From 4bfba7b360da70ed209969848bbe6e750254a759 Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Mon, 8 Jun 2026 08:43:11 +0300 Subject: [PATCH] i3c: master: Export i3c_master_enec_disec_locked() The existing i3c_master_enec_locked() wrapper always treats a NACKed ENEC CCC as a failure (M2 error). However, broadcasting ENEC to enable Hot-Join is legitimately useful even when no I3C devices are currently present on the bus, in which case the broadcast will be NACKed and should not be reported as an error. The underlying helper i3c_master_enec_disec_locked() already accepts a suppress_m2 flag that lets callers ignore such NACKs. Expose it so that a subsequent patch enabling Hot-Join events can issue ENEC with M2 suppression. Signed-off-by: Adrian Hunter Reviewed-by: Frank Li Link: https://patch.msgid.link/20260608054312.10604-8-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni --- drivers/i3c/master.c | 27 ++++++++++++++++++++++++--- include/linux/i3c/master.h | 2 ++ 2 files changed, 26 insertions(+), 3 deletions(-) diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c index ed749f9ee413..9f8d99636f69 100644 --- a/drivers/i3c/master.c +++ b/drivers/i3c/master.c @@ -1121,9 +1121,29 @@ int i3c_master_entdaa_locked(struct i3c_master_controller *master) } EXPORT_SYMBOL_GPL(i3c_master_entdaa_locked); -static int i3c_master_enec_disec_locked(struct i3c_master_controller *master, - u8 addr, bool enable, u8 evts, - bool suppress_m2) +/** + * i3c_master_enec_disec_locked() - send an ENEC or DISEC CCC command + * @master: master used to send frames on the bus + * @addr: a valid I3C slave address or %I3C_BROADCAST_ADDR + * @enable: true to send ENEC, false to send DISEC + * @evts: events to enable or disable + * @suppress_m2: if true, treat an M2 (NACK) error from the CCC as success + * + * Send an ENEC or DISEC CCC command to enable or disable some or all events + * coming from a specific slave, or all devices if @addr is + * %I3C_BROADCAST_ADDR. + * + * When @suppress_m2 is true, a NACK of the broadcast (which can happen when + * no devices are present on the bus) is not reported as an error. This is + * useful for callers that want to configure event reporting unconditionally, + * regardless of whether any devices are currently on the bus. + * + * This function must be called with the bus lock held in write mode. + * + * Return: 0 in case of success, or a negative error code otherwise. + */ +int i3c_master_enec_disec_locked(struct i3c_master_controller *master, u8 addr, + bool enable, u8 evts, bool suppress_m2) { struct i3c_ccc_events *events; struct i3c_ccc_cmd_dest dest; @@ -1148,6 +1168,7 @@ static int i3c_master_enec_disec_locked(struct i3c_master_controller *master, return ret; } +EXPORT_SYMBOL_GPL(i3c_master_enec_disec_locked); /** * i3c_master_disec_locked() - send a DISEC CCC command diff --git a/include/linux/i3c/master.h b/include/linux/i3c/master.h index 8cdd7be505d3..e2c831fb5354 100644 --- a/include/linux/i3c/master.h +++ b/include/linux/i3c/master.h @@ -607,6 +607,8 @@ int i3c_master_disec_locked(struct i3c_master_controller *master, u8 addr, u8 evts); int i3c_master_enec_locked(struct i3c_master_controller *master, u8 addr, u8 evts); +int i3c_master_enec_disec_locked(struct i3c_master_controller *master, u8 addr, + bool enable, u8 evts, bool suppress_m2); int i3c_master_entdaa_locked(struct i3c_master_controller *master); int i3c_master_defslvs_locked(struct i3c_master_controller *master);