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Subject[PATCH] phy: rcar-gen3-usb2: add sysfs for usb role swap
Date
This patch adds sysfs "otg_inputs" for usb role swap. This parameter
is write-only and if you use them as the following, you can swap
the usb role.

For example:
1) connect a usb cable using 2 salvator-x boards
2) On A-device (as host), you input the following command:
# echo a_bus_req/ > /sys/devices/platform/soc/ee080200.usb-phy/otg_inputs
3) On B-device (as peripheral), you input the following command:
# echo b_bus_req > /sys/devices/platform/soc/ee080200.usb-phy/otg_inputs

Then, the A-device acts as a peripheral (A-peripheral) and the B-device
acts as a host (B-host).
Please note that A-device must input the following command if you
want the board to act as a host again. (even if you disconnect the usb
cable, since id state may be the same, the condition keeps "A-peripheral".)
# echo a_bus_drop > /sys/devices/platform/soc/ee080200.usb-phy/otg_inputs

Also you can use the following command if you want the B-device board to
act as a peripheral again.
# echo b_bus_req/ > /sys/devices/platform/soc/ee080200.usb-phy/otg_inputs

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
---
This patch is based on the linux-phy.git / phy-for-4.9-resolved_v3 tag.
(commit id = c4b0bf82f705747ed7de90c5736b07248cbb29cd)

.../ABI/testing/sysfs-platform-phy-rcar-gen3-usb2 | 11 ++
drivers/phy/phy-rcar-gen3-usb2.c | 124 ++++++++++++++++++++-
2 files changed, 134 insertions(+), 1 deletion(-)
create mode 100644 Documentation/ABI/testing/sysfs-platform-phy-rcar-gen3-usb2

diff --git a/Documentation/ABI/testing/sysfs-platform-phy-rcar-gen3-usb2 b/Documentation/ABI/testing/sysfs-platform-phy-rcar-gen3-usb2
new file mode 100644
index 0000000..c7e715af
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-platform-phy-rcar-gen3-usb2
@@ -0,0 +1,11 @@
+What: /sys/devices/platform/<phy-name>/otg-inputs
+Date: October 2016
+KernelVersion: 4.10
+Contact: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
+Description:
+ This write-only file changes the phy mode for role swap of usb.
+ This file accepts the following strings:
+ "a_bus_req/" - switching from A-Host to A-Peripheral
+ "a_bus_drop" - switching from A-Peripheral to A-Host
+ "b_bus_req" - switching from B-Peripheral to B-Host
+ "b_bus_req/" - switching from B-Host to B-Peripheral
diff --git a/drivers/phy/phy-rcar-gen3-usb2.c b/drivers/phy/phy-rcar-gen3-usb2.c
index 3d97ead..80f5bcc 100644
--- a/drivers/phy/phy-rcar-gen3-usb2.c
+++ b/drivers/phy/phy-rcar-gen3-usb2.c
@@ -70,6 +70,7 @@
#define USB2_LINECTRL1_DP_RPD BIT(18)
#define USB2_LINECTRL1_DMRPD_EN BIT(17)
#define USB2_LINECTRL1_DM_RPD BIT(16)
+#define USB2_LINECTRL1_OPMODE_NODRV BIT(6)

/* ADPCTRL */
#define USB2_ADPCTRL_OTGSESSVLD BIT(20)
@@ -161,6 +162,43 @@ static void rcar_gen3_init_for_peri(struct rcar_gen3_chan *ch)
schedule_work(&ch->work);
}

+static void rcar_gen3_init_for_b_host(struct rcar_gen3_chan *ch)
+{
+ void __iomem *usb2_base = ch->base;
+ u32 val;
+
+ val = readl(usb2_base + USB2_LINECTRL1);
+ writel(val | USB2_LINECTRL1_OPMODE_NODRV, usb2_base + USB2_LINECTRL1);
+
+ rcar_gen3_set_linectrl(ch, 1, 1);
+ rcar_gen3_set_host_mode(ch, 1);
+ rcar_gen3_enable_vbus_ctrl(ch, 0);
+
+ val = readl(usb2_base + USB2_LINECTRL1);
+ writel(val & ~USB2_LINECTRL1_OPMODE_NODRV, usb2_base + USB2_LINECTRL1);
+}
+
+static void rcar_gen3_init_for_a_peri(struct rcar_gen3_chan *ch)
+{
+ rcar_gen3_set_linectrl(ch, 0, 1);
+ rcar_gen3_set_host_mode(ch, 0);
+ rcar_gen3_enable_vbus_ctrl(ch, 1);
+}
+
+static void rcar_gen3_init_from_a_peri_to_a_host(struct rcar_gen3_chan *ch)
+{
+ void __iomem *usb2_base = ch->base;
+ u32 val;
+
+ val = readl(usb2_base + USB2_OBINTEN);
+ writel(val & ~USB2_OBINT_BITS, usb2_base + USB2_OBINTEN);
+
+ rcar_gen3_enable_vbus_ctrl(ch, 0);
+ rcar_gen3_init_for_host(ch);
+
+ writel(val | USB2_OBINT_BITS, usb2_base + USB2_OBINTEN);
+}
+
static bool rcar_gen3_check_id(struct rcar_gen3_chan *ch)
{
return !!(readl(ch->base + USB2_ADPCTRL) & USB2_ADPCTRL_IDDIG);
@@ -174,6 +212,71 @@ static void rcar_gen3_device_recognition(struct rcar_gen3_chan *ch)
rcar_gen3_init_for_peri(ch);
}

+/*
+ * The following table is a state transition for usb phy mode:
+ * State Event Next state
+ * disconnected: E1 a_host
+ * E2 b_peripheral
+ * A-Device - a_host: E2 b_peripheral
+ * E3 disconnected
+ * E4 a_suspend
+ * A-Device - a_suspend: E2 b_peripheral
+ * E3 disconnected
+ * E5 a_host
+ * E6 a_peripheral
+ * A-Device - a_peripheral: E2 b_peripheral
+ * E3 disconnected
+ * E5 a_host
+ * B-Device - b_peripheral: E3 disconnected
+ * E7 b_wait_acon
+ * B-Device - b_wait_acon E3 disconnected
+ * E8 b_host
+ * B-Device - b_host: E3 disconnected
+ * E9 b_peripheral
+ * Events:
+ * E1: ID = 0 && Host detects D+ pull up, E2: ID = 1 && VBUS = 1
+ * E3: VBUS = 0 || ID is changed, E4: a_bus_req/
+ * E5: a_bus_drop, E6: Turns D+ pull up off
+ * E7: b_bus_req, E8: Detects D+ pull up
+ * E9: b_bus_req/
+ */
+static ssize_t otg_inputs_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct rcar_gen3_chan *ch = dev_get_drvdata(dev);
+ bool is_host, is_b_device;
+
+ if (!ch->has_otg || !ch->phy->init_count)
+ return -EIO;
+
+ is_b_device = rcar_gen3_check_id(ch); /* true = B-Device */
+ is_host = !(readl(ch->base + USB2_COMMCTRL) & USB2_COMMCTRL_OTG_PERI);
+
+ if (!strncmp(buf, "a_bus_req/", strlen("a_bus_req/"))) {
+ if (is_b_device) /* fail if B-device */
+ return -ENODEV;
+ rcar_gen3_init_for_a_peri(ch);
+ } else if (!strncmp(buf, "a_bus_drop", strlen("a_bus_drop"))) {
+ if (is_b_device || is_host) /* fail if B-device or A-host */
+ return -ENODEV;
+ rcar_gen3_init_from_a_peri_to_a_host(ch);
+ } else if (!strncmp(buf, "b_bus_req/", strlen("b_bus_req/"))) {
+ if (!is_b_device || !is_host) /* fail if A-device or B-peri */
+ return -ENODEV;
+ rcar_gen3_init_for_peri(ch);
+ } else if (!strncmp(buf, "b_bus_req", strlen("b_bus_req"))) {
+ if (!is_b_device) /* fail if A-device */
+ return -ENODEV;
+ rcar_gen3_init_for_b_host(ch);
+ } else {
+ return -EINVAL;
+ }
+
+ return count;
+}
+static DEVICE_ATTR_WO(otg_inputs);
+
static void rcar_gen3_init_otg(struct rcar_gen3_chan *ch)
{
void __iomem *usb2_base = ch->base;
@@ -351,21 +454,40 @@ static int rcar_gen3_phy_usb2_probe(struct platform_device *pdev)
channel->vbus = NULL;
}

+ platform_set_drvdata(pdev, channel);
phy_set_drvdata(channel->phy, channel);

provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
- if (IS_ERR(provider))
+ if (IS_ERR(provider)) {
dev_err(dev, "Failed to register PHY provider\n");
+ } else if (channel->has_otg) {
+ int ret;
+
+ ret = device_create_file(dev, &dev_attr_otg_inputs);
+ if (ret < 0)
+ return ret;
+ }

return PTR_ERR_OR_ZERO(provider);
}

+static int rcar_gen3_phy_usb2_remove(struct platform_device *pdev)
+{
+ struct rcar_gen3_chan *channel = platform_get_drvdata(pdev);
+
+ if (channel->has_otg)
+ device_remove_file(&pdev->dev, &dev_attr_otg_inputs);
+
+ return 0;
+};
+
static struct platform_driver rcar_gen3_phy_usb2_driver = {
.driver = {
.name = "phy_rcar_gen3_usb2",
.of_match_table = rcar_gen3_phy_usb2_match_table,
},
.probe = rcar_gen3_phy_usb2_probe,
+ .remove = rcar_gen3_phy_usb2_remove,
};
module_platform_driver(rcar_gen3_phy_usb2_driver);

--
1.9.1
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