This is a note to let you know that I've just added the patch titled
i3c: master: cdns: Update maximum prescaler value for i2c clock
to the 6.1-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-cdns-update-maximum-prescaler-value-for-i.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit feb9a5f2c6a71d63226dd4f557bd1bc57ad4ed88
Author: Harshit Shah <harshitshah.opendev@xxxxxxxxx>
Date: Sat Dec 30 14:41:23 2023 +0530
i3c: master: cdns: Update maximum prescaler value for i2c clock
[ Upstream commit 374c13f9080a1b9835a5ed3e7bea93cf8e2dc262 ]
As per the Cadence IP document fixed the I2C clock divider value limit from
16 bits instead of 10 bits. Without this change setting up the I2C clock to
low frequencies will not work as the prescaler value might be greater than
10 bit number.
I3C clock divider value is 10 bits only. Updating the macro names for both.
Signed-off-by: Harshit Shah <harshitshah.opendev@xxxxxxxxx>
Link: https://lore.kernel.org/r/1703927483-28682-1-git-send-email-harshitshah.opendev@xxxxxxxxx
Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/i3c/master/i3c-master-cdns.c b/drivers/i3c/master/i3c-master-cdns.c
index 4a49c75a9408..b9cfda6ae9ae 100644
--- a/drivers/i3c/master/i3c-master-cdns.c
+++ b/drivers/i3c/master/i3c-master-cdns.c
@@ -77,7 +77,8 @@
#define PRESCL_CTRL0 0x14
#define PRESCL_CTRL0_I2C(x) ((x) << 16)
#define PRESCL_CTRL0_I3C(x) (x)
-#define PRESCL_CTRL0_MAX GENMASK(9, 0)
+#define PRESCL_CTRL0_I3C_MAX GENMASK(9, 0)
+#define PRESCL_CTRL0_I2C_MAX GENMASK(15, 0)
#define PRESCL_CTRL1 0x18
#define PRESCL_CTRL1_PP_LOW_MASK GENMASK(15, 8)
@@ -1234,7 +1235,7 @@ static int cdns_i3c_master_bus_init(struct i3c_master_controller *m)
return -EINVAL;
pres = DIV_ROUND_UP(sysclk_rate, (bus->scl_rate.i3c * 4)) - 1;
- if (pres > PRESCL_CTRL0_MAX)
+ if (pres > PRESCL_CTRL0_I3C_MAX)
return -ERANGE;
bus->scl_rate.i3c = sysclk_rate / ((pres + 1) * 4);
@@ -1247,7 +1248,7 @@ static int cdns_i3c_master_bus_init(struct i3c_master_controller *m)
max_i2cfreq = bus->scl_rate.i2c;
pres = (sysclk_rate / (max_i2cfreq * 5)) - 1;
- if (pres > PRESCL_CTRL0_MAX)
+ if (pres > PRESCL_CTRL0_I2C_MAX)
return -ERANGE;
bus->scl_rate.i2c = sysclk_rate / ((pres + 1) * 5);
