Re: [PATCH v1 2/6] mfd: cros_ec: Add MKBP event support
From: Gwendal Grignou
Date: Wed Feb 10 2016 - 12:41:50 EST
[Resend[We should not used kmalloc when get events, these functions
are called quite often.
Gwendal.
On Fri, Feb 5, 2016 at 5:32 AM, Tomeu Vizoso <tomeu.vizoso@xxxxxxxxxxxxx> wrote:
> From: Vic Yang <victoryang@xxxxxxxxxx>
>
> Newer revisions of the ChromeOS EC add more events besides the keyboard
> ones. So handle interrupts in the MFD driver and let consumers register
> for notifications for the events they might care.
>
> To keep backward compatibility, if the EC doesn't support MKBP event, we
> fall back to the old MKBP key matrix host command.
>
> Signed-off-by: Vic Yang <victoryang@xxxxxxxxxxxx>
> [bleung: fixup some context changes going from v3.14 to v3.18]
> Signed-off-by: Benson Leung <bleung@xxxxxxxxxxxx>
> [tomeu: adapted to changes in mainline (in power-supply and platform/chrome)]
> Signed-off-by: Tomeu Vizoso <tomeu.vizoso@xxxxxxxxxxxxx>
> Cc: Randall Spangler <rspangler@xxxxxxxxxxxx>
> Cc: Vincent Palatin <vpalatin@xxxxxxxxxxxx>
>
> ---
>
> drivers/input/keyboard/cros_ec_keyb.c | 135 ++++++++------------------------
> drivers/mfd/cros_ec.c | 57 +++++++++++++-
> drivers/platform/chrome/cros_ec_proto.c | 102 ++++++++++++++++++++++++
> include/linux/mfd/cros_ec.h | 44 +++++++++++
> include/linux/mfd/cros_ec_commands.h | 34 ++++++++
> 5 files changed, 265 insertions(+), 107 deletions(-)
>
> diff --git a/drivers/input/keyboard/cros_ec_keyb.c b/drivers/input/keyboard/cros_ec_keyb.c
> index b01966dc7eb3..b891503143dc 100644
> --- a/drivers/input/keyboard/cros_ec_keyb.c
> +++ b/drivers/input/keyboard/cros_ec_keyb.c
> @@ -27,6 +27,7 @@
> #include <linux/input.h>
> #include <linux/interrupt.h>
> #include <linux/kernel.h>
> +#include <linux/notifier.h>
> #include <linux/platform_device.h>
> #include <linux/slab.h>
> #include <linux/input/matrix_keypad.h>
> @@ -44,6 +45,7 @@
> * @dev: Device pointer
> * @idev: Input device
> * @ec: Top level ChromeOS device to use to talk to EC
> + * @notifier: interrupt event notifier for transport devices
> */
> struct cros_ec_keyb {
> unsigned int rows;
> @@ -57,6 +59,7 @@ struct cros_ec_keyb {
> struct device *dev;
> struct input_dev *idev;
> struct cros_ec_device *ec;
> + struct notifier_block notifier;
> };
>
>
> @@ -146,67 +149,44 @@ static void cros_ec_keyb_process(struct cros_ec_keyb *ckdev,
> input_sync(ckdev->idev);
> }
>
> -static int cros_ec_keyb_get_state(struct cros_ec_keyb *ckdev, uint8_t *kb_state)
> -{
> - int ret = 0;
> - struct cros_ec_command *msg;
> -
> - msg = kmalloc(sizeof(*msg) + ckdev->cols, GFP_KERNEL);
> - if (!msg)
> - return -ENOMEM;
> -
> - msg->version = 0;
> - msg->command = EC_CMD_MKBP_STATE;
> - msg->insize = ckdev->cols;
> - msg->outsize = 0;
> -
> - ret = cros_ec_cmd_xfer(ckdev->ec, msg);
> - if (ret < 0) {
> - dev_err(ckdev->dev, "Error transferring EC message %d\n", ret);
> - goto exit;
> - }
> -
> - memcpy(kb_state, msg->data, ckdev->cols);
> -exit:
> - kfree(msg);
> - return ret;
> -}
> -
> -static irqreturn_t cros_ec_keyb_irq(int irq, void *data)
> +static int cros_ec_keyb_open(struct input_dev *dev)
> {
> - struct cros_ec_keyb *ckdev = data;
> - struct cros_ec_device *ec = ckdev->ec;
> - int ret;
> - uint8_t kb_state[ckdev->cols];
> -
> - if (device_may_wakeup(ec->dev))
> - pm_wakeup_event(ec->dev, 0);
> -
> - ret = cros_ec_keyb_get_state(ckdev, kb_state);
> - if (ret >= 0)
> - cros_ec_keyb_process(ckdev, kb_state, ret);
> - else
> - dev_err(ec->dev, "failed to get keyboard state: %d\n", ret);
> + struct cros_ec_keyb *ckdev = input_get_drvdata(dev);
>
> - return IRQ_HANDLED;
> + return blocking_notifier_chain_register(&ckdev->ec->event_notifier,
> + &ckdev->notifier);
> }
>
> -static int cros_ec_keyb_open(struct input_dev *dev)
> +static void cros_ec_keyb_close(struct input_dev *dev)
> {
> struct cros_ec_keyb *ckdev = input_get_drvdata(dev);
> - struct cros_ec_device *ec = ckdev->ec;
>
> - return request_threaded_irq(ec->irq, NULL, cros_ec_keyb_irq,
> - IRQF_TRIGGER_LOW | IRQF_ONESHOT,
> - "cros_ec_keyb", ckdev);
> + blocking_notifier_chain_unregister(&ckdev->ec->event_notifier,
> + &ckdev->notifier);
> }
>
> -static void cros_ec_keyb_close(struct input_dev *dev)
> +static int cros_ec_keyb_work(struct notifier_block *nb,
> + unsigned long queued_during_suspend, void *_notify)
> {
> - struct cros_ec_keyb *ckdev = input_get_drvdata(dev);
> - struct cros_ec_device *ec = ckdev->ec;
> + struct cros_ec_keyb *ckdev = container_of(nb, struct cros_ec_keyb,
> + notifier);
>
> - free_irq(ec->irq, ckdev);
> + if (ckdev->ec->event_data.event_type != EC_MKBP_EVENT_KEY_MATRIX)
> + return NOTIFY_DONE;
> + /*
> + * If EC is not the wake source, discard key state changes during
> + * suspend.
> + */
> + if (queued_during_suspend)
> + return NOTIFY_OK;
> + if (ckdev->ec->event_size != ckdev->cols) {
> + dev_err(ckdev->dev,
> + "Discarded incomplete key matrix event.\n");
> + return NOTIFY_OK;
> + }
> + cros_ec_keyb_process(ckdev, ckdev->ec->event_data.data.key_matrix,
> + ckdev->ec->event_size);
> + return NOTIFY_OK;
> }
>
> /*
> @@ -266,12 +246,8 @@ static int cros_ec_keyb_probe(struct platform_device *pdev)
> if (!idev)
> return -ENOMEM;
>
> - if (!ec->irq) {
> - dev_err(dev, "no EC IRQ specified\n");
> - return -EINVAL;
> - }
> -
> ckdev->ec = ec;
> + ckdev->notifier.notifier_call = cros_ec_keyb_work;
> ckdev->dev = dev;
> dev_set_drvdata(&pdev->dev, ckdev);
>
> @@ -312,54 +288,6 @@ static int cros_ec_keyb_probe(struct platform_device *pdev)
> return 0;
> }
>
> -#ifdef CONFIG_PM_SLEEP
> -/* Clear any keys in the buffer */
> -static void cros_ec_keyb_clear_keyboard(struct cros_ec_keyb *ckdev)
> -{
> - uint8_t old_state[ckdev->cols];
> - uint8_t new_state[ckdev->cols];
> - unsigned long duration;
> - int i, ret;
> -
> - /*
> - * Keep reading until we see that the scan state does not change.
> - * That indicates that we are done.
> - *
> - * Assume that the EC keyscan buffer is at most 32 deep.
> - */
> - duration = jiffies;
> - ret = cros_ec_keyb_get_state(ckdev, new_state);
> - for (i = 1; !ret && i < 32; i++) {
> - memcpy(old_state, new_state, sizeof(old_state));
> - ret = cros_ec_keyb_get_state(ckdev, new_state);
> - if (0 == memcmp(old_state, new_state, sizeof(old_state)))
> - break;
> - }
> - duration = jiffies - duration;
> - dev_info(ckdev->dev, "Discarded %d keyscan(s) in %dus\n", i,
> - jiffies_to_usecs(duration));
> -}
> -
> -static int cros_ec_keyb_resume(struct device *dev)
> -{
> - struct cros_ec_keyb *ckdev = dev_get_drvdata(dev);
> -
> - /*
> - * When the EC is not a wake source, then it could not have caused the
> - * resume, so we clear the EC's key scan buffer. If the EC was a
> - * wake source (e.g. the lid is open and the user might press a key to
> - * wake) then the key scan buffer should be preserved.
> - */
> - if (!ckdev->ec->was_wake_device)
> - cros_ec_keyb_clear_keyboard(ckdev);
> -
> - return 0;
> -}
> -
> -#endif
> -
> -static SIMPLE_DEV_PM_OPS(cros_ec_keyb_pm_ops, NULL, cros_ec_keyb_resume);
> -
> #ifdef CONFIG_OF
> static const struct of_device_id cros_ec_keyb_of_match[] = {
> { .compatible = "google,cros-ec-keyb" },
> @@ -373,7 +301,6 @@ static struct platform_driver cros_ec_keyb_driver = {
> .driver = {
> .name = "cros-ec-keyb",
> .of_match_table = of_match_ptr(cros_ec_keyb_of_match),
> - .pm = &cros_ec_keyb_pm_ops,
> },
> };
>
> diff --git a/drivers/mfd/cros_ec.c b/drivers/mfd/cros_ec.c
> index 0eee63542038..fbe78b819fdd 100644
> --- a/drivers/mfd/cros_ec.c
> +++ b/drivers/mfd/cros_ec.c
> @@ -23,6 +23,7 @@
> #include <linux/module.h>
> #include <linux/mfd/core.h>
> #include <linux/mfd/cros_ec.h>
> +#include <asm/unaligned.h>
>
> #define CROS_EC_DEV_EC_INDEX 0
> #define CROS_EC_DEV_PD_INDEX 1
> @@ -49,11 +50,28 @@ static const struct mfd_cell ec_pd_cell = {
> .pdata_size = sizeof(pd_p),
> };
>
> +static irqreturn_t ec_irq_thread(int irq, void *data)
> +{
> + struct cros_ec_device *ec_dev = data;
> + int ret;
> +
> + if (device_may_wakeup(ec_dev->dev))
> + pm_wakeup_event(ec_dev->dev, 0);
> +
> + ret = cros_ec_get_next_event(ec_dev);
> + if (ret > 0)
> + blocking_notifier_call_chain(&ec_dev->event_notifier,
> + 0, ec_dev);
> + return IRQ_HANDLED;
> +}
> +
> int cros_ec_register(struct cros_ec_device *ec_dev)
> {
> struct device *dev = ec_dev->dev;
> int err = 0;
>
> + BLOCKING_INIT_NOTIFIER_HEAD(&ec_dev->event_notifier);
> +
> ec_dev->max_request = sizeof(struct ec_params_hello);
> ec_dev->max_response = sizeof(struct ec_response_get_protocol_info);
> ec_dev->max_passthru = 0;
> @@ -70,13 +88,24 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
>
> cros_ec_query_all(ec_dev);
>
> + if (ec_dev->irq) {
> + err = request_threaded_irq(ec_dev->irq, NULL, ec_irq_thread,
> + IRQF_TRIGGER_LOW | IRQF_ONESHOT,
> + "chromeos-ec", ec_dev);
> + if (err) {
> + dev_err(dev, "request irq %d: error %d\n",
> + ec_dev->irq, err);
> + return err;
> + }
> + }
> +
> err = mfd_add_devices(ec_dev->dev, PLATFORM_DEVID_AUTO, &ec_cell, 1,
> NULL, ec_dev->irq, NULL);
> if (err) {
> dev_err(dev,
> "Failed to register Embedded Controller subdevice %d\n",
> err);
> - return err;
> + goto fail_mfd;
> }
>
> if (ec_dev->max_passthru) {
> @@ -94,7 +123,7 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
> dev_err(dev,
> "Failed to register Power Delivery subdevice %d\n",
> err);
> - return err;
> + goto fail_mfd;
> }
> }
>
> @@ -103,13 +132,18 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
> if (err) {
> mfd_remove_devices(dev);
> dev_err(dev, "Failed to register sub-devices\n");
> - return err;
> + goto fail_mfd;
> }
> }
>
> dev_info(dev, "Chrome EC device registered\n");
>
> return 0;
> +
> +fail_mfd:
> + if (ec_dev->irq)
> + free_irq(ec_dev->irq, ec_dev);
> + return err;
> }
> EXPORT_SYMBOL(cros_ec_register);
>
> @@ -136,13 +170,30 @@ int cros_ec_suspend(struct cros_ec_device *ec_dev)
> }
> EXPORT_SYMBOL(cros_ec_suspend);
>
> +static void cros_ec_drain_events(struct cros_ec_device *ec_dev)
> +{
> + while (cros_ec_get_next_event(ec_dev) > 0)
> + blocking_notifier_call_chain(&ec_dev->event_notifier,
> + 1, ec_dev);
> +}
> +
> int cros_ec_resume(struct cros_ec_device *ec_dev)
> {
> enable_irq(ec_dev->irq);
>
> + /*
> + * In some case, we need to distinguish events that occur during
> + * suspend if the EC is not a wake source. For example, keypresses
> + * during suspend should be discarded if it does not wake the system.
> + *
> + * If the EC is not a wake source, drain the event queue and mark them
> + * as "queued during suspend".
> + */
> if (ec_dev->wake_enabled) {
> disable_irq_wake(ec_dev->irq);
> ec_dev->wake_enabled = 0;
> + } else {
> + cros_ec_drain_events(ec_dev);
> }
>
> return 0;
> diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
> index 990308ca384f..6e138e2333f3 100644
> --- a/drivers/platform/chrome/cros_ec_proto.c
> +++ b/drivers/platform/chrome/cros_ec_proto.c
> @@ -19,6 +19,7 @@
> #include <linux/device.h>
> #include <linux/module.h>
> #include <linux/slab.h>
> +#include <asm/unaligned.h>
>
> #define EC_COMMAND_RETRIES 50
>
> @@ -234,11 +235,44 @@ static int cros_ec_host_command_proto_query_v2(struct cros_ec_device *ec_dev)
> return ret;
> }
>
> +static int cros_ec_get_host_command_version_mask(struct cros_ec_device *ec_dev,
> + u16 cmd, u32 *mask)
> +{
> + struct ec_params_get_cmd_versions *pver;
> + struct ec_response_get_cmd_versions *rver;
> + struct cros_ec_command *msg;
> + int ret;
> +
> + msg = kmalloc(sizeof(*msg) + max(sizeof(rver), sizeof(pver)),
> + GFP_KERNEL);
Victor's version in https://chromium-review.googlesource.com/272954
looks cleaner: no malloc, no need to cast rver.
> + if (!msg)
> + return -ENOMEM;
> +
> + msg->version = 0;
> + msg->command = EC_CMD_GET_CMD_VERSIONS;
> + msg->insize = sizeof(rver);
> + msg->outsize = sizeof(pver);
> +
> + pver = (struct ec_params_get_cmd_versions *)msg->data;
> + pver->cmd = cmd;
> +
> + ret = cros_ec_cmd_xfer(ec_dev, msg);
> + if (ret > 0) {
> + rver = (struct ec_response_get_cmd_versions *)msg->data;
> + *mask = rver->version_mask;
> + }
> +
> + kfree(msg);
> +
> + return ret;
> +}
> +
> int cros_ec_query_all(struct cros_ec_device *ec_dev)
> {
> struct device *dev = ec_dev->dev;
> struct cros_ec_command *proto_msg;
> struct ec_response_get_protocol_info *proto_info;
> + u32 ver_mask = 0;
> int ret;
>
> proto_msg = kzalloc(sizeof(*proto_msg) + sizeof(*proto_info),
> @@ -328,6 +362,15 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev)
> goto exit;
> }
>
> + /* Probe if MKBP event is supported */
> + ret = cros_ec_get_host_command_version_mask(ec_dev,
> + EC_CMD_GET_NEXT_EVENT,
> + &ver_mask);
> + if (ret < 0 || ver_mask == 0)
> + ec_dev->mkbp_event_supported = 0;
> + else
> + ec_dev->mkbp_event_supported = 1;
> +
> exit:
> kfree(proto_msg);
> return ret;
> @@ -380,3 +423,62 @@ int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev,
> return ret;
> }
> EXPORT_SYMBOL(cros_ec_cmd_xfer);
> +
> +static int get_next_event(struct cros_ec_device *ec_dev)
> +{
> + struct cros_ec_command *msg;
> + int ret;
> +
> + msg = kmalloc(sizeof(*msg) + sizeof(ec_dev->event_data), GFP_KERNEL);
Same grip about malloc(). This function will be called very often when
sensors are used.
> + if (!msg)
> + return -ENOMEM;
> +
> + msg->version = 0;
> + msg->command = EC_CMD_GET_NEXT_EVENT;
> + msg->insize = sizeof(ec_dev->event_data);
> + msg->outsize = 0;
> +
> + ret = cros_ec_cmd_xfer(ec_dev, msg);
> + if (ret > 0) {
> + ec_dev->event_size = ret - 1;
> + memcpy(&ec_dev->event_data, msg->data,
> + sizeof(ec_dev->event_data));
> + }
> +
> + kfree(msg);
> +
> + return ret;
> +}
> +
> +static int get_keyboard_state_event(struct cros_ec_device *ec_dev)
> +{
> + struct cros_ec_command *msg;
> +
> + msg = kmalloc(sizeof(*msg) + sizeof(ec_dev->event_data.data),
Given this command will be used on every key press, it is better to
pre-allocate data (like in
https://chromium-review.googlesource.com/276768) and use msg on the
stack like Victor's changes.
> + GFP_KERNEL);
> + if (!msg)
> + return -ENOMEM;
> +
> + msg->version = 0;
> + msg->command = EC_CMD_MKBP_STATE;
> + msg->insize = sizeof(ec_dev->event_data.data);
> + msg->outsize = 0;
> +
> + ec_dev->event_size = cros_ec_cmd_xfer(ec_dev, msg);
> + ec_dev->event_data.event_type = EC_MKBP_EVENT_KEY_MATRIX;
> + memcpy(&ec_dev->event_data.data, msg->data,
> + sizeof(ec_dev->event_data.data));
> +
> + kfree(msg);
> +
> + return ec_dev->event_size;
> +}
> +
> +int cros_ec_get_next_event(struct cros_ec_device *ec_dev)
> +{
> + if (ec_dev->mkbp_event_supported)
> + return get_next_event(ec_dev);
> + else
> + return get_keyboard_state_event(ec_dev);
> +}
> +EXPORT_SYMBOL(cros_ec_get_next_event);
> diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
> index a677c2bd485c..8a8fa75178c6 100644
> --- a/include/linux/mfd/cros_ec.h
> +++ b/include/linux/mfd/cros_ec.h
> @@ -72,6 +72,24 @@ struct cros_ec_command {
> uint8_t data[0];
> };
>
> +/*
> + * event_data is used by keyboard or event notifier:
> + * event_data format:
> + * If MKBP protocol is supported:
> + * 0 1
> + * +-----------+--------------------------------
> + * | type | payload
> + * +-----------+--------------------------------
> + * |HOST_EVENT | EVENT (32 bit)
> + * |KEY_MATRIX | Keyboard keys pressed.
> + * |SENSOR_FIFO| Sensors FIFO information.
> + *
> + * Otherwise:
> + * 0 1
> + * +-----------+--------------------------------
> + * |Unused | Keyboard keys pressed.
> + */
> +
> /**
> * struct cros_ec_device - Information about a ChromeOS EC device
> *
> @@ -107,6 +125,9 @@ struct cros_ec_command {
> * should check msg.result for the EC's result code.
> * @pkt_xfer: send packet to EC and get response
> * @lock: one transaction at a time
> + * @event_notifier: interrupt event notifier for transport devices.
> + * @event_data: raw payload transferred with the MKBP event.
> + * @event_size: size in bytes of the event data.
> */
> struct cros_ec_device {
>
> @@ -135,6 +156,11 @@ struct cros_ec_device {
> int (*pkt_xfer)(struct cros_ec_device *ec,
> struct cros_ec_command *msg);
> struct mutex lock;
> + bool mkbp_event_supported;
> + struct blocking_notifier_head event_notifier;
> +
> + struct ec_response_get_next_event event_data;
> + int event_size;
> };
>
> /* struct cros_ec_platform - ChromeOS EC platform information
> @@ -252,9 +278,27 @@ int cros_ec_register(struct cros_ec_device *ec_dev);
> */
> int cros_ec_query_all(struct cros_ec_device *ec_dev);
>
> +/**
> + * cros_ec_get_next_event - Fetch next event from the ChromeOS EC
> + *
> + * @ec_dev: Device to fetch event from
> + * @return 0 if ok, -ve on error
> + */
> +int cros_ec_get_next_event(struct cros_ec_device *ec_dev);
> +
> /* sysfs stuff */
> extern struct attribute_group cros_ec_attr_group;
> extern struct attribute_group cros_ec_lightbar_attr_group;
> extern struct attribute_group cros_ec_vbc_attr_group;
>
> +/**
> + * cros_ec_get_host_event - Return a mask of event set by the EC.
> + *
> + * When MKBP is supported, when the EC raises an interrupt,
> + * We collect the events raised and call the functions in the ec notifier.
> + *
> + * This function is a helper to know which events are raised.
> + */
> +uint32_t cros_ec_get_host_event(struct cros_ec_device *ec_dev);
> +
> #endif /* __LINUX_MFD_CROS_EC_H */
> diff --git a/include/linux/mfd/cros_ec_commands.h b/include/linux/mfd/cros_ec_commands.h
> index 13b630c10d4c..d86526f0bd8e 100644
> --- a/include/linux/mfd/cros_ec_commands.h
> +++ b/include/linux/mfd/cros_ec_commands.h
> @@ -1762,6 +1762,40 @@ struct ec_result_keyscan_seq_ctrl {
> };
> } __packed;
>
> +/*
> + * Get the next pending MKBP event.
> + *
> + * Returns EC_RES_UNAVAILABLE if there is no event pending.
> + */
> +#define EC_CMD_GET_NEXT_EVENT 0x67
> +
> +enum ec_mkbp_event {
> + /* Keyboard matrix changed. The event data is the new matrix state. */
> + EC_MKBP_EVENT_KEY_MATRIX = 0,
> +
> + /* New host event. The event data is 4 bytes of host event flags. */
> + EC_MKBP_EVENT_HOST_EVENT = 1,
> +
> + /* New Sensor FIFO data. The event data is fifo_info structure. */
> + EC_MKBP_EVENT_SENSOR_FIFO = 2,
> +
> + /* Number of MKBP events */
> + EC_MKBP_EVENT_COUNT,
> +};
> +
> +union ec_response_get_next_data {
> + uint8_t key_matrix[13];
> +
> + /* Unaligned */
> + uint32_t host_event;
> +} __packed;
> +
> +struct ec_response_get_next_event {
> + uint8_t event_type;
> + /* Followed by event data if any */
> + union ec_response_get_next_data data;
> +} __packed;
> +
> /*****************************************************************************/
> /* Temperature sensor commands */
>
> --
> 2.5.0
>