treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157
[sfrench/cifs-2.6.git] / drivers / clk / hisilicon / clk-hi3660-stub.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Hisilicon clock driver
4  *
5  * Copyright (c) 2013-2017 Hisilicon Limited.
6  * Copyright (c) 2017 Linaro Limited.
7  *
8  * Author: Kai Zhao <zhaokai1@hisilicon.com>
9  *          Tao Wang <kevin.wangtao@hisilicon.com>
10  *          Leo Yan <leo.yan@linaro.org>
11  */
12
13 #include <linux/clk-provider.h>
14 #include <linux/device.h>
15 #include <linux/err.h>
16 #include <linux/init.h>
17 #include <linux/io.h>
18 #include <linux/mailbox_client.h>
19 #include <linux/module.h>
20 #include <linux/of.h>
21 #include <linux/platform_device.h>
22 #include <dt-bindings/clock/hi3660-clock.h>
23
24 #define HI3660_STUB_CLOCK_DATA          (0x70)
25 #define MHZ                             (1000 * 1000)
26
27 #define DEFINE_CLK_STUB(_id, _cmd, _name)                       \
28         {                                                       \
29                 .id = (_id),                                    \
30                 .cmd = (_cmd),                                  \
31                 .hw.init = &(struct clk_init_data) {            \
32                         .name = #_name,                         \
33                         .ops = &hi3660_stub_clk_ops,            \
34                         .num_parents = 0,                       \
35                         .flags = CLK_GET_RATE_NOCACHE,          \
36                 },                                              \
37         },
38
39 #define to_stub_clk(_hw) container_of(_hw, struct hi3660_stub_clk, hw)
40
41 struct hi3660_stub_clk_chan {
42         struct mbox_client cl;
43         struct mbox_chan *mbox;
44 };
45
46 struct hi3660_stub_clk {
47         unsigned int id;
48         struct clk_hw hw;
49         unsigned int cmd;
50         unsigned int msg[8];
51         unsigned int rate;
52 };
53
54 static void __iomem *freq_reg;
55 static struct hi3660_stub_clk_chan stub_clk_chan;
56
57 static unsigned long hi3660_stub_clk_recalc_rate(struct clk_hw *hw,
58                                                  unsigned long parent_rate)
59 {
60         struct hi3660_stub_clk *stub_clk = to_stub_clk(hw);
61
62         /*
63          * LPM3 writes back the CPU frequency in shared SRAM so read
64          * back the frequency.
65          */
66         stub_clk->rate = readl(freq_reg + (stub_clk->id << 2)) * MHZ;
67         return stub_clk->rate;
68 }
69
70 static long hi3660_stub_clk_round_rate(struct clk_hw *hw, unsigned long rate,
71                                        unsigned long *prate)
72 {
73         /*
74          * LPM3 handles rate rounding so just return whatever
75          * rate is requested.
76          */
77         return rate;
78 }
79
80 static int hi3660_stub_clk_set_rate(struct clk_hw *hw, unsigned long rate,
81                                     unsigned long parent_rate)
82 {
83         struct hi3660_stub_clk *stub_clk = to_stub_clk(hw);
84
85         stub_clk->msg[0] = stub_clk->cmd;
86         stub_clk->msg[1] = rate / MHZ;
87
88         dev_dbg(stub_clk_chan.cl.dev, "set rate msg[0]=0x%x msg[1]=0x%x\n",
89                 stub_clk->msg[0], stub_clk->msg[1]);
90
91         mbox_send_message(stub_clk_chan.mbox, stub_clk->msg);
92         mbox_client_txdone(stub_clk_chan.mbox, 0);
93
94         stub_clk->rate = rate;
95         return 0;
96 }
97
98 static const struct clk_ops hi3660_stub_clk_ops = {
99         .recalc_rate    = hi3660_stub_clk_recalc_rate,
100         .round_rate     = hi3660_stub_clk_round_rate,
101         .set_rate       = hi3660_stub_clk_set_rate,
102 };
103
104 static struct hi3660_stub_clk hi3660_stub_clks[HI3660_CLK_STUB_NUM] = {
105         DEFINE_CLK_STUB(HI3660_CLK_STUB_CLUSTER0, 0x0001030A, "cpu-cluster.0")
106         DEFINE_CLK_STUB(HI3660_CLK_STUB_CLUSTER1, 0x0002030A, "cpu-cluster.1")
107         DEFINE_CLK_STUB(HI3660_CLK_STUB_GPU, 0x0003030A, "clk-g3d")
108         DEFINE_CLK_STUB(HI3660_CLK_STUB_DDR, 0x00040309, "clk-ddrc")
109 };
110
111 static struct clk_hw *hi3660_stub_clk_hw_get(struct of_phandle_args *clkspec,
112                                              void *data)
113 {
114         unsigned int idx = clkspec->args[0];
115
116         if (idx >= HI3660_CLK_STUB_NUM) {
117                 pr_err("%s: invalid index %u\n", __func__, idx);
118                 return ERR_PTR(-EINVAL);
119         }
120
121         return &hi3660_stub_clks[idx].hw;
122 }
123
124 static int hi3660_stub_clk_probe(struct platform_device *pdev)
125 {
126         struct device *dev = &pdev->dev;
127         struct resource *res;
128         unsigned int i;
129         int ret;
130
131         /* Use mailbox client without blocking */
132         stub_clk_chan.cl.dev = dev;
133         stub_clk_chan.cl.tx_done = NULL;
134         stub_clk_chan.cl.tx_block = false;
135         stub_clk_chan.cl.knows_txdone = false;
136
137         /* Allocate mailbox channel */
138         stub_clk_chan.mbox = mbox_request_channel(&stub_clk_chan.cl, 0);
139         if (IS_ERR(stub_clk_chan.mbox))
140                 return PTR_ERR(stub_clk_chan.mbox);
141
142         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
143         if (!res)
144                 return -EINVAL;
145         freq_reg = devm_ioremap(dev, res->start, resource_size(res));
146         if (!freq_reg)
147                 return -ENOMEM;
148
149         freq_reg += HI3660_STUB_CLOCK_DATA;
150
151         for (i = 0; i < HI3660_CLK_STUB_NUM; i++) {
152                 ret = devm_clk_hw_register(&pdev->dev, &hi3660_stub_clks[i].hw);
153                 if (ret)
154                         return ret;
155         }
156
157         return devm_of_clk_add_hw_provider(&pdev->dev, hi3660_stub_clk_hw_get,
158                                            hi3660_stub_clks);
159 }
160
161 static const struct of_device_id hi3660_stub_clk_of_match[] = {
162         { .compatible = "hisilicon,hi3660-stub-clk", },
163         {}
164 };
165
166 static struct platform_driver hi3660_stub_clk_driver = {
167         .probe  = hi3660_stub_clk_probe,
168         .driver = {
169                 .name = "hi3660-stub-clk",
170                 .of_match_table = hi3660_stub_clk_of_match,
171         },
172 };
173
174 static int __init hi3660_stub_clk_init(void)
175 {
176         return platform_driver_register(&hi3660_stub_clk_driver);
177 }
178 subsys_initcall(hi3660_stub_clk_init);