On Thu, Jan 12, 2023 at 10:13 PM Bjorn Andersson
<quic_bjorande@xxxxxxxxxxx> wrote:
>
> From: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
>
> With the PMIC GLINK service, the host OS subscribes to USB-C altmode
> messages, which are sent by the firmware to notify the host OS about
> state updates and HPD interrupts.
>
> The pmic_glink_altmode driver registers for these notifications and
> propagates the notifications as typec_mux, typec_switch and DRM OOB
> notifications as necessary to implement DisplayPort altmode support.
>
> Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
> Signed-off-by: Bjorn Andersson <quic_bjorande@xxxxxxxxxxx>
> ---
>
> Changes since v1:
> - None
>
> Johan reported a NULL pointer dereference in
> drm_kms_helper_hotplug_event() for HPD event being reported while the
> MSM DRM driver is still being initalized, a separate fix has been sent
> in hope to remidy this race condition in the MSM driver.
>
> drivers/soc/qcom/Makefile | 1 +
> drivers/soc/qcom/pmic_glink_altmode.c | 477 ++++++++++++++++++++++++++
> 2 files changed, 478 insertions(+)
> create mode 100644 drivers/soc/qcom/pmic_glink_altmode.c
>
> diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
> index 29cccac472f3..f30552bf4da7 100644
> --- a/drivers/soc/qcom/Makefile
> +++ b/drivers/soc/qcom/Makefile
> @@ -10,6 +10,7 @@ obj-$(CONFIG_QCOM_MDT_LOADER) += mdt_loader.o
> obj-$(CONFIG_QCOM_OCMEM) += ocmem.o
> obj-$(CONFIG_QCOM_PDR_HELPERS) += pdr_interface.o
> obj-$(CONFIG_QCOM_PMIC_GLINK) += pmic_glink.o
> +obj-$(CONFIG_QCOM_PMIC_GLINK) += pmic_glink_altmode.o
> obj-$(CONFIG_QCOM_QMI_HELPERS) += qmi_helpers.o
> qmi_helpers-y += qmi_encdec.o qmi_interface.o
> obj-$(CONFIG_QCOM_RAMP_CTRL) += ramp_controller.o
> diff --git a/drivers/soc/qcom/pmic_glink_altmode.c b/drivers/soc/qcom/pmic_glink_altmode.c
> new file mode 100644
> index 000000000000..8d2d563cb756
> --- /dev/null
> +++ b/drivers/soc/qcom/pmic_glink_altmode.c
> @@ -0,0 +1,477 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2019-2020, The Linux Foundation. All rights reserved.
> + * Copyright (c) 2022, Linaro Ltd
> + */
> +#include <linux/auxiliary_bus.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +#include <linux/mutex.h>
> +#include <linux/property.h>
> +#include <linux/soc/qcom/pdr.h>
> +#include <drm/drm_bridge.h>
> +
> +#include <linux/usb/typec_altmode.h>
> +#include <linux/usb/typec_dp.h>
> +#include <linux/usb/typec_mux.h>
> +
> +#include <linux/soc/qcom/pmic_glink.h>
> +
> +#define PMIC_GLINK_MAX_PORTS 2
> +
> +#define USBC_SC8180X_NOTIFY_IND 0x13
> +#define USBC_CMD_WRITE_REQ 0x15
> +#define USBC_NOTIFY_IND 0x16
> +
> +#define ALTMODE_PAN_EN 0x10
> +#define ALTMODE_PAN_ACK 0x11
> +
> +struct usbc_write_req {
> + struct pmic_glink_hdr hdr;
> + __le32 cmd;
> + __le32 arg;
> + __le32 reserved;
> +};
> +
> +#define NOTIFY_PAYLOAD_SIZE 16
> +struct usbc_notify {
> + struct pmic_glink_hdr hdr;
> + char payload[NOTIFY_PAYLOAD_SIZE];
> + u32 reserved;
> +};
> +
> +struct usbc_sc8180x_notify {
> + struct pmic_glink_hdr hdr;
> + __le32 notification;
> + __le32 reserved[2];
> +};
> +
> +enum pmic_glink_altmode_pin_assignment {
> + DPAM_HPD_OUT,
> + DPAM_HPD_A,
> + DPAM_HPD_B,
> + DPAM_HPD_C,
> + DPAM_HPD_D,
> + DPAM_HPD_E,
> + DPAM_HPD_F,
> +};
> +
> +struct pmic_glink_altmode;
> +
> +#define work_to_altmode_port(w) container_of((w), struct pmic_glink_altmode_port, work)
> +
> +struct pmic_glink_altmode_port {
> + struct pmic_glink_altmode *altmode;
> + unsigned int index;
> +
> + struct typec_switch *typec_switch;
> + struct typec_mux *typec_mux;
> + struct typec_mux_state state;
> + struct typec_altmode dp_alt;
> +
> + struct work_struct work;
> +
> + struct drm_bridge bridge;
> +
> + enum typec_orientation orientation;
> + u16 svid;
> + u8 dp_data;
> + u8 mode;
> + u8 hpd_state;
> + u8 hpd_irq;
> +};
> +
> +#define work_to_altmode(w) container_of((w), struct pmic_glink_altmode, enable_work)
> +
> +struct pmic_glink_altmode {
> + struct device *dev;
> +
> + unsigned int owner_id;
> +
> + /* To synchronize WRITE_REQ acks */
> + struct mutex lock;
> +
> + struct completion pan_ack;
> + struct pmic_glink_client *client;
> +
> + struct work_struct enable_work;
> +
> + struct pmic_glink_altmode_port ports[PMIC_GLINK_MAX_PORTS];
> +};
> +
> +static int pmic_glink_altmode_request(struct pmic_glink_altmode *altmode, u32 cmd, u32 arg)
> +{
> + struct usbc_write_req req = {};
> + unsigned long left;
> + int ret;
> +
> + /*
> + * The USBC_CMD_WRITE_REQ ack doesn't identify the request, so wait for
> + * one ack at a time.
> + */
> + mutex_lock(&altmode->lock);
> +
> + req.hdr.owner = cpu_to_le32(altmode->owner_id);
> + req.hdr.type = cpu_to_le32(PMIC_GLINK_REQ_RESP);
> + req.hdr.opcode = cpu_to_le32(USBC_CMD_WRITE_REQ);
> + req.cmd = cpu_to_le32(cmd);
> + req.arg = cpu_to_le32(arg);
> +
> + ret = pmic_glink_send(altmode->client, &req, sizeof(req));
> + if (ret) {
> + dev_err(altmode->dev, "failed to send altmode request: %#x (%d)\n", cmd, ret);
> + goto out_unlock;
> + }
> +
> + left = wait_for_completion_timeout(&altmode->pan_ack, 5 * HZ);
> + if (!left) {
> + dev_err(altmode->dev, "timeout waiting for altmode request ack for: %#x\n", cmd);
> + ret = -ETIMEDOUT;
> + }
> +
> +out_unlock:
> + mutex_unlock(&altmode->lock);
> + return ret;
> +}
> +
> +static void pmic_glink_altmode_enable_dp(struct pmic_glink_altmode *altmode,
> + struct pmic_glink_altmode_port *port,
> + u8 mode, bool hpd_state,
> + bool hpd_irq)
> +{
> + struct typec_displayport_data dp_data = {};
> + int ret;
> +
> + dp_data.status = DP_STATUS_ENABLED;
> + if (hpd_state)
> + dp_data.status |= DP_STATUS_HPD_STATE;
> + if (hpd_irq)
> + dp_data.status |= DP_STATUS_IRQ_HPD;
> + dp_data.conf = DP_CONF_SET_PIN_ASSIGN(mode);
> +
> + port->state.alt = &port->dp_alt;
> + port->state.data = &dp_data;
> + port->state.mode = TYPEC_MODAL_STATE(mode);
> +
> + ret = typec_mux_set(port->typec_mux, &port->state);
> + if (ret)
> + dev_err(altmode->dev, "failed to switch mux to DP\n");
> +}
> +
> +static void pmic_glink_altmode_enable_usb(struct pmic_glink_altmode *altmode,
> + struct pmic_glink_altmode_port *port)
> +{
> + int ret;
> +
> + port->state.alt = NULL;
> + port->state.data = NULL;
> + port->state.mode = TYPEC_STATE_USB;
> +
> + ret = typec_mux_set(port->typec_mux, &port->state);
> + if (ret)
> + dev_err(altmode->dev, "failed to switch mux to USB\n");
> +}
> +
> +static void pmic_glink_altmode_worker(struct work_struct *work)
> +{
> + struct pmic_glink_altmode_port *alt_port = work_to_altmode_port(work);
> + struct pmic_glink_altmode *altmode = alt_port->altmode;
> +
> + typec_switch_set(alt_port->typec_switch, alt_port->orientation);
> +
> + if (alt_port->svid == USB_TYPEC_DP_SID)
> + pmic_glink_altmode_enable_dp(altmode, alt_port, alt_port->mode,
> + alt_port->hpd_state, alt_port->hpd_irq);
> + else
> + pmic_glink_altmode_enable_usb(altmode, alt_port);
> +
> + if (alt_port->hpd_state)
> + drm_bridge_hpd_notify(&alt_port->bridge, connector_status_connected);
> + else
> + drm_bridge_hpd_notify(&alt_port->bridge, connector_status_disconnected);
> +
> + pmic_glink_altmode_request(altmode, ALTMODE_PAN_ACK, alt_port->index);
> +};
> +
> +static enum typec_orientation pmic_glink_altmode_orientation(unsigned int orientation)
> +{
> + if (orientation == 0)
> + return TYPEC_ORIENTATION_NORMAL;
> + else if (orientation == 1)
> + return TYPEC_ORIENTATION_REVERSE;
> + else
> + return TYPEC_ORIENTATION_NONE;
> +}
> +
> +#define SC8180X_PORT_MASK 0x000000ff
> +#define SC8180X_ORIENTATION_MASK 0x0000ff00
> +#define SC8180X_MUX_MASK 0x00ff0000
> +#define SC8180X_MODE_MASK 0x3f000000
> +#define SC8180X_HPD_STATE_MASK 0x40000000
> +#define SC8180X_HPD_IRQ_MASK 0x80000000
> +
> +static void pmic_glink_altmode_sc8180xp_notify(struct pmic_glink_altmode *altmode,
> + const void *data, size_t len)
> +{
> + struct pmic_glink_altmode_port *alt_port;
> + const struct usbc_sc8180x_notify *msg;
> + u32 notification;
> + u8 orientation;
> + u8 hpd_state;
> + u8 hpd_irq;
> + u16 svid;
> + u8 port;
> + u8 mode;
> + u8 mux;
> +
> + if (len != sizeof(*msg)) {
> + dev_warn(altmode->dev, "invalid length of USBC_NOTIFY indication: %zd\n", len);
> + return;
> + }
> +
> + msg = data;
> + notification = le32_to_cpu(msg->notification);
> + port = FIELD_GET(SC8180X_PORT_MASK, notification);
> + orientation = FIELD_GET(SC8180X_ORIENTATION_MASK, notification);
> + mux = FIELD_GET(SC8180X_MUX_MASK, notification);
> + mode = FIELD_GET(SC8180X_MODE_MASK, notification);
> + hpd_state = FIELD_GET(SC8180X_HPD_STATE_MASK, notification);
> + hpd_irq = FIELD_GET(SC8180X_HPD_IRQ_MASK, notification);
> +
The kernel test robot keeps complaining about these FIELD_GET because
there is no #include <linux/bitfield.h>
> + svid = mux == 2 ? USB_TYPEC_DP_SID : 0;
> +
> + if (!altmode->ports[port].altmode) {
> + dev_dbg(altmode->dev, "notification on undefined port %d\n", port);
> + return;
> + }
> +
> + alt_port = &altmode->ports[port];
> + alt_port->orientation = pmic_glink_altmode_orientation(orientation);
> + alt_port->svid = mux == 2 ? USB_TYPEC_DP_SID : 0;
> + alt_port->mode = mode;
> + alt_port->hpd_state = hpd_state;
> + alt_port->hpd_irq = hpd_irq;
> + schedule_work(&alt_port->work);
> +}
> +
> +#define SC8280XP_DPAM_MASK 0x3f
> +#define SC8280XP_HPD_STATE_MASK BIT(6)
> +#define SC8280XP_HPD_IRQ_MASK BIT(7)
> +
> +static void pmic_glink_altmode_sc8280xp_notify(struct pmic_glink_altmode *altmode,
> + u16 svid, const void *data, size_t len)
> +{
> + struct pmic_glink_altmode_port *alt_port;
> + const struct usbc_notify *notify;
> + u8 orientation;
> + u8 hpd_state;
> + u8 hpd_irq;
> + u8 mode;
> + u8 port;
> +
> + if (len != sizeof(*notify)) {
> + dev_warn(altmode->dev, "invalid length USBC_NOTIFY_IND: %zd\n",
> + len);
> + return;
> + }
> +
> + notify = data;
> +
> + port = notify->payload[0];
> + orientation = notify->payload[1];
> + mode = FIELD_GET(SC8280XP_DPAM_MASK, notify->payload[8]) - DPAM_HPD_A;
> + hpd_state = FIELD_GET(SC8280XP_HPD_STATE_MASK, notify->payload[8]);
> + hpd_irq = FIELD_GET(SC8280XP_HPD_IRQ_MASK, notify->payload[8]);
> +
> + if (!altmode->ports[port].altmode) {
> + dev_dbg(altmode->dev, "notification on undefined port %d\n", port);
> + return;
> + }
> +
> + alt_port = &altmode->ports[port];
> + alt_port->orientation = pmic_glink_altmode_orientation(orientation);
> + alt_port->svid = svid;
> + alt_port->mode = mode;
> + alt_port->hpd_state = hpd_state;
> + alt_port->hpd_irq = hpd_irq;
> + schedule_work(&alt_port->work);
> +}
> +
> +static void pmic_glink_altmode_callback(const void *data, size_t len, void *priv)
> +{
> + struct pmic_glink_altmode *altmode = priv;
> + const struct pmic_glink_hdr *hdr = data;
> + u16 opcode;
> + u16 svid;
> +
> + opcode = le32_to_cpu(hdr->opcode) & 0xff;
> + svid = le32_to_cpu(hdr->opcode) >> 16;
> +
> + switch (opcode) {
> + case USBC_CMD_WRITE_REQ:
> + complete(&altmode->pan_ack);
> + break;
> + case USBC_NOTIFY_IND:
> + pmic_glink_altmode_sc8280xp_notify(altmode, svid, data, len);
> + break;
> + case USBC_SC8180X_NOTIFY_IND:
> + pmic_glink_altmode_sc8180xp_notify(altmode, data, len);
> + break;
> + }
> +}
> +
> +static int pmic_glink_altmode_attach(struct drm_bridge *bridge,
> + enum drm_bridge_attach_flags flags)
> +{
> + return flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR ? 0 : -EINVAL;
> +}
> +
> +static const struct drm_bridge_funcs pmic_glink_altmode_bridge_funcs = {
> + .attach = pmic_glink_altmode_attach,
> +};
> +
> +static void pmic_glink_altmode_put_mux(void *data)
> +{
> + typec_mux_put(data);
> +}
> +
> +static void pmic_glink_altmode_put_switch(void *data)
> +{
> + typec_switch_put(data);
> +}
> +
> +static void pmic_glink_altmode_enable_worker(struct work_struct *work)
> +{
> + struct pmic_glink_altmode *altmode = work_to_altmode(work);
> + int ret;
> +
> + ret = pmic_glink_altmode_request(altmode, ALTMODE_PAN_EN, 0);
> + if (ret)
> + dev_err(altmode->dev, "failed to request altmode notifications\n");
> +}
> +
> +static void pmic_glink_altmode_pdr_notify(void *priv, int state)
> +{
> + struct pmic_glink_altmode *altmode = priv;
> +
> + if (state == SERVREG_SERVICE_STATE_UP)
> + schedule_work(&altmode->enable_work);
> +}
> +
> +static const struct of_device_id pmic_glink_altmode_of_quirks[] = {
> + { .compatible = "qcom,sc8180x-pmic-glink", .data = (void *)PMIC_GLINK_OWNER_USBC },
> + {}
> +};
> +
> +static int pmic_glink_altmode_probe(struct auxiliary_device *adev,
> + const struct auxiliary_device_id *id)
> +{
> + struct pmic_glink_altmode_port *alt_port;
> + struct pmic_glink_altmode *altmode;
> + struct typec_altmode_desc mux_desc = {};
> + const struct of_device_id *match;
> + struct fwnode_handle *fwnode;
> + struct device *dev = &adev->dev;
> + u32 port;
> + int ret;
> +
> + altmode = devm_kzalloc(dev, sizeof(*altmode), GFP_KERNEL);
> + if (!altmode)
> + return -ENOMEM;
> +
> + altmode->dev = dev;
> +
> + match = of_match_device(pmic_glink_altmode_of_quirks, dev->parent);
> + if (match)
> + altmode->owner_id = (unsigned long)match->data;
> + else
> + altmode->owner_id = PMIC_GLINK_OWNER_USBC_PAN;
> +
> + INIT_WORK(&altmode->enable_work, pmic_glink_altmode_enable_worker);
> + init_completion(&altmode->pan_ack);
> + mutex_init(&altmode->lock);
> +
> + device_for_each_child_node(dev, fwnode) {
> + ret = fwnode_property_read_u32(fwnode, "reg", &port);
> + if (ret < 0) {
> + dev_err(dev, "missing reg property of %pOFn\n", fwnode);
> + return ret;
> + }
> +
> + if (port >= ARRAY_SIZE(altmode->ports)) {
> + dev_warn(dev, "invalid connector number, ignoring\n");
> + continue;
> + }
> +
> + if (altmode->ports[port].altmode) {
> + dev_err(dev, "multiple connector definition for port %u\n", port);
> + return -EINVAL;
> + }
> +
> + alt_port = &altmode->ports[port];
> + alt_port->altmode = altmode;
> + alt_port->index = port;
> + INIT_WORK(&alt_port->work, pmic_glink_altmode_worker);
> +
> + alt_port->bridge.funcs = &pmic_glink_altmode_bridge_funcs;
> + alt_port->bridge.of_node = to_of_node(fwnode);
> + alt_port->bridge.ops = DRM_BRIDGE_OP_HPD;
> + alt_port->bridge.type = DRM_MODE_CONNECTOR_USB;
> +
> + ret = devm_drm_bridge_add(dev, &alt_port->bridge);
> + if (ret)
> + return ret;
> +
> + alt_port->dp_alt.svid = USB_TYPEC_DP_SID;
> + alt_port->dp_alt.mode = USB_TYPEC_DP_MODE;
> + alt_port->dp_alt.active = 1;
> +
> + mux_desc.svid = USB_TYPEC_DP_SID;
> + mux_desc.mode = USB_TYPEC_DP_MODE;
> + alt_port->typec_mux = fwnode_typec_mux_get(fwnode, &mux_desc);
> + if (IS_ERR(alt_port->typec_mux))
> + return dev_err_probe(dev, PTR_ERR(alt_port->typec_mux),
> + "failed to acquire mode-switch for port: %d\n",
> + port);
> +
> + ret = devm_add_action_or_reset(dev, pmic_glink_altmode_put_mux,
> + alt_port->typec_mux);
> + if (ret)
> + return ret;
> +
> + alt_port->typec_switch = fwnode_typec_switch_get(fwnode);
> + if (IS_ERR(alt_port->typec_switch))
> + return dev_err_probe(dev, PTR_ERR(alt_port->typec_switch),
> + "failed to acquire orientation-switch for port: %d\n",
> + port);
> +
> + ret = devm_add_action_or_reset(dev, pmic_glink_altmode_put_switch,
> + alt_port->typec_switch);
> + if (ret)
> + return ret;
> + }
> +
> + altmode->client = devm_pmic_glink_register_client(dev,
> + altmode->owner_id,
> + pmic_glink_altmode_callback,
> + pmic_glink_altmode_pdr_notify,
> + altmode);
> + return PTR_ERR_OR_ZERO(altmode->client);
> +}
> +
> +static const struct auxiliary_device_id pmic_glink_altmode_id_table[] = {
> + { .name = "pmic_glink.altmode", },
> + {},
> +};
> +MODULE_DEVICE_TABLE(auxiliary, pmic_glink_altmode_id_table);
> +
> +static struct auxiliary_driver pmic_glink_altmode_driver = {
> + .name = "pmic_glink_altmode",
> + .probe = pmic_glink_altmode_probe,
> + .id_table = pmic_glink_altmode_id_table,
> +};
> +
> +module_auxiliary_driver(pmic_glink_altmode_driver);
> +
> +MODULE_DESCRIPTION("Qualcomm PMIC GLINK Altmode driver");
> +MODULE_LICENSE("GPL");
> --
> 2.37.3
>
