[PATCH 09/13] mfd: omap-usb-host: Add device tree support and binding information
kishon
kishon at ti.com
Tue Feb 5 07:11:02 EST 2013
Hi,
On Tuesday 05 February 2013 04:28 PM, Roger Quadros wrote:
> 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 <sameo at linux.intel.com>
>>> Signed-off-by: Roger Quadros <rogerq at ti.com>
>>> ---
>>> .../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 <keshava_mgowda at ti.com>
>>> + * Author: Roger Quadros <rogerq at ti.com>
>>> *
>>> * 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.
No. I've done it for dwc3 in usb/dwc3/dwc3-omap.c. (you can check usb-next)
>
> It kind of makes sense for EHCI/OHCI, cause the devices are always present
> on the SoC.
Not true for devices created in drivers/ IMHO. It makes sense only if
you create the device in some platform specific initialization file.
> Also, this driver can't be built as a module so it can never be removed.
Why is this restriction btw?
Thanks
Kishon
More information about the linux-arm-kernel
mailing list