linux/drivers/memory/atmel-sdramc.c
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   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
  17struct at91_ramc_caps {
  18        bool has_ddrck;
  19        bool has_mpddr_clk;
  20};
  21
  22static const struct at91_ramc_caps at91rm9200_caps = { };
  23
  24static const struct at91_ramc_caps at91sam9g45_caps = {
  25        .has_ddrck = 1,
  26        .has_mpddr_clk = 0,
  27};
  28
  29static const struct at91_ramc_caps sama5d3_caps = {
  30        .has_ddrck = 1,
  31        .has_mpddr_clk = 1,
  32};
  33
  34static 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
  42static 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
  68static 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
  76builtin_platform_driver(atmel_ramc_driver);
  77