Re: [Qemu-devel] [PATCH RFC v8 07/12] hw/timer: RX62N internal timer modules

[Yoshinori Sato <ysato@users.sourceforge.jp>]

On Sat, 04 May 2019 00:20:47 +0900,
Alex Bennée wrote:
> 
> 
> Yoshinori Sato <ysato@users.sourceforge.jp> writes:
> 
> > renesas_tmr: 8bit timer modules.
> > renesas_cmt: 16bit compare match timer modules.
> > This part use many renesas's CPU.
> > Hardware manual.
> > https://www.renesas.com/us/en/doc/products/mpumcu/doc/rx_family/r01uh0033ej0140_rx62n.pdf
> >
> > Signed-off-by: Yoshinori Sato <ysato@users.sourceforge.jp>
> > ---
> >  include/hw/timer/renesas_cmt.h |  33 +++
> >  include/hw/timer/renesas_tmr.h |  46 +++++
> >  hw/timer/renesas_cmt.c         | 277 +++++++++++++++++++++++++
> >  hw/timer/renesas_tmr.c         | 458 +++++++++++++++++++++++++++++++++++++++++
> >  hw/timer/Kconfig               |   6 +
> >  hw/timer/Makefile.objs         |   3 +
> >  6 files changed, 823 insertions(+)
> >  create mode 100644 include/hw/timer/renesas_cmt.h
> >  create mode 100644 include/hw/timer/renesas_tmr.h
> >  create mode 100644 hw/timer/renesas_cmt.c
> >  create mode 100644 hw/timer/renesas_tmr.c
> >
> > diff --git a/include/hw/timer/renesas_cmt.h b/include/hw/timer/renesas_cmt.h
> > new file mode 100644
> > index 0000000000..7e393d7ad3
> > --- /dev/null
> > +++ b/include/hw/timer/renesas_cmt.h
> > @@ -0,0 +1,33 @@
> > +/*
> > + * Renesas Compare-match timer Object
> > + *
> > + * Copyright (c) 2019 Yoshinori Sato
> > + *
> > + * This code is licensed under the GPL version 2 or later.
> > + *
> > + */
> > +
> > +#ifndef HW_RENESAS_CMT_H
> > +#define HW_RENESAS_CMT_H
> > +
> > +#include "hw/sysbus.h"
> > +
> > +#define TYPE_RENESAS_CMT "renesas-cmt"
> > +#define RCMT(obj) OBJECT_CHECK(RCMTState, (obj), TYPE_RENESAS_CMT)
> > +
> > +typedef struct RCMTState {
> > +    SysBusDevice parent_obj;
> > +
> > +    uint64_t input_freq;
> > +    MemoryRegion memory;
> > +
> > +    uint16_t cmstr;
> > +    uint16_t cmcr[2];
> > +    uint16_t cmcnt[2];
> > +    uint16_t cmcor[2];
> > +    int64_t tick[2];
> > +    qemu_irq cmi[2];
> > +    QEMUTimer *timer[2];
> > +} RCMTState;
> > +
> > +#endif
> > diff --git a/include/hw/timer/renesas_tmr.h b/include/hw/timer/renesas_tmr.h
> > new file mode 100644
> > index 0000000000..718d9dc4ff
> > --- /dev/null
> > +++ b/include/hw/timer/renesas_tmr.h
> > @@ -0,0 +1,46 @@
> > +/*
> > + * Renesas 8bit timer Object
> > + *
> > + * Copyright (c) 2018 Yoshinori Sato
> > + *
> > + * This code is licensed under the GPL version 2 or later.
> > + *
> > + */
> > +
> > +#ifndef HW_RENESAS_TMR_H
> > +#define HW_RENESAS_TMR_H
> > +
> > +#include "hw/sysbus.h"
> > +
> > +#define TYPE_RENESAS_TMR "renesas-tmr"
> > +#define RTMR(obj) OBJECT_CHECK(RTMRState, (obj), TYPE_RENESAS_TMR)
> > +
> > +enum timer_event {cmia = 0,
> > +                  cmib = 1,
> > +                  ovi = 2,
> > +                  none = 3,
> > +                  TMR_NR_EVENTS = 4};
> > +enum {CH = 2};
> > +typedef struct RTMRState {
> > +    SysBusDevice parent_obj;
> > +
> > +    uint64_t input_freq;
> > +    MemoryRegion memory;
> > +
> > +    uint8_t tcnt[CH];
> > +    uint8_t tcora[CH];
> > +    uint8_t tcorb[CH];
> > +    uint8_t tcr[CH];
> > +    uint8_t tccr[CH];
> > +    uint8_t tcor[CH];
> > +    uint8_t tcsr[CH];
> > +    int64_t tick;
> > +    int64_t div_round[CH];
> > +    enum timer_event next[CH];
> > +    qemu_irq cmia[CH];
> > +    qemu_irq cmib[CH];
> > +    qemu_irq ovi[CH];
> > +    QEMUTimer *timer[CH];
> > +} RTMRState;
> > +
> > +#endif
> > diff --git a/hw/timer/renesas_cmt.c b/hw/timer/renesas_cmt.c
> > new file mode 100644
> > index 0000000000..b82250dbc2
> > --- /dev/null
> > +++ b/hw/timer/renesas_cmt.c
> > @@ -0,0 +1,277 @@
> > +/*
> > + * Renesas 16bit Compare-match timer
> > + *
> > + * Datasheet: RX62N Group, RX621 Group User's Manual: Hardware
> > + * (Rev.1.40 R01UH0033EJ0140)
> > + *
> > + * Copyright (c) 2019 Yoshinori Sato
> > + *
> > + * This program is free software; you can redistribute it and/or modify it
> > + * under the terms and conditions of the GNU General Public License,
> > + * version 2 or later, as published by the Free Software Foundation.
> > + *
> > + * This program is distributed in the hope it will be useful, but WITHOUT
> > + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> > + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
> > + * more details.
> > + *
> > + * You should have received a copy of the GNU General Public License along with
> > + * this program.  If not, see <http://www.gnu.org/licenses/>.
> > + */
> > +
> > +#include "qemu/osdep.h"
> > +#include "qemu-common.h"
> > +#include "qemu/log.h"
> > +#include "qapi/error.h"
> > +#include "qemu/timer.h"
> > +#include "cpu.h"
> > +#include "hw/hw.h"
> > +#include "hw/sysbus.h"
> > +#include "hw/registerfields.h"
> > +#include "hw/timer/renesas_cmt.h"
> > +#include "qemu/error-report.h"
> > +
> > +/*
> > + *  +0 CMSTR - common control
> > + *  +2 CMCR  - ch0
> > + *  +4 CMCNT - ch0
> > + *  +6 CMCOR - ch0
> > + *  +8 CMCR  - ch1
> > + * +10 CMCNT - ch1
> > + * +12 CMCOR - ch1
> > + * If we think that the address of CH 0 has an offset of +2,
> > + * we can treat it with the same address as CH 1, so define it like that.
> > + */
> > +REG16(CMSTR, 0)
> > +  FIELD(CMSTR, STR0, 0, 1)
> > +  FIELD(CMSTR, STR1, 1, 1)
> > +  FIELD(CMSTR, STR,  0, 2)
> > +/* This addeess is channel offset */
> > +REG16(CMCR, 0)
> > +  FIELD(CMCR, CKS, 0, 2)
> > +  FIELD(CMCR, CMIE, 6, 1)
> > +REG16(CMCNT, 2)
> > +REG16(CMCOR, 4)
> > +
> > +static void update_events(RCMTState *cmt, int ch)
> > +{
> > +    int64_t next_time;
> > +
> > +    if ((cmt->cmstr & (1 << ch)) == 0) {
> > +        /* count disable, so not happened next event. */
> > +        return ;
> > +    }
> > +    next_time = cmt->cmcor[ch] - cmt->cmcnt[ch];
> > +    next_time *= NANOSECONDS_PER_SECOND;
> > +    next_time /= cmt->input_freq;
> > +    /*
> > +     * CKS -> div rate
> > +     *  0 -> 8 (1 << 3)
> > +     *  1 -> 32 (1 << 5)
> > +     *  2 -> 128 (1 << 7)
> > +     *  3 -> 512 (1 << 9)
> > +     */
> > +    next_time *= 1 << (3 + FIELD_EX16(cmt->cmcr[ch], CMCR, CKS) * 2);
> > +    next_time += qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
> > +    timer_mod(cmt->timer[ch], next_time);
> > +}
> > +
> > +static int64_t read_cmcnt(RCMTState *cmt, int ch)
> > +{
> > +    int64_t delta, now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
> > +
> > +    if (cmt->cmstr & (1 << ch)) {
> > +        delta = (now - cmt->tick[ch]);
> > +        delta /= NANOSECONDS_PER_SECOND;
> > +        delta /= cmt->input_freq;
> > +        delta /= 1 << (3 + FIELD_EX16(cmt->cmcr[ch], CMCR, CKS) * 2);
> > +        cmt->tick[ch] = now;
> > +        return cmt->cmcnt[ch] + delta;
> > +    } else {
> > +        return cmt->cmcnt[ch];
> > +    }
> > +}
> > +
> > +static uint64_t cmt_read(void *opaque, hwaddr addr, unsigned size)
> > +{
> > +    hwaddr offset = addr & 0x0f;
> > +    RCMTState *cmt = opaque;
> > +    int ch = offset / 0x08;
> > +    uint64_t ret;
> > +
> > +    if (offset == A_CMSTR) {
> > +        ret = 0;
> > +        ret = FIELD_DP16(ret, CMSTR, STR,
> > +                         FIELD_EX16(cmt->cmstr, CMSTR, STR));
> > +        return ret;
> > +    } else {
> > +        offset &= 0x07;
> > +        if (ch == 0) {
> > +            offset -= 0x02;
> > +        }
> > +        switch (offset) {
> > +        case A_CMCR:
> > +            ret = 0;
> > +            ret = FIELD_DP16(ret, CMCR, CKS,
> > +                             FIELD_EX16(cmt->cmstr, CMCR, CKS));
> > +            ret = FIELD_DP16(ret, CMCR, CMIE,
> > +                             FIELD_EX16(cmt->cmstr, CMCR, CMIE));
> > +            return ret;
> > +        case A_CMCNT:
> > +            return read_cmcnt(cmt, ch);
> > +        case A_CMCOR:
> > +            return cmt->cmcor[ch];
> > +        }
> > +    }
> > +    qemu_log_mask(LOG_UNIMP,
> > +                  "renesas_cmt: Register %08lx not implemented\n",
> > +                  offset);
> > +    return 0xffffffffffffffffUL;
> > +}
> > +
> > +static void start_stop(RCMTState *cmt, int ch, int st)
> > +{
> > +    if (st) {
> > +        update_events(cmt, ch);
> > +    } else {
> > +        timer_del(cmt->timer[ch]);
> > +    }
> > +}
> > +
> > +static void cmt_write(void *opaque, hwaddr addr, uint64_t val, unsigned size)
> > +{
> > +    hwaddr offset = addr & 0x0f;
> > +    RCMTState *cmt = opaque;
> > +    int ch = offset / 0x08;
> > +
> > +    if (offset == A_CMSTR) {
> > +        cmt->cmstr = FIELD_EX16(val, CMSTR, STR);
> > +        start_stop(cmt, 0, FIELD_EX16(cmt->cmstr, CMSTR, STR0));
> > +        start_stop(cmt, 1, FIELD_EX16(cmt->cmstr, CMSTR, STR1));
> > +    } else {
> > +        offset &= 0x07;
> > +        if (ch == 0) {
> > +            offset -= 0x02;
> > +        }
> > +        switch (offset) {
> > +        case A_CMCR:
> > +            cmt->cmcr[ch] = FIELD_DP16(cmt->cmcr[ch], CMCR, CKS,
> > +                                       FIELD_EX16(val, CMCR, CKS));
> > +            cmt->cmcr[ch] = FIELD_DP16(cmt->cmcr[ch], CMCR, CMIE,
> > +                                       FIELD_EX16(val, CMCR, CMIE));
> > +            break;
> > +        case 2:
> > +            cmt->cmcnt[ch] = val;
> > +            break;
> > +        case 4:
> > +            cmt->cmcor[ch] = val;
> > +            break;
> > +        default:
> > +            qemu_log_mask(LOG_UNIMP,
> > +                          "renesas_cmt: Register %08lx not implemented\n",
> > +                          offset);
> > +            return;
> > +        }
> > +        if (FIELD_EX16(cmt->cmstr, CMSTR, STR) & (1 << ch)) {
> > +            update_events(cmt, ch);
> > +        }
> > +    }
> > +}
> > +
> > +static const MemoryRegionOps cmt_ops = {
> > +    .write = cmt_write,
> > +    .read  = cmt_read,
> > +    .endianness = DEVICE_NATIVE_ENDIAN,
> > +    .impl = {
> > +        .min_access_size = 2,
> > +        .max_access_size = 2,
> > +    },
> > +};
> > +
> > +static void timer_events(RCMTState *cmt, int ch)
> > +{
> > +    cmt->cmcnt[ch] = 0;
> > +    cmt->tick[ch] = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
> > +    update_events(cmt, ch);
> > +    if (FIELD_EX16(cmt->cmcr[ch], CMCR, CMIE)) {
> > +        qemu_irq_pulse(cmt->cmi[ch]);
> > +    }
> > +}
> > +
> > +static void timer_event0(void *opaque)
> > +{
> > +    RCMTState *cmt = opaque;
> > +
> > +    timer_events(cmt, 0);
> > +}
> > +
> > +static void timer_event1(void *opaque)
> > +{
> > +    RCMTState *cmt = opaque;
> > +
> > +    timer_events(cmt, 1);
> > +}
> 
> I guess there is enough shared state RCMTState that you couldn't have an
> array of channel structures and just pass that when you setup the
> timers:
> 
> > +static void rcmt_init(Object *obj)
> > +{
> <snip>
> > +    cmt->timer[0] = timer_new_ns(QEMU_CLOCK_VIRTUAL, timer_event0, cmt);
> > +    cmt->timer[1] = timer_new_ns(QEMU_CLOCK_VIRTUAL, timer_event1,
> > cmt);
> 
> here?

Yes.
The shared part is only access from the CPU,
so I don't think there will be a conflict in the timer's event.
If problems occur, fix it to manage with one timer.

> Anyway:
> 
> Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
> 
> --
> Alex Bennée
> 

-- 
Yosinori Sato