	clk_enable(ssc->clk);
+	ssc_writel(ssc->regs, IDR, ~0UL);
+	ssc_readl(ssc->regs, SR);
+	clk_disable(ssc->clk);
+
+	ssc->irq = platform_get_irq(pdev, 0);
+	if (!ssc->irq) {
+		dev_dbg(&pdev->dev, "could not get irq\n");
+		retval = -ENXIO;
+		goto out_unmap;
+	}
+
+	spin_lock(&user_lock);
+	list_add_tail(&ssc->list, &ssc_list);
+	spin_unlock(&user_lock);
+
+	platform_set_drvdata(pdev, ssc);
+
+	dev_info(&pdev->dev, "Atmel SSC device at 0x%p (irq %d)\n",
+			ssc->regs, ssc->irq);
+
+	goto out;
+
+out_unmap:
+	iounmap(ssc->regs);
+out_clk:
+	clk_put(ssc->clk);
+out_free:
+	kfree(ssc);
+out:
+	return retval;
+}
+
+static int __devexit ssc_remove(struct platform_device *pdev)
+{
+	struct ssc_device *ssc = platform_get_drvdata(pdev);
+
+	spin_lock(&user_lock);
+	iounmap(ssc->regs);
+	clk_put(ssc->clk);
+	list_del(&ssc->list);
+	kfree(ssc);
+	spin_unlock(&user_lock);
+
+	return 0;
+}
+
+static struct platform_driver ssc_driver = {
+	.remove		= __devexit_p(ssc_remove),
+	.driver		= {
+		.name		= "ssc",
+	},
+};
+
+static int __init ssc_init(void)
+{
+	return platform_driver_probe(&ssc_driver, ssc_probe);
+}
+module_init(ssc_init);
+
+static void __exit ssc_exit(void)
+{
+	platform_driver_unregister(&ssc_driver);
+}
+module_exit(ssc_exit);
+
+MODULE_AUTHOR("Hans-Christian Egtvedt <hcegtvedt@atmel.com>");
+MODULE_DESCRIPTION("SSC driver for Atmel AVR32 and AT91");
+MODULE_LICENSE("GPL");