xref: /netbsd-src/sys/arch/evbmips/ingenic/clock.c (revision 5dd36a3bc8bf2a9dec29ceb6349550414570c447)
1 /*	$NetBSD: clock.c,v 1.10 2017/05/21 06:49:12 skrll Exp $ */
2 
3 /*-
4  * Copyright (c) 2014 Michael Lorenz
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26  * POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __KERNEL_RCSID(0, "$NetBSD: clock.c,v 1.10 2017/05/21 06:49:12 skrll Exp $");
31 
32 #include "opt_multiprocessor.h"
33 
34 #include <sys/param.h>
35 #include <sys/cpu.h>
36 #include <sys/device.h>
37 #include <sys/kernel.h>
38 #include <sys/systm.h>
39 #include <sys/timetc.h>
40 
41 #include <mips/ingenic/ingenic_var.h>
42 #include <mips/ingenic/ingenic_regs.h>
43 
44 #include "opt_ingenic.h"
45 
46 extern void ingenic_puts(const char *);
47 
48 void ingenic_clockintr(struct clockframe *);
49 
50 static u_int
51 ingenic_count_read(struct timecounter *tc)
52 {
53 	return readreg(JZ_OST_CNT_LO);
54 }
55 
56 void
57 cpu_initclocks(void)
58 {
59 	struct cpu_info * const ci = curcpu();
60 	uint32_t cnt;
61 
62 	static struct timecounter tc =  {
63 		ingenic_count_read,		/* get_timecount */
64 		0,				/* no poll_pps */
65 		~0u,				/* counter_mask */
66 		12000000,			/* frequency */
67 		"Ingenic OS timer",		/* name */
68 		100,				/* quality */
69 	};
70 
71 	curcpu()->ci_cctr_freq = tc.tc_frequency;
72 
73 	tc_init(&tc);
74 
75 	printf("starting timer interrupt...\n");
76 	/* start the timer interrupt */
77 	cnt = readreg(JZ_OST_CNT_LO);
78 	ci->ci_next_cp0_clk_intr = cnt + ci->ci_cycles_per_hz;
79 	writereg(JZ_TC_TFCR, TFR_OSTFLAG);
80 	writereg(JZ_OST_DATA, ci->ci_next_cp0_clk_intr);
81 	/*
82 	 * XXX
83 	 * We can use OST or one of the regular timers to generate the 100hz
84 	 * interrupt. OST interrupts need to be rescheduled every time and by
85 	 * only one core, the regular timer can be programmed to fire every
86 	 * 10ms without rescheduling and we'd still use the OST as time base.
87 	 * OST is supposed to fire on INT2 although I haven't been able to get
88 	 * that to work yet ( all I get is INT0 which is for hardware interrupts
89 	 * in general )
90 	 * So if we can get OST to fire on INT2 we can just block INT0 on core1
91 	 * and have a timer interrupt on both cores, if not the regular timer
92 	 * would be more convenient but we'd have to shoot an IPI to core1 on
93 	 * every tick.
94 	 * For now, use OST and hope we'll figure out how to make it fire on
95 	 * INT2.
96 	 */
97 #ifdef USE_OST
98 	writereg(JZ_TC_TMCR, TFR_OSTFLAG);
99 #else
100 	writereg(JZ_TC_TECR, TESR_TCST5);	/* disable timer 5 */
101 	writereg(JZ_TC_TCNT(5), 0);
102 	writereg(JZ_TC_TDFR(5), 30000);	/* 10ms at 48MHz / 16 */
103 	writereg(JZ_TC_TDHR(5), 60000);	/* not reached */
104 	writereg(JZ_TC_TCSR(5), TCSR_EXT_EN| TCSR_DIV_16);
105 	writereg(JZ_TC_TMCR, TFR_FFLAG5);
106 	writereg(JZ_TC_TFCR, TFR_FFLAG5);
107 	writereg(JZ_TC_TESR, TESR_TCST5);	/* enable timer 5 */
108 #endif
109 
110 #ifdef INGENIC_CLOCK_DEBUG
111 	printf("INTC %08x %08x\n", readreg(JZ_ICSR0), readreg(JZ_ICSR1));
112 	printf("ICMR0 %08x\n", readreg(JZ_ICMR0));
113 #endif
114 	writereg(JZ_ICMCR0, 0x0c000000); /* TCU2, OST */
115 	spl0();
116 #ifdef INGENIC_CLOCK_DEBUG
117 	printf("TFR: %08x\n", readreg(JZ_TC_TFR));
118 	printf("TMR: %08x\n", readreg(JZ_TC_TMR));
119 	printf("cnt5: %08x\n", readreg(JZ_TC_TCNT(5)));
120 	printf("CR: %08x\n", MFC0(MIPS_COP_0_CAUSE, 0));
121 	printf("SR: %08x\n", MFC0(MIPS_COP_0_STATUS, 0));
122 	delay(100000);
123 	printf("TFR: %08x\n", readreg(JZ_TC_TFR));
124 	printf("TMR: %08x\n", readreg(JZ_TC_TMR));
125 	printf("cnt5: %08x\n", readreg(JZ_TC_TCNT(5)));
126 	printf("CR: %08x\n", MFC0(MIPS_COP_0_CAUSE, 0));
127 	printf("SR: %08x\n", MFC0(MIPS_COP_0_STATUS, 0));
128 	printf("TFR: %08x\n", readreg(JZ_TC_TFR));
129 	printf("TMR: %08x\n", readreg(JZ_TC_TMR));
130 	printf("cnt5: %08x\n", readreg(JZ_TC_TCNT(5)));
131 	printf("CR: %08x\n", MFC0(MIPS_COP_0_CAUSE, 0));
132 	printf("SR: %08x\n", MFC0(MIPS_COP_0_STATUS, 0));
133 
134 	printf("INTC %08x %08x\n", readreg(JZ_ICSR0), readreg(JZ_ICSR1));
135 	delay(3000000);
136 	printf("%s %d\n", __func__, MFC0(12, 3));
137 	printf("%s %08x\n", __func__, MFC0(12, 4));
138 #endif
139 }
140 
141 /* shamelessly stolen from mips3_clock.c */
142 void
143 delay(int n)
144 {
145 	u_long divisor_delay;
146 	uint32_t cur, last, delta, usecs;
147 
148 	last = readreg(JZ_OST_CNT_LO);
149 	delta = usecs = 0;
150 
151 	divisor_delay = curcpu()->ci_divisor_delay;
152 	if (divisor_delay == 0) {
153 		/*
154 		 * Frequency values in curcpu() are not initialized.
155 		 * Assume faster frequency since longer delays are harmless.
156 		 * Note CPU_MIPS_DOUBLE_COUNT is ignored here.
157 		 */
158 #define FAST_FREQ	(300 * 1000 * 1000)	/* fast enough? */
159 		divisor_delay = FAST_FREQ / (1000 * 1000);
160 	}
161 	while (n > usecs) {
162 		cur = readreg(JZ_OST_CNT_LO);
163 
164 		/*
165 		 * We setup the OS timer to always counts upto UINT32_MAX,
166 		 * so no need to check wrapped around case.
167 		 */
168 		delta += (cur - last);
169 
170 		last = cur;
171 
172 		while (delta >= divisor_delay) {
173 			/*
174 			 * delta is not so larger than divisor_delay here,
175 			 * and using DIV/DIVU ops could be much slower.
176 			 * (though longer delay may be harmless)
177 			 */
178 			usecs++;
179 			delta -= divisor_delay;
180 		}
181 	}
182 }
183 
184 void
185 setstatclockrate(int r)
186 {
187 	/* we could just use another timer channel here */
188 }
189 
190 #ifdef INGENIC_CLOCK_DEBUG
191 int cnt = 99;
192 #endif
193 
194 void
195 ingenic_clockintr(struct clockframe *cf)
196 {
197 	int s = splsched();
198 	struct cpu_info * const ci = curcpu();
199 #ifdef USE_OST
200 	uint32_t new_cnt;
201 #endif
202 
203 	/* clear flags */
204 	writereg(JZ_TC_TFCR, TFR_OSTFLAG);
205 
206 	ci->ci_next_cp0_clk_intr += (uint32_t)(ci->ci_cycles_per_hz & 0xffffffff);
207 #ifdef USE_OST
208 	writereg(JZ_OST_DATA, ci->ci_next_cp0_clk_intr);
209 
210 	/* Check for lost clock interrupts */
211 	new_cnt = readreg(JZ_OST_CNT_LO);
212 
213 	/*
214 	 * Missed one or more clock interrupts, so let's start
215 	 * counting again from the current value.
216 	 */
217 	if ((ci->ci_next_cp0_clk_intr - new_cnt) & 0x80000000) {
218 
219 		ci->ci_next_cp0_clk_intr = new_cnt + curcpu()->ci_cycles_per_hz;
220 		writereg(JZ_OST_DATA, ci->ci_next_cp0_clk_intr);
221 		curcpu()->ci_ev_count_compare_missed.ev_count++;
222 	}
223 	writereg(JZ_TC_TFCR, TFR_OSTFLAG);
224 #else
225 	writereg(JZ_TC_TFCR, TFR_FFLAG5);
226 #endif
227 
228 #ifdef INGENIC_CLOCK_DEBUG
229 	cnt++;
230 	if (cnt == 100) {
231 		cnt = 0;
232 		ingenic_puts("+");
233 	}
234 #endif
235 #ifdef MULTIPROCESSOR
236 	/*
237 	 * XXX
238 	 * needs to take the IPI lock and ping all online CPUs, not just core 1
239 	 */
240 	mips_cp0_corembox_write(1, 1 << IPI_CLOCK);
241 #endif
242 	hardclock(cf);
243 	splx(s);
244 }
245