Re: [PATCH 20/21] hw/i2c: Import TCA6416 emulation from Xilinx

[Bernhard Beschow <shentey@gmail.com>]

Am 21. Januar 2025 03:07:39 UTC schrieb BALATON Zoltan <balaton@eik.bme.hu>:
>On Mon, 20 Jan 2025, Bernhard Beschow wrote:
>> Xilinx QEMU implements a TCA6416 device model which may be useful for the
>> broader QEMU community, so upstream it. In the Xilinx fork, the device model
>> gets compiled whenever CONFIG_CADENCE is true, so have it maintained by the
>> "hw/*/cadence_*" maintainers.
>> 
>> The code is based on Xilinx QEMU version xilinx_v2024.2 plus the following
>> modifications:
>> * Use OBJECT_DECLARE_SIMPLE_TYPE()
>> * Port from DPRINTF() to trace events
>> * Follow QEMU conventions for naming of state struct
>> * Rename type to not contain a ','
>> * Use DEFINE_TYPES() macro
>> * Implement under hw/gpio since device is i2c client and gpio provider
>> * Have dedicated Kconfig switch
>> 
>> Signed-off-by: Bernhard Beschow <shentey@gmail.com>
>> 
>> --
>> I have a use for TCA6416 emulation. Question: Are Xilinx Zynq maintainers
>> willing to maintain this device model?
>> ---
>> MAINTAINERS          |   1 +
>> hw/gpio/tca6416.c    | 122 +++++++++++++++++++++++++++++++++++++++++++
>> hw/gpio/Kconfig      |   5 ++
>> hw/gpio/meson.build  |   1 +
>> hw/gpio/trace-events |   4 ++
>> 5 files changed, 133 insertions(+)
>> create mode 100644 hw/gpio/tca6416.c
>> 
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index 7531d65429..0cac9c90bc 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -1030,6 +1030,7 @@ S: Maintained
>> F: hw/*/xilinx_*
>> F: hw/*/cadence_*
>> F: hw/misc/zynq_slcr.c
>> +F: hw/gpio/tca6416.c
>> F: hw/adc/zynq-xadc.c
>> F: include/hw/misc/zynq_slcr.h
>> F: include/hw/adc/zynq-xadc.h
>> diff --git a/hw/gpio/tca6416.c b/hw/gpio/tca6416.c
>> new file mode 100644
>> index 0000000000..81ed7a654d
>> --- /dev/null
>> +++ b/hw/gpio/tca6416.c
>> @@ -0,0 +1,122 @@
>> +/*
>> + * QEMU model of TCA6416 16-Bit I/O Expander
>> + *
>> + * Copyright (c) 2018 Xilinx Inc.
>> + *
>> + * Written by Sai Pavan Boddu <sai.pavan.boddu@xilinx.com>
>> + *
>> + * 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/i2c/i2c.h"
>> +#include "trace.h"
>> +
>> +#define TYPE_TCA6416 "tca6416"
>> +OBJECT_DECLARE_SIMPLE_TYPE(Tca6416State, TCA6416)
>> +
>> +#define IN_PORT0    0
>> +#define IN_PORT1    1
>> +#define OUT_PORT0   2
>> +#define OUT_PORT1   3
>> +#define POL_INV0    4
>> +#define POL_INV1    5
>> +#define CONF_PORT0  6
>> +#define CONF_PORT1  7
>> +#define RMAX (CONF_PORT1 + 1)
>
>Maybe make this list an enum? (But also fine as it is.)

Good idea indeed. I'd address this once maintainership is clarified.

Best regards,
Bernhard

>
>Regards,
>BALATON Zoltan
>
>> +
>> +enum tca6416_events {
>> +     ADDR_DONE,
>> +     ADDRESSING,
>> +};
>> +
>> +struct Tca6416State {
>> +     I2CSlave i2c;
>> +
>> +     uint8_t addr;
>> +     uint8_t state;
>> +     uint8_t regs[RMAX];
>> +};
>> +
>> +static uint8_t tca6416_read(I2CSlave *i2c)
>> +{
>> +    Tca6416State *s = TCA6416(i2c);
>> +    uint8_t ret;
>> +
>> +    ret = s->regs[s->addr];
>> +    trace_tca6416_read(ret);
>> +    return ret;
>> +}
>> +
>> +static int tca6416_write(I2CSlave *i2c, uint8_t data)
>> +{
>> +    Tca6416State *s = TCA6416(i2c);
>> +
>> +    trace_tca6416_write(data);
>> +    if (s->state == ADDRESSING) {
>> +        s->addr = data;
>> +    } else {
>> +        s->regs[s->addr] = data;
>> +    }
>> +
>> +    return 0;
>> +}
>> +
>> +static void tca6416_realize(DeviceState *dev, Error **errp)
>> +{
>> +    Tca6416State *s = TCA6416(dev);
>> +
>> +    s->regs[CONF_PORT0] = 0xFF;
>> +    s->regs[CONF_PORT1] = 0xFF;
>> +}
>> +
>> +static int tca6416_event(I2CSlave *i2c, enum i2c_event event)
>> +{
>> +    Tca6416State *s = TCA6416(i2c);
>> +
>> +    switch (event) {
>> +    case I2C_START_SEND:
>> +        s->state = ADDRESSING;
>> +        break;
>> +    default:
>> +         s->state = ADDR_DONE;
>> +    };
>> +    return 0;
>> +}
>> +
>> +static void tca6416_class_init(ObjectClass *klass, void *data)
>> +{
>> +    DeviceClass *dc = DEVICE_CLASS(klass);
>> +    I2CSlaveClass *k = I2C_SLAVE_CLASS(klass);
>> +
>> +    dc->realize = tca6416_realize;
>> +    k->recv = tca6416_read;
>> +    k->send = tca6416_write;
>> +    k->event = tca6416_event;
>> +}
>> +
>> +static const TypeInfo tca6416_types[] = {
>> +    {
>> +        .name = TYPE_TCA6416,
>> +        .parent = TYPE_I2C_SLAVE,
>> +        .class_init = tca6416_class_init,
>> +        .instance_size = sizeof(Tca6416State),
>> +    }
>> +};
>> +
>> +DEFINE_TYPES(tca6416_types)
>> diff --git a/hw/gpio/Kconfig b/hw/gpio/Kconfig
>> index c423e10f59..a240cf2de2 100644
>> --- a/hw/gpio/Kconfig
>> +++ b/hw/gpio/Kconfig
>> @@ -20,5 +20,10 @@ config PCF8574
>>     bool
>>     depends on I2C
>> 
>> +config TCA6416
>> +    bool
>> +    depends on I2C
>> +    default y if I2C_DEVICES
>> +
>> config ZAURUS_SCOOP
>>     bool
>> diff --git a/hw/gpio/meson.build b/hw/gpio/meson.build
>> index 74840619c0..b3ff7c7460 100644
>> --- a/hw/gpio/meson.build
>> +++ b/hw/gpio/meson.build
>> @@ -18,3 +18,4 @@ system_ss.add(when: 'CONFIG_STM32L4X5_SOC', if_true: files('stm32l4x5_gpio.c'))
>> system_ss.add(when: 'CONFIG_ASPEED_SOC', if_true: files('aspeed_gpio.c'))
>> system_ss.add(when: 'CONFIG_SIFIVE_GPIO', if_true: files('sifive_gpio.c'))
>> system_ss.add(when: 'CONFIG_PCF8574', if_true: files('pcf8574.c'))
>> +system_ss.add(when: 'CONFIG_TCA6416', if_true: files('tca6416.c'))
>> diff --git a/hw/gpio/trace-events b/hw/gpio/trace-events
>> index cea896b28f..6724f2efb8 100644
>> --- a/hw/gpio/trace-events
>> +++ b/hw/gpio/trace-events
>> @@ -46,3 +46,7 @@ stm32l4x5_gpio_read(char *gpio, uint64_t addr) "GPIO%s addr: 0x%" PRIx64 " "
>> stm32l4x5_gpio_write(char *gpio, uint64_t addr, uint64_t data) "GPIO%s addr: 0x%" PRIx64 " val: 0x%" PRIx64 ""
>> stm32l4x5_gpio_update_idr(char *gpio, uint32_t old_idr, uint32_t new_idr) "GPIO%s from: 0x%x to: 0x%x"
>> stm32l4x5_gpio_pins(char *gpio, uint16_t disconnected, uint16_t high) "GPIO%s disconnected pins: 0x%x levels: 0x%x"
>> +
>> +# tca6416.c
>> +tca6416_write(uint8_t value) "0x%02x"
>> +tca6416_read(uint8_t value) "0x%02x"
>>