Patchwork [9/9] usb: phy: tegra: Use DT helpers for dr_mode

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Submitter Tuomas Tynkkynen
Date June 28, 2013, 9:37 p.m.
Message ID <1372455427-20898-10-git-send-email-ttynkkynen@nvidia.com>
Download mbox | patch
Permalink /patch/255675/
State Superseded, archived
Headers show

Comments

Tuomas Tynkkynen - June 28, 2013, 9:37 p.m.
Use the new of_usb_get_dr_mode helper function for parsing dr_mode
from the device tree. Also replace the usage of the custom
tegra_usb_phy_mode enum with the standard enum.

Signed-off-by: Tuomas Tynkkynen <ttynkkynen@nvidia.com>
---
 drivers/usb/phy/phy-tegra-usb.c   | 20 ++++++++------------
 include/linux/usb/tegra_usb_phy.h |  8 +-------
 2 files changed, 9 insertions(+), 19 deletions(-)
Stephen Warren - July 1, 2013, 10:02 p.m.
On 06/28/2013 03:37 PM, Tuomas Tynkkynen wrote:
> Use the new of_usb_get_dr_mode helper function for parsing dr_mode
> from the device tree. Also replace the usage of the custom
> tegra_usb_phy_mode enum with the standard enum.

> diff --git a/drivers/usb/phy/phy-tegra-usb.c b/drivers/usb/phy/phy-tegra-usb.c
> +	tegra_phy->mode = of_usb_get_dr_mode(np);
> +	if (tegra_phy->mode == USB_DR_MODE_UNKNOWN) {
> +		dev_err(&pdev->dev, "dr_mode is invalid\n");
> +		return -EINVAL;
> +	}

Unfortunately, of_usb_get_dr_mode() returns USB_DR_MODE_UNKNOWN if the
property is missing, rather than defaulting to host mode as the original
code here did. I would suggest solving this by:

> diff --git a/drivers/usb/usb-common.c b/drivers/usb/usb-common.c
> index 675384d..6391de5 100644
> --- a/drivers/usb/usb-common.c
> +++ b/drivers/usb/usb-common.c
> @@ -103,7 +103,7 @@ enum usb_dr_mode of_usb_get_dr_mode(struct device_node *np)
>  
>         err = of_property_read_string(np, "dr_mode", &dr_mode);
>         if (err < 0)
> -               return USB_DR_MODE_UNKNOWN;
> +               return USB_DR_MODE_HOST;
>  
>         for (i = 0; i < ARRAY_SIZE(usb_dr_modes); i++)
>                 if (!strcmp(dr_mode, usb_dr_modes[i]))

This can't be done by the caller, since of_usb_get_dr_mode() returns
UNKNOWN in two cases, which the caller can't distinguish without
manually checking whether the property exists first:

a) Property is not present (which should default to HOST mode at least
for the Tegra binding, as in the patch I show above).

b) Property is present, but contains an invalid value, which probably
should cause the driver to error-out.

This is only a problem for dr_mode in the Tegra binding: dr_mode is an
optional property, whereas the phy_type property as parsed by patch 8/9
is mandatory, so this issue doesn't come up.
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Patch

diff --git a/drivers/usb/phy/phy-tegra-usb.c b/drivers/usb/phy/phy-tegra-usb.c
index 13049ce..32d4394 100644
--- a/drivers/usb/phy/phy-tegra-usb.c
+++ b/drivers/usb/phy/phy-tegra-usb.c
@@ -377,7 +377,7 @@  static int utmi_phy_power_on(struct tegra_usb_phy *phy)
 		UTMIP_PLLU_ENABLE_DLY_COUNT(phy->freq->enable_delay);
 	writel(val, base + UTMIP_PLL_CFG1);
 
-	if (phy->mode == TEGRA_USB_PHY_MODE_DEVICE) {
+	if (phy->mode == USB_DR_MODE_PERIPHERAL) {
 		val = readl(base + USB_SUSP_CTRL);
 		val &= ~(USB_WAKE_ON_CNNT_EN_DEV | USB_WAKE_ON_DISCON_EN_DEV);
 		writel(val, base + USB_SUSP_CTRL);
@@ -412,7 +412,7 @@  static int utmi_phy_power_on(struct tegra_usb_phy *phy)
 
 	if (phy->is_legacy_phy) {
 		val = readl(base + UTMIP_SPARE_CFG0);
-		if (phy->mode == TEGRA_USB_PHY_MODE_DEVICE)
+		if (phy->mode == USB_DR_MODE_PERIPHERAL)
 			val &= ~FUSE_SETUP_SEL;
 		else
 			val |= FUSE_SETUP_SEL;
@@ -453,7 +453,7 @@  static int utmi_phy_power_off(struct tegra_usb_phy *phy)
 
 	utmi_phy_clk_disable(phy);
 
-	if (phy->mode == TEGRA_USB_PHY_MODE_DEVICE) {
+	if (phy->mode == USB_DR_MODE_PERIPHERAL) {
 		val = readl(base + USB_SUSP_CTRL);
 		val &= ~USB_WAKEUP_DEBOUNCE_COUNT(~0);
 		val |= USB_WAKE_ON_CNNT_EN_DEV | USB_WAKEUP_DEBOUNCE_COUNT(5);
@@ -906,15 +906,11 @@  static int tegra_usb_phy_probe(struct platform_device *pdev)
 		return -EINVAL;
 	}
 
-	err = of_property_match_string(np, "dr_mode", "otg");
-	if (err < 0) {
-		err = of_property_match_string(np, "dr_mode", "peripheral");
-		if (err < 0)
-			tegra_phy->mode = TEGRA_USB_PHY_MODE_HOST;
-		else
-			tegra_phy->mode = TEGRA_USB_PHY_MODE_DEVICE;
-	} else
-		tegra_phy->mode = TEGRA_USB_PHY_MODE_OTG;
+	tegra_phy->mode = of_usb_get_dr_mode(np);
+	if (tegra_phy->mode == USB_DR_MODE_UNKNOWN) {
+		dev_err(&pdev->dev, "dr_mode is invalid\n");
+		return -EINVAL;
+	}
 
 	/* On some boards, the VBUS regulator doesn't need to be controlled */
 	if (of_find_property(np, "vbus-supply", NULL)) {
diff --git a/include/linux/usb/tegra_usb_phy.h b/include/linux/usb/tegra_usb_phy.h
index a095c98..d3db274 100644
--- a/include/linux/usb/tegra_usb_phy.h
+++ b/include/linux/usb/tegra_usb_phy.h
@@ -34,12 +34,6 @@  enum tegra_usb_phy_port_speed {
 	TEGRA_USB_PHY_PORT_SPEED_HIGH,
 };
 
-enum tegra_usb_phy_mode {
-	TEGRA_USB_PHY_MODE_DEVICE,
-	TEGRA_USB_PHY_MODE_HOST,
-	TEGRA_USB_PHY_MODE_OTG,
-};
-
 struct tegra_xtal_freq;
 
 struct tegra_usb_phy {
@@ -51,7 +45,7 @@  struct tegra_usb_phy {
 	struct clk *pll_u;
 	struct clk *pad_clk;
 	struct regulator *vbus;
-	enum tegra_usb_phy_mode mode;
+	enum usb_dr_mode mode;
 	void *config;
 	struct usb_phy *ulpi;
 	struct usb_phy u_phy;