Commit 263a5646 authored by Andy Shevchenko's avatar Andy Shevchenko Committed by Wolfram Sang
Browse files

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: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: default avatarWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
parent e6282fc6

drivers/i2c/busses/i2c-rcar.c

+1 −1
Original line number Diff line number Diff line
@@ -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 */

drivers/i2c/i2c-core-base.c

+17 −13
Original line number Diff line number Diff line
@@ -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);