From 9a236b543f6b1e85bb18b00ce5c92bfff84a47ab Mon Sep 17 00:00:00 2001 From: Luiz Angelo Daros de Luca Date: Sun, 13 Feb 2022 23:20:11 -0300 Subject: [PATCH 1/2] net: dsa: realtek: realtek-smi: clean-up reset MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When reset GPIO was missing, the driver was still printing an info message and still trying to assert the reset. Although gpiod_set_value() will silently ignore calls with NULL gpio_desc, it is better to make it clear the driver might allow gpio_desc to be NULL. The initial value for the reset pin was changed to GPIOD_OUT_LOW, followed by a gpiod_set_value() asserting the reset. This way, it will be easier to spot if and where the reset really happens. A new "asserted RESET" message was added just after the reset is asserted, similar to the existing "deasserted RESET" message. Both messages were demoted to dbg. The code comment is not needed anymore. Signed-off-by: Luiz Angelo Daros de Luca Acked-by: Arınç ÜNAL Signed-off-by: David S. Miller --- drivers/net/dsa/realtek/realtek-smi.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-) diff --git a/drivers/net/dsa/realtek/realtek-smi.c b/drivers/net/dsa/realtek/realtek-smi.c index 946fbbd70153..33cf5a0692de 100644 --- a/drivers/net/dsa/realtek/realtek-smi.c +++ b/drivers/net/dsa/realtek/realtek-smi.c @@ -420,16 +420,19 @@ static int realtek_smi_probe(struct platform_device *pdev) /* TODO: if power is software controlled, set up any regulators here */ - /* Assert then deassert RESET */ - priv->reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH); + priv->reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW); if (IS_ERR(priv->reset)) { dev_err(dev, "failed to get RESET GPIO\n"); return PTR_ERR(priv->reset); } - msleep(REALTEK_SMI_HW_STOP_DELAY); - gpiod_set_value(priv->reset, 0); - msleep(REALTEK_SMI_HW_START_DELAY); - dev_info(dev, "deasserted RESET\n"); + if (priv->reset) { + gpiod_set_value(priv->reset, 1); + dev_dbg(dev, "asserted RESET\n"); + msleep(REALTEK_SMI_HW_STOP_DELAY); + gpiod_set_value(priv->reset, 0); + msleep(REALTEK_SMI_HW_START_DELAY); + dev_dbg(dev, "deasserted RESET\n"); + } /* Fetch MDIO pins */ priv->mdc = devm_gpiod_get_optional(dev, "mdc", GPIOD_OUT_LOW); @@ -474,7 +477,10 @@ static int realtek_smi_remove(struct platform_device *pdev) dsa_unregister_switch(priv->ds); if (priv->slave_mii_bus) of_node_put(priv->slave_mii_bus->dev.of_node); - gpiod_set_value(priv->reset, 1); + + /* leave the device reset asserted */ + if (priv->reset) + gpiod_set_value(priv->reset, 1); platform_set_drvdata(pdev, NULL); From 05f7b042c5a6d37f67e328388f31018e48711194 Mon Sep 17 00:00:00 2001 From: Luiz Angelo Daros de Luca Date: Sun, 13 Feb 2022 23:20:12 -0300 Subject: [PATCH 2/2] net: dsa: realtek: realtek-mdio: reset before setup MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Some devices, like the switch in Banana Pi BPI R64 only starts to answer after a HW reset. It is the same reset code from realtek-smi. Reported-by: Frank Wunderlich Signed-off-by: Luiz Angelo Daros de Luca Tested-by: Frank Wunderlich Reviewed-by: Linus Walleij Reviewed-by: Alvin Šipraga Acked-by: Arınç ÜNAL Signed-off-by: David S. Miller --- drivers/net/dsa/realtek/realtek-mdio.c | 19 +++++++++++++++++++ drivers/net/dsa/realtek/realtek-smi.c | 6 ++---- drivers/net/dsa/realtek/realtek.h | 3 +++ 3 files changed, 24 insertions(+), 4 deletions(-) diff --git a/drivers/net/dsa/realtek/realtek-mdio.c b/drivers/net/dsa/realtek/realtek-mdio.c index 0c5f2bdced9d..0308be95d00a 100644 --- a/drivers/net/dsa/realtek/realtek-mdio.c +++ b/drivers/net/dsa/realtek/realtek-mdio.c @@ -152,6 +152,21 @@ static int realtek_mdio_probe(struct mdio_device *mdiodev) /* TODO: if power is software controlled, set up any regulators here */ priv->leds_disabled = of_property_read_bool(np, "realtek,disable-leds"); + priv->reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW); + if (IS_ERR(priv->reset)) { + dev_err(dev, "failed to get RESET GPIO\n"); + return PTR_ERR(priv->reset); + } + + if (priv->reset) { + gpiod_set_value(priv->reset, 1); + dev_dbg(dev, "asserted RESET\n"); + msleep(REALTEK_HW_STOP_DELAY); + gpiod_set_value(priv->reset, 0); + msleep(REALTEK_HW_START_DELAY); + dev_dbg(dev, "deasserted RESET\n"); + } + ret = priv->ops->detect(priv); if (ret) { dev_err(dev, "unable to detect switch\n"); @@ -185,6 +200,10 @@ static void realtek_mdio_remove(struct mdio_device *mdiodev) dsa_unregister_switch(priv->ds); + /* leave the device reset asserted */ + if (priv->reset) + gpiod_set_value(priv->reset, 1); + dev_set_drvdata(&mdiodev->dev, NULL); } diff --git a/drivers/net/dsa/realtek/realtek-smi.c b/drivers/net/dsa/realtek/realtek-smi.c index 33cf5a0692de..8806b74bd7a8 100644 --- a/drivers/net/dsa/realtek/realtek-smi.c +++ b/drivers/net/dsa/realtek/realtek-smi.c @@ -43,8 +43,6 @@ #include "realtek.h" #define REALTEK_SMI_ACK_RETRY_COUNT 5 -#define REALTEK_SMI_HW_STOP_DELAY 25 /* msecs */ -#define REALTEK_SMI_HW_START_DELAY 100 /* msecs */ static inline void realtek_smi_clk_delay(struct realtek_priv *priv) { @@ -428,9 +426,9 @@ static int realtek_smi_probe(struct platform_device *pdev) if (priv->reset) { gpiod_set_value(priv->reset, 1); dev_dbg(dev, "asserted RESET\n"); - msleep(REALTEK_SMI_HW_STOP_DELAY); + msleep(REALTEK_HW_STOP_DELAY); gpiod_set_value(priv->reset, 0); - msleep(REALTEK_SMI_HW_START_DELAY); + msleep(REALTEK_HW_START_DELAY); dev_dbg(dev, "deasserted RESET\n"); } diff --git a/drivers/net/dsa/realtek/realtek.h b/drivers/net/dsa/realtek/realtek.h index 3512b832b148..e7d3e1bcf8b8 100644 --- a/drivers/net/dsa/realtek/realtek.h +++ b/drivers/net/dsa/realtek/realtek.h @@ -13,6 +13,9 @@ #include #include +#define REALTEK_HW_STOP_DELAY 25 /* msecs */ +#define REALTEK_HW_START_DELAY 100 /* msecs */ + struct realtek_ops; struct dentry; struct inode;