[PATCH 08/11] MXS: Add imx-otg driver

[marex@denx.de (Marek Vasut)]

Dear Sascha Hauer,

> On Sun, Apr 22, 2012 at 02:59:24PM +0200, Marek Vasut wrote:
> > This driver handles claiming of clocks and memory areas. These are later
> > properly delegated to it's child devices, the USB Host (ehci-mxs) and
> > USB Gadget (ci13xxx-mxs).
> > 
> > Signed-off-by: Marek Vasut <marex@denx.de>
> > Cc: Chen Peter-B29397 <B29397@freescale.com>
> > Cc: Detlev Zundel <dzu@denx.de>
> > Cc: Fabio Estevam <festevam@gmail.com>
> > Cc: Li Frank-B20596 <B20596@freescale.com>
> > Cc: Lin Tony-B19295 <B19295@freescale.com>
> > Cc: Linux USB <linux-usb@vger.kernel.org>
> > Cc: Sascha Hauer <s.hauer@pengutronix.de>
> > Cc: Shawn Guo <shawn.guo@freescale.com>
> > Cc: Shawn Guo <shawn.guo@linaro.org>
> > Cc: Stefano Babic <sbabic@denx.de>
> > Cc: Subodh Nijsure <snijsure@grid-net.com>
> > Cc: Tony Lin <tony.lin@freescale.com>
> > Cc: Wolfgang Denk <wd@denx.de>
> > ---
> > 
> >  drivers/usb/otg/Kconfig   |    6 +
> >  drivers/usb/otg/Makefile  |    1 +
> >  drivers/usb/otg/imx-otg.c |  282
> >  +++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 289
> >  insertions(+)
> >  create mode 100644 drivers/usb/otg/imx-otg.c
> > 
> > diff --git a/drivers/usb/otg/Kconfig b/drivers/usb/otg/Kconfig
> > index 5c87db0..e7c6325 100644
> > --- a/drivers/usb/otg/Kconfig
> > +++ b/drivers/usb/otg/Kconfig
> > @@ -116,6 +116,12 @@ config FSL_USB2_OTG
> > 
> >  	help
> >  	
> >  	  Enable this to support Freescale USB OTG transceiver.
> > 
> > +config USB_IMX_COMPOSITE
> > +	bool
> > +	help
> > +	  Composite driver that handles clock and memory mapping for
> > +	  i.MX USB host and USB PHY.
> > +
> > 
> >  config USB_MV_OTG
> >  
> >  	tristate "Marvell USB OTG support"
> >  	depends on USB_EHCI_MV && USB_MV_UDC && USB_SUSPEND
> > 
> > diff --git a/drivers/usb/otg/Makefile b/drivers/usb/otg/Makefile
> > index 41aa509..7d2c631 100644
> > --- a/drivers/usb/otg/Makefile
> > +++ b/drivers/usb/otg/Makefile
> > @@ -20,4 +20,5 @@ obj-$(CONFIG_USB_MSM_OTG)	+= msm_otg.o
> > 
> >  obj-$(CONFIG_AB8500_USB)	+= ab8500-usb.o
> >  fsl_usb2_otg-objs		:= fsl_otg.o otg_fsm.o
> >  obj-$(CONFIG_FSL_USB2_OTG)	+= fsl_usb2_otg.o
> > 
> > +obj-$(CONFIG_USB_IMX_COMPOSITE)	+= imx-otg.o
> > 
> >  obj-$(CONFIG_USB_MV_OTG)	+= mv_otg.o
> > 
> > diff --git a/drivers/usb/otg/imx-otg.c b/drivers/usb/otg/imx-otg.c
> > new file mode 100644
> > index 0000000..249b6b5
> > --- /dev/null
> > +++ b/drivers/usb/otg/imx-otg.c
> > @@ -0,0 +1,282 @@
> > +/*
> > + * drivers/usb/otg/imx-otg.c
> > + *
> > + * Freescale i.MX USB composite driver.
> > + *
> > + * Copyright (C) 2012 Marek Vasut <marex@denx.de>
> > + * on behalf of DENX Software Engineering GmbH
> > + *
> > + * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
> > + */
> > +
> > +#include <linux/module.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/dma-mapping.h>
> > +#include <linux/usb.h>
> > +#include <linux/usb/otg.h>
> > +#include <linux/usb/hcd.h>
> > +#include <linux/slab.h>
> > +#include <linux/delay.h>
> > +#include <linux/fsl/mxs-usb.h>
> > +#include <linux/io.h>
> > +
> > +#include <mach/common.h>
> > +#include <mach/hardware.h>
> > +#include <mach/devices-common.h>
> > +
> > +/*
> > + * Allocate platform device with the DMA mask, this is borrowed from
> > + * arch/arm/mach-mxs/devices.c
> > + */
> > +static struct platform_device *__devinit add_platform_device(
> > +		const char *name, int id,
> > +		const void *data, size_t size_data, u64 dmamask)
> > +{
> > +	int ret = -ENOMEM;
> > +	struct platform_device *pdev;
> > +
> > +	pdev = platform_device_alloc(name, id);
> > +	if (!pdev)
> > +		goto err;
> > +
> > +	if (dmamask) {
> > +		/*
> > +		 * This memory isn't freed when the device is put,
> > +		 * I don't have a nice idea for that though.  Conceptually
> > +		 * dma_mask in struct device should not be a pointer.
> > +		 * See http://thread.gmane.org/gmane.linux.kernel.pci/9081
> > +		 */
> > +		pdev->dev.dma_mask =
> > +			kmalloc(sizeof(*pdev->dev.dma_mask), GFP_KERNEL);
> > +		if (!pdev->dev.dma_mask)
> > +			/* ret is still -ENOMEM; */
> > +			goto err;
> > +
> > +		*pdev->dev.dma_mask = dmamask;
> > +		pdev->dev.coherent_dma_mask = dmamask;
> > +	}
> > +
> > +	if (data) {
> > +		ret = platform_device_add_data(pdev, data, size_data);
> > +		if (ret)
> > +			goto err;
> > +	}
> > +
> > +	ret = platform_device_add(pdev);
> > +	if (ret) {
> > +err:
> > +		if (dmamask)
> > +			kfree(pdev->dev.dma_mask);
> > +		platform_device_put(pdev);
> > +		return ERR_PTR(ret);
> > +	}
> > +
> > +	return pdev;
> > +}
> > +
> > +static int __devinit imx_usb_probe(struct platform_device *pdev)
> > +{
> > +	struct imx_usb_platform_data *pdata = pdev->dev.platform_data;
> > +	struct imx_usb *data;
> > +	struct usb_phy *phy;
> > +	int ret;
> > +	void *retp = NULL;
> > +
> > +	if (!pdata) {
> > +		dev_err(&pdev->dev, "No platform data supplied!\n");
> > +		return -ENODEV;
> > +	}
> > +
> > +	phy = usb_get_transceiver();
> > +	if (!phy)
> > +		return -EPROBE_DEFER;
> > +
> > +	/*
> > +	 * Until further notice, this claims all necessary resources.
> > +	 */
> > +
> > +	/* Allocate driver's private date. */
> > +	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
> > +	if (!data) {
> > +		ret = -ENOMEM;
> > +		goto err_alloc_data;
> > +	}
> > +
> > +	/* Claim the Host clock. */
> > +	data->clk = clk_get(&pdev->dev, "usb");
> > +	if (IS_ERR(data->clk)) {
> > +		dev_err(&pdev->dev, "Failed to claim clock for USB Host\n");
> > +		ret = PTR_ERR(data->clk);
> > +		goto err_claim_host_clock;
> > +	}
> > +
> > +	/* Prepare Host clock. */
> > +	ret = clk_prepare_enable(data->clk);
> > +	if (ret) {
> > +		dev_err(&pdev->dev, "Failed to enable clock for USB Host.\n");
> > +		goto err_prepare_host_clock;
> > +	}
> > +
> > +	/* Get memory area for EHCI host from resources. */
> > +	data->mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > +	if (!data->mem_res) {
> > +		dev_err(&pdev->dev, "Specify memory area for this USB Host!\n");
> > +		ret = -ENODEV;
> > +		goto err_get_host_resource;
> > +	}
> > +
> > +	/* Request the memory region for this USB Host. */
> > +	retp = devm_request_mem_region(&pdev->dev, data->mem_res->start,
> > +			resource_size(data->mem_res), pdev->name);
> > +	if (!retp) {
> > +		dev_err(&pdev->dev, "USB Host memory area already in use!\n");
> > +		ret = -EBUSY;
> > +		goto err_get_host_mem;
> > +	}
> > +
> > +	/* Map the memory region for USB Host. */
> > +	data->mem = devm_ioremap(&pdev->dev, data->mem_res->start,
> > +				resource_size(data->mem_res));
> > +	if (!data->mem) {
> > +		dev_err(&pdev->dev, "Memory mapping of USB Host failed!\n");
> > +		ret = -EFAULT;
> > +		goto err_map_host_mem;
> > +	}
> > +
> > +	/* Get IRQ for EHCI host from resources. */
> > +	data->irq = platform_get_irq(pdev, 0);
> > +	if (data->irq < 0) {
> > +		dev_err(&pdev->dev, "Specify IRQ for this USB Host!\n");
> > +		ret = -ENODEV;
> > +		goto err_get_host_irq;
> > +	}
> > +
> > +	/*
> > +	 * Now finally probe the Host driver!
> > +	 */
> > +	if (pdata->host_mode) {
> > +		data->pdev_host = add_platform_device("mxs-ehci", -1,
> > +							data, sizeof(*data),
> > +							DMA_BIT_MASK(32));
> > +		if (!data->pdev_host) {
> > +			dev_err(&pdev->dev, "Failed registering Host!\n");
> > +			ret = -ENODEV;
> > +			goto err_register_host;
> > +		}
> > +	} else {
> > +		data->pdev_gadget = add_platform_device("ci13xxx-mxs", -1,
> > +							data, sizeof(*data),
> > +							DMA_BIT_MASK(32));
> > +		if (!data->pdev_gadget) {
> > +			dev_err(&pdev->dev, "Failed registering Host!\n");
> > +			ret = -ENODEV;
> > +			goto err_register_gadget;
> > +		}
> > +	}
> > +
> > +	/*
> > +	 * Initialize the transceiver
> > +	 */
> > +	phy = usb_get_transceiver();
> > +	if (!phy) {
> > +		dev_err(&pdev->dev, "Unable to find transceiver.\n");
> > +		ret = -ENODEV;
> > +		goto err_phy;
> > +	}
> > +
> > +	ret = usb_phy_init(phy);
> > +	if (ret < 0) {
> > +		dev_err(&pdev->dev, "Unable init transceiver\n");
> > +		ret = -ENODEV;
> > +		goto err_phy_init;
> > +	}
> > +
> > +	/* Set up the PORTSCx register */
> > +	writel(0, data->mem + 0x144);
> > +
> > +	return 0;
> > +
> > +err_phy_init:
> > +	if (phy)
> > +		usb_put_transceiver(phy);
> > +err_phy:
> > +	if (data->pdev_gadget)
> > +		platform_device_unregister(data->pdev_gadget);
> > +err_register_gadget:
> > +	if (data->pdev_host)
> > +		platform_device_unregister(data->pdev_host);
> > +err_register_host:
> > +err_get_host_irq:
> > +	iounmap(data->mem);
> > +err_map_host_mem:
> > +	release_mem_region(data->mem_res->start,
> > +			resource_size(data->mem_res));
> > +err_get_host_mem:
> > +	data->mem_res = NULL;
> > +err_get_host_resource:
> > +	clk_disable_unprepare(data->clk);
> > +err_prepare_host_clock:
> > +	clk_put(data->clk);
> > +err_claim_host_clock:
> > +err_alloc_data:
> > +	return ret;
> > +}
> > +
> > +static int __devexit imx_usb_remove(struct platform_device *pdev)
> > +{
> > +	struct imx_usb *data = platform_get_drvdata(pdev);
> > +
> > +	if (data->pdev_gadget)
> > +		platform_device_unregister(data->pdev_gadget);
> > +
> > +	if (data->pdev_host)
> > +		platform_device_unregister(data->pdev_host);
> > +
> > +	iounmap(data->mem);
> > +	release_mem_region(data->mem_res->start,
> > +			resource_size(data->mem_res));
> 
> Again, you are using the managed versions of ioremap and
> request_mem_region. The whole point of these functions is that these
> resources are automatically released on driver exit (or failure at
> probe).

Argh. Anyway, I'm more interested to hear your opinion on the general concept, 
esp. on Peter's comment on otg_set_host()/otg_set_peripheral() -- their 
implementation should be in the PHY driver and they should be called from EHCI 
host / ci13xxx gadget driver, correct?

> Sascha