Re: [PATCH v3 22/23] ata: ahci-dwc: Add Baikal-T1 AHCI SATA interface support

Hannes Reinecke
2022-05-12T07:13:58Z

On 5/12/22 01:18, Serge Semin wrote:
> It's almost fully compatible DWC AHCI SATA IP-core derivative except the
> reference clocks source, which need to be very carefully selected. In
> particular the DWC AHCI SATA PHY can be clocked either from the pads
> ref_pad_clk_{m,p} or from the internal wires ref_alt_clk_{m,n}. In the
> later case the clock signal is generated from the Baikal-T1 CCU SATA PLL.
> The clocks source is selected by means of the ref_use_pad wire connected
> to the CCU SATA reference clock CSR.
>
> In normal situation it would be much more handy to use the internal
> reference clock source, but alas we haven't managed to make the AHCI
> controller working well with it so far. So it's preferable to have the
> controller clocked from the external clock generator and fallback to the
> internal clock source only as a last resort. Other than that the
> controller is full compatible with the DWC AHCI SATA IP-core.
>
> Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
>
> ---
>
> Changelog v2:
> - Rename 'syscon' property to 'baikal,bt1-syscon'.
> - Change the local objects prefix from 'dwc_ahci_' to 'ahci_dwc_',
> from 'bt1_ahci_' to 'ahci_bt1_'. (@Damien)
> ---
> drivers/ata/Kconfig | 1 +
> drivers/ata/ahci_dwc.c | 87 ++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 88 insertions(+)
>
Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes

--
Dr. Hannes Reinecke Kernel Storage Architect
hare@suse.de +49 911 74053 688
SUSE Software Solutions Germany GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), GF: Felix Imendörffer