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 36fd34b7738769cb298d41b5675220b8c9cb5f48..55c8dde67f836b0421bfba8bed77c75ce384a4e8 100644 (file)
--- 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 456899e9ee624d801887e97f5fda50ec6564ec90..72b3537f56ced1b22d881ba43d62a7a381bb13db 100644 (file)
--- 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;