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authorAndy Gross <agross@codeaurora.org>2014-04-24 20:31:21 +0400
committerKumar Gala <galak@codeaurora.org>2014-05-23 20:38:04 +0400
commit5d144e36b7c51612922fa05d37ff3a869261cc82 (patch)
treea2e4dd5f202555ae8bf7be7a0b63b44b14324152 /drivers/soc/qcom/qcom_gsbi.c
parent3a6e08218f36baa9c49282ad2fe0dfbf001d8f23 (diff)
downloadlinux-5d144e36b7c51612922fa05d37ff3a869261cc82.tar.xz
soc: qcom: Add GSBI driver
The GSBI (General Serial Bus Interface) driver controls the overarching configuration of the shared serial bus infrastructure on APQ8064, IPQ8064, and earlier QCOM processors. The GSBI supports UART, I2C, SPI, and UIM functionality in various combinations. Signed-off-by: Andy Gross <agross@codeaurora.org> Signed-off-by: Kumar Gala <galak@codeaurora.org>
Diffstat (limited to 'drivers/soc/qcom/qcom_gsbi.c')
-rw-r--r--drivers/soc/qcom/qcom_gsbi.c84
1 files changed, 84 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..061dd0632dbd
--- /dev/null
+++ b/drivers/soc/qcom/qcom_gsbi.c
@@ -0,0 +1,84 @@
+/*
+ * 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");