From e6b66e9f338fe9c8a6bc498399e736f7ec9deb10 Mon Sep 17 00:00:00 2001 From: Kaustabh Chakraborty Date: Fri, 17 Oct 2025 20:54:09 +0530 Subject: mmc: dw_mmc: add voltage switch command flag During a voltage switch command (CMD11, opcode: SD_CMD_SWITCH_UHS18V), certain hosts tend to stop responding to subsequent commands. This is addressed by introducing an additional command flag, DWMCI_CMD_VOLT_SWITCH. The associated interrupt bit is defined as DWMCI_INTMSK_VOLTSW. This is set high when a voltage switch is issued, this needs to be waited for and set to low. Implement the same in the timeout loop. Do note that since DWMCI_INTMSK_VOLTSW shares the same bit as DWMCI_INTMSK_HTO (bit 10), the interrupt bit needs to be polled for only if the volt switch command is issued. DWMCI_CMD_VOLT_SWITCH also needs to be set for subsequent clken commands after the volt switch. To ensure this, add a boolean member in the host private struct (herein named volt_switching), which informs if the last command issued was for volt switching or not. Signed-off-by: Kaustabh Chakraborty Signed-off-by: Peng Fan --- drivers/mmc/dw_mmc.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) (limited to 'drivers') diff --git a/drivers/mmc/dw_mmc.c b/drivers/mmc/dw_mmc.c index 1aa992c352c..94b6641c44c 100644 --- a/drivers/mmc/dw_mmc.c +++ b/drivers/mmc/dw_mmc.c @@ -419,6 +419,10 @@ static int dwmci_send_cmd_common(struct dwmci_host *host, struct mmc_cmd *cmd, if (cmd->resp_type & MMC_RSP_CRC) flags |= DWMCI_CMD_CHECK_CRC; + host->volt_switching = (cmd->cmdidx == SD_CMD_SWITCH_UHS18V); + if (host->volt_switching) + flags |= DWMCI_CMD_VOLT_SWITCH; + flags |= cmd->cmdidx | DWMCI_CMD_START | DWMCI_CMD_USE_HOLD_REG; debug("Sending CMD%d\n", cmd->cmdidx); @@ -427,6 +431,10 @@ static int dwmci_send_cmd_common(struct dwmci_host *host, struct mmc_cmd *cmd, for (i = 0; i < retry; i++) { mask = dwmci_readl(host, DWMCI_RINTSTS); + if (host->volt_switching && (mask & DWMCI_INTMSK_VOLTSW)) { + dwmci_writel(host, DWMCI_RINTSTS, DWMCI_INTMSK_VOLTSW); + break; + } if (mask & DWMCI_INTMSK_CDONE) { if (!data) dwmci_writel(host, DWMCI_RINTSTS, mask); @@ -508,12 +516,15 @@ static int dwmci_control_clken(struct dwmci_host *host, bool on) const u32 val = on ? DWMCI_CLKEN_ENABLE | DWMCI_CLKEN_LOW_PWR : 0; const u32 cmd_only_clk = DWMCI_CMD_PRV_DAT_WAIT | DWMCI_CMD_UPD_CLK; int i, timeout = 10000; - u32 mask; + u32 flags, mask; dwmci_writel(host, DWMCI_CLKENA, val); /* Inform CIU */ - dwmci_writel(host, DWMCI_CMD, DWMCI_CMD_START | cmd_only_clk); + flags = DWMCI_CMD_START | cmd_only_clk; + if (host->volt_switching) + flags |= DWMCI_CMD_VOLT_SWITCH; + dwmci_writel(host, DWMCI_CMD, flags); for (i = 0; i < timeout; i++) { mask = dwmci_readl(host, DWMCI_RINTSTS); -- cgit v1.2.3