[PATCH v3 3/9] i2c: add support for filter-width-ns optional property
From: <Eugen.Hristev@microchip.com>
Date: 2019-07-09 13:20:13
Also in:
linux-devicetree, linux-i2c, lkml
Subsystem:
i2c subsystem, the rest · Maintainers:
Wolfram Sang, Linus Torvalds
From: Eugen Hristev <eugen.hristev@microchip.com> This optional timing property specifies the width of the spikes on the i2c lines (in ns) that can be filtered out by built-in analog or digital filters which are embedded in some i2c controllers. Include it in the timings structure and read it as integer property. Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com> --- drivers/i2c/i2c-core-base.c | 2 ++ include/linux/i2c.h | 2 ++ 2 files changed, 4 insertions(+)
diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index 9e43508..73d1c62 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c@@ -1658,6 +1658,8 @@ void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_de t->sda_fall_ns = t->scl_fall_ns; device_property_read_u32(dev, "i2c-sda-hold-time-ns", &t->sda_hold_ns); + + device_property_read_u32(dev, "i2c-filter-width-ns", &t->filter_width_ns); } EXPORT_SYMBOL_GPL(i2c_parse_fw_timings);
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 1308126..dfb6525 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h@@ -563,6 +563,7 @@ struct i2c_lock_operations { * @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns * @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification * @sda_hold_ns: time IP core additionally needs to hold SDA in ns + * @filter_width_ns: width in ns of spikes on i2c lines that the IP core can filter out */ struct i2c_timings { u32 bus_freq_hz;
@@ -571,6 +572,7 @@ struct i2c_timings { u32 scl_int_delay_ns; u32 sda_fall_ns; u32 sda_hold_ns; + u32 filter_width_ns; }; /**
--
2.7.4
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