dt-bindings: can: flexcan: list supported processors
[linux-2.6-microblaze.git] / drivers / cpufreq / pasemi-cpufreq.c
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/prom.h>
22 #include <asm/time.h>
23 #include <asm/smp.h>
24
25 #include <platforms/pasemi/pasemi.h>
26
27 #define SDCASR_REG              0x0100
28 #define SDCASR_REG_STRIDE       0x1000
29 #define SDCPWR_CFGA0_REG        0x0100
30 #define SDCPWR_PWST0_REG        0x0000
31 #define SDCPWR_GIZTIME_REG      0x0440
32
33 /* SDCPWR_GIZTIME_REG fields */
34 #define SDCPWR_GIZTIME_GR       0x80000000
35 #define SDCPWR_GIZTIME_LONGLOCK 0x000000ff
36
37 /* Offset of ASR registers from SDC base */
38 #define SDCASR_OFFSET           0x120000
39
40 static void __iomem *sdcpwr_mapbase;
41 static void __iomem *sdcasr_mapbase;
42
43 /* Current astate, is used when waking up from power savings on
44  * one core, in case the other core has switched states during
45  * the idle time.
46  */
47 static int current_astate;
48
49 /* We support 5(A0-A4) power states excluding turbo(A5-A6) modes */
50 static struct cpufreq_frequency_table pas_freqs[] = {
51         {0, 0,  0},
52         {0, 1,  0},
53         {0, 2,  0},
54         {0, 3,  0},
55         {0, 4,  0},
56         {0, 0,  CPUFREQ_TABLE_END},
57 };
58
59 /*
60  * hardware specific functions
61  */
62
63 static int get_astate_freq(int astate)
64 {
65         u32 ret;
66         ret = in_le32(sdcpwr_mapbase + SDCPWR_CFGA0_REG + (astate * 0x10));
67
68         return ret & 0x3f;
69 }
70
71 static int get_cur_astate(int cpu)
72 {
73         u32 ret;
74
75         ret = in_le32(sdcpwr_mapbase + SDCPWR_PWST0_REG);
76         ret = (ret >> (cpu * 4)) & 0x7;
77
78         return ret;
79 }
80
81 static int get_gizmo_latency(void)
82 {
83         u32 giztime, ret;
84
85         giztime = in_le32(sdcpwr_mapbase + SDCPWR_GIZTIME_REG);
86
87         /* just provide the upper bound */
88         if (giztime & SDCPWR_GIZTIME_GR)
89                 ret = (giztime & SDCPWR_GIZTIME_LONGLOCK) * 128000;
90         else
91                 ret = (giztime & SDCPWR_GIZTIME_LONGLOCK) * 1000;
92
93         return ret;
94 }
95
96 static void set_astate(int cpu, unsigned int astate)
97 {
98         unsigned long flags;
99
100         /* Return if called before init has run */
101         if (unlikely(!sdcasr_mapbase))
102                 return;
103
104         local_irq_save(flags);
105
106         out_le32(sdcasr_mapbase + SDCASR_REG + SDCASR_REG_STRIDE*cpu, astate);
107
108         local_irq_restore(flags);
109 }
110
111 int check_astate(void)
112 {
113         return get_cur_astate(hard_smp_processor_id());
114 }
115
116 void restore_astate(int cpu)
117 {
118         set_astate(cpu, current_astate);
119 }
120
121 /*
122  * cpufreq functions
123  */
124
125 static int pas_cpufreq_cpu_init(struct cpufreq_policy *policy)
126 {
127         struct cpufreq_frequency_table *pos;
128         const u32 *max_freqp;
129         u32 max_freq;
130         int cur_astate, idx;
131         struct resource res;
132         struct device_node *cpu, *dn;
133         int err = -ENODEV;
134
135         cpu = of_get_cpu_node(policy->cpu, NULL);
136         if (!cpu)
137                 goto out;
138
139         max_freqp = of_get_property(cpu, "clock-frequency", NULL);
140         of_node_put(cpu);
141         if (!max_freqp) {
142                 err = -EINVAL;
143                 goto out;
144         }
145
146         /* we need the freq in kHz */
147         max_freq = *max_freqp / 1000;
148
149         dn = of_find_compatible_node(NULL, NULL, "1682m-sdc");
150         if (!dn)
151                 dn = of_find_compatible_node(NULL, NULL,
152                                              "pasemi,pwrficient-sdc");
153         if (!dn)
154                 goto out;
155         err = of_address_to_resource(dn, 0, &res);
156         of_node_put(dn);
157         if (err)
158                 goto out;
159         sdcasr_mapbase = ioremap(res.start + SDCASR_OFFSET, 0x2000);
160         if (!sdcasr_mapbase) {
161                 err = -EINVAL;
162                 goto out;
163         }
164
165         dn = of_find_compatible_node(NULL, NULL, "1682m-gizmo");
166         if (!dn)
167                 dn = of_find_compatible_node(NULL, NULL,
168                                              "pasemi,pwrficient-gizmo");
169         if (!dn) {
170                 err = -ENODEV;
171                 goto out_unmap_sdcasr;
172         }
173         err = of_address_to_resource(dn, 0, &res);
174         of_node_put(dn);
175         if (err)
176                 goto out_unmap_sdcasr;
177         sdcpwr_mapbase = ioremap(res.start, 0x1000);
178         if (!sdcpwr_mapbase) {
179                 err = -EINVAL;
180                 goto out_unmap_sdcasr;
181         }
182
183         pr_debug("init cpufreq on CPU %d\n", policy->cpu);
184         pr_debug("max clock-frequency is at %u kHz\n", max_freq);
185         pr_debug("initializing frequency table\n");
186
187         /* initialize frequency table */
188         cpufreq_for_each_entry_idx(pos, pas_freqs, idx) {
189                 pos->frequency = get_astate_freq(pos->driver_data) * 100000;
190                 pr_debug("%d: %d\n", idx, pos->frequency);
191         }
192
193         cur_astate = get_cur_astate(policy->cpu);
194         pr_debug("current astate is at %d\n",cur_astate);
195
196         policy->cur = pas_freqs[cur_astate].frequency;
197         ppc_proc_freq = policy->cur * 1000ul;
198
199         cpufreq_generic_init(policy, pas_freqs, get_gizmo_latency());
200         return 0;
201
202 out_unmap_sdcasr:
203         iounmap(sdcasr_mapbase);
204 out:
205         return err;
206 }
207
208 static int pas_cpufreq_cpu_exit(struct cpufreq_policy *policy)
209 {
210         /*
211          * We don't support CPU hotplug. Don't unmap after the system
212          * has already made it to a running state.
213          */
214         if (system_state >= SYSTEM_RUNNING)
215                 return 0;
216
217         if (sdcasr_mapbase)
218                 iounmap(sdcasr_mapbase);
219         if (sdcpwr_mapbase)
220                 iounmap(sdcpwr_mapbase);
221
222         return 0;
223 }
224
225 static int pas_cpufreq_target(struct cpufreq_policy *policy,
226                               unsigned int pas_astate_new)
227 {
228         int i;
229
230         pr_debug("setting frequency for cpu %d to %d kHz, 1/%d of max frequency\n",
231                  policy->cpu,
232                  pas_freqs[pas_astate_new].frequency,
233                  pas_freqs[pas_astate_new].driver_data);
234
235         current_astate = pas_astate_new;
236
237         for_each_online_cpu(i)
238                 set_astate(i, pas_astate_new);
239
240         ppc_proc_freq = pas_freqs[pas_astate_new].frequency * 1000ul;
241         return 0;
242 }
243
244 static struct cpufreq_driver pas_cpufreq_driver = {
245         .name           = "pas-cpufreq",
246         .flags          = CPUFREQ_CONST_LOOPS,
247         .init           = pas_cpufreq_cpu_init,
248         .exit           = pas_cpufreq_cpu_exit,
249         .verify         = cpufreq_generic_frequency_table_verify,
250         .target_index   = pas_cpufreq_target,
251         .attr           = cpufreq_generic_attr,
252 };
253
254 /*
255  * module init and destoy
256  */
257
258 static int __init pas_cpufreq_init(void)
259 {
260         if (!of_machine_is_compatible("PA6T-1682M") &&
261             !of_machine_is_compatible("pasemi,pwrficient"))
262                 return -ENODEV;
263
264         return cpufreq_register_driver(&pas_cpufreq_driver);
265 }
266
267 static void __exit pas_cpufreq_exit(void)
268 {
269         cpufreq_unregister_driver(&pas_cpufreq_driver);
270 }
271
272 module_init(pas_cpufreq_init);
273 module_exit(pas_cpufreq_exit);
274
275 MODULE_LICENSE("GPL");
276 MODULE_AUTHOR("Egor Martovetsky <egor@pasemi.com>, Olof Johansson <olof@lixom.net>");