netdev - [net-next 04/14] ptp_phc: convert to .adjfine and ptp_adj_scaled

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Date:   Thu, 18 Aug 2022 15:27:32 -0700
From:   Jacob Keller <jacob.e.keller@...el.com>
To:     netdev@...r.kernel.org
Cc:     Jacob Keller <jacob.e.keller@...el.com>,
        "K. Y. Srinivasan" <kys@...rosoft.com>,
        Haiyang Zhang <haiyangz@...rosoft.com>,
        Stephen Hemminger <sthemmin@...rosoft.com>,
        Wei Liu <wei.liu@...nel.org>, Dexuan Cui <decui@...rosoft.com>,
        Tom Lendacky <thomas.lendacky@....com>,
        Shyam Sundar S K <Shyam-sundar.S-k@....com>,
        "David S. Miller" <davem@...emloft.net>,
        Eric Dumazet <edumazet@...gle.com>,
        Jakub Kicinski <kuba@...nel.org>,
        Paolo Abeni <pabeni@...hat.com>,
        Siva Reddy Kallam <siva.kallam@...adcom.com>,
        Prashant Sreedharan <prashant@...adcom.com>,
        Michael Chan <mchan@...adcom.com>,
        Yisen Zhuang <yisen.zhuang@...wei.com>,
        Salil Mehta <salil.mehta@...wei.com>,
        Jesse Brandeburg <jesse.brandeburg@...el.com>,
        Tony Nguyen <anthony.l.nguyen@...el.com>,
        Tariq Toukan <tariqt@...dia.com>,
        Saeed Mahameed <saeedm@...dia.com>,
        Leon Romanovsky <leon@...nel.org>,
        Bryan Whitehead <bryan.whitehead@...rochip.com>,
        Sergey Shtylyov <s.shtylyov@....ru>,
        Giuseppe Cavallaro <peppe.cavallaro@...com>,
        Alexandre Torgue <alexandre.torgue@...s.st.com>,
        Jose Abreu <joabreu@...opsys.com>,
        Maxime Coquelin <mcoquelin.stm32@...il.com>,
        Richard Cochran <richardcochran@...il.com>,
        Vivek Thampi <vithampi@...are.com>,
        VMware PV-Drivers Reviewers <pv-drivers@...are.com>,
        Jie Wang <wangjie125@...wei.com>,
        Guangbin Huang <huangguangbin2@...wei.com>,
        Eran Ben Elisha <eranbe@...dia.com>,
        Aya Levin <ayal@...dia.com>,
        Cai Huoqing <cai.huoqing@...ux.dev>,
        Biju Das <biju.das.jz@...renesas.com>,
        Lad Prabhakar <prabhakar.mahadev-lad.rj@...renesas.com>,
        Phil Edworthy <phil.edworthy@...esas.com>,
        Jiasheng Jiang <jiasheng@...as.ac.cn>,
        "Gustavo A. R. Silva" <gustavoars@...nel.org>,
        Linus Walleij <linus.walleij@...aro.org>,
        Wan Jiabing <wanjiabing@...o.com>,
        Lv Ruyi <lv.ruyi@....com.cn>, Arnd Bergmann <arnd@...db.de>,
        Takahiro Shimizu <tshimizu818@...il.com>
Subject: [net-next 04/14] ptp_phc: convert to .adjfine and ptp_adj_scaled_ppm

The ptp_phc implementation of .adjfreq is implemented in terms of a
straight forward "base * ppb / 1 billion" calculation.

Convert this driver to .adjfine and use the new ptp_adj_scaled_ppm function
to calculate the adjustment.

Signed-off-by: Jacob Keller <jacob.e.keller@...el.com>
Cc: Takahiro Shimizu <tshimizu818@...il.com>
Cc: Richard Cochran <richardcochran@...il.com>
---

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

 drivers/ptp/ptp_pch.c | 19 ++++---------------
 1 file changed, 4 insertions(+), 15 deletions(-)

diff --git a/drivers/ptp/ptp_pch.c b/drivers/ptp/ptp_pch.c
index 7d4da9e605ef..6bfe5c8eb61e 100644
--- a/drivers/ptp/ptp_pch.c
+++ b/drivers/ptp/ptp_pch.c
@@ -336,24 +336,13 @@ static irqreturn_t isr(int irq, void *priv)
  * PTP clock operations
  */
 
-static int ptp_pch_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
+static int ptp_pch_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
 {
-	u64 adj;
-	u32 diff, addend;
-	int neg_adj = 0;
+	u32 addend;
 	struct pch_dev *pch_dev = container_of(ptp, struct pch_dev, caps);
 	struct pch_ts_regs __iomem *regs = pch_dev->regs;
 
-	if (ppb < 0) {
-		neg_adj = 1;
-		ppb = -ppb;
-	}
-	addend = DEFAULT_ADDEND;
-	adj = addend;
-	adj *= ppb;
-	diff = div_u64(adj, 1000000000ULL);
-
-	addend = neg_adj ? addend - diff : addend + diff;
+	addend = (u32)adjust_by_scaled_ppm(DEFAULT_ADDEND, scaled_ppm);
 
 	iowrite32(addend, &regs->addend);
 
@@ -440,7 +429,7 @@ static const struct ptp_clock_info ptp_pch_caps = {
 	.n_ext_ts	= N_EXT_TS,
 	.n_pins		= 0,
 	.pps		= 0,
-	.adjfreq	= ptp_pch_adjfreq,
+	.adjfine	= ptp_pch_adjfine,
 	.adjtime	= ptp_pch_adjtime,
 	.gettime64	= ptp_pch_gettime,
 	.settime64	= ptp_pch_settime,
-- 
2.37.1.208.ge72d93e88cb2