[U-Boot] [PATCH v1 1/2] WIP: serial: Introduce ->getinfo() callback

[Bin Meng]

Hi Andy,

On Sat, Sep 22, 2018 at 9:05 PM Andy Shevchenko
<andriy.shevchenko at linux.intel.com> wrote:
>
> TBD
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko at linux.intel.com>
> ---
>  drivers/serial/ns16550.c       | 14 ++++++++++++++
>  drivers/serial/serial-uclass.c | 21 +++++++++++++++++++++
>  include/common.h               |  3 +++
>  include/serial.h               | 14 ++++++++++++++
>  4 files changed, 52 insertions(+)
>
> diff --git a/drivers/serial/ns16550.c b/drivers/serial/ns16550.c
> index f9041aa626..a996446936 100644
> --- a/drivers/serial/ns16550.c
> +++ b/drivers/serial/ns16550.c
> @@ -334,6 +334,19 @@ static int ns16550_serial_setbrg(struct udevice *dev, int baudrate)
>         return 0;
>  }
>
> +static int ns16550_serial_getinfo(struct udevice *dev, struct serial_device_info *info)
> +{
> +       struct NS16550 *const com_port = dev_get_priv(dev);
> +       struct ns16550_platdata *plat = com_port->plat;
> +
> +       info->addr_space = 0;

This one is tricky. Looks current 8250 DT binding does not have a
property to describe the address space to be MMIO or PIO. I am not
sure what's the best option here.

> +       info->reg_width = 8;

For this one, I believe we can use "reg-io-width" property from device tree.

> +       info->reg_shift = plat->reg_shift;
> +       info->reg_offset = plat->reg_offset;
> +       info->addr = plat->base;
> +       return 0;
> +}
> +
>  int ns16550_serial_probe(struct udevice *dev)
>  {
>         struct NS16550 *const com_port = dev_get_priv(dev);
> @@ -440,6 +453,7 @@ const struct dm_serial_ops ns16550_serial_ops = {
>         .pending = ns16550_serial_pending,
>         .getc = ns16550_serial_getc,
>         .setbrg = ns16550_serial_setbrg,
> +       .getinfo = ns16550_serial_getinfo,
>  };
>
>  #if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)
> diff --git a/drivers/serial/serial-uclass.c b/drivers/serial/serial-uclass.c
> index ffdcae0931..4778302e8f 100644
> --- a/drivers/serial/serial-uclass.c
> +++ b/drivers/serial/serial-uclass.c
> @@ -304,6 +304,25 @@ int serial_setconfig(uint config)
>         return 0;
>  }
>
> +int serial_getinfo(struct serial_device_info *info)
> +{
> +       struct dm_serial_ops *ops;
> +
> +       if (!gd->cur_serial_dev)
> +               return -ENODEV;
> +
> +       if (!info)
> +               return -EINVAL;
> +
> +       info->baudrate = gd->baudrate;
> +
> +       ops = serial_get_ops(gd->cur_serial_dev);
> +       if (ops->getinfo)
> +               return ops->getinfo(gd->cur_serial_dev, info);
> +
> +       return -EINVAL;
> +}
> +
>  void serial_stdio_init(void)
>  {
>  }
> @@ -421,6 +440,8 @@ static int serial_post_probe(struct udevice *dev)
>         if (ops->loop)
>                 ops->loop += gd->reloc_off
>  #endif
> +       if (ops->getinfo)
> +               ops->getinfo += gd->reloc_off;
>  #endif
>         /* Set the baud rate */
>         if (ops->setbrg) {
> diff --git a/include/common.h b/include/common.h
> index 83b3bdc58d..0479f3eac1 100644
> --- a/include/common.h
> +++ b/include/common.h
> @@ -349,6 +349,8 @@ void smp_set_core_boot_addr(unsigned long addr, int corenr);
>  void smp_kick_all_cpus(void);
>
>  /* $(CPU)/serial.c */
> +struct serial_device_info;
> +
>  int    serial_init   (void);
>  void   serial_setbrg (void);
>  void   serial_putc   (const char);
> @@ -357,6 +359,7 @@ void        serial_puts   (const char *);
>  int    serial_getc   (void);
>  int    serial_tstc   (void);
>  int    serial_setconfig(uint config);
> +int    serial_getinfo(struct serial_device_info *info);
>
>  /* $(CPU)/speed.c */
>  int    get_clocks (void);
> diff --git a/include/serial.h b/include/serial.h
> index 020cd392e8..c73477b079 100644
> --- a/include/serial.h
> +++ b/include/serial.h
> @@ -111,6 +111,16 @@ enum serial_stop {
>                                 SERIAL_8_BITS << SERIAL_BITS_SHIFT | \
>                                 SERIAL_ONE_STOP << SERIAL_STOP_SHIFT
>
> +/* REVISIT: ACPI GAS specification implied */
> +struct serial_device_info {
> +       unsigned int baudrate;
> +       u8      addr_space; /* 0 - MMIO, 1 - IO */
> +       u8      reg_width;
> +       u8      reg_offset;
> +       u8      reg_shift;
> +       u64     addr;
> +};
> +
>  /**
>   * struct struct dm_serial_ops - Driver model serial operations
>   *
> @@ -201,6 +211,10 @@ struct dm_serial_ops {
>          * @return 0 if OK, -ve on error
>          */
>         int (*setconfig)(struct udevice *dev, uint serial_config);
> +       /**
> +        * getinfo() - Get serial device information
> +        */
> +       int (*getinfo)(struct udevice *dev, struct serial_device_info *info);
>  };

Generally this patch looks OK to me.

BTW: why doesn't the kernel use the 'earlycon' command line?

Regards,
Bin