[RFC PATCH 2/3] drivers/mfd: rpisense: Raspberry Pi senseHAT joystick driver
Peter Robinson
pbrobinson at gmail.com
Sat Aug 7 06:05:38 PDT 2021
On Sat, Aug 7, 2021 at 1:31 AM Joel Savitz <jsavitz at redhat.com> wrote:
>
> This patch implements support for the joystick, including a threaded
> IRQ routine.
If you look at this on it's own, remember the cover letter doesn't go
into git, it's not overly descriptive. We know it's a patch. What does
the "threaded IRQ routine" do in the context, why is that specifically
called out.
Something like:
A simple joystick with up/down/left/right and enter attached via i2c
> Signed-off-by: Charles Mirabile <cmirabil at redhat.com>
> Signed-off-by: Mwesigwa Guma <mguma at redhat.com>
> Signed-off-by: Joel Savitz <jsavitz at redhat.com>
> ---
> drivers/mfd/Makefile | 1 +
> drivers/mfd/rpisense-js.c | 132 ++++++++++++++++++++++++++++++++++++++
This driver should be in drivers/input/joystick/
> 2 files changed, 133 insertions(+)
> create mode 100644 drivers/mfd/rpisense-js.c
>
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index 76f9a9221241..71356153ccdc 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -264,6 +264,7 @@ obj-$(CONFIG_MFD_ROHM_BD957XMUF) += rohm-bd9576.o
> obj-$(CONFIG_MFD_STMFX) += stmfx.o
> obj-$(CONFIG_MFD_KHADAS_MCU) += khadas-mcu.o
> obj-$(CONFIG_MFD_RPISENSE) += rpisense-core.o
> +obj-$(CONFIG_MFD_RPISENSE) += rpisense-js.o
While it's unlikely that these will be used without one another I
still believe this needs it's own Kconfig entry.
> obj-$(CONFIG_MFD_ACER_A500_EC) += acer-ec-a500.o
> obj-$(CONFIG_MFD_QCOM_PM8008) += qcom-pm8008.o
>
> diff --git a/drivers/mfd/rpisense-js.c b/drivers/mfd/rpisense-js.c
> new file mode 100644
> index 000000000000..c6c97bff118c
> --- /dev/null
> +++ b/drivers/mfd/rpisense-js.c
> @@ -0,0 +1,132 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Raspberry Pi Sense HAT joystick driver
> + * http://raspberrypi.org
> + *
> + * Copyright (C) 2015 Raspberry Pi
> + * Copyright (C) 2021 Charles Mirabile, Mwesigwa Guma, Joel Savitz
> + *
> + * Original Author: Serge Schneider
> + * Revised for upstream Linux by: Charles Mirabile, Mwesigwa Guma, Joel Savitz
> + */
> +
> +#include <linux/module.h>
> +#include <linux/input.h>
> +#include <linux/i2c.h>
> +#include <linux/interrupt.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/platform_device.h>
> +
> +#include <linux/mfd/rpisense.h>
> +
> +static unsigned char keymap[] = {KEY_DOWN, KEY_RIGHT, KEY_UP, KEY_ENTER, KEY_LEFT,};
> +
> +static irqreturn_t rpisense_js_report(int n, void *cookie)
> +{
> + int i;
> + static s32 prev_keys;
> + struct rpisense *rpisense = cookie;
> + struct rpisense_js *rpisense_js = &rpisense->joystick;
> + s32 keys = rpisense_get_joystick_state(rpisense);
> + s32 changes = keys ^ prev_keys;
> +
> + prev_keys = keys;
> + for (i = 0; i < ARRAY_SIZE(keymap); ++i) {
> + if (changes & (1<<i)) {
> + input_report_key(rpisense_js->keys_dev,
> + keymap[i], keys & (1<<i));
> + }
> + }
> + input_sync(rpisense_js->keys_dev);
> + return IRQ_HANDLED;
> +}
> +
> +static int rpisense_js_probe(struct platform_device *pdev)
> +{
> + int ret;
> + int i;
> + struct rpisense *rpisense = dev_get_drvdata(&pdev->dev);
> + struct rpisense_js *rpisense_js = &rpisense->joystick;
> +
> + rpisense_js->keys_desc = devm_gpiod_get(&rpisense->i2c_client->dev,
> + "keys-int", GPIOD_IN);
> + if (IS_ERR(rpisense_js->keys_desc)) {
> + dev_warn(&pdev->dev, "Failed to get keys-int descriptor.\n");
> + return PTR_ERR(rpisense_js->keys_desc);
> + }
> +
> +
> + rpisense_js->keys_dev = devm_input_allocate_device(&pdev->dev);
> + if (rpisense_js->keys_dev == NULL) {
> + dev_err(&pdev->dev, "Could not allocate input device.\n");
> + return -ENOMEM;
> + }
> +
> + for (i = 0; i < ARRAY_SIZE(keymap); i++) {
> + set_bit(keymap[i],
> + rpisense_js->keys_dev->keybit);
> + }
> +
> + rpisense_js->keys_dev->name = "Raspberry Pi Sense HAT Joystick";
> + rpisense_js->keys_dev->phys = "rpi-sense-joy/input0";
> + rpisense_js->keys_dev->id.bustype = BUS_I2C;
> + rpisense_js->keys_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REP);
> + rpisense_js->keys_dev->keycode = keymap;
> + rpisense_js->keys_dev->keycodesize = sizeof(unsigned char);
> + rpisense_js->keys_dev->keycodemax = ARRAY_SIZE(keymap);
> +
> + ret = input_register_device(rpisense_js->keys_dev);
> + if (ret) {
> + dev_err(&pdev->dev, "Could not register input device.\n");
> + return ret;
> + }
> +
> + ret = gpiod_direction_input(rpisense_js->keys_desc);
> + if (ret) {
> + dev_err(&pdev->dev, "Could not set keys-int direction.\n");
> + return ret;
> + }
> +
> + rpisense_js->keys_irq = gpiod_to_irq(rpisense_js->keys_desc);
> + if (rpisense_js->keys_irq < 0) {
> + dev_err(&pdev->dev, "Could not determine keys-int IRQ.\n");
> + return rpisense_js->keys_irq;
> + }
> +
> + ret = devm_request_threaded_irq(&pdev->dev, rpisense_js->keys_irq,
> + NULL, rpisense_js_report, IRQF_TRIGGER_RISING | IRQF_ONESHOT,
> + "keys", rpisense);
> +
> + if (ret) {
> + dev_err(&pdev->dev, "IRQ request failed.\n");
> + return ret;
> + }
> + return 0;
> +}
> +
> +#ifdef CONFIG_OF
> +static const struct of_device_id rpisense_js_id[] = {
> + { .compatible = "rpi,rpi-sense-js" },
> + { },
> +};
> +MODULE_DEVICE_TABLE(of, rpisense_js_id);
> +#endif
> +
> +static struct platform_device_id rpisense_js_device_id[] = {
> + { .name = "rpi-sense-js" },
> + { },
> +};
> +MODULE_DEVICE_TABLE(platform, rpisense_js_device_id);
> +
> +static struct platform_driver rpisense_js_driver = {
> + .probe = rpisense_js_probe,
> + .driver = {
> + .name = "rpi-sense-js",
> + },
> +};
> +
> +module_platform_driver(rpisense_js_driver);
> +
> +MODULE_DESCRIPTION("Raspberry Pi Sense HAT joystick driver");
> +MODULE_AUTHOR("Serge Schneider <serge at raspberrypi.org>");
If you're leaving Serge as the module author should be copied in the
patch series.
> +MODULE_LICENSE("GPL");
> --
> 2.27.0
>
>
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