/* * 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);	virt_base = devm_ioremap_resource(&pdev->dev, res);	if (IS_ERR(virt_base))		return PTR_ERR(virt_base); 	size = resource_size(res); 	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) {		if (sram->clk)			clk_disable_unprepare(sram->clk);		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_OFstatic 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);