On 9/28/20 10:45 AM, Luc Michel wrote:
> On 23:05 Sat 26 Sep , Philippe Mathieu-Daudé wrote:
>> On 9/25/20 12:17 PM, Luc Michel wrote:
>>> The BCM2835 cprman is the clock manager of the SoC. It is composed of a
>>
>> Can we use CPRMAN in caps?
>>
>>> main oscillator, and several sub-components (PLLs, multiplexers, ...) to
>>> generate the BCM2835 clock tree.
>>>
>>> This commit adds a skeleton of the cprman, with a dummy register
>>> read/write implementation. It embeds the main oscillator (xosc) from
>>> which all the clocks will be derived.
>>>
>>> Signed-off-by: Luc Michel <l...@lmichel.fr>
>>> ---
>>> include/hw/arm/bcm2835_peripherals.h | 3 +-
>>> include/hw/misc/bcm2835_cprman.h | 37 +++++
>>> include/hw/misc/bcm2835_cprman_internals.h | 24 +++
>>> hw/arm/bcm2835_peripherals.c | 11 +-
>>> hw/misc/bcm2835_cprman.c | 171 +++++++++++++++++++++
>>> hw/misc/meson.build | 1 +
>>> hw/misc/trace-events | 5 +
>>> 7 files changed, 250 insertions(+), 2 deletions(-)
>>> create mode 100644 include/hw/misc/bcm2835_cprman.h
>>> create mode 100644 include/hw/misc/bcm2835_cprman_internals.h
>>> create mode 100644 hw/misc/bcm2835_cprman.c
>>>
>>> diff --git a/include/hw/arm/bcm2835_peripherals.h
>>> b/include/hw/arm/bcm2835_peripherals.h
>>> index 199088425a..002bb5e73b 100644
>>> --- a/include/hw/arm/bcm2835_peripherals.h
>>> +++ b/include/hw/arm/bcm2835_peripherals.h
>>> @@ -21,10 +21,11 @@
>>> #include "hw/misc/bcm2835_property.h"
>>> #include "hw/misc/bcm2835_rng.h"
>>> #include "hw/misc/bcm2835_mbox.h"
>>> #include "hw/misc/bcm2835_mphi.h"
>>> #include "hw/misc/bcm2835_thermal.h"
>>> +#include "hw/misc/bcm2835_cprman.h"
>>> #include "hw/sd/sdhci.h"
>>> #include "hw/sd/bcm2835_sdhost.h"
>>> #include "hw/gpio/bcm2835_gpio.h"
>>> #include "hw/timer/bcm2835_systmr.h"
>>> #include "hw/usb/hcd-dwc2.h"
>>> @@ -45,11 +46,11 @@ struct BCM2835PeripheralState {
>>>
>>> BCM2835SystemTimerState systmr;
>>> BCM2835MphiState mphi;
>>> UnimplementedDeviceState armtmr;
>>> UnimplementedDeviceState powermgt;
>>> - UnimplementedDeviceState cprman;
>>> + BCM2835CprmanState cprman;
>>> PL011State uart0;
>>> BCM2835AuxState aux;
>>> BCM2835FBState fb;
>>> BCM2835DMAState dma;
>>> BCM2835ICState ic;
>>> diff --git a/include/hw/misc/bcm2835_cprman.h
>>> b/include/hw/misc/bcm2835_cprman.h
>>> new file mode 100644
>>> index 0000000000..de9bd01b23
>>> --- /dev/null
>>> +++ b/include/hw/misc/bcm2835_cprman.h
>>> @@ -0,0 +1,37 @@
>>> +/*
>>> + * BCM2835 cprman clock manager
>>> + *
>>> + * Copyright (c) 2020 Luc Michel <l...@lmichel.fr>
>>> + *
>>> + * SPDX-License-Identifier: GPL-2.0-or-later
>>> + */
>>> +
>>> +#ifndef HW_MISC_CPRMAN_H
>>> +#define HW_MISC_CPRMAN_H
>>> +
>>> +#include "hw/sysbus.h"
>>> +#include "hw/qdev-clock.h"
>>> +
>>> +#define TYPE_BCM2835_CPRMAN "bcm2835-cprman"
>>> +
>>> +typedef struct BCM2835CprmanState BCM2835CprmanState;
>>> +
>>> +DECLARE_INSTANCE_CHECKER(BCM2835CprmanState, CPRMAN,
>>> + TYPE_BCM2835_CPRMAN)
>>> +
>>> +#define CPRMAN_NUM_REGS (0x2000 / sizeof(uint32_t))
>>> +
>>> +struct BCM2835CprmanState {
>>> + /*< private >*/
>>> + SysBusDevice parent_obj;
>>> +
>>> + /*< public >*/
>>> + MemoryRegion iomem;
>>> +
>>> + uint32_t regs[CPRMAN_NUM_REGS];
>>> + uint32_t xosc_freq;
>>> +
>>> + Clock *xosc;
Isn't it xosc external to the CPRMAN?
>>> +};
>>> +
>>> +#endif
>>> diff --git a/include/hw/misc/bcm2835_cprman_internals.h
>>> b/include/hw/misc/bcm2835_cprman_internals.h
>>> new file mode 100644
>>> index 0000000000..6a10b60930
>>> --- /dev/null
>>> +++ b/include/hw/misc/bcm2835_cprman_internals.h
>>> @@ -0,0 +1,24 @@
>>> +/*
>>> + * BCM2835 cprman clock manager
>>> + *
>>> + * Copyright (c) 2020 Luc Michel <l...@lmichel.fr>
>>> + *
>>> + * SPDX-License-Identifier: GPL-2.0-or-later
>>> + */
>>> +
>>> +#ifndef HW_MISC_CPRMAN_INTERNALS_H
>>> +#define HW_MISC_CPRMAN_INTERNALS_H
>>> +
>>> +#include "hw/registerfields.h"
>>> +#include "hw/misc/bcm2835_cprman.h"
>>> +
>>> +/* Register map */
>>> +
>>> +/*
>>> + * This field is common to all registers. Each register write value must
>>> match
>>> + * the CPRMAN_PASSWORD magic value in its 8 MSB.
>>> + */
>>> +FIELD(CPRMAN, PASSWORD, 24, 8)
>>> +#define CPRMAN_PASSWORD 0x5a
>>
>> s/PASSWORD/KEY/?
> I'm not a big fan of this name either, but this is actually how this
> field is named in the datasheet and in various sources.
>
> See:
> -
> https://www.raspberrypi.org/app/uploads/2012/02/BCM2835-ARM-Peripherals.pdf
> (page 107)
> - https://elinux.org/BCM2835_registers#CM (auto-generated from
> Broadcom GPU related code)
> - The Linux driver also use this name FWIW.
OK.
>>
>>> +
>>> +#endif
>>> diff --git a/hw/arm/bcm2835_peripherals.c b/hw/arm/bcm2835_peripherals.c
>>> index f0802c91e0..958aadeeb9 100644
>>> --- a/hw/arm/bcm2835_peripherals.c
>>> +++ b/hw/arm/bcm2835_peripherals.c
>>> @@ -119,10 +119,13 @@ static void bcm2835_peripherals_init(Object *obj)
>>> object_initialize_child(obj, "mphi", &s->mphi, TYPE_BCM2835_MPHI);
>>>
>>> /* DWC2 */
>>> object_initialize_child(obj, "dwc2", &s->dwc2, TYPE_DWC2_USB);
>>>
>>> + /* CPRMAN clock manager */
>>> + object_initialize_child(obj, "cprman", &s->cprman,
>>> TYPE_BCM2835_CPRMAN);
>>> +
>>> object_property_add_const_link(OBJECT(&s->dwc2), "dma-mr",
>>> OBJECT(&s->gpu_bus_mr));
>>> }
>>>
>>> static void bcm2835_peripherals_realize(DeviceState *dev, Error **errp)
>>> @@ -158,10 +161,17 @@ static void bcm2835_peripherals_realize(DeviceState
>>> *dev, Error **errp)
>>> /* Interrupt Controller */
>>> if (!sysbus_realize(SYS_BUS_DEVICE(&s->ic), errp)) {
>>> return;
>>> }
>>>
>>> + /* CPRMAN clock manager */
>>> + if (!sysbus_realize(SYS_BUS_DEVICE(&s->cprman), errp)) {
>>> + return;
>>> + }
>>> + memory_region_add_subregion(&s->peri_mr, CPRMAN_OFFSET,
>>> + sysbus_mmio_get_region(SYS_BUS_DEVICE(&s->cprman), 0));
>>> +
>>> memory_region_add_subregion(&s->peri_mr, ARMCTRL_IC_OFFSET,
>>> sysbus_mmio_get_region(SYS_BUS_DEVICE(&s->ic), 0));
>>> sysbus_pass_irq(SYS_BUS_DEVICE(s), SYS_BUS_DEVICE(&s->ic));
>>>
>>> /* Sys Timer */
>>> @@ -343,11 +353,10 @@ static void bcm2835_peripherals_realize(DeviceState
>>> *dev, Error **errp)
>>> qdev_get_gpio_in_named(DEVICE(&s->ic), BCM2835_IC_GPU_IRQ,
>>> INTERRUPT_USB));
>>>
>>> create_unimp(s, &s->armtmr, "bcm2835-sp804", ARMCTRL_TIMER0_1_OFFSET,
>>> 0x40);
>>> create_unimp(s, &s->powermgt, "bcm2835-powermgt", PM_OFFSET, 0x114);
>>> - create_unimp(s, &s->cprman, "bcm2835-cprman", CPRMAN_OFFSET, 0x2000);
>>> create_unimp(s, &s->i2s, "bcm2835-i2s", I2S_OFFSET, 0x100);
>>> create_unimp(s, &s->smi, "bcm2835-smi", SMI_OFFSET, 0x100);
>>> create_unimp(s, &s->spi[0], "bcm2835-spi0", SPI0_OFFSET, 0x20);
>>> create_unimp(s, &s->bscsl, "bcm2835-spis", BSC_SL_OFFSET, 0x100);
>>> create_unimp(s, &s->i2c[0], "bcm2835-i2c0", BSC0_OFFSET, 0x20);
>>> diff --git a/hw/misc/bcm2835_cprman.c b/hw/misc/bcm2835_cprman.c
>>> new file mode 100644
>>> index 0000000000..d2ea0c9236
>>> --- /dev/null
>>> +++ b/hw/misc/bcm2835_cprman.c
>>> @@ -0,0 +1,171 @@
>>> +/*
>>> + * BCM2835 cprman clock manager
>>> + *
>>> + * Copyright (c) 2020 Luc Michel <l...@lmichel.fr>
>>> + *
>>> + * SPDX-License-Identifier: GPL-2.0-or-later
>>> + */
>>> +
>>> +/*
>>> + * This peripheral is roughly divided into 3 main parts:
>>> + * - the PLLs
>>> + * - the PLL channels
>>> + * - the clock muxes
>>> + *
>>> + * A main oscillator (xosc) feeds all the PLLs. Each PLLs has one or more
>>> + * channels. Those channel are then connected to the clock muxes. Each mux
>>> has
>>> + * multiples sources (usually the xosc, some of the PLL channels and some
>>> "test
>>> + * debug" clocks). It can selects one or the other through a control
>>> register.
>>
>> "It" is unclear (to me) in this sentence. Assuming the mux.
>>
>>> + * Each mux has one output clock that also goes out of the CPRMAN. It
>>> usually
>>
>> Here is "It" the mux or the output clock? Assuming the mux.
>>
>>> + * connects to another peripheral in the SoC (so a given mux is dedicated
>>> to a
>>> + * peripheral).
>>> + *
>>> + * At each level (PLL, channel and mux), the clock can be altered through
>>> + * dividers (and multipliers in case of the PLLs), and can be disabled (in
>>> this
>>> + * case, the next levels see no clock).
>>> + *
>>> + * This can be sum-up as follows (this is an example and not the actual
>>> BCM2835
>>> + * clock tree):
>>> + *
>>> + * /-->[PLL]-|->[PLL channel]--... [mux]--> to
>>> peripherals
>>> + * | |->[PLL channel] muxes takes [mux]
>>> + * | \->[PLL channel] inputs from [mux]
>>> + * | some channels [mux]
>>> + * [xosc]---|-->[PLL]-|->[PLL channel] and other srcs [mux]
>>> + * | \->[PLL channel] ...-->[mux]
>>> + * | [mux]
>>> + * \-->[PLL]--->[PLL channel] [mux]
>>> + *
>>> + * The page at https://elinux.org/The_Undocumented_Pi gives the actual
>>> clock
>>> + * tree configuration.
>>> + */
>>> +
>>> +#include "qemu/osdep.h"
>>> +#include "qemu/log.h"
>>> +#include "migration/vmstate.h"
>>> +#include "hw/qdev-properties.h"
>>> +#include "hw/misc/bcm2835_cprman.h"
>>> +#include "hw/misc/bcm2835_cprman_internals.h"
>>> +#include "trace.h"
>>> +
>>> +/* CPRMAN "top level" model */
>>> +
>>> +static uint64_t cprman_read(void *opaque, hwaddr offset,
>>> + unsigned size)
>>
>> Indent off.
>>
>>> +{
>>> + BCM2835CprmanState *s = CPRMAN(opaque);
>>> + uint64_t r = 0;
>>> + size_t idx = offset / sizeof(uint32_t);
>>> +
>>> + switch (idx) {
>>> + default:
>>> + r = s->regs[idx];
>>> + }
>>> +
>>> + trace_bcm2835_cprman_read(offset, r);
>>> + return r;
>>> +}
>>> +
>>> +static void cprman_write(void *opaque, hwaddr offset,
>>> + uint64_t value, unsigned size)
>>> +{
>>> + BCM2835CprmanState *s = CPRMAN(opaque);
>>> + size_t idx = offset / sizeof(uint32_t);
>>> +
>>> + if (FIELD_EX32(value, CPRMAN, PASSWORD) != CPRMAN_PASSWORD) {
>>> + trace_bcm2835_cprman_write_invalid_magic(offset, value);
>>> + return;
>>> + }
>>> +
>>> + value &= ~R_CPRMAN_PASSWORD_MASK;
>>> +
>>> + trace_bcm2835_cprman_write(offset, value);
>>> + s->regs[idx] = value;
>>> +
>>> +}
>>> +
>>> +static const MemoryRegionOps cprman_ops = {
>>> + .read = cprman_read,
>>> + .write = cprman_write,
>>> + .endianness = DEVICE_LITTLE_ENDIAN,
>>> + .valid = {
>>> + .min_access_size = 4,
>>> + .max_access_size = 4,
>>
>> I couldn't find this in the public datasheets (any pointer?).
>>
>> Since your implementation is 32bit, can you explicit .impl
>> min/max = 4?
>
> I could not find this information either, but I assumed this is the
> case, mainly because of the 'PASSWORD' field in all registers.
Good point. Do you mind adding a comment about it here please?
>
> Regarding .impl, I thought that having .valid was enough?
Until we eventually figure out we can do 64-bit accesses,
so someone change .valid.max to 8 and your model is broken :/
>
>>
>>> + .unaligned = false,
>>> + },
>>> +};
>>> +
>>> +static void cprman_reset(DeviceState *dev)
>>> +{
>>> + BCM2835CprmanState *s = CPRMAN(dev);
>>> +
>>> + memset(s->regs, 0, sizeof(s->regs));
>>> +
>>> + clock_update_hz(s->xosc, s->xosc_freq);
>>> +}
>>> +
>>> +static Clock *init_internal_clock(BCM2835CprmanState *s,
>>> + const char *name)
>>
>> Interesting. Shouldn't this be a public function from the
>> Clock API? (Taking Object + name arguments)?
>>
> Yes, I hesitated to do just that. I'll add a patch for it when I re-roll.
>>> +{
>>> + Object *obj;
>>> + Clock *clk;
>>> +
>>> + obj = object_new(TYPE_CLOCK);
>>> + object_property_add_child(OBJECT(s), name, obj);
>>> + object_unref(obj);
>>> +
>>> + clk = CLOCK(obj);
>>> + clock_setup_canonical_path(clk);
>>> +
>>> + return clk;
>>> +}
>>> +
>>> +static void cprman_init(Object *obj)
>>> +{
>>> + BCM2835CprmanState *s = CPRMAN(obj);
>>> +
>>> + s->xosc = init_internal_clock(s, "xosc");
>>> +
>>> + memory_region_init_io(&s->iomem, obj, &cprman_ops,
>>> + s, "bcm2835-cprman", 0x2000);
>>
>> Again assuming this is a 8KB MMIO device:
>>
>> Reviewed-by: Philippe Mathieu-Daudé <f4...@amsat.org>
>
> Thanks!
>
