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/*
* Copyright (c) 2014, The Linux foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License rev 2 and
* only rev 2 as published by the free Software foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or fITNESS fOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#define GSBI_CTRL_REG 0x0000
#define GSBI_PROTOCOL_SHIFT 4
static int gsbi_probe(struct platform_device *pdev)
{
struct device_node *node = pdev->dev.of_node;
struct resource *res;
void __iomem *base;
struct clk *hclk;
u32 mode, crci = 0;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(base))
return PTR_ERR(base);
if (of_property_read_u32(node, "qcom,mode", &mode)) {
dev_err(&pdev->dev, "missing mode configuration\n");
return -EINVAL;
}
/* not required, so default to 0 if not present */
of_property_read_u32(node, "qcom,crci", &crci);
dev_info(&pdev->dev, "GSBI port protocol: %d crci: %d\n", mode, crci);
hclk = devm_clk_get(&pdev->dev, "iface");
if (IS_ERR(hclk))
return PTR_ERR(hclk);
clk_prepare_enable(hclk);
writel_relaxed((mode << GSBI_PROTOCOL_SHIFT) | crci,
base + GSBI_CTRL_REG);
/* make sure the gsbi control write is not reordered */
wmb();
clk_disable_unprepare(hclk);
return of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev);
}
static const struct of_device_id gsbi_dt_match[] = {
{ .compatible = "qcom,gsbi-v1.0.0", },
{ },
};
MODULE_DEVICE_TABLE(of, gsbi_dt_match);
static struct platform_driver gsbi_driver = {
.driver = {
.name = "gsbi",
.owner = THIS_MODULE,
.of_match_table = gsbi_dt_match,
},
.probe = gsbi_probe,
};
module_platform_driver(gsbi_driver);
MODULE_AUTHOR("Andy Gross <agross@codeaurora.org>");
MODULE_DESCRIPTION("QCOM GSBI driver");
MODULE_LICENSE("GPL v2");
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