On Tue, Nov 01, 2016 at 04:01:58PM +0900, Yoshihiro Shimoda wrote:
> 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 <[email protected]>
> ---
> This patch is based on the latest linux-phy.git / next branch.
> (commit id = 7809cd2ce6abd4f431e4b14e6b1276a7cc842ac4)
>
> Since this patch is related to usb, I added email addresses of Greg, Felipe,
> Peter and USB ML as CC. (This patch doesn't use USB OTG FSM though.)
>
> Changed from v1:
> - rebase the latest next branch.
>
> .../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 <[email protected]>
> +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
Would you really care OTG FSM state machine? If not, you could just use
"host" and "peripheral" to stand for current USB role, and implement
role switch sysfs like: /sys/devices/platform/<phy-name>/role.
Peter
> 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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--
Best Regards,
Peter Chen
