drivers/memory/atmel-sdramc.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Atmel (Multi-port DDR-)SDRAM Controller driver
   4  *
   5  * Author: Alexandre Belloni <alexandre.belloni@free-electrons.com>
   6  *
   7  * Copyright (C) 2014 Atmel
   8  */
   9
  10 #include <linux/clk.h>
  11 #include <linux/err.h>
  12 #include <linux/kernel.h>
  13 #include <linux/init.h>
  14 #include <linux/of_platform.h>
  15 #include <linux/platform_device.h>
  16
  17 struct at91_ramc_caps {
  18         bool has_ddrck;
  19         bool has_mpddr_clk;
  20 };
  21
  22 static const struct at91_ramc_caps at91rm9200_caps = { };
  23
  24 static const struct at91_ramc_caps at91sam9g45_caps = {
  25         .has_ddrck = 1,
  26         .has_mpddr_clk = 0,
  27 };
  28
  29 static const struct at91_ramc_caps sama5d3_caps = {
  30         .has_ddrck = 1,
  31         .has_mpddr_clk = 1,
  32 };
  33
  34 static const struct of_device_id atmel_ramc_of_match[] = {
  35         { .compatible = "atmel,at91rm9200-sdramc", .data = &at91rm9200_caps, },
  36         { .compatible = "atmel,at91sam9260-sdramc", .data = &at91rm9200_caps, },
  37         { .compatible = "atmel,at91sam9g45-ddramc", .data = &at91sam9g45_caps, },
  38         { .compatible = "atmel,sama5d3-ddramc", .data = &sama5d3_caps, },
  39         {},
  40 };
  41
  42 static int atmel_ramc_probe(struct platform_device *pdev)
  43 {
  44         const struct at91_ramc_caps *caps;
  45         struct clk *clk;
  46
  47         caps = of_device_get_match_data(&pdev->dev);
  48
  49         if (caps->has_ddrck) {
  50                 clk = devm_clk_get(&pdev->dev, "ddrck");
  51                 if (IS_ERR(clk))
  52                         return PTR_ERR(clk);
  53                 clk_prepare_enable(clk);
  54         }
  55
  56         if (caps->has_mpddr_clk) {
  57                 clk = devm_clk_get(&pdev->dev, "mpddr");
  58                 if (IS_ERR(clk)) {
  59                         pr_err("AT91 RAMC: couldn't get mpddr clock\n");
  60                         return PTR_ERR(clk);
  61                 }
  62                 clk_prepare_enable(clk);
  63         }
  64
  65         return 0;
  66 }
  67
  68 static struct platform_driver atmel_ramc_driver = {
  69         .probe          = atmel_ramc_probe,
  70         .driver         = {
  71                 .name   = "atmel-ramc",
  72                 .of_match_table = atmel_ramc_of_match,
  73         },
  74 };
  75
  76 builtin_platform_driver(atmel_ramc_driver);