On 1/4/23 11:32, Alexander Stein wrote:
Hi Marek,
Hi,
Am Dienstag, 3. Januar 2023, 15:31:21 CET schrieb Marek Vasut:
On 1/3/23 13:31, Alexander Stein wrote:
The calculation DIFx is BIT(n) +1 is only true for 9FGV0241. With
additional devices this is getting more complicated.
Support a base bit for the DIF calculation, currently only devices
with consecutive bits are supported, e.g. the 6-channel device needs
additional logic.
Signed-off-by: Alexander Stein <alexander.stein@xxxxxxxxxxxxxxx>
---
drivers/clk/clk-renesas-pcie.c | 29 ++++++++++++++++-------------
1 file changed, 16 insertions(+), 13 deletions(-)
diff --git a/drivers/clk/clk-renesas-pcie.c
b/drivers/clk/clk-renesas-pcie.c index 0076ed8f11b0..d19b8e759eea 100644
--- a/drivers/clk/clk-renesas-pcie.c
+++ b/drivers/clk/clk-renesas-pcie.c
@@ -18,7 +18,6 @@
#include <linux/regmap.h>
#define RS9_REG_OE 0x0
-#define RS9_REG_OE_DIF_OE(n) BIT((n) + 1)
#define RS9_REG_SS 0x1
#define RS9_REG_SS_AMP_0V6 0x0
#define RS9_REG_SS_AMP_0V7 0x1
@@ -31,9 +30,6 @@
#define RS9_REG_SS_SSC_MASK (3 << 3)
#define RS9_REG_SS_SSC_LOCK BIT(5)
#define RS9_REG_SR 0x2
-#define RS9_REG_SR_2V0_DIF(n) 0
-#define RS9_REG_SR_3V0_DIF(n) BIT((n) + 1)
-#define RS9_REG_SR_DIF_MASK(n) BIT((n) + 1)
#define RS9_REG_REF 0x3
#define RS9_REG_REF_OE BIT(4)
#define RS9_REG_REF_OD BIT(5)
@@ -62,6 +58,7 @@ struct rs9_chip_info {
const enum rs9_model model;
unsigned int num_clks;
u8 did;
+ u8 (*calc_dif)(int idx);
};
struct rs9_driver_data {
@@ -160,8 +157,14 @@ static const struct regmap_config rs9_regmap_config =
{>
.reg_read = rs9_regmap_i2c_read,
};
+static u8 rs9fgv0241_calc_dif(int idx)
+{
+ return BIT(idx) + 1;
Can't we just do
if (model == ...)
return BIT(idx) + 1
else if (model == ...)
return BIT(idx);
...
I was tempted going this way. But I opted for a callback due to the fact that
this driver might support 9FGV/9DBV/9DMV/9FGL/9DML/9QXL/9SQ as well(your
comment in the header).
Even just considering 9FVG, 9FGV0641 has an even more complex DIF offset
calculation.
The mapping is
* DIF OE0 - Bit 0
* DIF OE1 - Bit 2
* DIF OE2 - Bit 3
* DIF OE3 - Bit 4
* DIF OE4 - Bit 6
* DIF OE5 - Bit 7
So the calucation might not fit into one line, so the readability benefit is
gone.
You can still do
if (model == ...)
return function1();
else if (model == ...)
return function2();
which would work without any indirection via callback.
