On 03/23/2016 06:46 AM, Stefan Roese wrote:
dw_i2c_enable() is used to dis-/en-able the I2C controller. It makes sense to add such a function, as the controller is dis-/en-abled multiple times in the code. Additionally, this function now checks, if the controller is really dis-/en-abled. This code is copied from the Linux I2C driver version.
Signed-off-by: Stefan Roese sr@denx.de Cc: Simon Glass sjg@chromium.org Cc: Bin Meng bmeng.cn@gmail.com Cc: Marek Vasut marex@denx.de Cc: Heiko Schocher hs@denx.de
v2:
- Use true / false for binary values as suggested by Bin
drivers/i2c/designware_i2c.c | 46 +++++++++++++++++++++++++------------------- 1 file changed, 26 insertions(+), 20 deletions(-)
diff --git a/drivers/i2c/designware_i2c.c b/drivers/i2c/designware_i2c.c index e768cde..2b0c8cb 100644 --- a/drivers/i2c/designware_i2c.c +++ b/drivers/i2c/designware_i2c.c @@ -34,6 +34,26 @@ static struct i2c_regs *i2c_get_base(struct i2c_adapter *adap) return NULL; }
+static void dw_i2c_enable(struct i2c_regs *i2c_base, bool enable) +{
- int timeout = 100;
- do {
writel(enable, &i2c_base->ic_enable);
I believe boolean true in C can be anything non-zero, not necessarily one (1). It is safer to be explicit and do enable = enable ? IC_ENABLE_0B : 0; at the beginning of the function
if ((readl(&i2c_base->ic_enable_status) & 1) == enable)
Also drop this & 1 and make it IC_ENABLE_0B please.
return;/** Wait 10 times the signaling period of the highest I2C* transfer supported by the driver (for 400KHz this is* 25us) as described in the DesignWare I2C databook.*/udelay(25);- } while (timeout--);
It's a shame we cannot flip this to wait_for_bit() :(
- printf("timeout in %sabling I2C adapter\n", enable ? "en" : "dis");
+}
[..] Best regards, Marek Vasut