xref: /freebsd/sys/arm/qualcomm/qcom_cpu_kpssv2.c (revision 06c3fb2749bda94cb5201f81ffdb8fa6c3161b2e)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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/param.h>
31 #include <sys/systm.h>
32 #include <sys/bus.h>
33 #include <sys/reboot.h>
34 #include <sys/devmap.h>
35 #include <sys/smp.h>
36 
37 #include <vm/vm.h>
38 
39 #include <machine/cpu.h>
40 #include <machine/bus.h>
41 #include <machine/intr.h>
42 #include <machine/machdep.h>
43 #include <machine/platformvar.h>
44 #include <machine/smp.h>
45 
46 #include <dev/fdt/fdt_common.h>
47 #include <dev/ofw/openfirm.h>
48 #include <dev/ofw/ofw_cpu.h>
49 
50 #include <arm/qualcomm/qcom_cpu_kpssv2_reg.h>
51 #include <arm/qualcomm/qcom_cpu_kpssv2.h>
52 
53 #include "platform_if.h"
54 
55 /*
56  * Since DELAY() hangs this early, we need some way to
57  * delay things to settle.
58  */
59 static inline void
60 loop_delay(int usec)
61 {
62 	int lcount = usec * 100000;
63 
64 	for (volatile int i = 0; i < lcount; i++)
65 		;
66 }
67 
68 /*
69  * This is the KPSSv2 (eg IPQ4018) regulator path for CPU
70  * and shared L2 cache power-on.
71  */
72 bool
73 qcom_cpu_kpssv2_regulator_start(u_int id, phandle_t node)
74 {
75 	phandle_t acc_phandle, l2_phandle, saw_phandle;
76 	bus_space_tag_t acc_tag, saw_tag;
77 	bus_space_handle_t acc_handle, saw_handle;
78 	bus_size_t acc_sz, saw_sz;
79 	ssize_t sret;
80 	int ret;
81 	uint32_t reg_val;
82 
83 	/*
84 	 * We don't need to power up CPU 0!  This will power it
85 	 * down first and ... then everything hangs.
86 	 */
87 	if (id == 0)
88 		return true;
89 
90 	/*
91 	 * Walk the qcom,acc and next-level-cache entries to find their
92 	 * child phandles and thus regulators.
93 	 *
94 	 * The qcom,acc is a phandle to a node.
95 	 *
96 	 * The next-level-cache actually is a phandle through to a qcom,saw
97 	 * entry.
98 	 */
99 	sret = OF_getencprop(node, "qcom,acc", (void *) &acc_phandle,
100 	    sizeof(acc_phandle));
101 	if (sret != sizeof(acc_phandle))
102 		panic("***couldn't get phandle for qcom,acc");
103 	acc_phandle = OF_node_from_xref(acc_phandle);
104 
105 	sret = OF_getencprop(node, "next-level-cache", (void *) &l2_phandle,
106 	    sizeof(l2_phandle));
107 	if (sret != sizeof(l2_phandle))
108 		panic("***couldn't get phandle for next-level-cache");
109 	l2_phandle = OF_node_from_xref(l2_phandle);
110 
111 	sret = OF_getencprop(l2_phandle, "qcom,saw", (void *) &saw_phandle,
112 	    sizeof(saw_phandle));
113 	if (sret != sizeof(saw_phandle))
114 		panic("***couldn't get phandle for qcom,saw");
115 	l2_phandle = OF_node_from_xref(l2_phandle);
116 
117 	/*
118 	 * Now that we have the phandles referencing the correct locations,
119 	 * do some KVA mappings so we can go access the registers.
120 	 */
121 	ret = OF_decode_addr(acc_phandle, 0, &acc_tag, &acc_handle, &acc_sz);
122 	if (ret != 0)
123 		panic("*** couldn't map qcom,acc space (%d)", ret);
124 	ret = OF_decode_addr(saw_phandle, 0, &saw_tag, &saw_handle, &saw_sz);
125 	if (ret != 0)
126 		panic("*** couldn't map next-level-cache -> "
127 		    "qcom,saw space (%d)", ret);
128 
129 	/*
130 	 * Power sequencing to ensure the cores are off, then power them on
131 	 * and bring them out of reset.
132 	 */
133 
134 	/*
135 	 * BHS: off
136 	 * LDO: bypassed, powered off
137 	 */
138 	reg_val = (64 << QCOM_APC_PWR_GATE_CTL_BHS_CNT_SHIFT)
139 	    | (0x3f << QCOM_APC_PWR_GATE_CTL_LDO_PWR_DWN_SHIFT)
140 	    | QCOM_APC_PWR_GATE_CTL_BHS_EN;
141 	bus_space_write_4(acc_tag, acc_handle, QCOM_APC_PWR_GATE_CTL, reg_val);
142 	mb();
143 	/* Settle time */
144 	loop_delay(1);
145 
146 	/*
147 	 * Start up BHS segments.
148 	 */
149 	reg_val |= 0x3f << QCOM_APC_PWR_GATE_CTL_BHS_SEG_SHIFT;
150 	bus_space_write_4(acc_tag, acc_handle, QCOM_APC_PWR_GATE_CTL, reg_val);
151 	mb();
152 	/* Settle time */
153 	loop_delay(1);
154 
155 	/*
156 	 * Switch on the LDO bypass; BHS will now supply power.
157 	 */
158 	reg_val |= 0x3f << QCOM_APC_PWR_GATE_CTL_LDO_BYP_SHIFT;
159 	bus_space_write_4(acc_tag, acc_handle, QCOM_APC_PWR_GATE_CTL, reg_val);
160 
161 	/*
162 	 * Shared L2 regulator control.
163 	 */
164 	bus_space_write_4(saw_tag, saw_handle, QCOM_APCS_SAW2_2_VCTL, 0x10003);
165 	mb();
166 	/* Settle time */
167 	loop_delay(50);
168 
169 	/*
170 	 * Put the core in reset.
171 	 */
172 	reg_val = QCOM_APCS_CPU_PWR_CTL_COREPOR_RST
173 	    | QCOM_APCS_CPU_PWR_CTL_CLAMP;
174 	bus_space_write_4(acc_tag, acc_handle, QCOM_APCS_CPU_PWR_CTL, reg_val);
175 	mb();
176 	loop_delay(2);
177 
178 	/*
179 	 * Remove power-down clamp.
180 	 */
181 	reg_val &= ~QCOM_APCS_CPU_PWR_CTL_CLAMP;
182 	bus_space_write_4(acc_tag, acc_handle, QCOM_APCS_CPU_PWR_CTL, reg_val);
183 	mb();
184 	loop_delay(2);
185 
186 	/*
187 	 * Clear core power reset.
188 	 */
189 	reg_val &= ~QCOM_APCS_CPU_PWR_CTL_COREPOR_RST;
190 	bus_space_write_4(acc_tag, acc_handle, QCOM_APCS_CPU_PWR_CTL, reg_val);
191 	mb();
192 
193 	/*
194 	 * The power is ready, the core is out of reset, signal the core
195 	 * to power up.
196 	 */
197 	reg_val |= QCOM_APCS_CPU_PWR_CTL_CORE_PWRD_UP;
198 	bus_space_write_4(acc_tag, acc_handle, QCOM_APCS_CPU_PWR_CTL, reg_val);
199 	mb();
200 
201 	/*
202 	 * Finished with these KVA mappings, so release them.
203 	 */
204 	bus_space_unmap(acc_tag, acc_handle, acc_sz);
205 	bus_space_unmap(saw_tag, saw_handle, saw_sz);
206 
207 	return true;
208 }
209