[PATCH v3 04/18] i.MX: serial: Add UART init functions for DEBUG_LL

[Sascha Hauer]

On Wed, May 06, 2015 at 12:31:59PM -0700, Andrey Smirnov wrote:
> It appears that all i.MX51 and i.MX6 based boards that support early
> debug output inevitably do exactly the same thing with the registers
> of the UART peripheral. So to avoid code duplication three new
> subroutines are introduced:
> 
>   - imx_uart_setup_ll() that allows user to perform aforementioned
>     "same thing" on any arbitrary UART at 'uartbase' and clocked at
>     'refclock' Hz.
> 
>   - imx6_uart_setup_ll() and imx5_uart_setup_ll() that do those
>     actions assuming UART to be the one specified in configuration and
>     'refclock' to be equal to what it is when SoC comes out of reset.
> 
> NOTE: Please note that 'imx*_uart_setup_ll' functions do add a slight
> difference in behaviour by dropping the initialization of ONEMS and
> UESC registers since those do not seem to be needed for early UART
> functionality
> 
> Signed-off-by: Andrey Smirnov <andrew.smirnov at gmail.com>
> ---
>  arch/arm/mach-imx/include/mach/debug_ll.h | 55 +++++++++++++++++++++++++++++--
>  1 file changed, 53 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm/mach-imx/include/mach/debug_ll.h b/arch/arm/mach-imx/include/mach/debug_ll.h
> index 31371e2..baf7f53 100644
> --- a/arch/arm/mach-imx/include/mach/debug_ll.h
> +++ b/arch/arm/mach-imx/include/mach/debug_ll.h
> @@ -3,6 +3,7 @@
>  
>  #include <io.h>
>  #include <config.h>
> +#include <common.h>
>  #include <mach/imx1-regs.h>
>  #include <mach/imx21-regs.h>
>  #include <mach/imx25-regs.h>
> @@ -17,6 +18,36 @@
>  
>  #ifdef CONFIG_DEBUG_LL
>  
> +#define __IMX_UART_BASE(soc, num) soc##_UART##num##_BASE_ADDR
> +#define IMX_UART_BASE(soc, num) __IMX_UART_BASE(soc, num)
> +
> +static inline void imx_uart_setup_ll(void __iomem *uartbase,
> +				     unsigned int refclock)
> +{
> +	writel(0x00000000, uartbase + UCR1);
> +
> +	writel(UCR2_IRTS | UCR2_WS | UCR2_TXEN | UCR2_RXEN | UCR2_SRST,
> +	       uartbase + UCR2);
> +	writel(UCR3_DSR | UCR3_DCD | UCR3_RI | UCR3_ADNIMP | UCR3_RXDMUXSEL,
> +	       uartbase + UCR3);
> +	writel((0b10 << UFCR_TXTL_SHF) | UFCR_RFDIV1 | (1 << UFCR_RXTL_SHF),
> +	       uartbase + UFCR);
> +
> +	writel(baudrate_to_ubir(CONFIG_BAUDRATE),
> +	       uartbase + UBIR);
> +	writel(refclock_to_ubmr(refclock),
> +	       uartbase + UBMR);
> +
> +	writel(UCR1_UARTEN, uartbase + UCR1);
> +}
> +
> +#define __imx_uart_setup_ll(refclock)					\
> +	do {								\
> +		imx_uart_setup_ll(IOMEM(IMX_UART_BASE(IMX_DEBUG_SOC,	\
> +						      CONFIG_DEBUG_IMX_UART_PORT)), \
> +				  refclock);				\
> +	} while(0)
> +
>  #ifdef CONFIG_DEBUG_IMX1_UART
>  #define IMX_DEBUG_SOC MX1
>  #elif defined CONFIG_DEBUG_IMX21_UART
> @@ -39,8 +70,19 @@
>  #error "unknown i.MX debug uart soc type"
>  #endif
>  
> -#define __IMX_UART_BASE(soc, num) soc##_UART##num##_BASE_ADDR
> -#define IMX_UART_BASE(soc, num) __IMX_UART_BASE(soc, num)
> +static inline void imx51_uart_setup_ll(void)
> +{
> +#if defined CONFIG_DEBUG_IMX51_UART
> +	__imx_uart_setup_ll(54000000);
> +#endif
> +}
> +
> +static inline void imx6_uart_setup_ll(void)
> +{
> +#if defined CONFIG_DEBUG_IMX6Q_UART
> +	__imx_uart_setup(80000000);
> +#endif

Typo here, should be __imx_uart_setup_ll like above. I also removed the
#ifdefs which seem unnecessary.

Sascha

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