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-rw-r--r--drivers/auxdisplay/ks0108.c172
1 files changed, 172 insertions, 0 deletions
diff --git a/drivers/auxdisplay/ks0108.c b/drivers/auxdisplay/ks0108.c
new file mode 100644
index 0000000000..234f9dbe6e
--- /dev/null
+++ b/drivers/auxdisplay/ks0108.c
@@ -0,0 +1,172 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Filename: ks0108.c
+ * Version: 0.1.0
+ * Description: ks0108 LCD Controller driver
+ * Depends: parport
+ *
+ * Author: Copyright (C) Miguel Ojeda <ojeda@kernel.org>
+ * Date: 2006-10-31
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/parport.h>
+#include <linux/ks0108.h>
+
+#define KS0108_NAME "ks0108"
+
+/*
+ * Module Parameters
+ */
+
+static unsigned int ks0108_port = CONFIG_KS0108_PORT;
+module_param(ks0108_port, uint, 0444);
+MODULE_PARM_DESC(ks0108_port, "Parallel port where the LCD is connected");
+
+static unsigned int ks0108_delay = CONFIG_KS0108_DELAY;
+module_param(ks0108_delay, uint, 0444);
+MODULE_PARM_DESC(ks0108_delay, "Delay between each control writing (microseconds)");
+
+/*
+ * Device
+ */
+
+static struct parport *ks0108_parport;
+static struct pardevice *ks0108_pardevice;
+
+/*
+ * ks0108 Exported Commands (don't lock)
+ *
+ * You _should_ lock in the top driver: This functions _should not_
+ * get race conditions in any way. Locking for each byte here would be
+ * so slow and useless.
+ *
+ * There are not bit definitions because they are not flags,
+ * just arbitrary combinations defined by the documentation for each
+ * function in the ks0108 LCD controller. If you want to know what means
+ * a specific combination, look at the function's name.
+ *
+ * The ks0108_writecontrol bits need to be reverted ^(0,1,3) because
+ * the parallel port also revert them using a "not" logic gate.
+ */
+
+#define bit(n) (((unsigned char)1)<<(n))
+
+void ks0108_writedata(unsigned char byte)
+{
+ parport_write_data(ks0108_parport, byte);
+}
+
+void ks0108_writecontrol(unsigned char byte)
+{
+ udelay(ks0108_delay);
+ parport_write_control(ks0108_parport, byte ^ (bit(0) | bit(1) | bit(3)));
+}
+
+void ks0108_displaystate(unsigned char state)
+{
+ ks0108_writedata((state ? bit(0) : 0) | bit(1) | bit(2) | bit(3) | bit(4) | bit(5));
+}
+
+void ks0108_startline(unsigned char startline)
+{
+ ks0108_writedata(min_t(unsigned char, startline, 63) | bit(6) |
+ bit(7));
+}
+
+void ks0108_address(unsigned char address)
+{
+ ks0108_writedata(min_t(unsigned char, address, 63) | bit(6));
+}
+
+void ks0108_page(unsigned char page)
+{
+ ks0108_writedata(min_t(unsigned char, page, 7) | bit(3) | bit(4) |
+ bit(5) | bit(7));
+}
+
+EXPORT_SYMBOL_GPL(ks0108_writedata);
+EXPORT_SYMBOL_GPL(ks0108_writecontrol);
+EXPORT_SYMBOL_GPL(ks0108_displaystate);
+EXPORT_SYMBOL_GPL(ks0108_startline);
+EXPORT_SYMBOL_GPL(ks0108_address);
+EXPORT_SYMBOL_GPL(ks0108_page);
+
+/*
+ * Is the module inited?
+ */
+
+static unsigned char ks0108_inited;
+unsigned char ks0108_isinited(void)
+{
+ return ks0108_inited;
+}
+EXPORT_SYMBOL_GPL(ks0108_isinited);
+
+static void ks0108_parport_attach(struct parport *port)
+{
+ struct pardev_cb ks0108_cb;
+
+ if (port->base != ks0108_port)
+ return;
+
+ memset(&ks0108_cb, 0, sizeof(ks0108_cb));
+ ks0108_cb.flags = PARPORT_DEV_EXCL;
+ ks0108_pardevice = parport_register_dev_model(port, KS0108_NAME,
+ &ks0108_cb, 0);
+ if (!ks0108_pardevice) {
+ pr_err("ERROR: parport didn't register new device\n");
+ return;
+ }
+ if (parport_claim(ks0108_pardevice)) {
+ pr_err("could not claim access to parport %i. Aborting.\n",
+ ks0108_port);
+ goto err_unreg_device;
+ }
+
+ ks0108_parport = port;
+ ks0108_inited = 1;
+ return;
+
+err_unreg_device:
+ parport_unregister_device(ks0108_pardevice);
+ ks0108_pardevice = NULL;
+}
+
+static void ks0108_parport_detach(struct parport *port)
+{
+ if (port->base != ks0108_port)
+ return;
+
+ if (!ks0108_pardevice) {
+ pr_err("%s: already unregistered.\n", KS0108_NAME);
+ return;
+ }
+
+ parport_release(ks0108_pardevice);
+ parport_unregister_device(ks0108_pardevice);
+ ks0108_pardevice = NULL;
+ ks0108_parport = NULL;
+}
+
+/*
+ * Module Init & Exit
+ */
+
+static struct parport_driver ks0108_parport_driver = {
+ .name = "ks0108",
+ .match_port = ks0108_parport_attach,
+ .detach = ks0108_parport_detach,
+ .devmodel = true,
+};
+module_parport_driver(ks0108_parport_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Miguel Ojeda <ojeda@kernel.org>");
+MODULE_DESCRIPTION("ks0108 LCD Controller driver");
+