1 files changed, 380 insertions, 0 deletions
diff --git a/drivers/auxdisplay/cfag12864b.c b/drivers/auxdisplay/cfag12864b.c
new file mode 100644
index 000000000..6526aa51f
--- /dev/null
+++ b/drivers/auxdisplay/cfag12864b.c
@@ -0,0 +1,380 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *    Filename: cfag12864b.c
+ *     Version: 0.1.0
+ * Description: cfag12864b LCD driver
+ *     Depends: ks0108
+ *
+ *      Author: Copyright (C) Miguel Ojeda <ojeda@kernel.org>
+ *        Date: 2006-10-31
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/cdev.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/jiffies.h>
+#include <linux/mutex.h>
+#include <linux/uaccess.h>
+#include <linux/vmalloc.h>
+#include <linux/workqueue.h>
+#include <linux/ks0108.h>
+#include <linux/cfag12864b.h>
+
+
+#define CFAG12864B_NAME "cfag12864b"
+
+/*
+ * Module Parameters
+ */
+
+static unsigned int cfag12864b_rate = CONFIG_CFAG12864B_RATE;
+module_param(cfag12864b_rate, uint, 0444);
+MODULE_PARM_DESC(cfag12864b_rate,
+	"Refresh rate (hertz)");
+
+unsigned int cfag12864b_getrate(void)
+{
+	return cfag12864b_rate;
+}
+
+/*
+ * cfag12864b Commands
+ *
+ *	E = Enable signal
+ *		Every time E switch from low to high,
+ *		cfag12864b/ks0108 reads the command/data.
+ *
+ *	CS1 = First ks0108controller.
+ *		If high, the first ks0108 controller receives commands/data.
+ *
+ *	CS2 = Second ks0108 controller
+ *		If high, the second ks0108 controller receives commands/data.
+ *
+ *	DI = Data/Instruction
+ *		If low, cfag12864b will expect commands.
+ *		If high, cfag12864b will expect data.
+ *
+ */
+
+#define bit(n) (((unsigned char)1)<<(n))
+
+#define CFAG12864B_BIT_E	(0)
+#define CFAG12864B_BIT_CS1	(2)
+#define CFAG12864B_BIT_CS2	(1)
+#define CFAG12864B_BIT_DI	(3)
+
+static unsigned char cfag12864b_state;
+
+static void cfag12864b_set(void)
+{
+	ks0108_writecontrol(cfag12864b_state);
+}
+
+static void cfag12864b_setbit(unsigned char state, unsigned char n)
+{
+	if (state)
+		cfag12864b_state |= bit(n);
+	else
+		cfag12864b_state &= ~bit(n);
+}
+
+static void cfag12864b_e(unsigned char state)
+{
+	cfag12864b_setbit(state, CFAG12864B_BIT_E);
+	cfag12864b_set();
+}
+
+static void cfag12864b_cs1(unsigned char state)
+{
+	cfag12864b_setbit(state, CFAG12864B_BIT_CS1);
+}
+
+static void cfag12864b_cs2(unsigned char state)
+{
+	cfag12864b_setbit(state, CFAG12864B_BIT_CS2);
+}
+
+static void cfag12864b_di(unsigned char state)
+{
+	cfag12864b_setbit(state, CFAG12864B_BIT_DI);
+}
+
+static void cfag12864b_setcontrollers(unsigned char first,
+	unsigned char second)
+{
+	if (first)
+		cfag12864b_cs1(0);
+	else
+		cfag12864b_cs1(1);
+
+	if (second)
+		cfag12864b_cs2(0);
+	else
+		cfag12864b_cs2(1);
+}
+
+static void cfag12864b_controller(unsigned char which)
+{
+	if (which == 0)
+		cfag12864b_setcontrollers(1, 0);
+	else if (which == 1)
+		cfag12864b_setcontrollers(0, 1);
+}
+
+static void cfag12864b_displaystate(unsigned char state)
+{
+	cfag12864b_di(0);
+	cfag12864b_e(1);
+	ks0108_displaystate(state);
+	cfag12864b_e(0);
+}
+
+static void cfag12864b_address(unsigned char address)
+{
+	cfag12864b_di(0);
+	cfag12864b_e(1);
+	ks0108_address(address);
+	cfag12864b_e(0);
+}
+
+static void cfag12864b_page(unsigned char page)
+{
+	cfag12864b_di(0);
+	cfag12864b_e(1);
+	ks0108_page(page);
+	cfag12864b_e(0);
+}
+
+static void cfag12864b_startline(unsigned char startline)
+{
+	cfag12864b_di(0);
+	cfag12864b_e(1);
+	ks0108_startline(startline);
+	cfag12864b_e(0);
+}
+
+static void cfag12864b_writebyte(unsigned char byte)
+{
+	cfag12864b_di(1);
+	cfag12864b_e(1);
+	ks0108_writedata(byte);
+	cfag12864b_e(0);
+}
+
+static void cfag12864b_nop(void)
+{
+	cfag12864b_startline(0);
+}
+
+/*
+ * cfag12864b Internal Commands
+ */
+
+static void cfag12864b_on(void)
+{
+	cfag12864b_setcontrollers(1, 1);
+	cfag12864b_displaystate(1);
+}
+
+static void cfag12864b_off(void)
+{
+	cfag12864b_setcontrollers(1, 1);
+	cfag12864b_displaystate(0);
+}
+
+static void cfag12864b_clear(void)
+{
+	unsigned char i, j;
+
+	cfag12864b_setcontrollers(1, 1);
+	for (i = 0; i < CFAG12864B_PAGES; i++) {
+		cfag12864b_page(i);
+		cfag12864b_address(0);
+		for (j = 0; j < CFAG12864B_ADDRESSES; j++)
+			cfag12864b_writebyte(0);
+	}
+}
+
+/*
+ * Update work
+ */
+
+unsigned char *cfag12864b_buffer;
+static unsigned char *cfag12864b_cache;
+static DEFINE_MUTEX(cfag12864b_mutex);
+static unsigned char cfag12864b_updating;
+static void cfag12864b_update(struct work_struct *delayed_work);
+static struct workqueue_struct *cfag12864b_workqueue;
+static DECLARE_DELAYED_WORK(cfag12864b_work, cfag12864b_update);
+
+static void cfag12864b_queue(void)
+{
+	queue_delayed_work(cfag12864b_workqueue, &cfag12864b_work,
+		HZ / cfag12864b_rate);
+}
+
+unsigned char cfag12864b_enable(void)
+{
+	unsigned char ret;
+
+	mutex_lock(&cfag12864b_mutex);
+
+	if (!cfag12864b_updating) {
+		cfag12864b_updating = 1;
+		cfag12864b_queue();
+		ret = 0;
+	} else
+		ret = 1;
+
+	mutex_unlock(&cfag12864b_mutex);
+
+	return ret;
+}
+
+void cfag12864b_disable(void)
+{
+	mutex_lock(&cfag12864b_mutex);
+
+	if (cfag12864b_updating) {
+		cfag12864b_updating = 0;
+		cancel_delayed_work(&cfag12864b_work);
+		flush_workqueue(cfag12864b_workqueue);
+	}
+
+	mutex_unlock(&cfag12864b_mutex);
+}
+
+unsigned char cfag12864b_isenabled(void)
+{
+	return cfag12864b_updating;
+}
+
+static void cfag12864b_update(struct work_struct *work)
+{
+	unsigned char c;
+	unsigned short i, j, k, b;
+
+	if (memcmp(cfag12864b_cache, cfag12864b_buffer, CFAG12864B_SIZE)) {
+		for (i = 0; i < CFAG12864B_CONTROLLERS; i++) {
+			cfag12864b_controller(i);
+			cfag12864b_nop();
+			for (j = 0; j < CFAG12864B_PAGES; j++) {
+				cfag12864b_page(j);
+				cfag12864b_nop();
+				cfag12864b_address(0);
+				cfag12864b_nop();
+				for (k = 0; k < CFAG12864B_ADDRESSES; k++) {
+					for (c = 0, b = 0; b < 8; b++)
+						if (cfag12864b_buffer
+							[i * CFAG12864B_ADDRESSES / 8
+							+ k / 8 + (j * 8 + b) *
+							CFAG12864B_WIDTH / 8]
+							& bit(k % 8))
+							c |= bit(b);
+					cfag12864b_writebyte(c);
+				}
+			}
+		}
+
+		memcpy(cfag12864b_cache, cfag12864b_buffer, CFAG12864B_SIZE);
+	}
+
+	if (cfag12864b_updating)
+		cfag12864b_queue();
+}
+
+/*
+ * cfag12864b Exported Symbols
+ */
+
+EXPORT_SYMBOL_GPL(cfag12864b_buffer);
+EXPORT_SYMBOL_GPL(cfag12864b_getrate);
+EXPORT_SYMBOL_GPL(cfag12864b_enable);
+EXPORT_SYMBOL_GPL(cfag12864b_disable);
+EXPORT_SYMBOL_GPL(cfag12864b_isenabled);
+
+/*
+ * Is the module inited?
+ */
+
+static unsigned char cfag12864b_inited;
+unsigned char cfag12864b_isinited(void)
+{
+	return cfag12864b_inited;
+}
+EXPORT_SYMBOL_GPL(cfag12864b_isinited);
+
+/*
+ * Module Init & Exit
+ */
+
+static int __init cfag12864b_init(void)
+{
+	int ret = -EINVAL;
+
+	/* ks0108_init() must be called first */
+	if (!ks0108_isinited()) {
+		printk(KERN_ERR CFAG12864B_NAME ": ERROR: "
+			"ks0108 is not initialized\n");
+		goto none;
+	}
+	BUILD_BUG_ON(PAGE_SIZE < CFAG12864B_SIZE);
+
+	cfag12864b_buffer = (unsigned char *) get_zeroed_page(GFP_KERNEL);
+	if (cfag12864b_buffer == NULL) {
+		printk(KERN_ERR CFAG12864B_NAME ": ERROR: "
+			"can't get a free page\n");
+		ret = -ENOMEM;
+		goto none;
+	}
+
+	cfag12864b_cache = kmalloc(CFAG12864B_SIZE,
+				   GFP_KERNEL);
+	if (cfag12864b_cache == NULL) {
+		printk(KERN_ERR CFAG12864B_NAME ": ERROR: "
+			"can't alloc cache buffer (%i bytes)\n",
+			CFAG12864B_SIZE);
+		ret = -ENOMEM;
+		goto bufferalloced;
+	}
+
+	cfag12864b_workqueue = create_singlethread_workqueue(CFAG12864B_NAME);
+	if (cfag12864b_workqueue == NULL)
+		goto cachealloced;
+
+	cfag12864b_clear();
+	cfag12864b_on();
+
+	cfag12864b_inited = 1;
+	return 0;
+
+cachealloced:
+	kfree(cfag12864b_cache);
+
+bufferalloced:
+	free_page((unsigned long) cfag12864b_buffer);
+
+none:
+	return ret;
+}
+
+static void __exit cfag12864b_exit(void)
+{
+	cfag12864b_disable();
+	cfag12864b_off();
+	destroy_workqueue(cfag12864b_workqueue);
+	kfree(cfag12864b_cache);
+	free_page((unsigned long) cfag12864b_buffer);
+}
+
+module_init(cfag12864b_init);
+module_exit(cfag12864b_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Miguel Ojeda <ojeda@kernel.org>");
+MODULE_DESCRIPTION("cfag12864b LCD driver");