Subject: [PATCH 09/13] mfd: omap-usb-host: Add device tree support and binding information

From: [email-masked] (Roger Quadros)
Date: Tue, 5 Feb 2013 12:58:12 +0200

On 02/05/2013 08:16 AM, kishon wrote:
> On Monday 04 February 2013 09:28 PM, Roger Quadros wrote:
>> Allows the OMAP HS USB host controller to be specified
>> via device tree.
>>
>> CC: Samuel Ortiz <[email-masked]>
>> Signed-off-by: Roger Quadros <[email-masked]>
>> ---
>>   .../devicetree/bindings/mfd/omap-usb-host.txt      |   68 ++++++++++++++++
>>   drivers/mfd/omap-usb-host.c                        |   83 ++++++++++++++++++--
>>   2 files changed, 145 insertions(+), 6 deletions(-)
>>   create mode 100644 Documentation/devicetree/bindings/mfd/omap-usb-host.txt
>>
>> diff --git a/Documentation/devicetree/bindings/mfd/omap-usb-host.txt b/Documentation/devicetree/bindings/mfd/omap-usb-host.txt
>> new file mode 100644
>> index 0000000..2196893
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/mfd/omap-usb-host.txt
>> @@ -0,0 +1,68 @@
>> +OMAP HS USB Host
>> +
>> +Required properties:
>> +
>> +- compatible: should be "ti,usbhs-host"
>> +- reg: should contain one register range i.e. start and length
>> +- ti,hwmods: must contain "usb_host_hs"
>> +
>> +Optional properties:
>> +
>> +- nports: number of USB ports. Usually this is automatically detected
>> +  from the IP's revision register but can be overridden by specifying
>> +  this property.
>> +
>> +- portN_mode: Integer specifying the port mode for port N, where N can be
>> +  from 1 to nports. The port mode must be as per enum usbhs_omap_port_mode
>> +  in include/linux/platform_data/usb-omap.h
>> +  If the port mode is not specified, that port is treated as unused.
>> +
>> +- single_ulpi_bypass: Must be present if the controller contains a single
>> +  ULPI bypass control bit. e.g. OMAP3 silicon <= ES2.1
>> +
>> +Required properties if child node exists:
>> +
>> +- #address-cells: Must be 1
>> +- #size-cells: Must be 1
>> +- ranges: must be present
>> +
>> +Properties for children:
>> +
>> +The OMAP HS USB Host subsystem contains EHCI and OHCI controllers.
>> +See Documentation/devicetree/bindings/usb/omap-ehci.txt and
>> +omap3-ohci.txt
>> +
>> +Example for OMAP4:
>> +
>> +usbhshost: usbhshost at 0x4a064000 {
>> +    compatible = "ti,usbhs-host";
>> +    reg = <0x4a064000 0x800>;
>> +    ti,hwmods = "usb_host_hs";
>> +    #address-cells = <1>;
>> +    #size-cells = <1>;
>> +    ranges;
>> +
>> +    usbhsohci: ohci at 0x4a064800 {
>> +        compatible = "ti,omap3-ohci", "usb-ohci";
>> +        reg = <0x4a064800 0x400>;
>> +        interrupt-parent = <&gic>;
>> +        interrupts = <0 76 0x4>;
>> +    };
>> +
>> +    usbhsehci: ehci at 0x4a064c00 {
>> +        compatible = "ti,omap-ehci", "usb-ehci";
>> +        reg = <0x4a064c00 0x400>;
>> +        interrupt-parent = <&gic>;
>> +        interrupts = <0 77 0x4>;
>> +    };
>> +};
>> +
>> +&usbhshost {
>> +    port1_mode = <1>; /* OMAP_EHCI_PORT_MODE_PHY */
>> +    port2_mode = <2>; /* OMAP_EHCI_PORT_MODE_TLL */
>> +    port3_mode = <1>; /* OMAP_EHCI_PORT_MODE_PHY */
>> +};
>> +
>> +&usbhsehci {
>> +    phy = <&hsusb1_phy 0 &hsusb3_phy>;
>> +};
>> diff --git a/drivers/mfd/omap-usb-host.c b/drivers/mfd/omap-usb-host.c
>> index f8ed08e..0f67856 100644
>> --- a/drivers/mfd/omap-usb-host.c
>> +++ b/drivers/mfd/omap-usb-host.c
>> @@ -1,8 +1,9 @@
>>   /**
>>    * omap-usb-host.c - The USBHS core driver for OMAP EHCI & OHCI
>>    *
>> - * Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com
>> + * Copyright (C) 2011-2013 Texas Instruments Incorporated - http://www.ti.com
>>    * Author: Keshava Munegowda <[email-masked]>
>> + * Author: Roger Quadros <[email-masked]>
>>    *
>>    * This program is free software: you can redistribute it and/or modify
>>    * it under the terms of the GNU General Public License version 2  of
>> @@ -27,6 +28,8 @@
>>   #include <linux/platform_device.h>
>>   #include <linux/platform_data/usb-omap.h>
>>   #include <linux/pm_runtime.h>
>> +#include <linux/of.h>
>> +#include <linux/of_platform.h>
>>
>>   #include "omap-usb.h"
>>
>> @@ -464,6 +467,37 @@ static void omap_usbhs_init(struct device *dev)
>>       pm_runtime_put_sync(dev);
>>   }
>>
>> +static int usbhs_omap_get_dt_pdata(struct device_node *node,
>> +                    struct usbhs_omap_platform_data *pdata)
>> +{
>> +    int ret, i;
>> +
>> +    ret = of_property_read_u32(node, "nports", &pdata->nports);
>> +    if (ret)
>> +        pdata->nports = 0;
>> +
>> +    /* get port modes */
>> +    for (i = 0; i < OMAP3_HS_USB_PORTS; i++) {
>> +        char prop[11];
>> +
>> +        snprintf(prop, sizeof(prop), "port%d_mode", i + 1);
>> +        ret = of_property_read_u32(node, prop, &pdata->port_mode[i]);
>> +        if (ret)
>> +            pdata->port_mode[i] = OMAP_USBHS_PORT_MODE_UNUSED;
>> +    }
>> +
>> +    /* get flags */
>> +    pdata->single_ulpi_bypass = of_property_read_bool(node,
>> +                        "single_ulpi_bypass");
>> +    return 0;
>> +}
>> +
>> +static struct of_device_id usbhs_child_match_table[] __initdata = {
>> +    { .compatible = "ti,omap-ehci", },
>> +    { .compatible = "ti,omap-ohci", },
>> +    { }
>> +};
>> +
>>   /**
>>    * usbhs_omap_probe - initialize TI-based HCDs
>>    *
>> @@ -479,6 +513,21 @@ static int usbhs_omap_probe(struct platform_device *pdev)
>>       int                i;
>>       bool                need_logic_fck;
>>
>> +    if (dev->of_node) {
>> +        /* For DT boot we populate platform data from OF node */
>> +        pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
>> +        if (!pdata)
>> +            return -ENOMEM;
>> +
>> +        if (usbhs_omap_get_dt_pdata(dev->of_node, pdata)) {
>> +            dev_err(dev,
>> +                "Error getting platform data from DT node\n");
>> +            return -ENODEV;
>> +        }
>> +
>> +        dev->platform_data = pdata;
>> +    }
>> +
>>       if (!pdata) {
>>           dev_err(dev, "Missing platform data\n");
>>           return -ENODEV;
>> @@ -490,7 +539,7 @@ static int usbhs_omap_probe(struct platform_device *pdev)
>>           return -ENOMEM;
>>       }
>>
>> -    res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "uhh");
>> +    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>       omap->uhh_base = devm_request_and_ioremap(dev, res);
>>       if (!omap->uhh_base) {
>>           dev_err(dev, "Resource request/ioremap failed\n");
>> @@ -661,10 +710,23 @@ static int usbhs_omap_probe(struct platform_device *pdev)
>>       }
>>
>>       omap_usbhs_init(dev);
>> -    ret = omap_usbhs_alloc_children(pdev);
>> -    if (ret) {
>> -        dev_err(dev, "omap_usbhs_alloc_children failed\n");
>> -        goto err_alloc;
>> +
>> +    if (dev->of_node) {
>> +        ret = of_platform_populate(dev->of_node,
>> +                usbhs_child_match_table, NULL, dev);
>> +
>> +        if (ret) {
>> +            dev_err(dev, "Failed to create DT children: %d\n", ret);
>> +            goto err_alloc;
>> +        }
>> +
>> +    } else {
>> +        ret = omap_usbhs_alloc_children(pdev);
>> +        if (ret) {
>> +            dev_err(dev, "omap_usbhs_alloc_children failed: %d\n",
>> +                        ret);
>> +            goto err_alloc;
>> +        }
> These child devices should be destroyed on driver remove..no?
> 
I could not find a function that does the opposite of of_platform_populate() or
of_platform_device_create_pdata(). It seems that platform devices created via
device tree are never meant to be destroyed.

It kind of makes sense for EHCI/OHCI, cause the devices are always present
on the SoC. Also, this driver can't be built as a module so it can never be removed.

So let's leave this patch the way it is except removing 0x from the device name
in the example.

cheers,
-roger