2 * Copyright (c) 2014, The Linux foundation. All rights reserved.
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License rev 2 and
6 * only rev 2 as published by the free Software foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or fITNESS fOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
14 #include <linux/clk.h>
15 #include <linux/err.h>
17 #include <linux/module.h>
19 #include <linux/of_platform.h>
20 #include <linux/platform_device.h>
22 #define GSBI_CTRL_REG 0x0000
23 #define GSBI_PROTOCOL_SHIFT 4
25 static int gsbi_probe(struct platform_device *pdev)
27 struct device_node *node = pdev->dev.of_node;
33 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
34 base = devm_ioremap_resource(&pdev->dev, res);
38 if (of_property_read_u32(node, "qcom,mode", &mode)) {
39 dev_err(&pdev->dev, "missing mode configuration\n");
43 /* not required, so default to 0 if not present */
44 of_property_read_u32(node, "qcom,crci", &crci);
46 dev_info(&pdev->dev, "GSBI port protocol: %d crci: %d\n", mode, crci);
48 hclk = devm_clk_get(&pdev->dev, "iface");
52 clk_prepare_enable(hclk);
54 writel_relaxed((mode << GSBI_PROTOCOL_SHIFT) | crci,
55 base + GSBI_CTRL_REG);
57 /* make sure the gsbi control write is not reordered */
60 clk_disable_unprepare(hclk);
62 return of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev);
65 static const struct of_device_id gsbi_dt_match[] = {
66 { .compatible = "qcom,gsbi-v1.0.0", },
70 MODULE_DEVICE_TABLE(of, gsbi_dt_match);
72 static struct platform_driver gsbi_driver = {
76 .of_match_table = gsbi_dt_match,
81 module_platform_driver(gsbi_driver);
83 MODULE_AUTHOR("Andy Gross <agross@codeaurora.org>");
84 MODULE_DESCRIPTION("QCOM GSBI driver");
85 MODULE_LICENSE("GPL v2");