diff mbox series

[net-next,v9,5/6] net: tn40xx: add mdio bus support

Message ID 20240605232608.65471-6-fujita.tomonori@gmail.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series add ethernet driver for Tehuti Networks TN40xx chips | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next, async
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 907 this patch: 907
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers warning 1 maintainers not CCed: edumazet@google.com
netdev/build_clang success Errors and warnings before: 905 this patch: 905
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 912 this patch: 912
netdev/checkpatch warning WARNING: added, moved or deleted file(s), does MAINTAINERS need updating?
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-06-07--09-00 (tests: 1041)

Commit Message

FUJITA Tomonori June 5, 2024, 11:26 p.m. UTC
This patch adds supports for mdio bus. A later path adds PHYLIB
support on the top of this.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
---
 drivers/net/ethernet/tehuti/Makefile    |   2 +-
 drivers/net/ethernet/tehuti/tn40.h      |   4 +
 drivers/net/ethernet/tehuti/tn40_mdio.c | 143 ++++++++++++++++++++++++
 3 files changed, 148 insertions(+), 1 deletion(-)
 create mode 100644 drivers/net/ethernet/tehuti/tn40_mdio.c

Comments

Hans-Frieder Vogt June 9, 2024, 11:22 a.m. UTC | #1
On 06.06.2024 01.26, FUJITA Tomonori wrote:
> +
> +static void tn40_mdio_set_speed(struct tn40_priv *priv, u32 speed)
> +{
> +	void __iomem *regs = priv->regs;
> +	int mdio_cfg;
> +
> +	mdio_cfg = readl(regs + TN40_REG_MDIO_CMD_STAT);
the result of the readl is nowhere used. And as far as I have seen it is
not needed to trigger anything. Therefore I suggest you delete this read
operation.
> +	if (speed == 1)
why not use the defined value TN40_MDIO_SPEED_1MHZ here? It would make
the logic of the function even clearer.
> +		mdio_cfg = (0x7d << 7) | 0x08;	/* 1MHz */
> +	else
> +		mdio_cfg = 0xA08;	/* 6MHz */
> +	mdio_cfg |= (1 << 6);
> +	writel(mdio_cfg, regs + TN40_REG_MDIO_CMD_STAT);
> +	msleep(100);
> +}
> +
FUJITA Tomonori June 10, 2024, 7:35 a.m. UTC | #2
On Sun, 9 Jun 2024 13:22:56 +0200
Hans-Frieder Vogt <hfdevel@gmx.net> wrote:

> On 06.06.2024 01.26, FUJITA Tomonori wrote:
>> +
>> +static void tn40_mdio_set_speed(struct tn40_priv *priv, u32 speed)
>> +{
>> +	void __iomem *regs = priv->regs;
>> +	int mdio_cfg;
>> +
>> +	mdio_cfg = readl(regs + TN40_REG_MDIO_CMD_STAT);
> the result of the readl is nowhere used. And as far as I have seen it
> is
> not needed to trigger anything. Therefore I suggest you delete this
> read
> operation.

I thought that reading the register has some effect but seems the
hardware works without the above line. I'll drop it in v10.


>> +	if (speed == 1)
> why not use the defined value TN40_MDIO_SPEED_1MHZ here? It would make
> the logic of the function even clearer.

Yeah. I left the original code alone. I'll fix in v10.

Thanks!
Russell King (Oracle) June 10, 2024, 10:04 a.m. UTC | #3
On Thu, Jun 06, 2024 at 08:26:07AM +0900, FUJITA Tomonori wrote:
> +static int tn40_mdio_get(struct tn40_priv *priv, u32 *val)

I think this would be better named "tn40_mdio_wait_nonbusy()" because
that seems to be this function's primary purpose.

> +static int tn40_mdio_read_cb(struct mii_bus *mii_bus, int addr, int devnum,
> +			     int regnum)
> +static int tn40_mdio_write_cb(struct mii_bus *mii_bus, int addr, int devnum,
> +			      int regnum, u16 val)

I think it would be better to name these both with a _c45 suffix (which
tells us that they're clause 45 accessors) rather than using _cb
(presumably for callback which tells us nothing!)

Thanks!
FUJITA Tomonori June 10, 2024, 12:05 p.m. UTC | #4
On Mon, 10 Jun 2024 11:04:54 +0100
"Russell King (Oracle)" <linux@armlinux.org.uk> wrote:

> On Thu, Jun 06, 2024 at 08:26:07AM +0900, FUJITA Tomonori wrote:
>> +static int tn40_mdio_get(struct tn40_priv *priv, u32 *val)
> 
> I think this would be better named "tn40_mdio_wait_nonbusy()" because
> that seems to be this function's primary purpose.

Surely, sounds much better. I'll rename.

>> +static int tn40_mdio_read_cb(struct mii_bus *mii_bus, int addr, int devnum,
>> +			     int regnum)
>> +static int tn40_mdio_write_cb(struct mii_bus *mii_bus, int addr, int devnum,
>> +			      int regnum, u16 val)
> 
> I think it would be better to name these both with a _c45 suffix (which
> tells us that they're clause 45 accessors) rather than using _cb
> (presumably for callback which tells us nothing!)

Indeed. I'll use tn40_mdio_read_c45/tn40_mdio_write_c45 names in
v10. I felt that _cb was meaningless but I couldn't come up with good
names.

Thanks!
diff mbox series

Patch

diff --git a/drivers/net/ethernet/tehuti/Makefile b/drivers/net/ethernet/tehuti/Makefile
index 1c468d99e476..7a0fe586a243 100644
--- a/drivers/net/ethernet/tehuti/Makefile
+++ b/drivers/net/ethernet/tehuti/Makefile
@@ -5,5 +5,5 @@ 
 
 obj-$(CONFIG_TEHUTI) += tehuti.o
 
-tn40xx-y := tn40.o
+tn40xx-y := tn40.o tn40_mdio.o
 obj-$(CONFIG_TEHUTI_TN40) += tn40xx.o
diff --git a/drivers/net/ethernet/tehuti/tn40.h b/drivers/net/ethernet/tehuti/tn40.h
index afe85ce44d41..05a9adf9fe5a 100644
--- a/drivers/net/ethernet/tehuti/tn40.h
+++ b/drivers/net/ethernet/tehuti/tn40.h
@@ -141,6 +141,8 @@  struct tn40_priv {
 	u32 b0_len;
 	dma_addr_t b0_dma; /* Physical address of buffer */
 	char *b0_va; /* Virtual address of buffer */
+
+	struct mii_bus *mdio;
 };
 
 /* RX FREE descriptor - 64bit */
@@ -218,4 +220,6 @@  static inline void tn40_write_reg(struct tn40_priv *priv, u32 reg, u32 val)
 	writel(val, priv->regs + reg);
 }
 
+int tn40_mdiobus_init(struct tn40_priv *priv);
+
 #endif /* _TN40XX_H */
diff --git a/drivers/net/ethernet/tehuti/tn40_mdio.c b/drivers/net/ethernet/tehuti/tn40_mdio.c
new file mode 100644
index 000000000000..8a1f0c9f51b2
--- /dev/null
+++ b/drivers/net/ethernet/tehuti/tn40_mdio.c
@@ -0,0 +1,143 @@ 
+// SPDX-License-Identifier: GPL-2.0+
+/* Copyright (c) Tehuti Networks Ltd. */
+
+#include <linux/netdevice.h>
+#include <linux/pci.h>
+#include <linux/phylink.h>
+
+#include "tn40.h"
+
+#define TN40_MDIO_DEVAD_MASK GENMASK(4, 0)
+#define TN40_MDIO_PRTAD_MASK GENMASK(9, 5)
+#define TN40_MDIO_CMD_VAL(device, port)			\
+	(FIELD_PREP(TN40_MDIO_DEVAD_MASK, (device)) |	\
+	 (FIELD_PREP(TN40_MDIO_PRTAD_MASK, (port))))
+#define TN40_MDIO_CMD_READ BIT(15)
+
+static void tn40_mdio_set_speed(struct tn40_priv *priv, u32 speed)
+{
+	void __iomem *regs = priv->regs;
+	int mdio_cfg;
+
+	mdio_cfg = readl(regs + TN40_REG_MDIO_CMD_STAT);
+	if (speed == 1)
+		mdio_cfg = (0x7d << 7) | 0x08;	/* 1MHz */
+	else
+		mdio_cfg = 0xA08;	/* 6MHz */
+	mdio_cfg |= (1 << 6);
+	writel(mdio_cfg, regs + TN40_REG_MDIO_CMD_STAT);
+	msleep(100);
+}
+
+static u32 tn40_mdio_stat(struct tn40_priv *priv)
+{
+	void __iomem *regs = priv->regs;
+
+	return readl(regs + TN40_REG_MDIO_CMD_STAT);
+}
+
+static int tn40_mdio_get(struct tn40_priv *priv, u32 *val)
+{
+	u32 stat;
+	int ret;
+
+	ret = readx_poll_timeout_atomic(tn40_mdio_stat, priv, stat,
+					TN40_GET_MDIO_BUSY(stat) == 0, 10,
+					10000);
+	if (val)
+		*val = stat;
+	return ret;
+}
+
+static int tn40_mdio_read(struct tn40_priv *priv, int port, int device,
+			  u16 regnum)
+{
+	void __iomem *regs = priv->regs;
+	u32 i;
+
+	/* wait until MDIO is not busy */
+	if (tn40_mdio_get(priv, NULL))
+		return -EIO;
+
+	i = TN40_MDIO_CMD_VAL(device, port);
+	writel(i, regs + TN40_REG_MDIO_CMD);
+	writel((u32)regnum, regs + TN40_REG_MDIO_ADDR);
+	if (tn40_mdio_get(priv, NULL))
+		return -EIO;
+
+	writel(TN40_MDIO_CMD_READ | i, regs + TN40_REG_MDIO_CMD);
+	/* read CMD_STAT until not busy */
+	if (tn40_mdio_get(priv, NULL))
+		return -EIO;
+
+	return lower_16_bits(readl(regs + TN40_REG_MDIO_DATA));
+}
+
+static int tn40_mdio_write(struct tn40_priv *priv, int port, int device,
+			   u16 regnum, u16 data)
+{
+	void __iomem *regs = priv->regs;
+	u32 tmp_reg = 0;
+	int ret;
+
+	/* wait until MDIO is not busy */
+	if (tn40_mdio_get(priv, NULL))
+		return -EIO;
+	writel(TN40_MDIO_CMD_VAL(device, port), regs + TN40_REG_MDIO_CMD);
+	writel((u32)regnum, regs + TN40_REG_MDIO_ADDR);
+	if (tn40_mdio_get(priv, NULL))
+		return -EIO;
+	writel((u32)data, regs + TN40_REG_MDIO_DATA);
+	/* read CMD_STAT until not busy */
+	ret = tn40_mdio_get(priv, &tmp_reg);
+	if (ret)
+		return -EIO;
+
+	if (TN40_GET_MDIO_RD_ERR(tmp_reg)) {
+		dev_err(&priv->pdev->dev, "MDIO error after write command\n");
+		return -EIO;
+	}
+	return 0;
+}
+
+static int tn40_mdio_read_cb(struct mii_bus *mii_bus, int addr, int devnum,
+			     int regnum)
+{
+	return tn40_mdio_read(mii_bus->priv, addr, devnum, regnum);
+}
+
+static int tn40_mdio_write_cb(struct mii_bus *mii_bus, int addr, int devnum,
+			      int regnum, u16 val)
+{
+	return  tn40_mdio_write(mii_bus->priv, addr, devnum, regnum, val);
+}
+
+int tn40_mdiobus_init(struct tn40_priv *priv)
+{
+	struct pci_dev *pdev = priv->pdev;
+	struct mii_bus *bus;
+	int ret;
+
+	bus = devm_mdiobus_alloc(&pdev->dev);
+	if (!bus)
+		return -ENOMEM;
+
+	bus->name = TN40_DRV_NAME;
+	bus->parent = &pdev->dev;
+	snprintf(bus->id, MII_BUS_ID_SIZE, "tn40xx-%x-%x",
+		 pci_domain_nr(pdev->bus), pci_dev_id(pdev));
+	bus->priv = priv;
+
+	bus->read_c45 = tn40_mdio_read_cb;
+	bus->write_c45 = tn40_mdio_write_cb;
+
+	ret = devm_mdiobus_register(&pdev->dev, bus);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register mdiobus %d %u %u\n",
+			ret, bus->state, MDIOBUS_UNREGISTERED);
+		return ret;
+	}
+	tn40_mdio_set_speed(priv, TN40_MDIO_SPEED_6MHZ);
+	priv->mdio = bus;
+	return 0;
+}