diff options
| author | Jan Kantert <jan-kernel@kantert.net> | 2026-02-27 14:11:34 +0300 |
|---|---|---|
| committer | Andi Shyti <andi.shyti@kernel.org> | 2026-04-02 00:55:33 +0300 |
| commit | 879766b58ea5cba79ff5fe46f062ed8e05e715aa (patch) | |
| tree | a89fdbb98be2ba53b67b001b266f0e35bcbf3e4e | |
| parent | d3e2c7476e378089d56067202f4d29969fbd47b3 (diff) | |
| download | linux-879766b58ea5cba79ff5fe46f062ed8e05e715aa.tar.xz | |
i2c: rtl9300: add support for 50 kHz and 2.5 MHz bus speeds
Some SFP modules on certain switches (for example the ONTi ONT-S508CL-8S and
XikeStor SKS8300-8X) exhibit unreliable I2C communication at the currently
supported speeds. Add support for 50 kHz and 2.5 MHz I2C bus modes on the
RTL9300 to improve compatibility with these devices.
Signed-off-by: Jan Kantert <jan-kernel@kantert.net>
Reviewed-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/20260227111134.2163701-1-jan-kernel@kantert.net
| -rw-r--r-- | drivers/i2c/busses/i2c-rtl9300.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/drivers/i2c/busses/i2c-rtl9300.c b/drivers/i2c/busses/i2c-rtl9300.c index 672cb978066d..67a5c4228fc9 100644 --- a/drivers/i2c/busses/i2c-rtl9300.c +++ b/drivers/i2c/busses/i2c-rtl9300.c @@ -11,10 +11,16 @@ #include <linux/unaligned.h> enum rtl9300_bus_freq { - RTL9300_I2C_STD_FREQ, - RTL9300_I2C_FAST_FREQ, + RTL9300_I2C_STD_FREQ, // 100kHz + RTL9300_I2C_FAST_FREQ, // 400kHz + RTL9300_I2C_SUPER_FAST_FREQ, // 2.5MHz + RTL9300_I2C_SLOW_FREQ, // 50kHz }; +#define RTL9300_I2C_MAX_SUPER_FAST_FREQ 2500000 +#define RTL9300_I2C_MAX_SLOW_FREQ 50000 + + struct rtl9300_i2c; struct rtl9300_i2c_chan { @@ -433,6 +439,12 @@ static int rtl9300_i2c_probe(struct platform_device *pdev) case I2C_MAX_FAST_MODE_FREQ: chan->bus_freq = RTL9300_I2C_FAST_FREQ; break; + case RTL9300_I2C_MAX_SUPER_FAST_FREQ: + chan->bus_freq = RTL9300_I2C_SUPER_FAST_FREQ; + break; + case RTL9300_I2C_MAX_SLOW_FREQ: + chan->bus_freq = RTL9300_I2C_SLOW_FREQ; + break; default: dev_warn(i2c->dev, "SDA%d clock-frequency %d not supported using default\n", sda_num, clock_freq); |