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/*
* Copyright (C) 2014 Chen-Yu Tsai
* Author: Chen-Yu Tsai <wens@csie.org>
*
* Allwinner A23 APB0 clock driver
*
* License Terms: GNU General Public License v2
*
* 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/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;
struct resource *r;
void __iomem *reg;
struct clk *clk;
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
reg = devm_ioremap_resource(&pdev->dev, r);
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);
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