2 * Generic on-chip SRAM allocation driver
4 * Copyright (C) 2012 Philipp Zabel, Pengutronix
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version 2
9 * of the License, or (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
21 #include <linux/kernel.h>
22 #include <linux/init.h>
23 #include <linux/clk.h>
24 #include <linux/err.h>
27 #include <linux/platform_device.h>
28 #include <linux/slab.h>
29 #include <linux/spinlock.h>
30 #include <linux/genalloc.h>
31 #include <linux/platform_data/sram.h>
33 #define SRAM_GRANULARITY 32
36 struct gen_pool *pool;
40 static int sram_probe(struct platform_device *pdev)
42 struct sram_platform_data *pdata = pdev->dev.platform_data;
43 void __iomem *virt_base;
44 struct sram_dev *sram;
47 bool map_exec = false;
50 if (of_get_property(pdev->dev.of_node, "map-exec", NULL))
52 if (pdata && pdata->map_exec)
55 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
56 if (res && of_get_property(pdev->dev.of_node, "map-cacheable", NULL))
57 res->flags |= IORESOURCE_CACHEABLE;
59 virt_base = devm_ioremap_exec_resource(&pdev->dev, res);
61 virt_base = devm_ioremap_resource(&pdev->dev, res);
62 if (IS_ERR(virt_base))
63 return PTR_ERR(virt_base);
65 size = resource_size(res);
67 sram = devm_kzalloc(&pdev->dev, sizeof(*sram), GFP_KERNEL);
71 sram->clk = devm_clk_get(&pdev->dev, NULL);
72 if (IS_ERR(sram->clk))
75 clk_prepare_enable(sram->clk);
77 sram->pool = devm_gen_pool_create(&pdev->dev, ilog2(SRAM_GRANULARITY), -1);
81 ret = gen_pool_add_virt(sram->pool, (unsigned long)virt_base,
82 res->start, size, -1);
84 gen_pool_destroy(sram->pool);
88 platform_set_drvdata(pdev, sram);
90 dev_dbg(&pdev->dev, "SRAM pool: %ld KiB @ 0x%p\n", size / 1024, virt_base);
95 static int sram_remove(struct platform_device *pdev)
97 struct sram_dev *sram = platform_get_drvdata(pdev);
99 if (gen_pool_avail(sram->pool) < gen_pool_size(sram->pool))
100 dev_dbg(&pdev->dev, "removed while SRAM allocated\n");
102 gen_pool_destroy(sram->pool);
105 clk_disable_unprepare(sram->clk);
111 static struct of_device_id sram_dt_ids[] = {
112 { .compatible = "mmio-sram" },
117 static struct platform_driver sram_driver = {
120 .of_match_table = of_match_ptr(sram_dt_ids),
123 .remove = sram_remove,
126 static int __init sram_init(void)
128 return platform_driver_register(&sram_driver);
131 postcore_initcall(sram_init);