1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-only
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Copyright (C) 2014 Free Electrons
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Author: Boris BREZILLON <boris.brezillon@free-electrons.com>
6*4882a593Smuzhiyun *
7*4882a593Smuzhiyun * Allwinner A31 AR100 clock driver
8*4882a593Smuzhiyun */
9*4882a593Smuzhiyun
10*4882a593Smuzhiyun #include <linux/bitops.h>
11*4882a593Smuzhiyun #include <linux/clk-provider.h>
12*4882a593Smuzhiyun #include <linux/init.h>
13*4882a593Smuzhiyun #include <linux/of.h>
14*4882a593Smuzhiyun #include <linux/platform_device.h>
15*4882a593Smuzhiyun #include <linux/spinlock.h>
16*4882a593Smuzhiyun
17*4882a593Smuzhiyun #include "clk-factors.h"
18*4882a593Smuzhiyun
19*4882a593Smuzhiyun /**
20*4882a593Smuzhiyun * sun6i_get_ar100_factors - Calculates factors p, m for AR100
21*4882a593Smuzhiyun *
22*4882a593Smuzhiyun * AR100 rate is calculated as follows
23*4882a593Smuzhiyun * rate = (parent_rate >> p) / (m + 1);
24*4882a593Smuzhiyun */
sun6i_get_ar100_factors(struct factors_request * req)25*4882a593Smuzhiyun static void sun6i_get_ar100_factors(struct factors_request *req)
26*4882a593Smuzhiyun {
27*4882a593Smuzhiyun unsigned long div;
28*4882a593Smuzhiyun int shift;
29*4882a593Smuzhiyun
30*4882a593Smuzhiyun /* clock only divides */
31*4882a593Smuzhiyun if (req->rate > req->parent_rate)
32*4882a593Smuzhiyun req->rate = req->parent_rate;
33*4882a593Smuzhiyun
34*4882a593Smuzhiyun div = DIV_ROUND_UP(req->parent_rate, req->rate);
35*4882a593Smuzhiyun
36*4882a593Smuzhiyun if (div < 32)
37*4882a593Smuzhiyun shift = 0;
38*4882a593Smuzhiyun else if (div >> 1 < 32)
39*4882a593Smuzhiyun shift = 1;
40*4882a593Smuzhiyun else if (div >> 2 < 32)
41*4882a593Smuzhiyun shift = 2;
42*4882a593Smuzhiyun else
43*4882a593Smuzhiyun shift = 3;
44*4882a593Smuzhiyun
45*4882a593Smuzhiyun div >>= shift;
46*4882a593Smuzhiyun
47*4882a593Smuzhiyun if (div > 32)
48*4882a593Smuzhiyun div = 32;
49*4882a593Smuzhiyun
50*4882a593Smuzhiyun req->rate = (req->parent_rate >> shift) / div;
51*4882a593Smuzhiyun req->m = div - 1;
52*4882a593Smuzhiyun req->p = shift;
53*4882a593Smuzhiyun }
54*4882a593Smuzhiyun
55*4882a593Smuzhiyun static const struct clk_factors_config sun6i_ar100_config = {
56*4882a593Smuzhiyun .mwidth = 5,
57*4882a593Smuzhiyun .mshift = 8,
58*4882a593Smuzhiyun .pwidth = 2,
59*4882a593Smuzhiyun .pshift = 4,
60*4882a593Smuzhiyun };
61*4882a593Smuzhiyun
62*4882a593Smuzhiyun static const struct factors_data sun6i_ar100_data = {
63*4882a593Smuzhiyun .mux = 16,
64*4882a593Smuzhiyun .muxmask = GENMASK(1, 0),
65*4882a593Smuzhiyun .table = &sun6i_ar100_config,
66*4882a593Smuzhiyun .getter = sun6i_get_ar100_factors,
67*4882a593Smuzhiyun };
68*4882a593Smuzhiyun
69*4882a593Smuzhiyun static DEFINE_SPINLOCK(sun6i_ar100_lock);
70*4882a593Smuzhiyun
sun6i_a31_ar100_clk_probe(struct platform_device * pdev)71*4882a593Smuzhiyun static int sun6i_a31_ar100_clk_probe(struct platform_device *pdev)
72*4882a593Smuzhiyun {
73*4882a593Smuzhiyun struct device_node *np = pdev->dev.of_node;
74*4882a593Smuzhiyun struct resource *r;
75*4882a593Smuzhiyun void __iomem *reg;
76*4882a593Smuzhiyun struct clk *clk;
77*4882a593Smuzhiyun
78*4882a593Smuzhiyun r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
79*4882a593Smuzhiyun reg = devm_ioremap_resource(&pdev->dev, r);
80*4882a593Smuzhiyun if (IS_ERR(reg))
81*4882a593Smuzhiyun return PTR_ERR(reg);
82*4882a593Smuzhiyun
83*4882a593Smuzhiyun clk = sunxi_factors_register(np, &sun6i_ar100_data, &sun6i_ar100_lock,
84*4882a593Smuzhiyun reg);
85*4882a593Smuzhiyun if (!clk)
86*4882a593Smuzhiyun return -ENOMEM;
87*4882a593Smuzhiyun
88*4882a593Smuzhiyun platform_set_drvdata(pdev, clk);
89*4882a593Smuzhiyun
90*4882a593Smuzhiyun return 0;
91*4882a593Smuzhiyun }
92*4882a593Smuzhiyun
93*4882a593Smuzhiyun static const struct of_device_id sun6i_a31_ar100_clk_dt_ids[] = {
94*4882a593Smuzhiyun { .compatible = "allwinner,sun6i-a31-ar100-clk" },
95*4882a593Smuzhiyun { /* sentinel */ }
96*4882a593Smuzhiyun };
97*4882a593Smuzhiyun
98*4882a593Smuzhiyun static struct platform_driver sun6i_a31_ar100_clk_driver = {
99*4882a593Smuzhiyun .driver = {
100*4882a593Smuzhiyun .name = "sun6i-a31-ar100-clk",
101*4882a593Smuzhiyun .of_match_table = sun6i_a31_ar100_clk_dt_ids,
102*4882a593Smuzhiyun .suppress_bind_attrs = true,
103*4882a593Smuzhiyun },
104*4882a593Smuzhiyun .probe = sun6i_a31_ar100_clk_probe,
105*4882a593Smuzhiyun };
106*4882a593Smuzhiyun builtin_platform_driver(sun6i_a31_ar100_clk_driver);
107