diff mbox series

[net-next,12/14] ptp: stmac: convert to .adjfine and adjust_by_scaled_ppm

Message ID 20220818222742.1070935-13-jacob.e.keller@intel.com (mailing list archive)
State Changes Requested
Delegated to: Netdev Maintainers
Headers show
Series ptp: convert drivers to .adjfine | expand

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netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit fail Errors and warnings before: 95 this patch: 95
netdev/cc_maintainers warning 2 maintainers not CCed: linux-stm32@st-md-mailman.stormreply.com linux-arm-kernel@lists.infradead.org
netdev/build_clang fail Errors and warnings before: 10 this patch: 10
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn fail Errors and warnings before: 95 this patch: 95
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 43 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Jacob Keller Aug. 18, 2022, 10:27 p.m. UTC
The stmac implementation of .adjfreq is implemented in terms of a
straight forward "base * ppb / 1 billion" calculation.

Convert this driver to .adjfine and use the adjust_by_scaled_ppm helper
function to perform the calculation of the new addend.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Cc: Alexandre Torgue <alexandre.torgue@foss.st.com>
Cc: Jose Abreu <joabreu@synopsys.com>
---

I do not have this hardware, and have only compile tested the change.

 .../net/ethernet/stmicro/stmmac/stmmac_ptp.c  | 23 ++++++-------------
 1 file changed, 7 insertions(+), 16 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c
index 4d11980dcd64..0d5e6819ee5d 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c
@@ -15,29 +15,20 @@ 
  * stmmac_adjust_freq
  *
  * @ptp: pointer to ptp_clock_info structure
- * @ppb: desired period change in parts ber billion
+ * @scaled_ppm: desired period change in scaled parts per million
  *
  * Description: this function will adjust the frequency of hardware clock.
+ *
+ * Scaled parts per million is ppm with a 16-bit binary fractional field.
  */
-static int stmmac_adjust_freq(struct ptp_clock_info *ptp, s32 ppb)
+static int stmmac_adjust_freq(struct ptp_clock_info *ptp, long scaled_ppm)
 {
 	struct stmmac_priv *priv =
 	    container_of(ptp, struct stmmac_priv, ptp_clock_ops);
 	unsigned long flags;
-	u32 diff, addend;
-	int neg_adj = 0;
-	u64 adj;
+	u32 addend;
 
-	if (ppb < 0) {
-		neg_adj = 1;
-		ppb = -ppb;
-	}
-
-	addend = priv->default_addend;
-	adj = addend;
-	adj *= ppb;
-	diff = div_u64(adj, 1000000000ULL);
-	addend = neg_adj ? (addend - diff) : (addend + diff);
+	addend = (u32)adjust_by_scaled_ppm(priv->default_addend, scaled_ppm);
 
 	write_lock_irqsave(&priv->ptp_lock, flags);
 	stmmac_config_addend(priv, priv->ptpaddr, addend);
@@ -269,7 +260,7 @@  static struct ptp_clock_info stmmac_ptp_clock_ops = {
 	.n_per_out = 0, /* will be overwritten in stmmac_ptp_register */
 	.n_pins = 0,
 	.pps = 0,
-	.adjfreq = stmmac_adjust_freq,
+	.adjfine = stmmac_adjust_freq,
 	.adjtime = stmmac_adjust_time,
 	.gettime64 = stmmac_get_time,
 	.settime64 = stmmac_set_time,