[PATCH v6 12/16] OMAP2+: UART: Allow UART parameters to be configured from board file.

[Govindraj]

On Wed, Oct 12, 2011 at 12:23 AM, Kevin Hilman <khilman at ti.com> wrote:
> "Govindraj.R" <govindraj.raja at ti.com> writes:
>
>> From: Deepak K <deepak.k at ti.com>
>>
>> The following UART parameters are defined within the UART driver:
>>
>> 1). Whether the UART uses DMA (dma_enabled), by default set to 0
>> 2). The size of dma buffer (set to 4096 bytes)
>> 3). The time after which the dma should stop if no more data is received.
>> 4). The auto suspend delay that will be passed for pm_runtime_autosuspend
>>     where uart will be disabled after timeout
>>
>> Different UARTs may be used for different purpose such as the console,
>> for interfacing bluetooth chip, for interfacing to a modem chip, etc.
>> Therefore, it is necessary to be able to customize the above settings
>> for a given board on a per UART basis.
>>
>> This change allows these parameters to be configured from the board file
>> and allows the parameters to be configured for each UART independently.
>>
>> If a board does not define its own custom parameters for the UARTs, then
>> use the default parameters in the structure "omap_serial_default_info".
>> The default parameters are defined to be the same as the current settings
>> in the UART driver to avoid breaking the UART for any cuurnelty supported
>> boards. By default, make all boards use the default UART parameters.
>>
>> Signed-off-by: Deepak K <deepak.k at ti.com>
>> Signed-off-by: Jon Hunter <jon-hunter at ti.com>
>> Signed-off-by: Govindraj.R <govindraj.raja at ti.com>
>
> A couple minor comments below...
>
>> ---
>> This patch is derived and reworked from a custom 2.6.35 kernel
>> Available here:
>> http://git.omapzoom.org/?p=kernel/omap.git;
>> a=commitdiff;h=584ef316542f77312be7ba96a0f3013c8f64852b;
>> hp=7233a76cb362c0fc603f773274159adff91d3513
>>
>>  arch/arm/mach-omap2/board-n8x0.c              |    6 +-
>>  arch/arm/mach-omap2/serial.c                  |   56 ++++++++++++++++++++----
>>  arch/arm/plat-omap/include/plat/omap-serial.h |    7 ++-
>>  arch/arm/plat-omap/include/plat/serial.h      |    5 ++-
>>  drivers/tty/serial/omap-serial.c              |    8 +--
>>  5 files changed, 61 insertions(+), 21 deletions(-)
>>
>> diff --git a/arch/arm/mach-omap2/board-n8x0.c b/arch/arm/mach-omap2/board-n8x0.c
>> index e11f0c5..3408726 100644
>> --- a/arch/arm/mach-omap2/board-n8x0.c
>> +++ b/arch/arm/mach-omap2/board-n8x0.c
>> @@ -656,15 +656,15 @@ static inline void board_serial_init(void)
>>       bdata.pads_cnt = 0;
>>
>>       bdata.id = 0;
>> -     omap_serial_init_port(&bdata);
>> +     omap_serial_init_port(&bdata, NULL);
>>
>>       bdata.id = 1;
>> -     omap_serial_init_port(&bdata);
>> +     omap_serial_init_port(&bdata, NULL);
>>
>>       bdata.id = 2;
>>       bdata.pads = serial2_pads;
>>       bdata.pads_cnt = ARRAY_SIZE(serial2_pads);
>> -     omap_serial_init_port(&bdata);
>> +     omap_serial_init_port(&bdata, NULL);
>>  }
>>
>>  #else
>> diff --git a/arch/arm/mach-omap2/serial.c b/arch/arm/mach-omap2/serial.c
>> index 0731575..78f7051 100644
>> --- a/arch/arm/mach-omap2/serial.c
>> +++ b/arch/arm/mach-omap2/serial.c
>> @@ -43,17 +43,29 @@
>>  #include "mux.h"
>>
>>  /*
>> - * NOTE: By default the serial timeout is disabled as it causes lost characters
>> - * over the serial ports. This means that the UART clocks will stay on until
>> - * disabled via sysfs. This also causes that any deeper omap sleep states are
>> - * blocked.
>> + * NOTE: By default the serial auto_suspend timeout is disabled as it causes
>> + * lost characters over the serial ports. This means that the UART clocks will
>> + * stay on until power/autosuspend_delay is set for the uart from sysfs.
>> + * This also causes that any deeper omap sleep states are blocked.
>>   */
>> -#define DEFAULT_TIMEOUT 0
>> +#define DEFAULT_AUTOSUSPEND_DELAY    -1
>>
>>  #define MAX_UART_HWMOD_NAME_LEN              16
>>
>>  static u8 num_uarts;
>>
>> +#define DEFAULT_RXDMA_TIMEOUT                1       /* RX DMA polling rate (us) */
>> +#define DEFAULT_RXDMA_BUFSIZE                4096    /* RX DMA buffer size */
>> +
>> +static struct omap_uart_port_info omap_serial_default_info[] = {
>
> This could be __initdata
>

yes correct, will change this.


>> +     {
>> +             .dma_enabled    = 0,
>
> This field is a bool, use 'false' instead of 0.

yes fine.

>
>> +             .dma_rx_buf_size = DEFAULT_RXDMA_BUFSIZE,
>> +             .dma_rx_timeout = DEFAULT_RXDMA_TIMEOUT,
>> +             .autosuspend_timeout = DEFAULT_AUTOSUSPEND_DELAY,
>> +     },
>> +};
>> +
>>  static int uart_idle_hwmod(struct omap_device *od)
>>  {
>>       omap_hwmod_idle(od->hwmods[0]);
>> @@ -298,6 +310,7 @@ core_initcall(omap_serial_early_init);
>>  /**
>>   * omap_serial_init_port() - initialize single serial port
>>   * @bdata: port specific board data pointer
>> + * @info: platform specific data pointer
>>   *
>>   * This function initialies serial driver for given port only.
>>   * Platforms can call this function instead of omap_serial_init()
>> @@ -306,7 +319,8 @@ core_initcall(omap_serial_early_init);
>>   * Don't mix calls to omap_serial_init_port() and omap_serial_init(),
>>   * use only one of the two.
>>   */
>> -void __init omap_serial_init_port(struct omap_board_data *bdata)
>> +void __init omap_serial_init_port(struct omap_board_data *bdata,
>> +                     struct omap_uart_port_info *info)
>
> alignment.  2nd argument should align with 1st
>
>>  {
>>       struct omap_hwmod *oh;
>>       struct platform_device *pdev;
>> @@ -325,6 +339,9 @@ void __init omap_serial_init_port(struct omap_board_data *bdata)
>>       if (!oh)
>>               return;
>>
>> +     if (info == NULL)
>
> if (!info)
>
> there's another one of these elsewhere in the patch too.
>

will check and correct.

--
Thanks,
Govindraj.R