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11#include <linux/clk.h>
12#include <linux/clk-provider.h>
13#include <linux/cpu.h>
14#include <linux/cpufreq.h>
15#include <linux/delay.h>
16#include <linux/module.h>
17#include <linux/platform_device.h>
18#include <linux/slab.h>
19
20#include <cpufreq.h>
21#include <loongson1.h>
22
23static struct {
24 struct device *dev;
25 struct clk *clk;
26 struct clk *mux_clk;
27 struct clk *pll_clk;
28 struct clk *osc_clk;
29 unsigned int max_freq;
30 unsigned int min_freq;
31} ls1x_cpufreq;
32
33static int ls1x_cpufreq_notifier(struct notifier_block *nb,
34 unsigned long val, void *data)
35{
36 if (val == CPUFREQ_POSTCHANGE)
37 current_cpu_data.udelay_val = loops_per_jiffy;
38
39 return NOTIFY_OK;
40}
41
42static struct notifier_block ls1x_cpufreq_notifier_block = {
43 .notifier_call = ls1x_cpufreq_notifier
44};
45
46static int ls1x_cpufreq_target(struct cpufreq_policy *policy,
47 unsigned int index)
48{
49 unsigned int old_freq, new_freq;
50
51 old_freq = policy->cur;
52 new_freq = policy->freq_table[index].frequency;
53
54
55
56
57
58
59
60
61
62
63 dev_dbg(ls1x_cpufreq.dev, "%u KHz --> %u KHz\n", old_freq, new_freq);
64 clk_set_parent(policy->clk, ls1x_cpufreq.osc_clk);
65 __raw_writel(__raw_readl(LS1X_CLK_PLL_DIV) | RST_CPU_EN | RST_CPU,
66 LS1X_CLK_PLL_DIV);
67 __raw_writel(__raw_readl(LS1X_CLK_PLL_DIV) & ~(RST_CPU_EN | RST_CPU),
68 LS1X_CLK_PLL_DIV);
69 clk_set_rate(ls1x_cpufreq.mux_clk, new_freq * 1000);
70 clk_set_parent(policy->clk, ls1x_cpufreq.mux_clk);
71
72 return 0;
73}
74
75static int ls1x_cpufreq_init(struct cpufreq_policy *policy)
76{
77 struct cpufreq_frequency_table *freq_tbl;
78 unsigned int pll_freq, freq;
79 int steps, i, ret;
80
81 pll_freq = clk_get_rate(ls1x_cpufreq.pll_clk) / 1000;
82
83 steps = 1 << DIV_CPU_WIDTH;
84 freq_tbl = kzalloc(sizeof(*freq_tbl) * steps, GFP_KERNEL);
85 if (!freq_tbl) {
86 dev_err(ls1x_cpufreq.dev,
87 "failed to alloc cpufreq_frequency_table\n");
88 ret = -ENOMEM;
89 goto out;
90 }
91
92 for (i = 0; i < (steps - 1); i++) {
93 freq = pll_freq / (i + 1);
94 if ((freq < ls1x_cpufreq.min_freq) ||
95 (freq > ls1x_cpufreq.max_freq))
96 freq_tbl[i].frequency = CPUFREQ_ENTRY_INVALID;
97 else
98 freq_tbl[i].frequency = freq;
99 dev_dbg(ls1x_cpufreq.dev,
100 "cpufreq table: index %d: frequency %d\n", i,
101 freq_tbl[i].frequency);
102 }
103 freq_tbl[i].frequency = CPUFREQ_TABLE_END;
104
105 policy->clk = ls1x_cpufreq.clk;
106 ret = cpufreq_generic_init(policy, freq_tbl, 0);
107 if (ret)
108 kfree(freq_tbl);
109out:
110 return ret;
111}
112
113static int ls1x_cpufreq_exit(struct cpufreq_policy *policy)
114{
115 kfree(policy->freq_table);
116 return 0;
117}
118
119static struct cpufreq_driver ls1x_cpufreq_driver = {
120 .name = "cpufreq-ls1x",
121 .flags = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK,
122 .verify = cpufreq_generic_frequency_table_verify,
123 .target_index = ls1x_cpufreq_target,
124 .get = cpufreq_generic_get,
125 .init = ls1x_cpufreq_init,
126 .exit = ls1x_cpufreq_exit,
127 .attr = cpufreq_generic_attr,
128};
129
130static int ls1x_cpufreq_remove(struct platform_device *pdev)
131{
132 cpufreq_unregister_notifier(&ls1x_cpufreq_notifier_block,
133 CPUFREQ_TRANSITION_NOTIFIER);
134 cpufreq_unregister_driver(&ls1x_cpufreq_driver);
135
136 return 0;
137}
138
139static int ls1x_cpufreq_probe(struct platform_device *pdev)
140{
141 struct plat_ls1x_cpufreq *pdata = pdev->dev.platform_data;
142 struct clk *clk;
143 int ret;
144
145 if (!pdata || !pdata->clk_name || !pdata->osc_clk_name)
146 return -EINVAL;
147
148 ls1x_cpufreq.dev = &pdev->dev;
149
150 clk = devm_clk_get(&pdev->dev, pdata->clk_name);
151 if (IS_ERR(clk)) {
152 dev_err(ls1x_cpufreq.dev, "unable to get %s clock\n",
153 pdata->clk_name);
154 ret = PTR_ERR(clk);
155 goto out;
156 }
157 ls1x_cpufreq.clk = clk;
158
159 clk = clk_get_parent(clk);
160 if (IS_ERR(clk)) {
161 dev_err(ls1x_cpufreq.dev, "unable to get parent of %s clock\n",
162 __clk_get_name(ls1x_cpufreq.clk));
163 ret = PTR_ERR(clk);
164 goto out;
165 }
166 ls1x_cpufreq.mux_clk = clk;
167
168 clk = clk_get_parent(clk);
169 if (IS_ERR(clk)) {
170 dev_err(ls1x_cpufreq.dev, "unable to get parent of %s clock\n",
171 __clk_get_name(ls1x_cpufreq.mux_clk));
172 ret = PTR_ERR(clk);
173 goto out;
174 }
175 ls1x_cpufreq.pll_clk = clk;
176
177 clk = devm_clk_get(&pdev->dev, pdata->osc_clk_name);
178 if (IS_ERR(clk)) {
179 dev_err(ls1x_cpufreq.dev, "unable to get %s clock\n",
180 pdata->osc_clk_name);
181 ret = PTR_ERR(clk);
182 goto out;
183 }
184 ls1x_cpufreq.osc_clk = clk;
185
186 ls1x_cpufreq.max_freq = pdata->max_freq;
187 ls1x_cpufreq.min_freq = pdata->min_freq;
188
189 ret = cpufreq_register_driver(&ls1x_cpufreq_driver);
190 if (ret) {
191 dev_err(ls1x_cpufreq.dev,
192 "failed to register cpufreq driver: %d\n", ret);
193 goto out;
194 }
195
196 ret = cpufreq_register_notifier(&ls1x_cpufreq_notifier_block,
197 CPUFREQ_TRANSITION_NOTIFIER);
198
199 if (!ret)
200 goto out;
201
202 dev_err(ls1x_cpufreq.dev, "failed to register cpufreq notifier: %d\n",
203 ret);
204
205 cpufreq_unregister_driver(&ls1x_cpufreq_driver);
206out:
207 return ret;
208}
209
210static struct platform_driver ls1x_cpufreq_platdrv = {
211 .driver = {
212 .name = "ls1x-cpufreq",
213 },
214 .probe = ls1x_cpufreq_probe,
215 .remove = ls1x_cpufreq_remove,
216};
217
218module_platform_driver(ls1x_cpufreq_platdrv);
219
220MODULE_AUTHOR("Kelvin Cheung <keguang.zhang@gmail.com>");
221MODULE_DESCRIPTION("Loongson 1 CPUFreq driver");
222MODULE_LICENSE("GPL");
223
