On 19/06/2025 12:15, Paolo Abeni wrote:
On 6/16/25 10:14 PM, Ivan Vecera wrote:+/** + * zl3073x_dpll_input_ref_frequency_get - get input reference frequency + * @zldpll: pointer to zl3073x_dpll + * @ref_id: reference id + * @frequency: pointer to variable to store frequency + * + * Reads frequency of given input reference. + * + * Return: 0 on success, <0 on error + */ +static int +zl3073x_dpll_input_ref_frequency_get(struct zl3073x_dpll *zldpll, u8 ref_id, + u32 *frequency) +{ + struct zl3073x_dev *zldev = zldpll->dev; + u16 base, mult, num, denom; + int rc; + + guard(mutex)(&zldev->multiop_lock); + + /* Read reference configuration */ + rc = zl3073x_mb_op(zldev, ZL_REG_REF_MB_SEM, ZL_REF_MB_SEM_RD, + ZL_REG_REF_MB_MASK, BIT(ref_id)); + if (rc) + return rc; + + /* Read registers to compute resulting frequency */ + rc = zl3073x_read_u16(zldev, ZL_REG_REF_FREQ_BASE, &base); + if (rc) + return rc; + rc = zl3073x_read_u16(zldev, ZL_REG_REF_FREQ_MULT, &mult); + if (rc) + return rc; + rc = zl3073x_read_u16(zldev, ZL_REG_REF_RATIO_M, &num); + if (rc) + return rc; + rc = zl3073x_read_u16(zldev, ZL_REG_REF_RATIO_N, &denom); + if (rc) + return rc; + + /* Sanity check that HW has not returned zero denominator */ + if (!denom) { + dev_err(zldev->dev, + "Zero divisor for ref %u frequency got from device\n", + ref_id); + return -EINVAL; + } + + /* Compute the frequency */ + *frequency = base * mult * num / denom;As base, mult, num and denom are u16, the above looks like integer overflow prone. I think you should explicitly cast to u64, and possibly use a u64 frequency.
I might be a good idea to use mul_u64_u32_div together with mul_u32_u32? These macroses will take care of overflow on 32bit platforms as well.
/P
