[PATCH] phylib: add mdio-gpio bus driver (v3)

[PATCH] phylib: add mdio-gpio bus driver (v3)

[Paulius Zaleckas]

Useful for machines where PHY control is connected to GPIO.
This driver also supports interrupts from PHY.

Changes since v2:
- add module author, description and license
- add module alias for udev
- rename mdc and mdio function (were ugly names)
- don't BUG kernel if phy address is invalid
- change MII to MDIO in name
- add __init __exit to module loading functions
- some cosmetic changes

Changes since v1:
- fixed releasing of gpio (thanks to Sascha Hauer)
- fixed compiling due to bus->dev to bus->parent change

Signed-off-by: Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
---

 drivers/net/phy/Kconfig     |    9 ++
 drivers/net/phy/Makefile    |    1 
 drivers/net/phy/mdio-gpio.c |  200 +++++++++++++++++++++++++++++++++++++++++++
 include/linux/mdio-gpio.h   |   40 +++++++++
 4 files changed, 250 insertions(+), 0 deletions(-)
 create mode 100644 drivers/net/phy/mdio-gpio.c
 create mode 100644 include/linux/mdio-gpio.h


diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
index d55932a..610fd88 100644
--- a/drivers/net/phy/Kconfig
+++ b/drivers/net/phy/Kconfig
@@ -84,6 +84,15 @@ config MDIO_BITBANG
 
 	  If in doubt, say N.
 
+config MDIO_GPIO
+	tristate "Support for GPIO bitbanged MDIO buses"
+	depends on MDIO_BITBANG && GENERIC_GPIO
+	help
+	  Supports MDIO busses connected to GPIO.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called mdio-gpio.
+
 config MDIO_OF_GPIO
 	tristate "Support for GPIO lib-based bitbanged MDIO buses"
 	depends on MDIO_BITBANG && OF_GPIO
diff --git a/drivers/net/phy/Makefile b/drivers/net/phy/Makefile
index eee329f..8629b09 100644
--- a/drivers/net/phy/Makefile
+++ b/drivers/net/phy/Makefile
@@ -15,4 +15,5 @@ obj-$(CONFIG_ICPLUS_PHY)	+= icplus.o
 obj-$(CONFIG_REALTEK_PHY)	+= realtek.o
 obj-$(CONFIG_FIXED_PHY)		+= fixed.o
 obj-$(CONFIG_MDIO_BITBANG)	+= mdio-bitbang.o
+obj-$(CONFIG_MDIO_GPIO)		+= mdio-gpio.o
 obj-$(CONFIG_MDIO_OF_GPIO)	+= mdio-ofgpio.o
diff --git a/drivers/net/phy/mdio-gpio.c b/drivers/net/phy/mdio-gpio.c
new file mode 100644
index 0000000..c860468
--- /dev/null
+++ b/drivers/net/phy/mdio-gpio.c
@@ -0,0 +1,200 @@
+/*
+ * GPIO based MDIO bitbang driver.
+ *
+ * Copyright (C) 2008, Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
+ *
+ * Based on mdio-ofgpio.c:
+ *
+ * Copyright (c) 2008 CSE Semaphore Belgium.
+ *  by Laurent Pinchart <laurentp@cse-semaphore.com>
+ *
+ * Copyright (c) 2003 Intracom S.A.
+ *  by Pantelis Antoniou <panto@intracom.gr>
+ *
+ * 2005 (c) MontaVista Software, Inc.
+ * Vitaly Bordug <vbordug@ru.mvista.com>
+ *
+ * This file is licensed under the terms of the GNU General Public License
+ * version 2. This program is licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/gpio.h>
+#include <linux/mdio-bitbang.h>
+#include <linux/mdio-gpio.h>
+
+struct mdio_gpio_info {
+	struct mdiobb_ctrl ctrl;
+	unsigned int mdc, mdio;
+};
+
+static void mdio_dir(struct mdiobb_ctrl *ctrl, int dir)
+{
+	struct mdio_gpio_info *bitbang =
+		container_of(ctrl, struct mdio_gpio_info, ctrl);
+
+	if (dir)
+		gpio_direction_output(bitbang->mdio, 1);
+	else
+		gpio_direction_input(bitbang->mdio);
+}
+
+static int mdio_get(struct mdiobb_ctrl *ctrl)
+{
+	struct mdio_gpio_info *bitbang =
+		container_of(ctrl, struct mdio_gpio_info, ctrl);
+
+	return gpio_get_value(bitbang->mdio);
+}
+
+static void mdio_set(struct mdiobb_ctrl *ctrl, int what)
+{
+	struct mdio_gpio_info *bitbang =
+		container_of(ctrl, struct mdio_gpio_info, ctrl);
+
+	gpio_set_value(bitbang->mdio, what);
+}
+
+static void mdc_set(struct mdiobb_ctrl *ctrl, int what)
+{
+	struct mdio_gpio_info *bitbang =
+		container_of(ctrl, struct mdio_gpio_info, ctrl);
+
+	gpio_set_value(bitbang->mdc, what);
+}
+
+static struct mdiobb_ops mdio_gpio_ops = {
+	.owner = THIS_MODULE,
+	.set_mdc = mdc_set,
+	.set_mdio_dir = mdio_dir,
+	.set_mdio_data = mdio_set,
+	.get_mdio_data = mdio_get,
+};
+
+static int __devinit mdio_gpio_probe(struct platform_device *pdev)
+{
+	struct mii_bus *new_bus;
+	struct mdio_gpio_info *bitbang;
+	struct mdio_gpio_platform_data *pdata;
+	int ret = -ENOMEM;
+	int i;
+
+	pdata = pdev->dev.platform_data;
+	if (pdata == NULL)
+		goto out;
+
+	bitbang = kzalloc(sizeof(*bitbang), GFP_KERNEL);
+	if (!bitbang)
+		goto out;
+
+	bitbang->ctrl.ops = &mdio_gpio_ops;
+	bitbang->mdc = pdata->mdc;
+	bitbang->mdio = pdata->mdio;
+
+	if (gpio_request(bitbang->mdc, "mdc"))
+		goto out_free_bitbang;
+
+	if (gpio_request(bitbang->mdio, "mdio"))
+		goto out_free_mdc;
+
+	new_bus = alloc_mdio_bitbang(&bitbang->ctrl);
+	if (!new_bus)
+		goto out_free_gpio;
+
+	new_bus->name = "GPIO Bitbanged MDIO",
+	snprintf(new_bus->id, MII_BUS_ID_SIZE, "phy%i", pdev->id);
+
+	new_bus->phy_mask = ~0;
+	new_bus->irq = kmalloc(sizeof(int) * PHY_MAX_ADDR, GFP_KERNEL);
+	if (!new_bus->irq)
+		goto out_free_bus;
+
+	for (i = 0; i < PHY_MAX_ADDR; i++)
+		new_bus->irq[i] = PHY_POLL;
+
+	for (i = 0; i < pdata->nr_phys; i++) {
+		unsigned int phy_addr = pdata->phys[i].addr;
+
+		if (phy_addr >= PHY_MAX_ADDR) {
+			dev_err(&pdev->dev,
+				"Failed to add phy with invalid address: 0x%x",
+				phy_addr);
+			continue;
+		}
+
+		new_bus->phy_mask &= ~(1 << phy_addr);
+		new_bus->irq[phy_addr] = pdata->phys[i].irq;
+	}
+
+	if (new_bus->phy_mask == ~0)
+		goto out_free_irq;
+
+	new_bus->parent = &pdev->dev;
+	platform_set_drvdata(pdev, new_bus);
+
+	ret = mdiobus_register(new_bus);
+	if (ret)
+		goto out_free_all;
+
+	return 0;
+
+out_free_all:
+	platform_set_drvdata(pdev, NULL);
+out_free_irq:
+	kfree(new_bus->irq);
+out_free_bus:
+	free_mdio_bitbang(new_bus);
+out_free_gpio:
+	gpio_free(bitbang->mdio);
+out_free_mdc:
+	gpio_free(bitbang->mdc);
+out_free_bitbang:
+	kfree(bitbang);
+out:
+	return ret;
+}
+
+static int __devexit mdio_gpio_remove(struct platform_device *pdev)
+{
+	struct mii_bus *bus = platform_get_drvdata(pdev);
+	struct mdio_gpio_info *bitbang = bus->priv;
+
+	mdiobus_unregister(bus);
+	kfree(bus->irq);
+	free_mdio_bitbang(bus);
+	platform_set_drvdata(pdev, NULL);
+	gpio_free(bitbang->mdc);
+	gpio_free(bitbang->mdio);
+	kfree(bitbang);
+
+	return 0;
+}
+
+static struct platform_driver mdio_gpio_driver = {
+	.probe = mdio_gpio_probe,
+	.remove = __devexit_p(mdio_gpio_remove),
+	.driver		= {
+		.name	= "mdio-gpio",
+		.owner	= THIS_MODULE,
+	},
+};
+
+static int __init mdio_gpio_init(void)
+{
+	return platform_driver_register(&mdio_gpio_driver);
+}
+module_init(mdio_gpio_init);
+
+static void __exit mdio_gpio_exit(void)
+{
+	platform_driver_unregister(&mdio_gpio_driver);
+}
+module_exit(mdio_gpio_exit);
+
+MODULE_ALIAS("platform:mdio-gpio");
+MODULE_AUTHOR("Paulius Zaleckas <paulius.zaleckas@teltonika.lt>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Generic driver for MDIO bus emulation using GPIO");
diff --git a/include/linux/mdio-gpio.h b/include/linux/mdio-gpio.h
new file mode 100644
index 0000000..82d5fa4
--- /dev/null
+++ b/include/linux/mdio-gpio.h
@@ -0,0 +1,40 @@
+/*
+ * MDIO-GPIO bus platform data structures
+ *
+ * Copyright (C) 2008, Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#ifndef __LINUX_MDIO_GPIO_H
+#define __LINUX_MDIO_GPIO_H
+
+struct mdio_gpio_phy {
+	/* PHY address on MDIO bus */
+	unsigned int addr;
+	/* preconfigured irq connected to PHY or -1 if no irq */
+	int irq;
+};
+
+struct mdio_gpio_platform_data {
+	/* GPIO numbers for bus pins */
+	unsigned int mdc;
+	unsigned int mdio;
+
+	unsigned int nr_phys;
+	struct mdio_gpio_phy *phys;
+};
+
+#endif /* __LINUX_MDIO_GPIO_H */

Re: [PATCH] phylib: add mdio-gpio bus driver (v3)

[Mike Frysinger]

On Tue, Oct 28, 2008 at 06:35, Paulius Zaleckas wrote:
> +config MDIO_GPIO
> +       tristate "Support for GPIO bitbanged MDIO buses"
>  config MDIO_OF_GPIO
>        tristate "Support for GPIO lib-based bitbanged MDIO buses"

seems to me these drivers have the same description ...

> +++ b/include/linux/mdio-gpio.h
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

this is why short GPL notices are nice ... you dont end up with
outdated contact information like this ...
-mike

Re: [PATCH] phylib: add mdio-gpio bus driver (v3)

[Paulius Zaleckas]

Mike Frysinger wrote:
> On Tue, Oct 28, 2008 at 06:35, Paulius Zaleckas wrote:
>> +config MDIO_GPIO
>> +       tristate "Support for GPIO bitbanged MDIO buses"
>>  config MDIO_OF_GPIO
>>        tristate "Support for GPIO lib-based bitbanged MDIO buses"
> 
> seems to me these drivers have the same description ...

Yes... but it is MDIO_OF_GPIO description that needs changing...
Should I make patch for it?

>> +++ b/include/linux/mdio-gpio.h
>> + * You should have received a copy of the GNU General Public License
>> + * along with this program; if not, write to the Free Software
>> + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
> 
> this is why short GPL notices are nice ... you dont end up with
> outdated contact information like this ...

It came from mdio-ofgpio driver... If you can mail suitable short GPL notice
I will put it there instead of updating address.

> -mike

Re: [PATCH] phylib: add mdio-gpio bus driver (v3)

[Grant Likely]

On Tue, Oct 28, 2008 at 5:31 AM, Paulius Zaleckas
<paulius.zaleckas@teltonika.lt> wrote:
> Mike Frysinger wrote:
>> On Tue, Oct 28, 2008 at 06:35, Paulius Zaleckas wrote:
>>> +config MDIO_GPIO
>>> +       tristate "Support for GPIO bitbanged MDIO buses"
>>>  config MDIO_OF_GPIO
>>>        tristate "Support for GPIO lib-based bitbanged MDIO buses"
>>
>> seems to me these drivers have the same description ...
>
> Yes... but it is MDIO_OF_GPIO description that needs changing...
> Should I make patch for it?

Wait a minute....  This is the same driver and it's just been
duplicated.  NAK.  Please don't do this.  Instead add a platform bus
binding to the existing driver.  Most of the code can be shared.

Cheers,
g.

-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.

Re: [PATCH] phylib: add mdio-gpio bus driver (v3)

[Paulius Zaleckas]

Grant Likely wrote:
> On Tue, Oct 28, 2008 at 5:31 AM, Paulius Zaleckas
> <paulius.zaleckas@teltonika.lt> wrote:
>> Mike Frysinger wrote:
>>> On Tue, Oct 28, 2008 at 06:35, Paulius Zaleckas wrote:
>>>> +config MDIO_GPIO
>>>> +       tristate "Support for GPIO bitbanged MDIO buses"
>>>>  config MDIO_OF_GPIO
>>>>        tristate "Support for GPIO lib-based bitbanged MDIO buses"
>>> seems to me these drivers have the same description ...
>> Yes... but it is MDIO_OF_GPIO description that needs changing...
>> Should I make patch for it?
> 
> Wait a minute....  This is the same driver and it's just been
> duplicated.  NAK.  Please don't do this.  Instead add a platform bus
> binding to the existing driver.  Most of the code can be shared.

It is very similar. If highly #ifdef'ed driver is OK then I can merge
these driver to single one, but mdio-ofgpio driver name will have to
change to mdio-gpio. OK?

Re: [PATCH] phylib: add mdio-gpio bus driver (v3)

[Grant Likely]

On Wed, Oct 29, 2008 at 2:44 AM, Paulius Zaleckas
<paulius.zaleckas@teltonika.lt> wrote:
> Grant Likely wrote:
>> On Tue, Oct 28, 2008 at 5:31 AM, Paulius Zaleckas
>> <paulius.zaleckas@teltonika.lt> wrote:
>>> Mike Frysinger wrote:
>>>> On Tue, Oct 28, 2008 at 06:35, Paulius Zaleckas wrote:
>>>>> +config MDIO_GPIO
>>>>> +       tristate "Support for GPIO bitbanged MDIO buses"
>>>>>  config MDIO_OF_GPIO
>>>>>        tristate "Support for GPIO lib-based bitbanged MDIO buses"
>>>> seems to me these drivers have the same description ...
>>> Yes... but it is MDIO_OF_GPIO description that needs changing...
>>> Should I make patch for it?
>>
>> Wait a minute....  This is the same driver and it's just been
>> duplicated.  NAK.  Please don't do this.  Instead add a platform bus
>> binding to the existing driver.  Most of the code can be shared.
>
> It is very similar. If highly #ifdef'ed driver is OK then I can merge
> these driver to single one, but mdio-ofgpio driver name will have to
> change to mdio-gpio. OK?

Absolutely, change the name.  Also, I don't think you'll need as many
#ifdefs as you fear you do.  :-)  Mostly you'll need two #ifdef
sections; one for the of_platform binding and one for the platform
binding.  drivers/video/xilinxfb.c is a good example of how to do it.

g.

-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.