Re: [PATCH 1/2] comedi: dmm32at: Fix coding style - use BIT macro

From: Ian Abbott
Date: Wed Nov 18 2015 - 11:42:06 EST


On 16/11/15 17:18, Ranjith Thangavel wrote:
BIT macro is used for defining BIT location instead of
shifting operator, usleep_range is preferred over
udelay - coding style issue

This patch doesn't use usleep_range(), so the description is inaccurate.


Signed-off-by: Ranjith Thangavel <ranjithece24@xxxxxxxxx>
---
drivers/staging/comedi/drivers/dmm32at.c | 100 +++++++++++++++---------------
1 file changed, 50 insertions(+), 50 deletions(-)

diff --git a/drivers/staging/comedi/drivers/dmm32at.c b/drivers/staging/comedi/drivers/dmm32at.c
index 958c0d4..d312fda 100644
--- a/drivers/staging/comedi/drivers/dmm32at.c
+++ b/drivers/staging/comedi/drivers/dmm32at.c
[snip]
-#define DMM32AT_AI_CFG_SCINT_20US (0 << 4)
-#define DMM32AT_AI_CFG_SCINT_15US (1 << 4)
-#define DMM32AT_AI_CFG_SCINT_10US (2 << 4)
-#define DMM32AT_AI_CFG_SCINT_5US (3 << 4)
-#define DMM32AT_AI_CFG_RANGE (1 << 3) /* 0=5V 1=10V */
-#define DMM32AT_AI_CFG_ADBU (1 << 2) /* 0=bipolar 1=unipolar */
+#define DMM32AT_AI_CFG_SCINT_20US 0
+#define DMM32AT_AI_CFG_SCINT_15US BIT(4)
+#define DMM32AT_AI_CFG_SCINT_10US (BIT(5) & ~BIT(4))

The `(BIT(5) & ~BIT(4))` is a bit ugly. You can just use `BIT(5)` to fit in with the style of your other changes.

(Personally though, I don't think BIT() is appropriate for shifted, multi-bit values.)

+#define DMM32AT_AI_CFG_SCINT_5US (BIT(5) | BIT(4))
+#define DMM32AT_AI_CFG_RANGE BIT(3) /* 0=5V 1=10V */
+#define DMM32AT_AI_CFG_ADBU BIT(2) /* 0=bipolar 1=unipolar */
[snip]

--
-=( Ian Abbott @ MEV Ltd. E-mail: <abbotti@xxxxxxxxx> )=-
-=( Web: http://www.mev.co.uk/ )=-
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