diff mbox

[v4,1/2] ohci-platform: Add support for devicetree instantiation

Message ID 1389393980-21183-2-git-send-email-hdegoede@redhat.com
State Superseded, archived
Headers show

Commit Message

Hans de Goede Jan. 10, 2014, 10:46 p.m. UTC
Add support for ohci-platform instantiation from devicetree, including
optionally getting clks and a phy from devicetree, and enabling / disabling
those on power_on / off.

This should allow using ohci-platform from devicetree in various cases.
Specifically after this commit it can be used for the ohci controller found
on Allwinner sunxi SoCs.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 .../devicetree/bindings/usb/mmio-ohci.txt          |  22 +++
 drivers/usb/host/ohci-platform.c                   | 164 ++++++++++++++++++---
 2 files changed, 162 insertions(+), 24 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/usb/mmio-ohci.txt

Comments

Tony Prisk Jan. 11, 2014, 8:37 a.m. UTC | #1
On 11/01/14 11:46, Hans de Goede wrote:
> Add support for ohci-platform instantiation from devicetree, including
> optionally getting clks and a phy from devicetree, and enabling / disabling
> those on power_on / off.
>
> This should allow using ohci-platform from devicetree in various cases.
> Specifically after this commit it can be used for the ohci controller found
> on Allwinner sunxi SoCs.
>
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> ---
>   .../devicetree/bindings/usb/mmio-ohci.txt          |  22 +++
>   drivers/usb/host/ohci-platform.c                   | 164 ++++++++++++++++++---
>   2 files changed, 162 insertions(+), 24 deletions(-)
>   create mode 100644 Documentation/devicetree/bindings/usb/mmio-ohci.txt
>
> diff --git a/Documentation/devicetree/bindings/usb/mmio-ohci.txt b/Documentation/devicetree/bindings/usb/mmio-ohci.txt
> new file mode 100644
> index 0000000..9c776ed
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/usb/mmio-ohci.txt
> @@ -0,0 +1,22 @@
> +Generic MMIO OHCI controller
> +
> +Required properties:
> +- compatible : "mmio-ohci"
> +- reg : ohci controller register range (address and length)
> +- interrupts : ohci controller interrupt
> +
> +Optional properties:
> +- clocks : a list of phandle + clock specifier pairs
> +- phys : phandle + phy specifier pair
> +- phy-names : "usb"
> +
> +Example:
> +
> +	ohci0: ohci@0x01c14400 {
> +		compatible = "mmio-ohci";
> +		reg = <0x01c14400 0x100>;
> +		interrupts = <64>;
> +		clocks = <&usb_clk 6>, <&ahb_gates 2>;
> +		phys = <&usbphy 1>;
> +		phy-names = "usb";
> +	};
>
> ... <snip> ....
>
> @@ -83,17 +156,40 @@ static int ohci_platform_probe(struct platform_device *dev)
>   		return -ENXIO;
>   	}
>   
> +	hcd = usb_create_hcd(&ohci_platform_hc_driver, &dev->dev,
> +			dev_name(&dev->dev));
> +	if (!hcd)
> +		return -ENOMEM;
> +
> +	platform_set_drvdata(dev, hcd);
> +	dev->dev.platform_data = pdata;
> +	priv = hcd_to_ohci_priv(hcd);
> +
> +	if (pdata == &ohci_platform_defaults && dev->dev.of_node) {
> +		priv->phy = devm_phy_get(&dev->dev, "usb");
> +		if (IS_ERR(priv->phy)) {
> +			err = PTR_ERR(priv->phy);
> +			if (err == -EPROBE_DEFER)
> +				goto err_put_hcd;
> +			priv->phy = NULL;
> +		}
> +
> +		for (clk = 0; clk < OHCI_MAX_CLKS; clk++) {
> +			priv->clks[clk] = of_clk_get(dev->dev.of_node, clk);
> +			if (IS_ERR(priv->clks[clk])) {
> +				err = PTR_ERR(priv->clks[clk]);
> +				if (err == -EPROBE_DEFER)
> +					goto err_put_clks;
> +				priv->clks[clk] = NULL;
> +				break;
> +			}
> +		}
> +	}
>

Given that you have limited the clock parsing to OHCI_MAX_CLKS, there 
should be some kind of warning/error message if the DT contains more 
than OHCI_MAX_CLKS - otherwise you have silent failures when the clocks 
aren't configured.

There is also no note in the binding to indicate this limitation and you 
shouldn't expect people writing DT files to go digging through the 
source to check for this.

Regards
Tony P
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Hans de Goede Jan. 12, 2014, 9:17 a.m. UTC | #2
Hi,

Thanks for the review. Note I did my best to ensure my patches
would not break vt8500 support, but if you could run some tests
with them that would be great.

On 01/11/2014 09:37 AM, Tony Prisk wrote:
> On 11/01/14 11:46, Hans de Goede wrote:
>> Add support for ohci-platform instantiation from devicetree, including
>> optionally getting clks and a phy from devicetree, and enabling / disabling
>> those on power_on / off.
>>
>> This should allow using ohci-platform from devicetree in various cases.
>> Specifically after this commit it can be used for the ohci controller found
>> on Allwinner sunxi SoCs.
>>
>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>> ---
>>   .../devicetree/bindings/usb/mmio-ohci.txt          |  22 +++
>>   drivers/usb/host/ohci-platform.c                   | 164 ++++++++++++++++++---
>>   2 files changed, 162 insertions(+), 24 deletions(-)
>>   create mode 100644 Documentation/devicetree/bindings/usb/mmio-ohci.txt
>>
>> diff --git a/Documentation/devicetree/bindings/usb/mmio-ohci.txt b/Documentation/devicetree/bindings/usb/mmio-ohci.txt
>> new file mode 100644
>> index 0000000..9c776ed
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/usb/mmio-ohci.txt
>> @@ -0,0 +1,22 @@
>> +Generic MMIO OHCI controller
>> +
>> +Required properties:
>> +- compatible : "mmio-ohci"
>> +- reg : ohci controller register range (address and length)
>> +- interrupts : ohci controller interrupt
>> +
>> +Optional properties:
>> +- clocks : a list of phandle + clock specifier pairs
>> +- phys : phandle + phy specifier pair
>> +- phy-names : "usb"
>> +
>> +Example:
>> +
>> +    ohci0: ohci@0x01c14400 {
>> +        compatible = "mmio-ohci";
>> +        reg = <0x01c14400 0x100>;
>> +        interrupts = <64>;
>> +        clocks = <&usb_clk 6>, <&ahb_gates 2>;
>> +        phys = <&usbphy 1>;
>> +        phy-names = "usb";
>> +    };
>>
>> ... <snip> ....
>>
>> @@ -83,17 +156,40 @@ static int ohci_platform_probe(struct platform_device *dev)
>>           return -ENXIO;
>>       }
>> +    hcd = usb_create_hcd(&ohci_platform_hc_driver, &dev->dev,
>> +            dev_name(&dev->dev));
>> +    if (!hcd)
>> +        return -ENOMEM;
>> +
>> +    platform_set_drvdata(dev, hcd);
>> +    dev->dev.platform_data = pdata;
>> +    priv = hcd_to_ohci_priv(hcd);
>> +
>> +    if (pdata == &ohci_platform_defaults && dev->dev.of_node) {
>> +        priv->phy = devm_phy_get(&dev->dev, "usb");
>> +        if (IS_ERR(priv->phy)) {
>> +            err = PTR_ERR(priv->phy);
>> +            if (err == -EPROBE_DEFER)
>> +                goto err_put_hcd;
>> +            priv->phy = NULL;
>> +        }
>> +
>> +        for (clk = 0; clk < OHCI_MAX_CLKS; clk++) {
>> +            priv->clks[clk] = of_clk_get(dev->dev.of_node, clk);
>> +            if (IS_ERR(priv->clks[clk])) {
>> +                err = PTR_ERR(priv->clks[clk]);
>> +                if (err == -EPROBE_DEFER)
>> +                    goto err_put_clks;
>> +                priv->clks[clk] = NULL;
>> +                break;
>> +            }
>> +        }
>> +    }
>>
>
> Given that you have limited the clock parsing to OHCI_MAX_CLKS, there should be some kind of warning/error message if the DT contains more than OHCI_MAX_CLKS - otherwise you have silent failures when the clocks aren't configured.

Adding such a test would be non trivial, and is just not worth it IMHO. There is one special case of a controller with 3 clocks,
all others have 0-2 clocks, there are 0 known controllers with > 3 clocks. And if one shows up then the person writing the
dts will figure this out quickly enough, and using old kernels with newer dts files has never been a supported scenario.

> There is also no note in the binding to indicate this limitation and you shouldn't expect people writing DT files to go digging through the source to check for this.

I've been told by several people that dt-binding documentation should never contain implementation details, since it
is supposed to be platform agnostic, etc. So people writing dts files who need to know implementation details, are
actually expected to look into the implementation. And in my experience with re-using some existing drivers for
other SoC's, that is exactly what one always ends up doing.

Regards,

Hans
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diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/usb/mmio-ohci.txt b/Documentation/devicetree/bindings/usb/mmio-ohci.txt
new file mode 100644
index 0000000..9c776ed
--- /dev/null
+++ b/Documentation/devicetree/bindings/usb/mmio-ohci.txt
@@ -0,0 +1,22 @@ 
+Generic MMIO OHCI controller
+
+Required properties:
+- compatible : "mmio-ohci"
+- reg : ohci controller register range (address and length)
+- interrupts : ohci controller interrupt
+
+Optional properties:
+- clocks : a list of phandle + clock specifier pairs
+- phys : phandle + phy specifier pair
+- phy-names : "usb"
+
+Example:
+
+	ohci0: ohci@0x01c14400 {
+		compatible = "mmio-ohci";
+		reg = <0x01c14400 0x100>;
+		interrupts = <64>;
+		clocks = <&usb_clk 6>, <&ahb_gates 2>;
+		phys = <&usbphy 1>;
+		phy-names = "usb";
+	};
diff --git a/drivers/usb/host/ohci-platform.c b/drivers/usb/host/ohci-platform.c
index f351ff5..31d9bdc 100644
--- a/drivers/usb/host/ohci-platform.c
+++ b/drivers/usb/host/ohci-platform.c
@@ -3,6 +3,7 @@ 
  *
  * Copyright 2007 Michael Buesch <m@bues.ch>
  * Copyright 2011-2012 Hauke Mehrtens <hauke@hauke-m.de>
+ * Copyright 2014 Hans de Goede <hdegoede@redhat.com>
  *
  * Derived from the OCHI-SSB driver
  * Derived from the OHCI-PCI driver
@@ -14,11 +15,14 @@ 
  * Licensed under the GNU/GPL. See COPYING for details.
  */
 
+#include <linux/clk.h>
+#include <linux/dma-mapping.h>
 #include <linux/hrtimer.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/err.h>
+#include <linux/phy/phy.h>
 #include <linux/platform_device.h>
 #include <linux/usb/ohci_pdriver.h>
 #include <linux/usb.h>
@@ -27,6 +31,13 @@ 
 #include "ohci.h"
 
 #define DRIVER_DESC "OHCI generic platform driver"
+#define OHCI_MAX_CLKS 3
+#define hcd_to_ohci_priv(h) ((struct ohci_platform_priv *)hcd_to_ohci(h)->priv)
+
+struct ohci_platform_priv {
+	struct clk *clks[OHCI_MAX_CLKS];
+	struct phy *phy;
+};
 
 static const char hcd_name[] = "ohci-platform";
 
@@ -48,11 +59,67 @@  static int ohci_platform_reset(struct usb_hcd *hcd)
 	return ohci_setup(hcd);
 }
 
+static int ohci_platform_power_on(struct platform_device *dev)
+{
+	struct usb_hcd *hcd = platform_get_drvdata(dev);
+	struct ohci_platform_priv *priv = hcd_to_ohci_priv(hcd);
+	int clk, ret;
+
+	for (clk = 0; priv->clks[clk] && clk < OHCI_MAX_CLKS; clk++) {
+		ret = clk_prepare_enable(priv->clks[clk]);
+		if (ret)
+			goto err_disable_clks;
+	}
+
+	if (priv->phy) {
+		ret = phy_init(priv->phy);
+		if (ret)
+			goto err_disable_clks;
+
+		ret = phy_power_on(priv->phy);
+		if (ret)
+			goto err_exit_phy;
+	}
+
+	return 0;
+
+err_exit_phy:
+	phy_exit(priv->phy);
+err_disable_clks:
+	while (--clk >= 0)
+		clk_disable_unprepare(priv->clks[clk]);
+
+	return ret;
+}
+
+static void ohci_platform_power_off(struct platform_device *dev)
+{
+	struct usb_hcd *hcd = platform_get_drvdata(dev);
+	struct ohci_platform_priv *priv = hcd_to_ohci_priv(hcd);
+	int clk;
+
+	if (priv->phy) {
+		phy_power_off(priv->phy);
+		phy_exit(priv->phy);
+	}
+
+	for (clk = OHCI_MAX_CLKS - 1; clk >= 0; clk--)
+		if (priv->clks[clk])
+			clk_disable_unprepare(priv->clks[clk]);
+}
+
 static struct hc_driver __read_mostly ohci_platform_hc_driver;
 
 static const struct ohci_driver_overrides platform_overrides __initconst = {
-	.product_desc =	"Generic Platform OHCI controller",
-	.reset =	ohci_platform_reset,
+	.product_desc =		"Generic Platform OHCI controller",
+	.reset =		ohci_platform_reset,
+	.extra_priv_size =	sizeof(struct ohci_platform_priv),
+};
+
+static struct usb_ohci_pdata ohci_platform_defaults = {
+	.power_on =		ohci_platform_power_on,
+	.power_suspend =	ohci_platform_power_off,
+	.power_off =		ohci_platform_power_off,
 };
 
 static int ohci_platform_probe(struct platform_device *dev)
@@ -60,17 +127,23 @@  static int ohci_platform_probe(struct platform_device *dev)
 	struct usb_hcd *hcd;
 	struct resource *res_mem;
 	struct usb_ohci_pdata *pdata = dev_get_platdata(&dev->dev);
-	int irq;
-	int err = -ENOMEM;
-
-	if (!pdata) {
-		WARN_ON(1);
-		return -ENODEV;
-	}
+	struct ohci_platform_priv *priv;
+	int clk, irq, err;
 
 	if (usb_disabled())
 		return -ENODEV;
 
+	/*
+	 * Use reasonable defaults so platforms don't have to provide these
+	 * with DT probing on ARM.
+	 */
+	if (!pdata)
+		pdata = &ohci_platform_defaults;
+
+	err = dma_coerce_mask_and_coherent(&dev->dev, DMA_BIT_MASK(32));
+	if (err)
+		return err;
+
 	irq = platform_get_irq(dev, 0);
 	if (irq < 0) {
 		dev_err(&dev->dev, "no irq provided");
@@ -83,17 +156,40 @@  static int ohci_platform_probe(struct platform_device *dev)
 		return -ENXIO;
 	}
 
+	hcd = usb_create_hcd(&ohci_platform_hc_driver, &dev->dev,
+			dev_name(&dev->dev));
+	if (!hcd)
+		return -ENOMEM;
+
+	platform_set_drvdata(dev, hcd);
+	dev->dev.platform_data = pdata;
+	priv = hcd_to_ohci_priv(hcd);
+
+	if (pdata == &ohci_platform_defaults && dev->dev.of_node) {
+		priv->phy = devm_phy_get(&dev->dev, "usb");
+		if (IS_ERR(priv->phy)) {
+			err = PTR_ERR(priv->phy);
+			if (err == -EPROBE_DEFER)
+				goto err_put_hcd;
+			priv->phy = NULL;
+		}
+
+		for (clk = 0; clk < OHCI_MAX_CLKS; clk++) {
+			priv->clks[clk] = of_clk_get(dev->dev.of_node, clk);
+			if (IS_ERR(priv->clks[clk])) {
+				err = PTR_ERR(priv->clks[clk]);
+				if (err == -EPROBE_DEFER)
+					goto err_put_clks;
+				priv->clks[clk] = NULL;
+				break;
+			}
+		}
+	}
+
 	if (pdata->power_on) {
 		err = pdata->power_on(dev);
 		if (err < 0)
-			return err;
-	}
-
-	hcd = usb_create_hcd(&ohci_platform_hc_driver, &dev->dev,
-			dev_name(&dev->dev));
-	if (!hcd) {
-		err = -ENOMEM;
-		goto err_power;
+			goto err_put_clks;
 	}
 
 	hcd->rsrc_start = res_mem->start;
@@ -102,21 +198,25 @@  static int ohci_platform_probe(struct platform_device *dev)
 	hcd->regs = devm_ioremap_resource(&dev->dev, res_mem);
 	if (IS_ERR(hcd->regs)) {
 		err = PTR_ERR(hcd->regs);
-		goto err_put_hcd;
+		goto err_power;
 	}
 	err = usb_add_hcd(hcd, irq, IRQF_SHARED);
 	if (err)
-		goto err_put_hcd;
-
-	platform_set_drvdata(dev, hcd);
+		goto err_power;
 
 	return err;
 
-err_put_hcd:
-	usb_put_hcd(hcd);
 err_power:
 	if (pdata->power_off)
 		pdata->power_off(dev);
+err_put_clks:
+	while (--clk >= 0)
+		clk_put(priv->clks[clk]);
+err_put_hcd:
+	if (pdata == &ohci_platform_defaults)
+		dev->dev.platform_data = NULL;
+
+	usb_put_hcd(hcd);
 
 	return err;
 }
@@ -125,13 +225,22 @@  static int ohci_platform_remove(struct platform_device *dev)
 {
 	struct usb_hcd *hcd = platform_get_drvdata(dev);
 	struct usb_ohci_pdata *pdata = dev_get_platdata(&dev->dev);
+	struct ohci_platform_priv *priv = hcd_to_ohci_priv(hcd);
+	int clk;
 
 	usb_remove_hcd(hcd);
-	usb_put_hcd(hcd);
 
 	if (pdata->power_off)
 		pdata->power_off(dev);
 
+	for (clk = 0; priv->clks[clk] && clk < OHCI_MAX_CLKS; clk++)
+		clk_put(priv->clks[clk]);
+
+	usb_put_hcd(hcd);
+
+	if (pdata == &ohci_platform_defaults)
+		dev->dev.platform_data = NULL;
+
 	return 0;
 }
 
@@ -178,6 +287,12 @@  static int ohci_platform_resume(struct device *dev)
 #define ohci_platform_resume	NULL
 #endif /* CONFIG_PM */
 
+static const struct of_device_id ohci_platform_ids[] = {
+	{ .compatible = "mmio-ohci", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ohci_platform_ids);
+
 static const struct platform_device_id ohci_platform_table[] = {
 	{ "ohci-platform", 0 },
 	{ }
@@ -198,6 +313,7 @@  static struct platform_driver ohci_platform_driver = {
 		.owner	= THIS_MODULE,
 		.name	= "ohci-platform",
 		.pm	= &ohci_platform_pm_ops,
+		.of_match_table = ohci_platform_ids,
 	}
 };