[PATCH v3 0/5] usb: atmel_usba_udc: Rework errata handling

[PATCH v3 0/5] usb: atmel_usba_udc: Rework errata handling

[Boris Brezillon]

Hello,

Here is a set of patches porting existing at91sam9rl erratum handling to
DT and adding new code to handle at91sam9g45/9x5 erratum.
It also adds several compatible strings to differentiate those errata.

These patches should be backported to 3.17 and 3.18 stable releases but
they do not apply cleanly on those stable branches.
I'll send a backport of this series once it is merged in mainline.

Regards,

Boris

Changes since v2:
- remove UTF8 character in commit message of patch 2

Changes since v1:
- cache INT_ENB value to speedup INT_ENB read operations

Boris Brezillon (5):
  usb: atmel_usba_udc: Rework at91sam9rl errata handling
  usb: atmel_usba_udc: Add at91sam9g45 and at91sam9x5 errata handling
  ARM: at91/dt: update udc compatible strings
  usb: atmel_usba_udc: Mask status with enabled irqs
  usb: gadget: atmel_usba: Cache INT_ENB register value

 .../devicetree/bindings/usb/atmel-usb.txt          |   5 +-
 arch/arm/boot/dts/at91sam9g45.dtsi                 |   2 +-
 arch/arm/boot/dts/at91sam9x5.dtsi                  |   2 +-
 arch/arm/boot/dts/sama5d3.dtsi                     |   2 +-
 arch/arm/boot/dts/sama5d4.dtsi                     |   2 +-
 drivers/usb/gadget/udc/atmel_usba_udc.c            | 146 +++++++++++++--------
 drivers/usb/gadget/udc/atmel_usba_udc.h            |   9 ++
 7 files changed, 111 insertions(+), 57 deletions(-)

-- 
1.9.1

[PATCH v3 1/5] usb: atmel_usba_udc: Rework at91sam9rl errata handling

[Boris Brezillon]

at91sam9rl SoC has an erratum forcing us to toggle the BIAS on USB
suspend/resume events.

This specific handling is only activated when CONFIG_ARCH_AT91SAM9RL is
set and this option is only set when building a non-DT kernel, which is
problematic since non-DT support for at91sam9rl SoC has been removed.

Rework the toggle_bias implementation to attach it to the "at91sam9rl-udc"
compatible string.

Add new compatible strings to avoid executing at91sam9rl erratum handling
on other SoCs.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
 .../devicetree/bindings/usb/atmel-usb.txt          |  5 +-
 drivers/usb/gadget/udc/atmel_usba_udc.c            | 78 ++++++++++++----------
 drivers/usb/gadget/udc/atmel_usba_udc.h            |  5 ++
 3 files changed, 52 insertions(+), 36 deletions(-)

diff --git a/Documentation/devicetree/bindings/usb/atmel-usb.txt b/Documentation/devicetree/bindings/usb/atmel-usb.txt
index bc2222c..38fee0f 100644
--- a/Documentation/devicetree/bindings/usb/atmel-usb.txt
+++ b/Documentation/devicetree/bindings/usb/atmel-usb.txt
@@ -51,7 +51,10 @@ usb1: gadget at fffa4000 {
 Atmel High-Speed USB device controller
 
 Required properties:
- - compatible: Should be "atmel,at91sam9rl-udc"
+ - compatible: Should be one of the following
+	       "at91sam9rl-udc"
+	       "at91sam9g45-udc"
+	       "sama5d3-udc"
  - reg: Address and length of the register set for the device
  - interrupts: Should contain usba interrupt
  - ep childnode: To specify the number of endpoints and their properties.
diff --git a/drivers/usb/gadget/udc/atmel_usba_udc.c b/drivers/usb/gadget/udc/atmel_usba_udc.c
index ce88237..36fd34b 100644
--- a/drivers/usb/gadget/udc/atmel_usba_udc.c
+++ b/drivers/usb/gadget/udc/atmel_usba_udc.c
@@ -8,6 +8,7 @@
  * published by the Free Software Foundation.
  */
 #include <linux/clk.h>
+#include <linux/clk/at91_pmc.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
@@ -324,28 +325,12 @@ static int vbus_is_present(struct usba_udc *udc)
 	return 1;
 }
 
-#if defined(CONFIG_ARCH_AT91SAM9RL)
-
-#include <linux/clk/at91_pmc.h>
-
-static void toggle_bias(int is_on)
-{
-	unsigned int uckr = at91_pmc_read(AT91_CKGR_UCKR);
-
-	if (is_on)
-		at91_pmc_write(AT91_CKGR_UCKR, uckr | AT91_PMC_BIASEN);
-	else
-		at91_pmc_write(AT91_CKGR_UCKR, uckr & ~(AT91_PMC_BIASEN));
-}
-
-#else
-
-static void toggle_bias(int is_on)
+static void toggle_bias(struct usba_udc *udc, int is_on)
 {
+	if (udc->errata && udc->errata->toggle_bias)
+		udc->errata->toggle_bias(udc, is_on);
 }
 
-#endif /* CONFIG_ARCH_AT91SAM9RL */
-
 static void next_fifo_transaction(struct usba_ep *ep, struct usba_request *req)
 {
 	unsigned int transaction_len;
@@ -1620,7 +1605,7 @@ static irqreturn_t usba_udc_irq(int irq, void *devid)
 	DBG(DBG_INT, "irq, status=%#08x\n", status);
 
 	if (status & USBA_DET_SUSPEND) {
-		toggle_bias(0);
+		toggle_bias(udc, 0);
 		usba_writel(udc, INT_CLR, USBA_DET_SUSPEND);
 		DBG(DBG_BUS, "Suspend detected\n");
 		if (udc->gadget.speed != USB_SPEED_UNKNOWN
@@ -1632,7 +1617,7 @@ static irqreturn_t usba_udc_irq(int irq, void *devid)
 	}
 
 	if (status & USBA_WAKE_UP) {
-		toggle_bias(1);
+		toggle_bias(udc, 1);
 		usba_writel(udc, INT_CLR, USBA_WAKE_UP);
 		DBG(DBG_BUS, "Wake Up CPU detected\n");
 	}
@@ -1736,13 +1721,13 @@ static irqreturn_t usba_vbus_irq(int irq, void *devid)
 	vbus = vbus_is_present(udc);
 	if (vbus != udc->vbus_prev) {
 		if (vbus) {
-			toggle_bias(1);
+			toggle_bias(udc, 1);
 			usba_writel(udc, CTRL, USBA_ENABLE_MASK);
 			usba_writel(udc, INT_ENB, USBA_END_OF_RESET);
 		} else {
 			udc->gadget.speed = USB_SPEED_UNKNOWN;
 			reset_all_endpoints(udc);
-			toggle_bias(0);
+			toggle_bias(udc, 0);
 			usba_writel(udc, CTRL, USBA_DISABLE_MASK);
 			if (udc->driver->disconnect) {
 				spin_unlock(&udc->lock);
@@ -1788,7 +1773,7 @@ static int atmel_usba_start(struct usb_gadget *gadget,
 	/* If Vbus is present, enable the controller and wait for reset */
 	spin_lock_irqsave(&udc->lock, flags);
 	if (vbus_is_present(udc) && udc->vbus_prev == 0) {
-		toggle_bias(1);
+		toggle_bias(udc, 1);
 		usba_writel(udc, CTRL, USBA_ENABLE_MASK);
 		usba_writel(udc, INT_ENB, USBA_END_OF_RESET);
 	}
@@ -1811,7 +1796,7 @@ static int atmel_usba_stop(struct usb_gadget *gadget)
 	spin_unlock_irqrestore(&udc->lock, flags);
 
 	/* This will also disable the DP pullup */
-	toggle_bias(0);
+	toggle_bias(udc, 0);
 	usba_writel(udc, CTRL, USBA_DISABLE_MASK);
 
 	clk_disable_unprepare(udc->hclk);
@@ -1823,6 +1808,29 @@ static int atmel_usba_stop(struct usb_gadget *gadget)
 }
 
 #ifdef CONFIG_OF
+static void at91sam9rl_toggle_bias(struct usba_udc *udc, int is_on)
+{
+	unsigned int uckr = at91_pmc_read(AT91_CKGR_UCKR);
+
+	if (is_on)
+		at91_pmc_write(AT91_CKGR_UCKR, uckr | AT91_PMC_BIASEN);
+	else
+		at91_pmc_write(AT91_CKGR_UCKR, uckr & ~(AT91_PMC_BIASEN));
+}
+
+static const struct usba_udc_errata at91sam9rl_errata = {
+	.toggle_bias = at91sam9rl_toggle_bias,
+};
+
+static const struct of_device_id atmel_udc_dt_ids[] = {
+	{ .compatible = "atmel,at91sam9rl-udc", .data = &at91sam9rl_errata },
+	{ .compatible = "atmel,at91sam9g45-udc" },
+	{ .compatible = "atmel,sama5d3-udc" },
+	{ /* sentinel */ }
+};
+
+MODULE_DEVICE_TABLE(of, atmel_udc_dt_ids);
+
 static struct usba_ep * atmel_udc_of_init(struct platform_device *pdev,
 						    struct usba_udc *udc)
 {
@@ -1830,10 +1838,17 @@ static struct usba_ep * atmel_udc_of_init(struct platform_device *pdev,
 	const char *name;
 	enum of_gpio_flags flags;
 	struct device_node *np = pdev->dev.of_node;
+	const struct of_device_id *match;
 	struct device_node *pp;
 	int i, ret;
 	struct usba_ep *eps, *ep;
 
+	match = of_match_node(atmel_udc_dt_ids, np);
+	if (!match)
+		return ERR_PTR(-EINVAL);
+
+	udc->errata = match->data;
+
 	udc->num_ep = 0;
 
 	udc->vbus_pin = of_get_named_gpio_flags(np, "atmel,vbus-gpio", 0,
@@ -2024,7 +2039,7 @@ static int usba_udc_probe(struct platform_device *pdev)
 		dev_err(&pdev->dev, "Unable to enable pclk, aborting.\n");
 		return ret;
 	}
-	toggle_bias(0);
+
 	usba_writel(udc, CTRL, USBA_DISABLE_MASK);
 	clk_disable_unprepare(pclk);
 
@@ -2033,6 +2048,8 @@ static int usba_udc_probe(struct platform_device *pdev)
 	else
 		udc->usba_ep = usba_udc_pdata(pdev, udc);
 
+	toggle_bias(udc, 0);
+
 	if (IS_ERR(udc->usba_ep))
 		return PTR_ERR(udc->usba_ep);
 
@@ -2092,15 +2109,6 @@ static int __exit usba_udc_remove(struct platform_device *pdev)
 	return 0;
 }
 
-#if defined(CONFIG_OF)
-static const struct of_device_id atmel_udc_dt_ids[] = {
-	{ .compatible = "atmel,at91sam9rl-udc" },
-	{ /* sentinel */ }
-};
-
-MODULE_DEVICE_TABLE(of, atmel_udc_dt_ids);
-#endif
-
 static struct platform_driver udc_driver = {
 	.remove		= __exit_p(usba_udc_remove),
 	.driver		= {
diff --git a/drivers/usb/gadget/udc/atmel_usba_udc.h b/drivers/usb/gadget/udc/atmel_usba_udc.h
index a70706e..456899e 100644
--- a/drivers/usb/gadget/udc/atmel_usba_udc.h
+++ b/drivers/usb/gadget/udc/atmel_usba_udc.h
@@ -304,6 +304,10 @@ struct usba_request {
 	unsigned int				mapped:1;
 };
 
+struct usba_udc_errata {
+	void (*toggle_bias)(struct usba_udc *udc, int is_on);
+};
+
 struct usba_udc {
 	/* Protect hw registers from concurrent modifications */
 	spinlock_t lock;
@@ -314,6 +318,7 @@ struct usba_udc {
 	struct usb_gadget gadget;
 	struct usb_gadget_driver *driver;
 	struct platform_device *pdev;
+	const struct usba_udc_errata *errata;
 	int irq;
 	int vbus_pin;
 	int vbus_pin_inverted;
-- 
1.9.1

[PATCH v3 1/5] usb: atmel_usba_udc: Rework at91sam9rl errata handling

[Paul Bolle]

On Mon, 2015-01-12 at 11:57 +0100, Boris Brezillon wrote:
> at91sam9rl SoC has an erratum forcing us to toggle the BIAS on USB
> suspend/resume events.
> 
> This specific handling is only activated when CONFIG_ARCH_AT91SAM9RL is
> set and this option is only set when building a non-DT kernel, which is
> problematic since non-DT support for at91sam9rl SoC has been removed.

This sentence is not entirely correct. Commit bcf8c7e7703b ("ARM: at91:
remove at91sam9rl legacy board support") actually removed the Kconfig
symbol ARCH_AT91SAM9RL entirely. So the check for CONFIG_ARCH_AT91SAM9RL
has been pointless since (next-20141110 and) v3.19-rc1. See my report at
https://lkml.org/lkml/2014/11/10/232 .

(I stumbled on this patch because I contemplated sending a patch to
simply remove the check for CONFIG_ARCH_AT91SAM9RL and the currently
useless function toggle_bias.)

> Rework the toggle_bias implementation to attach it to the "at91sam9rl-udc"
> compatible string.
> 
> Add new compatible strings to avoid executing at91sam9rl erratum handling
> on other SoCs.
> 
> Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
> Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>


Paul Bolle

[PATCH v3 1/5] usb: atmel_usba_udc: Rework at91sam9rl errata handling

[Boris Brezillon]

Hi Paul,

On Mon, 12 Jan 2015 13:15:58 +0100
Paul Bolle <pebolle@tiscali.nl> wrote:

> On Mon, 2015-01-12 at 11:57 +0100, Boris Brezillon wrote:
> > at91sam9rl SoC has an erratum forcing us to toggle the BIAS on USB
> > suspend/resume events.
> > 
> > This specific handling is only activated when CONFIG_ARCH_AT91SAM9RL is
> > set and this option is only set when building a non-DT kernel, which is
> > problematic since non-DT support for at91sam9rl SoC has been removed.
> 
> This sentence is not entirely correct. Commit bcf8c7e7703b ("ARM: at91:
> remove at91sam9rl legacy board support") actually removed the Kconfig
> symbol ARCH_AT91SAM9RL entirely. So the check for CONFIG_ARCH_AT91SAM9RL
> has been pointless since (next-20141110 and) v3.19-rc1. See my report at
> https://lkml.org/lkml/2014/11/10/232 .

I'll rework my commit message.

> 
> (I stumbled on this patch because I contemplated sending a patch to
> simply remove the check for CONFIG_ARCH_AT91SAM9RL and the currently
> useless function toggle_bias.)

Sorry, I forgot to add you in Cc of this series :-(, I'll do it it for
the future iterations.

Best Regards,

Boris

-- 
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

[PATCH v3 2/5] usb: atmel_usba_udc: Add at91sam9g45 and at91sam9x5 errata handling

[Boris Brezillon]

at91sam9g45 and at91sam9x5 SoCs have an hardware bug forcing us to
generate a pulse on the BIAS signal on "USB end of reset" and
"USB end of resume" events.

Reported-by: Patrice VILCHEZ <patrice.vilchez@atmel.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
 drivers/usb/gadget/udc/atmel_usba_udc.c | 28 +++++++++++++++++++++++++++-
 drivers/usb/gadget/udc/atmel_usba_udc.h |  2 ++
 2 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/gadget/udc/atmel_usba_udc.c b/drivers/usb/gadget/udc/atmel_usba_udc.c
index 36fd34b..55c8dde 100644
--- a/drivers/usb/gadget/udc/atmel_usba_udc.c
+++ b/drivers/usb/gadget/udc/atmel_usba_udc.c
@@ -331,6 +331,17 @@ static void toggle_bias(struct usba_udc *udc, int is_on)
 		udc->errata->toggle_bias(udc, is_on);
 }
 
+static void generate_bias_pulse(struct usba_udc *udc)
+{
+	if (!udc->bias_pulse_needed)
+		return;
+
+	if (udc->errata && udc->errata->pulse_bias)
+		udc->errata->pulse_bias(udc);
+
+	udc->bias_pulse_needed = false;
+}
+
 static void next_fifo_transaction(struct usba_ep *ep, struct usba_request *req)
 {
 	unsigned int transaction_len;
@@ -1607,6 +1618,7 @@ static irqreturn_t usba_udc_irq(int irq, void *devid)
 	if (status & USBA_DET_SUSPEND) {
 		toggle_bias(udc, 0);
 		usba_writel(udc, INT_CLR, USBA_DET_SUSPEND);
+		udc->bias_pulse_needed = true;
 		DBG(DBG_BUS, "Suspend detected\n");
 		if (udc->gadget.speed != USB_SPEED_UNKNOWN
 				&& udc->driver && udc->driver->suspend) {
@@ -1624,6 +1636,7 @@ static irqreturn_t usba_udc_irq(int irq, void *devid)
 
 	if (status & USBA_END_OF_RESUME) {
 		usba_writel(udc, INT_CLR, USBA_END_OF_RESUME);
+		generate_bias_pulse(udc);
 		DBG(DBG_BUS, "Resume detected\n");
 		if (udc->gadget.speed != USB_SPEED_UNKNOWN
 				&& udc->driver && udc->driver->resume) {
@@ -1659,6 +1672,7 @@ static irqreturn_t usba_udc_irq(int irq, void *devid)
 		struct usba_ep *ep0;
 
 		usba_writel(udc, INT_CLR, USBA_END_OF_RESET);
+		generate_bias_pulse(udc);
 		reset_all_endpoints(udc);
 
 		if (udc->gadget.speed != USB_SPEED_UNKNOWN && udc->driver) {
@@ -1818,13 +1832,25 @@ static void at91sam9rl_toggle_bias(struct usba_udc *udc, int is_on)
 		at91_pmc_write(AT91_CKGR_UCKR, uckr & ~(AT91_PMC_BIASEN));
 }
 
+static void at91sam9g45_pulse_bias(struct usba_udc *udc)
+{
+	unsigned int uckr = at91_pmc_read(AT91_CKGR_UCKR);
+
+	at91_pmc_write(AT91_CKGR_UCKR, uckr & ~(AT91_PMC_BIASEN));
+	at91_pmc_write(AT91_CKGR_UCKR, uckr | AT91_PMC_BIASEN);
+}
+
 static const struct usba_udc_errata at91sam9rl_errata = {
 	.toggle_bias = at91sam9rl_toggle_bias,
 };
 
+static const struct usba_udc_errata at91sam9g45_errata = {
+	.pulse_bias = at91sam9g45_pulse_bias,
+};
+
 static const struct of_device_id atmel_udc_dt_ids[] = {
 	{ .compatible = "atmel,at91sam9rl-udc", .data = &at91sam9rl_errata },
-	{ .compatible = "atmel,at91sam9g45-udc" },
+	{ .compatible = "atmel,at91sam9g45-udc", .data = &at91sam9g45_errata },
 	{ .compatible = "atmel,sama5d3-udc" },
 	{ /* sentinel */ }
 };
diff --git a/drivers/usb/gadget/udc/atmel_usba_udc.h b/drivers/usb/gadget/udc/atmel_usba_udc.h
index 456899e..72b3537 100644
--- a/drivers/usb/gadget/udc/atmel_usba_udc.h
+++ b/drivers/usb/gadget/udc/atmel_usba_udc.h
@@ -306,6 +306,7 @@ struct usba_request {
 
 struct usba_udc_errata {
 	void (*toggle_bias)(struct usba_udc *udc, int is_on);
+	void (*pulse_bias)(struct usba_udc *udc);
 };
 
 struct usba_udc {
@@ -326,6 +327,7 @@ struct usba_udc {
 	struct clk *pclk;
 	struct clk *hclk;
 	struct usba_ep *usba_ep;
+	bool bias_pulse_needed;
 
 	u16 devstatus;
 
-- 
1.9.1

[PATCH v3 3/5] ARM: at91/dt: update udc compatible strings

[Boris Brezillon]

at91sam9g45, at91sam9x5 and sama5 SoCs should not use
"atmel,at91sam9rl-udc" for their USB device compatible property since
this compatible is attached to a specific hardware bug fix.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
 arch/arm/boot/dts/at91sam9g45.dtsi | 2 +-
 arch/arm/boot/dts/at91sam9x5.dtsi  | 2 +-
 arch/arm/boot/dts/sama5d3.dtsi     | 2 +-
 arch/arm/boot/dts/sama5d4.dtsi     | 2 +-
 4 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/arm/boot/dts/at91sam9g45.dtsi b/arch/arm/boot/dts/at91sam9g45.dtsi
index 2a8da8a..acd90eb 100644
--- a/arch/arm/boot/dts/at91sam9g45.dtsi
+++ b/arch/arm/boot/dts/at91sam9g45.dtsi
@@ -1144,7 +1144,7 @@
 			usb2: gadget at fff78000 {
 				#address-cells = <1>;
 				#size-cells = <0>;
-				compatible = "atmel,at91sam9rl-udc";
+				compatible = "atmel,at91sam9g45-udc";
 				reg = <0x00600000 0x80000
 				       0xfff78000 0x400>;
 				interrupts = <27 IRQ_TYPE_LEVEL_HIGH 0>;
diff --git a/arch/arm/boot/dts/at91sam9x5.dtsi b/arch/arm/boot/dts/at91sam9x5.dtsi
index bbb3ba6..d213147 100644
--- a/arch/arm/boot/dts/at91sam9x5.dtsi
+++ b/arch/arm/boot/dts/at91sam9x5.dtsi
@@ -1057,7 +1057,7 @@
 			usb2: gadget at f803c000 {
 				#address-cells = <1>;
 				#size-cells = <0>;
-				compatible = "atmel,at91sam9rl-udc";
+				compatible = "atmel,at91sam9g45-udc";
 				reg = <0x00500000 0x80000
 				       0xf803c000 0x400>;
 				interrupts = <23 IRQ_TYPE_LEVEL_HIGH 0>;
diff --git a/arch/arm/boot/dts/sama5d3.dtsi b/arch/arm/boot/dts/sama5d3.dtsi
index 5f4144d..2b407a4 100644
--- a/arch/arm/boot/dts/sama5d3.dtsi
+++ b/arch/arm/boot/dts/sama5d3.dtsi
@@ -1264,7 +1264,7 @@
 		usb0: gadget at 00500000 {
 			#address-cells = <1>;
 			#size-cells = <0>;
-			compatible = "atmel,at91sam9rl-udc";
+			compatible = "atmel,sama5d3-udc";
 			reg = <0x00500000 0x100000
 			       0xf8030000 0x4000>;
 			interrupts = <33 IRQ_TYPE_LEVEL_HIGH 2>;
diff --git a/arch/arm/boot/dts/sama5d4.dtsi b/arch/arm/boot/dts/sama5d4.dtsi
index 1b0f30c..52dce24 100644
--- a/arch/arm/boot/dts/sama5d4.dtsi
+++ b/arch/arm/boot/dts/sama5d4.dtsi
@@ -112,7 +112,7 @@
 		usb0: gadget at 00400000 {
 			#address-cells = <1>;
 			#size-cells = <0>;
-			compatible = "atmel,at91sam9rl-udc";
+			compatible = "atmel,sama5d3-udc";
 			reg = <0x00400000 0x100000
 			       0xfc02c000 0x4000>;
 			interrupts = <47 IRQ_TYPE_LEVEL_HIGH 2>;
-- 
1.9.1

[PATCH v3 3/5] ARM: at91/dt: update udc compatible strings

[Felipe Balbi]

On Mon, Jan 12, 2015 at 11:57:56AM +0100, Boris Brezillon wrote:
> at91sam9g45, at91sam9x5 and sama5 SoCs should not use
> "atmel,at91sam9rl-udc" for their USB device compatible property since
> this compatible is attached to a specific hardware bug fix.
> 
> Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
> Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

WARNING: DT compatible string "atmel,at91sam9g45-udc" appears un-documented -- check ./Documentation/devicetree/bindings/
#177: FILE: drivers/usb/gadget/udc/atmel_usba_udc.c:1827:
+       { .compatible = "atmel,at91sam9g45-udc" },

WARNING: DT compatible string "atmel,sama5d3-udc" appears un-documented -- check ./Documentation/devicetree/bindings/
#178: FILE: drivers/usb/gadget/udc/atmel_usba_udc.c:1828:
+       { .compatible = "atmel,sama5d3-udc" },

please fix and resend. Also, when resending, could you add Nicolas'
Acked-by since he's already given it ?

Thanks

-- 
balbi
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[PATCH v3 3/5] ARM: at91/dt: update udc compatible strings

[Boris Brezillon]

Hi Felipe,

On Mon, 12 Jan 2015 12:23:49 -0600
Felipe Balbi <balbi@ti.com> wrote:

> On Mon, Jan 12, 2015 at 11:57:56AM +0100, Boris Brezillon wrote:
> > at91sam9g45, at91sam9x5 and sama5 SoCs should not use
> > "atmel,at91sam9rl-udc" for their USB device compatible property since
> > this compatible is attached to a specific hardware bug fix.
> > 
> > Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
> > Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
> 
> WARNING: DT compatible string "atmel,at91sam9g45-udc" appears un-documented -- check ./Documentation/devicetree/bindings/
> #177: FILE: drivers/usb/gadget/udc/atmel_usba_udc.c:1827:
> +       { .compatible = "atmel,at91sam9g45-udc" },
> 
> WARNING: DT compatible string "atmel,sama5d3-udc" appears un-documented -- check ./Documentation/devicetree/bindings/
> #178: FILE: drivers/usb/gadget/udc/atmel_usba_udc.c:1828:
> +       { .compatible = "atmel,sama5d3-udc" },
> 
> please fix and resend. Also, when resending, could you add Nicolas'
> Acked-by since he's already given it ?

Actually these compatible strings are documented in the first patch
(where they were introduced), but I'll send a v4 with Nicolas' ack.

Thanks,

Boris



-- 
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

[PATCH v3 3/5] ARM: at91/dt: update udc compatible strings

[Felipe Balbi]

On Mon, Jan 12, 2015 at 08:18:16PM +0100, Boris Brezillon wrote:
> Hi Felipe,
> 
> On Mon, 12 Jan 2015 12:23:49 -0600
> Felipe Balbi <balbi@ti.com> wrote:
> 
> > On Mon, Jan 12, 2015 at 11:57:56AM +0100, Boris Brezillon wrote:
> > > at91sam9g45, at91sam9x5 and sama5 SoCs should not use
> > > "atmel,at91sam9rl-udc" for their USB device compatible property since
> > > this compatible is attached to a specific hardware bug fix.
> > > 
> > > Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
> > > Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
> > 
> > WARNING: DT compatible string "atmel,at91sam9g45-udc" appears un-documented -- check ./Documentation/devicetree/bindings/
> > #177: FILE: drivers/usb/gadget/udc/atmel_usba_udc.c:1827:
> > +       { .compatible = "atmel,at91sam9g45-udc" },
> > 
> > WARNING: DT compatible string "atmel,sama5d3-udc" appears un-documented -- check ./Documentation/devicetree/bindings/
> > #178: FILE: drivers/usb/gadget/udc/atmel_usba_udc.c:1828:
> > +       { .compatible = "atmel,sama5d3-udc" },
> > 
> > please fix and resend. Also, when resending, could you add Nicolas'
> > Acked-by since he's already given it ?
> 
> Actually these compatible strings are documented in the first patch
> (where they were introduced), but I'll send a v4 with Nicolas' ack.

heh, checkpatch stupidity :-) My bad.

-- 
balbi
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[PATCH v3 3/5] ARM: at91/dt: update udc compatible strings

[Boris Brezillon]

On Mon, 12 Jan 2015 13:31:26 -0600
Felipe Balbi <balbi@ti.com> wrote:

> On Mon, Jan 12, 2015 at 08:18:16PM +0100, Boris Brezillon wrote:
> > Hi Felipe,
> > 
> > On Mon, 12 Jan 2015 12:23:49 -0600
> > Felipe Balbi <balbi@ti.com> wrote:
> > 
> > > On Mon, Jan 12, 2015 at 11:57:56AM +0100, Boris Brezillon wrote:
> > > > at91sam9g45, at91sam9x5 and sama5 SoCs should not use
> > > > "atmel,at91sam9rl-udc" for their USB device compatible property since
> > > > this compatible is attached to a specific hardware bug fix.
> > > > 
> > > > Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
> > > > Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
> > > 
> > > WARNING: DT compatible string "atmel,at91sam9g45-udc" appears un-documented -- check ./Documentation/devicetree/bindings/
> > > #177: FILE: drivers/usb/gadget/udc/atmel_usba_udc.c:1827:
> > > +       { .compatible = "atmel,at91sam9g45-udc" },
> > > 
> > > WARNING: DT compatible string "atmel,sama5d3-udc" appears un-documented -- check ./Documentation/devicetree/bindings/
> > > #178: FILE: drivers/usb/gadget/udc/atmel_usba_udc.c:1828:
> > > +       { .compatible = "atmel,sama5d3-udc" },
> > > 
> > > please fix and resend. Also, when resending, could you add Nicolas'
> > > Acked-by since he's already given it ?
> > 
> > Actually these compatible strings are documented in the first patch
> > (where they were introduced), but I'll send a v4 with Nicolas' ack.
> 
> heh, checkpatch stupidity :-) My bad.
> 

You took v3 of the first patch instead of v4.
Don't know if you can replace it (anyway, that's not such a big deal
since the only change is the commit message)...


-- 
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

[PATCH v3 4/5] usb: atmel_usba_udc: Mask status with enabled irqs

[Boris Brezillon]

Avoid interpreting useless status flags when we're not waiting for such
events by masking the status variable with the interrupt enabled register
value.

Reported-by: Patrice VILCHEZ <patrice.vilchez@atmel.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
 drivers/usb/gadget/udc/atmel_usba_udc.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/gadget/udc/atmel_usba_udc.c b/drivers/usb/gadget/udc/atmel_usba_udc.c
index 55c8dde..bc3a532 100644
--- a/drivers/usb/gadget/udc/atmel_usba_udc.c
+++ b/drivers/usb/gadget/udc/atmel_usba_udc.c
@@ -1612,12 +1612,14 @@ static irqreturn_t usba_udc_irq(int irq, void *devid)
 
 	spin_lock(&udc->lock);
 
-	status = usba_readl(udc, INT_STA);
+	status = usba_readl(udc, INT_STA) & usba_readl(udc, INT_ENB);
 	DBG(DBG_INT, "irq, status=%#08x\n", status);
 
 	if (status & USBA_DET_SUSPEND) {
 		toggle_bias(udc, 0);
 		usba_writel(udc, INT_CLR, USBA_DET_SUSPEND);
+		usba_writel(udc, INT_ENB,
+			    usba_readl(udc, INT_ENB) | USBA_WAKE_UP);
 		udc->bias_pulse_needed = true;
 		DBG(DBG_BUS, "Suspend detected\n");
 		if (udc->gadget.speed != USB_SPEED_UNKNOWN
@@ -1631,6 +1633,8 @@ static irqreturn_t usba_udc_irq(int irq, void *devid)
 	if (status & USBA_WAKE_UP) {
 		toggle_bias(udc, 1);
 		usba_writel(udc, INT_CLR, USBA_WAKE_UP);
+		usba_writel(udc, INT_ENB,
+			    usba_readl(udc, INT_ENB) & ~USBA_WAKE_UP);
 		DBG(DBG_BUS, "Wake Up CPU detected\n");
 	}
 
-- 
1.9.1

[PATCH v3 5/5] usb: gadget: atmel_usba: Cache INT_ENB register value

[Boris Brezillon]

Cache INT_ENB register value in order to avoid uncached iomem access, and
thus improve access time to INT_ENB value.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
 drivers/usb/gadget/udc/atmel_usba_udc.c | 52 ++++++++++++++++++---------------
 drivers/usb/gadget/udc/atmel_usba_udc.h |  2 ++
 2 files changed, 30 insertions(+), 24 deletions(-)

diff --git a/drivers/usb/gadget/udc/atmel_usba_udc.c b/drivers/usb/gadget/udc/atmel_usba_udc.c
index bc3a532..6dfe17b 100644
--- a/drivers/usb/gadget/udc/atmel_usba_udc.c
+++ b/drivers/usb/gadget/udc/atmel_usba_udc.c
@@ -316,6 +316,17 @@ static inline void usba_cleanup_debugfs(struct usba_udc *udc)
 }
 #endif
 
+static inline u32 usba_int_enb_get(struct usba_udc *udc)
+{
+	return udc->int_enb_cache;
+}
+
+static inline void usba_int_enb_set(struct usba_udc *udc, u32 val)
+{
+	usba_writel(udc, INT_ENB, val);
+	udc->int_enb_cache = val;
+}
+
 static int vbus_is_present(struct usba_udc *udc)
 {
 	if (gpio_is_valid(udc->vbus_pin))
@@ -597,16 +608,14 @@ usba_ep_enable(struct usb_ep *_ep, const struct usb_endpoint_descriptor *desc)
 	if (ep->can_dma) {
 		u32 ctrl;
 
-		usba_writel(udc, INT_ENB,
-				(usba_readl(udc, INT_ENB)
-					| USBA_BF(EPT_INT, 1 << ep->index)
-					| USBA_BF(DMA_INT, 1 << ep->index)));
+		usba_int_enb_set(udc, usba_int_enb_get(udc) |
+				      USBA_BF(EPT_INT, 1 << ep->index) |
+				      USBA_BF(DMA_INT, 1 << ep->index));
 		ctrl = USBA_AUTO_VALID | USBA_INTDIS_DMA;
 		usba_ep_writel(ep, CTL_ENB, ctrl);
 	} else {
-		usba_writel(udc, INT_ENB,
-				(usba_readl(udc, INT_ENB)
-					| USBA_BF(EPT_INT, 1 << ep->index)));
+		usba_int_enb_set(udc, usba_int_enb_get(udc) |
+				      USBA_BF(EPT_INT, 1 << ep->index));
 	}
 
 	spin_unlock_irqrestore(&udc->lock, flags);
@@ -614,7 +623,7 @@ usba_ep_enable(struct usb_ep *_ep, const struct usb_endpoint_descriptor *desc)
 	DBG(DBG_HW, "EPT_CFG%d after init: %#08lx\n", ep->index,
 			(unsigned long)usba_ep_readl(ep, CFG));
 	DBG(DBG_HW, "INT_ENB after init: %#08lx\n",
-			(unsigned long)usba_readl(udc, INT_ENB));
+			(unsigned long)usba_int_enb_get(udc));
 
 	return 0;
 }
@@ -650,9 +659,8 @@ static int usba_ep_disable(struct usb_ep *_ep)
 		usba_dma_readl(ep, STATUS);
 	}
 	usba_ep_writel(ep, CTL_DIS, USBA_EPT_ENABLE);
-	usba_writel(udc, INT_ENB,
-			usba_readl(udc, INT_ENB)
-			& ~USBA_BF(EPT_INT, 1 << ep->index));
+	usba_int_enb_set(udc, usba_int_enb_get(udc) &
+			      ~USBA_BF(EPT_INT, 1 << ep->index));
 
 	request_complete_list(ep, &req_list, -ESHUTDOWN);
 
@@ -1606,20 +1614,20 @@ static void usba_dma_irq(struct usba_udc *udc, struct usba_ep *ep)
 static irqreturn_t usba_udc_irq(int irq, void *devid)
 {
 	struct usba_udc *udc = devid;
-	u32 status;
+	u32 status, int_enb;
 	u32 dma_status;
 	u32 ep_status;
 
 	spin_lock(&udc->lock);
 
-	status = usba_readl(udc, INT_STA) & usba_readl(udc, INT_ENB);
+	int_enb = usba_int_enb_get(udc);
+	status = usba_readl(udc, INT_STA) & int_enb;
 	DBG(DBG_INT, "irq, status=%#08x\n", status);
 
 	if (status & USBA_DET_SUSPEND) {
 		toggle_bias(udc, 0);
 		usba_writel(udc, INT_CLR, USBA_DET_SUSPEND);
-		usba_writel(udc, INT_ENB,
-			    usba_readl(udc, INT_ENB) | USBA_WAKE_UP);
+		usba_int_enb_set(udc, int_enb | USBA_WAKE_UP);
 		udc->bias_pulse_needed = true;
 		DBG(DBG_BUS, "Suspend detected\n");
 		if (udc->gadget.speed != USB_SPEED_UNKNOWN
@@ -1633,8 +1641,7 @@ static irqreturn_t usba_udc_irq(int irq, void *devid)
 	if (status & USBA_WAKE_UP) {
 		toggle_bias(udc, 1);
 		usba_writel(udc, INT_CLR, USBA_WAKE_UP);
-		usba_writel(udc, INT_ENB,
-			    usba_readl(udc, INT_ENB) & ~USBA_WAKE_UP);
+		usba_int_enb_set(udc, int_enb & ~USBA_WAKE_UP);
 		DBG(DBG_BUS, "Wake Up CPU detected\n");
 	}
 
@@ -1702,11 +1709,8 @@ static irqreturn_t usba_udc_irq(int irq, void *devid)
 				| USBA_BF(BK_NUMBER, USBA_BK_NUMBER_ONE)));
 		usba_ep_writel(ep0, CTL_ENB,
 				USBA_EPT_ENABLE | USBA_RX_SETUP);
-		usba_writel(udc, INT_ENB,
-				(usba_readl(udc, INT_ENB)
-				| USBA_BF(EPT_INT, 1)
-				| USBA_DET_SUSPEND
-				| USBA_END_OF_RESUME));
+		usba_int_enb_set(udc, int_enb | USBA_BF(EPT_INT, 1) |
+				      USBA_DET_SUSPEND | USBA_END_OF_RESUME);
 
 		/*
 		 * Unclear why we hit this irregularly, e.g. in usbtest,
@@ -1741,7 +1745,7 @@ static irqreturn_t usba_vbus_irq(int irq, void *devid)
 		if (vbus) {
 			toggle_bias(udc, 1);
 			usba_writel(udc, CTRL, USBA_ENABLE_MASK);
-			usba_writel(udc, INT_ENB, USBA_END_OF_RESET);
+			usba_int_enb_set(udc, USBA_END_OF_RESET);
 		} else {
 			udc->gadget.speed = USB_SPEED_UNKNOWN;
 			reset_all_endpoints(udc);
@@ -1793,7 +1797,7 @@ static int atmel_usba_start(struct usb_gadget *gadget,
 	if (vbus_is_present(udc) && udc->vbus_prev == 0) {
 		toggle_bias(udc, 1);
 		usba_writel(udc, CTRL, USBA_ENABLE_MASK);
-		usba_writel(udc, INT_ENB, USBA_END_OF_RESET);
+		usba_int_enb_set(udc, USBA_END_OF_RESET);
 	}
 	spin_unlock_irqrestore(&udc->lock, flags);
 
diff --git a/drivers/usb/gadget/udc/atmel_usba_udc.h b/drivers/usb/gadget/udc/atmel_usba_udc.h
index 72b3537..497cd18 100644
--- a/drivers/usb/gadget/udc/atmel_usba_udc.h
+++ b/drivers/usb/gadget/udc/atmel_usba_udc.h
@@ -334,6 +334,8 @@ struct usba_udc {
 	u16 test_mode;
 	int vbus_prev;
 
+	u32 int_enb_cache;
+
 #ifdef CONFIG_USB_GADGET_DEBUG_FS
 	struct dentry *debugfs_root;
 	struct dentry *debugfs_regs;
-- 
1.9.1

[PATCH v3 0/5] usb: atmel_usba_udc: Rework errata handling

[Nicolas Ferre]

Le 12/01/2015 11:57, Boris Brezillon a ?crit :
> Hello,
> 
> Here is a set of patches porting existing at91sam9rl erratum handling to
> DT and adding new code to handle at91sam9g45/9x5 erratum.
> It also adds several compatible strings to differentiate those errata.
> 
> These patches should be backported to 3.17 and 3.18 stable releases but
> they do not apply cleanly on those stable branches.
> I'll send a backport of this series once it is merged in mainline.
> 
> Regards,
> 
> Boris
> 
> Changes since v2:
> - remove UTF8 character in commit message of patch 2
> 
> Changes since v1:
> - cache INT_ENB value to speedup INT_ENB read operations

To the whole series:

Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>

Thanks.

> Boris Brezillon (5):
>   usb: atmel_usba_udc: Rework at91sam9rl errata handling
>   usb: atmel_usba_udc: Add at91sam9g45 and at91sam9x5 errata handling
>   ARM: at91/dt: update udc compatible strings
>   usb: atmel_usba_udc: Mask status with enabled irqs
>   usb: gadget: atmel_usba: Cache INT_ENB register value
> 
>  .../devicetree/bindings/usb/atmel-usb.txt          |   5 +-
>  arch/arm/boot/dts/at91sam9g45.dtsi                 |   2 +-
>  arch/arm/boot/dts/at91sam9x5.dtsi                  |   2 +-
>  arch/arm/boot/dts/sama5d3.dtsi                     |   2 +-
>  arch/arm/boot/dts/sama5d4.dtsi                     |   2 +-
>  drivers/usb/gadget/udc/atmel_usba_udc.c            | 146 +++++++++++++--------
>  drivers/usb/gadget/udc/atmel_usba_udc.h            |   9 ++
>  7 files changed, 111 insertions(+), 57 deletions(-)
> 


-- 
Nicolas Ferre

[PATCH v4 1/5] usb: atmel_usba_udc: Rework at91sam9rl errata handling

[Boris Brezillon]

at91sam9rl SoC has an erratum forcing us to toggle the BIAS on USB
suspend/resume events.

This specific handling was only activated when CONFIG_ARCH_AT91SAM9RL
was set, but commit bcf8c7e7703b ("ARM: at91: remove at91sam9rl legacy
board support") removed this option.

Rework the toggle_bias implementation to attach it to the "at91sam9rl-udc"
compatible string.

Add new compatible strings to avoid executing at91sam9rl erratum handling
on other SoCs.

Reported-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
---

Changes since v3:
- rework commit message

 .../devicetree/bindings/usb/atmel-usb.txt          |  5 +-
 drivers/usb/gadget/udc/atmel_usba_udc.c            | 78 ++++++++++++----------
 drivers/usb/gadget/udc/atmel_usba_udc.h            |  5 ++
 3 files changed, 52 insertions(+), 36 deletions(-)

diff --git a/Documentation/devicetree/bindings/usb/atmel-usb.txt b/Documentation/devicetree/bindings/usb/atmel-usb.txt
index bc2222c..38fee0f 100644
--- a/Documentation/devicetree/bindings/usb/atmel-usb.txt
+++ b/Documentation/devicetree/bindings/usb/atmel-usb.txt
@@ -51,7 +51,10 @@ usb1: gadget at fffa4000 {
 Atmel High-Speed USB device controller
 
 Required properties:
- - compatible: Should be "atmel,at91sam9rl-udc"
+ - compatible: Should be one of the following
+	       "at91sam9rl-udc"
+	       "at91sam9g45-udc"
+	       "sama5d3-udc"
  - reg: Address and length of the register set for the device
  - interrupts: Should contain usba interrupt
  - ep childnode: To specify the number of endpoints and their properties.
diff --git a/drivers/usb/gadget/udc/atmel_usba_udc.c b/drivers/usb/gadget/udc/atmel_usba_udc.c
index ce88237..36fd34b 100644
--- a/drivers/usb/gadget/udc/atmel_usba_udc.c
+++ b/drivers/usb/gadget/udc/atmel_usba_udc.c
@@ -8,6 +8,7 @@
  * published by the Free Software Foundation.
  */
 #include <linux/clk.h>
+#include <linux/clk/at91_pmc.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
@@ -324,28 +325,12 @@ static int vbus_is_present(struct usba_udc *udc)
 	return 1;
 }
 
-#if defined(CONFIG_ARCH_AT91SAM9RL)
-
-#include <linux/clk/at91_pmc.h>
-
-static void toggle_bias(int is_on)
-{
-	unsigned int uckr = at91_pmc_read(AT91_CKGR_UCKR);
-
-	if (is_on)
-		at91_pmc_write(AT91_CKGR_UCKR, uckr | AT91_PMC_BIASEN);
-	else
-		at91_pmc_write(AT91_CKGR_UCKR, uckr & ~(AT91_PMC_BIASEN));
-}
-
-#else
-
-static void toggle_bias(int is_on)
+static void toggle_bias(struct usba_udc *udc, int is_on)
 {
+	if (udc->errata && udc->errata->toggle_bias)
+		udc->errata->toggle_bias(udc, is_on);
 }
 
-#endif /* CONFIG_ARCH_AT91SAM9RL */
-
 static void next_fifo_transaction(struct usba_ep *ep, struct usba_request *req)
 {
 	unsigned int transaction_len;
@@ -1620,7 +1605,7 @@ static irqreturn_t usba_udc_irq(int irq, void *devid)
 	DBG(DBG_INT, "irq, status=%#08x\n", status);
 
 	if (status & USBA_DET_SUSPEND) {
-		toggle_bias(0);
+		toggle_bias(udc, 0);
 		usba_writel(udc, INT_CLR, USBA_DET_SUSPEND);
 		DBG(DBG_BUS, "Suspend detected\n");
 		if (udc->gadget.speed != USB_SPEED_UNKNOWN
@@ -1632,7 +1617,7 @@ static irqreturn_t usba_udc_irq(int irq, void *devid)
 	}
 
 	if (status & USBA_WAKE_UP) {
-		toggle_bias(1);
+		toggle_bias(udc, 1);
 		usba_writel(udc, INT_CLR, USBA_WAKE_UP);
 		DBG(DBG_BUS, "Wake Up CPU detected\n");
 	}
@@ -1736,13 +1721,13 @@ static irqreturn_t usba_vbus_irq(int irq, void *devid)
 	vbus = vbus_is_present(udc);
 	if (vbus != udc->vbus_prev) {
 		if (vbus) {
-			toggle_bias(1);
+			toggle_bias(udc, 1);
 			usba_writel(udc, CTRL, USBA_ENABLE_MASK);
 			usba_writel(udc, INT_ENB, USBA_END_OF_RESET);
 		} else {
 			udc->gadget.speed = USB_SPEED_UNKNOWN;
 			reset_all_endpoints(udc);
-			toggle_bias(0);
+			toggle_bias(udc, 0);
 			usba_writel(udc, CTRL, USBA_DISABLE_MASK);
 			if (udc->driver->disconnect) {
 				spin_unlock(&udc->lock);
@@ -1788,7 +1773,7 @@ static int atmel_usba_start(struct usb_gadget *gadget,
 	/* If Vbus is present, enable the controller and wait for reset */
 	spin_lock_irqsave(&udc->lock, flags);
 	if (vbus_is_present(udc) && udc->vbus_prev == 0) {
-		toggle_bias(1);
+		toggle_bias(udc, 1);
 		usba_writel(udc, CTRL, USBA_ENABLE_MASK);
 		usba_writel(udc, INT_ENB, USBA_END_OF_RESET);
 	}
@@ -1811,7 +1796,7 @@ static int atmel_usba_stop(struct usb_gadget *gadget)
 	spin_unlock_irqrestore(&udc->lock, flags);
 
 	/* This will also disable the DP pullup */
-	toggle_bias(0);
+	toggle_bias(udc, 0);
 	usba_writel(udc, CTRL, USBA_DISABLE_MASK);
 
 	clk_disable_unprepare(udc->hclk);
@@ -1823,6 +1808,29 @@ static int atmel_usba_stop(struct usb_gadget *gadget)
 }
 
 #ifdef CONFIG_OF
+static void at91sam9rl_toggle_bias(struct usba_udc *udc, int is_on)
+{
+	unsigned int uckr = at91_pmc_read(AT91_CKGR_UCKR);
+
+	if (is_on)
+		at91_pmc_write(AT91_CKGR_UCKR, uckr | AT91_PMC_BIASEN);
+	else
+		at91_pmc_write(AT91_CKGR_UCKR, uckr & ~(AT91_PMC_BIASEN));
+}
+
+static const struct usba_udc_errata at91sam9rl_errata = {
+	.toggle_bias = at91sam9rl_toggle_bias,
+};
+
+static const struct of_device_id atmel_udc_dt_ids[] = {
+	{ .compatible = "atmel,at91sam9rl-udc", .data = &at91sam9rl_errata },
+	{ .compatible = "atmel,at91sam9g45-udc" },
+	{ .compatible = "atmel,sama5d3-udc" },
+	{ /* sentinel */ }
+};
+
+MODULE_DEVICE_TABLE(of, atmel_udc_dt_ids);
+
 static struct usba_ep * atmel_udc_of_init(struct platform_device *pdev,
 						    struct usba_udc *udc)
 {
@@ -1830,10 +1838,17 @@ static struct usba_ep * atmel_udc_of_init(struct platform_device *pdev,
 	const char *name;
 	enum of_gpio_flags flags;
 	struct device_node *np = pdev->dev.of_node;
+	const struct of_device_id *match;
 	struct device_node *pp;
 	int i, ret;
 	struct usba_ep *eps, *ep;
 
+	match = of_match_node(atmel_udc_dt_ids, np);
+	if (!match)
+		return ERR_PTR(-EINVAL);
+
+	udc->errata = match->data;
+
 	udc->num_ep = 0;
 
 	udc->vbus_pin = of_get_named_gpio_flags(np, "atmel,vbus-gpio", 0,
@@ -2024,7 +2039,7 @@ static int usba_udc_probe(struct platform_device *pdev)
 		dev_err(&pdev->dev, "Unable to enable pclk, aborting.\n");
 		return ret;
 	}
-	toggle_bias(0);
+
 	usba_writel(udc, CTRL, USBA_DISABLE_MASK);
 	clk_disable_unprepare(pclk);
 
@@ -2033,6 +2048,8 @@ static int usba_udc_probe(struct platform_device *pdev)
 	else
 		udc->usba_ep = usba_udc_pdata(pdev, udc);
 
+	toggle_bias(udc, 0);
+
 	if (IS_ERR(udc->usba_ep))
 		return PTR_ERR(udc->usba_ep);
 
@@ -2092,15 +2109,6 @@ static int __exit usba_udc_remove(struct platform_device *pdev)
 	return 0;
 }
 
-#if defined(CONFIG_OF)
-static const struct of_device_id atmel_udc_dt_ids[] = {
-	{ .compatible = "atmel,at91sam9rl-udc" },
-	{ /* sentinel */ }
-};
-
-MODULE_DEVICE_TABLE(of, atmel_udc_dt_ids);
-#endif
-
 static struct platform_driver udc_driver = {
 	.remove		= __exit_p(usba_udc_remove),
 	.driver		= {
diff --git a/drivers/usb/gadget/udc/atmel_usba_udc.h b/drivers/usb/gadget/udc/atmel_usba_udc.h
index a70706e..456899e 100644
--- a/drivers/usb/gadget/udc/atmel_usba_udc.h
+++ b/drivers/usb/gadget/udc/atmel_usba_udc.h
@@ -304,6 +304,10 @@ struct usba_request {
 	unsigned int				mapped:1;
 };
 
+struct usba_udc_errata {
+	void (*toggle_bias)(struct usba_udc *udc, int is_on);
+};
+
 struct usba_udc {
 	/* Protect hw registers from concurrent modifications */
 	spinlock_t lock;
@@ -314,6 +318,7 @@ struct usba_udc {
 	struct usb_gadget gadget;
 	struct usb_gadget_driver *driver;
 	struct platform_device *pdev;
+	const struct usba_udc_errata *errata;
 	int irq;
 	int vbus_pin;
 	int vbus_pin_inverted;
-- 
1.9.1

[PATCH v3 0/5] usb: atmel_usba_udc: Rework errata handling

[Bo Shen]

Hi Boris,

On 01/12/2015 06:57 PM, Boris Brezillon wrote:
> Hello,
>
> Here is a set of patches porting existing at91sam9rl erratum handling to
> DT and adding new code to handle at91sam9g45/9x5 erratum.
> It also adds several compatible strings to differentiate those errata.
>
> These patches should be backported to 3.17 and 3.18 stable releases but
> they do not apply cleanly on those stable branches.
> I'll send a backport of this series once it is merged in mainline.
>
> Regards,
>
> Boris
>
> Changes since v2:
> - remove UTF8 character in commit message of patch 2
>
> Changes since v1:
> - cache INT_ENB value to speedup INT_ENB read operations

For the whole series, test OK on at91sam9m10g45ek board with mass 
storage gadget, test OK on sama5d36ek with serial gadget.

Tested-by: Bo Shen <voice.shen@atmel.com>

> Boris Brezillon (5):
>    usb: atmel_usba_udc: Rework at91sam9rl errata handling
>    usb: atmel_usba_udc: Add at91sam9g45 and at91sam9x5 errata handling
>    ARM: at91/dt: update udc compatible strings
>    usb: atmel_usba_udc: Mask status with enabled irqs
>    usb: gadget: atmel_usba: Cache INT_ENB register value
>
>   .../devicetree/bindings/usb/atmel-usb.txt          |   5 +-
>   arch/arm/boot/dts/at91sam9g45.dtsi                 |   2 +-
>   arch/arm/boot/dts/at91sam9x5.dtsi                  |   2 +-
>   arch/arm/boot/dts/sama5d3.dtsi                     |   2 +-
>   arch/arm/boot/dts/sama5d4.dtsi                     |   2 +-
>   drivers/usb/gadget/udc/atmel_usba_udc.c            | 146 +++++++++++++--------
>   drivers/usb/gadget/udc/atmel_usba_udc.h            |   9 ++
>   7 files changed, 111 insertions(+), 57 deletions(-)
>

Best Regards,
Bo Shen