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path: root/drivers/clk/sunxi/clk-sun8i-apb0.c
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Diffstat (limited to 'drivers/clk/sunxi/clk-sun8i-apb0.c')
-rw-r--r--drivers/clk/sunxi/clk-sun8i-apb0.c113
1 files changed, 113 insertions, 0 deletions
diff --git a/drivers/clk/sunxi/clk-sun8i-apb0.c b/drivers/clk/sunxi/clk-sun8i-apb0.c
new file mode 100644
index 000000000..f605ecca8
--- /dev/null
+++ b/drivers/clk/sunxi/clk-sun8i-apb0.c
@@ -0,0 +1,113 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2014 Chen-Yu Tsai
+ * Author: Chen-Yu Tsai <wens@csie.org>
+ *
+ * Allwinner A23 APB0 clock driver
+ *
+ * Based on clk-sun6i-apb0.c
+ * Allwinner A31 APB0 clock driver
+ *
+ * Copyright (C) 2014 Free Electrons
+ * Author: Boris BREZILLON <boris.brezillon@free-electrons.com>
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+
+static struct clk *sun8i_a23_apb0_register(struct device_node *node,
+ void __iomem *reg)
+{
+ const char *clk_name = node->name;
+ const char *clk_parent;
+ struct clk *clk;
+ int ret;
+
+ clk_parent = of_clk_get_parent_name(node, 0);
+ if (!clk_parent)
+ return ERR_PTR(-EINVAL);
+
+ of_property_read_string(node, "clock-output-names", &clk_name);
+
+ /* The A23 APB0 clock is a standard 2 bit wide divider clock */
+ clk = clk_register_divider(NULL, clk_name, clk_parent, 0, reg,
+ 0, 2, 0, NULL);
+ if (IS_ERR(clk))
+ return clk;
+
+ ret = of_clk_add_provider(node, of_clk_src_simple_get, clk);
+ if (ret)
+ goto err_unregister;
+
+ return clk;
+
+err_unregister:
+ clk_unregister_divider(clk);
+
+ return ERR_PTR(ret);
+}
+
+static void sun8i_a23_apb0_setup(struct device_node *node)
+{
+ void __iomem *reg;
+ struct resource res;
+ struct clk *clk;
+
+ reg = of_io_request_and_map(node, 0, of_node_full_name(node));
+ if (IS_ERR(reg)) {
+ /*
+ * This happens with clk nodes instantiated through mfd,
+ * as those do not have their resources assigned in the
+ * device tree. Do not print an error in this case.
+ */
+ if (PTR_ERR(reg) != -EINVAL)
+ pr_err("Could not get registers for a23-apb0-clk\n");
+
+ return;
+ }
+
+ clk = sun8i_a23_apb0_register(node, reg);
+ if (IS_ERR(clk))
+ goto err_unmap;
+
+ return;
+
+err_unmap:
+ iounmap(reg);
+ of_address_to_resource(node, 0, &res);
+ release_mem_region(res.start, resource_size(&res));
+}
+CLK_OF_DECLARE_DRIVER(sun8i_a23_apb0, "allwinner,sun8i-a23-apb0-clk",
+ sun8i_a23_apb0_setup);
+
+static int sun8i_a23_apb0_clk_probe(struct platform_device *pdev)
+{
+ struct device_node *np = pdev->dev.of_node;
+ void __iomem *reg;
+ struct clk *clk;
+
+ reg = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(reg))
+ return PTR_ERR(reg);
+
+ clk = sun8i_a23_apb0_register(np, reg);
+ return PTR_ERR_OR_ZERO(clk);
+}
+
+static const struct of_device_id sun8i_a23_apb0_clk_dt_ids[] = {
+ { .compatible = "allwinner,sun8i-a23-apb0-clk" },
+ { /* sentinel */ }
+};
+
+static struct platform_driver sun8i_a23_apb0_clk_driver = {
+ .driver = {
+ .name = "sun8i-a23-apb0-clk",
+ .of_match_table = sun8i_a23_apb0_clk_dt_ids,
+ },
+ .probe = sun8i_a23_apb0_clk_probe,
+};
+builtin_platform_driver(sun8i_a23_apb0_clk_driver);