linux/drivers/memory/atmel-sdramc.c
Alexandre Belloni e81b6abebc memory: add a driver for atmel ram controllers
Atmel SoCs have one or multiple RAM controllers that need one or multiple clocks
to run.
This driver handle those clocks.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
2014-07-15 11:43:42 +02:00

99 lines
2.6 KiB
C

/*
* Atmel (Multi-port DDR-)SDRAM Controller driver
*
* 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/module.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, },
{},
};
MODULE_DEVICE_TABLE(of, atmel_ramc_of_match);
static int atmel_ramc_probe(struct platform_device *pdev)
{
const struct of_device_id *match;
const struct at91_ramc_caps *caps;
struct clk *clk;
match = of_match_device(atmel_ramc_of_match, &pdev->dev);
caps = match->data;
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",
.owner = THIS_MODULE,
.of_match_table = atmel_ramc_of_match,
},
};
static int __init atmel_ramc_init(void)
{
return platform_driver_register(&atmel_ramc_driver);
}
module_init(atmel_ramc_init);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@free-electrons.com>");
MODULE_DESCRIPTION("Atmel (Multi-port DDR-)SDRAM Controller");