Commit 1e073e3e authored by Clément Léger's avatar Clément Léger Committed by Greg Kroah-Hartman
Browse files

usb: host: ohci-at91: add support to enter suspend using SMC 



When Linux is running under OP-TEE, the SFR is set as secured and thus
the AT91_OHCIICR_USB_SUSPEND register isn't accessible. Add a SMC to
do the appropriate call to suspend the controller.
The SMC id is fetched from the device-tree property
"microchip,suspend-smc-id". if present, then the syscon regmap is not
used to enter suspend and a SMC is issued.

Reviewed-by: default avatarClaudiu Beznea <claudiu.beznea@microchip.com>
Acked-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: default avatarClément Léger <clement.leger@bootlin.com>
Link: https://lore.kernel.org/r/20220607133454.727063-1-clement.leger@bootlin.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 302970b4

drivers/usb/host/ohci-at91.c

+46 −23
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
 * This file is licenced under the GPL.

 */



#include <linux/arm-smccc.h>

#include <linux/clk.h>

#include <linux/dma-mapping.h>

#include <linux/gpio/consumer.h>
@@ -55,6 +56,7 @@ struct ohci_at91_priv { 
	bool clocked;

	bool wakeup;		/* Saved wake-up state for resume */

	struct regmap *sfr_regmap;

	u32 suspend_smc_id;

};

/* interface and function clocks; sometimes also an AHB clock */
@@ -135,6 +137,19 @@ static void at91_stop_hc(struct platform_device *pdev) 


static void usb_hcd_at91_remove (struct usb_hcd *, struct platform_device *);



static u32 at91_dt_suspend_smc(struct device *dev)

{

	u32 suspend_smc_id;



	if (!dev->of_node)

		return 0;



	if (of_property_read_u32(dev->of_node, "microchip,suspend-smc-id", &suspend_smc_id))

		return 0;



	return suspend_smc_id;

}



static struct regmap *at91_dt_syscon_sfr(void)

{

	struct regmap *regmap;
@@ -215,9 +230,13 @@ static int usb_hcd_at91_probe(const struct hc_driver *driver, 
		goto err;

	}



	ohci_at91->suspend_smc_id = at91_dt_suspend_smc(dev);

	if (!ohci_at91->suspend_smc_id)  {

		dev_dbg(dev, "failed to find sfr suspend smc id, using regmap\n");

		ohci_at91->sfr_regmap = at91_dt_syscon_sfr();

		if (!ohci_at91->sfr_regmap)

			dev_dbg(dev, "failed to find sfr node\n");

	}



	board = hcd->self.controller->platform_data;

	ohci = hcd_to_ohci(hcd);
@@ -303,14 +322,19 @@ static int ohci_at91_hub_status_data(struct usb_hcd *hcd, char *buf) 
	return length;

}



static int ohci_at91_port_suspend(struct regmap *regmap, u8 set)

static int ohci_at91_port_suspend(struct ohci_at91_priv *ohci_at91, u8 set)

{

	struct regmap *regmap = ohci_at91->sfr_regmap;

	u32 regval;

	int ret;



	if (!regmap)

		return 0;

	if (ohci_at91->suspend_smc_id) {

		struct arm_smccc_res res;



		arm_smccc_smc(ohci_at91->suspend_smc_id, set, 0, 0, 0, 0, 0, 0, &res);

		if (res.a0)

			return -EINVAL;

	} else if (regmap) {

		ret = regmap_read(regmap, AT91_SFR_OHCIICR, &regval);

		if (ret)

			return ret;
@@ -321,6 +345,7 @@ static int ohci_at91_port_suspend(struct regmap *regmap, u8 set) 
			regval &= ~AT91_OHCIICR_USB_SUSPEND;



		regmap_write(regmap, AT91_SFR_OHCIICR, regval);

	}



	return 0;

}
@@ -357,9 +382,8 @@ static int ohci_at91_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue, 


		case USB_PORT_FEAT_SUSPEND:

			dev_dbg(hcd->self.controller, "SetPortFeat: SUSPEND\n");

			if (valid_port(wIndex) && ohci_at91->sfr_regmap) {

				ohci_at91_port_suspend(ohci_at91->sfr_regmap,

						       1);

			if (valid_port(wIndex)) {

				ohci_at91_port_suspend(ohci_at91, 1);

				return 0;

			}

			break;
@@ -400,9 +424,8 @@ static int ohci_at91_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue, 


		case USB_PORT_FEAT_SUSPEND:

			dev_dbg(hcd->self.controller, "ClearPortFeature: SUSPEND\n");

			if (valid_port(wIndex) && ohci_at91->sfr_regmap) {

				ohci_at91_port_suspend(ohci_at91->sfr_regmap,

						       0);

			if (valid_port(wIndex)) {

				ohci_at91_port_suspend(ohci_at91, 0);

				return 0;

			}

			break;
@@ -630,10 +653,10 @@ ohci_hcd_at91_drv_suspend(struct device *dev) 
		/* flush the writes */

		(void) ohci_readl (ohci, &ohci->regs->control);

		msleep(1);

		ohci_at91_port_suspend(ohci_at91->sfr_regmap, 1);

		ohci_at91_port_suspend(ohci_at91, 1);

		at91_stop_clock(ohci_at91);

	} else {

		ohci_at91_port_suspend(ohci_at91->sfr_regmap, 1);

		ohci_at91_port_suspend(ohci_at91, 1);

	}



	return ret;
@@ -645,7 +668,7 @@ ohci_hcd_at91_drv_resume(struct device *dev) 
	struct usb_hcd	*hcd = dev_get_drvdata(dev);

	struct ohci_at91_priv *ohci_at91 = hcd_to_ohci_at91_priv(hcd);



	ohci_at91_port_suspend(ohci_at91->sfr_regmap, 0);

	ohci_at91_port_suspend(ohci_at91, 0);



	if (ohci_at91->wakeup)

		disable_irq_wake(hcd->irq);