diff options
Diffstat (limited to 'drivers/soc/qcom/qcom_gsbi.c')
-rw-r--r-- | drivers/soc/qcom/qcom_gsbi.c | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/drivers/soc/qcom/qcom_gsbi.c b/drivers/soc/qcom/qcom_gsbi.c new file mode 100644 index 000000000000..447458e696a9 --- /dev/null +++ b/drivers/soc/qcom/qcom_gsbi.c @@ -0,0 +1,85 @@ +/* + * 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"); |