Hi Andy: Thanks for your reply. On Tue, Feb 18, 2025 at 7:34 PM Andy Shevchenko <andy@xxxxxxxxxx> wrote: > > On Tue, Feb 18, 2025 at 07:11:33PM +0800, Binbin Zhou wrote: > > According to the chip manual, the I2C register access type of > > Loongson-2K2000/LS7A is "B", so we can only access registers in byte > > form (readb/writeb). > > > > Although Loongson-2K0500/Loongson-2K1000 do not have similar > > constraints, register accesses in byte form also behave correctly. > > > > Also, in hardware, the frequency division registers are defined as two > > separate registers (high 8-bit and low 8-bit), so we just access them > > directly as bytes. > > ... > > > /* Calculate and set i2c frequency. */ > > - writew(LS2X_I2C_PCLK_FREQ / (5 * t->bus_freq_hz) - 1, > > - priv->base + I2C_LS2X_PRER); > > + val = LS2X_I2C_PCLK_FREQ / (5 * t->bus_freq_hz) - 1; > > + writeb(FIELD_GET(GENMASK(7, 0), val), priv->base + I2C_LS2X_PRER_LO); > > + writeb(FIELD_GET(GENMASK(15, 8), val), priv->base + I2C_LS2X_PRER_HI); > > Now this needs a comment to prevent from appearing a patch that basically > changes that back to 16-bit write. I will add a commit here. > > -- > With Best Regards, > Andy Shevchenko > > > -- Thanks. Binbin
