1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-only
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Copyright (C) 2014 Chen-Yu Tsai
4*4882a593Smuzhiyun * Author: Chen-Yu Tsai <wens@csie.org>
5*4882a593Smuzhiyun *
6*4882a593Smuzhiyun * Allwinner A23 APB0 clock driver
7*4882a593Smuzhiyun *
8*4882a593Smuzhiyun * Based on clk-sun6i-apb0.c
9*4882a593Smuzhiyun * Allwinner A31 APB0 clock driver
10*4882a593Smuzhiyun *
11*4882a593Smuzhiyun * Copyright (C) 2014 Free Electrons
12*4882a593Smuzhiyun * Author: Boris BREZILLON <boris.brezillon@free-electrons.com>
13*4882a593Smuzhiyun */
14*4882a593Smuzhiyun
15*4882a593Smuzhiyun #include <linux/clk-provider.h>
16*4882a593Smuzhiyun #include <linux/init.h>
17*4882a593Smuzhiyun #include <linux/io.h>
18*4882a593Smuzhiyun #include <linux/of.h>
19*4882a593Smuzhiyun #include <linux/of_address.h>
20*4882a593Smuzhiyun #include <linux/platform_device.h>
21*4882a593Smuzhiyun
sun8i_a23_apb0_register(struct device_node * node,void __iomem * reg)22*4882a593Smuzhiyun static struct clk *sun8i_a23_apb0_register(struct device_node *node,
23*4882a593Smuzhiyun void __iomem *reg)
24*4882a593Smuzhiyun {
25*4882a593Smuzhiyun const char *clk_name = node->name;
26*4882a593Smuzhiyun const char *clk_parent;
27*4882a593Smuzhiyun struct clk *clk;
28*4882a593Smuzhiyun int ret;
29*4882a593Smuzhiyun
30*4882a593Smuzhiyun clk_parent = of_clk_get_parent_name(node, 0);
31*4882a593Smuzhiyun if (!clk_parent)
32*4882a593Smuzhiyun return ERR_PTR(-EINVAL);
33*4882a593Smuzhiyun
34*4882a593Smuzhiyun of_property_read_string(node, "clock-output-names", &clk_name);
35*4882a593Smuzhiyun
36*4882a593Smuzhiyun /* The A23 APB0 clock is a standard 2 bit wide divider clock */
37*4882a593Smuzhiyun clk = clk_register_divider(NULL, clk_name, clk_parent, 0, reg,
38*4882a593Smuzhiyun 0, 2, 0, NULL);
39*4882a593Smuzhiyun if (IS_ERR(clk))
40*4882a593Smuzhiyun return clk;
41*4882a593Smuzhiyun
42*4882a593Smuzhiyun ret = of_clk_add_provider(node, of_clk_src_simple_get, clk);
43*4882a593Smuzhiyun if (ret)
44*4882a593Smuzhiyun goto err_unregister;
45*4882a593Smuzhiyun
46*4882a593Smuzhiyun return clk;
47*4882a593Smuzhiyun
48*4882a593Smuzhiyun err_unregister:
49*4882a593Smuzhiyun clk_unregister_divider(clk);
50*4882a593Smuzhiyun
51*4882a593Smuzhiyun return ERR_PTR(ret);
52*4882a593Smuzhiyun }
53*4882a593Smuzhiyun
sun8i_a23_apb0_setup(struct device_node * node)54*4882a593Smuzhiyun static void sun8i_a23_apb0_setup(struct device_node *node)
55*4882a593Smuzhiyun {
56*4882a593Smuzhiyun void __iomem *reg;
57*4882a593Smuzhiyun struct resource res;
58*4882a593Smuzhiyun struct clk *clk;
59*4882a593Smuzhiyun
60*4882a593Smuzhiyun reg = of_io_request_and_map(node, 0, of_node_full_name(node));
61*4882a593Smuzhiyun if (IS_ERR(reg)) {
62*4882a593Smuzhiyun /*
63*4882a593Smuzhiyun * This happens with clk nodes instantiated through mfd,
64*4882a593Smuzhiyun * as those do not have their resources assigned in the
65*4882a593Smuzhiyun * device tree. Do not print an error in this case.
66*4882a593Smuzhiyun */
67*4882a593Smuzhiyun if (PTR_ERR(reg) != -EINVAL)
68*4882a593Smuzhiyun pr_err("Could not get registers for a23-apb0-clk\n");
69*4882a593Smuzhiyun
70*4882a593Smuzhiyun return;
71*4882a593Smuzhiyun }
72*4882a593Smuzhiyun
73*4882a593Smuzhiyun clk = sun8i_a23_apb0_register(node, reg);
74*4882a593Smuzhiyun if (IS_ERR(clk))
75*4882a593Smuzhiyun goto err_unmap;
76*4882a593Smuzhiyun
77*4882a593Smuzhiyun return;
78*4882a593Smuzhiyun
79*4882a593Smuzhiyun err_unmap:
80*4882a593Smuzhiyun iounmap(reg);
81*4882a593Smuzhiyun of_address_to_resource(node, 0, &res);
82*4882a593Smuzhiyun release_mem_region(res.start, resource_size(&res));
83*4882a593Smuzhiyun }
84*4882a593Smuzhiyun CLK_OF_DECLARE_DRIVER(sun8i_a23_apb0, "allwinner,sun8i-a23-apb0-clk",
85*4882a593Smuzhiyun sun8i_a23_apb0_setup);
86*4882a593Smuzhiyun
sun8i_a23_apb0_clk_probe(struct platform_device * pdev)87*4882a593Smuzhiyun static int sun8i_a23_apb0_clk_probe(struct platform_device *pdev)
88*4882a593Smuzhiyun {
89*4882a593Smuzhiyun struct device_node *np = pdev->dev.of_node;
90*4882a593Smuzhiyun struct resource *r;
91*4882a593Smuzhiyun void __iomem *reg;
92*4882a593Smuzhiyun struct clk *clk;
93*4882a593Smuzhiyun
94*4882a593Smuzhiyun r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
95*4882a593Smuzhiyun reg = devm_ioremap_resource(&pdev->dev, r);
96*4882a593Smuzhiyun if (IS_ERR(reg))
97*4882a593Smuzhiyun return PTR_ERR(reg);
98*4882a593Smuzhiyun
99*4882a593Smuzhiyun clk = sun8i_a23_apb0_register(np, reg);
100*4882a593Smuzhiyun return PTR_ERR_OR_ZERO(clk);
101*4882a593Smuzhiyun }
102*4882a593Smuzhiyun
103*4882a593Smuzhiyun static const struct of_device_id sun8i_a23_apb0_clk_dt_ids[] = {
104*4882a593Smuzhiyun { .compatible = "allwinner,sun8i-a23-apb0-clk" },
105*4882a593Smuzhiyun { /* sentinel */ }
106*4882a593Smuzhiyun };
107*4882a593Smuzhiyun
108*4882a593Smuzhiyun static struct platform_driver sun8i_a23_apb0_clk_driver = {
109*4882a593Smuzhiyun .driver = {
110*4882a593Smuzhiyun .name = "sun8i-a23-apb0-clk",
111*4882a593Smuzhiyun .of_match_table = sun8i_a23_apb0_clk_dt_ids,
112*4882a593Smuzhiyun },
113*4882a593Smuzhiyun .probe = sun8i_a23_apb0_clk_probe,
114*4882a593Smuzhiyun };
115*4882a593Smuzhiyun builtin_platform_driver(sun8i_a23_apb0_clk_driver);
116