On Thu, 7 Apr 2022 at 12:45, Lai Jason <jasonlai.genesyslogic@xxxxxxxxx> wrote: > > Hi Uffe, > > On Thu, Mar 24, 2022 at 12:16 AM Ulf Hansson <ulf.hansson@xxxxxxxxxx> wrote: > > > > On Tue, 22 Feb 2022 at 04:40, 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[3]. > > > > > > [3] > > > 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 | 835 ++++++++++++++++++++++++++++++++++++- > > > 1 file changed, 817 insertions(+), 18 deletions(-) > > > > > > diff --git a/drivers/mmc/core/sd_uhs2.c b/drivers/mmc/core/sd_uhs2.c > > > index 800957f74632..f1e8e30301eb 100644 > > > --- a/drivers/mmc/core/sd_uhs2.c > > > +++ b/drivers/mmc/core/sd_uhs2.c > > > @@ -3,6 +3,7 @@ > > > * Copyright (C) 2021 Linaro Ltd > > > * > > > * Author: Ulf Hansson <ulf.hansson@xxxxxxxxxx> > > > + * Author: Jason Lai <jason.lai@xxxxxxxxxxxxxxxxxxx> > > > * > > > * Support for SD UHS-II cards > > > */ > > > @@ -10,19 +11,31 @@ > > > > > > #include <linux/mmc/host.h> > > > #include <linux/mmc/card.h> > > > +#include <linux/mmc/mmc.h> > > > +#include <linux/mmc/sd_uhs2.h> > > > > > > #include "core.h" > > > #include "bus.h" > > > +#include "card.h" > > > #include "sd.h" > > > +#include "sd_ops.h" > > > #include "mmc_ops.h" > > > +#include "sd_uhs2.h" > > > > > > static const unsigned int sd_uhs2_freqs[] = { 52000000, 26000000 }; > > > > > > static int sd_uhs2_set_ios(struct mmc_host *host) > > > { > > > struct mmc_ios *ios = &host->ios; > > > + int err = 0; > > > > > > - return host->ops->uhs2_set_ios(host, ios); > > > + pr_debug("%s: clock %uHz powermode %u Vdd %u timing %u\n", > > > + mmc_hostname(host), ios->clock, ios->power_mode, ios->vdd, > > > + ios->timing); > > > + > > > + host->ops->set_ios(host, ios); > > > > We discussed using the ->set_ios() callback in a previous version. To > > repeat myself, I don't think it's a good idea. UHS-II needs an > > entirely different power sequence than the legacy interface(s), hence > > I think it's simply cleaner to separate them. > > > > To move forward, I see two options. > > 1) Use only the ->uhs2_host_operation() ops. > > 2) Use a combination of the ->uhs2_set_ios() ops and the > > ->uhs2_host_operation() ops. > > > > I referred to the usage of "host->ops->set_ios" in core.c, it is called in > mmc_set_ios() and ".set_ios" is directed to sdhci_set_ios(), which is > located in mmc/host/sdhci.c. So I created sd_uhs2_set_ios() and call > host->ops->uhs2_set_ios() inside it. The ".uhs2_set_ios" is left to host > part to implement it. I see. In that case, what you are looking for is an sdhci specific callback, this wouldn't belong as part of the generic mmc host ops. That said, I still think we need to choose between the two options I suggested above. Otherwise, I fear that it will turn into a nightmare for the mmc host drivers to support both UHS-II and the legacy interface. In other words, I strongly suggest that we must not call ->set_ios() to manage the UHS-II interface. > > > Both options work for me. However, perhaps if you could incorporate > > the changes done on the host driver at next submission, it becomes > > easier for me to understand what makes best sense. > > > > > + > > > + return err; > > > } > > > [...] > > > static int sd_uhs2_config_write(struct mmc_host *host, struct mmc_card *card) > > > { > > > + struct mmc_command cmd = {0}; > > > + struct uhs2_command uhs2_cmd = {}; > > > + u16 header = 0, arg = 0; > > > + u32 payload[2]; > > > + u8 nMinDataGap; > > > + u8 plen; > > > + int err; > > > + u8 resp[5] = {0}; > > > + u8 resp_len = 5; > > > + > > > + header = UHS2_NATIVE_PACKET | > > > + UHS2_PACKET_TYPE_CCMD | card->uhs2_config.node_id; > > > + arg = ((UHS2_DEV_CONFIG_GEN_SET & 0xFF) << 8) | > > > + UHS2_NATIVE_CMD_WRITE | > > > + UHS2_NATIVE_CMD_PLEN_8B | > > > + (UHS2_DEV_CONFIG_GEN_SET >> 8); > > > + > > > + if (card->uhs2_config.n_lanes == UHS2_DEV_CONFIG_2L_HD_FD && > > > + host->uhs2_caps.n_lanes == UHS2_DEV_CONFIG_2L_HD_FD) { > > > + /* Support HD */ > > > + host->uhs2_caps.flags |= MMC_UHS2_2L_HD; > > > > How is the uhs2_caps.flags field intended to be used? To me it looks > > like a way for the mmc core to exchange status/configuration > > information about the initialization process of the card, with the mmc > > host driver. Perhaps there is more too. Is that correct? > > > > If so, I think it looks quite similar for what we have in the struct > > mmc_ios, for the legacy interface(s). I am not saying we should use > > that, just trying to understand what would suit best here. > > > > The usage of uhs2_caps.flags is spread out through core and host. > All operations related to it cannot be integrated into uhs2_set_ios() > simply. I recommend maintaining the status quo. What is puzzling to me, is that the data is stored below uhs2_caps.* and that it's called "flags". It's not self-explanatory and it's not consistent with the way we use the ->set_ios() callback, for the legacy interface. It looks to me that we should rather add a new variable to the struct mmc_host and perhaps name it "uhs2_ios", to keep this data. Whether we need to create a new struct for "uhs2_ios" or if it's better to extend struct mmc_ios, I am not sure. I guess exploring this by writing the code would tell us what is best suited. > > > > + nMinDataGap = 1; > > > + } else { > > > + /* Only support 2L-FD so far */ > > > + host->uhs2_caps.flags &= ~MMC_UHS2_2L_HD; > > > + nMinDataGap = 3; > > > + } > > > + > > > + /* > > > + * Most UHS-II cards only support FD and 2L-HD mode. Other lane numbers > > > + * defined in UHS-II addendem Ver1.01 are optional. > > > + */ > > > + host->uhs2_caps.n_lanes_set = UHS2_DEV_CONFIG_GEN_SET_2L_FD_HD; > > > + card->uhs2_config.n_lanes_set = UHS2_DEV_CONFIG_GEN_SET_2L_FD_HD; > > > > [...] > > > > > +static int sd_uhs2_go_dormant(struct mmc_host *host, bool hibernate, u32 node_id) > > > +{ > > > > Looks like the in-parameter "hibernate" is superfluous, as it's always > > set to "false" by the caller. > > > > The in-parameter "hibernate" is designed according to UHS-II > specification. We did not use > it for now. But we are not sure if it will be set to true in future > use. So I suggest keeping it. I understand your point, but I don't agree, sorry. We don't want dead code around in the kernel, so please remove it. Perhaps what we can do, is to add a comment in sd_uhs2_go_dormant(), somewhere we default to not use hibernate, we could simply explain that hibernation is currently not supported. > > > > + struct mmc_command cmd = {0}; > > > + struct uhs2_command uhs2_cmd = {}; > > > + u16 header = 0, arg = 0; > > > + u32 payload[1]; > > > + u8 plen = 1; > > > + int err; > > > + > > > + /* Disable Normal INT */ > > > + if (!host->ops->uhs2_host_operation(host, UHS2_DISABLE_INT)) { > > > + pr_err("%s: %s: UHS2 DISABLE_INT fail!\n", > > > + mmc_hostname(host), __func__); > > > + return -EIO; > > > + } > > > + > > > + header = UHS2_NATIVE_PACKET | UHS2_PACKET_TYPE_CCMD | node_id; > > > + > > > + arg = ((UHS2_DEV_CMD_GO_DORMANT_STATE & 0xFF) << 8) | > > > + UHS2_NATIVE_CMD_WRITE | > > > + UHS2_NATIVE_CMD_PLEN_4B | > > > + (UHS2_DEV_CMD_GO_DORMANT_STATE >> 8); > > > + > > > + if (hibernate) > > > + payload[0] = UHS2_DEV_CMD_DORMANT_HIBER; > > > + > > > + sd_uhs2_cmd_assemble(&cmd, &uhs2_cmd, header, arg, payload, plen, NULL, 0); > > > + > > > + err = mmc_wait_for_cmd(host, &cmd, 0); > > > + if (err) { > > > + pr_err("%s: %s: UHS2 CMD send fail, err= 0x%x!\n", > > > + mmc_hostname(host), __func__, err); > > > + return -EIO; > > > + } > > > + > > > + /* Check Dormant State in Present */ > > > + if (!host->ops->uhs2_host_operation(host, UHS2_CHECK_DORMANT)) { > > > + pr_err("%s: %s: UHS2 GO_DORMANT_STATE fail!\n", > > > + mmc_hostname(host), __func__); > > > + return -EIO; > > > + } > > > + > > > + host->ops->uhs2_host_operation(host, UHS2_DISABLE_CLK); > > > + > > > return 0; > > > } [...] Kind regards Uffe
