OpenE2K/linux
6
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

i2c: omap: simplify omap_i2c_ack_stat()

Browse Source 
stat & BIT(1) is the same as BIT(1), so let's
simplify things a bit by removing "stat &" from
all omap_i2c_ack_stat() calls.

Code snippet (extremely simplified):

if (stat & NACK) {
        ...
        omap_i2c_ack_stat(dev, stat & NACK);
}

if (stat & RDR) {
        ...
        omap_i2c_ack_stat(dev, stat & RDR);
}

and so on. The tricky place is only WRT errata handling, for example:

if (*stat & (NACK | AL)) {
        omap_i2c_ack_stat(dev, *stat & (XRDY | XDR));
        ...
}

but in this case, the errata says we must clear XRDY and XDR if that
errata triggers, so if they just got enabled or not, it doesn't matter.

Another tricky place is RDR | RRDY (likewise for XDR | XRDY):

if (stat & (RDR | RRDY)) {
        ...
        omap_i2c_ack_stat(dev, stat & (RDR | RRDY));
}

again here there will be no issues because those IRQs never fire
simultaneously and one will only after after we have handled the
previous, that's because the same FIFO is used anyway and we won't shift
data into FIFO until we tell the IP "hey, I'm done with the FIFO, you
can shift more data"

Signed-off-by: Felipe Balbi <balbi@ti.com>
Reviewed-by : Santosh Shilimkar <santosh.shilimkar@ti.com>
[Added the explaination from the discurssion to the commit logs]
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
This commit is contained in:
Felipe Balbi 2012-09-12 16:27:59 +05:30 committed by Wolfram Sang
parent c55edb9902
commit 540a4790f7
1 changed files with 10 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
drivers/i2c/busses/i2c-omap.c
View File

@ -731,7 +731,7 @@ static int errata_omap3_i462(struct omap_i2c_dev *dev, u16 *stat, int *err)
while (--timeout && !(*stat & OMAP_I2C_STAT_XUDF)) {
if (*stat & (OMAP_I2C_STAT_NACK | OMAP_I2C_STAT_AL)) {
omap_i2c_ack_stat(dev, *stat & (OMAP_I2C_STAT_XRDY |
omap_i2c_ack_stat(dev, (OMAP_I2C_STAT_XRDY |
OMAP_I2C_STAT_XDR));
return -ETIMEDOUT;
}
@ -792,10 +792,11 @@ complete:
*/
if (stat & (OMAP_I2C_STAT_ARDY | OMAP_I2C_STAT_NACK |
OMAP_I2C_STAT_AL)) {
omap_i2c_ack_stat(dev, stat &
(OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR |
OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR |
OMAP_I2C_STAT_ARDY));
omap_i2c_ack_stat(dev, (OMAP_I2C_STAT_RRDY |
OMAP_I2C_STAT_RDR |
OMAP_I2C_STAT_XRDY |
OMAP_I2C_STAT_XDR |
OMAP_I2C_STAT_ARDY));
omap_i2c_complete_cmd(dev, err);
return IRQ_HANDLED;
}
@ -842,8 +843,8 @@ complete:
}
}
}
omap_i2c_ack_stat(dev,
stat & (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR));
omap_i2c_ack_stat(dev, (OMAP_I2C_STAT_RRDY |
OMAP_I2C_STAT_RDR));
continue;
}
@ -890,8 +891,8 @@ complete:
omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);
}
omap_i2c_ack_stat(dev,
stat & (OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR));
omap_i2c_ack_stat(dev, (OMAP_I2C_STAT_XRDY |
OMAP_I2C_STAT_XDR));
continue;
}