[U-Boot] [PATCH] nios2: convert altera_uart to driver model

[Marek Vasut]

On Friday, September 18, 2015 at 05:24:18 AM, Thomas Chou wrote:
> Convert altera_uart to driver model.
> 
> Signed-off-by: Thomas Chou <thomas at wytron.com.tw>
> ---

Hi!

minor nitpicks below :)

> -typedef volatile struct {
> +struct altera_uart_regs {
>  	unsigned	rxdata;		/* Rx data reg */
>  	unsigned	txdata;		/* Tx data reg */
>  	unsigned	status;		/* Status reg */
>  	unsigned	control;	/* Control reg */
>  	unsigned	divisor;	/* Baud rate divisor reg */
>  	unsigned	endofpacket;	/* End-of-packet reg */

Probably make this u32 instead of unsigned, so we're in the safe.

> -} nios_uart_t;
> +};

[...]

> -static int altera_serial_init(void)
> +static int altera_uart_putc(struct udevice *dev, const char c)
>  {
> -	return 0;
> -}
> +	struct altera_uart_platdata *plat = dev->platdata;
> +	struct altera_uart_regs *const regs = plat->reg;
> 
> -#else
> +	if (!(readl(&regs->status) & NIOS_UART_TRDY))
> +		return -EAGAIN;
> 
> -static void altera_serial_setbrg(void)
> -{
> -	unsigned div;
> +	writel((unsigned char)c, &regs->txdata);

Is this type-cast needed ?

> -	div = (CONFIG_SYS_CLK_FREQ/gd->baudrate)-1;
> -	writel (div, &uart->divisor);
> +	return 0;
>  }
> 
> -static int altera_serial_init(void)
> +static int altera_uart_pending(struct udevice *dev, bool input)
>  {
> -	serial_setbrg();
> -	return 0;
> +	struct altera_uart_platdata *plat = dev->platdata;
> +	struct altera_uart_regs *const regs = plat->reg;
> +	unsigned st = readl(&regs->status);
> +
> +	if (input)
> +		return (st & NIOS_UART_RRDY) ? 1 : 0;
> +	else
> +		return (st & NIOS_UART_TMT) ? 0 : 1;

Drop the ternary please, just use return st & flag or return !(st & flag),
it's not necessary to return 0 or 1, you can safely return 0 or non-zero.

>  }
> 
> -#endif /* CONFIG_SYS_NIOS_FIXEDBAUD */
> -
> -/*-----------------------------------------------------------------------
> - * UART CONSOLE
> - *---------------------------------------------------------------------*/
> -static void altera_serial_putc(char c)
> +static int altera_uart_getc(struct udevice *dev)
>  {
> -	if (c == '\n')
> -		serial_putc ('\r');
> -	while ((readl (&uart->status) & NIOS_UART_TRDY) == 0)
> -		WATCHDOG_RESET ();
> -	writel ((unsigned char)c, &uart->txdata);
> +	struct altera_uart_platdata *plat = dev->platdata;
> +	struct altera_uart_regs *const regs = plat->reg;
> +
> +	if (readl(&regs->status) & NIOS_UART_RRDY)
> +		return (readl(&regs->rxdata) & 0xff);

Parenthesis not needed around the readl(...) & 0xff expression.

> +	else
> +		return -EAGAIN;
>  }

[...]

Thanks!