blob: afe66571ce0b7bfde98f05a1a75175f250482fa5 [file] [log] [blame]
Philipp Zabel4984c6f2013-04-29 16:17:12 -07001/*
2 * Generic on-chip SRAM allocation driver
3 *
4 * Copyright (C) 2012 Philipp Zabel, Pengutronix
5 *
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.
14 *
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,
18 * MA 02110-1301, USA.
19 */
20
21#include <linux/kernel.h>
22#include <linux/init.h>
23#include <linux/clk.h>
24#include <linux/err.h>
25#include <linux/io.h>
26#include <linux/of.h>
27#include <linux/platform_device.h>
28#include <linux/slab.h>
29#include <linux/spinlock.h>
30#include <linux/genalloc.h>
31
32#define SRAM_GRANULARITY 32
33
34struct sram_dev {
35 struct gen_pool *pool;
36 struct clk *clk;
37};
38
39static int sram_probe(struct platform_device *pdev)
40{
41 void __iomem *virt_base;
42 struct sram_dev *sram;
43 struct resource *res;
44 unsigned long size;
45 int ret;
46
47 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
Laurent Navet21b066f2013-05-02 14:39:34 +020048 virt_base = devm_ioremap_resource(&pdev->dev, res);
49 if (IS_ERR(virt_base))
50 return PTR_ERR(virt_base);
51
Alexander Shiyanf3cbfa52013-06-10 18:43:53 +040052 size = resource_size(res);
Philipp Zabel4984c6f2013-04-29 16:17:12 -070053
54 sram = devm_kzalloc(&pdev->dev, sizeof(*sram), GFP_KERNEL);
55 if (!sram)
56 return -ENOMEM;
57
58 sram->clk = devm_clk_get(&pdev->dev, NULL);
59 if (IS_ERR(sram->clk))
60 sram->clk = NULL;
61 else
62 clk_prepare_enable(sram->clk);
63
64 sram->pool = devm_gen_pool_create(&pdev->dev, ilog2(SRAM_GRANULARITY), -1);
65 if (!sram->pool)
66 return -ENOMEM;
67
68 ret = gen_pool_add_virt(sram->pool, (unsigned long)virt_base,
69 res->start, size, -1);
70 if (ret < 0) {
Heiko Stübner5f90b9b2013-07-05 14:40:53 +020071 if (sram->clk)
72 clk_disable_unprepare(sram->clk);
Philipp Zabel4984c6f2013-04-29 16:17:12 -070073 return ret;
74 }
75
76 platform_set_drvdata(pdev, sram);
77
78 dev_dbg(&pdev->dev, "SRAM pool: %ld KiB @ 0x%p\n", size / 1024, virt_base);
79
80 return 0;
81}
82
83static int sram_remove(struct platform_device *pdev)
84{
85 struct sram_dev *sram = platform_get_drvdata(pdev);
86
87 if (gen_pool_avail(sram->pool) < gen_pool_size(sram->pool))
88 dev_dbg(&pdev->dev, "removed while SRAM allocated\n");
89
90 gen_pool_destroy(sram->pool);
91
92 if (sram->clk)
93 clk_disable_unprepare(sram->clk);
94
95 return 0;
96}
97
98#ifdef CONFIG_OF
99static struct of_device_id sram_dt_ids[] = {
100 { .compatible = "mmio-sram" },
101 {}
102};
103#endif
104
105static struct platform_driver sram_driver = {
106 .driver = {
107 .name = "sram",
108 .of_match_table = of_match_ptr(sram_dt_ids),
109 },
110 .probe = sram_probe,
111 .remove = sram_remove,
112};
113
114static int __init sram_init(void)
115{
116 return platform_driver_register(&sram_driver);
117}
118
119postcore_initcall(sram_init);