1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * Copyright (C) 2007 PA Semi, Inc |
4 | * |
5 | * Authors: Egor Martovetsky <egor@pasemi.com> |
6 | * Olof Johansson <olof@lixom.net> |
7 | * |
8 | * Maintained by: Olof Johansson <olof@lixom.net> |
9 | * |
10 | * Based on arch/powerpc/platforms/cell/cbe_cpufreq.c: |
11 | * (C) Copyright IBM Deutschland Entwicklung GmbH 2005 |
12 | */ |
13 | |
14 | #include <linux/cpufreq.h> |
15 | #include <linux/timer.h> |
16 | #include <linux/module.h> |
17 | #include <linux/of_address.h> |
18 | |
19 | #include <asm/hw_irq.h> |
20 | #include <asm/io.h> |
21 | #include <asm/time.h> |
22 | #include <asm/smp.h> |
23 | |
24 | #include <platforms/pasemi/pasemi.h> |
25 | |
26 | #define SDCASR_REG 0x0100 |
27 | #define SDCASR_REG_STRIDE 0x1000 |
28 | #define SDCPWR_CFGA0_REG 0x0100 |
29 | #define SDCPWR_PWST0_REG 0x0000 |
30 | #define SDCPWR_GIZTIME_REG 0x0440 |
31 | |
32 | /* SDCPWR_GIZTIME_REG fields */ |
33 | #define SDCPWR_GIZTIME_GR 0x80000000 |
34 | #define SDCPWR_GIZTIME_LONGLOCK 0x000000ff |
35 | |
36 | /* Offset of ASR registers from SDC base */ |
37 | #define SDCASR_OFFSET 0x120000 |
38 | |
39 | static void __iomem *sdcpwr_mapbase; |
40 | static void __iomem *sdcasr_mapbase; |
41 | |
42 | /* Current astate, is used when waking up from power savings on |
43 | * one core, in case the other core has switched states during |
44 | * the idle time. |
45 | */ |
46 | static int current_astate; |
47 | |
48 | /* We support 5(A0-A4) power states excluding turbo(A5-A6) modes */ |
49 | static struct cpufreq_frequency_table pas_freqs[] = { |
50 | {0, 0, 0}, |
51 | {0, 1, 0}, |
52 | {0, 2, 0}, |
53 | {0, 3, 0}, |
54 | {0, 4, 0}, |
55 | {0, 0, CPUFREQ_TABLE_END}, |
56 | }; |
57 | |
58 | /* |
59 | * hardware specific functions |
60 | */ |
61 | |
62 | static int get_astate_freq(int astate) |
63 | { |
64 | u32 ret; |
65 | ret = in_le32(sdcpwr_mapbase + SDCPWR_CFGA0_REG + (astate * 0x10)); |
66 | |
67 | return ret & 0x3f; |
68 | } |
69 | |
70 | static int get_cur_astate(int cpu) |
71 | { |
72 | u32 ret; |
73 | |
74 | ret = in_le32(sdcpwr_mapbase + SDCPWR_PWST0_REG); |
75 | ret = (ret >> (cpu * 4)) & 0x7; |
76 | |
77 | return ret; |
78 | } |
79 | |
80 | static int get_gizmo_latency(void) |
81 | { |
82 | u32 giztime, ret; |
83 | |
84 | giztime = in_le32(sdcpwr_mapbase + SDCPWR_GIZTIME_REG); |
85 | |
86 | /* just provide the upper bound */ |
87 | if (giztime & SDCPWR_GIZTIME_GR) |
88 | ret = (giztime & SDCPWR_GIZTIME_LONGLOCK) * 128000; |
89 | else |
90 | ret = (giztime & SDCPWR_GIZTIME_LONGLOCK) * 1000; |
91 | |
92 | return ret; |
93 | } |
94 | |
95 | static void set_astate(int cpu, unsigned int astate) |
96 | { |
97 | unsigned long flags; |
98 | |
99 | /* Return if called before init has run */ |
100 | if (unlikely(!sdcasr_mapbase)) |
101 | return; |
102 | |
103 | local_irq_save(flags); |
104 | |
105 | out_le32(sdcasr_mapbase + SDCASR_REG + SDCASR_REG_STRIDE*cpu, astate); |
106 | |
107 | local_irq_restore(flags); |
108 | } |
109 | |
110 | int check_astate(void) |
111 | { |
112 | return get_cur_astate(cpu: hard_smp_processor_id()); |
113 | } |
114 | |
115 | void restore_astate(int cpu) |
116 | { |
117 | set_astate(cpu, astate: current_astate); |
118 | } |
119 | |
120 | /* |
121 | * cpufreq functions |
122 | */ |
123 | |
124 | static int pas_cpufreq_cpu_init(struct cpufreq_policy *policy) |
125 | { |
126 | struct cpufreq_frequency_table *pos; |
127 | const u32 *max_freqp; |
128 | u32 max_freq; |
129 | int cur_astate, idx; |
130 | struct resource res; |
131 | struct device_node *cpu, *dn; |
132 | int err = -ENODEV; |
133 | |
134 | cpu = of_get_cpu_node(cpu: policy->cpu, NULL); |
135 | if (!cpu) |
136 | goto out; |
137 | |
138 | max_freqp = of_get_property(node: cpu, name: "clock-frequency" , NULL); |
139 | of_node_put(node: cpu); |
140 | if (!max_freqp) { |
141 | err = -EINVAL; |
142 | goto out; |
143 | } |
144 | |
145 | /* we need the freq in kHz */ |
146 | max_freq = *max_freqp / 1000; |
147 | |
148 | dn = of_find_compatible_node(NULL, NULL, compat: "1682m-sdc" ); |
149 | if (!dn) |
150 | dn = of_find_compatible_node(NULL, NULL, |
151 | compat: "pasemi,pwrficient-sdc" ); |
152 | if (!dn) |
153 | goto out; |
154 | err = of_address_to_resource(dev: dn, index: 0, r: &res); |
155 | of_node_put(node: dn); |
156 | if (err) |
157 | goto out; |
158 | sdcasr_mapbase = ioremap(offset: res.start + SDCASR_OFFSET, size: 0x2000); |
159 | if (!sdcasr_mapbase) { |
160 | err = -EINVAL; |
161 | goto out; |
162 | } |
163 | |
164 | dn = of_find_compatible_node(NULL, NULL, compat: "1682m-gizmo" ); |
165 | if (!dn) |
166 | dn = of_find_compatible_node(NULL, NULL, |
167 | compat: "pasemi,pwrficient-gizmo" ); |
168 | if (!dn) { |
169 | err = -ENODEV; |
170 | goto out_unmap_sdcasr; |
171 | } |
172 | err = of_address_to_resource(dev: dn, index: 0, r: &res); |
173 | of_node_put(node: dn); |
174 | if (err) |
175 | goto out_unmap_sdcasr; |
176 | sdcpwr_mapbase = ioremap(offset: res.start, size: 0x1000); |
177 | if (!sdcpwr_mapbase) { |
178 | err = -EINVAL; |
179 | goto out_unmap_sdcasr; |
180 | } |
181 | |
182 | pr_debug("init cpufreq on CPU %d\n" , policy->cpu); |
183 | pr_debug("max clock-frequency is at %u kHz\n" , max_freq); |
184 | pr_debug("initializing frequency table\n" ); |
185 | |
186 | /* initialize frequency table */ |
187 | cpufreq_for_each_entry_idx(pos, pas_freqs, idx) { |
188 | pos->frequency = get_astate_freq(astate: pos->driver_data) * 100000; |
189 | pr_debug("%d: %d\n" , idx, pos->frequency); |
190 | } |
191 | |
192 | cur_astate = get_cur_astate(cpu: policy->cpu); |
193 | pr_debug("current astate is at %d\n" ,cur_astate); |
194 | |
195 | policy->cur = pas_freqs[cur_astate].frequency; |
196 | ppc_proc_freq = policy->cur * 1000ul; |
197 | |
198 | cpufreq_generic_init(policy, table: pas_freqs, transition_latency: get_gizmo_latency()); |
199 | return 0; |
200 | |
201 | out_unmap_sdcasr: |
202 | iounmap(addr: sdcasr_mapbase); |
203 | out: |
204 | return err; |
205 | } |
206 | |
207 | static int pas_cpufreq_cpu_exit(struct cpufreq_policy *policy) |
208 | { |
209 | /* |
210 | * We don't support CPU hotplug. Don't unmap after the system |
211 | * has already made it to a running state. |
212 | */ |
213 | if (system_state >= SYSTEM_RUNNING) |
214 | return 0; |
215 | |
216 | if (sdcasr_mapbase) |
217 | iounmap(addr: sdcasr_mapbase); |
218 | if (sdcpwr_mapbase) |
219 | iounmap(addr: sdcpwr_mapbase); |
220 | |
221 | return 0; |
222 | } |
223 | |
224 | static int pas_cpufreq_target(struct cpufreq_policy *policy, |
225 | unsigned int pas_astate_new) |
226 | { |
227 | int i; |
228 | |
229 | pr_debug("setting frequency for cpu %d to %d kHz, 1/%d of max frequency\n" , |
230 | policy->cpu, |
231 | pas_freqs[pas_astate_new].frequency, |
232 | pas_freqs[pas_astate_new].driver_data); |
233 | |
234 | current_astate = pas_astate_new; |
235 | |
236 | for_each_online_cpu(i) |
237 | set_astate(cpu: i, astate: pas_astate_new); |
238 | |
239 | ppc_proc_freq = pas_freqs[pas_astate_new].frequency * 1000ul; |
240 | return 0; |
241 | } |
242 | |
243 | static struct cpufreq_driver pas_cpufreq_driver = { |
244 | .name = "pas-cpufreq" , |
245 | .flags = CPUFREQ_CONST_LOOPS, |
246 | .init = pas_cpufreq_cpu_init, |
247 | .exit = pas_cpufreq_cpu_exit, |
248 | .verify = cpufreq_generic_frequency_table_verify, |
249 | .target_index = pas_cpufreq_target, |
250 | .attr = cpufreq_generic_attr, |
251 | }; |
252 | |
253 | /* |
254 | * module init and destoy |
255 | */ |
256 | |
257 | static int __init pas_cpufreq_init(void) |
258 | { |
259 | if (!of_machine_is_compatible(compat: "PA6T-1682M" ) && |
260 | !of_machine_is_compatible(compat: "pasemi,pwrficient" )) |
261 | return -ENODEV; |
262 | |
263 | return cpufreq_register_driver(driver_data: &pas_cpufreq_driver); |
264 | } |
265 | |
266 | static void __exit pas_cpufreq_exit(void) |
267 | { |
268 | cpufreq_unregister_driver(driver_data: &pas_cpufreq_driver); |
269 | } |
270 | |
271 | module_init(pas_cpufreq_init); |
272 | module_exit(pas_cpufreq_exit); |
273 | |
274 | MODULE_LICENSE("GPL" ); |
275 | MODULE_AUTHOR("Egor Martovetsky <egor@pasemi.com>, Olof Johansson <olof@lixom.net>" ); |
276 | |