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| author | Frederic Weisbecker <fweisbec@gmail.com> | 2013-05-02 17:37:49 +0200 | 
|---|---|---|
| committer | Frederic Weisbecker <fweisbec@gmail.com> | 2013-05-02 17:54:19 +0200 | 
| commit | c032862fba51a3ca504752d3a25186b324c5ce83 (patch) | |
| tree | 955dc2ba4ab3df76ecc2bb780ee84aca04967e8d /drivers/misc/sram.c | |
| parent | fda76e074c7737fc57855dd17c762e50ed526052 (diff) | |
| parent | 8700c95adb033843fc163d112b9d21d4fda78018 (diff) | |
| download | olio-linux-3.10-c032862fba51a3ca504752d3a25186b324c5ce83.tar.xz olio-linux-3.10-c032862fba51a3ca504752d3a25186b324c5ce83.zip  | |
Merge commit '8700c95adb03' into timers/nohz
The full dynticks tree needs the latest RCU and sched
upstream updates in order to fix some dependencies.
Merge a common upstream merge point that has these
updates.
Conflicts:
	include/linux/perf_event.h
	kernel/rcutree.h
	kernel/rcutree_plugin.h
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Diffstat (limited to 'drivers/misc/sram.c')
| -rw-r--r-- | drivers/misc/sram.c | 121 | 
1 files changed, 121 insertions, 0 deletions
diff --git a/drivers/misc/sram.c b/drivers/misc/sram.c new file mode 100644 index 00000000000..437192e4300 --- /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);  |