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8#include <linux/clk-provider.h>
9#include <linux/device.h>
10#include <linux/err.h>
11#include <linux/of.h>
12#include <linux/module.h>
13#include <linux/scmi_protocol.h>
14#include <asm/div64.h>
15
16static const struct scmi_clk_proto_ops *scmi_proto_clk_ops;
17
18struct scmi_clk {
19 u32 id;
20 struct clk_hw hw;
21 const struct scmi_clock_info *info;
22 const struct scmi_protocol_handle *ph;
23};
24
25#define to_scmi_clk(clk) container_of(clk, struct scmi_clk, hw)
26
27static unsigned long scmi_clk_recalc_rate(struct clk_hw *hw,
28 unsigned long parent_rate)
29{
30 int ret;
31 u64 rate;
32 struct scmi_clk *clk = to_scmi_clk(hw);
33
34 ret = scmi_proto_clk_ops->rate_get(clk->ph, clk->id, &rate);
35 if (ret)
36 return 0;
37 return rate;
38}
39
40static long scmi_clk_round_rate(struct clk_hw *hw, unsigned long rate,
41 unsigned long *parent_rate)
42{
43 u64 fmin, fmax, ftmp;
44 struct scmi_clk *clk = to_scmi_clk(hw);
45
46
47
48
49
50
51
52 if (clk->info->rate_discrete)
53 return rate;
54
55 fmin = clk->info->range.min_rate;
56 fmax = clk->info->range.max_rate;
57 if (rate <= fmin)
58 return fmin;
59 else if (rate >= fmax)
60 return fmax;
61
62 ftmp = rate - fmin;
63 ftmp += clk->info->range.step_size - 1;
64 do_div(ftmp, clk->info->range.step_size);
65
66 return ftmp * clk->info->range.step_size + fmin;
67}
68
69static int scmi_clk_set_rate(struct clk_hw *hw, unsigned long rate,
70 unsigned long parent_rate)
71{
72 struct scmi_clk *clk = to_scmi_clk(hw);
73
74 return scmi_proto_clk_ops->rate_set(clk->ph, clk->id, rate);
75}
76
77static int scmi_clk_enable(struct clk_hw *hw)
78{
79 struct scmi_clk *clk = to_scmi_clk(hw);
80
81 return scmi_proto_clk_ops->enable(clk->ph, clk->id);
82}
83
84static void scmi_clk_disable(struct clk_hw *hw)
85{
86 struct scmi_clk *clk = to_scmi_clk(hw);
87
88 scmi_proto_clk_ops->disable(clk->ph, clk->id);
89}
90
91static const struct clk_ops scmi_clk_ops = {
92 .recalc_rate = scmi_clk_recalc_rate,
93 .round_rate = scmi_clk_round_rate,
94 .set_rate = scmi_clk_set_rate,
95
96
97
98
99
100
101 .prepare = scmi_clk_enable,
102 .unprepare = scmi_clk_disable,
103};
104
105static int scmi_clk_ops_init(struct device *dev, struct scmi_clk *sclk)
106{
107 int ret;
108 unsigned long min_rate, max_rate;
109
110 struct clk_init_data init = {
111 .flags = CLK_GET_RATE_NOCACHE,
112 .num_parents = 0,
113 .ops = &scmi_clk_ops,
114 .name = sclk->info->name,
115 };
116
117 sclk->hw.init = &init;
118 ret = devm_clk_hw_register(dev, &sclk->hw);
119 if (ret)
120 return ret;
121
122 if (sclk->info->rate_discrete) {
123 int num_rates = sclk->info->list.num_rates;
124
125 if (num_rates <= 0)
126 return -EINVAL;
127
128 min_rate = sclk->info->list.rates[0];
129 max_rate = sclk->info->list.rates[num_rates - 1];
130 } else {
131 min_rate = sclk->info->range.min_rate;
132 max_rate = sclk->info->range.max_rate;
133 }
134
135 clk_hw_set_rate_range(&sclk->hw, min_rate, max_rate);
136 return ret;
137}
138
139static int scmi_clocks_probe(struct scmi_device *sdev)
140{
141 int idx, count, err;
142 struct clk_hw **hws;
143 struct clk_hw_onecell_data *clk_data;
144 struct device *dev = &sdev->dev;
145 struct device_node *np = dev->of_node;
146 const struct scmi_handle *handle = sdev->handle;
147 struct scmi_protocol_handle *ph;
148
149 if (!handle)
150 return -ENODEV;
151
152 scmi_proto_clk_ops =
153 handle->devm_protocol_get(sdev, SCMI_PROTOCOL_CLOCK, &ph);
154 if (IS_ERR(scmi_proto_clk_ops))
155 return PTR_ERR(scmi_proto_clk_ops);
156
157 count = scmi_proto_clk_ops->count_get(ph);
158 if (count < 0) {
159 dev_err(dev, "%pOFn: invalid clock output count\n", np);
160 return -EINVAL;
161 }
162
163 clk_data = devm_kzalloc(dev, struct_size(clk_data, hws, count),
164 GFP_KERNEL);
165 if (!clk_data)
166 return -ENOMEM;
167
168 clk_data->num = count;
169 hws = clk_data->hws;
170
171 for (idx = 0; idx < count; idx++) {
172 struct scmi_clk *sclk;
173
174 sclk = devm_kzalloc(dev, sizeof(*sclk), GFP_KERNEL);
175 if (!sclk)
176 return -ENOMEM;
177
178 sclk->info = scmi_proto_clk_ops->info_get(ph, idx);
179 if (!sclk->info) {
180 dev_dbg(dev, "invalid clock info for idx %d\n", idx);
181 continue;
182 }
183
184 sclk->id = idx;
185 sclk->ph = ph;
186
187 err = scmi_clk_ops_init(dev, sclk);
188 if (err) {
189 dev_err(dev, "failed to register clock %d\n", idx);
190 devm_kfree(dev, sclk);
191 hws[idx] = NULL;
192 } else {
193 dev_dbg(dev, "Registered clock:%s\n", sclk->info->name);
194 hws[idx] = &sclk->hw;
195 }
196 }
197
198 return devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get,
199 clk_data);
200}
201
202static const struct scmi_device_id scmi_id_table[] = {
203 { SCMI_PROTOCOL_CLOCK, "clocks" },
204 { },
205};
206MODULE_DEVICE_TABLE(scmi, scmi_id_table);
207
208static struct scmi_driver scmi_clocks_driver = {
209 .name = "scmi-clocks",
210 .probe = scmi_clocks_probe,
211 .id_table = scmi_id_table,
212};
213module_scmi_driver(scmi_clocks_driver);
214
215MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
216MODULE_DESCRIPTION("ARM SCMI clock driver");
217MODULE_LICENSE("GPL v2");
218
