xref: /freebsd/sys/arm/qualcomm/qcom_cpu_kpssv2.c (revision af23369a6deaaeb612ab266eb88b8bb8d560c322)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2021 Adrian Chadd <adrian@FreeBSD.org>
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include "opt_platform.h"
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/bus.h>
36 #include <sys/reboot.h>
37 #include <sys/devmap.h>
38 #include <sys/smp.h>
39 
40 #include <vm/vm.h>
41 
42 #include <machine/cpu.h>
43 #include <machine/bus.h>
44 #include <machine/intr.h>
45 #include <machine/machdep.h>
46 #include <machine/platformvar.h>
47 #include <machine/smp.h>
48 
49 #include <dev/fdt/fdt_common.h>
50 #include <dev/ofw/openfirm.h>
51 #include <dev/ofw/ofw_cpu.h>
52 
53 #include <arm/qualcomm/qcom_cpu_kpssv2_reg.h>
54 #include <arm/qualcomm/qcom_cpu_kpssv2.h>
55 
56 #include "platform_if.h"
57 
58 /*
59  * Since DELAY() hangs this early, we need some way to
60  * delay things to settle.
61  */
62 static inline void
63 loop_delay(int usec)
64 {
65 	int lcount = usec * 100000;
66 
67 	for (volatile int i = 0; i < lcount; i++)
68 		;
69 }
70 
71 /*
72  * This is the KPSSv2 (eg IPQ4018) regulator path for CPU
73  * and shared L2 cache power-on.
74  */
75 boolean_t
76 qcom_cpu_kpssv2_regulator_start(u_int id, phandle_t node)
77 {
78 	phandle_t acc_phandle, l2_phandle, saw_phandle;
79 	bus_space_tag_t acc_tag, saw_tag;
80 	bus_space_handle_t acc_handle, saw_handle;
81 	bus_size_t acc_sz, saw_sz;
82 	ssize_t sret;
83 	int ret;
84 	uint32_t reg_val;
85 
86 	/*
87 	 * We don't need to power up CPU 0!  This will power it
88 	 * down first and ... then everything hangs.
89 	 */
90 	if (id == 0)
91 		return true;
92 
93 	/*
94 	 * Walk the qcom,acc and next-level-cache entries to find their
95 	 * child phandles and thus regulators.
96 	 *
97 	 * The qcom,acc is a phandle to a node.
98 	 *
99 	 * The next-level-cache actually is a phandle through to a qcom,saw
100 	 * entry.
101 	 */
102 	sret = OF_getencprop(node, "qcom,acc", (void *) &acc_phandle,
103 	    sizeof(acc_phandle));
104 	if (sret != sizeof(acc_phandle))
105 		panic("***couldn't get phandle for qcom,acc");
106 	acc_phandle = OF_node_from_xref(acc_phandle);
107 
108 	sret = OF_getencprop(node, "next-level-cache", (void *) &l2_phandle,
109 	    sizeof(l2_phandle));
110 	if (sret != sizeof(l2_phandle))
111 		panic("***couldn't get phandle for next-level-cache");
112 	l2_phandle = OF_node_from_xref(l2_phandle);
113 
114 	sret = OF_getencprop(l2_phandle, "qcom,saw", (void *) &saw_phandle,
115 	    sizeof(saw_phandle));
116 	if (sret != sizeof(saw_phandle))
117 		panic("***couldn't get phandle for qcom,saw");
118 	l2_phandle = OF_node_from_xref(l2_phandle);
119 
120 	/*
121 	 * Now that we have the phandles referencing the correct locations,
122 	 * do some KVA mappings so we can go access the registers.
123 	 */
124 	ret = OF_decode_addr(acc_phandle, 0, &acc_tag, &acc_handle, &acc_sz);
125 	if (ret != 0)
126 		panic("*** couldn't map qcom,acc space (%d)", ret);
127 	ret = OF_decode_addr(saw_phandle, 0, &saw_tag, &saw_handle, &saw_sz);
128 	if (ret != 0)
129 		panic("*** couldn't map next-level-cache -> "
130 		    "qcom,saw space (%d)", ret);
131 
132 	/*
133 	 * Power sequencing to ensure the cores are off, then power them on
134 	 * and bring them out of reset.
135 	 */
136 
137 	/*
138 	 * BHS: off
139 	 * LDO: bypassed, powered off
140 	 */
141 	reg_val = (64 << QCOM_APC_PWR_GATE_CTL_BHS_CNT_SHIFT)
142 	    | (0x3f << QCOM_APC_PWR_GATE_CTL_LDO_PWR_DWN_SHIFT)
143 	    | QCOM_APC_PWR_GATE_CTL_BHS_EN;
144 	bus_space_write_4(acc_tag, acc_handle, QCOM_APC_PWR_GATE_CTL, reg_val);
145 	mb();
146 	/* Settle time */
147 	loop_delay(1);
148 
149 	/*
150 	 * Start up BHS segments.
151 	 */
152 	reg_val |= 0x3f << QCOM_APC_PWR_GATE_CTL_BHS_SEG_SHIFT;
153 	bus_space_write_4(acc_tag, acc_handle, QCOM_APC_PWR_GATE_CTL, reg_val);
154 	mb();
155 	/* Settle time */
156 	loop_delay(1);
157 
158 	/*
159 	 * Switch on the LDO bypass; BHS will now supply power.
160 	 */
161 	reg_val |= 0x3f << QCOM_APC_PWR_GATE_CTL_LDO_BYP_SHIFT;
162 	bus_space_write_4(acc_tag, acc_handle, QCOM_APC_PWR_GATE_CTL, reg_val);
163 
164 	/*
165 	 * Shared L2 regulator control.
166 	 */
167 	bus_space_write_4(saw_tag, saw_handle, QCOM_APCS_SAW2_2_VCTL, 0x10003);
168 	mb();
169 	/* Settle time */
170 	loop_delay(50);
171 
172 	/*
173 	 * Put the core in reset.
174 	 */
175 	reg_val = QCOM_APCS_CPU_PWR_CTL_COREPOR_RST
176 	    | QCOM_APCS_CPU_PWR_CTL_CLAMP;
177 	bus_space_write_4(acc_tag, acc_handle, QCOM_APCS_CPU_PWR_CTL, reg_val);
178 	mb();
179 	loop_delay(2);
180 
181 	/*
182 	 * Remove power-down clamp.
183 	 */
184 	reg_val &= ~QCOM_APCS_CPU_PWR_CTL_CLAMP;
185 	bus_space_write_4(acc_tag, acc_handle, QCOM_APCS_CPU_PWR_CTL, reg_val);
186 	mb();
187 	loop_delay(2);
188 
189 	/*
190 	 * Clear core power reset.
191 	 */
192 	reg_val &= ~QCOM_APCS_CPU_PWR_CTL_COREPOR_RST;
193 	bus_space_write_4(acc_tag, acc_handle, QCOM_APCS_CPU_PWR_CTL, reg_val);
194 	mb();
195 
196 	/*
197 	 * The power is ready, the core is out of reset, signal the core
198 	 * to power up.
199 	 */
200 	reg_val |= QCOM_APCS_CPU_PWR_CTL_CORE_PWRD_UP;
201 	bus_space_write_4(acc_tag, acc_handle, QCOM_APCS_CPU_PWR_CTL, reg_val);
202 	mb();
203 
204 	/*
205 	 * Finished with these KVA mappings, so release them.
206 	 */
207 	bus_space_unmap(acc_tag, acc_handle, acc_sz);
208 	bus_space_unmap(saw_tag, saw_handle, saw_sz);
209 
210 	return true;
211 }
212