diff --git a/drivers/i2c/busses/i2c-bcm2835.c b/drivers/i2c/busses/i2c-bcm2835.c index 59c1dbd67f7a8..dcedc73209ea8 100644 --- a/drivers/i2c/busses/i2c-bcm2835.c +++ b/drivers/i2c/busses/i2c-bcm2835.c @@ -193,6 +193,7 @@ static int clk_bcm2835_i2c_set_rate(struct clk_hw *hw, unsigned long rate, { struct clk_bcm2835_i2c *div = to_clk_bcm2835_i2c(hw); u32 redl, fedl; + u32 clk_tout; u32 divider = clk_bcm2835_i2c_calc_divider(rate, parent_rate); if (divider == -EINVAL) @@ -216,6 +217,17 @@ static int clk_bcm2835_i2c_set_rate(struct clk_hw *hw, unsigned long rate, bcm2835_i2c_writel(div->i2c_dev, BCM2835_I2C_DEL, (fedl << BCM2835_I2C_FEDL_SHIFT) | (redl << BCM2835_I2C_REDL_SHIFT)); + + /* + * Set the clock stretch timeout to the SMBUs-recommended 35ms. + */ + if (rate > 0xffff*1000/35) + clk_tout = 0xffff; + else + clk_tout = 35*rate/1000; + + bcm2835_i2c_writel(div->i2c_dev, BCM2835_I2C_CLKT, clk_tout); + return 0; }