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path: root/drivers/input/serio/ams_delta_serio.c
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Diffstat (limited to 'drivers/input/serio/ams_delta_serio.c')
-rw-r--r--drivers/input/serio/ams_delta_serio.c177
1 files changed, 177 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 00000000000..8f1770e1e08
--- /dev/null
+++ b/drivers/input/serio/ams_delta_serio.c
@@ -0,0 +1,177 @@
+/*
+ * 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/gpio.h>
+#include <linux/irq.h>
+#include <linux/serio.h>
+#include <linux/slab.h>
+
+#include <asm/mach-types.h>
+#include <plat/board-ams-delta.h>
+
+#include <mach/ams-delta-fiq.h>
+
+MODULE_AUTHOR("Matt Callow");
+MODULE_DESCRIPTION("AMS Delta (E3) keyboard port driver");
+MODULE_LICENSE("GPL");
+
+static struct serio *ams_delta_serio;
+
+static int check_data(int data)
+{
+ int i, parity = 0;
+
+ /* check valid stop bit */
+ if (!(data & 0x400)) {
+ dev_warn(&ams_delta_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(&ams_delta_serio->dev,
+ "paritiy 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)
+{
+ int *circ_buff = &fiq_buffer[FIQ_CIRC_BUFF];
+ int data, dfl;
+ u8 scancode;
+
+ fiq_buffer[FIQ_IRQ_PEND] = 0;
+
+ /*
+ * Read data from the circular buffer, check it
+ * and then pass it on the serio
+ */
+ while (fiq_buffer[FIQ_KEYS_CNT] > 0) {
+
+ data = circ_buff[fiq_buffer[FIQ_HEAD_OFFSET]++];
+ fiq_buffer[FIQ_KEYS_CNT]--;
+ if (fiq_buffer[FIQ_HEAD_OFFSET] == fiq_buffer[FIQ_BUF_LEN])
+ fiq_buffer[FIQ_HEAD_OFFSET] = 0;
+
+ dfl = check_data(data);
+ scancode = (u8) (data >> 1) & 0xFF;
+ serio_interrupt(ams_delta_serio, scancode, dfl);
+ }
+ return IRQ_HANDLED;
+}
+
+static int ams_delta_serio_open(struct serio *serio)
+{
+ /* enable keyboard */
+ ams_delta_latch2_write(AMD_DELTA_LATCH2_KEYBRD_PWR,
+ AMD_DELTA_LATCH2_KEYBRD_PWR);
+
+ return 0;
+}
+
+static void ams_delta_serio_close(struct serio *serio)
+{
+ /* disable keyboard */
+ ams_delta_latch2_write(AMD_DELTA_LATCH2_KEYBRD_PWR, 0);
+}
+
+static int __init ams_delta_serio_init(void)
+{
+ int err;
+
+ if (!machine_is_ams_delta())
+ return -ENODEV;
+
+ ams_delta_serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
+ if (!ams_delta_serio)
+ return -ENOMEM;
+
+ ams_delta_serio->id.type = SERIO_8042;
+ ams_delta_serio->open = ams_delta_serio_open;
+ ams_delta_serio->close = ams_delta_serio_close;
+ strlcpy(ams_delta_serio->name, "AMS DELTA keyboard adapter",
+ sizeof(ams_delta_serio->name));
+ strlcpy(ams_delta_serio->phys, "GPIO/serio0",
+ sizeof(ams_delta_serio->phys));
+
+ err = gpio_request(AMS_DELTA_GPIO_PIN_KEYBRD_DATA, "serio-data");
+ if (err) {
+ pr_err("ams_delta_serio: Couldn't request gpio pin for data\n");
+ goto serio;
+ }
+ gpio_direction_input(AMS_DELTA_GPIO_PIN_KEYBRD_DATA);
+
+ err = gpio_request(AMS_DELTA_GPIO_PIN_KEYBRD_CLK, "serio-clock");
+ if (err) {
+ pr_err("ams_delta_serio: couldn't request gpio pin for clock\n");
+ goto gpio_data;
+ }
+ gpio_direction_input(AMS_DELTA_GPIO_PIN_KEYBRD_CLK);
+
+ err = request_irq(gpio_to_irq(AMS_DELTA_GPIO_PIN_KEYBRD_CLK),
+ ams_delta_serio_interrupt, IRQ_TYPE_EDGE_RISING,
+ "ams-delta-serio", 0);
+ if (err < 0) {
+ pr_err("ams_delta_serio: couldn't request gpio interrupt %d\n",
+ gpio_to_irq(AMS_DELTA_GPIO_PIN_KEYBRD_CLK));
+ goto gpio_clk;
+ }
+ /*
+ * Since GPIO register handling for keyboard clock pin is performed
+ * at FIQ level, switch back from edge to simple interrupt handler
+ * to avoid bad interaction.
+ */
+ set_irq_handler(gpio_to_irq(AMS_DELTA_GPIO_PIN_KEYBRD_CLK),
+ handle_simple_irq);
+
+ serio_register_port(ams_delta_serio);
+ dev_info(&ams_delta_serio->dev, "%s\n", ams_delta_serio->name);
+
+ return 0;
+gpio_clk:
+ gpio_free(AMS_DELTA_GPIO_PIN_KEYBRD_CLK);
+gpio_data:
+ gpio_free(AMS_DELTA_GPIO_PIN_KEYBRD_DATA);
+serio:
+ kfree(ams_delta_serio);
+ return err;
+}
+module_init(ams_delta_serio_init);
+
+static void __exit ams_delta_serio_exit(void)
+{
+ serio_unregister_port(ams_delta_serio);
+ free_irq(OMAP_GPIO_IRQ(AMS_DELTA_GPIO_PIN_KEYBRD_CLK), 0);
+ gpio_free(AMS_DELTA_GPIO_PIN_KEYBRD_CLK);
+ gpio_free(AMS_DELTA_GPIO_PIN_KEYBRD_DATA);
+ kfree(ams_delta_serio);
+}
+module_exit(ams_delta_serio_exit);