[PATCH 1/2] at91/USB: Add USB drivers for at91sam9g45 series

[PATCH 1/2] at91/USB: Add USB drivers for at91sam9g45 series

[Nicolas Ferre]

Add both host and gadget USB drivers for at91sam9g45 series. Those SOC embed
high speed USB interfaces.
The gadget driver is the already available atmel_usba_udc.
The host driver is an EHCI with its companion OHCI. EHCI is handled by the new
ehci-atmel.c whereas the OHCI is always handled by ohci-at91.c. This last
wrapper is modified to allow IRQ sharing between two controllers.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
---
 drivers/usb/Kconfig           |    1 +
 drivers/usb/gadget/Kconfig    |    4 +-
 drivers/usb/host/ehci-atmel.c |  251 +++++++++++++++++++++++++++++++++++++++++
 drivers/usb/host/ehci-hcd.c   |    5 +
 drivers/usb/host/ohci-at91.c  |    3 +-
 5 files changed, 261 insertions(+), 3 deletions(-)
 create mode 100644 drivers/usb/host/ehci-atmel.c

diff --git a/drivers/usb/Kconfig b/drivers/usb/Kconfig
index c6c816b..3974c9c 100644
--- a/drivers/usb/Kconfig
+++ b/drivers/usb/Kconfig
@@ -57,6 +57,7 @@ config USB_ARCH_HAS_EHCI
 	default y if PPC_83xx
 	default y if SOC_AU1200
 	default y if ARCH_IXP4XX
+	default y if ARCH_AT91SAM9G45
 	default PCI
 
 # ARM SA1111 chips have a non-PCI based "OHCI-compatible" USB host interface.
diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig
index 080bb1e..9beea52 100644
--- a/drivers/usb/gadget/Kconfig
+++ b/drivers/usb/gadget/Kconfig
@@ -124,7 +124,7 @@ choice
 
 config USB_GADGET_AT91
 	boolean "Atmel AT91 USB Device Port"
-	depends on ARCH_AT91 && !ARCH_AT91SAM9RL && !ARCH_AT91CAP9
+	depends on ARCH_AT91 && !ARCH_AT91SAM9RL && !ARCH_AT91CAP9 && !ARCH_AT91SAM9G45
 	select USB_GADGET_SELECTED
 	help
 	   Many Atmel AT91 processors (such as the AT91RM2000) have a
@@ -143,7 +143,7 @@ config USB_AT91
 config USB_GADGET_ATMEL_USBA
 	boolean "Atmel USBA"
 	select USB_GADGET_DUALSPEED
-	depends on AVR32 || ARCH_AT91CAP9 || ARCH_AT91SAM9RL
+	depends on AVR32 || ARCH_AT91CAP9 || ARCH_AT91SAM9RL || ARCH_AT91SAM9G45
 	help
 	  USBA is the integrated high-speed USB Device controller on
 	  the AT32AP700x, some AT91SAM9 and AT91CAP9 processors from Atmel.
diff --git a/drivers/usb/host/ehci-atmel.c b/drivers/usb/host/ehci-atmel.c
new file mode 100644
index 0000000..c5f2303
--- /dev/null
+++ b/drivers/usb/host/ehci-atmel.c
@@ -0,0 +1,251 @@
+/*
+ * Driver for EHCI UHP on Atmel chips
+ *
+ *  Copyright (C) 2009 Atmel Corporation,
+ *                     Nicolas Ferre <nicolas.ferre@atmel.com>
+ *
+ *  Based on various ehci-*.c drivers
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file COPYING in the main directory of this archive for
+ * more details.
+ */
+
+#include <linux/clk.h>
+#include <linux/platform_device.h>
+
+/* interface and function clocks */
+static struct clk *iclk, *fclk;
+static int clocked;
+
+/*-------------------------------------------------------------------------*/
+
+static void atmel_start_clock(void)
+{
+	clk_enable(iclk);
+	clk_enable(fclk);
+	clocked = 1;
+}
+
+static void atmel_stop_clock(void)
+{
+	clk_disable(fclk);
+	clk_disable(iclk);
+	clocked = 0;
+}
+
+static void atmel_start_ehci(struct platform_device *pdev)
+{
+
+	dev_dbg(&pdev->dev, "start\n");
+
+	/*
+	 * Start the USB clocks.
+	 */
+	atmel_start_clock();
+}
+
+static void atmel_stop_ehci(struct platform_device *pdev)
+{
+	dev_dbg(&pdev->dev, "stop\n");
+
+	/*
+	 * Stop the USB clocks.
+	 */
+	atmel_stop_clock();
+}
+
+/*-------------------------------------------------------------------------*/
+
+static int ehci_atmel_setup(struct usb_hcd *hcd)
+{
+	struct ehci_hcd *ehci = hcd_to_ehci(hcd);
+	int retval = 0;
+
+	/*
+	 * registers start at offset 0x0
+	 */
+	ehci->caps = hcd->regs;
+	ehci->regs = hcd->regs +
+		HC_LENGTH(ehci_readl(ehci, &ehci->caps->hc_capbase));
+	dbg_hcs_params(ehci, "reset");
+	dbg_hcc_params(ehci, "reset");
+
+	/*
+	 * cache this readonly data; minimize chip reads
+	 */
+	ehci->hcs_params = ehci_readl(ehci, &ehci->caps->hcs_params);
+
+	retval = ehci_halt(ehci);
+	if (retval)
+		return retval;
+
+	/*
+	 * data structure init
+	 */
+	retval = ehci_init(hcd);
+	if (retval)
+		return retval;
+
+	ehci->sbrn = 0x20;
+
+	ehci_reset(ehci);
+	ehci_port_power(ehci, 0);
+
+	return retval;
+}
+
+static const struct hc_driver ehci_atmel_hc_driver = {
+	.description		= hcd_name,
+	.product_desc		= "Atmel EHCI UHP HS",
+	.hcd_priv_size		= sizeof(struct ehci_hcd),
+
+	/*
+	 * generic hardware linkage
+	 */
+	.irq			= ehci_irq,
+	.flags			= HCD_MEMORY | HCD_USB2,
+
+	/*
+	 * basic lifecycle operations
+	 */
+	.reset			= ehci_atmel_setup,
+	.start			= ehci_run,
+	.stop			= ehci_stop,
+	.shutdown		= ehci_shutdown,
+
+	/*
+	 * managing i/o requests and associated device resources
+	 */
+	.urb_enqueue		= ehci_urb_enqueue,
+	.urb_dequeue		= ehci_urb_dequeue,
+	.endpoint_disable	= ehci_endpoint_disable,
+
+	/*
+	 * scheduling support
+	 */
+	.get_frame_number	= ehci_get_frame,
+
+	/*
+	 * root hub support
+	 */
+	.hub_status_data	= ehci_hub_status_data,
+	.hub_control		= ehci_hub_control,
+	.bus_suspend		= ehci_bus_suspend,
+	.bus_resume		= ehci_bus_resume,
+	.relinquish_port	= ehci_relinquish_port,
+	.port_handed_over	= ehci_port_handed_over,
+};
+
+static int __init ehci_atmel_drv_probe(struct platform_device *pdev)
+{
+	struct usb_hcd *hcd;
+	const struct hc_driver *driver = &ehci_atmel_hc_driver;
+	struct resource *res;
+	int irq;
+	int retval;
+
+	if (usb_disabled())
+		return -ENODEV;
+
+	pr_debug("Initializing Atmel-SoC USB Host Controller\n");
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq <= 0) {
+		dev_err(&pdev->dev,
+			"Found HC with no IRQ. Check %s setup!\n",
+			dev_name(&pdev->dev));
+		retval = -ENODEV;
+		goto fail_create_hcd;
+	}
+
+	hcd = usb_create_hcd(driver, &pdev->dev, dev_name(&pdev->dev));
+	if (!hcd) {
+		retval = -ENOMEM;
+		goto fail_create_hcd;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev,
+			"Found HC with no register addr. Check %s setup!\n",
+			dev_name(&pdev->dev));
+		retval = -ENODEV;
+		goto fail_request_resource;
+	}
+	hcd->rsrc_start = res->start;
+	hcd->rsrc_len = res->end - res->start + 1;
+
+	if (!request_mem_region(hcd->rsrc_start, hcd->rsrc_len,
+				driver->description)) {
+		dev_dbg(&pdev->dev, "controller already in use\n");
+		retval = -EBUSY;
+		goto fail_request_resource;
+	}
+
+	hcd->regs = ioremap_nocache(hcd->rsrc_start, hcd->rsrc_len);
+	if (hcd->regs == NULL) {
+		dev_dbg(&pdev->dev, "error mapping memory\n");
+		retval = -EFAULT;
+		goto fail_ioremap;
+	}
+
+	iclk = clk_get(&pdev->dev, "ehci_clk");
+	fclk = clk_get(&pdev->dev, "uhpck");
+	if (IS_ERR(iclk) || IS_ERR(fclk)) {
+		dev_err(&pdev->dev, "Error getting clocks\n");
+		retval = -ENOENT;
+		goto fail_get_clk;
+	}
+
+	atmel_start_ehci(pdev);
+
+	retval = usb_add_hcd(hcd, irq, IRQF_SHARED);
+	if (retval)
+		goto fail_add_hcd;
+
+	return retval;
+
+fail_add_hcd:
+	atmel_stop_ehci(pdev);
+fail_get_clk:
+	clk_put(fclk);
+	clk_put(iclk);
+	iounmap(hcd->regs);
+fail_ioremap:
+	release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
+fail_request_resource:
+	usb_put_hcd(hcd);
+fail_create_hcd:
+	dev_err(&pdev->dev, "init %s fail, %d\n",
+		dev_name(&pdev->dev), retval);
+
+	return retval;
+}
+
+static int __exit ehci_atmel_drv_remove(struct platform_device *pdev)
+{
+	struct usb_hcd *hcd = platform_get_drvdata(pdev);
+
+	ehci_shutdown(hcd);
+	usb_remove_hcd(hcd);
+	iounmap(hcd->regs);
+	release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
+	usb_put_hcd(hcd);
+
+	atmel_stop_ehci(pdev);
+	clk_put(fclk);
+	clk_put(iclk);
+	fclk = iclk = NULL;
+
+	return 0;
+}
+
+MODULE_ALIAS("platform:atmel-ehci");
+
+static struct platform_driver ehci_atmel_driver = {
+	.probe		= ehci_atmel_drv_probe,
+	.remove		= __exit_p(ehci_atmel_drv_remove),
+	.shutdown	= usb_hcd_platform_shutdown,
+	.driver.name	= "atmel-ehci",
+};
diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index c637207..df2ddee 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -1072,6 +1072,11 @@ MODULE_LICENSE ("GPL");
 #define	PLATFORM_DRIVER		ixp4xx_ehci_driver
 #endif
 
+#ifdef CONFIG_ARCH_AT91
+#include "ehci-atmel.c"
+#define	PLATFORM_DRIVER		ehci_atmel_driver
+#endif
+
 #if !defined(PCI_DRIVER) && !defined(PLATFORM_DRIVER) && \
     !defined(PS3_SYSTEM_BUS_DRIVER) && !defined(OF_PLATFORM_DRIVER)
 #error "missing bus glue for ehci-hcd"
diff --git a/drivers/usb/host/ohci-at91.c b/drivers/usb/host/ohci-at91.c
index bb5e6f6..b29b0fe 100644
--- a/drivers/usb/host/ohci-at91.c
+++ b/drivers/usb/host/ohci-at91.c
@@ -148,7 +148,8 @@ static int usb_hcd_at91_probe(const struct hc_driver *driver,
 	at91_start_hc(pdev);
 	ohci_hcd_init(hcd_to_ohci(hcd));
 
-	retval = usb_add_hcd(hcd, pdev->resource[1].start, IRQF_DISABLED);
+	retval = usb_add_hcd(hcd, pdev->resource[1].start,
+				IRQF_DISABLED | IRQF_SHARED);
 	if (retval == 0)
 		return retval;
 
-- 
1.5.3.7

Re: [PATCH 1/2] at91/USB: Add USB drivers for at91sam9g45 series

[Nicolas Ferre]

Hi,

Ryan Mallon :
> Nicolas Ferre wrote:
>> Add both host and gadget USB drivers for at91sam9g45 series. Those SOC embed
>> high speed USB interfaces.
>> The gadget driver is the already available atmel_usba_udc.
>> The host driver is an EHCI with its companion OHCI. EHCI is handled by the new
>> ehci-atmel.c whereas the OHCI is always handled by ohci-at91.c. This last
>> wrapper is modified to allow IRQ sharing between two controllers.
>>
>> Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
> 
> Some comments below.

Thanks a lot for them.

>> ---
>> diff --git a/drivers/usb/host/ehci-atmel.c b/drivers/usb/host/ehci-atmel.c
>> new file mode 100644
>> index 0000000..c5f2303
>> --- /dev/null
>> +++ b/drivers/usb/host/ehci-atmel.c
>> @@ -0,0 +1,251 @@
>> +/*
>> + * Driver for EHCI UHP on Atmel chips
>> + *
>> + *  Copyright (C) 2009 Atmel Corporation,
>> + *                     Nicolas Ferre <nicolas.ferre@atmel.com>
>> + *
>> + *  Based on various ehci-*.c drivers
>> + *
>> + * This file is subject to the terms and conditions of the GNU General Public
>> + * License.  See the file COPYING in the main directory of this archive for
>> + * more details.
>> + */
>> +
>> +#include <linux/clk.h>
>> +#include <linux/platform_device.h>
>> +
>> +/* interface and function clocks */
>> +static struct clk *iclk, *fclk;
>> +static int clocked;
>> +
>> +/*-------------------------------------------------------------------------*/
>> +
>> +static void atmel_start_clock(void)
>> +{
>> +	clk_enable(iclk);
>> +	clk_enable(fclk);
>> +	clocked = 1;
>> +}
>> +
>> +static void atmel_stop_clock(void)
>> +{
>> +	clk_disable(fclk);
>> +	clk_disable(iclk);
>> +	clocked = 0;
>> +}
>> +
>> +static void atmel_start_ehci(struct platform_device *pdev)
>> +{
>> +
>> +	dev_dbg(&pdev->dev, "start\n");
>> +
>> +	/*
>> +	 * Start the USB clocks.
>> +	 */
>> +	atmel_start_clock();
>> +}
> 
> The clocked variable is never used outside of the start/stop functions.
> How come you have separate functions, why not just:
> 
> static void atmel_start_ehci(struct platform_device *pdev)
> {
> 	dev_dbg(&pdev->dev, "start\n");
> 	clk_enable(iclk);
> 	clk_enable(fclk);
> }
> 
> and similarly for the atmel_stop_ehci function. Also, currently these
> are only called from the probe/remove functions, so you could just move
> the clock enable/disable into those, or have you separated these out so
> that can eventually be called from pm_suspend/resume functions?

I must say that this creation of clock management function comes from an
habit of sharing drivers between AVR32 and AT91; moreover between
different kind of AT91 devices that share different clock management
schemes (Cf. at91sam9261 vs other sam9 chips).
Experience has taught me that separating clock management in a single
function set ease things.
You are right also that this may be useful for power management.

For all this I prefer to keep them.

>> +
>> +static void atmel_stop_ehci(struct platform_device *pdev)
>> +{
>> +	dev_dbg(&pdev->dev, "stop\n");
>> +
>> +	/*
>> +	 * Stop the USB clocks.
>> +	 */
>> +	atmel_stop_clock();
>> +}
>> +
>> +/*-------------------------------------------------------------------------*/
> 
> Probably don't need this comment.

Totally agree. Those start/stop comments are useless.


>> +
>> +static int ehci_atmel_setup(struct usb_hcd *hcd)
>> +{
>> +	struct ehci_hcd *ehci = hcd_to_ehci(hcd);
>> +	int retval = 0;
>> +
>> +	/*
>> +	 * registers start at offset 0x0
>> +	 */
>> +	ehci->caps = hcd->regs;
>> +	ehci->regs = hcd->regs +
>> +		HC_LENGTH(ehci_readl(ehci, &ehci->caps->hc_capbase));
>> +	dbg_hcs_params(ehci, "reset");
>> +	dbg_hcc_params(ehci, "reset");
>> +
>> +	/*
>> +	 * cache this readonly data; minimize chip reads
>> +	 */
>> +	ehci->hcs_params = ehci_readl(ehci, &ehci->caps->hcs_params);
>> +
>> +	retval = ehci_halt(ehci);
>> +	if (retval)
>> +		return retval;
>> +
>> +	/*
>> +	 * data structure init
>> +	 */
>> +	retval = ehci_init(hcd);
>> +	if (retval)
>> +		return retval;
>> +
>> +	ehci->sbrn = 0x20;
>> +
>> +	ehci_reset(ehci);
>> +	ehci_port_power(ehci, 0);
>> +
>> +	return retval;
>> +}
>> +
>> +static const struct hc_driver ehci_atmel_hc_driver = {
>> +	.description		= hcd_name,
>> +	.product_desc		= "Atmel EHCI UHP HS",
>> +	.hcd_priv_size		= sizeof(struct ehci_hcd),
>> +
>> +	/*
>> +	 * generic hardware linkage
>> +	 */
> 
> Nitpick: put single line comments on single lines.

Ok.

>> +	.irq			= ehci_irq,
>> +	.flags			= HCD_MEMORY | HCD_USB2,
>> +
>> +	/*
>> +	 * basic lifecycle operations
>> +	 */
>> +	.reset			= ehci_atmel_setup,
>> +	.start			= ehci_run,
>> +	.stop			= ehci_stop,
>> +	.shutdown		= ehci_shutdown,
>> +
>> +	/*
>> +	 * managing i/o requests and associated device resources
>> +	 */
>> +	.urb_enqueue		= ehci_urb_enqueue,
>> +	.urb_dequeue		= ehci_urb_dequeue,
>> +	.endpoint_disable	= ehci_endpoint_disable,
>> +
>> +	/*
>> +	 * scheduling support
>> +	 */
>> +	.get_frame_number	= ehci_get_frame,
>> +
>> +	/*
>> +	 * root hub support
>> +	 */
>> +	.hub_status_data	= ehci_hub_status_data,
>> +	.hub_control		= ehci_hub_control,
>> +	.bus_suspend		= ehci_bus_suspend,
>> +	.bus_resume		= ehci_bus_resume,
>> +	.relinquish_port	= ehci_relinquish_port,
>> +	.port_handed_over	= ehci_port_handed_over,
>> +};
>> +
>> +static int __init ehci_atmel_drv_probe(struct platform_device *pdev)
>> +{
>> +	struct usb_hcd *hcd;
>> +	const struct hc_driver *driver = &ehci_atmel_hc_driver;
>> +	struct resource *res;
>> +	int irq;
>> +	int retval;
>> +
>> +	if (usb_disabled())
>> +		return -ENODEV;
>> +
>> +	pr_debug("Initializing Atmel-SoC USB Host Controller\n");
>> +
>> +	irq = platform_get_irq(pdev, 0);
>> +	if (irq <= 0) {
>> +		dev_err(&pdev->dev,
>> +			"Found HC with no IRQ. Check %s setup!\n",
>> +			dev_name(&pdev->dev));
>> +		retval = -ENODEV;
>> +		goto fail_create_hcd;
>> +	}
>> +
>> +	hcd = usb_create_hcd(driver, &pdev->dev, dev_name(&pdev->dev));
>> +	if (!hcd) {
>> +		retval = -ENOMEM;
>> +		goto fail_create_hcd;
>> +	}
>> +
>> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> +	if (!res) {
>> +		dev_err(&pdev->dev,
>> +			"Found HC with no register addr. Check %s setup!\n",
>> +			dev_name(&pdev->dev));
>> +		retval = -ENODEV;
>> +		goto fail_request_resource;
>> +	}
>> +	hcd->rsrc_start = res->start;
>> +	hcd->rsrc_len = res->end - res->start + 1;
>> +
>> +	if (!request_mem_region(hcd->rsrc_start, hcd->rsrc_len,
>> +				driver->description)) {
>> +		dev_dbg(&pdev->dev, "controller already in use\n");
>> +		retval = -EBUSY;
>> +		goto fail_request_resource;
>> +	}
>> +
>> +	hcd->regs = ioremap_nocache(hcd->rsrc_start, hcd->rsrc_len);
>> +	if (hcd->regs == NULL) {
>> +		dev_dbg(&pdev->dev, "error mapping memory\n");
>> +		retval = -EFAULT;
>> +		goto fail_ioremap;
>> +	}
>> +
>> +	iclk = clk_get(&pdev->dev, "ehci_clk");
>> +	fclk = clk_get(&pdev->dev, "uhpck");
>> +	if (IS_ERR(iclk) || IS_ERR(fclk)) {
>> +		dev_err(&pdev->dev, "Error getting clocks\n");
>> +		retval = -ENOENT;
>> +		goto fail_get_clk;
>> +	}
> 
> This doesn't seem right. If one or neither of the clk_gets succeed here
> then you will clk_put a clock which you never got in fail_get_clk. You
> should probably get the two clocks individually an have separate error
> paths for both.

Ok.


Thanks, I will post a modified patch soon.

Best regards,
-- 
Nicolas Ferre