diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-rk3x.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-rk3x.c | 11 |
1 files changed, 5 insertions, 6 deletions
diff --git a/drivers/i2c/busses/i2c-rk3x.c b/drivers/i2c/busses/i2c-rk3x.c index e637c32ae517..93cfc837200b 100644 --- a/drivers/i2c/busses/i2c-rk3x.c +++ b/drivers/i2c/busses/i2c-rk3x.c @@ -433,12 +433,11 @@ static void rk3x_i2c_set_scl_rate(struct rk3x_i2c *i2c, unsigned long scl_rate) unsigned long i2c_rate = clk_get_rate(i2c->clk); unsigned int div; - /* SCL rate = (clk rate) / (8 * DIV) */ - div = DIV_ROUND_UP(i2c_rate, scl_rate * 8); - - /* The lower and upper half of the CLKDIV reg describe the length of - * SCL low & high periods. */ - div = DIV_ROUND_UP(div, 2); + /* set DIV = DIVH = DIVL + * SCL rate = (clk rate) / (8 * (DIVH + 1 + DIVL + 1)) + * = (clk rate) / (16 * (DIV + 1)) + */ + div = DIV_ROUND_UP(i2c_rate, scl_rate * 16) - 1; i2c_writel(i2c, (div << 16) | (div & 0xffff), REG_CLKDIV); } |