[PATCH net-next v2 2/7] 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, and polls STATUS0 for RESETC right after
the software reset. 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 and up to 10 ms after a software reset before
its registers can be accessed, and it tristates its SDO pin during the
reset.

Add hwreset_settle_us and softreset_settle_us fields to struct
oa_tc6_quirks so drivers can set these times. If hwreset_settle_us is
not set, the GPIO reset keeps the existing 1 ms wait. If
softreset_settle_us is not set, there is no wait after the software
reset, as before.

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>
Reviewed-by: Alvin Šipraga <alvin.sipraga@analog.com>
---
 drivers/net/ethernet/oa_tc6.c | 17 +++++++++++++----
 include/linux/oa_tc6.h        |  4 ++++
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/oa_tc6.c b/drivers/net/ethernet/oa_tc6.c
index 364027c39fa4..549997ba363a 100644
--- a/drivers/net/ethernet/oa_tc6.c
+++ b/drivers/net/ethernet/oa_tc6.c
@@ -89,6 +89,8 @@ struct oa_tc6 {
 	bool int_flag;
 	bool disable_traffic;
 	bool prot_ctrl;
+	u32 hwreset_settle_us;
+	u32 softreset_settle_us;
 	enum oa_tc6_quirk_flag quirk_flags;
 	struct gpio_desc *reset_gpio;
 };
@@ -652,6 +654,8 @@ static int oa_tc6_sw_reset_macphy(struct oa_tc6 *tc6)
 	if (ret)
 		return ret;
 
+	fsleep(tc6->softreset_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 +1478,13 @@ 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)
+	tc6->hwreset_settle_us = 1000;
+	if (quirks) {
 		tc6->quirk_flags = quirks->quirk_flags;
+		if (quirks->hwreset_settle_us)
+			tc6->hwreset_settle_us = quirks->hwreset_settle_us;
+		tc6->softreset_settle_us = quirks->softreset_settle_us;
+	}
 
 	/* Set the SPI controller to pump at realtime priority */
 	tc6->spi->rt = true;
@@ -1515,12 +1524,12 @@ 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).
 		 */
 		fsleep(10);
 		gpiod_set_value_cansleep(tc6->reset_gpio, 0);
-		fsleep(1000);
+		fsleep(tc6->hwreset_settle_us);
 	}
 
 	/* 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 6eac6b842156..f676e712e75d 100644
--- a/include/linux/oa_tc6.h
+++ b/include/linux/oa_tc6.h
@@ -73,6 +73,10 @@ enum oa_tc6_quirk_flag {
 
 struct oa_tc6_quirks {
 	enum oa_tc6_quirk_flag quirk_flags;
+	/* Wait after deasserting the reset GPIO, 1 ms if not set */
+	u32 hwreset_settle_us;
+	/* Wait after the software reset, before polling for RESETC */
+	u32 softreset_settle_us;
 };
 
 struct oa_tc6 *oa_tc6_init(struct spi_device *spi, struct net_device *netdev,
-- 
2.43.0