Re: [PATCH 2/5] serial: sprd: Use readable macros instead of magic number

[Chunyan Zhang]

On 11 August 2018 at 09:34, Baolin Wang <baolin.wang@xxxxxxxxxx> wrote:
> Define readable macros instead of magic number to make code more readable.
>
> Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxx>

Acked-by: Chunyan Zhang <chunyan.zhang@xxxxxxxxxxxxxx>

> ---
>  drivers/tty/serial/sprd_serial.c | 25 +++++++++++++++++--------
>  1 file changed, 17 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/tty/serial/sprd_serial.c b/drivers/tty/serial/sprd_serial.c
> index 1b0e3fb..e18d8af 100644
> --- a/drivers/tty/serial/sprd_serial.c
> +++ b/drivers/tty/serial/sprd_serial.c
> @@ -45,6 +45,8 @@
>
>  /* data number in TX and RX fifo */
>  #define SPRD_STS1              0x000C
> +#define SPRD_RX_FIFO_CNT_MASK  GENMASK(7, 0)
> +#define SPRD_TX_FIFO_CNT_MASK  GENMASK(15, 8)
>
>  /* interrupt enable register and its BITs */
>  #define SPRD_IEN               0x0010
> @@ -82,11 +84,15 @@
>  /* fifo threshold register */
>  #define SPRD_CTL2              0x0020
>  #define THLD_TX_EMPTY  0x40
> +#define THLD_TX_EMPTY_SHIFT    8
>  #define THLD_RX_FULL   0x40
>
>  /* config baud rate register */
>  #define SPRD_CLKD0             0x0024
> +#define SPRD_CLKD0_MASK                GENMASK(15, 0)
>  #define SPRD_CLKD1             0x0028
> +#define SPRD_CLKD1_MASK                GENMASK(20, 16)
> +#define SPRD_CLKD1_SHIFT       16
>
>  /* interrupt mask status register */
>  #define SPRD_IMSR                      0x002C
> @@ -115,7 +121,7 @@ static inline void serial_out(struct uart_port *port, int offset, int value)
>
>  static unsigned int sprd_tx_empty(struct uart_port *port)
>  {
> -       if (serial_in(port, SPRD_STS1) & 0xff00)
> +       if (serial_in(port, SPRD_STS1) & SPRD_TX_FIFO_CNT_MASK)
>                 return 0;
>         else
>                 return TIOCSER_TEMT;
> @@ -213,7 +219,8 @@ static inline void sprd_rx(struct uart_port *port)
>         struct tty_port *tty = &port->state->port;
>         unsigned int ch, flag, lsr, max_count = SPRD_TIMEOUT;
>
> -       while ((serial_in(port, SPRD_STS1) & 0x00ff) && max_count--) {
> +       while ((serial_in(port, SPRD_STS1) & SPRD_RX_FIFO_CNT_MASK) &&
> +              max_count--) {
>                 lsr = serial_in(port, SPRD_LSR);
>                 ch = serial_in(port, SPRD_RXD);
>                 flag = TTY_NORMAL;
> @@ -303,16 +310,17 @@ static int sprd_startup(struct uart_port *port)
>         struct sprd_uart_port *sp;
>         unsigned long flags;
>
> -       serial_out(port, SPRD_CTL2, ((THLD_TX_EMPTY << 8) | THLD_RX_FULL));
> +       serial_out(port, SPRD_CTL2,
> +                  THLD_TX_EMPTY << THLD_TX_EMPTY_SHIFT | THLD_RX_FULL);
>
>         /* clear rx fifo */
>         timeout = SPRD_TIMEOUT;
> -       while (timeout-- && serial_in(port, SPRD_STS1) & 0x00ff)
> +       while (timeout-- && serial_in(port, SPRD_STS1) & SPRD_RX_FIFO_CNT_MASK)
>                 serial_in(port, SPRD_RXD);
>
>         /* clear tx fifo */
>         timeout = SPRD_TIMEOUT;
> -       while (timeout-- && serial_in(port, SPRD_STS1) & 0xff00)
> +       while (timeout-- && serial_in(port, SPRD_STS1) & SPRD_TX_FIFO_CNT_MASK)
>                 cpu_relax();
>
>         /* clear interrupt */
> @@ -433,10 +441,11 @@ static void sprd_set_termios(struct uart_port *port,
>         }
>
>         /* clock divider bit0~bit15 */
> -       serial_out(port, SPRD_CLKD0, quot & 0xffff);
> +       serial_out(port, SPRD_CLKD0, quot & SPRD_CLKD0_MASK);
>
>         /* clock divider bit16~bit20 */
> -       serial_out(port, SPRD_CLKD1, (quot & 0x1f0000) >> 16);
> +       serial_out(port, SPRD_CLKD1,
> +                  (quot & SPRD_CLKD1_MASK) >> SPRD_CLKD1_SHIFT);
>         serial_out(port, SPRD_LCR, lcr);
>         fc |= RX_TOUT_THLD_DEF | RX_HFC_THLD_DEF;
>         serial_out(port, SPRD_CTL1, fc);
> @@ -510,7 +519,7 @@ static void wait_for_xmitr(struct uart_port *port)
>                 if (--tmout == 0)
>                         break;
>                 udelay(1);
> -       } while (status & 0xff00);
> +       } while (status & SPRD_TX_FIFO_CNT_MASK);
>  }
>
>  static void sprd_console_putchar(struct uart_port *port, int ch)
> --
> 1.9.1
>