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

From: Boris Brezillon
Date: Mon Jan 12 2015 - 05:58:12 EST

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@xxxxxxxxxxxxxxxxxx>
Acked-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxxxxxxxxx>
---
.../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@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

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