[PATCH net-next 6/8] net: stmmac: introduce setter/getter for timestamp configuration

[alexis.lothore@bootlin.com]

From: Alexis Lothoré <alexis.lothore@bootlin.com>

stmmac_hwtstamp_set currently writes the whole Timestamp Control register
when configuring hardware timestamping. It is done for all GMAC variants,
and leads to issues with DWMAC1000: this version also bears the Auxiliary
Snapshot Trigger bit in the same register. This field, which is set
independently with during PTP_CLK_REQ_EXTTS ioctl, is then overwritten when
stmmac_hwtstamp_set is called.
Introduce setter and getter to allow modifying only relevant parts of the
timestamp control register instead of overwriting it all.

Signed-off-by: Alexis Lothoré <alexis.lothore@bootlin.com>
---
 drivers/net/ethernet/stmicro/stmmac/hwif.h            |  9 ++++++---
 drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c | 10 ++++++++--
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c     |  4 ++--
 3 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/hwif.h b/drivers/net/ethernet/stmicro/stmmac/hwif.h
index d0b2f13510aa..927324e3d748 100644
--- a/drivers/net/ethernet/stmicro/stmmac/hwif.h
+++ b/drivers/net/ethernet/stmicro/stmmac/hwif.h
@@ -534,7 +534,8 @@ struct stmmac_ops {
 
 /* PTP and HW Timer helpers */
 struct stmmac_hwtimestamp {
-	void (*config_hw_tstamping) (void __iomem *ioaddr, u32 data);
+	void (*config_hw_tstamping_set)(void __iomem *ioaddr, u32 data);
+	u32 (*config_hw_tstamping_get)(void __iomem *ioaddr);
 	void (*config_sub_second_increment)(void __iomem *ioaddr, u32 ptp_clock,
 					   int gmac4, u32 *ssinc);
 	int (*init_systime) (void __iomem *ioaddr, u32 sec, u32 nsec);
@@ -546,8 +547,10 @@ struct stmmac_hwtimestamp {
 	void (*timestamp_interrupt)(struct stmmac_priv *priv);
 };
 
-#define stmmac_config_hw_tstamping(__priv, __args...) \
-	stmmac_do_void_callback(__priv, ptp, config_hw_tstamping, __args)
+#define stmmac_config_hw_tstamping_set(__priv, __args...) \
+	stmmac_do_void_callback(__priv, ptp, config_hw_tstamping_set, __args)
+#define stmmac_config_hw_tstamping_get(__priv, __args...) \
+	stmmac_do_callback(__priv, ptp, config_hw_tstamping_get, __args)
 #define stmmac_config_sub_second_increment(__priv, __args...) \
 	stmmac_do_void_callback(__priv, ptp, config_sub_second_increment, __args)
 #define stmmac_init_systime(__priv, __args...) \
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c
index 2cd0ec17f4c6..cbb94d3e0fa1 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c
@@ -18,11 +18,16 @@
 #include "dwmac4.h"
 #include "stmmac.h"
 
-static void config_hw_tstamping(void __iomem *ioaddr, u32 data)
+static void config_hw_tstamping_set(void __iomem *ioaddr, u32 data)
 {
 	writel(data, ioaddr + PTP_TCR);
 }
 
+static u32 config_hw_tstamping_get(void __iomem *ioaddr)
+{
+	return readl(ioaddr + PTP_TCR);
+}
+
 static void config_sub_second_increment(void __iomem *ioaddr,
 		u32 ptp_clock, int gmac4, u32 *ssinc)
 {
@@ -163,7 +168,8 @@ static void get_systime(void __iomem *ioaddr, u64 *systime)
 }
 
 const struct stmmac_hwtimestamp stmmac_ptp = {
-	.config_hw_tstamping = config_hw_tstamping,
+	.config_hw_tstamping_set = config_hw_tstamping_set,
+	.config_hw_tstamping_get = config_hw_tstamping_get,
 	.init_systime = init_systime,
 	.config_sub_second_increment = config_sub_second_increment,
 	.config_addend = config_addend,
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 4f0ef73d5121..528d2e010926 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -792,7 +792,7 @@ static int stmmac_hwtstamp_set(struct net_device *dev, struct ifreq *ifr)
 				       ts_master_en | snap_type_sel;
 	}
 
-	stmmac_config_hw_tstamping(priv, priv->ptpaddr, priv->systime_flags);
+	stmmac_config_hw_tstamping_set(priv, priv->ptpaddr, priv->systime_flags);
 
 	memcpy(&priv->tstamp_config, &config, sizeof(config));
 
@@ -841,7 +841,7 @@ int stmmac_init_tstamp_counter(struct stmmac_priv *priv, u32 systime_flags)
 	if (!(priv->dma_cap.time_stamp || priv->dma_cap.atime_stamp))
 		return -EOPNOTSUPP;
 
-	stmmac_config_hw_tstamping(priv, priv->ptpaddr, systime_flags);
+	stmmac_config_hw_tstamping_set(priv, priv->ptpaddr, systime_flags);
 	priv->systime_flags = systime_flags;
 
 	/* program Sub Second Increment reg */
-- 
2.41.0