drivers/memory/atmel-sdramc.c

   1 /*
   2  * Atmel (Multi-port DDR-)SDRAM Controller driver
   3  *
   4  * Copyright (C) 2014 Atmel
   5  *
   6  * This program is free software: you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation version 2 of the License.
   9  *
  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, see <http://www.gnu.org/licenses/>.
  17  *
  18  */
  19
  20 #include <linux/clk.h>
  21 #include <linux/err.h>
  22 #include <linux/kernel.h>
  23 #include <linux/module.h>
  24 #include <linux/of_platform.h>
  25 #include <linux/platform_device.h>
  26
  27 struct at91_ramc_caps {
  28         bool has_ddrck;
  29         bool has_mpddr_clk;
  30 };
  31
  32 static const struct at91_ramc_caps at91rm9200_caps = { };
  33
  34 static const struct at91_ramc_caps at91sam9g45_caps = {
  35         .has_ddrck = 1,
  36         .has_mpddr_clk = 0,
  37 };
  38
  39 static const struct at91_ramc_caps sama5d3_caps = {
  40         .has_ddrck = 1,
  41         .has_mpddr_clk = 1,
  42 };
  43
  44 static const struct of_device_id atmel_ramc_of_match[] = {
  45         { .compatible = "atmel,at91rm9200-sdramc", .data = &at91rm9200_caps, },
  46         { .compatible = "atmel,at91sam9260-sdramc", .data = &at91rm9200_caps, },
  47         { .compatible = "atmel,at91sam9g45-ddramc", .data = &at91sam9g45_caps, },
  48         { .compatible = "atmel,sama5d3-ddramc", .data = &sama5d3_caps, },
  49         {},
  50 };
  51 MODULE_DEVICE_TABLE(of, atmel_ramc_of_match);
  52
  53 static int atmel_ramc_probe(struct platform_device *pdev)
  54 {
  55         const struct of_device_id *match;
  56         const struct at91_ramc_caps *caps;
  57         struct clk *clk;
  58
  59         match = of_match_device(atmel_ramc_of_match, &pdev->dev);
  60         caps = match->data;
  61
  62         if (caps->has_ddrck) {
  63                 clk = devm_clk_get(&pdev->dev, "ddrck");
  64                 if (IS_ERR(clk))
  65                         return PTR_ERR(clk);
  66                 clk_prepare_enable(clk);
  67         }
  68
  69         if (caps->has_mpddr_clk) {
  70                 clk = devm_clk_get(&pdev->dev, "mpddr");
  71                 if (IS_ERR(clk)) {
  72                         pr_err("AT91 RAMC: couldn't get mpddr clock\n");
  73                         return PTR_ERR(clk);
  74                 }
  75                 clk_prepare_enable(clk);
  76         }
  77
  78         return 0;
  79 }
  80
  81 static struct platform_driver atmel_ramc_driver = {
  82         .probe          = atmel_ramc_probe,
  83         .driver         = {
  84                 .name   = "atmel-ramc",
  85                 .of_match_table = atmel_ramc_of_match,
  86         },
  87 };
  88
  89 static int __init atmel_ramc_init(void)
  90 {
  91         return platform_driver_register(&atmel_ramc_driver);
  92 }
  93 module_init(atmel_ramc_init);
  94
  95 MODULE_LICENSE("GPL v2");
  96 MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@free-electrons.com>");
  97 MODULE_DESCRIPTION("Atmel (Multi-port DDR-)SDRAM Controller");