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authorAndy Shevchenko <andriy.shevchenko@linux.intel.com>2020-03-24 15:32:12 +0300
committerWolfram Sang <wsa@the-dreams.de>2020-03-24 23:59:10 +0300
commit263a5646d88506c82850d824e673b14698ebad6b (patch)
treedd169df63aa4390c0987f7786c74c7ee8abd37ea /drivers/i2c
parente6282fc6f889debe4d6eb6332dc6e49739faa5cb (diff)
downloadlinux-263a5646d88506c82850d824e673b14698ebad6b.tar.xz
i2c: core: Allow override timing properties with 0
Some drivers may allow to override properties with 0 value when defaults are not in use, thus, replace memset() with corresponding per property update. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/i2c')
-rw-r--r--drivers/i2c/busses/i2c-rcar.c2
-rw-r--r--drivers/i2c/i2c-core-base.c30
2 files changed, 18 insertions, 14 deletions
diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c
index 879f0e61a496..c8b57ded0e7b 100644
--- a/drivers/i2c/busses/i2c-rcar.c
+++ b/drivers/i2c/busses/i2c-rcar.c
@@ -920,7 +920,7 @@ static int rcar_i2c_probe(struct platform_device *pdev)
struct rcar_i2c_priv *priv;
struct i2c_adapter *adap;
struct device *dev = &pdev->dev;
- struct i2c_timings i2c_t;
+ struct i2c_timings i2c_t = { 0 };
int ret;
/* Otherwise logic will break because some bytes must always use PIO */
diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index 9b2972c7faa2..5cc0b0ec5570 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -1593,23 +1593,21 @@ EXPORT_SYMBOL(i2c_del_adapter);
* @dev: The device to scan for I2C timing properties
* @t: the i2c_timings struct to be filled with values
* @use_defaults: bool to use sane defaults derived from the I2C specification
- * when properties are not found, otherwise use 0
+ * when properties are not found, otherwise don't update
*
* Scan the device for the generic I2C properties describing timing parameters
* for the signal and fill the given struct with the results. If a property was
* not found and use_defaults was true, then maximum timings are assumed which
* are derived from the I2C specification. If use_defaults is not used, the
- * results will be 0, so drivers can apply their own defaults later. The latter
- * is mainly intended for avoiding regressions of existing drivers which want
- * to switch to this function. New drivers almost always should use the defaults.
+ * results will be as before, so drivers can apply their own defaults before
+ * calling this helper. The latter is mainly intended for avoiding regressions
+ * of existing drivers which want to switch to this function. New drivers
+ * almost always should use the defaults.
*/
-
void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults)
{
int ret;
- memset(t, 0, sizeof(*t));
-
ret = device_property_read_u32(dev, "clock-frequency", &t->bus_freq_hz);
if (ret && use_defaults)
t->bus_freq_hz = I2C_MAX_STANDARD_MODE_FREQ;
@@ -1632,19 +1630,25 @@ void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_de
t->scl_fall_ns = 120;
}
- device_property_read_u32(dev, "i2c-scl-internal-delay-ns", &t->scl_int_delay_ns);
+ ret = device_property_read_u32(dev, "i2c-scl-internal-delay-ns", &t->scl_int_delay_ns);
+ if (ret && use_defaults)
+ t->scl_int_delay_ns = 0;
ret = device_property_read_u32(dev, "i2c-sda-falling-time-ns", &t->sda_fall_ns);
if (ret && use_defaults)
t->sda_fall_ns = t->scl_fall_ns;
- device_property_read_u32(dev, "i2c-sda-hold-time-ns", &t->sda_hold_ns);
+ ret = device_property_read_u32(dev, "i2c-sda-hold-time-ns", &t->sda_hold_ns);
+ if (ret && use_defaults)
+ t->sda_hold_ns = 0;
- device_property_read_u32(dev, "i2c-digital-filter-width-ns",
- &t->digital_filter_width_ns);
+ ret = device_property_read_u32(dev, "i2c-digital-filter-width-ns", &t->digital_filter_width_ns);
+ if (ret && use_defaults)
+ t->digital_filter_width_ns = 0;
- device_property_read_u32(dev, "i2c-analog-filter-cutoff-frequency",
- &t->analog_filter_cutoff_freq_hz);
+ ret = device_property_read_u32(dev, "i2c-analog-filter-cutoff-frequency", &t->analog_filter_cutoff_freq_hz);
+ if (ret && use_defaults)
+ t->analog_filter_cutoff_freq_hz = 0;
}
EXPORT_SYMBOL_GPL(i2c_parse_fw_timings);