Hi Dmitry,
Thanks for the review!
On Mon, Sep 14, 2020 at 02:09:41PM -0700, Dmitry Torokhov wrote:
> Hi Cristian,
>
> On Sat, Aug 22, 2020 at 01:19:51AM +0300, Cristian Ciocaltea wrote:
> > The Actions Semi ATC260x PMICs are able to manage an onkey button.
> > This driver exposes the ATC260x onkey as an input device. It can also
> > be configured to force a system reset on a long key-press with an
> > adjustable duration.
> >
> > The currently supported chip variants are ATC2603C and ATC2609A.
> >
> > Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@xxxxxxxxx>
> > ---
> > drivers/input/misc/Kconfig | 11 ++
> > drivers/input/misc/Makefile | 2 +-
> > drivers/input/misc/atc260x-onkey.c | 304 +++++++++++++++++++++++++++++
> > 3 files changed, 316 insertions(+), 1 deletion(-)
> > create mode 100644 drivers/input/misc/atc260x-onkey.c
> >
> > diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig
> > index 362e8a01980c..9e297ebdea57 100644
> > --- a/drivers/input/misc/Kconfig
> > +++ b/drivers/input/misc/Kconfig
> > @@ -83,6 +83,17 @@ config INPUT_ARIZONA_HAPTICS
> > To compile this driver as a module, choose M here: the
> > module will be called arizona-haptics.
> >
> > +config INPUT_ATC260X_ONKEY
> > + tristate "Actions Semi ATC260x PMIC ONKEY"
> > + depends on MFD_ATC260X
> > + help
> > + Support the ONKEY of ATC260x PMICs as an input device reporting
> > + power button status. ONKEY can be used to wakeup from low power
> > + modes and force a reset on long press.
> > +
> > + To compile this driver as a module, choose M here: the
> > + module will be called atc260x-onkey.
> > +
> > config INPUT_ATMEL_CAPTOUCH
> > tristate "Atmel Capacitive Touch Button Driver"
> > depends on OF || COMPILE_TEST
> > diff --git a/drivers/input/misc/Makefile b/drivers/input/misc/Makefile
> > index a48e5f2d859d..7f854c6ecefa 100644
> > --- a/drivers/input/misc/Makefile
> > +++ b/drivers/input/misc/Makefile
> > @@ -16,6 +16,7 @@ obj-$(CONFIG_INPUT_ADXL34X_I2C) += adxl34x-i2c.o
> > obj-$(CONFIG_INPUT_ADXL34X_SPI) += adxl34x-spi.o
> > obj-$(CONFIG_INPUT_APANEL) += apanel.o
> > obj-$(CONFIG_INPUT_ARIZONA_HAPTICS) += arizona-haptics.o
> > +obj-$(CONFIG_INPUT_ATC260X_ONKEY) += atc260x-onkey.o
> > obj-$(CONFIG_INPUT_ATI_REMOTE2) += ati_remote2.o
> > obj-$(CONFIG_INPUT_ATLAS_BTNS) += atlas_btns.o
> > obj-$(CONFIG_INPUT_ATMEL_CAPTOUCH) += atmel_captouch.o
> > @@ -84,4 +85,3 @@ obj-$(CONFIG_INPUT_WM831X_ON) += wm831x-on.o
> > obj-$(CONFIG_INPUT_XEN_KBDDEV_FRONTEND) += xen-kbdfront.o
> > obj-$(CONFIG_INPUT_YEALINK) += yealink.o
> > obj-$(CONFIG_INPUT_IDEAPAD_SLIDEBAR) += ideapad_slidebar.o
> > -
> > diff --git a/drivers/input/misc/atc260x-onkey.c b/drivers/input/misc/atc260x-onkey.c
> > new file mode 100644
> > index 000000000000..7caec7d6f9ac
> > --- /dev/null
> > +++ b/drivers/input/misc/atc260x-onkey.c
> > @@ -0,0 +1,304 @@
> > +// SPDX-License-Identifier: GPL-2.0+
> > +/*
> > + * Onkey driver for Actions Semi ATC260x PMICs.
> > + *
> > + * Copyright (c) 2020 Cristian Ciocaltea <cristian.ciocaltea@xxxxxxxxx>
> > + */
> > +
> > +#include <linux/bitfield.h>
> > +#include <linux/input.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/mfd/atc260x/core.h>
> > +#include <linux/module.h>
> > +#include <linux/of.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/regmap.h>
> > +
> > +/* <2s for short press, >2s for long press */
> > +#define KEY_PRESS_TIME_SEC 2
> > +
> > +/* Driver internals */
> > +enum atc260x_onkey_reset_status {
> > + KEY_RESET_HW_DEFAULT,
> > + KEY_RESET_DISABLED,
> > + KEY_RESET_USER_SEL,
> > +};
> > +
> > +struct atc260x_onkey_params {
> > + u32 reg_int_ctl;
> > + u32 kdwn_state_bm;
> > + u32 long_int_pnd_bm;
> > + u32 short_int_pnd_bm;
> > + u32 kdwn_int_pnd_bm;
> > + u32 press_int_en_bm;
> > + u32 kdwn_int_en_bm;
> > + u32 press_time_bm;
> > + u32 reset_en_bm;
> > + u32 reset_time_bm;
> > +};
> > +
> > +struct atc260x_onkey {
> > + struct atc260x *atc260x;
> > + const struct atc260x_onkey_params *params;
> > + struct input_dev *input_dev;
> > + struct delayed_work work;
> > +};
> > +
> > +static const struct atc260x_onkey_params atc2603c_onkey_params = {
> > + .reg_int_ctl = ATC2603C_PMU_SYS_CTL2,
> > + .long_int_pnd_bm = ATC2603C_PMU_SYS_CTL2_ONOFF_LONG_PRESS,
> > + .short_int_pnd_bm = ATC2603C_PMU_SYS_CTL2_ONOFF_SHORT_PRESS,
> > + .kdwn_int_pnd_bm = ATC2603C_PMU_SYS_CTL2_ONOFF_PRESS_PD,
> > + .press_int_en_bm = ATC2603C_PMU_SYS_CTL2_ONOFF_INT_EN,
> > + .kdwn_int_en_bm = ATC2603C_PMU_SYS_CTL2_ONOFF_PRESS_INT_EN,
> > + .kdwn_state_bm = ATC2603C_PMU_SYS_CTL2_ONOFF_PRESS,
> > + .press_time_bm = ATC2603C_PMU_SYS_CTL2_ONOFF_PRESS_TIME,
> > + .reset_en_bm = ATC2603C_PMU_SYS_CTL2_ONOFF_PRESS_RESET_EN,
> > + .reset_time_bm = ATC2603C_PMU_SYS_CTL2_ONOFF_RESET_TIME_SEL,
> > +};
> > +
> > +static const struct atc260x_onkey_params atc2609a_onkey_params = {
> > + .reg_int_ctl = ATC2609A_PMU_SYS_CTL2,
> > + .long_int_pnd_bm = ATC2609A_PMU_SYS_CTL2_ONOFF_LONG_PRESS,
> > + .short_int_pnd_bm = ATC2609A_PMU_SYS_CTL2_ONOFF_SHORT_PRESS,
> > + .kdwn_int_pnd_bm = ATC2609A_PMU_SYS_CTL2_ONOFF_PRESS_PD,
> > + .press_int_en_bm = ATC2609A_PMU_SYS_CTL2_ONOFF_LSP_INT_EN,
> > + .kdwn_int_en_bm = ATC2609A_PMU_SYS_CTL2_ONOFF_PRESS_INT_EN,
> > + .kdwn_state_bm = ATC2609A_PMU_SYS_CTL2_ONOFF_PRESS,
> > + .press_time_bm = ATC2609A_PMU_SYS_CTL2_ONOFF_PRESS_TIME,
> > + .reset_en_bm = ATC2609A_PMU_SYS_CTL2_ONOFF_RESET_EN,
> > + .reset_time_bm = ATC2609A_PMU_SYS_CTL2_ONOFF_RESET_TIME_SEL,
> > +};
> > +
> > +static int atc2603x_onkey_hw_init(struct atc260x_onkey *onkey,
> > + enum atc260x_onkey_reset_status reset_status,
> > + u32 reset_time, u32 press_time)
> > +{
> > + u32 reg_bm, reg_val;
> > +
> > + reg_bm = onkey->params->long_int_pnd_bm |
> > + onkey->params->short_int_pnd_bm |
> > + onkey->params->kdwn_int_pnd_bm |
> > + onkey->params->press_int_en_bm |
> > + onkey->params->kdwn_int_en_bm;
> > +
> > + reg_val = reg_bm | press_time;
> > + reg_bm |= onkey->params->press_time_bm;
> > +
> > + if (reset_status == KEY_RESET_DISABLED) {
> > + reg_bm |= onkey->params->reset_en_bm;
> > + } else if (reset_status == KEY_RESET_USER_SEL) {
> > + reg_bm |= onkey->params->reset_en_bm |
> > + onkey->params->reset_time_bm;
> > + reg_val |= onkey->params->reset_en_bm | reset_time;
> > + }
> > +
> > + return regmap_update_bits(onkey->atc260x->regmap,
> > + onkey->params->reg_int_ctl, reg_bm, reg_val);
> > +}
> > +
> > +static void atc260x_onkey_query(struct atc260x_onkey *onkey)
> > +{
> > + u32 reg_bits;
> > + int ret, key_down;
> > +
> > + ret = regmap_read(onkey->atc260x->regmap,
> > + onkey->params->reg_int_ctl, &key_down);
> > + if (ret) {
> > + key_down = 1;
> > + dev_err(onkey->atc260x->dev,
> > + "Failed to read onkey status: %d\n", ret);
> > + } else {
> > + key_down &= onkey->params->kdwn_state_bm;
> > + }
> > +
> > + /*
> > + * The hardware generates interrupt only when the onkey pin is
> > + * asserted. Hence, the deassertion of the pin is simulated through
> > + * work queue.
> > + */
> > + if (key_down) {
> > + schedule_delayed_work(&onkey->work, msecs_to_jiffies(200));
> > + return;
> > + }
> > +
> > + /*
> > + * The key-down status bit is cleared when the On/Off button
> > + * is released.
> > + */
> > + input_report_key(onkey->input_dev, KEY_POWER, 0);
> > + input_sync(onkey->input_dev);
> > +
> > + reg_bits = onkey->params->long_int_pnd_bm |
> > + onkey->params->short_int_pnd_bm |
> > + onkey->params->kdwn_int_pnd_bm |
> > + onkey->params->press_int_en_bm |
> > + onkey->params->kdwn_int_en_bm;
> > +
> > + /* Clear key press pending events and enable key press interrupts. */
> > + regmap_update_bits(onkey->atc260x->regmap, onkey->params->reg_int_ctl,
> > + reg_bits, reg_bits);
> > +}
> > +
> > +static void atc260x_onkey_work(struct work_struct *work)
> > +{
> > + struct atc260x_onkey *onkey = container_of(work, struct atc260x_onkey,
> > + work.work);
> > + atc260x_onkey_query(onkey);
> > +}
> > +
> > +static irqreturn_t atc260x_onkey_irq(int irq, void *data)
> > +{
> > + struct atc260x_onkey *onkey = data;
> > + int ret;
> > +
> > + /* Disable key press interrupts. */
> > + ret = regmap_update_bits(onkey->atc260x->regmap,
> > + onkey->params->reg_int_ctl,
> > + onkey->params->press_int_en_bm |
> > + onkey->params->kdwn_int_en_bm, 0);
> > + if (ret)
> > + dev_err(onkey->atc260x->dev,
> > + "Failed to disable interrupts: %d\n", ret);
> > +
> > + input_report_key(onkey->input_dev, KEY_POWER, 1);
> > + input_sync(onkey->input_dev);
> > +
> > + atc260x_onkey_query(onkey);
> > +
> > + return IRQ_HANDLED;
> > +}
> > +
> > +static int atc260x_onkey_probe(struct platform_device *pdev)
> > +{
> > + struct atc260x *atc260x = dev_get_drvdata(pdev->dev.parent);
> > + struct atc260x_onkey *onkey;
> > + struct input_dev *input_dev;
> > + enum atc260x_onkey_reset_status reset_status;
> > + u32 press_time = KEY_PRESS_TIME_SEC, reset_time = 0;
> > + int val, irq, ret;
> > +
> > + if (!pdev->dev.of_node)
> > + return -ENXIO;
>
> Why is this needed?
The idea was to allow the user enable/disable the ONKEY functionality
of the MFD device via the 'onkey' DTS node. So if this node is not
present, the driver will not be loaded.
Is there a better/recommended way to handle this scenario?
> > +
> > + onkey = devm_kzalloc(&pdev->dev, sizeof(*onkey), GFP_KERNEL);
> > + if (!onkey)
> > + return -ENOMEM;
> > +
> > + ret = device_property_read_u32(&pdev->dev,
> > + "actions,reset-time-sec", &val);
>
> Call this "error" please.
Would something like bellow suffice?
if (ret) {
dev_err(&pdev->dev, "Failed to read actions,reset-time-sec\n");
return ret;
}
> > + if (ret) {
> > + reset_status = KEY_RESET_HW_DEFAULT;
> > + } else if (val) {
> > + if (val < 6 || val > 12) {
> > + dev_err(&pdev->dev, "actions,reset-time-sec out of range\n");
> > + return -EINVAL;
> > + }
> > +
> > + reset_status = KEY_RESET_USER_SEL;
> > + reset_time = (val - 6) / 2;
> > + } else {
> > + reset_status = KEY_RESET_DISABLED;
> > + dev_info(&pdev->dev, "Disabled reset on long-press\n");
> > + }
> > +
> > + switch (atc260x->ic_type) {
> > + case ATC2603C:
> > + onkey->params = &atc2603c_onkey_params;
> > + press_time = FIELD_PREP(ATC2603C_PMU_SYS_CTL2_ONOFF_PRESS_TIME,
> > + press_time);
> > + reset_time = FIELD_PREP(ATC2603C_PMU_SYS_CTL2_ONOFF_RESET_TIME_SEL,
> > + reset_time);
> > + break;
> > + case ATC2609A:
> > + onkey->params = &atc2609a_onkey_params;
> > + press_time = FIELD_PREP(ATC2609A_PMU_SYS_CTL2_ONOFF_PRESS_TIME,
> > + press_time);
> > + reset_time = FIELD_PREP(ATC2609A_PMU_SYS_CTL2_ONOFF_RESET_TIME_SEL,
> > + reset_time);
> > + break;
> > + default:
> > + dev_err(&pdev->dev,
> > + "OnKey not supported for ATC260x PMIC type: %u\n",
> > + atc260x->ic_type);
> > + return -EINVAL;
> > + }
> > +
> > + input_dev = devm_input_allocate_device(&pdev->dev);
> > + if (!input_dev) {
> > + dev_err(&pdev->dev, "Failed to allocate input device\n");
> > + return -ENOMEM;
> > + }
> > +
> > + onkey->input_dev = input_dev;
> > + onkey->atc260x = atc260x;
> > +
> > + input_dev->name = "atc260x-onkey";
> > + input_dev->phys = "atc260x-onkey/input0";
> > + input_dev->evbit[0] = BIT_MASK(EV_KEY);
>
> Not needed.
Done.
> > + input_set_capability(input_dev, EV_KEY, KEY_POWER);
> > +
> > + INIT_DELAYED_WORK(&onkey->work, atc260x_onkey_work);
> > +
> > + irq = platform_get_irq(pdev, 0);
> > + if (irq < 0)
> > + return irq;
> > +
> > + ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
> > + atc260x_onkey_irq,
> > + IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
>
> Do we need to force the trigger type? Can we rely on the parent to
> configure it as needed?
Done, I removed the trigger type enforcement.
> > + dev_name(&pdev->dev), onkey);
> > + if (ret) {
> > + dev_err(&pdev->dev,
> > + "Failed to register IRQ %d: %d\n", irq, ret);
> > + return ret;
> > + }
> > +
> > + ret = input_register_device(input_dev);
> > + if (ret) {
> > + dev_err(&pdev->dev,
> > + "Failed to register input device: %d\n", ret);
> > + return ret;
> > + }
> > +
> > + ret = atc2603x_onkey_hw_init(onkey, reset_status,
> > + reset_time, press_time);
> > + if (ret)
> > + return ret;
> > +
> > + platform_set_drvdata(pdev, onkey);
> > + device_init_wakeup(&pdev->dev, true);
> > +
> > + return 0;
> > +}
> > +
> > +static int atc260x_onkey_remove(struct platform_device *pdev)
> > +{
> > + struct atc260x_onkey *onkey = platform_get_drvdata(pdev);
> > +
> > + cancel_delayed_work_sync(&onkey->work);
>
> This is racy. Past this point the interrupts are not disabled, so if key
> happens to be pressed you will re-schedule the work and it will go BOOM.
>
> You are using threaded interrupt. Maybe consider sleeping and
> re-checking the key status right there.
I've seen this approach in a few drivers: da9055_onkey.c,
palmas-pwrbutton.c, wm831x-on.c
I noticed they also call 'free_irq()' right before
'cancel_delayed_work_sync()'. Would this help mitigate the racing issue?
> > +
> > + return 0;
> > +}
> > +
> > +static const struct of_device_id atc260x_onkey_of_match[] = {
> > + { .compatible = "actions,atc2603c-onkey" },
> > + { .compatible = "actions,atc2609a-onkey" },
> > + { /* sentinel */ }
> > +};
> > +MODULE_DEVICE_TABLE(of, atc260x_onkey_of_match);
> > +
> > +static struct platform_driver atc260x_onkey_driver = {
> > + .probe = atc260x_onkey_probe,
> > + .remove = atc260x_onkey_remove,
> > + .driver = {
> > + .name = "atc260x-onkey",
> > + .of_match_table = of_match_ptr(atc260x_onkey_of_match),
> > + },
> > +};
> > +
> > +module_platform_driver(atc260x_onkey_driver);
> > +
> > +MODULE_DESCRIPTION("Onkey driver for ATC260x PMICs");
> > +MODULE_AUTHOR("Cristian Ciocaltea <cristian.ciocaltea@xxxxxxxxx>");
> > +MODULE_LICENSE("GPL");
> > --
> > 2.28.0
> >
>
> Thanks.
>
> --
> Dmitry
Kind regards,
Cristi
