mmc: rtsx_pci: Add SD Express mode support for RTS5261

RTS5261 support SD mode and PCIe/NVMe mode. The workflow is as follows.
1.RTS5261 work in SD mode and set MMC_CAPS2_SD_EXP flag.
2.If card is plugged in, Host send CMD8 to ask card's PCIe availability.
3.If the card has PCIe availability and WP is not set, init_sd_express() will be invoked,
RTS5261 switch to PCIe/NVMe mode.
4.Mmc driver handover it to NVMe driver.
5.If card is unplugged, RTS5261 will switch to SD mode.

Signed-off-by: Rui Feng <rui_feng@realsil.com.cn>
Link: https://lore.kernel.org/r/1603936703-3403-1-git-send-email-rui_feng@realsil.com.cn
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/mmc/host/rtsx_pci_sdmmc.c b/drivers/mmc/host/rtsx_pci_sdmmc.c
index eb395e1..c584070 100644 (file)
--- a/drivers/mmc/host/rtsx_pci_sdmmc.c
+++ b/drivers/mmc/host/rtsx_pci_sdmmc.c
@@ -895,7 +895,9 @@ static int sd_set_bus_width(struct realtek_pci_sdmmc *host,
 static int sd_power_on(struct realtek_pci_sdmmc *host)
 {
        struct rtsx_pcr *pcr = host->pcr;
+       struct mmc_host *mmc = host->mmc;
        int err;
+       u32 val;
 
        if (host->power_state == SDMMC_POWER_ON)
                return 0;
@@ -922,6 +924,21 @@ static int sd_power_on(struct realtek_pci_sdmmc *host)
        if (err < 0)
                return err;
 
+       if (PCI_PID(pcr) == PID_5261) {
+               if (pcr->extra_caps & EXTRA_CAPS_SD_EXPRESS)
+                       mmc->caps2 |= MMC_CAP2_SD_EXP | MMC_CAP2_SD_EXP_1_2V;
+               /*
+                * HW read wp status when resuming from S3/S4,
+                * and then picks SD legacy interface if it's set
+                * in read-only mode.
+                */
+               val = rtsx_pci_readl(pcr, RTSX_BIPR);
+               if (val & SD_WRITE_PROTECT) {
+                       pcr->extra_caps &= ~EXTRA_CAPS_SD_EXPRESS;
+                       mmc->caps2 &= ~(MMC_CAP2_SD_EXP | MMC_CAP2_SD_EXP_1_2V);
+               }
+       }
+
        host->power_state = SDMMC_POWER_ON;
        return 0;
 }
@@ -1308,6 +1325,44 @@ out:
        return err;
 }
 
+static int sdmmc_init_sd_express(struct mmc_host *mmc, struct mmc_ios *ios)
+{
+       u32 relink_time;
+       struct realtek_pci_sdmmc *host = mmc_priv(mmc);
+       struct rtsx_pcr *pcr = host->pcr;
+
+       /* Set relink_time for changing to PCIe card */
+       relink_time = 0x8FFF;
+
+       rtsx_pci_write_register(pcr, 0xFF01, 0xFF, relink_time);
+       rtsx_pci_write_register(pcr, 0xFF02, 0xFF, relink_time >> 8);
+       rtsx_pci_write_register(pcr, 0xFF03, 0x01, relink_time >> 16);
+
+       rtsx_pci_write_register(pcr, PETXCFG, 0x80, 0x80);
+       rtsx_pci_write_register(pcr, LDO_VCC_CFG0,
+               RTS5261_LDO1_OCP_THD_MASK,
+               pcr->option.sd_800mA_ocp_thd);
+
+       if (pcr->ops->disable_auto_blink)
+               pcr->ops->disable_auto_blink(pcr);
+
+       /* For PCIe/NVMe mode can't enter delink issue */
+       pcr->hw_param.interrupt_en &= ~(SD_INT_EN);
+       rtsx_pci_writel(pcr, RTSX_BIER, pcr->hw_param.interrupt_en);
+
+       rtsx_pci_write_register(pcr, RTS5260_AUTOLOAD_CFG4,
+               RTS5261_AUX_CLK_16M_EN, RTS5261_AUX_CLK_16M_EN);
+       rtsx_pci_write_register(pcr, RTS5261_FW_CFG0,
+               RTS5261_FW_ENTER_EXPRESS, RTS5261_FW_ENTER_EXPRESS);
+       rtsx_pci_write_register(pcr, RTS5261_FW_CFG1,
+               RTS5261_MCU_BUS_SEL_MASK | RTS5261_MCU_CLOCK_SEL_MASK
+               | RTS5261_MCU_CLOCK_GATING | RTS5261_DRIVER_ENABLE_FW,
+               RTS5261_MCU_CLOCK_SEL_16M | RTS5261_MCU_CLOCK_GATING
+               | RTS5261_DRIVER_ENABLE_FW);
+       host->eject = true;
+       return 0;
+}
+
 static const struct mmc_host_ops realtek_pci_sdmmc_ops = {
        .pre_req = sdmmc_pre_req,
        .post_req = sdmmc_post_req,
@@ -1317,6 +1372,7 @@ static const struct mmc_host_ops realtek_pci_sdmmc_ops = {
        .get_cd = sdmmc_get_cd,
        .start_signal_voltage_switch = sdmmc_switch_voltage,
        .execute_tuning = sdmmc_execute_tuning,
+       .init_sd_express = sdmmc_init_sd_express,
 };
 
 static void init_extra_caps(struct realtek_pci_sdmmc *host)
@@ -1338,6 +1394,8 @@ static void init_extra_caps(struct realtek_pci_sdmmc *host)
                mmc->caps |= MMC_CAP_8_BIT_DATA;
        if (pcr->extra_caps & EXTRA_CAPS_NO_MMC)
                mmc->caps2 |= MMC_CAP2_NO_MMC;
+       if (pcr->extra_caps & EXTRA_CAPS_SD_EXPRESS)
+               mmc->caps2 |= MMC_CAP2_SD_EXP | MMC_CAP2_SD_EXP_1_2V;
 }
 
 static void realtek_init_host(struct realtek_pci_sdmmc *host)