From d2e6fb2c31a07f34e5e7533df11431cb0d2ecf9f Mon Sep 17 00:00:00 2001 From: Ricky Wu Date: Tue, 12 Aug 2025 11:08:11 +0800 Subject: 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/misc/cardreader/rtsx_usb.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'drivers/misc') diff --git a/drivers/misc/cardreader/rtsx_usb.c b/drivers/misc/cardreader/rtsx_usb.c index d007a4455ce5..1830e9ed2521 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*/ -- cgit v1.2.3