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
atmel_ramc_probe(struct platform_device * pdev)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 .owner = THIS_MODULE,
86 .of_match_table = atmel_ramc_of_match,
87 },
88 };
89
atmel_ramc_init(void)90 static int __init atmel_ramc_init(void)
91 {
92 return platform_driver_register(&atmel_ramc_driver);
93 }
94 module_init(atmel_ramc_init);
95
96 MODULE_LICENSE("GPL v2");
97 MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@free-electrons.com>");
98 MODULE_DESCRIPTION("Atmel (Multi-port DDR-)SDRAM Controller");
99