[U-Boot] [PATCH u-boot 3/5] aspeed: Added function to calculate APB Clock frequency.

[Simon Glass]

[resend from correct address]

On 23 November 2016 at 09:13, Simon Glass <sjg at google.com> wrote:
> Hi Maxim,
>
> On 22 November 2016 at 16:56,  <maxims at google.com> wrote:
>> From: Maxim Sloyko <maxims at google.com>
>>
>
> For the subject, 'Add' rather than 'Added' (we use present tense)
>
>> This is needed by I2C driver.
>>
>> Signed-off-by: Maxim Sloyko <maxims at google.com>
>> ---
>>  arch/arm/include/asm/arch-aspeed/ast_scu.h |  1 +
>>  arch/arm/mach-aspeed/ast-scu.c             | 11 +++++++++++
>>  2 files changed, 12 insertions(+)
>>
>> diff --git a/arch/arm/include/asm/arch-aspeed/ast_scu.h b/arch/arm/include/asm/arch-aspeed/ast_scu.h
>> index d248416..eb5aaa2 100644
>> --- a/arch/arm/include/asm/arch-aspeed/ast_scu.h
>> +++ b/arch/arm/include/asm/arch-aspeed/ast_scu.h
>> @@ -38,6 +38,7 @@ extern void ast_scu_get_who_init_dram(void);
>>  extern u32 ast_get_clk_source(void);
>>  extern u32 ast_get_h_pll_clk(void);
>>  extern u32 ast_get_ahbclk(void);
>> +extern u32 ast_get_apbclk(void);
>
> Please add a comment as to what this does and what it returns.
>
>>
>>  extern u32 ast_scu_get_vga_memsize(void);
>>
>> diff --git a/arch/arm/mach-aspeed/ast-scu.c b/arch/arm/mach-aspeed/ast-scu.c
>> index 280c421..e00dbe2 100644
>> --- a/arch/arm/mach-aspeed/ast-scu.c
>> +++ b/arch/arm/mach-aspeed/ast-scu.c
>> @@ -318,6 +318,17 @@ u32 ast_get_ahbclk(void)
>>
>>  #endif /* AST_SOC_G5 */
>>
>> +u32 ast_get_apbclk(void)
>> +{
>> +       u32 h_pll = ast_get_h_pll_clk();
>
> Can this be ulong, or is there a reason it has to be exactly 32 bits?
>
> blank line here (between declarations and code)
>
>> +       /* The formula for converting the bit pattern to divisor is
>
> /*
>  * The formula...
>  * ...
>  */
>
>> +        * (4 + 4 * DIV), according to datasheet
>> +        */
>> +       u32 apb_div = 4 + 4 * SCU_GET_PCLK_DIV(ast_scu_read(AST_SCU_CLK_SEL));
>> +       return h_pll / apb_div;
>> +}
>> +
>> +
>>  void ast_scu_show_system_info(void)
>>  {
>>
>> --
>> 2.8.0.rc3.226.g39d4020
>>
>
> Regards,
> Simon