diff mbox series

[v2,1/3] net: phy: mdio: add IPQ40xx MDIO driver

Message ID 20200414181012.114905-1-robert.marko@sartura.hr (mailing list archive)
State Superseded
Headers show
Series [v2,1/3] net: phy: mdio: add IPQ40xx MDIO driver | expand

Commit Message

Robert Marko April 14, 2020, 6:10 p.m. UTC
This patch adds the driver for the MDIO interface
inside of Qualcomm IPQ40xx series SoC-s.

Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
Signed-off-by: Robert Marko <robert.marko@sartura.hr>
Cc: Luka Perkov <luka.perkov@sartura.hr>
---
Changes from v1 to v2:
* Remove magic default value
* Remove lockdep_assert_held
* Add C45 check
* Simplify the driver
* Drop device and mii_bus structs from private struct
* Use devm_mdiobus_alloc_size()

 drivers/net/phy/Kconfig        |   7 ++
 drivers/net/phy/Makefile       |   1 +
 drivers/net/phy/mdio-ipq40xx.c | 176 +++++++++++++++++++++++++++++++++
 3 files changed, 184 insertions(+)
 create mode 100644 drivers/net/phy/mdio-ipq40xx.c

Comments

Andrew Lunn April 14, 2020, 6:43 p.m. UTC | #1
Hi Robert

This is looking better

> +#include <linux/delay.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>

I don't think you need this header. There are no mutexes here.

> +#include <linux/io.h>
> +#include <linux/of_address.h>
> +#include <linux/of_mdio.h>
> +#include <linux/phy.h>
> +#include <linux/platform_device.h>
> +
> +#define MDIO_CTRL_0_REG		0x40
> +#define MDIO_CTRL_1_REG		0x44
> +#define MDIO_CTRL_2_REG		0x48
> +#define MDIO_CTRL_3_REG		0x4c
> +#define MDIO_CTRL_4_REG		0x50

So your next version will hopefully have better names.

> +static int ipq40xx_mdio_wait_busy(struct mii_bus *bus)
> +{
> +	struct ipq40xx_mdio_data *priv = bus->priv;
> +	int i;
> +
> +	for (i = 0; i < IPQ40XX_MDIO_RETRY; i++) {
> +		unsigned int busy;
> +
> +		busy = readl(priv->membase + MDIO_CTRL_4_REG) &
> +			MDIO_CTRL_4_ACCESS_BUSY;
> +		if (!busy)
> +			return 0;
> +
> +		/* BUSY might take to be cleard by 15~20 times of loop */
> +		udelay(IPQ40XX_MDIO_DELAY);
> +	}
> +
> +	dev_err(bus->parent, "MDIO operation timed out\n");
> +
> +	return -ETIMEDOUT;
> +}

You can probably make use of include/linux/iopoll.h 

    Andrew
Florian Fainelli April 14, 2020, 9:17 p.m. UTC | #2
On 4/14/2020 11:10 AM, Robert Marko wrote:
> This patch adds the driver for the MDIO interface
> inside of Qualcomm IPQ40xx series SoC-s.
> 
> Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
> Signed-off-by: Robert Marko <robert.marko@sartura.hr>
> Cc: Luka Perkov <luka.perkov@sartura.hr>
> ---
> Changes from v1 to v2:
> * Remove magic default value
> * Remove lockdep_assert_held
> * Add C45 check
> * Simplify the driver
> * Drop device and mii_bus structs from private struct
> * Use devm_mdiobus_alloc_size()
> 
>  drivers/net/phy/Kconfig        |   7 ++
>  drivers/net/phy/Makefile       |   1 +
>  drivers/net/phy/mdio-ipq40xx.c | 176 +++++++++++++++++++++++++++++++++
>  3 files changed, 184 insertions(+)
>  create mode 100644 drivers/net/phy/mdio-ipq40xx.c
> 
> diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
> index 3fa33d27eeba..815d52fa6080 100644
> --- a/drivers/net/phy/Kconfig
> +++ b/drivers/net/phy/Kconfig
> @@ -157,6 +157,13 @@ config MDIO_I2C
>  
>  	  This is library mode.
>  
> +config MDIO_IPQ40XX
> +	tristate "Qualcomm IPQ40xx MDIO interface"
> +	depends on HAS_IOMEM && OF

You can drop the OF dependency here, of_mdiobus_register() becomes
mdiobus_register() with CONFIG_OF=n.

[snip]

> +static int ipq40xx_mdio_wait_busy(struct mii_bus *bus)
> +{
> +	struct ipq40xx_mdio_data *priv = bus->priv;
> +	int i;
> +
> +	for (i = 0; i < IPQ40XX_MDIO_RETRY; i++) {
> +		unsigned int busy;
> +
> +		busy = readl(priv->membase + MDIO_CTRL_4_REG) &
> +			MDIO_CTRL_4_ACCESS_BUSY;
> +		if (!busy)
> +			return 0;
> +
> +		/* BUSY might take to be cleard by 15~20 times of loop */

typo: cleard instead of cleared.

> +		udelay(IPQ40XX_MDIO_DELAY);
> +	}

consider using readl_poll_timeout() for this loop.

With that fixed:

Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Russell King (Oracle) April 15, 2020, 9:33 a.m. UTC | #3
On Tue, Apr 14, 2020 at 08:10:11PM +0200, Robert Marko wrote:
> diff --git a/drivers/net/phy/mdio-ipq40xx.c b/drivers/net/phy/mdio-ipq40xx.c
> new file mode 100644
> index 000000000000..d8c11c621f20
> --- /dev/null
> +++ b/drivers/net/phy/mdio-ipq40xx.c
> @@ -0,0 +1,176 @@
> +// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
> +/* Copyright (c) 2015, The Linux Foundation. All rights reserved. */
> +/* Copyright (c) 2020 Sartura Ltd. */
> +
> +#include <linux/delay.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/io.h>
> +#include <linux/of_address.h>
> +#include <linux/of_mdio.h>
> +#include <linux/phy.h>
> +#include <linux/platform_device.h>
> +

Looking at how these registers are used, they could be renamed:

> +#define MDIO_CTRL_0_REG		0x40

This seems to be unused.

> +#define MDIO_CTRL_1_REG		0x44

MDIO_ADDR_REG

> +#define MDIO_CTRL_2_REG		0x48

MDIO_DATA_WRITE_REG

> +#define MDIO_CTRL_3_REG		0x4c

MDIO_DATA_READ_REG

> +#define MDIO_CTRL_4_REG		0x50
> +#define MDIO_CTRL_4_ACCESS_BUSY		BIT(16)
> +#define MDIO_CTRL_4_ACCESS_START		BIT(8)
> +#define MDIO_CTRL_4_ACCESS_CODE_READ		0
> +#define MDIO_CTRL_4_ACCESS_CODE_WRITE	1

MDIO_CMD_* ?

> +
> +#define IPQ40XX_MDIO_RETRY	1000
> +#define IPQ40XX_MDIO_DELAY	10
> +
> +struct ipq40xx_mdio_data {
> +	void __iomem	*membase;
> +};
> +
> +static int ipq40xx_mdio_wait_busy(struct mii_bus *bus)
> +{
> +	struct ipq40xx_mdio_data *priv = bus->priv;
> +	int i;
> +
> +	for (i = 0; i < IPQ40XX_MDIO_RETRY; i++) {
> +		unsigned int busy;
> +
> +		busy = readl(priv->membase + MDIO_CTRL_4_REG) &
> +			MDIO_CTRL_4_ACCESS_BUSY;
> +		if (!busy)
> +			return 0;
> +
> +		/* BUSY might take to be cleard by 15~20 times of loop */
> +		udelay(IPQ40XX_MDIO_DELAY);
> +	}
> +
> +	dev_err(bus->parent, "MDIO operation timed out\n");
> +
> +	return -ETIMEDOUT;
> +}
> +
> +static int ipq40xx_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
> +{
> +	struct ipq40xx_mdio_data *priv = bus->priv;
> +	int value = 0;
> +	unsigned int cmd = 0;

No need to initialise either of these, and you can eliminate "value"
which will then satisfy davem's requirement for reverse-christmas-tree
ordering of variable declarations.

> +
> +	/* Reject clause 45 */
> +	if (regnum & MII_ADDR_C45)
> +		return -EOPNOTSUPP;
> +
> +	if (ipq40xx_mdio_wait_busy(bus))
> +		return -ETIMEDOUT;
> +
> +	/* issue the phy address and reg */
> +	writel((mii_id << 8) | regnum, priv->membase + MDIO_CTRL_1_REG);
> +
> +	cmd = MDIO_CTRL_4_ACCESS_START | MDIO_CTRL_4_ACCESS_CODE_READ;
> +
> +	/* issue read command */
> +	writel(cmd, priv->membase + MDIO_CTRL_4_REG);
> +
> +	/* Wait read complete */
> +	if (ipq40xx_mdio_wait_busy(bus))
> +		return -ETIMEDOUT;
> +
> +	/* Read data */
> +	value = readl(priv->membase + MDIO_CTRL_3_REG);
> +
> +	return value;
> +}
> +
> +static int ipq40xx_mdio_write(struct mii_bus *bus, int mii_id, int regnum,
> +							 u16 value)
> +{
> +	struct ipq40xx_mdio_data *priv = bus->priv;
> +	unsigned int cmd = 0;

No need to initialise cmd.
Robert Marko April 15, 2020, 3:07 p.m. UTC | #4
I have sent a v3.

I tried to incorporate all of your remarks there.

Thanks
Robert

On Wed, Apr 15, 2020 at 11:33 AM Russell King - ARM Linux admin
<linux@armlinux.org.uk> wrote:
>
> On Tue, Apr 14, 2020 at 08:10:11PM +0200, Robert Marko wrote:
> > diff --git a/drivers/net/phy/mdio-ipq40xx.c b/drivers/net/phy/mdio-ipq40xx.c
> > new file mode 100644
> > index 000000000000..d8c11c621f20
> > --- /dev/null
> > +++ b/drivers/net/phy/mdio-ipq40xx.c
> > @@ -0,0 +1,176 @@
> > +// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
> > +/* Copyright (c) 2015, The Linux Foundation. All rights reserved. */
> > +/* Copyright (c) 2020 Sartura Ltd. */
> > +
> > +#include <linux/delay.h>
> > +#include <linux/kernel.h>
> > +#include <linux/module.h>
> > +#include <linux/mutex.h>
> > +#include <linux/io.h>
> > +#include <linux/of_address.h>
> > +#include <linux/of_mdio.h>
> > +#include <linux/phy.h>
> > +#include <linux/platform_device.h>
> > +
>
> Looking at how these registers are used, they could be renamed:
>
> > +#define MDIO_CTRL_0_REG              0x40
>
> This seems to be unused.
>
> > +#define MDIO_CTRL_1_REG              0x44
>
> MDIO_ADDR_REG
>
> > +#define MDIO_CTRL_2_REG              0x48
>
> MDIO_DATA_WRITE_REG
>
> > +#define MDIO_CTRL_3_REG              0x4c
>
> MDIO_DATA_READ_REG
>
> > +#define MDIO_CTRL_4_REG              0x50
> > +#define MDIO_CTRL_4_ACCESS_BUSY              BIT(16)
> > +#define MDIO_CTRL_4_ACCESS_START             BIT(8)
> > +#define MDIO_CTRL_4_ACCESS_CODE_READ         0
> > +#define MDIO_CTRL_4_ACCESS_CODE_WRITE        1
>
> MDIO_CMD_* ?
>
> > +
> > +#define IPQ40XX_MDIO_RETRY   1000
> > +#define IPQ40XX_MDIO_DELAY   10
> > +
> > +struct ipq40xx_mdio_data {
> > +     void __iomem    *membase;
> > +};
> > +
> > +static int ipq40xx_mdio_wait_busy(struct mii_bus *bus)
> > +{
> > +     struct ipq40xx_mdio_data *priv = bus->priv;
> > +     int i;
> > +
> > +     for (i = 0; i < IPQ40XX_MDIO_RETRY; i++) {
> > +             unsigned int busy;
> > +
> > +             busy = readl(priv->membase + MDIO_CTRL_4_REG) &
> > +                     MDIO_CTRL_4_ACCESS_BUSY;
> > +             if (!busy)
> > +                     return 0;
> > +
> > +             /* BUSY might take to be cleard by 15~20 times of loop */
> > +             udelay(IPQ40XX_MDIO_DELAY);
> > +     }
> > +
> > +     dev_err(bus->parent, "MDIO operation timed out\n");
> > +
> > +     return -ETIMEDOUT;
> > +}
> > +
> > +static int ipq40xx_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
> > +{
> > +     struct ipq40xx_mdio_data *priv = bus->priv;
> > +     int value = 0;
> > +     unsigned int cmd = 0;
>
> No need to initialise either of these, and you can eliminate "value"
> which will then satisfy davem's requirement for reverse-christmas-tree
> ordering of variable declarations.
>
> > +
> > +     /* Reject clause 45 */
> > +     if (regnum & MII_ADDR_C45)
> > +             return -EOPNOTSUPP;
> > +
> > +     if (ipq40xx_mdio_wait_busy(bus))
> > +             return -ETIMEDOUT;
> > +
> > +     /* issue the phy address and reg */
> > +     writel((mii_id << 8) | regnum, priv->membase + MDIO_CTRL_1_REG);
> > +
> > +     cmd = MDIO_CTRL_4_ACCESS_START | MDIO_CTRL_4_ACCESS_CODE_READ;
> > +
> > +     /* issue read command */
> > +     writel(cmd, priv->membase + MDIO_CTRL_4_REG);
> > +
> > +     /* Wait read complete */
> > +     if (ipq40xx_mdio_wait_busy(bus))
> > +             return -ETIMEDOUT;
> > +
> > +     /* Read data */
> > +     value = readl(priv->membase + MDIO_CTRL_3_REG);
> > +
> > +     return value;
> > +}
> > +
> > +static int ipq40xx_mdio_write(struct mii_bus *bus, int mii_id, int regnum,
> > +                                                      u16 value)
> > +{
> > +     struct ipq40xx_mdio_data *priv = bus->priv;
> > +     unsigned int cmd = 0;
>
> No need to initialise cmd.
>
> --
> RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
> FTTC broadband for 0.8mile line in suburbia: sync at 10.2Mbps down 587kbps up
diff mbox series

Patch

diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
index 3fa33d27eeba..815d52fa6080 100644
--- a/drivers/net/phy/Kconfig
+++ b/drivers/net/phy/Kconfig
@@ -157,6 +157,13 @@  config MDIO_I2C
 
 	  This is library mode.
 
+config MDIO_IPQ40XX
+	tristate "Qualcomm IPQ40xx MDIO interface"
+	depends on HAS_IOMEM && OF
+	help
+	  This driver supports the MDIO interface found in Qualcomm
+	  IPQ40xx series Soc-s.
+
 config MDIO_IPQ8064
 	tristate "Qualcomm IPQ8064 MDIO interface support"
 	depends on HAS_IOMEM && OF_MDIO
diff --git a/drivers/net/phy/Makefile b/drivers/net/phy/Makefile
index 2f5c7093a65b..36aafc6128c4 100644
--- a/drivers/net/phy/Makefile
+++ b/drivers/net/phy/Makefile
@@ -37,6 +37,7 @@  obj-$(CONFIG_MDIO_CAVIUM)	+= mdio-cavium.o
 obj-$(CONFIG_MDIO_GPIO)		+= mdio-gpio.o
 obj-$(CONFIG_MDIO_HISI_FEMAC)	+= mdio-hisi-femac.o
 obj-$(CONFIG_MDIO_I2C)		+= mdio-i2c.o
+obj-$(CONFIG_MDIO_IPQ40XX)	+= mdio-ipq40xx.o
 obj-$(CONFIG_MDIO_IPQ8064)	+= mdio-ipq8064.o
 obj-$(CONFIG_MDIO_MOXART)	+= mdio-moxart.o
 obj-$(CONFIG_MDIO_MSCC_MIIM)	+= mdio-mscc-miim.o
diff --git a/drivers/net/phy/mdio-ipq40xx.c b/drivers/net/phy/mdio-ipq40xx.c
new file mode 100644
index 000000000000..d8c11c621f20
--- /dev/null
+++ b/drivers/net/phy/mdio-ipq40xx.c
@@ -0,0 +1,176 @@ 
+// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+/* Copyright (c) 2015, The Linux Foundation. All rights reserved. */
+/* Copyright (c) 2020 Sartura Ltd. */
+
+#include <linux/delay.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/io.h>
+#include <linux/of_address.h>
+#include <linux/of_mdio.h>
+#include <linux/phy.h>
+#include <linux/platform_device.h>
+
+#define MDIO_CTRL_0_REG		0x40
+#define MDIO_CTRL_1_REG		0x44
+#define MDIO_CTRL_2_REG		0x48
+#define MDIO_CTRL_3_REG		0x4c
+#define MDIO_CTRL_4_REG		0x50
+#define MDIO_CTRL_4_ACCESS_BUSY		BIT(16)
+#define MDIO_CTRL_4_ACCESS_START		BIT(8)
+#define MDIO_CTRL_4_ACCESS_CODE_READ		0
+#define MDIO_CTRL_4_ACCESS_CODE_WRITE	1
+
+#define IPQ40XX_MDIO_RETRY	1000
+#define IPQ40XX_MDIO_DELAY	10
+
+struct ipq40xx_mdio_data {
+	void __iomem	*membase;
+};
+
+static int ipq40xx_mdio_wait_busy(struct mii_bus *bus)
+{
+	struct ipq40xx_mdio_data *priv = bus->priv;
+	int i;
+
+	for (i = 0; i < IPQ40XX_MDIO_RETRY; i++) {
+		unsigned int busy;
+
+		busy = readl(priv->membase + MDIO_CTRL_4_REG) &
+			MDIO_CTRL_4_ACCESS_BUSY;
+		if (!busy)
+			return 0;
+
+		/* BUSY might take to be cleard by 15~20 times of loop */
+		udelay(IPQ40XX_MDIO_DELAY);
+	}
+
+	dev_err(bus->parent, "MDIO operation timed out\n");
+
+	return -ETIMEDOUT;
+}
+
+static int ipq40xx_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
+{
+	struct ipq40xx_mdio_data *priv = bus->priv;
+	int value = 0;
+	unsigned int cmd = 0;
+
+	/* Reject clause 45 */
+	if (regnum & MII_ADDR_C45)
+		return -EOPNOTSUPP;
+
+	if (ipq40xx_mdio_wait_busy(bus))
+		return -ETIMEDOUT;
+
+	/* issue the phy address and reg */
+	writel((mii_id << 8) | regnum, priv->membase + MDIO_CTRL_1_REG);
+
+	cmd = MDIO_CTRL_4_ACCESS_START | MDIO_CTRL_4_ACCESS_CODE_READ;
+
+	/* issue read command */
+	writel(cmd, priv->membase + MDIO_CTRL_4_REG);
+
+	/* Wait read complete */
+	if (ipq40xx_mdio_wait_busy(bus))
+		return -ETIMEDOUT;
+
+	/* Read data */
+	value = readl(priv->membase + MDIO_CTRL_3_REG);
+
+	return value;
+}
+
+static int ipq40xx_mdio_write(struct mii_bus *bus, int mii_id, int regnum,
+							 u16 value)
+{
+	struct ipq40xx_mdio_data *priv = bus->priv;
+	unsigned int cmd = 0;
+
+	/* Reject clause 45 */
+	if (regnum & MII_ADDR_C45)
+		return -EOPNOTSUPP;
+
+	if (ipq40xx_mdio_wait_busy(bus))
+		return -ETIMEDOUT;
+
+	/* issue the phy address and reg */
+	writel((mii_id << 8) | regnum, priv->membase + MDIO_CTRL_1_REG);
+
+	/* issue write data */
+	writel(value, priv->membase + MDIO_CTRL_2_REG);
+
+	cmd = MDIO_CTRL_4_ACCESS_START | MDIO_CTRL_4_ACCESS_CODE_WRITE;
+	/* issue write command */
+	writel(cmd, priv->membase + MDIO_CTRL_4_REG);
+
+	/* Wait write complete */
+	if (ipq40xx_mdio_wait_busy(bus))
+		return -ETIMEDOUT;
+
+	return 0;
+}
+
+static int ipq40xx_mdio_probe(struct platform_device *pdev)
+{
+	struct ipq40xx_mdio_data *priv;
+	struct mii_bus *bus;
+	int ret;
+
+	bus = devm_mdiobus_alloc_size(&pdev->dev, sizeof(*priv));
+	if (!bus)
+		return -ENOMEM;
+
+	priv = bus->priv;
+
+	priv->membase = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(priv->membase))
+		return PTR_ERR(priv->membase);
+
+	bus->name = "ipq40xx_mdio";
+	bus->read = ipq40xx_mdio_read;
+	bus->write = ipq40xx_mdio_write;
+	bus->parent = &pdev->dev;
+	snprintf(bus->id, MII_BUS_ID_SIZE, "%s%d", pdev->name, pdev->id);
+
+	ret = of_mdiobus_register(bus, pdev->dev.of_node);
+	if (ret) {
+		dev_err(&pdev->dev, "Cannot register MDIO bus!\n");
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, bus);
+
+	return 0;
+}
+
+static int ipq40xx_mdio_remove(struct platform_device *pdev)
+{
+	struct mii_bus *bus = platform_get_drvdata(pdev);
+
+	mdiobus_unregister(bus);
+
+	return 0;
+}
+
+static const struct of_device_id ipq40xx_mdio_dt_ids[] = {
+	{ .compatible = "qcom,ipq40xx-mdio" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ipq40xx_mdio_dt_ids);
+
+static struct platform_driver ipq40xx_mdio_driver = {
+	.probe = ipq40xx_mdio_probe,
+	.remove = ipq40xx_mdio_remove,
+	.driver = {
+		.name = "ipq40xx-mdio",
+		.of_match_table = ipq40xx_mdio_dt_ids,
+	},
+};
+
+module_platform_driver(ipq40xx_mdio_driver);
+
+MODULE_DESCRIPTION("IPQ40XX MDIO interface driver");
+MODULE_AUTHOR("Qualcomm Atheros");
+MODULE_LICENSE("Dual BSD/GPL");