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auxdisplay: ht16k33: Driver for LED controller

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Added a driver for the Holtek HT16K33 LED controller with keyscan.

Signed-off-by: Robin van der Gracht <robin@protonic.nl>
CC: Miguel Ojeda Sandonis <miguel.ojeda.sandonis@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Robin van der Gracht 2016-11-07 10:56:35 +01:00 committed by Greg Kroah-Hartman
parent 7279b238ba
commit 8992da44c6
4 changed files with 615 additions and 0 deletions
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42
Documentation/devicetree/bindings/display/ht16k33.txt Normal file
View file

@ -0,0 +1,42 @@
Holtek ht16k33 RAM mapping 16*8 LED controller driver with keyscan
-------------------------------------------------------------------------------
Required properties:
- compatible: "holtek,ht16k33"
- reg: I2C slave address of the chip.
- interrupt-parent: A phandle pointing to the interrupt controller
serving the interrupt for this chip.
- interrupts: Interrupt specification for the key pressed interrupt.
- refresh-rate-hz: Display update interval in HZ.
- debounce-delay-ms: Debouncing interval time in milliseconds.
- linux,keymap: The keymap for keys as described in the binding
document (devicetree/bindings/input/matrix-keymap.txt).
Optional properties:
- linux,no-autorepeat: Disable keyrepeat.
- default-brightness-level: Initial brightness level [0-15] (default: 15).
Example:
&i2c1 {
ht16k33: ht16k33@70 {
compatible = "holtek,ht16k33";
reg = <0x70>;
refresh-rate-hz = <20>;
debounce-delay-ms = <50>;
interrupt-parent = <&gpio4>;
interrupts = <5 (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_EDGE_RISING)>;
linux,keymap = <
MATRIX_KEY(2, 0, KEY_F6)
MATRIX_KEY(3, 0, KEY_F8)
MATRIX_KEY(4, 0, KEY_F10)
MATRIX_KEY(5, 0, KEY_F4)
MATRIX_KEY(6, 0, KEY_F2)
MATRIX_KEY(2, 1, KEY_F5)
MATRIX_KEY(3, 1, KEY_F7)
MATRIX_KEY(4, 1, KEY_F9)
MATRIX_KEY(5, 1, KEY_F3)
MATRIX_KEY(6, 1, KEY_F1)
>;
};
};

9
drivers/auxdisplay/Kconfig
View file

@ -128,4 +128,13 @@ config IMG_ASCII_LCD
development boards such as the MIPS Boston, MIPS Malta & MIPS SEAD3
from Imagination Technologies.
config HT16K33
tristate "Holtek Ht16K33 LED controller with keyscan"
depends on FB && OF && I2C && INPUT
select INPUT_MATRIXKMAP
select FB_BACKLIGHT
help
Say yes here to add support for Holtek HT16K33, RAM mapping 16*8
LED controller driver with keyscan.
endif # AUXDISPLAY

1
drivers/auxdisplay/Makefile
View file

@ -5,3 +5,4 @@
obj-$(CONFIG_KS0108) += ks0108.o
obj-$(CONFIG_CFAG12864B) += cfag12864b.o cfag12864bfb.o
obj-$(CONFIG_IMG_ASCII_LCD) += img-ascii-lcd.o
obj-$(CONFIG_HT16K33) += ht16k33.o

563
drivers/auxdisplay/ht16k33.c Normal file
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@ -0,0 +1,563 @@
/*
* HT16K33 driver
*
* Author: Robin van der Gracht <robin@protonic.nl>
*
* Copyright: (C) 2016 Protonic Holland.
*
* 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.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/i2c.h>
#include <linux/of.h>
#include <linux/fb.h>
#include <linux/slab.h>
#include <linux/backlight.h>
#include <linux/input.h>
#include <linux/input/matrix_keypad.h>
#include <linux/workqueue.h>
#include <linux/mm.h>
/* Registers */
#define REG_SYSTEM_SETUP 0x20
#define REG_SYSTEM_SETUP_OSC_ON BIT(0)
#define REG_DISPLAY_SETUP 0x80
#define REG_DISPLAY_SETUP_ON BIT(0)
#define REG_ROWINT_SET 0xA0
#define REG_ROWINT_SET_INT_EN BIT(0)
#define REG_ROWINT_SET_INT_ACT_HIGH BIT(1)
#define REG_BRIGHTNESS 0xE0
/* Defines */
#define DRIVER_NAME "ht16k33"
#define MIN_BRIGHTNESS 0x1
#define MAX_BRIGHTNESS 0x10
#define HT16K33_MATRIX_LED_MAX_COLS 8
#define HT16K33_MATRIX_LED_MAX_ROWS 16
#define HT16K33_MATRIX_KEYPAD_MAX_COLS 3
#define HT16K33_MATRIX_KEYPAD_MAX_ROWS 12
#define BYTES_PER_ROW (HT16K33_MATRIX_LED_MAX_ROWS / 8)
#define HT16K33_FB_SIZE (HT16K33_MATRIX_LED_MAX_COLS * BYTES_PER_ROW)
struct ht16k33_keypad {
struct input_dev *dev;
spinlock_t lock;
struct delayed_work work;
uint32_t cols;
uint32_t rows;
uint32_t row_shift;
uint32_t debounce_ms;
uint16_t last_key_state[HT16K33_MATRIX_KEYPAD_MAX_COLS];
};
struct ht16k33_fbdev {
struct fb_info *info;
uint32_t refresh_rate;
uint8_t *buffer;
uint8_t *cache;
struct delayed_work work;
};
struct ht16k33_priv {
struct i2c_client *client;
struct ht16k33_keypad keypad;
struct ht16k33_fbdev fbdev;
struct workqueue_struct *workqueue;
};
static struct fb_fix_screeninfo ht16k33_fb_fix = {
.id = DRIVER_NAME,
.type = FB_TYPE_PACKED_PIXELS,
.visual = FB_VISUAL_MONO10,
.xpanstep = 0,
.ypanstep = 0,
.ywrapstep = 0,
.line_length = HT16K33_MATRIX_LED_MAX_ROWS,
.accel = FB_ACCEL_NONE,
};
static struct fb_var_screeninfo ht16k33_fb_var = {
.xres = HT16K33_MATRIX_LED_MAX_ROWS,
.yres = HT16K33_MATRIX_LED_MAX_COLS,
.xres_virtual = HT16K33_MATRIX_LED_MAX_ROWS,
.yres_virtual = HT16K33_MATRIX_LED_MAX_COLS,
.bits_per_pixel = 1,
.red = { 0, 1, 0 },
.green = { 0, 1, 0 },
.blue = { 0, 1, 0 },
.left_margin = 0,
.right_margin = 0,
.upper_margin = 0,
.lower_margin = 0,
.vmode = FB_VMODE_NONINTERLACED,
};
static int ht16k33_display_on(struct ht16k33_priv *priv)
{
uint8_t data = REG_DISPLAY_SETUP | REG_DISPLAY_SETUP_ON;
return i2c_smbus_write_byte(priv->client, data);
}
static int ht16k33_display_off(struct ht16k33_priv *priv)
{
return i2c_smbus_write_byte(priv->client, REG_DISPLAY_SETUP);
}
static void ht16k33_fb_queue(struct ht16k33_priv *priv)
{
struct ht16k33_fbdev *fbdev = &priv->fbdev;
queue_delayed_work(priv->workqueue, &fbdev->work,
msecs_to_jiffies(HZ / fbdev->refresh_rate));
}
static void ht16k33_keypad_queue(struct ht16k33_priv *priv)
{
struct ht16k33_keypad *keypad = &priv->keypad;
queue_delayed_work(priv->workqueue, &keypad->work,
msecs_to_jiffies(keypad->debounce_ms));
}
/*
* This gets the fb data from cache and copies it to ht16k33 display RAM
*/
static void ht16k33_fb_update(struct work_struct *work)
{
struct ht16k33_fbdev *fbdev =
container_of(work, struct ht16k33_fbdev, work.work);
struct ht16k33_priv *priv =
container_of(fbdev, struct ht16k33_priv, fbdev);
uint8_t *p1, *p2;
int len, pos = 0, first = -1;
p1 = fbdev->cache;
p2 = fbdev->buffer;
/* Search for the first byte with changes */
while (pos < HT16K33_FB_SIZE && first < 0) {
if (*(p1++) - *(p2++))
first = pos;
pos++;
}
/* No changes found */
if (first < 0)
goto requeue;
len = HT16K33_FB_SIZE - first;
p1 = fbdev->cache + HT16K33_FB_SIZE - 1;
p2 = fbdev->buffer + HT16K33_FB_SIZE - 1;
/* Determine i2c transfer length */
while (len > 1) {
if (*(p1--) - *(p2--))
break;
len--;
}
p1 = fbdev->cache + first;
p2 = fbdev->buffer + first;
if (!i2c_smbus_write_i2c_block_data(priv->client, first, len, p2))
memcpy(p1, p2, len);
requeue:
ht16k33_fb_queue(priv);
}
static int ht16k33_keypad_start(struct input_dev *dev)
{
struct ht16k33_priv *priv = input_get_drvdata(dev);
struct ht16k33_keypad *keypad = &priv->keypad;
/*
* Schedule an immediate key scan to capture current key state;
* columns will be activated and IRQs be enabled after the scan.
*/
queue_delayed_work(priv->workqueue, &keypad->work, 0);
return 0;
}
static void ht16k33_keypad_stop(struct input_dev *dev)
{
struct ht16k33_priv *priv = input_get_drvdata(dev);
struct ht16k33_keypad *keypad = &priv->keypad;
cancel_delayed_work(&keypad->work);
/*
* ht16k33_keypad_scan() will leave IRQs enabled;
* we should disable them now.
*/
disable_irq_nosync(priv->client->irq);
}
static int ht16k33_initialize(struct ht16k33_priv *priv)
{
uint8_t byte;
int err;
uint8_t data[HT16K33_MATRIX_LED_MAX_COLS * 2];
/* Clear RAM (8 * 16 bits) */
memset(data, 0, sizeof(data));
err = i2c_smbus_write_block_data(priv->client, 0, sizeof(data), data);
if (err)
return err;
/* Turn on internal oscillator */
byte = REG_SYSTEM_SETUP_OSC_ON | REG_SYSTEM_SETUP;
err = i2c_smbus_write_byte(priv->client, byte);
if (err)
return err;
/* Configure INT pin */
byte = REG_ROWINT_SET | REG_ROWINT_SET_INT_ACT_HIGH;
if (priv->client->irq > 0)
byte |= REG_ROWINT_SET_INT_EN;
return i2c_smbus_write_byte(priv->client, byte);
}
/*
* This gets the keys from keypad and reports it to input subsystem
*/
static void ht16k33_keypad_scan(struct work_struct *work)
{
struct ht16k33_keypad *keypad =
container_of(work, struct ht16k33_keypad, work.work);
struct ht16k33_priv *priv =
container_of(keypad, struct ht16k33_priv, keypad);
const unsigned short *keycodes = keypad->dev->keycode;
uint16_t bits_changed, new_state[HT16K33_MATRIX_KEYPAD_MAX_COLS];
uint8_t data[HT16K33_MATRIX_KEYPAD_MAX_COLS * 2];
int row, col, code;
bool reschedule = false;
if (i2c_smbus_read_i2c_block_data(priv->client, 0x40, 6, data) != 6) {
dev_err(&priv->client->dev, "Failed to read key data\n");
goto end;
}
for (col = 0; col < keypad->cols; col++) {
new_state[col] = (data[col * 2 + 1] << 8) | data[col * 2];
if (new_state[col])
reschedule = true;
bits_changed = keypad->last_key_state[col] ^ new_state[col];
while (bits_changed) {
row = ffs(bits_changed) - 1;
code = MATRIX_SCAN_CODE(row, col, keypad->row_shift);
input_event(keypad->dev, EV_MSC, MSC_SCAN, code);
input_report_key(keypad->dev, keycodes[code],
new_state[col] & BIT(row));
bits_changed &= ~BIT(row);
}
}
input_sync(keypad->dev);
memcpy(keypad->last_key_state, new_state, sizeof(new_state));
end:
if (reschedule)
ht16k33_keypad_queue(priv);
else
enable_irq(priv->client->irq);
}
static irqreturn_t ht16k33_irq_thread(int irq, void *dev)
{
struct ht16k33_priv *priv = dev;
disable_irq_nosync(priv->client->irq);
ht16k33_keypad_queue(priv);
return IRQ_HANDLED;
}
static int ht16k33_bl_update_status(struct backlight_device *bl)
{
int brightness = bl->props.brightness;
struct ht16k33_priv *priv = bl_get_data(bl);
if (bl->props.power != FB_BLANK_UNBLANK ||
bl->props.fb_blank != FB_BLANK_UNBLANK ||
bl->props.state & BL_CORE_FBBLANK || brightness == 0) {
return ht16k33_display_off(priv);
}
ht16k33_display_on(priv);
return i2c_smbus_write_byte(priv->client,
REG_BRIGHTNESS | (brightness - 1));
}
static int ht16k33_bl_check_fb(struct backlight_device *bl, struct fb_info *fi)
{
struct ht16k33_priv *priv = bl_get_data(bl);
return (fi == NULL) || (fi->par == priv);
}
static const struct backlight_ops ht16k33_bl_ops = {
.update_status = ht16k33_bl_update_status,
.check_fb = ht16k33_bl_check_fb,
};
static int ht16k33_mmap(struct fb_info *info, struct vm_area_struct *vma)
{
struct ht16k33_priv *priv = info->par;
return vm_insert_page(vma, vma->vm_start,
virt_to_page(priv->fbdev.buffer));
}
static struct fb_ops ht16k33_fb_ops = {
.owner = THIS_MODULE,
.fb_read = fb_sys_read,
.fb_write = fb_sys_write,
.fb_fillrect = sys_fillrect,
.fb_copyarea = sys_copyarea,
.fb_imageblit = sys_imageblit,
.fb_mmap = ht16k33_mmap,
};
static int ht16k33_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
int err;
uint32_t rows, cols, dft_brightness;
struct backlight_device *bl;
struct backlight_properties bl_props;
struct ht16k33_priv *priv;
struct ht16k33_keypad *keypad;
struct ht16k33_fbdev *fbdev;
struct device_node *node = client->dev.of_node;
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
dev_err(&client->dev, "i2c_check_functionality error\n");
return -EIO;
}
if (client->irq <= 0) {
dev_err(&client->dev, "No IRQ specified\n");
return -EINVAL;
}
priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->client = client;
i2c_set_clientdata(client, priv);
fbdev = &priv->fbdev;
keypad = &priv->keypad;
priv->workqueue = create_singlethread_workqueue(DRIVER_NAME "-wq");
if (priv->workqueue == NULL)
return -ENOMEM;
err = ht16k33_initialize(priv);
if (err)
goto err_destroy_wq;
/* Framebuffer (2 bytes per column) */
BUILD_BUG_ON(PAGE_SIZE < HT16K33_FB_SIZE);
fbdev->buffer = (unsigned char *) get_zeroed_page(GFP_KERNEL);
if (!fbdev->buffer) {
err = -ENOMEM;
goto err_free_fbdev;
}
fbdev->cache = devm_kmalloc(&client->dev, HT16K33_FB_SIZE, GFP_KERNEL);
if (!fbdev->cache) {
err = -ENOMEM;
goto err_fbdev_buffer;
}
fbdev->info = framebuffer_alloc(0, &client->dev);
if (!fbdev->info) {
err = -ENOMEM;
goto err_fbdev_buffer;
}
err = of_property_read_u32(node, "refresh-rate-hz",
&fbdev->refresh_rate);
if (err) {
dev_err(&client->dev, "refresh rate not specified\n");
goto err_fbdev_info;
}
fb_bl_default_curve(fbdev->info, 0, MIN_BRIGHTNESS, MAX_BRIGHTNESS);
INIT_DELAYED_WORK(&fbdev->work, ht16k33_fb_update);
fbdev->info->fbops = &ht16k33_fb_ops;
fbdev->info->screen_base = (char __iomem *) fbdev->buffer;
fbdev->info->screen_size = HT16K33_FB_SIZE;
fbdev->info->fix = ht16k33_fb_fix;
fbdev->info->var = ht16k33_fb_var;
fbdev->info->pseudo_palette = NULL;
fbdev->info->flags = FBINFO_FLAG_DEFAULT;
fbdev->info->par = priv;
err = register_framebuffer(fbdev->info);
if (err)
goto err_fbdev_info;
/* Keypad */
keypad->dev = devm_input_allocate_device(&client->dev);
if (!keypad->dev) {
err = -ENOMEM;
goto err_fbdev_unregister;
}
keypad->dev->name = DRIVER_NAME"-keypad";
keypad->dev->id.bustype = BUS_I2C;
keypad->dev->open = ht16k33_keypad_start;
keypad->dev->close = ht16k33_keypad_stop;
if (!of_get_property(node, "linux,no-autorepeat", NULL))
__set_bit(EV_REP, keypad->dev->evbit);
err = of_property_read_u32(node, "debounce-delay-ms",
&keypad->debounce_ms);
if (err) {
dev_err(&client->dev, "key debounce delay not specified\n");
goto err_fbdev_unregister;
}
err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
ht16k33_irq_thread,
IRQF_TRIGGER_RISING | IRQF_ONESHOT,
DRIVER_NAME, priv);
if (err) {
dev_err(&client->dev, "irq request failed %d, error %d\n",
client->irq, err);
goto err_fbdev_unregister;
}
disable_irq_nosync(client->irq);
rows = HT16K33_MATRIX_KEYPAD_MAX_ROWS;
cols = HT16K33_MATRIX_KEYPAD_MAX_COLS;
err = matrix_keypad_parse_of_params(&client->dev, &rows, &cols);
if (err)
goto err_fbdev_unregister;
err = matrix_keypad_build_keymap(NULL, NULL, rows, cols, NULL,
keypad->dev);
if (err) {
dev_err(&client->dev, "failed to build keymap\n");
goto err_fbdev_unregister;
}
input_set_drvdata(keypad->dev, priv);
keypad->rows = rows;
keypad->cols = cols;
keypad->row_shift = get_count_order(cols);
INIT_DELAYED_WORK(&keypad->work, ht16k33_keypad_scan);
err = input_register_device(keypad->dev);
if (err)
goto err_fbdev_unregister;
/* Backlight */
memset(&bl_props, 0, sizeof(struct backlight_properties));
bl_props.type = BACKLIGHT_RAW;
bl_props.max_brightness = MAX_BRIGHTNESS;
bl = devm_backlight_device_register(&client->dev, DRIVER_NAME"-bl",
&client->dev, priv,
&ht16k33_bl_ops, &bl_props);
if (IS_ERR(bl)) {
dev_err(&client->dev, "failed to register backlight\n");
err = PTR_ERR(bl);
goto err_keypad_unregister;
}
err = of_property_read_u32(node, "default-brightness-level",
&dft_brightness);
if (err) {
dft_brightness = MAX_BRIGHTNESS;
} else if (dft_brightness > MAX_BRIGHTNESS) {
dev_warn(&client->dev,
"invalid default brightness level: %u, using %u\n",
dft_brightness, MAX_BRIGHTNESS);
dft_brightness = MAX_BRIGHTNESS;
}
bl->props.brightness = dft_brightness;
ht16k33_bl_update_status(bl);
ht16k33_fb_queue(priv);
return 0;
err_keypad_unregister:
input_unregister_device(keypad->dev);
err_fbdev_unregister:
unregister_framebuffer(fbdev->info);
err_fbdev_info:
framebuffer_release(fbdev->info);
err_fbdev_buffer:
free_page((unsigned long) fbdev->buffer);
err_free_fbdev:
kfree(fbdev);
err_destroy_wq:
destroy_workqueue(priv->workqueue);
return err;
}
static int ht16k33_remove(struct i2c_client *client)
{
struct ht16k33_priv *priv = i2c_get_clientdata(client);
struct ht16k33_keypad *keypad = &priv->keypad;
struct ht16k33_fbdev *fbdev = &priv->fbdev;
ht16k33_keypad_stop(keypad->dev);
cancel_delayed_work(&fbdev->work);
unregister_framebuffer(fbdev->info);
framebuffer_release(fbdev->info);
free_page((unsigned long) fbdev->buffer);
destroy_workqueue(priv->workqueue);
return 0;
}
static const struct i2c_device_id ht16k33_i2c_match[] = {
{ "ht16k33", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, ht16k33_i2c_match);
static const struct of_device_id ht16k33_of_match[] = {
{ .compatible = "holtek,ht16k33", },
{ }
};
MODULE_DEVICE_TABLE(of, ht16k33_of_match);
static struct i2c_driver ht16k33_driver = {
.probe = ht16k33_probe,
.remove = ht16k33_remove,
.driver = {
.name = DRIVER_NAME,
.of_match_table = of_match_ptr(ht16k33_of_match),
},
.id_table = ht16k33_i2c_match,
};
module_i2c_driver(ht16k33_driver);
MODULE_DESCRIPTION("Holtek HT16K33 driver");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Robin van der Gracht <robin@protonic.nl>");