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.valentin@xxxxxx>
---
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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