From 6338b458887021dbea718d7bee973569a2e62bf5 Mon Sep 17 00:00:00 2001 From: Patrick Delaunay Date: Tue, 3 Aug 2021 12:05:14 +0200 Subject: [PATCH] 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: Patrick Delaunay Signed-off-by: Patrice Chotard Reviewed-by: Patrice Chotard --- drivers/i2c/stm32f7_i2c.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/i2c/stm32f7_i2c.c b/drivers/i2c/stm32f7_i2c.c index 7e6c65f..2b2dae6 100644 --- a/drivers/i2c/stm32f7_i2c.c +++ b/drivers/i2c/stm32f7_i2c.c @@ -107,7 +107,6 @@ struct stm32_i2c_regs { #define STM32_I2C_MAX_LEN 0xff -#define STM32_I2C_DNF_DEFAULT 0 #define STM32_I2C_DNF_MAX 15 #define STM32_I2C_ANALOG_FILTER_DELAY_MIN 50 /* ns */ @@ -204,6 +203,7 @@ struct stm32_i2c_timings { * @regmap_sreg: register address for setting Fast Mode Plus bits * @regmap_creg: register address for clearing Fast Mode Plus bits * @regmap_mask: mask for Fast Mode Plus bits + * @dnf_dt: value of digital filter requested via dt */ struct stm32_i2c_priv { struct stm32_i2c_regs *regs; @@ -214,6 +214,7 @@ struct stm32_i2c_priv { u32 regmap_sreg; u32 regmap_creg; u32 regmap_mask; + u32 dnf_dt; }; static const struct stm32_i2c_spec i2c_specs[] = { @@ -684,6 +685,7 @@ static int stm32_i2c_compute_timing(struct stm32_i2c_priv *i2c_priv, const struct stm32_i2c_spec *specs; struct stm32_i2c_timings *v, *_v; struct list_head solutions; + u32 i2cclk = DIV_ROUND_CLOSEST(STM32_NSEC_PER_SEC, setup->clock_src); int ret; specs = get_specs(setup->speed_freq); @@ -701,6 +703,8 @@ static int stm32_i2c_compute_timing(struct stm32_i2c_priv *i2c_priv, return -EINVAL; } + /* Analog and Digital Filters */ + setup->dnf = DIV_ROUND_CLOSEST(i2c_priv->dnf_dt, i2cclk); if (setup->dnf > STM32_I2C_DNF_MAX) { log_err("DNF out of bound %d/%d\n", setup->dnf, STM32_I2C_DNF_MAX); @@ -923,7 +927,10 @@ static int stm32_of_to_plat(struct udevice *dev) fall_time = dev_read_u32_default(dev, "i2c-scl-falling-time-ns", STM32_I2C_FALL_TIME_DEFAULT); - i2c_priv->setup.dnf = STM32_I2C_DNF_DEFAULT; + i2c_priv->dnf_dt = dev_read_u32_default(dev, "i2c-digital-filter-width-ns", 0); + if (!dev_read_bool(dev, "i2c-digital-filter")) + i2c_priv->dnf_dt = 0; + i2c_priv->setup.analog_filter = dev_read_bool(dev, "i2c-analog-filter"); /* Optional */ -- 2.7.4