Messages in this thread | | | Date | Fri, 20 Jan 2023 11:33:24 +0100 | Subject | Re: [PATCH v2 3/4] soc: qcom: pmic_glink: Introduce altmode support | From | Neil Armstrong <> |
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On 20/01/2023 11:06, Neil Armstrong wrote: > On 13/01/2023 05:11, Bjorn Andersson wrote: >> From: Bjorn Andersson <bjorn.andersson@linaro.org> >> >> 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@linaro.org> >> Signed-off-by: Bjorn Andersson <quic_bjorande@quicinc.com> >> --- >> >> 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); >> + >> + 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; > > In my testing, the design of a bridge in the altmode driver made all the probe very fragile, > meaning that any device that won't probe in the full usb--pmic-glink--display driver would > prevent the whole to actually probe. > > This is why drm_connector_oob_hotplug_event() was used in drivers/usb/typec/altmodes/displayport.c > and a similar design for cec where both attach to a device so there's no probe dependency. > > I think there's a possible simplification here by using : > of_drm_find_bridge() instead on the endpoint target to get the last bridge, > or we could probably use the same drm_connector_oob_hotplug_event() but in any way we should > add missing pieces in drm_bridge_connector and drm/msm/dp/dp_drm.c > > First in drm/msm/dp/dp_drm.c, the driver should add the of_node to the DP bridge so it can > be found from the dp controller node. > > Secondly, we could add a fwnode in drm_bridge like in drm_connector and in drm_bridge_connector_init() > we could set the connector fwnode to the last bridge fwnode + the connector oob event handler. > In this case the drm_connector_oob_hotplug_event() design should work. > > Anyway, I think the bindings is correct, so it's a matter of implementation to avoid delaying the > display driver probe until the pmic_glink probes entirely.
While looking closely, I don't think we can design differently except moving the bridge code into a dummy bridge into gpu/drm/bridge, but this won't solve anything but make things even more complex.
This design follows how generic display connector bridge is designed like in gpu/drm/bridge/display-connector.c so it's valid.
So for the DRM Bridge part: Acked-by: Neil Armstrong <neil.armstrong@linaro.org>
Neil
> > Neil > >> + >> + 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"); >
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