Re: [Qemu-devel] [PATCH v2 1/3] xlnx-zynqmp-rtc: Initial commit

[Peter Maydell]

On 12 January 2018 at 22:36, Alistair Francis
<address@hidden> wrote:
> Initial commit of the ZynqMP RTC device.
>
> Signed-off-by: Alistair Francis <address@hidden>
> ---
> V2:
>  - Delete unused realise function
>  - Remove DB_PRINT()
>
>  hw/timer/Makefile.objs             |   1 +
>  hw/timer/xlnx-zynqmp-rtc.c         | 218 
> +++++++++++++++++++++++++++++++++++++
>  include/hw/timer/xlnx-zynqmp-rtc.h |  84 ++++++++++++++
>  3 files changed, 303 insertions(+)
>  create mode 100644 hw/timer/xlnx-zynqmp-rtc.c
>  create mode 100644 include/hw/timer/xlnx-zynqmp-rtc.h
>
> diff --git a/hw/timer/Makefile.objs b/hw/timer/Makefile.objs
> index 8c19eac3b6..8b27a4b7ef 100644
> --- a/hw/timer/Makefile.objs
> +++ b/hw/timer/Makefile.objs
> @@ -21,6 +21,7 @@ common-obj-$(CONFIG_IMX) += imx_epit.o
>  common-obj-$(CONFIG_IMX) += imx_gpt.o
>  common-obj-$(CONFIG_LM32) += lm32_timer.o
>  common-obj-$(CONFIG_MILKYMIST) += milkymist-sysctl.o
> +common-obj-$(CONFIG_XLNX_ZYNQMP) += xlnx-zynqmp-rtc.o
>
>  obj-$(CONFIG_ALTERA_TIMER) += altera_timer.o
>  obj-$(CONFIG_EXYNOS4) += exynos4210_mct.o
> diff --git a/hw/timer/xlnx-zynqmp-rtc.c b/hw/timer/xlnx-zynqmp-rtc.c
> new file mode 100644
> index 0000000000..ead40fc42d
> --- /dev/null
> +++ b/hw/timer/xlnx-zynqmp-rtc.c
> @@ -0,0 +1,218 @@
> +/*
> + * QEMU model of the Xilinx ZynqMP Real Time Clock (RTC).
> + *
> + * Copyright (c) 2017 Xilinx Inc.
> + *
> + * Written-by: Alistair Francis <address@hidden>
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a 
> copy
> + * of this software and associated documentation files (the "Software"), to 
> deal
> + * in the Software without restriction, including without limitation the 
> rights
> + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
> + * copies of the Software, and to permit persons to whom the Software is
> + * furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
> FROM,
> + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
> + * THE SOFTWARE.
> + */
> +
> +#include "qemu/osdep.h"
> +#include "hw/sysbus.h"
> +#include "hw/register.h"
> +#include "qemu/bitops.h"
> +#include "qemu/log.h"
> +#include "hw/timer/xlnx-zynqmp-rtc.h"
> +
> +#ifndef XLNX_ZYNQMP_RTC_ERR_DEBUG
> +#define XLNX_ZYNQMP_RTC_ERR_DEBUG 0
> +#endif

This #define doesn't seem to be used, or have I missed it?

> +
> +static void rtc_int_update_irq(XlnxZynqMPRTC *s)
> +{
> +    bool pending = s->regs[R_RTC_INT_STATUS] & ~s->regs[R_RTC_INT_MASK];
> +    qemu_set_irq(s->irq_rtc_int, pending);
> +}
> +
> +static void addr_error_int_update_irq(XlnxZynqMPRTC *s)
> +{
> +    bool pending = s->regs[R_ADDR_ERROR] & ~s->regs[R_ADDR_ERROR_INT_MASK];
> +    qemu_set_irq(s->irq_addr_error_int, pending);
> +}
> +
> +static void rtc_int_status_postw(RegisterInfo *reg, uint64_t val64)
> +{
> +    XlnxZynqMPRTC *s = XLNX_ZYNQMP_RTC(reg->opaque);
> +    rtc_int_update_irq(s);
> +}
> +
> +static uint64_t rtc_int_en_prew(RegisterInfo *reg, uint64_t val64)
> +{
> +    XlnxZynqMPRTC *s = XLNX_ZYNQMP_RTC(reg->opaque);
> +    uint32_t val = val64;
> +
> +    s->regs[R_RTC_INT_MASK] &= ~val;
> +    rtc_int_update_irq(s);
> +    return 0;
> +}

I have to say I find all this pre-write/post-write stuff confusing
compared to just having a straightforward pair of read and write functions
for the device. Why do we update the interrupt state in a post-write
for the status register but a pre-write for the int_en register ?



> +static void rtc_reset(DeviceState *dev)
> +{
> +    XlnxZynqMPRTC *s = XLNX_ZYNQMP_RTC(dev);
> +    unsigned int i;
> +
> +    for (i = 0; i < ARRAY_SIZE(s->regs_info); ++i) {
> +        register_reset(&s->regs_info[i]);
> +    }
> +
> +    rtc_int_update_irq(s);
> +    addr_error_int_update_irq(s);
> +}

Updating irq lines in reset functions is a bit dubious.
(We really should figure out how to do that properly some day.)

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You probably don't really mean this :-)  Can you fix your email
config for sending patch mails, please?

thanks
-- PMM