This is a note to let you know that I've just added the patch titled
i2c: core: Provide generic definitions for bus frequencies
to the 5.4-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:
i2c-core-provide-generic-definitions-for-bus-frequen.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit f691d0cbdf9b9b179ffef64a78ada25c3e42d2ff
Author: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Date: Tue Mar 24 14:32:11 2020 +0200
i2c: core: Provide generic definitions for bus frequencies
[ Upstream commit e6282fc6f889debe4d6eb6332dc6e49739faa5cb ]
There are few maximum bus frequencies being used in the I²C core code.
Provide generic definitions for bus frequencies and use them in the core.
The drivers may use predefined constants where it is appropriate.
Some of them are already using these under slightly different names.
We will convert them later to use newly introduced defines.
Note, the name of modes are chosen to follow well established naming
scheme [1].
These definitions will also help to avoid typos in the numbers that
may lead to subtle errors.
[1]: https://en.wikipedia.org/wiki/I%C2%B2C#Differences_between_modes
Acked-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Signed-off-by: Wolfram Sang <wsa@xxxxxxxxxxxxx>
Stable-dep-of: cbf3fb5b29e9 ("i2c: designware: Fix the functionality flags of the slave-only interface")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/i2c/i2c-core-acpi.c b/drivers/i2c/i2c-core-acpi.c
index fe466ee4c49bf..17640e2230b61 100644
--- a/drivers/i2c/i2c-core-acpi.c
+++ b/drivers/i2c/i2c-core-acpi.c
@@ -328,7 +328,7 @@ static acpi_status i2c_acpi_lookup_speed(acpi_handle handle, u32 level,
lookup->min_speed = lookup->speed;
if (acpi_match_device_ids(adev, i2c_acpi_force_400khz_device_ids) == 0)
- lookup->force_speed = 400000;
+ lookup->force_speed = I2C_MAX_FAST_MODE_FREQ;
return AE_OK;
}
diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index cf9ad03bb34de..4972cc0f9f9ac 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -1650,13 +1650,13 @@ void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_de
ret = device_property_read_u32(dev, "clock-frequency", &t->bus_freq_hz);
if (ret && use_defaults)
- t->bus_freq_hz = 100000;
+ t->bus_freq_hz = I2C_MAX_STANDARD_MODE_FREQ;
ret = device_property_read_u32(dev, "i2c-scl-rising-time-ns", &t->scl_rise_ns);
if (ret && use_defaults) {
- if (t->bus_freq_hz <= 100000)
+ if (t->bus_freq_hz <= I2C_MAX_STANDARD_MODE_FREQ)
t->scl_rise_ns = 1000;
- else if (t->bus_freq_hz <= 400000)
+ else if (t->bus_freq_hz <= I2C_MAX_FAST_MODE_FREQ)
t->scl_rise_ns = 300;
else
t->scl_rise_ns = 120;
@@ -1664,7 +1664,7 @@ void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_de
ret = device_property_read_u32(dev, "i2c-scl-falling-time-ns", &t->scl_fall_ns);
if (ret && use_defaults) {
- if (t->bus_freq_hz <= 400000)
+ if (t->bus_freq_hz <= I2C_MAX_FAST_MODE_FREQ)
t->scl_fall_ns = 300;
else
t->scl_fall_ns = 120;
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index af2b799d7a665..3d0008c41bed8 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -39,6 +39,14 @@ enum i2c_slave_event;
typedef int (*i2c_slave_cb_t)(struct i2c_client *client,
enum i2c_slave_event event, u8 *val);
+/* I2C Frequency Modes */
+#define I2C_MAX_STANDARD_MODE_FREQ 100000
+#define I2C_MAX_FAST_MODE_FREQ 400000
+#define I2C_MAX_FAST_MODE_PLUS_FREQ 1000000
+#define I2C_MAX_TURBO_MODE_FREQ 1400000
+#define I2C_MAX_HIGH_SPEED_MODE_FREQ 3400000
+#define I2C_MAX_ULTRA_FAST_MODE_FREQ 5000000
+
struct module;
struct property_entry;
