This is a note to let you know that I've just added the patch titled
i3c: master: svc: use slow speed for first broadcast address
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
i3c-master-svc-use-slow-speed-for-first-broadcast-ad.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 437724003fdaf6d9b0bf16895fc182f178249b67
Author: Carlos Song <carlos.song@xxxxxxx>
Date: Tue Sep 10 13:16:26 2024 +0800
i3c: master: svc: use slow speed for first broadcast address
[ Upstream commit 20ade67bb1645f5ce8f37fa79ddfebbc5b5b24ef ]
I3C controller should support adjusting open drain timing for the first
broadcast address to make I3C device working as a i2c device can see slow
broadcast address to close its Spike Filter to change working at i3c mode.
Signed-off-by: Carlos Song <carlos.song@xxxxxxx>
Reviewed-by: Frank Li <frank.li@xxxxxxx>
Link: https://lore.kernel.org/r/20240910051626.4052552-2-carlos.song@xxxxxxx
Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>
Stable-dep-of: 25bc99be5fe5 ("i3c: master: svc: Modify enabled_events bit 7:0 to act as IBI enable counter")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c
index 139b51a575366..97d03d755a61f 100644
--- a/drivers/i3c/master/svc-i3c-master.c
+++ b/drivers/i3c/master/svc-i3c-master.c
@@ -182,6 +182,7 @@ struct svc_i3c_regs_save {
* @ibi.lock: IBI lock
* @lock: Transfer lock, protect between IBI work thread and callbacks from master
* @enabled_events: Bit masks for enable events (IBI, HotJoin).
+ * @mctrl_config: Configuration value in SVC_I3C_MCTRL for setting speed back.
*/
struct svc_i3c_master {
struct i3c_master_controller base;
@@ -212,6 +213,7 @@ struct svc_i3c_master {
} ibi;
struct mutex lock;
int enabled_events;
+ u32 mctrl_config;
};
/**
@@ -529,6 +531,54 @@ static irqreturn_t svc_i3c_master_irq_handler(int irq, void *dev_id)
return IRQ_HANDLED;
}
+static int svc_i3c_master_set_speed(struct i3c_master_controller *m,
+ enum i3c_open_drain_speed speed)
+{
+ struct svc_i3c_master *master = to_svc_i3c_master(m);
+ struct i3c_bus *bus = i3c_master_get_bus(&master->base);
+ u32 ppbaud, odbaud, odhpp, mconfig;
+ unsigned long fclk_rate;
+ int ret;
+
+ ret = pm_runtime_resume_and_get(master->dev);
+ if (ret < 0) {
+ dev_err(master->dev, "<%s> Cannot get runtime PM.\n", __func__);
+ return ret;
+ }
+
+ switch (speed) {
+ case I3C_OPEN_DRAIN_SLOW_SPEED:
+ fclk_rate = clk_get_rate(master->fclk);
+ if (!fclk_rate) {
+ ret = -EINVAL;
+ goto rpm_out;
+ }
+ /*
+ * Set 50% duty-cycle I2C speed to I3C OPEN-DRAIN mode, so the first
+ * broadcast address is visible to all I2C/I3C devices on the I3C bus.
+ * I3C device working as a I2C device will turn off its 50ns Spike
+ * Filter to change to I3C mode.
+ */
+ mconfig = master->mctrl_config;
+ ppbaud = FIELD_GET(GENMASK(11, 8), mconfig);
+ odhpp = 0;
+ odbaud = DIV_ROUND_UP(fclk_rate, bus->scl_rate.i2c * (2 + 2 * ppbaud)) - 1;
+ mconfig &= ~GENMASK(24, 16);
+ mconfig |= SVC_I3C_MCONFIG_ODBAUD(odbaud) | SVC_I3C_MCONFIG_ODHPP(odhpp);
+ writel(mconfig, master->regs + SVC_I3C_MCONFIG);
+ break;
+ case I3C_OPEN_DRAIN_NORMAL_SPEED:
+ writel(master->mctrl_config, master->regs + SVC_I3C_MCONFIG);
+ break;
+ }
+
+rpm_out:
+ pm_runtime_mark_last_busy(master->dev);
+ pm_runtime_put_autosuspend(master->dev);
+
+ return ret;
+}
+
static int svc_i3c_master_bus_init(struct i3c_master_controller *m)
{
struct svc_i3c_master *master = to_svc_i3c_master(m);
@@ -611,6 +661,7 @@ static int svc_i3c_master_bus_init(struct i3c_master_controller *m)
SVC_I3C_MCONFIG_I2CBAUD(i2cbaud);
writel(reg, master->regs + SVC_I3C_MCONFIG);
+ master->mctrl_config = reg;
/* Master core's registration */
ret = i3c_master_get_free_addr(m, 0);
if (ret < 0)
@@ -1620,6 +1671,7 @@ static const struct i3c_master_controller_ops svc_i3c_master_ops = {
.disable_ibi = svc_i3c_master_disable_ibi,
.enable_hotjoin = svc_i3c_master_enable_hotjoin,
.disable_hotjoin = svc_i3c_master_disable_hotjoin,
+ .set_speed = svc_i3c_master_set_speed,
};
static int svc_i3c_master_prepare_clks(struct svc_i3c_master *master)
