| /* |
| * 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 4096 |
| |
| 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); |