Commit | Line | Data |
---|---|---|
2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2a4bd9f0 AL |
2 | /* |
3 | * kirkwood_freq.c: cpufreq driver for the Marvell kirkwood | |
4 | * | |
5 | * Copyright (C) 2013 Andrew Lunn <andrew@lunn.ch> | |
2a4bd9f0 AL |
6 | */ |
7 | ||
8 | #include <linux/kernel.h> | |
9 | #include <linux/module.h> | |
10 | #include <linux/clk.h> | |
2a4bd9f0 | 11 | #include <linux/cpufreq.h> |
e768f350 | 12 | #include <linux/of_device.h> |
2a4bd9f0 AL |
13 | #include <linux/platform_device.h> |
14 | #include <linux/io.h> | |
15 | #include <asm/proc-fns.h> | |
16 | ||
17 | #define CPU_SW_INT_BLK BIT(28) | |
18 | ||
19 | static struct priv | |
20 | { | |
21 | struct clk *cpu_clk; | |
22 | struct clk *ddr_clk; | |
23 | struct clk *powersave_clk; | |
24 | struct device *dev; | |
25 | void __iomem *base; | |
26 | } priv; | |
27 | ||
28 | #define STATE_CPU_FREQ 0x01 | |
29 | #define STATE_DDR_FREQ 0x02 | |
30 | ||
31 | /* | |
32 | * Kirkwood can swap the clock to the CPU between two clocks: | |
33 | * | |
34 | * - cpu clk | |
35 | * - ddr clk | |
36 | * | |
10529938 | 37 | * The frequencies are set at runtime before registering this table. |
2a4bd9f0 AL |
38 | */ |
39 | static struct cpufreq_frequency_table kirkwood_freq_table[] = { | |
7f4b0461 VK |
40 | {0, STATE_CPU_FREQ, 0}, /* CPU uses cpuclk */ |
41 | {0, STATE_DDR_FREQ, 0}, /* CPU uses ddrclk */ | |
42 | {0, 0, CPUFREQ_TABLE_END}, | |
2a4bd9f0 AL |
43 | }; |
44 | ||
45 | static unsigned int kirkwood_cpufreq_get_cpu_frequency(unsigned int cpu) | |
46 | { | |
10529938 | 47 | return clk_get_rate(priv.powersave_clk) / 1000; |
2a4bd9f0 AL |
48 | } |
49 | ||
9c0ebcf7 VK |
50 | static int kirkwood_cpufreq_target(struct cpufreq_policy *policy, |
51 | unsigned int index) | |
2a4bd9f0 | 52 | { |
50701588 | 53 | unsigned int state = kirkwood_freq_table[index].driver_data; |
2a4bd9f0 AL |
54 | unsigned long reg; |
55 | ||
d4019f0a | 56 | local_irq_disable(); |
2a4bd9f0 | 57 | |
d4019f0a VK |
58 | /* Disable interrupts to the CPU */ |
59 | reg = readl_relaxed(priv.base); | |
60 | reg |= CPU_SW_INT_BLK; | |
61 | writel_relaxed(reg, priv.base); | |
2a4bd9f0 | 62 | |
d4019f0a VK |
63 | switch (state) { |
64 | case STATE_CPU_FREQ: | |
10529938 | 65 | clk_set_parent(priv.powersave_clk, priv.cpu_clk); |
d4019f0a VK |
66 | break; |
67 | case STATE_DDR_FREQ: | |
10529938 | 68 | clk_set_parent(priv.powersave_clk, priv.ddr_clk); |
d4019f0a VK |
69 | break; |
70 | } | |
2a4bd9f0 | 71 | |
d4019f0a VK |
72 | /* Wait-for-Interrupt, while the hardware changes frequency */ |
73 | cpu_do_idle(); | |
2a4bd9f0 | 74 | |
d4019f0a VK |
75 | /* Enable interrupts to the CPU */ |
76 | reg = readl_relaxed(priv.base); | |
77 | reg &= ~CPU_SW_INT_BLK; | |
78 | writel_relaxed(reg, priv.base); | |
2a4bd9f0 | 79 | |
d4019f0a | 80 | local_irq_enable(); |
2a4bd9f0 AL |
81 | |
82 | return 0; | |
83 | } | |
84 | ||
85 | /* Module init and exit code */ | |
86 | static int kirkwood_cpufreq_cpu_init(struct cpufreq_policy *policy) | |
87 | { | |
c4dcc8a1 VK |
88 | cpufreq_generic_init(policy, kirkwood_freq_table, 5000); |
89 | return 0; | |
2a4bd9f0 AL |
90 | } |
91 | ||
2a4bd9f0 | 92 | static struct cpufreq_driver kirkwood_cpufreq_driver = { |
ae6b4271 | 93 | .flags = CPUFREQ_NEED_INITIAL_FREQ_CHECK, |
2a4bd9f0 | 94 | .get = kirkwood_cpufreq_get_cpu_frequency, |
a86a41a1 | 95 | .verify = cpufreq_generic_frequency_table_verify, |
9c0ebcf7 | 96 | .target_index = kirkwood_cpufreq_target, |
2a4bd9f0 | 97 | .init = kirkwood_cpufreq_cpu_init, |
2a4bd9f0 | 98 | .name = "kirkwood-cpufreq", |
a86a41a1 | 99 | .attr = cpufreq_generic_attr, |
2a4bd9f0 AL |
100 | }; |
101 | ||
102 | static int kirkwood_cpufreq_probe(struct platform_device *pdev) | |
103 | { | |
104 | struct device_node *np; | |
2a4bd9f0 AL |
105 | int err; |
106 | ||
107 | priv.dev = &pdev->dev; | |
108 | ||
af9c8e91 | 109 | priv.base = devm_platform_ioremap_resource(pdev, 0); |
cc721c4f SMP |
110 | if (IS_ERR(priv.base)) |
111 | return PTR_ERR(priv.base); | |
2a4bd9f0 | 112 | |
e768f350 SK |
113 | np = of_cpu_device_node_get(0); |
114 | if (!np) { | |
115 | dev_err(&pdev->dev, "failed to get cpu device node\n"); | |
2a4bd9f0 | 116 | return -ENODEV; |
e768f350 | 117 | } |
2a4bd9f0 AL |
118 | |
119 | priv.cpu_clk = of_clk_get_by_name(np, "cpu_clk"); | |
120 | if (IS_ERR(priv.cpu_clk)) { | |
4c232f94 | 121 | dev_err(priv.dev, "Unable to get cpuclk\n"); |
7c468966 WY |
122 | err = PTR_ERR(priv.cpu_clk); |
123 | goto out_node; | |
2a4bd9f0 AL |
124 | } |
125 | ||
7575f825 AY |
126 | err = clk_prepare_enable(priv.cpu_clk); |
127 | if (err) { | |
128 | dev_err(priv.dev, "Unable to prepare cpuclk\n"); | |
7c468966 | 129 | goto out_node; |
7575f825 AY |
130 | } |
131 | ||
2a4bd9f0 AL |
132 | kirkwood_freq_table[0].frequency = clk_get_rate(priv.cpu_clk) / 1000; |
133 | ||
134 | priv.ddr_clk = of_clk_get_by_name(np, "ddrclk"); | |
135 | if (IS_ERR(priv.ddr_clk)) { | |
4c232f94 | 136 | dev_err(priv.dev, "Unable to get ddrclk\n"); |
2a4bd9f0 AL |
137 | err = PTR_ERR(priv.ddr_clk); |
138 | goto out_cpu; | |
139 | } | |
140 | ||
7575f825 AY |
141 | err = clk_prepare_enable(priv.ddr_clk); |
142 | if (err) { | |
143 | dev_err(priv.dev, "Unable to prepare ddrclk\n"); | |
144 | goto out_cpu; | |
145 | } | |
2a4bd9f0 AL |
146 | kirkwood_freq_table[1].frequency = clk_get_rate(priv.ddr_clk) / 1000; |
147 | ||
148 | priv.powersave_clk = of_clk_get_by_name(np, "powersave"); | |
149 | if (IS_ERR(priv.powersave_clk)) { | |
4c232f94 | 150 | dev_err(priv.dev, "Unable to get powersave\n"); |
2a4bd9f0 AL |
151 | err = PTR_ERR(priv.powersave_clk); |
152 | goto out_ddr; | |
153 | } | |
7575f825 AY |
154 | err = clk_prepare_enable(priv.powersave_clk); |
155 | if (err) { | |
156 | dev_err(priv.dev, "Unable to prepare powersave clk\n"); | |
157 | goto out_ddr; | |
158 | } | |
2a4bd9f0 | 159 | |
2a4bd9f0 | 160 | err = cpufreq_register_driver(&kirkwood_cpufreq_driver); |
7c468966 WY |
161 | if (err) { |
162 | dev_err(priv.dev, "Failed to register cpufreq driver\n"); | |
163 | goto out_powersave; | |
164 | } | |
2a4bd9f0 | 165 | |
7c468966 WY |
166 | of_node_put(np); |
167 | return 0; | |
2a4bd9f0 | 168 | |
7c468966 | 169 | out_powersave: |
2a4bd9f0 AL |
170 | clk_disable_unprepare(priv.powersave_clk); |
171 | out_ddr: | |
172 | clk_disable_unprepare(priv.ddr_clk); | |
173 | out_cpu: | |
174 | clk_disable_unprepare(priv.cpu_clk); | |
7c468966 | 175 | out_node: |
2a4bd9f0 AL |
176 | of_node_put(np); |
177 | ||
178 | return err; | |
179 | } | |
180 | ||
181 | static int kirkwood_cpufreq_remove(struct platform_device *pdev) | |
182 | { | |
183 | cpufreq_unregister_driver(&kirkwood_cpufreq_driver); | |
184 | ||
185 | clk_disable_unprepare(priv.powersave_clk); | |
186 | clk_disable_unprepare(priv.ddr_clk); | |
187 | clk_disable_unprepare(priv.cpu_clk); | |
188 | ||
189 | return 0; | |
190 | } | |
191 | ||
192 | static struct platform_driver kirkwood_cpufreq_platform_driver = { | |
193 | .probe = kirkwood_cpufreq_probe, | |
194 | .remove = kirkwood_cpufreq_remove, | |
195 | .driver = { | |
196 | .name = "kirkwood-cpufreq", | |
2a4bd9f0 AL |
197 | }, |
198 | }; | |
199 | ||
200 | module_platform_driver(kirkwood_cpufreq_platform_driver); | |
201 | ||
202 | MODULE_LICENSE("GPL v2"); | |
203 | MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch"); | |
204 | MODULE_DESCRIPTION("cpufreq driver for Marvell's kirkwood CPU"); | |
205 | MODULE_ALIAS("platform:kirkwood-cpufreq"); |