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usb: chipidea: imx: support configuring for active low oc signal 

The status quo on i.MX6 is that if "over-current-active-high" is
specified in the device tree this is configured as expected. If
the property is missing polarity isn't changed and so the
polarity is kept as setup by the bootloader. Reset default is
active high, so active low can only be used with help by the
bootloader. On i.MX7 it is similar, but there disabling of
over current detection has a similar inconsistency.

This patch introduces a new property that allows to explicitly
configure for active low over current detection and consistently
sets this up. In the absence of an explicit configuration the
bit is kept as is. On i.MX7 over current detection is used unless
disabled in the device tree.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
hifive-unleashed-5.1
Uwe Kleine-König 2018-12-04 09:31:29 +01:00 committed by Peter Chen
parent 4dddb862d3
commit a82bf696aa
4 changed files with 43 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
Documentation/devicetree/bindings/usb/ci-hdrc-usb2.txt
View File

@ -90,8 +90,9 @@ i.mx specific properties
- fsl,usbmisc: phandler of non-core register device, with one
argument that indicate usb controller index
- disable-over-current: disable over current detect
- over-current-active-high: over current signal polarity is high active,
typically over current signal polarity is low active.
- over-current-active-low: over current signal polarity is active low.
- over-current-active-high: over current signal polarity is active high.
It's recommended to specify the over current polarity.
- external-vbus-divider: enables off-chip resistor divider for Vbus
Example:

16
drivers/usb/chipidea/ci_hdrc_imx.c
View File

@ -136,11 +136,19 @@ static struct imx_usbmisc_data *usbmisc_get_init_data(struct device *dev)
data->dev = &misc_pdev->dev;
if (of_find_property(np, "disable-over-current", NULL))
/*
* Check the various over current related properties. If over current
* detection is disabled we're not interested in the polarity.
*/
if (of_find_property(np, "disable-over-current", NULL)) {
data->disable_oc = 1;
if (of_find_property(np, "over-current-active-high", NULL))
data->oc_polarity = 1;
} else if (of_find_property(np, "over-current-active-high", NULL)) {
data->oc_pol_active_low = 0;
data->oc_pol_configured = 1;
} else if (of_find_property(np, "over-current-active-low", NULL)) {
data->oc_pol_active_low = 1;
data->oc_pol_configured = 1;
}
if (of_find_property(np, "external-vbus-divider", NULL))
data->evdo = 1;

8
drivers/usb/chipidea/ci_hdrc_imx.h
View File

@ -11,7 +11,13 @@ struct imx_usbmisc_data {
int index;
unsigned int disable_oc:1; /* over current detect disabled */
unsigned int oc_polarity:1; /* over current polarity if oc enabled */
/* true if over-current polarity is active low */
unsigned int oc_pol_active_low:1;
/* true if dt specifies polarity */
unsigned int oc_pol_configured:1;
unsigned int evdo:1; /* set external vbus divider option */
unsigned int ulpi:1; /* connected to an ULPI phy */
unsigned int hsic:1; /* HSIC controlller */

28
drivers/usb/chipidea/usbmisc_imx.c
View File

@ -356,11 +356,17 @@ static int usbmisc_imx6q_init(struct imx_usbmisc_data *data)
reg = readl(usbmisc->base + data->index * 4);
if (data->disable_oc) {
reg |= MX6_BM_OVER_CUR_DIS;
} else if (data->oc_polarity == 1) {
/* High active */
reg &= ~(MX6_BM_OVER_CUR_DIS | MX6_BM_OVER_CUR_POLARITY);
} else {
reg &= ~(MX6_BM_OVER_CUR_DIS);
reg &= ~MX6_BM_OVER_CUR_DIS;
/*
* If the polarity is not configured keep it as setup by the
* bootloader.
*/
if (data->oc_pol_configured && data->oc_pol_active_low)
reg |= MX6_BM_OVER_CUR_POLARITY;
else if (data->oc_pol_configured)
reg &= ~MX6_BM_OVER_CUR_POLARITY;
}
writel(reg, usbmisc->base + data->index * 4);
@ -552,9 +558,17 @@ static int usbmisc_imx7d_init(struct imx_usbmisc_data *data)
reg = readl(usbmisc->base);
if (data->disable_oc) {
reg |= MX6_BM_OVER_CUR_DIS;
} else if (data->oc_polarity == 1) {
/* High active */
reg &= ~(MX6_BM_OVER_CUR_DIS | MX6_BM_OVER_CUR_POLARITY);
} else {
reg &= ~MX6_BM_OVER_CUR_DIS;
/*
* If the polarity is not configured keep it as setup by the
* bootloader.
*/
if (data->oc_pol_configured && data->oc_pol_active_low)
reg |= MX6_BM_OVER_CUR_POLARITY;
else if (data->oc_pol_configured)
reg &= ~MX6_BM_OVER_CUR_POLARITY;
}
writel(reg, usbmisc->base);