Re: [PATCHv2 0/4] ACPI / LPSS: Solution for two issues seen on Asus T100

["Li, Aubrey" <aubrey.li@linux.intel.com>]

On 2014/5/15 21:40, Heikki Krogerus wrote:
> Changes since v1:
> - now using do_div() in clk_fd_recalc_rate() as suggested by Andy
> - NULL checks for clk_name allocation in acpi_lpss.c
> 
> This combines two patch sets for LPSS that I had already send for
> review separately. They conflicted with each other.
> 
> The first two patches will fix a problem were the context of the
> private LPSS registers is lost when entering D3. The last two will add
> support for the M/N dividers on LPSS by adding a new basic clock type
> for fractional dividers. The UART driver needs support for it in order
> to get clock rates that suit the requested baud rates.

The major issue in my mind is, this proposal makes a couple between I2C
designware, HSUART, or probably DMA driver as well with LPSS driver.
That is, currently without LPSS driver, I2C/HSUART won't work properly.
So we at least need to describe this dependency in Kconfig.

Thanks,
-Aubrey
> 
> 
> Heikki Krogerus (4):
>   ACPI / PM: Export rest of the subsys functions
>   ACPI / LPSS: custom power domain for LPSS
>   clk: new basic clk type for fractional divider
>   ACPI / LPSS: support for fractional divider clock
> 
>  drivers/acpi/acpi_lpss.c             | 204 ++++++++++++++++++++++++++++++-----
>  drivers/acpi/device_pm.c             |   2 +
>  drivers/clk/Makefile                 |   1 +
>  drivers/clk/clk-fractional-divider.c | 135 +++++++++++++++++++++++
>  include/linux/acpi.h                 |   4 +
>  include/linux/clk-provider.h         |  31 ++++++
>  6 files changed, 349 insertions(+), 28 deletions(-)
>  create mode 100644 drivers/clk/clk-fractional-divider.c
>