[PATCH v4 4/5] i3c: mipi-i3c-hci: use parity8 helper instead of open coding it

[Wolfram Sang <wsa+renesas@sang-engineering.com>]

The kernel has now a generic helper for getting parity with easier to
understand semantics. Make use of it. Here, it also fixes a bug because
the correct algorithm is using XOR ('^=') instead of ADD ('+=').

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
---

Change since v3:

* updated commit message to mention the bugfix

I intentionally did not add a Fixes tag because this fix depends on
patch 1. The proper fix for backporting would change this to XOR, I'd
think.

 drivers/i3c/master/mipi-i3c-hci/dat_v1.c | 11 +----------
 1 file changed, 1 insertion(+), 10 deletions(-)

diff --git a/drivers/i3c/master/mipi-i3c-hci/dat_v1.c b/drivers/i3c/master/mipi-i3c-hci/dat_v1.c
index 47b9b4d4ed3f..85c4916972e4 100644
--- a/drivers/i3c/master/mipi-i3c-hci/dat_v1.c
+++ b/drivers/i3c/master/mipi-i3c-hci/dat_v1.c
@@ -40,15 +40,6 @@
 #define dat_w0_write(i, v)	writel(v, hci->DAT_regs + (i) * 8)
 #define dat_w1_write(i, v)	writel(v, hci->DAT_regs + (i) * 8 + 4)
 
-static inline bool dynaddr_parity(unsigned int addr)
-{
-	addr |= 1 << 7;
-	addr += addr >> 4;
-	addr += addr >> 2;
-	addr += addr >> 1;
-	return (addr & 1);
-}
-
 static int hci_dat_v1_init(struct i3c_hci *hci)
 {
 	unsigned int dat_idx;
@@ -123,7 +114,7 @@ static void hci_dat_v1_set_dynamic_addr(struct i3c_hci *hci,
 	dat_w0 = dat_w0_read(dat_idx);
 	dat_w0 &= ~(DAT_0_DYNAMIC_ADDRESS | DAT_0_DYNADDR_PARITY);
 	dat_w0 |= FIELD_PREP(DAT_0_DYNAMIC_ADDRESS, address) |
-		  (dynaddr_parity(address) ? DAT_0_DYNADDR_PARITY : 0);
+		  (parity8(address) ? 0 : DAT_0_DYNADDR_PARITY);
 	dat_w0_write(dat_idx, dat_w0);
 }
 
-- 
2.45.2


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