[PATCH 5.19 0613/1157] usb: host: ohci-at91: add support to enter suspend using SMC

Greg Kroah-Hartman
2022-08-16T04:32:28Z

From: Clément Léger <clement.leger@bootlin.com>

[ Upstream commit 1e073e3ed9ff9ec14e7e360ed89a81256d895588 ]

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: Claudiu Beznea <claudiu.beznea@microchip.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Clément Léger <clement.leger@bootlin.com>
Link: https://lore.kernel.org/r/20220607133454.727063-1-clement.leger@bootlin.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/usb/host/ohci-at91.c | 69 ++++++++++++++++++++++++------------
1 file changed, 46 insertions(+), 23 deletions(-)

diff --git a/drivers/usb/host/ohci-at91.c b/drivers/usb/host/ohci-at91.c
index a24aea3d2759..98326465e2dc 100644
--- a/drivers/usb/host/ohci-at91.c
+++ b/drivers/usb/host/ohci-at91.c
@@ -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->sfr_regmap = at91_dt_syscon_sfr();
- if (!ohci_at91->sfr_regmap)
- dev_dbg(dev, "failed to find sfr node\n");
+ 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);
@@ -303,24 +322,30 @@ 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;

- ret = regmap_read(regmap, AT91_SFR_OHCIICR, &regval);
- if (ret)
- return ret;
+ 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;

- if (set)
- regval |= AT91_OHCIICR_USB_SUSPEND;
- else
- regval &= ~AT91_OHCIICR_USB_SUSPEND;
+ if (set)
+ regval |= AT91_OHCIICR_USB_SUSPEND;
+ else
+ regval &= ~AT91_OHCIICR_USB_SUSPEND;

- regmap_write(regmap, AT91_SFR_OHCIICR, regval);
+ 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);
--
2.35.1