Re: [PATCH] Allow MUSB DSPS to use "force host" mode

From: Felipe Balbi
Date: Mon Nov 25 2013 - 16:25:12 EST

Hi,

On Fri, Nov 22, 2013 at 03:55:59PM +0000, Mark Jackson wrote:
> The IDDIG input pin is normally used to determine the USB mode
> (i.e. HOST or DEVICE).
>
> On some systems (e.g. AM335x) leaving this pin floating allows
> the USB mode to be set via software.
>
> This patch adds support for this via the device tree.
>
> Signed-off-by: Mark Jackson <mpfj@xxxxxxxxxxxxx>
> ---
> .../devicetree/bindings/usb/am33xx-usb.txt | 2 ++
> drivers/usb/musb/musb_dsps.c | 14 ++++++++++++++
> include/linux/usb/musb.h | 1 +
> 3 files changed, 17 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/usb/am33xx-usb.txt b/Documentation/devicetree/bindings/usb/am33xx-usb.txt
> index 20c2ff2..560b7ff 100644
> --- a/Documentation/devicetree/bindings/usb/am33xx-usb.txt
> +++ b/Documentation/devicetree/bindings/usb/am33xx-usb.txt
> @@ -47,6 +47,8 @@ USB
> - dmas: specifies the dma channels
> - dma-names: specifies the names of the channels. Use "rxN" for receive
> and "txN" for transmit endpoints. N specifies the endpoint number.
> +- ti,force-host: specifies that the IDDIG input be ignored and the device be
> + put into host mode regardless.
>
> The controller should have an "usb" alias numbered properly in the alias
> node.
> diff --git a/drivers/usb/musb/musb_dsps.c b/drivers/usb/musb/musb_dsps.c
> index 1901f6f..6439809 100644
> --- a/drivers/usb/musb/musb_dsps.c
> +++ b/drivers/usb/musb/musb_dsps.c
> @@ -105,6 +105,7 @@ struct dsps_musb_wrapper {
> unsigned otg_disable:5;
>
> /* bit positions for mode */
> + unsigned iddig_mux:5;
> unsigned iddig:5;
> /* miscellaneous stuff */
> u8 poll_seconds;
> @@ -387,6 +388,15 @@ static int dsps_musb_init(struct musb *musb)
>
> musb->isr = dsps_interrupt;
>
> + /* Force host mode, rather than relying on IDDIG input */
> + if (musb->config->force_host) {
> + val = dsps_readl(reg_base, wrp->mode);
> + /* clear IDDIG bit, set IDDIG_MUX bit */
> + val &= ~(1 << wrp->iddig);
> + val |= (1 << wrp->iddig_mux);
> + dsps_writel(musb->ctrl_base, wrp->mode, val);
> + }
> +
> /* reset the otgdisable bit, needed for host mode to work */
> val = dsps_readl(reg_base, wrp->phy_utmi);
> val &= ~(1 << wrp->otg_disable);
> @@ -512,6 +522,9 @@ static int dsps_create_musb_pdev(struct dsps_glue *glue,
> pdata.power = get_int_prop(dn, "mentor,power") / 2;
> config->multipoint = of_property_read_bool(dn, "mentor,multipoint");
>
> + if (of_property_read_bool(dn, "ti,force-host"))
> + config->force_host = true;
> +
> ret = platform_device_add_data(musb, &pdata, sizeof(pdata));
> if (ret) {
> dev_err(dev, "failed to add platform_data\n");
> @@ -607,6 +620,7 @@ static const struct dsps_musb_wrapper am33xx_driver_data = {
> .mode = 0xe8,
> .reset = 0,
> .otg_disable = 21,
> + .iddig_mux = 7,

I recently sent a patch to make this work, I'm attaching it here in case
it didn't reach mailing list.

--
balbi
From 5edc4b78bbfdc5fcff2cba46c7dbeebd2efddb76 Mon Sep 17 00:00:00 2001
From: Felipe Balbi <balbi@xxxxxx>
Date: Tue, 29 Oct 2013 12:17:16 -0500
Subject: [PATCH 1/2] usb: musb: dsps: implement ->set_mode()

this will let us support broken designs such
as AM335x EVM SK where ID pin isn't routed
anywhere on a host port.

With this we can toggle internal IDDIG signal
and make sure MUSB goes into host mode as
necessary.

Signed-off-by: Felipe Balbi <balbi@xxxxxx>
---
drivers/usb/musb/musb_dsps.c | 51 ++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 51 insertions(+)

diff --git a/drivers/usb/musb/musb_dsps.c b/drivers/usb/musb/musb_dsps.c
index 1901f6f..ce7ec01 100644
--- a/drivers/usb/musb/musb_dsps.c
+++ b/drivers/usb/musb/musb_dsps.c
@@ -106,6 +106,7 @@ struct dsps_musb_wrapper {

/* bit positions for mode */
unsigned iddig:5;
+ unsigned iddig_mux:5;
/* miscellaneous stuff */
u8 poll_seconds;
};
@@ -406,6 +407,54 @@ static int dsps_musb_exit(struct musb *musb)
return 0;
}

+static int dsps_musb_set_mode(struct musb *musb, u8 mode)
+{
+ struct device *dev = musb->controller;
+ struct dsps_glue *glue = dev_get_drvdata(dev->parent);
+ const struct dsps_musb_wrapper *wrp = glue->wrp;
+ void __iomem *ctrl_base = musb->ctrl_base;
+ void __iomem *base = musb->mregs;
+ u32 reg;
+
+ reg = dsps_readl(base, wrp->mode);
+
+ switch (mode) {
+ case MUSB_HOST:
+ reg &= ~(1 << wrp->iddig);
+
+ /*
+ * if we're setting mode to host-only or device-only, we're
+ * going to ignore whatever the PHY sends us and just force
+ * ID pin status by SW
+ */
+ reg |= (1 << wrp->iddig_mux);
+
+ dsps_writel(base, wrp->mode, reg);
+ dsps_writel(ctrl_base, wrp->phy_utmi, 0x02);
+ break;
+ case MUSB_PERIPHERAL:
+ reg |= (1 << wrp->iddig);
+
+ /*
+ * if we're setting mode to host-only or device-only, we're
+ * going to ignore whatever the PHY sends us and just force
+ * ID pin status by SW
+ */
+ reg |= (1 << wrp->iddig_mux);
+
+ dsps_writel(base, wrp->mode, reg);
+ break;
+ case MUSB_OTG:
+ dsps_writel(base, wrp->phy_utmi, 0x02);
+ break;
+ default:
+ dev_err(glue->dev, "unsupported mode %d\n", mode);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
static struct musb_platform_ops dsps_ops = {
.init = dsps_musb_init,
.exit = dsps_musb_exit,
@@ -414,6 +463,7 @@ static struct musb_platform_ops dsps_ops = {
.disable = dsps_musb_disable,

.try_idle = dsps_musb_try_idle,
+ .set_mode = dsps_musb_set_mode,
};

static u64 musb_dmamask = DMA_BIT_MASK(32);
@@ -608,6 +658,7 @@ static const struct dsps_musb_wrapper am33xx_driver_data = {
.reset = 0,
.otg_disable = 21,
.iddig = 8,
+ .iddig_mux = 7,
.usb_shift = 0,
.usb_mask = 0x1ff,
.usb_bitmap = (0x1ff << 0),
--
1.8.4.GIT

From c9dfe3d2b4c3f00951839eb17835daa0c5c19d71 Mon Sep 17 00:00:00 2001
From: Felipe Balbi <balbi@xxxxxx>
Date: Tue, 29 Oct 2013 12:17:17 -0500
Subject: [PATCH 2/2] usb: musb: core: call musb_platform_set_mode() during
probe

This will tell glue layer which mode we want port
to be in.

Signed-off-by: Felipe Balbi <balbi@xxxxxx>
---
drivers/usb/musb/musb_core.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
index 0a43329..377ef9b 100644
--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -1941,17 +1941,26 @@ musb_init_controller(struct device *dev, int nIrq, void __iomem *ctrl)
switch (musb->port_mode) {
case MUSB_PORT_MODE_HOST:
status = musb_host_setup(musb, plat->power);
+ if (status < 0)
+ goto fail3;
+ status = musb_platform_set_mode(musb, MUSB_HOST);
break;
case MUSB_PORT_MODE_GADGET:
status = musb_gadget_setup(musb);
+ if (status < 0)
+ goto fail3;
+ status = musb_platform_set_mode(musb, MUSB_PERIPHERAL);
break;
case MUSB_PORT_MODE_DUAL_ROLE:
status = musb_host_setup(musb, plat->power);
if (status < 0)
goto fail3;
status = musb_gadget_setup(musb);
- if (status)
+ if (status) {
musb_host_cleanup(musb);
+ goto fail3;
+ }
+ status = musb_platform_set_mode(musb, MUSB_OTG);
break;
default:
dev_err(dev, "unsupported port mode %d\n", musb->port_mode);
--
1.8.4.GIT

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