usb: atmel_usba_udc: Add at91sam9g45 and at91sam9x5 errata handling
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.
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Reported-by: Patrice VILCHEZ <patrice.vilchez@atmel.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
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 @@
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 @@
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 @@
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 @@
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 @@
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 */ }
};