[PATCH] staging: sm750fb: Simplify M2XCLK divisor encoding
From: himanshu bakshi
Date: Sun Oct 18 2026 - 05:27:13 EST
Replace the switch statement with a macro to encode the M2XCLK
divisor in the corresponding register bits.
This is my first Linux kernel patch.
Signed-off-by: himanshu bakshi <himanshu.bakshi478@xxxxxxxxx>
---
drivers/staging/sm750fb/ddk750_chip.c | 18 +++---------------
drivers/staging/sm750fb/ddk750_reg.h | 5 +----
2 files changed, 4 insertions(+), 19 deletions(-)
diff --git a/drivers/staging/sm750fb/ddk750_chip.c b/drivers/staging/sm750fb/ddk750_chip.c
index aa78d0bc1..2cb849dea 100644
--- a/drivers/staging/sm750fb/ddk750_chip.c
+++ b/drivers/staging/sm750fb/ddk750_chip.c
@@ -109,21 +109,9 @@ static void set_memory_clock(unsigned int frequency)
/* Set the corresponding divisor in the register. */
reg = peek32(CURRENT_GATE) & ~CURRENT_GATE_M2XCLK_MASK;
- switch (divisor) {
- default:
- case 1:
- reg |= CURRENT_GATE_M2XCLK_DIV_1;
- break;
- case 2:
- reg |= CURRENT_GATE_M2XCLK_DIV_2;
- break;
- case 3:
- reg |= CURRENT_GATE_M2XCLK_DIV_3;
- break;
- case 4:
- reg |= CURRENT_GATE_M2XCLK_DIV_4;
- break;
- }
+ if (divisor == 0 || divisor > 4)
+ divisor = 1;
+ reg |= CURRENT_GATE_M2XCLK_DIV(divisor);
sm750_set_current_gate(reg);
}
diff --git a/drivers/staging/sm750fb/ddk750_reg.h b/drivers/staging/sm750fb/ddk750_reg.h
index fe412ead7..b796e32ab 100644
--- a/drivers/staging/sm750fb/ddk750_reg.h
+++ b/drivers/staging/sm750fb/ddk750_reg.h
@@ -312,10 +312,7 @@
#define CURRENT_GATE_M2XCLK_112MHZ (0x2 << 12)
#define CURRENT_GATE_M2XCLK_84MHZ (0x3 << 12)
#else
- #define CURRENT_GATE_M2XCLK_DIV_1 (0x0 << 12)
- #define CURRENT_GATE_M2XCLK_DIV_2 (0x1 << 12)
- #define CURRENT_GATE_M2XCLK_DIV_3 (0x2 << 12)
- #define CURRENT_GATE_M2XCLK_DIV_4 (0x3 << 12)
+ #define CURRENT_GATE_M2XCLK_DIV(divisor) (((divisor) - 1) << 12)
#endif
#define CURRENT_GATE_VGA BIT(10)
#define CURRENT_GATE_PWM BIT(9)
--
2.56.0