[PATCH v9 3/5] i2c: davinci: calculate bus freq from Hz instead of kHz

Marcus Folkesson
2026-03-24T13:54:48Z

The bus frequency is unnecessarily converted between Hz and kHz in
several places.
This is probably an old legacy from the old times (pre-devicetrees)
when the davinci_i2c_platform_data took the bus_freq in kHz.

Stick to Hz.

Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
---
drivers/i2c/busses/i2c-davinci.c | 20 +++++++++-----------
1 file changed, 9 insertions(+), 11 deletions(-)

diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c
index a773ba082321..549fb22cdf4f 100644
--- a/drivers/i2c/busses/i2c-davinci.c
+++ b/drivers/i2c/busses/i2c-davinci.c
@@ -117,8 +117,6 @@
/* timeout for pm runtime autosuspend */
#define DAVINCI_I2C_PM_TIMEOUT 1000 /* ms */

-#define DAVINCI_I2C_DEFAULT_BUS_FREQ 100
-
struct davinci_i2c_dev {
struct device *dev;
void __iomem *base;
@@ -134,8 +132,8 @@ struct davinci_i2c_dev {
#ifdef CONFIG_CPU_FREQ
struct notifier_block freq_transition;
#endif
- /* standard bus frequency (kHz) */
- unsigned int bus_freq;
+ /* standard bus frequency */
+ unsigned int bus_freq_hz;
/* Chip has a ICPFUNC register */
bool has_pfunc;
};
@@ -209,16 +207,16 @@ static void i2c_davinci_calc_clk_dividers(struct davinci_i2c_dev *dev)
if (device_is_compatible(dev->dev, "ti,keystone-i2c"))
d = 6;

- clk = ((input_clock / (psc + 1)) / (dev->bus_freq * 1000));
+ clk = (input_clock / (psc + 1)) / (dev->bus_freq_hz);
/* Avoid driving the bus too fast because of rounding errors above */
- if (input_clock / (psc + 1) / clk > dev->bus_freq * 1000)
+ if (input_clock / (psc + 1) / clk > dev->bus_freq_hz)
clk++;
/*
* According to I2C-BUS Spec 2.1, in FAST-MODE LOW period should be at
* least 1.3uS, which is not the case with 50% duty cycle. Driving HIGH
* to LOW ratio as 1 to 2 is more safe.
*/
- if (dev->bus_freq > 100)
+ if (bus_freq_hz > I2C_MAX_STANDARD_MODE_FREQ)
clkl = (clk << 1) / 3;
else
clkl = (clk >> 1);
@@ -242,7 +240,7 @@ static void i2c_davinci_calc_clk_dividers(struct davinci_i2c_dev *dev)
davinci_i2c_write_reg(dev, DAVINCI_I2C_CLKH_REG, clkh);
davinci_i2c_write_reg(dev, DAVINCI_I2C_CLKL_REG, clkl);

- dev_dbg(dev->dev, "input_clock = %d, CLK = %d\n", input_clock, clk);
+ dev_dbg(dev->dev, "input_clock = %u, CLK = %u\n", input_clock, clk);
}

/*
@@ -269,7 +267,7 @@ static int i2c_davinci_init(struct davinci_i2c_dev *dev)
davinci_i2c_read_reg(dev, DAVINCI_I2C_CLKL_REG));
dev_dbg(dev->dev, "CLKH = %d\n",
davinci_i2c_read_reg(dev, DAVINCI_I2C_CLKH_REG));
- dev_dbg(dev->dev, "bus_freq = %dkHz\n", dev->bus_freq);
+ dev_dbg(dev->dev, "bus_freq_hz = %dHz\n", dev->bus_freq_hz);

/* Take the I2C module out of reset: */
@@ -760,9 +758,9 @@ static int davinci_i2c_probe(struct platform_device *pdev)

r = device_property_read_u32(&pdev->dev, "clock-frequency", &prop);
if (r)
- prop = DAVINCI_I2C_DEFAULT_BUS_FREQ;
+ prop = I2C_MAX_STANDARD_MODE_FREQ;

- dev->bus_freq = prop / 1000;
+ dev->bus_freq_hz = prop;

dev->has_pfunc = device_property_present(&pdev->dev, "ti,has-pfunc");

--
2.53.0