On Wed, Dec 15, 2021 at 4:29 AM Ulf Hansson <ulf.hansson@xxxxxxxxxx> wrote: > > On Fri, 3 Dec 2021 at 11:51, Jason Lai <jasonlai.genesyslogic@xxxxxxxxx> wrote: > > > > From: Jason Lai <jason.lai@xxxxxxxxxxxxxxxxxxx> > > > > UHS-II card initialization flow is divided into 2 categories: PHY & Card. > > Part 1 - PHY Initialization: > > Every host controller may need their own avtivation operation > > to establish LINK between controller and card. So we add a new > > member function(uhs2_detect_init) in struct mmc_host_ops for host > > controller use. > > Part 2 - Card Initialization: > > This part can be divided into 6 substeps. > > 1. Send UHS-II CCMD DEVICE_INIT to card. > > 2. Send UHS-II CCMD ENUMERATE to card. > > 3. Send UHS-II Native Read CCMD to obtain capabilities in CFG_REG > > of card. > > 4. Host compares capabilities of host controller and card, > > then write the negotiated values to Setting field in CFG_REG > > of card through UHS-II Native Write CCMD. > > 5. Switch host controller's clock to Range B if it is supported > > by both host controller and card. > > 6. Execute legacy SD initialization flow. > > Part 3 - Provide a function to tranaform legacy SD command packet into > > UHS-II SD-TRAN DCMD packet. > > > > Most of the code added above came from Intel's original patch[1]. > > > > [1] > > https://patchwork.kernel.org/project/linux-mmc/patch/1419672479-30852-2- > > git-send-email-yi.y.sun@xxxxxxxxx/ > > > > Signed-off-by: Jason Lai <jason.lai@xxxxxxxxxxxxxxxxxxx> > > --- > > drivers/mmc/core/sd_uhs2.c | 831 ++++++++++++++++++++++++++++++++++++- > > 1 file changed, 810 insertions(+), 21 deletions(-) > > > > diff --git a/drivers/mmc/core/sd_uhs2.c b/drivers/mmc/core/sd_uhs2.c > > index 24aa51a6d..d13283d54 100644 > > --- a/drivers/mmc/core/sd_uhs2.c > > +++ b/drivers/mmc/core/sd_uhs2.c > > @@ -3,6 +3,7 @@ [...] > > +/** > > + * sd_uhs2_cmd_assemble() - build up UHS-II command packet which is embeded in > > + * mmc_command structure > > + * @cmd: MMC command to executed > > + * @uhs2_cmd: UHS2 command corresponded to MMC command > > + * @header: Header field of UHS-II command cxpacket > > + * @arg: Argument field of UHS-II command packet > > + * @payload: Payload field of UHS-II command packet > > + * @plen: Payload length > > + * @resp: Response buffer is allocated by caller and it is used to keep > > + * the response of CM-TRAN command. For SD-TRAN command, uhs2_resp > > + * should be null and SD-TRAN command response should be stored in > > + * resp of mmc_command. > > + * @resp_len: Response buffer length > > + * > > + * Different from legacy SD command, there defined several types of packets > > + * in UHS-II, which include CM-TRAN and SD-TRAN. These packets are then > > + * transformed to differential signals and transmitted/received between > > + * transceiver and receiver. > > + * > > + * The UHS-II packet structure(uhs2_cmd) are added in structure mmc_command > > + * and be filled according to the inputed parameters provided by caller. > > + * > > + * For mmc requests, call this function before issuing command to SD card. > > + * Host controller specific request function will send packet in uhs2_cmd > > + * to UHS-II SD card. > > + * > > I think we discussed the above functions description earlier. The > above description is just way too overwhelming. What the function does > is that fills out the uhs2_cmd data structure, that's it. > > As this is a static function, I wouldn't mind that you simply drop the > entire function description above. Or try to make the description > short and clear. I try to make the function description more briefly: /** * sd_uhs2_cmd_assemble() - build up UHS-II command packet which is embeded in * mmc_command structure * @cmd: MMC command to executed * @uhs2_cmd: UHS2 command corresponded to MMC command * @header: Header field of UHS-II command cxpacket * @arg: Argument field of UHS-II command packet * @payload: Payload field of UHS-II command packet * @plen: Payload length * @resp: Response buffer is allocated by caller and it is used to keep * the response of CM-TRAN command. For SD-TRAN command, uhs2_resp * should be null and SD-TRAN command response should be stored in * resp of mmc_command. * @resp_len: Response buffer length * * The uhs2_command structure contains message packets which are transmited/ * received on UHS-II bus. This function fills in the contents of uhs2_command * structure and embededs UHS2 command into mmc_command structure, which is used * in legacy SD operation functions. * */ What do you think? kind regards, Jason Lai > [...] > > I have stopped the review at this point, let's see if we can conclude > on the way forward around my comments on the parts above, to start > with. > > Kind regards > Uffe
