linux/drivers/auxdisplay/ht16k33.c
Dmitry Torokhov 8fa8bea728 auxdisplay: ht16k33: remove private workqueue
There is no need for the driver to use private workqueue, standard system
workqueue should suffice as they are going to use the same worker pool
anyway.

Acked-by: Robin van der Gracht <robin@protonic.nl>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-10 15:57:28 +01:00

544 lines
13 KiB
C

/*
* 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 i2c_client *client;
struct input_dev *dev;
uint32_t cols;
uint32_t rows;
uint32_t row_shift;
uint32_t debounce_ms;
uint16_t last_key_state[HT16K33_MATRIX_KEYPAD_MAX_COLS];
wait_queue_head_t wait;
bool stopped;
};
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;
};
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;
schedule_delayed_work(&fbdev->work,
msecs_to_jiffies(HZ / fbdev->refresh_rate));
}
/*
* 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_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);
}
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,
};
/*
* This gets the keys from keypad and reports it to input subsystem.
* Returns true if a key is pressed.
*/
static bool ht16k33_keypad_scan(struct ht16k33_keypad *keypad)
{
const unsigned short *keycodes = keypad->dev->keycode;
u16 new_state[HT16K33_MATRIX_KEYPAD_MAX_COLS];
u8 data[HT16K33_MATRIX_KEYPAD_MAX_COLS * 2];
unsigned long bits_changed;
int row, col, code;
bool pressed = false;
if (i2c_smbus_read_i2c_block_data(keypad->client, 0x40, 6, data) != 6) {
dev_err(&keypad->client->dev, "Failed to read key data\n");
return false;
}
for (col = 0; col < keypad->cols; col++) {
new_state[col] = (data[col * 2 + 1] << 8) | data[col * 2];
if (new_state[col])
pressed = true;
bits_changed = keypad->last_key_state[col] ^ new_state[col];
for_each_set_bit(row, &bits_changed, BITS_PER_LONG) {
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));
}
}
input_sync(keypad->dev);
memcpy(keypad->last_key_state, new_state, sizeof(new_state));
return pressed;
}
static irqreturn_t ht16k33_keypad_irq_thread(int irq, void *dev)
{
struct ht16k33_keypad *keypad = dev;
do {
wait_event_timeout(keypad->wait, keypad->stopped,
msecs_to_jiffies(keypad->debounce_ms));
if (keypad->stopped)
break;
} while (ht16k33_keypad_scan(keypad));
return IRQ_HANDLED;
}
static int ht16k33_keypad_start(struct input_dev *dev)
{
struct ht16k33_keypad *keypad = input_get_drvdata(dev);
keypad->stopped = false;
mb();
enable_irq(keypad->client->irq);
return 0;
}
static void ht16k33_keypad_stop(struct input_dev *dev)
{
struct ht16k33_keypad *keypad = input_get_drvdata(dev);
keypad->stopped = true;
mb();
wake_up(&keypad->wait);
disable_irq(keypad->client->irq);
}
static int ht16k33_keypad_probe(struct i2c_client *client,
struct ht16k33_keypad *keypad)
{
struct device_node *node = client->dev.of_node;
u32 rows = HT16K33_MATRIX_KEYPAD_MAX_ROWS;
u32 cols = HT16K33_MATRIX_KEYPAD_MAX_COLS;
int err;
keypad->client = client;
init_waitqueue_head(&keypad->wait);
keypad->dev = devm_input_allocate_device(&client->dev);
if (!keypad->dev)
return -ENOMEM;
input_set_drvdata(keypad->dev, keypad);
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");
return err;
}
err = matrix_keypad_parse_of_params(&client->dev, &rows, &cols);
if (err)
return err;
keypad->rows = rows;
keypad->cols = cols;
keypad->row_shift = get_count_order(cols);
err = matrix_keypad_build_keymap(NULL, NULL, rows, cols, NULL,
keypad->dev);
if (err) {
dev_err(&client->dev, "failed to build keymap\n");
return err;
}
err = devm_request_threaded_irq(&client->dev, client->irq,
NULL, ht16k33_keypad_irq_thread,
IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
DRIVER_NAME, keypad);
if (err) {
dev_err(&client->dev, "irq request failed %d, error %d\n",
client->irq, err);
return err;
}
ht16k33_keypad_stop(keypad->dev);
err = input_register_device(keypad->dev);
if (err)
return err;
return 0;
}
static int ht16k33_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
int err;
uint32_t dft_brightness;
struct backlight_device *bl;
struct backlight_properties bl_props;
struct ht16k33_priv *priv;
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;
err = ht16k33_initialize(priv);
if (err)
return err;
/* 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)
return -ENOMEM;
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;
err = ht16k33_keypad_probe(client, &priv->keypad);
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_fbdev_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_fbdev_unregister:
unregister_framebuffer(fbdev->info);
err_fbdev_info:
framebuffer_release(fbdev->info);
err_fbdev_buffer:
free_page((unsigned long) fbdev->buffer);
return err;
}
static int ht16k33_remove(struct i2c_client *client)
{
struct ht16k33_priv *priv = i2c_get_clientdata(client);
struct ht16k33_fbdev *fbdev = &priv->fbdev;
cancel_delayed_work(&fbdev->work);
unregister_framebuffer(fbdev->info);
framebuffer_release(fbdev->info);
free_page((unsigned long) fbdev->buffer);
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>");