[PATCH net-next 1/5] net: ethernet: oa_tc6: Allow custom reset settle time values

[Iustin Stolniceanu <iustin.stolniceanu@analog.com>]

From: Ciprian Regus <ciprian.regus@analog.com>

oa_tc6_init() waits a fixed 1 ms after deasserting the reset GPIO
before accessing the MAC-PHY. The reset timing parameters of a MAC-PHY
device are outside of the OA TC6 scope. For example, the ADIN1110 needs
up to 50 ms after RESET is deasserted before its registers can be
accessed.

Add a reset_settle_us field to struct oa_tc6_quirks so drivers can
set this time. If it is not set, the GPIO reset keeps the existing
1 ms wait.

When set, also apply the wait after the software reset, before polling
STATUS0 for RESETC. This is needed for devices that tristate their SDO
pin during a reset. Drivers that don't set reset_settle_us keep the
current behaviour.

Signed-off-by: Ciprian Regus <ciprian.regus@analog.com>
Co-developed-by: Iustin Stolniceanu <iustin.stolniceanu@analog.com>
Signed-off-by: Iustin Stolniceanu <iustin.stolniceanu@analog.com>
---
 drivers/net/ethernet/oa_tc6.c | 18 ++++++++++++++----
 include/linux/oa_tc6.h        |  2 ++
 2 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/oa_tc6.c b/drivers/net/ethernet/oa_tc6.c
index 364027c39fa4..68437b226528 100644
--- a/drivers/net/ethernet/oa_tc6.c
+++ b/drivers/net/ethernet/oa_tc6.c
@@ -89,6 +89,7 @@ struct oa_tc6 {
 	bool int_flag;
 	bool disable_traffic;
 	bool prot_ctrl;
+	u32 reset_settle_us;
 	enum oa_tc6_quirk_flag quirk_flags;
 	struct gpio_desc *reset_gpio;
 };
@@ -652,6 +653,9 @@ static int oa_tc6_sw_reset_macphy(struct oa_tc6 *tc6)
 	if (ret)
 		return ret;
 
+	if (tc6->reset_settle_us)
+		fsleep(tc6->reset_settle_us);
+
 	/* Poll for soft reset complete for every 1ms until 1s timeout */
 	ret = readx_poll_timeout(oa_tc6_read_status0, tc6, regval,
 				 regval & OA_TC6_STATUS0_RESETC,
@@ -1474,8 +1478,10 @@ struct oa_tc6 *oa_tc6_init(struct spi_device *spi, struct net_device *netdev,
 	mutex_init(&tc6->spi_ctrl_lock);
 	spin_lock_init(&tc6->tx_skb_lock);
 
-	if (quirks)
+	if (quirks) {
 		tc6->quirk_flags = quirks->quirk_flags;
+		tc6->reset_settle_us = quirks->reset_settle_us;
+	}
 
 	/* Set the SPI controller to pump at realtime priority */
 	tc6->spi->rt = true;
@@ -1515,12 +1521,16 @@ struct oa_tc6 *oa_tc6_init(struct spi_device *spi, struct net_device *netdev,
 					     "failed to get reset gpio\n"));
 
 	if (tc6->reset_gpio) {
-		/* Keep the reset asserted for 10 us and then allow 1 ms of
-		 * settle time for the crystal oscillator startup.
+		/* Keep the reset asserted for 10 us and then allow the reset
+		 * settle time (1 ms by default) for the crystal oscillator
+		 * startup.
 		 */
 		fsleep(10);
 		gpiod_set_value_cansleep(tc6->reset_gpio, 0);
-		fsleep(1000);
+		if (tc6->reset_settle_us)
+			fsleep(tc6->reset_settle_us);
+		else
+			fsleep(1000);
 	}
 
 	/* Check the PROTE bit status so that we can reset the device */
diff --git a/include/linux/oa_tc6.h b/include/linux/oa_tc6.h
index 27f652d4920b..139dd4c33950 100644
--- a/include/linux/oa_tc6.h
+++ b/include/linux/oa_tc6.h
@@ -72,6 +72,8 @@ enum oa_tc6_quirk_flag {
 
 struct oa_tc6_quirks {
 	enum oa_tc6_quirk_flag quirk_flags;
+	/* Wait after the GPIO reset (default 1 ms) and the software reset */
+	u32 reset_settle_us;
 };
 
 struct oa_tc6 *oa_tc6_init(struct spi_device *spi, struct net_device *netdev,
-- 
2.43.0