Commit 9449a558 authored by Alain Volmat's avatar Alain Volmat Committed by Wolfram Sang
Browse files

i2c: stm32f7: add support for DNF i2c-digital-filter binding 



Add the support for the i2c-digital-filter binding, allowing to enable
the digital filter via the device-tree and indicate its value in the DT.

Signed-off-by: default avatarAlain Volmat <alain.volmat@foss.st.com>
Reviewed-by: default avatarPierre-Yves MORDRET <pierre-yves.mordret@foss.st.com>
Signed-off-by: default avatarWolfram Sang <wsa@kernel.org>
parent 83c3408f

drivers/i2c/busses/i2c-stm32f7.c

+16 −11
Original line number Diff line number Diff line
@@ -222,7 +222,6 @@ struct stm32f7_i2c_spec { 
 * @clock_src: I2C clock source frequency (Hz)

 * @rise_time: Rise time (ns)

 * @fall_time: Fall time (ns)

 * @dnf: Digital filter coefficient (0-16)

 * @fmp_clr_offset: Fast Mode Plus clear register offset from set register

 */

struct stm32f7_i2c_setup {
@@ -230,7 +229,6 @@ struct stm32f7_i2c_setup { 
	u32 clock_src;

	u32 rise_time;

	u32 fall_time;

	u8 dnf;

	u32 fmp_clr_offset;

};
@@ -310,6 +308,8 @@ struct stm32f7_i2c_msg { 
 * @smbus_mode: states that the controller is configured in SMBus mode

 * @host_notify_client: SMBus host-notify client

 * @analog_filter: boolean to indicate enabling of the analog filter

 * @dnf_dt: value of digital filter requested via dt

 * @dnf: value of digital filter to apply

 */

struct stm32f7_i2c_dev {

	struct i2c_adapter adap;
@@ -339,6 +339,8 @@ struct stm32f7_i2c_dev { 
	bool smbus_mode;

	struct i2c_client *host_notify_client;

	bool analog_filter;

	u32 dnf_dt;

	u32 dnf;

};



/*
@@ -384,13 +386,11 @@ static struct stm32f7_i2c_spec stm32f7_i2c_specs[] = { 
static const struct stm32f7_i2c_setup stm32f7_setup = {

	.rise_time = STM32F7_I2C_RISE_TIME_DEFAULT,

	.fall_time = STM32F7_I2C_FALL_TIME_DEFAULT,

	.dnf = STM32F7_I2C_DNF_DEFAULT,

};



static const struct stm32f7_i2c_setup stm32mp15_setup = {

	.rise_time = STM32F7_I2C_RISE_TIME_DEFAULT,

	.fall_time = STM32F7_I2C_FALL_TIME_DEFAULT,

	.dnf = STM32F7_I2C_DNF_DEFAULT,

	.fmp_clr_offset = 0x40,

};
@@ -459,10 +459,11 @@ static int stm32f7_i2c_compute_timing(struct stm32f7_i2c_dev *i2c_dev, 
		return -EINVAL;

	}



	if (setup->dnf > STM32F7_I2C_DNF_MAX) {

	i2c_dev->dnf = DIV_ROUND_CLOSEST(i2c_dev->dnf_dt, i2cclk);

	if (i2c_dev->dnf > STM32F7_I2C_DNF_MAX) {

		dev_err(i2c_dev->dev,

			"DNF out of bound %d/%d\n",

			setup->dnf, STM32F7_I2C_DNF_MAX);

			i2c_dev->dnf * i2cclk, STM32F7_I2C_DNF_MAX * i2cclk);

		return -EINVAL;

	}
@@ -473,13 +474,13 @@ static int stm32f7_i2c_compute_timing(struct stm32f7_i2c_dev *i2c_dev, 
	af_delay_max =

		(i2c_dev->analog_filter ?

		 STM32F7_I2C_ANALOG_FILTER_DELAY_MAX : 0);

	dnf_delay = setup->dnf * i2cclk;

	dnf_delay = i2c_dev->dnf * i2cclk;



	sdadel_min = specs->hddat_min + setup->fall_time -

		af_delay_min - (setup->dnf + 3) * i2cclk;

		af_delay_min - (i2c_dev->dnf + 3) * i2cclk;



	sdadel_max = specs->vddat_max - setup->rise_time -

		af_delay_max - (setup->dnf + 4) * i2cclk;

		af_delay_max - (i2c_dev->dnf + 4) * i2cclk;



	scldel_min = setup->rise_time + specs->sudat_min;
@@ -645,6 +646,7 @@ static int stm32f7_i2c_setup_timing(struct stm32f7_i2c_dev *i2c_dev, 
	setup->speed_freq = t->bus_freq_hz;

	i2c_dev->setup.rise_time = t->scl_rise_ns;

	i2c_dev->setup.fall_time = t->scl_fall_ns;

	i2c_dev->dnf_dt = t->digital_filter_width_ns;

	setup->clock_src = clk_get_rate(i2c_dev->clk);



	if (!setup->clock_src) {
@@ -652,6 +654,9 @@ static int stm32f7_i2c_setup_timing(struct stm32f7_i2c_dev *i2c_dev, 
		return -EINVAL;

	}



	if (!of_property_read_bool(i2c_dev->dev->of_node, "i2c-digital-filter"))

		i2c_dev->dnf_dt = STM32F7_I2C_DNF_DEFAULT;



	do {

		ret = stm32f7_i2c_compute_timing(i2c_dev, setup,

						 &i2c_dev->timing);
@@ -681,7 +686,7 @@ static int stm32f7_i2c_setup_timing(struct stm32f7_i2c_dev *i2c_dev, 
	dev_dbg(i2c_dev->dev, "I2C Rise(%i) and Fall(%i) Time\n",

		setup->rise_time, setup->fall_time);

	dev_dbg(i2c_dev->dev, "I2C Analog Filter(%s), DNF(%i)\n",

		(i2c_dev->analog_filter ? "On" : "Off"), setup->dnf);

		(i2c_dev->analog_filter ? "On" : "Off"), i2c_dev->dnf);



	i2c_dev->bus_rate = setup->speed_freq;
@@ -732,7 +737,7 @@ static void stm32f7_i2c_hw_config(struct stm32f7_i2c_dev *i2c_dev) 
	stm32f7_i2c_clr_bits(i2c_dev->base + STM32F7_I2C_CR1,

			     STM32F7_I2C_CR1_DNF_MASK);

	stm32f7_i2c_set_bits(i2c_dev->base + STM32F7_I2C_CR1,

			     STM32F7_I2C_CR1_DNF(i2c_dev->setup.dnf));

			     STM32F7_I2C_CR1_DNF(i2c_dev->dnf));



	stm32f7_i2c_set_bits(i2c_dev->base + STM32F7_I2C_CR1,

			     STM32F7_I2C_CR1_PE);