Re: [PATCH 07/50] staging: omap-thermal: introduce RMW_BITS macro

2013-03-16 Thread Eduardo Valentin

Hello Dan,

On 15-03-2013 17:09, Dan Carpenter wrote:

On Fri, Mar 15, 2013 at 08:59:55AM -0400, Eduardo Valentin wrote:

This patch introduce a macro to read, update, write bitfields.
It will be specific to bandgap data structures.

Signed-off-by: Eduardo Valentin eduardo.valen...@ti.com
---
  drivers/staging/omap-thermal/omap-bandgap.c |  178 +++
  1 files changed, 46 insertions(+), 132 deletions(-)

diff --git a/drivers/staging/omap-thermal/omap-bandgap.c 
b/drivers/staging/omap-thermal/omap-bandgap.c
index 9f2d7cc..1c1b905 100644
--- a/drivers/staging/omap-thermal/omap-bandgap.c
+++ b/drivers/staging/omap-thermal/omap-bandgap.c
@@ -52,25 +52,29 @@ static void omap_bandgap_writel(struct omap_bandgap 
*bg_ptr, u32 val, u32 reg)
writel(val, bg_ptr-base + reg);
  }

+/* update bits, value will be shifted */
+#define RMW_BITS(bg_ptr, id, reg, mask, val)   \
+do {   \
+   struct temp_sensor_registers *t;\
+   u32 r;  \
+   \
+   t = bg_ptr-conf-sensors[(id)].registers;\
+   r = omap_bandgap_readl(bg_ptr, t-reg);  \
+   r = ~t-mask;   \
+   r |= (val)  __ffs(t-mask);  \
+   omap_bandgap_writel(bg_ptr, r, t-reg);  \
+} while (0)
+
  static int omap_bandgap_power(struct omap_bandgap *bg_ptr, bool on)
  {
-   struct temp_sensor_registers *tsr;
int i;
-   u32 ctrl;

if (!OMAP_BANDGAP_HAS(bg_ptr, POWER_SWITCH))
return 0;

-   for (i = 0; i  bg_ptr-conf-sensor_count; i++) {
-   tsr = bg_ptr-conf-sensors[i].registers;
-   ctrl = omap_bandgap_readl(bg_ptr, tsr-temp_sensor_ctrl);
-   ctrl = ~tsr-bgap_tempsoff_mask;
+   for (i = 0; i  bg_ptr-conf-sensor_count; i++)
/* active on 0 */
-   ctrl |= !on  __ffs(tsr-bgap_tempsoff_mask);
-
-   /* write BGAP_TEMPSOFF should be reset to 0 */
-   omap_bandgap_writel(bg_ptr, ctrl, tsr-temp_sensor_ctrl);
-   }
+   RMW_BITS(bg_ptr, i, temp_sensor_ctrl, bgap_tempsoff_mask, !on);

return 0;
  }
@@ -78,15 +82,13 @@ static int omap_bandgap_power(struct omap_bandgap *bg_ptr, 
bool on)
  static u32 omap_bandgap_read_temp(struct omap_bandgap *bg_ptr, int id)
  {


This patch is fine and it makes it cleaner than before.

But that said, I don't care for the RMW_BITS() very much as a long
term thing.  If we just used pointers instead of passing the offset
into the bg_ptr-conf-sensors[] array then everything would be a
lot cleaner.

In other words, instead of this:

static u32 omap_bandgap_read_temp(struct omap_bandgap *bg_ptr, int id)

We would have:

static u32 omap_bandgap_read_temp(struct omap_bandgap *bg_ptr,
  struct temp_sensor_registers *tsr)


I see. That will require a change in the whole driver though. If you 
see, the driver as of today uses the former approach, not only for 
read_temp or rmw_bits.




If you have the pointer then it's easy write RMW_BITS() as a
function.

static void rmw_bits(struct omap_bandgap *bg_ptr, u32 reg, u32 mask, u32 val)
{
u32 r;

r = omap_bandgap_readl(bg_ptr, reg);
r = ~mask;
r |= val  __ffs(mask);
omap_bandgap_writel(bg_ptr, r, reg);
}

It's called like:

rmw_bits(bg_ptr, tsr-bgap_mask_ctrl, tsr-mask_freeze_mask, 1);


This is nice, but it will require fetching tsr from .conf before every 
call o rmw_bits. And for that you need the sensor index.




regards,
dan carpenter


Thanks for your time reviewing this patch and suggesting improvements.








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Re: [PATCH 07/50] staging: omap-thermal: introduce RMW_BITS macro

2013-03-16 Thread Dan Carpenter
On Sat, Mar 16, 2013 at 08:36:51AM -0400, Eduardo Valentin wrote:
 But that said, I don't care for the RMW_BITS() very much as a long
 term thing.  If we just used pointers instead of passing the offset
 into the bg_ptr-conf-sensors[] array then everything would be a
 lot cleaner.
 
 In other words, instead of this:
 
 static u32 omap_bandgap_read_temp(struct omap_bandgap *bg_ptr, int id)
 
 We would have:
 
 static u32 omap_bandgap_read_temp(struct omap_bandgap *bg_ptr,
struct temp_sensor_registers *tsr)
 
 I see. That will require a change in the whole driver though. If you
 see, the driver as of today uses the former approach, not only for
 read_temp or rmw_bits.

Yep.

 
 
 If you have the pointer then it's easy write RMW_BITS() as a
 function.
 
 static void rmw_bits(struct omap_bandgap *bg_ptr, u32 reg, u32 mask, u32 val)
 {
  u32 r;
 
  r = omap_bandgap_readl(bg_ptr, reg);
  r = ~mask;
  r |= val  __ffs(mask);
  omap_bandgap_writel(bg_ptr, r, reg);
 }
 
 It's called like:
 
  rmw_bits(bg_ptr, tsr-bgap_mask_ctrl, tsr-mask_freeze_mask, 1);
 
 This is nice, but it will require fetching tsr from .conf before
 every call o rmw_bits. And for that you need the sensor index.
 

No.  I'm suggesting that you re-write the driver to pass the tsr
pointer directly instead of the index.

regards,
dan carpenter

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Re: [PATCH 07/50] staging: omap-thermal: introduce RMW_BITS macro

2013-03-15 Thread Dan Carpenter
On Fri, Mar 15, 2013 at 08:59:55AM -0400, Eduardo Valentin wrote:
 This patch introduce a macro to read, update, write bitfields.
 It will be specific to bandgap data structures.
 
 Signed-off-by: Eduardo Valentin eduardo.valen...@ti.com
 ---
  drivers/staging/omap-thermal/omap-bandgap.c |  178 
 +++
  1 files changed, 46 insertions(+), 132 deletions(-)
 
 diff --git a/drivers/staging/omap-thermal/omap-bandgap.c 
 b/drivers/staging/omap-thermal/omap-bandgap.c
 index 9f2d7cc..1c1b905 100644
 --- a/drivers/staging/omap-thermal/omap-bandgap.c
 +++ b/drivers/staging/omap-thermal/omap-bandgap.c
 @@ -52,25 +52,29 @@ static void omap_bandgap_writel(struct omap_bandgap 
 *bg_ptr, u32 val, u32 reg)
   writel(val, bg_ptr-base + reg);
  }
  
 +/* update bits, value will be shifted */
 +#define RMW_BITS(bg_ptr, id, reg, mask, val) \
 +do { \
 + struct temp_sensor_registers *t;\
 + u32 r;  \
 + \
 + t = bg_ptr-conf-sensors[(id)].registers;  \
 + r = omap_bandgap_readl(bg_ptr, t-reg); \
 + r = ~t-mask;  \
 + r |= (val)  __ffs(t-mask);   \
 + omap_bandgap_writel(bg_ptr, r, t-reg); \
 +} while (0)
 +
  static int omap_bandgap_power(struct omap_bandgap *bg_ptr, bool on)
  {
 - struct temp_sensor_registers *tsr;
   int i;
 - u32 ctrl;
  
   if (!OMAP_BANDGAP_HAS(bg_ptr, POWER_SWITCH))
   return 0;
  
 - for (i = 0; i  bg_ptr-conf-sensor_count; i++) {
 - tsr = bg_ptr-conf-sensors[i].registers;
 - ctrl = omap_bandgap_readl(bg_ptr, tsr-temp_sensor_ctrl);
 - ctrl = ~tsr-bgap_tempsoff_mask;
 + for (i = 0; i  bg_ptr-conf-sensor_count; i++)
   /* active on 0 */
 - ctrl |= !on  __ffs(tsr-bgap_tempsoff_mask);
 -
 - /* write BGAP_TEMPSOFF should be reset to 0 */
 - omap_bandgap_writel(bg_ptr, ctrl, tsr-temp_sensor_ctrl);
 - }
 + RMW_BITS(bg_ptr, i, temp_sensor_ctrl, bgap_tempsoff_mask, !on);
  
   return 0;
  }
 @@ -78,15 +82,13 @@ static int omap_bandgap_power(struct omap_bandgap 
 *bg_ptr, bool on)
  static u32 omap_bandgap_read_temp(struct omap_bandgap *bg_ptr, int id)
  {

This patch is fine and it makes it cleaner than before.

But that said, I don't care for the RMW_BITS() very much as a long
term thing.  If we just used pointers instead of passing the offset
into the bg_ptr-conf-sensors[] array then everything would be a
lot cleaner.

In other words, instead of this:

static u32 omap_bandgap_read_temp(struct omap_bandgap *bg_ptr, int id)

We would have:

static u32 omap_bandgap_read_temp(struct omap_bandgap *bg_ptr,
  struct temp_sensor_registers *tsr)

If you have the pointer then it's easy write RMW_BITS() as a
function.

static void rmw_bits(struct omap_bandgap *bg_ptr, u32 reg, u32 mask, u32 val)
{
u32 r;

r = omap_bandgap_readl(bg_ptr, reg);
r = ~mask;
r |= val  __ffs(mask);
omap_bandgap_writel(bg_ptr, r, reg);
}

It's called like:

rmw_bits(bg_ptr, tsr-bgap_mask_ctrl, tsr-mask_freeze_mask, 1);

regards,
dan carpenter


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