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

From: Ian Abbott
Date: Wed Nov 18 2015 - 11:26:59 EST


On 14/11/15 17:10, Ranjith Thangavel wrote:
BIT macro is used for defining BIT location instead of
shifting operator, usleep_range is preferred over
udelay - coding style issue

Those two things should be done in separate patches.

Signed-off-by: Ranjith Thangavel <ranjithece24@xxxxxxxxx>
---
drivers/staging/comedi/drivers/dmm32at.c | 104 +++++++++++++++---------------
1 file changed, 52 insertions(+), 52 deletions(-)

diff --git a/drivers/staging/comedi/drivers/dmm32at.c b/drivers/staging/comedi/drivers/dmm32at.c
index 958c0d4..0836d39 100644
--- a/drivers/staging/comedi/drivers/dmm32at.c
+++ b/drivers/staging/comedi/drivers/dmm32at.c
@@ -46,74 +46,74 @@
#define DMM32AT_AI_START_CONV_REG 0x00
#define DMM32AT_AI_LSB_REG 0x00
#define DMM32AT_AUX_DOUT_REG 0x01
-#define DMM32AT_AUX_DOUT2 (1 << 2) /* J3.42 - OUT2 (OUT2EN) */
-#define DMM32AT_AUX_DOUT1 (1 << 1) /* J3.43 */
-#define DMM32AT_AUX_DOUT0 (1 << 0) /* J3.44 - OUT0 (OUT0EN) */
+#define DMM32AT_AUX_DOUT2 BIT(2) /* J3.42 - OUT2 (OUT2EN) */
+#define DMM32AT_AUX_DOUT1 BIT(1) /* J3.43 */
+#define DMM32AT_AUX_DOUT0 BIT(0) /* J3.44 - OUT0 (OUT0EN) */
#define DMM32AT_AI_MSB_REG 0x01
#define DMM32AT_AI_LO_CHAN_REG 0x02
#define DMM32AT_AI_HI_CHAN_REG 0x03
#define DMM32AT_AUX_DI_REG 0x04
-#define DMM32AT_AUX_DI_DACBUSY (1 << 7)
-#define DMM32AT_AUX_DI_CALBUSY (1 << 6)
-#define DMM32AT_AUX_DI3 (1 << 3) /* J3.45 - ADCLK (CLKSEL) */
-#define DMM32AT_AUX_DI2 (1 << 2) /* J3.46 - GATE12 (GT12EN) */
-#define DMM32AT_AUX_DI1 (1 << 1) /* J3.47 - GATE0 (GT0EN) */
-#define DMM32AT_AUX_DI0 (1 << 0) /* J3.48 - CLK0 (SRC0) */
+#define DMM32AT_AUX_DI_DACBUSY BIT(7)
+#define DMM32AT_AUX_DI_CALBUSY BIT(6)
+#define DMM32AT_AUX_DI3 BIT(3) /* J3.45 - ADCLK (CLKSEL) */
+#define DMM32AT_AUX_DI2 BIT(2) /* J3.46 - GATE12 (GT12EN) */
+#define DMM32AT_AUX_DI1 BIT(1) /* J3.47 - GATE0 (GT0EN) */
+#define DMM32AT_AUX_DI0 BIT(0) /* J3.48 - CLK0 (SRC0) */
#define DMM32AT_AO_LSB_REG 0x04
#define DMM32AT_AO_MSB_REG 0x05
#define DMM32AT_AO_MSB_DACH(x) ((x) << 6)
#define DMM32AT_FIFO_DEPTH_REG 0x06
#define DMM32AT_FIFO_CTRL_REG 0x07
-#define DMM32AT_FIFO_CTRL_FIFOEN (1 << 3)
-#define DMM32AT_FIFO_CTRL_SCANEN (1 << 2)
-#define DMM32AT_FIFO_CTRL_FIFORST (1 << 1)
+#define DMM32AT_FIFO_CTRL_FIFOEN BIT(3)
+#define DMM32AT_FIFO_CTRL_SCANEN BIT(2)
+#define DMM32AT_FIFO_CTRL_FIFORST BIT(1)
#define DMM32AT_FIFO_STATUS_REG 0x07
-#define DMM32AT_FIFO_STATUS_EF (1 << 7)
-#define DMM32AT_FIFO_STATUS_HF (1 << 6)
-#define DMM32AT_FIFO_STATUS_FF (1 << 5)
-#define DMM32AT_FIFO_STATUS_OVF (1 << 4)
-#define DMM32AT_FIFO_STATUS_FIFOEN (1 << 3)
-#define DMM32AT_FIFO_STATUS_SCANEN (1 << 2)
-#define DMM32AT_FIFO_STATUS_PAGE_MASK (3 << 0)
+#define DMM32AT_FIFO_STATUS_EF BIT(7)
+#define DMM32AT_FIFO_STATUS_HF BIT(6)
+#define DMM32AT_FIFO_STATUS_FF BIT(5)
+#define DMM32AT_FIFO_STATUS_OVF BIT(4)
+#define DMM32AT_FIFO_STATUS_FIFOEN BIT(3)
+#define DMM32AT_FIFO_STATUS_SCANEN BIT(2)
+#define DMM32AT_FIFO_STATUS_PAGE_MASK 0

As Dan Carpenter pointer out the new value of DMM32AT_FIFO_STATUS_PAGE_MASK is wrong (the old value was 3).

#define DMM32AT_CTRL_REG 0x08
-#define DMM32AT_CTRL_RESETA (1 << 5)
-#define DMM32AT_CTRL_RESETD (1 << 4)
-#define DMM32AT_CTRL_INTRST (1 << 3)
-#define DMM32AT_CTRL_PAGE_8254 (0 << 0)
-#define DMM32AT_CTRL_PAGE_8255 (1 << 0)
-#define DMM32AT_CTRL_PAGE_CALIB (3 << 0)
+#define DMM32AT_CTRL_RESETA BIT(5)
+#define DMM32AT_CTRL_RESETD BIT(4)
+#define DMM32AT_CTRL_INTRST BIT(3)
+#define DMM32AT_CTRL_PAGE_8254 0
+#define DMM32AT_CTRL_PAGE_8255 BIT(0)
+#define DMM32AT_CTRL_PAGE_CALIB 0

The new value of DMM32AT_CTRL_PAGE_CALIB is wrong - the old value is 3. DMM32AT_CTRL_PAGE_8254, DMM32AT_CTRL_PAGE_8255 and DMM32AT_CTRL_PAGE_CALIB are 2-bit values, so the BIT() macro isn't really the best representation.

(To be honest, I don't really know what the preferred representation of shifted multi-bit values is.)

#define DMM32AT_AI_STATUS_REG 0x08
-#define DMM32AT_AI_STATUS_STS (1 << 7)
-#define DMM32AT_AI_STATUS_SD1 (1 << 6)
-#define DMM32AT_AI_STATUS_SD0 (1 << 5)
+#define DMM32AT_AI_STATUS_STS BIT(7)
+#define DMM32AT_AI_STATUS_SD1 BIT(6)
+#define DMM32AT_AI_STATUS_SD0 BIT(5)
#define DMM32AT_AI_STATUS_ADCH_MASK (0x1f << 0)
#define DMM32AT_INTCLK_REG 0x09
-#define DMM32AT_INTCLK_ADINT (1 << 7)
-#define DMM32AT_INTCLK_DINT (1 << 6)
-#define DMM32AT_INTCLK_TINT (1 << 5)
-#define DMM32AT_INTCLK_CLKEN (1 << 1) /* 1=see below 0=software */
-#define DMM32AT_INTCLK_CLKSEL (1 << 0) /* 1=OUT2 0=EXTCLK */
+#define DMM32AT_INTCLK_ADINT BIT(7)
+#define DMM32AT_INTCLK_DINT BIT(6)
+#define DMM32AT_INTCLK_TINT BIT(5)
+#define DMM32AT_INTCLK_CLKEN BIT(1) /* 1=see below 0=software */
+#define DMM32AT_INTCLK_CLKSEL BIT(0) /* 1=OUT2 0=EXTCLK */
#define DMM32AT_CTRDIO_CFG_REG 0x0a
-#define DMM32AT_CTRDIO_CFG_FREQ12 (1 << 7) /* CLK12 1=100KHz 0=10MHz */
-#define DMM32AT_CTRDIO_CFG_FREQ0 (1 << 6) /* CLK0 1=10KHz 0=10MHz */
-#define DMM32AT_CTRDIO_CFG_OUT2EN (1 << 5) /* J3.42 1=OUT2 is DOUT2 */
-#define DMM32AT_CTRDIO_CFG_OUT0EN (1 << 4) /* J3,44 1=OUT0 is DOUT0 */
-#define DMM32AT_CTRDIO_CFG_GT0EN (1 << 2) /* J3.47 1=DIN1 is GATE0 */
-#define DMM32AT_CTRDIO_CFG_SRC0 (1 << 1) /* CLK0 is 0=FREQ0 1=J3.48 */
-#define DMM32AT_CTRDIO_CFG_GT12EN (1 << 0) /* J3.46 1=DIN2 is GATE12 */
+#define DMM32AT_CTRDIO_CFG_FREQ12 BIT(7) /* CLK12 1=100KHz 0=10MHz */
+#define DMM32AT_CTRDIO_CFG_FREQ0 BIT(6) /* CLK0 1=10KHz 0=10MHz */
+#define DMM32AT_CTRDIO_CFG_OUT2EN BIT(5) /* J3.42 1=OUT2 is DOUT2 */
+#define DMM32AT_CTRDIO_CFG_OUT0EN BIT(4) /* J3,44 1=OUT0 is DOUT0 */
+#define DMM32AT_CTRDIO_CFG_GT0EN BIT(2) /* J3.47 1=DIN1 is GATE0 */
+#define DMM32AT_CTRDIO_CFG_SRC0 BIT(1) /* CLK0 is 0=FREQ0 1=J3.48 */
+#define DMM32AT_CTRDIO_CFG_GT12EN BIT(0) /* J3.46 1=DIN2 is GATE12 */
#define DMM32AT_AI_CFG_REG 0x0b
-#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))
+#define DMM32AT_AI_CFG_SCINT_5US (BIT(5) | BIT(4))

The values of DMM32AT_AI_CFG_SCINT_20US etc. are numerically correct, but look a bit strange. The `(BIT(5) & ~BIT(4))` looks especially strange and could be changed to `BIT(5)`. These are all really shifted 2-bit values, so perhaps the BIT() macro isn't the best representation.

+#define DMM32AT_AI_CFG_RANGE BIT(3) /* 0=5V 1=10V */
+#define DMM32AT_AI_CFG_ADBU BIT(2) /* 0=bipolar 1=unipolar */
#define DMM32AT_AI_CFG_GAIN(x) ((x) << 0)
#define DMM32AT_AI_READBACK_REG 0x0b
-#define DMM32AT_AI_READBACK_WAIT (1 << 7) /* DMM32AT_AI_STATUS_STS */
-#define DMM32AT_AI_READBACK_RANGE (1 << 3)
-#define DMM32AT_AI_READBACK_ADBU (1 << 2)
-#define DMM32AT_AI_READBACK_GAIN_MASK (3 << 0)
+#define DMM32AT_AI_READBACK_WAIT BIT(7) /* DMM32AT_AI_STATUS_STS */
+#define DMM32AT_AI_READBACK_RANGE BIT(3)
+#define DMM32AT_AI_READBACK_ADBU BIT(2)
+#define DMM32AT_AI_READBACK_GAIN_MASK 0

The value of DMM32AT_AI_READBACK_GAIN_MASK is wrong - the old value was 3.


#define DMM32AT_CLK1 0x0d
#define DMM32AT_CLK2 0x0e
@@ -508,7 +508,7 @@ static int dmm32at_reset(struct comedi_device *dev)
outb(DMM32AT_CTRL_RESETA, dev->iobase + DMM32AT_CTRL_REG);

/* allow a millisecond to reset */
- udelay(1000);
+ usleep_range(1000, 1050);

/* zero scan and fifo control */
outb(0x0, dev->iobase + DMM32AT_FIFO_CTRL_REG);
@@ -524,7 +524,7 @@ static int dmm32at_reset(struct comedi_device *dev)
outb(DMM32AT_RANGE_U10, dev->iobase + DMM32AT_AI_CFG_REG);

/* should take 10 us to settle, here's a hundred */
- udelay(100);
+ usleep_range(100, 150);

/* read back the values */
ailo = inb(dev->iobase + DMM32AT_AI_LO_CHAN_REG);


The usleep_range() stuff is unrelated to the use of the BIT() macro and should be in a separate patch.

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