1 files changed, 121 insertions, 0 deletions
diff --git a/drivers/misc/sram.c b/drivers/misc/sram.c
new file mode 100644
index 000000000000..437192e43006
--- /dev/null
+++ b/drivers/misc/sram.c
@@ -0,0 +1,121 @@
+/*
+ * Generic on-chip SRAM allocation driver
+ *
+ * Copyright (C) 2012 Philipp Zabel, Pengutronix
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/genalloc.h>
+
+#define SRAM_GRANULARITY	32
+
+struct sram_dev {
+	struct gen_pool *pool;
+	struct clk *clk;
+};
+
+static int sram_probe(struct platform_device *pdev)
+{
+	void __iomem *virt_base;
+	struct sram_dev *sram;
+	struct resource *res;
+	unsigned long size;
+	int ret;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -EINVAL;
+
+	size = resource_size(res);
+
+	virt_base = devm_request_and_ioremap(&pdev->dev, res);
+	if (!virt_base)
+		return -EADDRNOTAVAIL;
+
+	sram = devm_kzalloc(&pdev->dev, sizeof(*sram), GFP_KERNEL);
+	if (!sram)
+		return -ENOMEM;
+
+	sram->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(sram->clk))
+		sram->clk = NULL;
+	else
+		clk_prepare_enable(sram->clk);
+
+	sram->pool = devm_gen_pool_create(&pdev->dev, ilog2(SRAM_GRANULARITY), -1);
+	if (!sram->pool)
+		return -ENOMEM;
+
+	ret = gen_pool_add_virt(sram->pool, (unsigned long)virt_base,
+				res->start, size, -1);
+	if (ret < 0) {
+		gen_pool_destroy(sram->pool);
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, sram);
+
+	dev_dbg(&pdev->dev, "SRAM pool: %ld KiB @ 0x%p\n", size / 1024, virt_base);
+
+	return 0;
+}
+
+static int sram_remove(struct platform_device *pdev)
+{
+	struct sram_dev *sram = platform_get_drvdata(pdev);
+
+	if (gen_pool_avail(sram->pool) < gen_pool_size(sram->pool))
+		dev_dbg(&pdev->dev, "removed while SRAM allocated\n");
+
+	gen_pool_destroy(sram->pool);
+
+	if (sram->clk)
+		clk_disable_unprepare(sram->clk);
+
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static struct of_device_id sram_dt_ids[] = {
+	{ .compatible = "mmio-sram" },
+	{}
+};
+#endif
+
+static struct platform_driver sram_driver = {
+	.driver = {
+		.name = "sram",
+		.of_match_table = of_match_ptr(sram_dt_ids),
+	},
+	.probe = sram_probe,
+	.remove = sram_remove,
+};
+
+static int __init sram_init(void)
+{
+	return platform_driver_register(&sram_driver);
+}
+
+postcore_initcall(sram_init);