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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
commit76cb841cb886eef6b3bee341a2266c76578724ad (patch)
treef5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /drivers/input/serio/ams_delta_serio.c
parentInitial commit. (diff)
downloadlinux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz
linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/input/serio/ams_delta_serio.c')
-rw-r--r--drivers/input/serio/ams_delta_serio.c195
1 files changed, 195 insertions, 0 deletions
diff --git a/drivers/input/serio/ams_delta_serio.c b/drivers/input/serio/ams_delta_serio.c
new file mode 100644
index 000000000..f8663d789
--- /dev/null
+++ b/drivers/input/serio/ams_delta_serio.c
@@ -0,0 +1,195 @@
+/*
+ * Amstrad E3 (Delta) keyboard port driver
+ *
+ * Copyright (c) 2006 Matt Callow
+ * Copyright (c) 2010 Janusz Krzysztofik
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * Thanks to Cliff Lawson for his help
+ *
+ * The Amstrad Delta keyboard (aka mailboard) uses normal PC-AT style serial
+ * transmission. The keyboard port is formed of two GPIO lines, for clock
+ * and data. Due to strict timing requirements of the interface,
+ * the serial data stream is read and processed by a FIQ handler.
+ * The resulting words are fetched by this driver from a circular buffer.
+ *
+ * Standard AT keyboard driver (atkbd) is used for handling the keyboard data.
+ * However, when used with the E3 mailboard that producecs non-standard
+ * scancodes, a custom key table must be prepared and loaded from userspace.
+ */
+#include <linux/irq.h>
+#include <linux/platform_data/ams-delta-fiq.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+#include <linux/serio.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+
+#define DRIVER_NAME "ams-delta-serio"
+
+MODULE_AUTHOR("Matt Callow");
+MODULE_DESCRIPTION("AMS Delta (E3) keyboard port driver");
+MODULE_LICENSE("GPL");
+
+struct ams_delta_serio {
+ struct serio *serio;
+ struct regulator *vcc;
+ unsigned int *fiq_buffer;
+};
+
+static int check_data(struct serio *serio, int data)
+{
+ int i, parity = 0;
+
+ /* check valid stop bit */
+ if (!(data & 0x400)) {
+ dev_warn(&serio->dev, "invalid stop bit, data=0x%X\n", data);
+ return SERIO_FRAME;
+ }
+ /* calculate the parity */
+ for (i = 1; i < 10; i++) {
+ if (data & (1 << i))
+ parity++;
+ }
+ /* it should be odd */
+ if (!(parity & 0x01)) {
+ dev_warn(&serio->dev,
+ "parity check failed, data=0x%X parity=0x%X\n", data,
+ parity);
+ return SERIO_PARITY;
+ }
+ return 0;
+}
+
+static irqreturn_t ams_delta_serio_interrupt(int irq, void *dev_id)
+{
+ struct ams_delta_serio *priv = dev_id;
+ int *circ_buff = &priv->fiq_buffer[FIQ_CIRC_BUFF];
+ int data, dfl;
+ u8 scancode;
+
+ priv->fiq_buffer[FIQ_IRQ_PEND] = 0;
+
+ /*
+ * Read data from the circular buffer, check it
+ * and then pass it on the serio
+ */
+ while (priv->fiq_buffer[FIQ_KEYS_CNT] > 0) {
+
+ data = circ_buff[priv->fiq_buffer[FIQ_HEAD_OFFSET]++];
+ priv->fiq_buffer[FIQ_KEYS_CNT]--;
+ if (priv->fiq_buffer[FIQ_HEAD_OFFSET] ==
+ priv->fiq_buffer[FIQ_BUF_LEN])
+ priv->fiq_buffer[FIQ_HEAD_OFFSET] = 0;
+
+ dfl = check_data(priv->serio, data);
+ scancode = (u8) (data >> 1) & 0xFF;
+ serio_interrupt(priv->serio, scancode, dfl);
+ }
+ return IRQ_HANDLED;
+}
+
+static int ams_delta_serio_open(struct serio *serio)
+{
+ struct ams_delta_serio *priv = serio->port_data;
+
+ /* enable keyboard */
+ return regulator_enable(priv->vcc);
+}
+
+static void ams_delta_serio_close(struct serio *serio)
+{
+ struct ams_delta_serio *priv = serio->port_data;
+
+ /* disable keyboard */
+ regulator_disable(priv->vcc);
+}
+
+static int ams_delta_serio_init(struct platform_device *pdev)
+{
+ struct ams_delta_serio *priv;
+ struct serio *serio;
+ int irq, err;
+
+ priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->fiq_buffer = pdev->dev.platform_data;
+ if (!priv->fiq_buffer)
+ return -EINVAL;
+
+ priv->vcc = devm_regulator_get(&pdev->dev, "vcc");
+ if (IS_ERR(priv->vcc)) {
+ err = PTR_ERR(priv->vcc);
+ dev_err(&pdev->dev, "regulator request failed (%d)\n", err);
+ /*
+ * When running on a non-dt platform and requested regulator
+ * is not available, devm_regulator_get() never returns
+ * -EPROBE_DEFER as it is not able to justify if the regulator
+ * may still appear later. On the other hand, the board can
+ * still set full constriants flag at late_initcall in order
+ * to instruct devm_regulator_get() to returnn a dummy one
+ * if sufficient. Hence, if we get -ENODEV here, let's convert
+ * it to -EPROBE_DEFER and wait for the board to decide or
+ * let Deferred Probe infrastructure handle this error.
+ */
+ if (err == -ENODEV)
+ err = -EPROBE_DEFER;
+ return err;
+ }
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0)
+ return -ENXIO;
+
+ err = devm_request_irq(&pdev->dev, irq, ams_delta_serio_interrupt,
+ IRQ_TYPE_EDGE_RISING, DRIVER_NAME, priv);
+ if (err < 0) {
+ dev_err(&pdev->dev, "IRQ request failed (%d)\n", err);
+ return err;
+ }
+
+ serio = kzalloc(sizeof(*serio), GFP_KERNEL);
+ if (!serio)
+ return -ENOMEM;
+
+ priv->serio = serio;
+
+ serio->id.type = SERIO_8042;
+ serio->open = ams_delta_serio_open;
+ serio->close = ams_delta_serio_close;
+ strlcpy(serio->name, "AMS DELTA keyboard adapter", sizeof(serio->name));
+ strlcpy(serio->phys, dev_name(&pdev->dev), sizeof(serio->phys));
+ serio->dev.parent = &pdev->dev;
+ serio->port_data = priv;
+
+ serio_register_port(serio);
+
+ platform_set_drvdata(pdev, priv);
+
+ dev_info(&serio->dev, "%s\n", serio->name);
+
+ return 0;
+}
+
+static int ams_delta_serio_exit(struct platform_device *pdev)
+{
+ struct ams_delta_serio *priv = platform_get_drvdata(pdev);
+
+ serio_unregister_port(priv->serio);
+
+ return 0;
+}
+
+static struct platform_driver ams_delta_serio_driver = {
+ .probe = ams_delta_serio_init,
+ .remove = ams_delta_serio_exit,
+ .driver = {
+ .name = DRIVER_NAME
+ },
+};
+module_platform_driver(ams_delta_serio_driver);