[PATCH v3 0/2] Add USB support for Ingenic JZ4740

[PATCH v3 0/2] Add USB support for Ingenic JZ4740

[Apelete Seketeli]

Hello,

Following the fix I submitted a few weeks ago, here is a set of
patches that adds USB support for the Ingenic JZ4740 MIPS SoC.

The JZ4740 is found in the Ben NanoNote handheld computer which is
built by the Qi-Hardware community.
Even though Ben NanoNote is already supported in the kernel, we were
relying on an out-of-tree gadget driver to make use of the JZ4740 USB
Device Controller.

The patches that come as a follow-up of this message are an attempt to
provide USB support through an musb glue layer.

Changes since v2:
	- usb: musb-jz4740: Add COMPILE_TEST dependency in Kconfig
	- usb: musb-jz4740: Split drivers/ files from arch/ files

Changes since v1:
	- usb: musb-jz4740: Don't manually free device managed resources
	- usb: musb-jz4740: Move musb_hdrc_config to the glue driver
	- usb: musb-jz4740: Move jz4740 specific fifo config to the jz4740 glue
	- usb: musb-jz4740: Mask host mode only IRQ bits
	- usb: musb-jz4740: Remove set_vbus callback
	- usb: musb_gadget: Use is_otg flag to set gadget peripheral mode on reset

Changes were rebased on top of Felipe Balbi's USB Subsystem master
branch, built and tested on device successfully.

The following changes since commit 7c0883d:

  Merge branch 'next'

are available in the git repository at:

  git://seketeli.fr/~apelete/linux-usb.git musb-jz4740

Apelete Seketeli (2):
  usb: musb: add support for JZ4740 usb device  controller
  usb: musb: fix setting JZ4740 gadget periphal mode on reset

 drivers/usb/musb/Kconfig       |    8 +-
 drivers/usb/musb/Makefile      |    1 +
 drivers/usb/musb/jz4740.c      |  201 ++++++++++++++++++++++++++++++++++++++++
 drivers/usb/musb/musb_gadget.c |   10 +-
 4 files changed, 218 insertions(+), 2 deletions(-)
 create mode 100644 drivers/usb/musb/jz4740.c

-- 
1.7.10.4

[PATCH v3 1/2] usb: musb: add support for JZ4740 usb device controller

[Apelete Seketeli]

Add support for Ingenic JZ4740 USB Device Controller through a
specific musb glue layer.

JZ4740 UDC not being OTG compatible and missing some hardware
registers, this musb glue layer is written from scratch to be used in
gadget mode only and take silicon design specifics into account.

Signed-off-by: Apelete Seketeli <apelete@seketeli.net>
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
---
 drivers/usb/musb/Kconfig  |    8 +-
 drivers/usb/musb/Makefile |    1 +
 drivers/usb/musb/jz4740.c |  201 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 209 insertions(+), 1 deletion(-)
 create mode 100644 drivers/usb/musb/jz4740.c

diff --git a/drivers/usb/musb/Kconfig b/drivers/usb/musb/Kconfig
index 57dfc0c..14d7e72 100644
--- a/drivers/usb/musb/Kconfig
+++ b/drivers/usb/musb/Kconfig
@@ -93,6 +93,12 @@ config USB_MUSB_BLACKFIN
 config USB_MUSB_UX500
 	tristate "Ux500 platforms"
 
+config USB_MUSB_JZ4740
+	tristate "JZ4740"
+	depends on MACH_JZ4740 || COMPILE_TEST
+	depends on USB_MUSB_GADGET
+	depends on USB_OTG_BLACKLIST_HUB
+
 endchoice
 
 config USB_MUSB_AM335X_CHILD
@@ -100,7 +106,7 @@ config USB_MUSB_AM335X_CHILD
 
 choice
 	prompt 'MUSB DMA mode'
-	default MUSB_PIO_ONLY if ARCH_MULTIPLATFORM
+	default MUSB_PIO_ONLY if ARCH_MULTIPLATFORM || USB_MUSB_JZ4740
 	default USB_UX500_DMA if USB_MUSB_UX500
 	default USB_INVENTRA_DMA if USB_MUSB_OMAP2PLUS || USB_MUSB_BLACKFIN
 	default USB_TI_CPPI_DMA if USB_MUSB_DAVINCI
diff --git a/drivers/usb/musb/Makefile b/drivers/usb/musb/Makefile
index c5ea5c6..ba49501 100644
--- a/drivers/usb/musb/Makefile
+++ b/drivers/usb/musb/Makefile
@@ -19,6 +19,7 @@ obj-$(CONFIG_USB_MUSB_DAVINCI)			+= davinci.o
 obj-$(CONFIG_USB_MUSB_DA8XX)			+= da8xx.o
 obj-$(CONFIG_USB_MUSB_BLACKFIN)			+= blackfin.o
 obj-$(CONFIG_USB_MUSB_UX500)			+= ux500.o
+obj-$(CONFIG_USB_MUSB_JZ4740)			+= jz4740.o
 
 
 obj-$(CONFIG_USB_MUSB_AM335X_CHILD)		+= musb_am335x.o
diff --git a/drivers/usb/musb/jz4740.c b/drivers/usb/musb/jz4740.c
new file mode 100644
index 0000000..5f30537
--- /dev/null
+++ b/drivers/usb/musb/jz4740.c
@@ -0,0 +1,201 @@
+/*
+ * Ingenic JZ4740 "glue layer"
+ *
+ * Copyright (C) 2013, Apelete Seketeli <apelete@seketeli.net>
+ *
+ * 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.
+ *
+ * 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/clk.h>
+#include <linux/dma-mapping.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#include "musb_core.h"
+
+struct jz4740_glue {
+	struct device           *dev;
+	struct platform_device  *musb;
+	struct clk		*clk;
+};
+
+static irqreturn_t jz4740_musb_interrupt(int irq, void *__hci)
+{
+	unsigned long   flags;
+	irqreturn_t     retval = IRQ_NONE;
+	struct musb     *musb = __hci;
+
+	spin_lock_irqsave(&musb->lock, flags);
+
+	musb->int_usb = musb_readb(musb->mregs, MUSB_INTRUSB);
+	musb->int_tx = musb_readw(musb->mregs, MUSB_INTRTX);
+	musb->int_rx = musb_readw(musb->mregs, MUSB_INTRRX);
+
+	/*
+	 * The controller is gadget only, the state of the host mode IRQ bits is
+	 * undefined. Mask them to make sure that the musb driver core will
+	 * never see them set
+	 */
+	musb->int_usb &= MUSB_INTR_SUSPEND | MUSB_INTR_RESUME |
+	    MUSB_INTR_RESET | MUSB_INTR_SOF;
+
+	if (musb->int_usb || musb->int_tx || musb->int_rx)
+		retval = musb_interrupt(musb);
+
+	spin_unlock_irqrestore(&musb->lock, flags);
+
+	return retval;
+}
+
+static struct musb_fifo_cfg jz4740_musb_fifo_cfg[] = {
+{ .hw_ep_num = 1, .style = FIFO_TX, .maxpacket = 512, },
+{ .hw_ep_num = 1, .style = FIFO_RX, .maxpacket = 512, },
+{ .hw_ep_num = 2, .style = FIFO_TX, .maxpacket = 64, },
+};
+
+static struct musb_hdrc_config jz4740_musb_config = {
+	/* Silicon does not implement USB OTG. */
+	.multipoint = 0,
+	/* Max EPs scanned, driver will decide which EP can be used. */
+	.num_eps    = 4,
+	/* RAMbits needed to configure EPs from table */
+	.ram_bits   = 9,
+	.fifo_cfg = jz4740_musb_fifo_cfg,
+	.fifo_cfg_size = ARRAY_SIZE(jz4740_musb_fifo_cfg),
+};
+
+static struct musb_hdrc_platform_data jz4740_musb_platform_data = {
+	.mode   = MUSB_PERIPHERAL,
+	.config = &jz4740_musb_config,
+};
+
+static int jz4740_musb_init(struct musb *musb)
+{
+	musb->xceiv = usb_get_phy(USB_PHY_TYPE_USB2);
+	if (!musb->xceiv) {
+		pr_err("HS UDC: no transceiver configured\n");
+		return -ENODEV;
+	}
+
+	/* Silicon does not implement ConfigData register.
+	 * Set dyn_fifo to avoid reading EP config from hardware.
+	 */
+	musb->dyn_fifo = true;
+
+	musb->isr = jz4740_musb_interrupt;
+
+	return 0;
+}
+
+static int jz4740_musb_exit(struct musb *musb)
+{
+	usb_put_phy(musb->xceiv);
+
+	return 0;
+}
+
+static const struct musb_platform_ops jz4740_musb_ops = {
+	.init		= jz4740_musb_init,
+	.exit		= jz4740_musb_exit,
+};
+
+static int jz4740_probe(struct platform_device *pdev)
+{
+	struct musb_hdrc_platform_data	*pdata = &jz4740_musb_platform_data;
+	struct platform_device		*musb;
+	struct jz4740_glue		*glue;
+	struct clk                      *clk;
+	int				ret;
+
+	glue = devm_kzalloc(&pdev->dev, sizeof(*glue), GFP_KERNEL);
+	if (!glue)
+		return -ENOMEM;
+
+	musb = platform_device_alloc("musb-hdrc", PLATFORM_DEVID_AUTO);
+	if (!musb) {
+		dev_err(&pdev->dev, "failed to allocate musb device\n");
+		return -ENOMEM;
+	}
+
+	clk = devm_clk_get(&pdev->dev, "udc");
+	if (IS_ERR(clk)) {
+		dev_err(&pdev->dev, "failed to get clock\n");
+		ret = PTR_ERR(clk);
+		goto err_platform_device_put;
+	}
+
+	ret = clk_prepare_enable(clk);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to enable clock\n");
+		goto err_platform_device_put;
+	}
+
+	musb->dev.parent		= &pdev->dev;
+
+	glue->dev			= &pdev->dev;
+	glue->musb			= musb;
+	glue->clk			= clk;
+
+	pdata->platform_ops		= &jz4740_musb_ops;
+
+	platform_set_drvdata(pdev, glue);
+
+	ret = platform_device_add_resources(musb, pdev->resource,
+					    pdev->num_resources);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to add resources\n");
+		goto err_clk_disable;
+	}
+
+	ret = platform_device_add_data(musb, pdata, sizeof(*pdata));
+	if (ret) {
+		dev_err(&pdev->dev, "failed to add platform_data\n");
+		goto err_clk_disable;
+	}
+
+	ret = platform_device_add(musb);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register musb device\n");
+		goto err_clk_disable;
+	}
+
+	return 0;
+
+err_clk_disable:
+	clk_disable_unprepare(clk);
+err_platform_device_put:
+	platform_device_put(musb);
+	return ret;
+}
+
+static int jz4740_remove(struct platform_device *pdev)
+{
+	struct jz4740_glue	*glue = platform_get_drvdata(pdev);
+
+	platform_device_unregister(glue->musb);
+	clk_disable_unprepare(glue->clk);
+
+	return 0;
+}
+
+static struct platform_driver jz4740_driver = {
+	.probe		= jz4740_probe,
+	.remove		= jz4740_remove,
+	.driver		= {
+		.name	= "musb-jz4740",
+	},
+};
+
+MODULE_DESCRIPTION("JZ4740 MUSB Glue Layer");
+MODULE_AUTHOR("Apelete Seketeli <apelete@seketeli.net>");
+MODULE_LICENSE("GPL v2");
+module_platform_driver(jz4740_driver);
-- 
1.7.10.4

[PATCH v3 2/2] usb: musb: fix setting JZ4740 gadget periphal mode on reset

[Apelete Seketeli]

JZ4740 USB Device Controller is not OTG compatible and does not have
DEVCTL register in silicon.

During ethernet-over-usb transactions, on reset, musb driver tries to
read from DEVCTL and consequently sets device as host (A-Device)
instead of peripheral (B-Device), which makes it a composite device to
the USB gadget driver.
This induces a kernel panic during power down where the USB gadget
driver does a null pointer dereference when trying to access the
composite device configuration.

On reset, do not rely on DEVCTL value for setting gadget peripheral
mode. Use is_otg flag instead to set it to B-Device.

Signed-off-by: Apelete Seketeli <apelete@seketeli.net>
---
 drivers/usb/musb/musb_gadget.c |   10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c
index c410a7f..d4aa779 100644
--- a/drivers/usb/musb/musb_gadget.c
+++ b/drivers/usb/musb/musb_gadget.c
@@ -2119,7 +2119,15 @@ __acquires(musb->lock)
 	/* Normal reset, as B-Device;
 	 * or else after HNP, as A-Device
 	 */
-	if (devctl & MUSB_DEVCTL_BDEVICE) {
+	if (!musb->g.is_otg) {
+		/* USB device controllers that are not OTG compatible
+		 * may not have DEVCTL register in silicon.
+		 * In that case, do not rely on devctl for setting
+		 * peripheral mode.
+		 */
+		musb->xceiv->state = OTG_STATE_B_PERIPHERAL;
+		musb->g.is_a_peripheral = 0;
+	} else if (devctl & MUSB_DEVCTL_BDEVICE) {
 		musb->xceiv->state = OTG_STATE_B_PERIPHERAL;
 		musb->g.is_a_peripheral = 0;
 	} else {
-- 
1.7.10.4

Re: [PATCH v3 1/2] usb: musb: add support for JZ4740 usb device controller

[Richard Weinberger]

On Thu, Dec 19, 2013 at 9:42 PM, Apelete Seketeli <apelete@seketeli.net> wrote:
> Add support for Ingenic JZ4740 USB Device Controller through a
> specific musb glue layer.
>
> JZ4740 UDC not being OTG compatible and missing some hardware
> registers, this musb glue layer is written from scratch to be used in
> gadget mode only and take silicon design specifics into account.
>
> Signed-off-by: Apelete Seketeli <apelete@seketeli.net>
> Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
> ---
>  drivers/usb/musb/Kconfig  |    8 +-
>  drivers/usb/musb/Makefile |    1 +
>  drivers/usb/musb/jz4740.c |  201 +++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 209 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/usb/musb/jz4740.c
>
> diff --git a/drivers/usb/musb/Kconfig b/drivers/usb/musb/Kconfig
> index 57dfc0c..14d7e72 100644
> --- a/drivers/usb/musb/Kconfig
> +++ b/drivers/usb/musb/Kconfig
> @@ -93,6 +93,12 @@ config USB_MUSB_BLACKFIN
>  config USB_MUSB_UX500
>         tristate "Ux500 platforms"
>
> +config USB_MUSB_JZ4740
> +       tristate "JZ4740"
> +       depends on MACH_JZ4740 || COMPILE_TEST
> +       depends on USB_MUSB_GADGET
> +       depends on USB_OTG_BLACKLIST_HUB
> +
>  endchoice
>
>  config USB_MUSB_AM335X_CHILD
> @@ -100,7 +106,7 @@ config USB_MUSB_AM335X_CHILD
>
>  choice
>         prompt 'MUSB DMA mode'
> -       default MUSB_PIO_ONLY if ARCH_MULTIPLATFORM
> +       default MUSB_PIO_ONLY if ARCH_MULTIPLATFORM || USB_MUSB_JZ4740

Just out of curiosity, why can't we use DMA?

>         default USB_UX500_DMA if USB_MUSB_UX500
>         default USB_INVENTRA_DMA if USB_MUSB_OMAP2PLUS || USB_MUSB_BLACKFIN
>         default USB_TI_CPPI_DMA if USB_MUSB_DAVINCI
> diff --git a/drivers/usb/musb/Makefile b/drivers/usb/musb/Makefile
> index c5ea5c6..ba49501 100644
> --- a/drivers/usb/musb/Makefile
> +++ b/drivers/usb/musb/Makefile
> @@ -19,6 +19,7 @@ obj-$(CONFIG_USB_MUSB_DAVINCI)                        += davinci.o
>  obj-$(CONFIG_USB_MUSB_DA8XX)                   += da8xx.o
>  obj-$(CONFIG_USB_MUSB_BLACKFIN)                        += blackfin.o
>  obj-$(CONFIG_USB_MUSB_UX500)                   += ux500.o
> +obj-$(CONFIG_USB_MUSB_JZ4740)                  += jz4740.o
>
>
>  obj-$(CONFIG_USB_MUSB_AM335X_CHILD)            += musb_am335x.o
> diff --git a/drivers/usb/musb/jz4740.c b/drivers/usb/musb/jz4740.c
> new file mode 100644
> index 0000000..5f30537
> --- /dev/null
> +++ b/drivers/usb/musb/jz4740.c
> @@ -0,0 +1,201 @@
> +/*
> + * Ingenic JZ4740 "glue layer"
> + *
> + * Copyright (C) 2013, Apelete Seketeli <apelete@seketeli.net>
> + *
> + * 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.
> + *
> + * 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/clk.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/errno.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +
> +#include "musb_core.h"
> +
> +struct jz4740_glue {
> +       struct device           *dev;
> +       struct platform_device  *musb;
> +       struct clk              *clk;
> +};
> +
> +static irqreturn_t jz4740_musb_interrupt(int irq, void *__hci)
> +{
> +       unsigned long   flags;
> +       irqreturn_t     retval = IRQ_NONE;
> +       struct musb     *musb = __hci;
> +
> +       spin_lock_irqsave(&musb->lock, flags);
> +
> +       musb->int_usb = musb_readb(musb->mregs, MUSB_INTRUSB);
> +       musb->int_tx = musb_readw(musb->mregs, MUSB_INTRTX);
> +       musb->int_rx = musb_readw(musb->mregs, MUSB_INTRRX);
> +
> +       /*
> +        * The controller is gadget only, the state of the host mode IRQ bits is
> +        * undefined. Mask them to make sure that the musb driver core will
> +        * never see them set
> +        */
> +       musb->int_usb &= MUSB_INTR_SUSPEND | MUSB_INTR_RESUME |
> +           MUSB_INTR_RESET | MUSB_INTR_SOF;
> +
> +       if (musb->int_usb || musb->int_tx || musb->int_rx)
> +               retval = musb_interrupt(musb);
> +
> +       spin_unlock_irqrestore(&musb->lock, flags);
> +
> +       return retval;
> +}
> +
> +static struct musb_fifo_cfg jz4740_musb_fifo_cfg[] = {
> +{ .hw_ep_num = 1, .style = FIFO_TX, .maxpacket = 512, },
> +{ .hw_ep_num = 1, .style = FIFO_RX, .maxpacket = 512, },
> +{ .hw_ep_num = 2, .style = FIFO_TX, .maxpacket = 64, },
> +};
> +
> +static struct musb_hdrc_config jz4740_musb_config = {
> +       /* Silicon does not implement USB OTG. */
> +       .multipoint = 0,
> +       /* Max EPs scanned, driver will decide which EP can be used. */
> +       .num_eps    = 4,
> +       /* RAMbits needed to configure EPs from table */
> +       .ram_bits   = 9,
> +       .fifo_cfg = jz4740_musb_fifo_cfg,
> +       .fifo_cfg_size = ARRAY_SIZE(jz4740_musb_fifo_cfg),
> +};
> +
> +static struct musb_hdrc_platform_data jz4740_musb_platform_data = {
> +       .mode   = MUSB_PERIPHERAL,
> +       .config = &jz4740_musb_config,
> +};
> +
> +static int jz4740_musb_init(struct musb *musb)
> +{
> +       musb->xceiv = usb_get_phy(USB_PHY_TYPE_USB2);
> +       if (!musb->xceiv) {
> +               pr_err("HS UDC: no transceiver configured\n");
> +               return -ENODEV;
> +       }
> +
> +       /* Silicon does not implement ConfigData register.
> +        * Set dyn_fifo to avoid reading EP config from hardware.
> +        */
> +       musb->dyn_fifo = true;
> +
> +       musb->isr = jz4740_musb_interrupt;
> +
> +       return 0;
> +}
> +
> +static int jz4740_musb_exit(struct musb *musb)
> +{
> +       usb_put_phy(musb->xceiv);
> +
> +       return 0;
> +}
> +
> +static const struct musb_platform_ops jz4740_musb_ops = {
> +       .init           = jz4740_musb_init,
> +       .exit           = jz4740_musb_exit,
> +};
> +
> +static int jz4740_probe(struct platform_device *pdev)
> +{
> +       struct musb_hdrc_platform_data  *pdata = &jz4740_musb_platform_data;
> +       struct platform_device          *musb;
> +       struct jz4740_glue              *glue;
> +       struct clk                      *clk;
> +       int                             ret;
> +
> +       glue = devm_kzalloc(&pdev->dev, sizeof(*glue), GFP_KERNEL);
> +       if (!glue)
> +               return -ENOMEM;
> +
> +       musb = platform_device_alloc("musb-hdrc", PLATFORM_DEVID_AUTO);
> +       if (!musb) {
> +               dev_err(&pdev->dev, "failed to allocate musb device\n");
> +               return -ENOMEM;
> +       }
> +
> +       clk = devm_clk_get(&pdev->dev, "udc");
> +       if (IS_ERR(clk)) {
> +               dev_err(&pdev->dev, "failed to get clock\n");
> +               ret = PTR_ERR(clk);
> +               goto err_platform_device_put;
> +       }
> +
> +       ret = clk_prepare_enable(clk);
> +       if (ret) {
> +               dev_err(&pdev->dev, "failed to enable clock\n");
> +               goto err_platform_device_put;
> +       }
> +
> +       musb->dev.parent                = &pdev->dev;
> +
> +       glue->dev                       = &pdev->dev;
> +       glue->musb                      = musb;
> +       glue->clk                       = clk;
> +
> +       pdata->platform_ops             = &jz4740_musb_ops;
> +
> +       platform_set_drvdata(pdev, glue);
> +
> +       ret = platform_device_add_resources(musb, pdev->resource,
> +                                           pdev->num_resources);
> +       if (ret) {
> +               dev_err(&pdev->dev, "failed to add resources\n");
> +               goto err_clk_disable;
> +       }
> +
> +       ret = platform_device_add_data(musb, pdata, sizeof(*pdata));
> +       if (ret) {
> +               dev_err(&pdev->dev, "failed to add platform_data\n");
> +               goto err_clk_disable;
> +       }
> +
> +       ret = platform_device_add(musb);
> +       if (ret) {
> +               dev_err(&pdev->dev, "failed to register musb device\n");
> +               goto err_clk_disable;
> +       }
> +
> +       return 0;
> +
> +err_clk_disable:
> +       clk_disable_unprepare(clk);
> +err_platform_device_put:
> +       platform_device_put(musb);
> +       return ret;
> +}
> +
> +static int jz4740_remove(struct platform_device *pdev)
> +{
> +       struct jz4740_glue      *glue = platform_get_drvdata(pdev);
> +
> +       platform_device_unregister(glue->musb);
> +       clk_disable_unprepare(glue->clk);
> +
> +       return 0;
> +}
> +
> +static struct platform_driver jz4740_driver = {
> +       .probe          = jz4740_probe,
> +       .remove         = jz4740_remove,
> +       .driver         = {
> +               .name   = "musb-jz4740",
> +       },
> +};
> +
> +MODULE_DESCRIPTION("JZ4740 MUSB Glue Layer");
> +MODULE_AUTHOR("Apelete Seketeli <apelete@seketeli.net>");
> +MODULE_LICENSE("GPL v2");
> +module_platform_driver(jz4740_driver);
> --
> 1.7.10.4
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
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-- 
Thanks,
//richard

Re: [PATCH v3 1/2] usb: musb: add support for JZ4740 usb device controller

[Apelete Seketeli]

On 04-Jan-14, Richard Weinberger wrote:
> On Thu, Dec 19, 2013 at 9:42 PM, Apelete Seketeli <apelete@seketeli.net> wrote:
> > Add support for Ingenic JZ4740 USB Device Controller through a
> > specific musb glue layer.
> >
> > JZ4740 UDC not being OTG compatible and missing some hardware
> > registers, this musb glue layer is written from scratch to be used in
> > gadget mode only and take silicon design specifics into account.
> >
> > Signed-off-by: Apelete Seketeli <apelete@seketeli.net>
> > Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
> > ---
> >  drivers/usb/musb/Kconfig  |    8 +-
> >  drivers/usb/musb/Makefile |    1 +
> >  drivers/usb/musb/jz4740.c |  201 +++++++++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 209 insertions(+), 1 deletion(-)
> >  create mode 100644 drivers/usb/musb/jz4740.c
> >
> > diff --git a/drivers/usb/musb/Kconfig b/drivers/usb/musb/Kconfig
> > index 57dfc0c..14d7e72 100644
> > --- a/drivers/usb/musb/Kconfig
> > +++ b/drivers/usb/musb/Kconfig
> > @@ -93,6 +93,12 @@ config USB_MUSB_BLACKFIN
> >  config USB_MUSB_UX500
> >         tristate "Ux500 platforms"
> >
> > +config USB_MUSB_JZ4740
> > +       tristate "JZ4740"
> > +       depends on MACH_JZ4740 || COMPILE_TEST
> > +       depends on USB_MUSB_GADGET
> > +       depends on USB_OTG_BLACKLIST_HUB
> > +
> >  endchoice
> >
> >  config USB_MUSB_AM335X_CHILD
> > @@ -100,7 +106,7 @@ config USB_MUSB_AM335X_CHILD
> >
> >  choice
> >         prompt 'MUSB DMA mode'
> > -       default MUSB_PIO_ONLY if ARCH_MULTIPLATFORM
> > +       default MUSB_PIO_ONLY if ARCH_MULTIPLATFORM || USB_MUSB_JZ4740
> 
> Just out of curiosity, why can't we use DMA?

We wrote the musb glue layer for the Ben Nanonote handheld computer
only to provide ethernet-over-usb functionality.

I was thinking about adding DMA support later, but Lars-Peter Clausen
did experiment with DMA, and found out that all ethernet packets were
unaligned, while the DMA only works if they are aligned.
As a consequence, the DMA was bypassed all the time, making it useless
at least for the ethernet gadget we are interested in.

That's why DMA didn't make it into the glue layer.

Cheers.
-- 
        Apelete

Re: [PATCH v3 1/2] usb: musb: add support for JZ4740 usb device controller

[Richard Weinberger]

Am Samstag, 4. Januar 2014, 12:06:22 schrieb Apelete Seketeli:
> On 04-Jan-14, Richard Weinberger wrote:
> > On Thu, Dec 19, 2013 at 9:42 PM, Apelete Seketeli <apelete@seketeli.net> 
wrote:
> > > Add support for Ingenic JZ4740 USB Device Controller through a
> > > specific musb glue layer.
> > > 
> > > JZ4740 UDC not being OTG compatible and missing some hardware
> > > registers, this musb glue layer is written from scratch to be used in
> > > gadget mode only and take silicon design specifics into account.
> > > 
> > > Signed-off-by: Apelete Seketeli <apelete@seketeli.net>
> > > Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
> > > ---
> > > 
> > >  drivers/usb/musb/Kconfig  |    8 +-
> > >  drivers/usb/musb/Makefile |    1 +
> > >  drivers/usb/musb/jz4740.c |  201
> > >  +++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 209
> > >  insertions(+), 1 deletion(-)
> > >  create mode 100644 drivers/usb/musb/jz4740.c
> > > 
> > > diff --git a/drivers/usb/musb/Kconfig b/drivers/usb/musb/Kconfig
> > > index 57dfc0c..14d7e72 100644
> > > --- a/drivers/usb/musb/Kconfig
> > > +++ b/drivers/usb/musb/Kconfig
> > > @@ -93,6 +93,12 @@ config USB_MUSB_BLACKFIN
> > > 
> > >  config USB_MUSB_UX500
> > >  
> > >         tristate "Ux500 platforms"
> > > 
> > > +config USB_MUSB_JZ4740
> > > +       tristate "JZ4740"
> > > +       depends on MACH_JZ4740 || COMPILE_TEST
> > > +       depends on USB_MUSB_GADGET
> > > +       depends on USB_OTG_BLACKLIST_HUB
> > > +
> > > 
> > >  endchoice
> > >  
> > >  config USB_MUSB_AM335X_CHILD
> > > 
> > > @@ -100,7 +106,7 @@ config USB_MUSB_AM335X_CHILD
> > > 
> > >  choice
> > >  
> > >         prompt 'MUSB DMA mode'
> > > 
> > > -       default MUSB_PIO_ONLY if ARCH_MULTIPLATFORM
> > > +       default MUSB_PIO_ONLY if ARCH_MULTIPLATFORM || USB_MUSB_JZ4740
> > 
> > Just out of curiosity, why can't we use DMA?
> 
> We wrote the musb glue layer for the Ben Nanonote handheld computer
> only to provide ethernet-over-usb functionality.
> 
> I was thinking about adding DMA support later, but Lars-Peter Clausen
> did experiment with DMA, and found out that all ethernet packets were
> unaligned, while the DMA only works if they are aligned.
> As a consequence, the DMA was bypassed all the time, making it useless
> at least for the ethernet gadget we are interested in.
> 
> That's why DMA didn't make it into the glue layer.

DMA support would be nice to have.
Especially to make the USB storage gadget work well with the Ben NanoNote.

Thanks,
//richard

Re: [PATCH v3 1/2] usb: musb: add support for JZ4740 usb device controller

[Lars-Peter Clausen]

On 01/04/2014 12:11 PM, Richard Weinberger wrote:
> Am Samstag, 4. Januar 2014, 12:06:22 schrieb Apelete Seketeli:
>> On 04-Jan-14, Richard Weinberger wrote:
>>> On Thu, Dec 19, 2013 at 9:42 PM, Apelete Seketeli <apelete@seketeli.net>
> wrote:
>>>> Add support for Ingenic JZ4740 USB Device Controller through a
>>>> specific musb glue layer.
>>>>
>>>> JZ4740 UDC not being OTG compatible and missing some hardware
>>>> registers, this musb glue layer is written from scratch to be used in
>>>> gadget mode only and take silicon design specifics into account.
>>>>
>>>> Signed-off-by: Apelete Seketeli <apelete@seketeli.net>
>>>> Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
>>>> ---
>>>>
>>>>   drivers/usb/musb/Kconfig  |    8 +-
>>>>   drivers/usb/musb/Makefile |    1 +
>>>>   drivers/usb/musb/jz4740.c |  201
>>>>   +++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 209
>>>>   insertions(+), 1 deletion(-)
>>>>   create mode 100644 drivers/usb/musb/jz4740.c
>>>>
>>>> diff --git a/drivers/usb/musb/Kconfig b/drivers/usb/musb/Kconfig
>>>> index 57dfc0c..14d7e72 100644
>>>> --- a/drivers/usb/musb/Kconfig
>>>> +++ b/drivers/usb/musb/Kconfig
>>>> @@ -93,6 +93,12 @@ config USB_MUSB_BLACKFIN
>>>>
>>>>   config USB_MUSB_UX500
>>>>
>>>>          tristate "Ux500 platforms"
>>>>
>>>> +config USB_MUSB_JZ4740
>>>> +       tristate "JZ4740"
>>>> +       depends on MACH_JZ4740 || COMPILE_TEST
>>>> +       depends on USB_MUSB_GADGET
>>>> +       depends on USB_OTG_BLACKLIST_HUB
>>>> +
>>>>
>>>>   endchoice
>>>>
>>>>   config USB_MUSB_AM335X_CHILD
>>>>
>>>> @@ -100,7 +106,7 @@ config USB_MUSB_AM335X_CHILD
>>>>
>>>>   choice
>>>>
>>>>          prompt 'MUSB DMA mode'
>>>>
>>>> -       default MUSB_PIO_ONLY if ARCH_MULTIPLATFORM
>>>> +       default MUSB_PIO_ONLY if ARCH_MULTIPLATFORM || USB_MUSB_JZ4740
>>>
>>> Just out of curiosity, why can't we use DMA?
>>
>> We wrote the musb glue layer for the Ben Nanonote handheld computer
>> only to provide ethernet-over-usb functionality.
>>
>> I was thinking about adding DMA support later, but Lars-Peter Clausen
>> did experiment with DMA, and found out that all ethernet packets were
>> unaligned, while the DMA only works if they are aligned.
>> As a consequence, the DMA was bypassed all the time, making it useless
>> at least for the ethernet gadget we are interested in.
>>
>> That's why DMA didn't make it into the glue layer.
>
> DMA support would be nice to have.
> Especially to make the USB storage gadget work well with the Ben NanoNote.
>

It is not clear at this point how well the DMA works. While there seems support 
for DMA, there is no documentation about it in the datasheet, which might 
indicate that it is broken. So we first need to make sure that it works 
reliable before we can enable it.

- Lars