120 lines
2.7 KiB
C
120 lines
2.7 KiB
C
/*
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* Copyright (C) 2014 Chen-Yu Tsai
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* Author: Chen-Yu Tsai <wens@csie.org>
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*
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* Allwinner A23 APB0 clock driver
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*
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* License Terms: GNU General Public License v2
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*
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* Based on clk-sun6i-apb0.c
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* Allwinner A31 APB0 clock driver
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*
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* Copyright (C) 2014 Free Electrons
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* Author: Boris BREZILLON <boris.brezillon@free-electrons.com>
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*
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*/
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#include <linux/clk-provider.h>
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#include <linux/init.h>
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#include <linux/of.h>
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#include <linux/of_address.h>
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#include <linux/platform_device.h>
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static struct clk *sun8i_a23_apb0_register(struct device_node *node,
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void __iomem *reg)
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{
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const char *clk_name = node->name;
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const char *clk_parent;
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struct clk *clk;
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int ret;
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clk_parent = of_clk_get_parent_name(node, 0);
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if (!clk_parent)
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return ERR_PTR(-EINVAL);
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of_property_read_string(node, "clock-output-names", &clk_name);
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/* The A23 APB0 clock is a standard 2 bit wide divider clock */
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clk = clk_register_divider(NULL, clk_name, clk_parent, 0, reg,
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0, 2, 0, NULL);
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if (IS_ERR(clk))
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return clk;
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ret = of_clk_add_provider(node, of_clk_src_simple_get, clk);
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if (ret)
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goto err_unregister;
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return clk;
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err_unregister:
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clk_unregister_divider(clk);
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return ERR_PTR(ret);
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}
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static void sun8i_a23_apb0_setup(struct device_node *node)
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{
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void __iomem *reg;
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struct resource res;
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struct clk *clk;
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reg = of_io_request_and_map(node, 0, of_node_full_name(node));
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if (IS_ERR(reg)) {
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/*
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* This happens with clk nodes instantiated through mfd,
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* as those do not have their resources assigned in the
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* device tree. Do not print an error in this case.
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*/
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if (PTR_ERR(reg) != -EINVAL)
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pr_err("Could not get registers for a23-apb0-clk\n");
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return;
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}
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clk = sun8i_a23_apb0_register(node, reg);
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if (IS_ERR(clk))
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goto err_unmap;
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return;
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err_unmap:
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iounmap(reg);
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of_address_to_resource(node, 0, &res);
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release_mem_region(res.start, resource_size(&res));
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}
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CLK_OF_DECLARE_DRIVER(sun8i_a23_apb0, "allwinner,sun8i-a23-apb0-clk",
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sun8i_a23_apb0_setup);
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static int sun8i_a23_apb0_clk_probe(struct platform_device *pdev)
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{
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struct device_node *np = pdev->dev.of_node;
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struct resource *r;
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void __iomem *reg;
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struct clk *clk;
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r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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reg = devm_ioremap_resource(&pdev->dev, r);
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if (IS_ERR(reg))
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return PTR_ERR(reg);
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clk = sun8i_a23_apb0_register(np, reg);
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if (IS_ERR(clk))
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return PTR_ERR(clk);
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return 0;
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}
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static const struct of_device_id sun8i_a23_apb0_clk_dt_ids[] = {
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{ .compatible = "allwinner,sun8i-a23-apb0-clk" },
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{ /* sentinel */ }
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};
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static struct platform_driver sun8i_a23_apb0_clk_driver = {
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.driver = {
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.name = "sun8i-a23-apb0-clk",
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.of_match_table = sun8i_a23_apb0_clk_dt_ids,
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},
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.probe = sun8i_a23_apb0_clk_probe,
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};
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builtin_platform_driver(sun8i_a23_apb0_clk_driver);
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