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
39static void __iomem *sdcpwr_mapbase;
40static 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 */
46static int current_astate;
47
48/* We support 5(A0-A4) power states excluding turbo(A5-A6) modes */
49static 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
62static 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
70static 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
80static 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
95static 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
110int check_astate(void)
111{
112	return get_cur_astate(hard_smp_processor_id());
113}
114
115void restore_astate(int cpu)
116{
117	set_astate(cpu, current_astate);
118}
119
120/*
121 * cpufreq functions
122 */
123
124static 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(policy->cpu, NULL);
135	if (!cpu)
136		goto out;
137
138	max_freqp = of_get_property(cpu, "clock-frequency", NULL);
139	of_node_put(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, "1682m-sdc");
149	if (!dn)
150		dn = of_find_compatible_node(NULL, NULL,
151					     "pasemi,pwrficient-sdc");
152	if (!dn)
153		goto out;
154	err = of_address_to_resource(dn, 0, &res);
155	of_node_put(dn);
156	if (err)
157		goto out;
158	sdcasr_mapbase = ioremap(res.start + SDCASR_OFFSET, 0x2000);
159	if (!sdcasr_mapbase) {
160		err = -EINVAL;
161		goto out;
162	}
163
164	dn = of_find_compatible_node(NULL, NULL, "1682m-gizmo");
165	if (!dn)
166		dn = of_find_compatible_node(NULL, NULL,
167					     "pasemi,pwrficient-gizmo");
168	if (!dn) {
169		err = -ENODEV;
170		goto out_unmap_sdcasr;
171	}
172	err = of_address_to_resource(dn, 0, &res);
173	of_node_put(dn);
174	if (err)
175		goto out_unmap_sdcasr;
176	sdcpwr_mapbase = ioremap(res.start, 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(pos->driver_data) * 100000;
189		pr_debug("%d: %d\n", idx, pos->frequency);
190	}
191
192	cur_astate = get_cur_astate(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, pas_freqs, get_gizmo_latency());
199	return 0;
200
201out_unmap_sdcasr:
202	iounmap(sdcasr_mapbase);
203out:
204	return err;
205}
206
207static 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(sdcasr_mapbase);
218	if (sdcpwr_mapbase)
219		iounmap(sdcpwr_mapbase);
220
221	return 0;
222}
223
224static 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(i, pas_astate_new);
238
239	ppc_proc_freq = pas_freqs[pas_astate_new].frequency * 1000ul;
240	return 0;
241}
242
243static 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
257static int __init pas_cpufreq_init(void)
258{
259	if (!of_machine_is_compatible("PA6T-1682M") &&
260	    !of_machine_is_compatible("pasemi,pwrficient"))
261		return -ENODEV;
262
263	return cpufreq_register_driver(&pas_cpufreq_driver);
264}
265
266static void __exit pas_cpufreq_exit(void)
267{
268	cpufreq_unregister_driver(&pas_cpufreq_driver);
269}
270
271module_init(pas_cpufreq_init);
272module_exit(pas_cpufreq_exit);
273
274MODULE_LICENSE("GPL");
275MODULE_AUTHOR("Egor Martovetsky <egor@pasemi.com>, Olof Johansson <olof@lixom.net>");
276