iio: proximity: vl53l0x-i2c: claim direct mode for raw readsgrafted

vl53l0x_read_raw() starts a single-shot ranging measurement and reads
back the result. Once the triggered buffer is enabled the sensor runs in
continuous mode and its data-ready interrupt is routed to the trigger,
so a concurrent in_distance_raw read disturbs the streaming setup and
never gets its completion, returning -ETIMEDOUT.

The original submission claimed direct mode here, but it was dropped
during review because the driver had no buffer support at the time [1].
Continuous (buffered) mode was later added without restoring the
claim [2], reintroducing the conflict.

Reject direct reads while buffered capture is active by claiming direct
mode around the measurement, as the vl53l1x sibling already does.

Fixes: 762186c6e7b1 ("iio: proximity: vl53l0x-i2c: Added continuous mode support")
Link: https://lore.kernel.org/linux-iio/20180911160300.GA9212@himanshu-Vostro-3559/ [1]
Link: https://lore.kernel.org/linux-iio/20240909101508.263085-3-abhashkumarjha123@gmail.com/ [2]
Signed-off-by: Donggeun Yoo <donggeunyoo.kernel@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jonathan Cameron <jonathan.cameron@oss.qualcomm.com>

1 files changed, 149 insertions, 0 deletions

diff --git a/drivers/input/keyboard/newtonkbd.c b/drivers/input/keyboard/newtonkbd.c
new file mode 100644
index 000000000..e60d1181d
--- /dev/null
+++ b/drivers/input/keyboard/newtonkbd.c
@@ -0,0 +1,149 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Copyright (c) 2000 Justin Cormack
+ */
+
+/*
+ * Newton keyboard driver for Linux
+ */
+
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/input.h>
+#include <linux/serio.h>
+
+#define DRIVER_DESC	"Newton keyboard driver"
+
+MODULE_AUTHOR("Justin Cormack <j.cormack@doc.ic.ac.uk>");
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");
+
+#define NKBD_KEY	0x7f
+#define NKBD_PRESS	0x80
+
+static unsigned char nkbd_keycode[128] = {
+	KEY_A, KEY_S, KEY_D, KEY_F, KEY_H, KEY_G, KEY_Z, KEY_X,
+	KEY_C, KEY_V, 0, KEY_B, KEY_Q, KEY_W, KEY_E, KEY_R,
+	KEY_Y, KEY_T, KEY_1, KEY_2, KEY_3, KEY_4, KEY_6, KEY_5,
+	KEY_EQUAL, KEY_9, KEY_7, KEY_MINUS, KEY_8, KEY_0, KEY_RIGHTBRACE, KEY_O,
+	KEY_U, KEY_LEFTBRACE, KEY_I, KEY_P, KEY_ENTER, KEY_L, KEY_J, KEY_APOSTROPHE,
+	KEY_K, KEY_SEMICOLON, KEY_BACKSLASH, KEY_COMMA, KEY_SLASH, KEY_N, KEY_M, KEY_DOT,
+	KEY_TAB, KEY_SPACE, KEY_GRAVE, KEY_DELETE, 0, 0, 0, KEY_LEFTMETA,
+	KEY_LEFTSHIFT, KEY_CAPSLOCK, KEY_LEFTALT, KEY_LEFTCTRL, KEY_RIGHTSHIFT, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	KEY_LEFT, KEY_RIGHT, KEY_DOWN, KEY_UP, 0
+};
+
+struct nkbd {
+	unsigned char keycode[128];
+	struct input_dev *dev;
+	struct serio *serio;
+	char phys[32];
+};
+
+static irqreturn_t nkbd_interrupt(struct serio *serio,
+		unsigned char data, unsigned int flags)
+{
+	struct nkbd *nkbd = serio_get_drvdata(serio);
+
+	/* invalid scan codes are probably the init sequence, so we ignore them */
+	if (nkbd->keycode[data & NKBD_KEY]) {
+		input_report_key(nkbd->dev, nkbd->keycode[data & NKBD_KEY], data & NKBD_PRESS);
+		input_sync(nkbd->dev);
+	}
+
+	else if (data == 0xe7) /* end of init sequence */
+		printk(KERN_INFO "input: %s on %s\n", nkbd->dev->name, serio->phys);
+	return IRQ_HANDLED;
+
+}
+
+static int nkbd_connect(struct serio *serio, struct serio_driver *drv)
+{
+	struct nkbd *nkbd;
+	struct input_dev *input_dev;
+	int err = -ENOMEM;
+	int i;
+
+	nkbd = kzalloc_obj(*nkbd);
+	input_dev = input_allocate_device();
+	if (!nkbd || !input_dev)
+		goto fail1;
+
+	nkbd->serio = serio;
+	nkbd->dev = input_dev;
+	snprintf(nkbd->phys, sizeof(nkbd->phys), "%s/input0", serio->phys);
+	memcpy(nkbd->keycode, nkbd_keycode, sizeof(nkbd->keycode));
+
+	input_dev->name = "Newton Keyboard";
+	input_dev->phys = nkbd->phys;
+	input_dev->id.bustype = BUS_RS232;
+	input_dev->id.vendor = SERIO_NEWTON;
+	input_dev->id.product = 0x0001;
+	input_dev->id.version = 0x0100;
+	input_dev->dev.parent = &serio->dev;
+
+	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REP);
+	input_dev->keycode = nkbd->keycode;
+	input_dev->keycodesize = sizeof(unsigned char);
+	input_dev->keycodemax = ARRAY_SIZE(nkbd_keycode);
+	for (i = 0; i < 128; i++)
+		set_bit(nkbd->keycode[i], input_dev->keybit);
+	clear_bit(0, input_dev->keybit);
+
+	serio_set_drvdata(serio, nkbd);
+
+	err = serio_open(serio, drv);
+	if (err)
+		goto fail2;
+
+	err = input_register_device(nkbd->dev);
+	if (err)
+		goto fail3;
+
+	return 0;
+
+ fail3:	serio_close(serio);
+ fail2:	serio_set_drvdata(serio, NULL);
+ fail1:	input_free_device(input_dev);
+	kfree(nkbd);
+	return err;
+}
+
+static void nkbd_disconnect(struct serio *serio)
+{
+	struct nkbd *nkbd = serio_get_drvdata(serio);
+
+	serio_close(serio);
+	serio_set_drvdata(serio, NULL);
+	input_unregister_device(nkbd->dev);
+	kfree(nkbd);
+}
+
+static const struct serio_device_id nkbd_serio_ids[] = {
+	{
+		.type	= SERIO_RS232,
+		.proto	= SERIO_NEWTON,
+		.id	= SERIO_ANY,
+		.extra	= SERIO_ANY,
+	},
+	{ 0 }
+};
+
+MODULE_DEVICE_TABLE(serio, nkbd_serio_ids);
+
+static struct serio_driver nkbd_drv = {
+	.driver		= {
+		.name	= "newtonkbd",
+	},
+	.description	= DRIVER_DESC,
+	.id_table	= nkbd_serio_ids,
+	.interrupt	= nkbd_interrupt,
+	.connect	= nkbd_connect,
+	.disconnect	= nkbd_disconnect,
+};
+
+module_serio_driver(nkbd_drv);