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linux-next/drivers/memory/atmel-sdramc.c
LABBE Corentin 7922118f8f memory: atmel-sdramc: fix a possible NULL dereference
of_match_device could return NULL, and so cause a NULL pointer
dereference later.

For fixing this problem, we use of_device_get_match_data(), this will
simplify the code a little by using a standard function for
getting the match data.

Signed-off-by: LABBE Corentin <clabbe.montjoie@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2016-08-31 19:19:16 +02:00

93 lines
2.4 KiB
C

/*
* Atmel (Multi-port DDR-)SDRAM Controller driver
*
* Author: Alexandre Belloni <alexandre.belloni@free-electrons.com>
*
* Copyright (C) 2014 Atmel
*
* 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 version 2 of the License.
*
* 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, see <http://www.gnu.org/licenses/>.
*
*/
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
struct at91_ramc_caps {
bool has_ddrck;
bool has_mpddr_clk;
};
static const struct at91_ramc_caps at91rm9200_caps = { };
static const struct at91_ramc_caps at91sam9g45_caps = {
.has_ddrck = 1,
.has_mpddr_clk = 0,
};
static const struct at91_ramc_caps sama5d3_caps = {
.has_ddrck = 1,
.has_mpddr_clk = 1,
};
static const struct of_device_id atmel_ramc_of_match[] = {
{ .compatible = "atmel,at91rm9200-sdramc", .data = &at91rm9200_caps, },
{ .compatible = "atmel,at91sam9260-sdramc", .data = &at91rm9200_caps, },
{ .compatible = "atmel,at91sam9g45-ddramc", .data = &at91sam9g45_caps, },
{ .compatible = "atmel,sama5d3-ddramc", .data = &sama5d3_caps, },
{},
};
static int atmel_ramc_probe(struct platform_device *pdev)
{
const struct at91_ramc_caps *caps;
struct clk *clk;
caps = of_device_get_match_data(&pdev->dev);
if (caps->has_ddrck) {
clk = devm_clk_get(&pdev->dev, "ddrck");
if (IS_ERR(clk))
return PTR_ERR(clk);
clk_prepare_enable(clk);
}
if (caps->has_mpddr_clk) {
clk = devm_clk_get(&pdev->dev, "mpddr");
if (IS_ERR(clk)) {
pr_err("AT91 RAMC: couldn't get mpddr clock\n");
return PTR_ERR(clk);
}
clk_prepare_enable(clk);
}
return 0;
}
static struct platform_driver atmel_ramc_driver = {
.probe = atmel_ramc_probe,
.driver = {
.name = "atmel-ramc",
.of_match_table = atmel_ramc_of_match,
},
};
static int __init atmel_ramc_init(void)
{
return platform_driver_register(&atmel_ramc_driver);
}
device_initcall(atmel_ramc_init);