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Re: [PATCH v8 02/14] hw/misc: Add NPCM7xx Clock Controller device model
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From: |
Havard Skinnemoen |
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Subject: |
Re: [PATCH v8 02/14] hw/misc: Add NPCM7xx Clock Controller device model |
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Date: |
Fri, 4 Sep 2020 15:38:38 -0700 |
On Fri, Sep 4, 2020 at 3:02 PM Havard Skinnemoen <hskinnemoen@google.com> wrote:
>
> On Fri, Sep 4, 2020 at 2:32 AM Philippe Mathieu-Daudé <f4bug@amsat.org> wrote:
> >
> > On 8/25/20 2:16 AM, Havard Skinnemoen via wrote:
> > > Enough functionality to boot the Linux kernel has been implemented. This
> > > includes:
> > >
> > > - Correct power-on reset values so the various clock rates can be
> > > accurately calculated.
> > > - Clock enables stick around when written.
> > >
> > > In addition, a best effort attempt to implement SECCNT and CNTR25M was
> > > made even though I don't think the kernel needs them.
> > >
> > > Reviewed-by: Tyrone Ting <kfting@nuvoton.com>
> > > Reviewed-by: Joel Stanley <joel@jms.id.au>
> > > Reviewed-by: Cédric Le Goater <clg@kaod.org>
> > > Signed-off-by: Havard Skinnemoen <hskinnemoen@google.com>
> > > ---
> > > include/hw/misc/npcm7xx_clk.h | 48 ++++++
> > > hw/misc/npcm7xx_clk.c | 266 ++++++++++++++++++++++++++++++++++
> > > hw/misc/meson.build | 1 +
> > > hw/misc/trace-events | 4 +
> > > 4 files changed, 319 insertions(+)
> > > create mode 100644 include/hw/misc/npcm7xx_clk.h
> > > create mode 100644 hw/misc/npcm7xx_clk.c
> > >
> > > diff --git a/include/hw/misc/npcm7xx_clk.h b/include/hw/misc/npcm7xx_clk.h
> > > new file mode 100644
> > > index 0000000000..cdcc9e8534
> > > --- /dev/null
> > > +++ b/include/hw/misc/npcm7xx_clk.h
> > > @@ -0,0 +1,48 @@
> > > +/*
> > > + * Nuvoton NPCM7xx Clock Control Registers.
> > > + *
> > > + * Copyright 2020 Google LLC
> > > + *
> > > + * This program is free software; you can redistribute it and/or modify
> > > it
> > > + * under the terms of the GNU General Public License as published by the
> > > + * Free Software Foundation; either version 2 of the License, or
> > > + * (at your option) any later version.
> > > + *
> > > + * This program is distributed in the hope that 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.
> > > + */
> > > +#ifndef NPCM7XX_CLK_H
> > > +#define NPCM7XX_CLK_H
> > > +
> > > +#include "exec/memory.h"
> > > +#include "hw/sysbus.h"
> > > +
> > > +/*
> > > + * The reference clock frequency for the timer modules, and the SECCNT
> > > and
> > > + * CNTR25M registers in this module, is always 25 MHz.
> > > + */
> > > +#define NPCM7XX_TIMER_REF_HZ (25000000)
> > > +
> > > +/*
> > > + * Number of registers in our device state structure. Don't change this
> > > without
> > > + * incrementing the version_id in the vmstate.
> > > + */
> > > +#define NPCM7XX_CLK_NR_REGS (0x70 / sizeof(uint32_t))
> > > +
> > > +typedef struct NPCM7xxCLKState {
> > > + SysBusDevice parent;
> > > +
> > > + MemoryRegion iomem;
> > > +
> > > + uint32_t regs[NPCM7XX_CLK_NR_REGS];
> > > +
> > > + /* Time reference for SECCNT and CNTR25M, initialized by power on
> > > reset */
> > > + int64_t ref_ns;
> > > +} NPCM7xxCLKState;
> > > +
> > > +#define TYPE_NPCM7XX_CLK "npcm7xx-clk"
> > > +#define NPCM7XX_CLK(obj) OBJECT_CHECK(NPCM7xxCLKState, (obj),
> > > TYPE_NPCM7XX_CLK)
> > > +
> > > +#endif /* NPCM7XX_CLK_H */
> > > diff --git a/hw/misc/npcm7xx_clk.c b/hw/misc/npcm7xx_clk.c
> > > new file mode 100644
> > > index 0000000000..21ab4200d1
> > > --- /dev/null
> > > +++ b/hw/misc/npcm7xx_clk.c
> > > @@ -0,0 +1,266 @@
> > > +/*
> > > + * Nuvoton NPCM7xx Clock Control Registers.
> > > + *
> > > + * Copyright 2020 Google LLC
> > > + *
> > > + * This program is free software; you can redistribute it and/or modify
> > > it
> > > + * under the terms of the GNU General Public License as published by the
> > > + * Free Software Foundation; either version 2 of the License, or
> > > + * (at your option) any later version.
> > > + *
> > > + * This program is distributed in the hope that 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.
> > > + */
> > > +
> > > +#include "qemu/osdep.h"
> > > +
> > > +#include "hw/misc/npcm7xx_clk.h"
> > > +#include "migration/vmstate.h"
> > > +#include "qemu/error-report.h"
> > > +#include "qemu/log.h"
> > > +#include "qemu/module.h"
> > > +#include "qemu/timer.h"
> > > +#include "qemu/units.h"
> > > +#include "trace.h"
> > > +
> > > +#define PLLCON_LOKI BIT(31)
> > > +#define PLLCON_LOKS BIT(30)
> > > +#define PLLCON_PWDEN BIT(12)
> > > +
> > > +enum NPCM7xxCLKRegisters {
> > > + NPCM7XX_CLK_CLKEN1,
> > > + NPCM7XX_CLK_CLKSEL,
> > > + NPCM7XX_CLK_CLKDIV1,
> > > + NPCM7XX_CLK_PLLCON0,
> > > + NPCM7XX_CLK_PLLCON1,
> > > + NPCM7XX_CLK_SWRSTR,
> > > + NPCM7XX_CLK_IPSRST1 = 0x20 / sizeof(uint32_t),
> > > + NPCM7XX_CLK_IPSRST2,
> > > + NPCM7XX_CLK_CLKEN2,
> > > + NPCM7XX_CLK_CLKDIV2,
> > > + NPCM7XX_CLK_CLKEN3,
> > > + NPCM7XX_CLK_IPSRST3,
> > > + NPCM7XX_CLK_WD0RCR,
> > > + NPCM7XX_CLK_WD1RCR,
> > > + NPCM7XX_CLK_WD2RCR,
> > > + NPCM7XX_CLK_SWRSTC1,
> > > + NPCM7XX_CLK_SWRSTC2,
> > > + NPCM7XX_CLK_SWRSTC3,
> > > + NPCM7XX_CLK_SWRSTC4,
> > > + NPCM7XX_CLK_PLLCON2,
> > > + NPCM7XX_CLK_CLKDIV3,
> > > + NPCM7XX_CLK_CORSTC,
> > > + NPCM7XX_CLK_PLLCONG,
> > > + NPCM7XX_CLK_AHBCKFI,
> > > + NPCM7XX_CLK_SECCNT,
> > > + NPCM7XX_CLK_CNTR25M,
> > > + NPCM7XX_CLK_REGS_END,
> > > +};
> > > +
> > > +/*
> > > + * These reset values were taken from version 0.91 of the NPCM750R data
> > > sheet.
> > > + *
> > > + * All are loaded on power-up reset. CLKENx and SWRSTR should also be
> > > loaded on
> > > + * core domain reset, but this reset type is not yet supported by QEMU.
> > > + */
> > > +static const uint32_t cold_reset_values[NPCM7XX_CLK_NR_REGS] = {
> > > + [NPCM7XX_CLK_CLKEN1] = 0xffffffff,
> > > + [NPCM7XX_CLK_CLKSEL] = 0x004aaaaa,
> > > + [NPCM7XX_CLK_CLKDIV1] = 0x5413f855,
> > > + [NPCM7XX_CLK_PLLCON0] = 0x00222101 | PLLCON_LOKI,
> > > + [NPCM7XX_CLK_PLLCON1] = 0x00202101 | PLLCON_LOKI,
> > > + [NPCM7XX_CLK_IPSRST1] = 0x00001000,
> > > + [NPCM7XX_CLK_IPSRST2] = 0x80000000,
> > > + [NPCM7XX_CLK_CLKEN2] = 0xffffffff,
> > > + [NPCM7XX_CLK_CLKDIV2] = 0xaa4f8f9f,
> > > + [NPCM7XX_CLK_CLKEN3] = 0xffffffff,
> > > + [NPCM7XX_CLK_IPSRST3] = 0x03000000,
> > > + [NPCM7XX_CLK_WD0RCR] = 0xffffffff,
> > > + [NPCM7XX_CLK_WD1RCR] = 0xffffffff,
> > > + [NPCM7XX_CLK_WD2RCR] = 0xffffffff,
> > > + [NPCM7XX_CLK_SWRSTC1] = 0x00000003,
> > > + [NPCM7XX_CLK_PLLCON2] = 0x00c02105 | PLLCON_LOKI,
> > > + [NPCM7XX_CLK_CORSTC] = 0x04000003,
> > > + [NPCM7XX_CLK_PLLCONG] = 0x01228606 | PLLCON_LOKI,
> > > + [NPCM7XX_CLK_AHBCKFI] = 0x000000c8,
> > > +};
> > > +
> > > +static uint64_t npcm7xx_clk_read(void *opaque, hwaddr offset, unsigned
> > > size)
> > > +{
> > > + uint32_t reg = offset / sizeof(uint32_t);
> > > + NPCM7xxCLKState *s = opaque;
> > > + int64_t now_ns;
> > > + uint32_t value = 0;
> > > +
> > > + if (reg >= NPCM7XX_CLK_NR_REGS) {
> > > + qemu_log_mask(LOG_GUEST_ERROR,
> > > + "%s: offset 0x%04" HWADDR_PRIx " out of range\n",
> >
> > I find "out of range" not clear, but this might be the correct
> > terminology.
> >
> > > + __func__, offset);
> > > + return 0;
> > > + }
> > > +
> > > + switch (reg) {
> > > + case NPCM7XX_CLK_SWRSTR:
> > > + qemu_log_mask(LOG_GUEST_ERROR,
> > > + "%s: register @ 0x%04" HWADDR_PRIx " is
> > > write-only\n",
> > > + __func__, offset);
> > > + break;
> > > +
> > > + case NPCM7XX_CLK_SECCNT:
> > > + now_ns = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
> > > + value = (now_ns - s->ref_ns) / NANOSECONDS_PER_SECOND;
> > > + break;
> > > +
> > > + case NPCM7XX_CLK_CNTR25M:
> > > + now_ns = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
> > > + /*
> > > + * This register counts 25 MHz cycles, updating every 640 ns. It
> > > rolls
> > > + * over to zero every second.
> > > + *
> > > + * The 4 LSBs are always zero: (1e9 / 640) << 4 = 25000000.
> > > + */
> > > + value = (((now_ns - s->ref_ns) / 640) << 4) %
> > > NPCM7XX_TIMER_REF_HZ;
> > > + break;
> > > +
> > > + default:
> > > + value = s->regs[reg];
> > > + break;
> > > + };
> > > +
> > > + trace_npcm7xx_clk_read(offset, value);
> > > +
> > > + return value;
> > > +}
> > > +
> > > +static void npcm7xx_clk_write(void *opaque, hwaddr offset,
> > > + uint64_t v, unsigned size)
> > > +{
> > > + uint32_t reg = offset / sizeof(uint32_t);
> > > + NPCM7xxCLKState *s = opaque;
> > > + uint32_t value = v;
> > > +
> > > + trace_npcm7xx_clk_write(offset, value);
> > > +
> > > + if (reg >= NPCM7XX_CLK_NR_REGS) {
> > > + qemu_log_mask(LOG_GUEST_ERROR,
> > > + "%s: offset 0x%04" HWADDR_PRIx " out of range\n",
> > > + __func__, offset);
> > > + return;
> > > + }
> > > +
> > > + switch (reg) {
> > > + case NPCM7XX_CLK_SWRSTR:
> > > + qemu_log_mask(LOG_UNIMP, "%s: SW reset not implemented:
> > > 0x%02x\n",
> > > + __func__, value);
> >
> > Isn't this sufficient?
> >
> > qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET);
>
> It's not quite that easy; this register holds 4 bits, each of which
> maps to a separate register which defines the modules to reset. It's
> not that hard, but a little more than I'd like to add to the series at
> this point. I'll send a followup patch once the initial series is in.
Actually, I'm not sure if this would have any effect on being able to
reboot. Running with -d unimp shows:
reboot: Restarting system
npcm7xx_timer_write: WTCR write not implemented: 0x00000083
Reboot failed -- System halted
So we need to implement watchdog support, which is something we were
planning to do fairly soon.
> >
> > > + value = 0;
> > > + break;
> > > +
> > > + case NPCM7XX_CLK_PLLCON0:
> > > + case NPCM7XX_CLK_PLLCON1:
> > > + case NPCM7XX_CLK_PLLCON2:
> > > + case NPCM7XX_CLK_PLLCONG:
> > > + if (value & PLLCON_PWDEN) {
> > > + /* Power down -- clear lock and indicate loss of lock */
> > > + value &= ~PLLCON_LOKI;
> > > + value |= PLLCON_LOKS;
> > > + } else {
> > > + /* Normal mode -- assume always locked */
> > > + value |= PLLCON_LOKI;
> > > + /* Keep LOKS unchanged unless cleared by writing 1 */
> > > + if (value & PLLCON_LOKS) {
> > > + value &= ~PLLCON_LOKS;
> > > + } else {
> > > + value |= (value & PLLCON_LOKS);
> > > + }
> > > + }
> > > + break;
> > > +
> > > + case NPCM7XX_CLK_CNTR25M:
> > > + qemu_log_mask(LOG_GUEST_ERROR,
> > > + "%s: register @ 0x%04" HWADDR_PRIx " is
> > > read-only\n",
> > > + __func__, offset);
> > > + return;
> > > + }
> > > +
> > > + s->regs[reg] = value;
> > > +}
> > > +
> > > +static const struct MemoryRegionOps npcm7xx_clk_ops = {
> > > + .read = npcm7xx_clk_read,
> > > + .write = npcm7xx_clk_write,
> > > + .endianness = DEVICE_LITTLE_ENDIAN,
> > > + .valid = {
> > > + .min_access_size = 4,
> > > + .max_access_size = 4,
> > > + .unaligned = false,
> > > + },
> > > +};
> > > +
> > > +static void npcm7xx_clk_enter_reset(Object *obj, ResetType type)
> > > +{
> > > + NPCM7xxCLKState *s = NPCM7XX_CLK(obj);
> > > +
> > > + QEMU_BUILD_BUG_ON(sizeof(s->regs) != sizeof(cold_reset_values));
> > > +
> > > + switch (type) {
> > > + case RESET_TYPE_COLD:
> > > + memcpy(s->regs, cold_reset_values, sizeof(cold_reset_values));
> > > + s->ref_ns = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
> > > + return;
> > > + }
> > > +
> > > + /*
> > > + * A small number of registers need to be reset on a core domain
> > > reset,
> > > + * but no such reset type exists yet.
> > > + */
> > > + qemu_log_mask(LOG_UNIMP, "%s: reset type %d not implemented.",
> > > + __func__, type);
> >
> > Clean :)
> >
> > > +}
> > > +
> > > +static void npcm7xx_clk_init(Object *obj)
> > > +{
> > > + NPCM7xxCLKState *s = NPCM7XX_CLK(obj);
> > > +
> > > + memory_region_init_io(&s->iomem, obj, &npcm7xx_clk_ops, s,
> > > + TYPE_NPCM7XX_CLK, 4 * KiB);
> > > + sysbus_init_mmio(&s->parent, &s->iomem);
> > > +}
> > > +
> > > +static const VMStateDescription vmstate_npcm7xx_clk = {
> > > + .name = "npcm7xx-clk",
> > > + .version_id = 0,
> > > + .minimum_version_id = 0,
> > > + .fields = (VMStateField[]) {
> > > + VMSTATE_UINT32_ARRAY(regs, NPCM7xxCLKState, NPCM7XX_CLK_NR_REGS),
> >
> > Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> > Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
>
> Thank you!
>
> > > + VMSTATE_INT64(ref_ns, NPCM7xxCLKState),
> > > + VMSTATE_END_OF_LIST(),
> > > + },
> > > +};
> > > +
> > > +static void npcm7xx_clk_class_init(ObjectClass *klass, void *data)
> > > +{
> > > + ResettableClass *rc = RESETTABLE_CLASS(klass);
> > > + DeviceClass *dc = DEVICE_CLASS(klass);
> > > +
> > > + QEMU_BUILD_BUG_ON(NPCM7XX_CLK_REGS_END > NPCM7XX_CLK_NR_REGS);
> > > +
> > > + dc->desc = "NPCM7xx Clock Control Registers";
> > > + dc->vmsd = &vmstate_npcm7xx_clk;
> > > + rc->phases.enter = npcm7xx_clk_enter_reset;
> > > +}
> > > +
> > > +static const TypeInfo npcm7xx_clk_info = {
> > > + .name = TYPE_NPCM7XX_CLK,
> > > + .parent = TYPE_SYS_BUS_DEVICE,
> > > + .instance_size = sizeof(NPCM7xxCLKState),
> > > + .instance_init = npcm7xx_clk_init,
> > > + .class_init = npcm7xx_clk_class_init,
> > > +};
> > > +
> > > +static void npcm7xx_clk_register_type(void)
> > > +{
> > > + type_register_static(&npcm7xx_clk_info);
> > > +}
> > > +type_init(npcm7xx_clk_register_type);
> > > diff --git a/hw/misc/meson.build b/hw/misc/meson.build
> > > index 99ffb9f9e8..531cc31dcc 100644
> > > --- a/hw/misc/meson.build
> > > +++ b/hw/misc/meson.build
> > > @@ -51,6 +51,7 @@ softmmu_ss.add(when: 'CONFIG_IMX', if_true: files(
> > > softmmu_ss.add(when: 'CONFIG_MILKYMIST', if_true:
> > > files('milkymist-hpdmc.c', 'milkymist-pfpu.c'))
> > > softmmu_ss.add(when: 'CONFIG_MAINSTONE', if_true: files('mst_fpga.c'))
> > > softmmu_ss.add(when: 'CONFIG_NPCM7XX', if_true: files(
> > > + 'npcm7xx_clk.c',
> > > 'npcm7xx_gcr.c',
> > > ))
> > > softmmu_ss.add(when: 'CONFIG_OMAP', if_true: files(
> > > diff --git a/hw/misc/trace-events b/hw/misc/trace-events
> > > index dbf90db8ed..a010699b4f 100644
> > > --- a/hw/misc/trace-events
> > > +++ b/hw/misc/trace-events
> > > @@ -111,6 +111,10 @@ mos6522_set_sr_int(void) "set sr_int"
> > > mos6522_write(uint64_t addr, uint64_t val) "reg=0x%"PRIx64 "
> > > val=0x%"PRIx64
> > > mos6522_read(uint64_t addr, unsigned val) "reg=0x%"PRIx64 " val=0x%x"
> > >
> > > +# npcm7xx_clk.c
> > > +npcm7xx_clk_read(uint64_t offset, uint32_t value) " offset: 0x%04"
> > > PRIx64 " value: 0x%08" PRIx32
> > > +npcm7xx_clk_write(uint64_t offset, uint32_t value) "offset: 0x%04"
> > > PRIx64 " value: 0x%08" PRIx32
> > > +
> > > # npcm7xx_gcr.c
> > > npcm7xx_gcr_read(uint64_t offset, uint32_t value) " offset: 0x%04"
> > > PRIx64 " value: 0x%08" PRIx32
> > > npcm7xx_gcr_write(uint64_t offset, uint32_t value) "offset: 0x%04"
> > > PRIx64 " value: 0x%08" PRIx32
> > >