From d2e6fb2c31a07f34e5e7533df11431cb0d2ecf9f Mon Sep 17 00:00:00 2001 From: Ricky Wu Date: Tue, 12 Aug 2025 11:08:11 +0800 Subject: [PATCH] misc: rtsx: usb card reader: add OCP support This patch adds support for Over Current Protection (OCP) to the Realtek USB card reader driver. The OCP mechanism protects the hardware by detecting and handling current overload conditions. This implementation includes: - Register configurations to enable OCP monitoring. - Handling of OCP interrupt events and associated error reporting. - Card power management changes in response to OCP triggers. This enhancement improves the robustness of the driver when operating in environments where electrical anomalies may occur, particularly with SD and MS card interfaces. Signed-off-by: Ricky Wu Link: https://lore.kernel.org/r/20250812030811.2426112-1-ricky_wu@realtek.com Signed-off-by: Ulf Hansson --- drivers/memstick/host/rtsx_usb_ms.c | 5 ++++- drivers/misc/cardreader/rtsx_usb.c | 7 ++++++ drivers/mmc/host/rtsx_usb_sdmmc.c | 33 ++++++++++++++++++++++++++--- include/linux/rtsx_usb.h | 11 ++++++++++ 4 files changed, 52 insertions(+), 4 deletions(-) diff --git a/drivers/memstick/host/rtsx_usb_ms.c b/drivers/memstick/host/rtsx_usb_ms.c index 3878136227e49..9389e9643c245 100644 --- a/drivers/memstick/host/rtsx_usb_ms.c +++ b/drivers/memstick/host/rtsx_usb_ms.c @@ -216,7 +216,10 @@ static int ms_power_off(struct rtsx_usb_ms *host) rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_CLK_EN, MS_CLK_EN, 0); rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_OE, MS_OUTPUT_EN, 0); - + rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_PWR_CTL, + POWER_MASK, POWER_OFF); + rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_PWR_CTL, + POWER_MASK | LDO3318_PWR_MASK, POWER_OFF | LDO_SUSPEND); err = rtsx_usb_send_cmd(ucr, MODE_C, 100); if (err < 0) return err; diff --git a/drivers/misc/cardreader/rtsx_usb.c b/drivers/misc/cardreader/rtsx_usb.c index d007a4455ce5b..1830e9ed25216 100644 --- a/drivers/misc/cardreader/rtsx_usb.c +++ b/drivers/misc/cardreader/rtsx_usb.c @@ -552,6 +552,10 @@ static int rtsx_usb_reset_chip(struct rtsx_ucr *ucr) ret = rtsx_usb_send_cmd(ucr, MODE_C, 100); if (ret) return ret; + /* config OCP */ + rtsx_usb_write_register(ucr, OCPCTL, MS_OCP_DETECT_EN, MS_OCP_DETECT_EN); + rtsx_usb_write_register(ucr, OCPPARA1, 0xF0, 0x50); + rtsx_usb_write_register(ucr, OCPPARA2, 0x7, 0x3); /* config non-crystal mode */ rtsx_usb_read_register(ucr, CFG_MODE, &val); @@ -722,6 +726,9 @@ static int rtsx_usb_suspend(struct usb_interface *intf, pm_message_t message) if (val & (SD_CD | MS_CD)) { device_for_each_child(&intf->dev, NULL, rtsx_usb_resume_child); return -EAGAIN; + } else { + /* if the card does not exists, clear OCP status */ + rtsx_usb_write_register(ucr, OCPCTL, MS_OCP_CLEAR, MS_OCP_CLEAR); } } else { /* There is an ongoing operation*/ diff --git a/drivers/mmc/host/rtsx_usb_sdmmc.c b/drivers/mmc/host/rtsx_usb_sdmmc.c index c5f6b9df066b5..e1ed39c657c37 100644 --- a/drivers/mmc/host/rtsx_usb_sdmmc.c +++ b/drivers/mmc/host/rtsx_usb_sdmmc.c @@ -48,7 +48,7 @@ struct rtsx_usb_sdmmc { bool ddr_mode; unsigned char power_mode; - + u16 ocp_stat; #ifdef RTSX_USB_USE_LEDS_CLASS struct led_classdev led; char led_name[32]; @@ -785,6 +785,9 @@ static int sdmmc_get_cd(struct mmc_host *mmc) mutex_unlock(&ucr->dev_mutex); + /* get OCP status */ + host->ocp_stat = (val >> 4) & 0x03; + /* Treat failed detection as non-exist */ if (err) goto no_card; @@ -795,6 +798,11 @@ static int sdmmc_get_cd(struct mmc_host *mmc) } no_card: + /* clear OCP status */ + if (host->ocp_stat & (MS_OCP_NOW | MS_OCP_EVER)) { + rtsx_usb_write_register(ucr, OCPCTL, MS_OCP_CLEAR, MS_OCP_CLEAR); + host->ocp_stat = 0; + } host->card_exist = false; return 0; } @@ -818,7 +826,11 @@ static void sdmmc_request(struct mmc_host *mmc, struct mmc_request *mrq) cmd->error = -ENOMEDIUM; goto finish_detect_card; } - + /* check OCP stat */ + if (host->ocp_stat & (MS_OCP_NOW | MS_OCP_EVER)) { + cmd->error = -ENOMEDIUM; + goto finish_detect_card; + } mutex_lock(&ucr->dev_mutex); mutex_lock(&host->host_mutex); @@ -952,6 +964,10 @@ static int sd_power_on(struct rtsx_usb_sdmmc *host) struct rtsx_ucr *ucr = host->ucr; int err; + if (host->ocp_stat & (MS_OCP_NOW | MS_OCP_EVER)) { + dev_dbg(sdmmc_dev(host), "over current\n"); + return -EIO; + } dev_dbg(sdmmc_dev(host), "%s\n", __func__); rtsx_usb_init_cmd(ucr); rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_SELECT, 0x07, SD_MOD_SEL); @@ -977,9 +993,19 @@ static int sd_power_on(struct rtsx_usb_sdmmc *host) usleep_range(800, 1000); + rtsx_usb_init_cmd(ucr); + /* WA OCP issue: after OCP, there were problems with reopen card power */ + rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_PWR_CTL, POWER_MASK, POWER_ON); + rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, FPDCTL, SSC_POWER_MASK, SSC_POWER_DOWN); + err = rtsx_usb_send_cmd(ucr, MODE_C, 100); + if (err) + return err; + msleep(20); + rtsx_usb_write_register(ucr, FPDCTL, SSC_POWER_MASK, SSC_POWER_ON); + usleep_range(180, 200); rtsx_usb_init_cmd(ucr); rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_PWR_CTL, - POWER_MASK|LDO3318_PWR_MASK, POWER_ON|LDO_ON); + LDO3318_PWR_MASK, LDO_ON); rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_OE, SD_OUTPUT_EN, SD_OUTPUT_EN); @@ -1332,6 +1358,7 @@ static void rtsx_usb_init_host(struct rtsx_usb_sdmmc *host) mmc->max_req_size = 524288; host->power_mode = MMC_POWER_OFF; + host->ocp_stat = 0; } static int rtsx_usb_sdmmc_drv_probe(struct platform_device *pdev) diff --git a/include/linux/rtsx_usb.h b/include/linux/rtsx_usb.h index f267a06c6b1e7..276b509c03e36 100644 --- a/include/linux/rtsx_usb.h +++ b/include/linux/rtsx_usb.h @@ -99,6 +99,17 @@ extern int rtsx_usb_card_exclusive_check(struct rtsx_ucr *ucr, int card); #define CD_MASK (SD_CD | MS_CD | XD_CD) #define SD_WP 0x08 +/* OCPCTL */ +#define MS_OCP_DETECT_EN 0x08 +#define MS_OCP_INT_EN 0x04 +#define MS_OCP_INT_CLR 0x02 +#define MS_OCP_CLEAR 0x01 + +/* OCPSTAT */ +#define MS_OCP_DETECT 0x80 +#define MS_OCP_NOW 0x02 +#define MS_OCP_EVER 0x01 + /* reader command field offset & parameters */ #define READ_REG_CMD 0 #define WRITE_REG_CMD 1 -- 2.47.3