forked from Minki/linux
a180d023ec
The static structures ht16k33_fb_fix and ht16k33_fb_var, of types fb_fix_screeninfo and fb_var_screeninfo respectively, are not used except to be copied into other variables. Hence make both of them constant to prevent unintended modification. Issue found with Coccinelle. Acked-by: Robin van der Gracht <robin@protonic.nl> Signed-off-by: Nishka Dasgupta <nishkadg.linux@gmail.com> Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
546 lines
13 KiB
C
546 lines
13 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* HT16K33 driver
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*
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* Author: Robin van der Gracht <robin@protonic.nl>
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*
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* Copyright: (C) 2016 Protonic Holland.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/interrupt.h>
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#include <linux/i2c.h>
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#include <linux/of.h>
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#include <linux/fb.h>
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#include <linux/slab.h>
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#include <linux/backlight.h>
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#include <linux/input.h>
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#include <linux/input/matrix_keypad.h>
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#include <linux/workqueue.h>
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#include <linux/mm.h>
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/* Registers */
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#define REG_SYSTEM_SETUP 0x20
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#define REG_SYSTEM_SETUP_OSC_ON BIT(0)
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#define REG_DISPLAY_SETUP 0x80
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#define REG_DISPLAY_SETUP_ON BIT(0)
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#define REG_ROWINT_SET 0xA0
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#define REG_ROWINT_SET_INT_EN BIT(0)
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#define REG_ROWINT_SET_INT_ACT_HIGH BIT(1)
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#define REG_BRIGHTNESS 0xE0
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/* Defines */
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#define DRIVER_NAME "ht16k33"
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#define MIN_BRIGHTNESS 0x1
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#define MAX_BRIGHTNESS 0x10
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#define HT16K33_MATRIX_LED_MAX_COLS 8
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#define HT16K33_MATRIX_LED_MAX_ROWS 16
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#define HT16K33_MATRIX_KEYPAD_MAX_COLS 3
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#define HT16K33_MATRIX_KEYPAD_MAX_ROWS 12
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#define BYTES_PER_ROW (HT16K33_MATRIX_LED_MAX_ROWS / 8)
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#define HT16K33_FB_SIZE (HT16K33_MATRIX_LED_MAX_COLS * BYTES_PER_ROW)
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struct ht16k33_keypad {
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struct i2c_client *client;
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struct input_dev *dev;
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uint32_t cols;
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uint32_t rows;
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uint32_t row_shift;
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uint32_t debounce_ms;
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uint16_t last_key_state[HT16K33_MATRIX_KEYPAD_MAX_COLS];
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wait_queue_head_t wait;
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bool stopped;
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};
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struct ht16k33_fbdev {
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struct fb_info *info;
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uint32_t refresh_rate;
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uint8_t *buffer;
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uint8_t *cache;
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struct delayed_work work;
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};
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struct ht16k33_priv {
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struct i2c_client *client;
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struct ht16k33_keypad keypad;
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struct ht16k33_fbdev fbdev;
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};
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static const struct fb_fix_screeninfo ht16k33_fb_fix = {
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.id = DRIVER_NAME,
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.type = FB_TYPE_PACKED_PIXELS,
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.visual = FB_VISUAL_MONO10,
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.xpanstep = 0,
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.ypanstep = 0,
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.ywrapstep = 0,
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.line_length = HT16K33_MATRIX_LED_MAX_ROWS,
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.accel = FB_ACCEL_NONE,
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};
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static const struct fb_var_screeninfo ht16k33_fb_var = {
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.xres = HT16K33_MATRIX_LED_MAX_ROWS,
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.yres = HT16K33_MATRIX_LED_MAX_COLS,
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.xres_virtual = HT16K33_MATRIX_LED_MAX_ROWS,
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.yres_virtual = HT16K33_MATRIX_LED_MAX_COLS,
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.bits_per_pixel = 1,
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.red = { 0, 1, 0 },
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.green = { 0, 1, 0 },
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.blue = { 0, 1, 0 },
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.left_margin = 0,
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.right_margin = 0,
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.upper_margin = 0,
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.lower_margin = 0,
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.vmode = FB_VMODE_NONINTERLACED,
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};
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static int ht16k33_display_on(struct ht16k33_priv *priv)
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{
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uint8_t data = REG_DISPLAY_SETUP | REG_DISPLAY_SETUP_ON;
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return i2c_smbus_write_byte(priv->client, data);
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}
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static int ht16k33_display_off(struct ht16k33_priv *priv)
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{
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return i2c_smbus_write_byte(priv->client, REG_DISPLAY_SETUP);
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}
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static void ht16k33_fb_queue(struct ht16k33_priv *priv)
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{
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struct ht16k33_fbdev *fbdev = &priv->fbdev;
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schedule_delayed_work(&fbdev->work,
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msecs_to_jiffies(HZ / fbdev->refresh_rate));
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}
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/*
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* This gets the fb data from cache and copies it to ht16k33 display RAM
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*/
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static void ht16k33_fb_update(struct work_struct *work)
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{
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struct ht16k33_fbdev *fbdev =
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container_of(work, struct ht16k33_fbdev, work.work);
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struct ht16k33_priv *priv =
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container_of(fbdev, struct ht16k33_priv, fbdev);
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uint8_t *p1, *p2;
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int len, pos = 0, first = -1;
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p1 = fbdev->cache;
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p2 = fbdev->buffer;
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/* Search for the first byte with changes */
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while (pos < HT16K33_FB_SIZE && first < 0) {
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if (*(p1++) - *(p2++))
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first = pos;
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pos++;
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}
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/* No changes found */
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if (first < 0)
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goto requeue;
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len = HT16K33_FB_SIZE - first;
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p1 = fbdev->cache + HT16K33_FB_SIZE - 1;
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p2 = fbdev->buffer + HT16K33_FB_SIZE - 1;
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/* Determine i2c transfer length */
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while (len > 1) {
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if (*(p1--) - *(p2--))
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break;
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len--;
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}
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p1 = fbdev->cache + first;
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p2 = fbdev->buffer + first;
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if (!i2c_smbus_write_i2c_block_data(priv->client, first, len, p2))
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memcpy(p1, p2, len);
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requeue:
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ht16k33_fb_queue(priv);
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}
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static int ht16k33_initialize(struct ht16k33_priv *priv)
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{
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uint8_t byte;
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int err;
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uint8_t data[HT16K33_MATRIX_LED_MAX_COLS * 2];
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/* Clear RAM (8 * 16 bits) */
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memset(data, 0, sizeof(data));
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err = i2c_smbus_write_block_data(priv->client, 0, sizeof(data), data);
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if (err)
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return err;
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/* Turn on internal oscillator */
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byte = REG_SYSTEM_SETUP_OSC_ON | REG_SYSTEM_SETUP;
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err = i2c_smbus_write_byte(priv->client, byte);
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if (err)
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return err;
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/* Configure INT pin */
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byte = REG_ROWINT_SET | REG_ROWINT_SET_INT_ACT_HIGH;
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if (priv->client->irq > 0)
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byte |= REG_ROWINT_SET_INT_EN;
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return i2c_smbus_write_byte(priv->client, byte);
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}
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static int ht16k33_bl_update_status(struct backlight_device *bl)
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{
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int brightness = bl->props.brightness;
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struct ht16k33_priv *priv = bl_get_data(bl);
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if (bl->props.power != FB_BLANK_UNBLANK ||
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bl->props.fb_blank != FB_BLANK_UNBLANK ||
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bl->props.state & BL_CORE_FBBLANK || brightness == 0) {
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return ht16k33_display_off(priv);
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}
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ht16k33_display_on(priv);
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return i2c_smbus_write_byte(priv->client,
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REG_BRIGHTNESS | (brightness - 1));
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}
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static int ht16k33_bl_check_fb(struct backlight_device *bl, struct fb_info *fi)
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{
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struct ht16k33_priv *priv = bl_get_data(bl);
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return (fi == NULL) || (fi->par == priv);
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}
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static const struct backlight_ops ht16k33_bl_ops = {
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.update_status = ht16k33_bl_update_status,
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.check_fb = ht16k33_bl_check_fb,
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};
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static int ht16k33_mmap(struct fb_info *info, struct vm_area_struct *vma)
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{
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struct ht16k33_priv *priv = info->par;
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struct page *pages = virt_to_page(priv->fbdev.buffer);
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return vm_map_pages_zero(vma, &pages, 1);
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}
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static struct fb_ops ht16k33_fb_ops = {
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.owner = THIS_MODULE,
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.fb_read = fb_sys_read,
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.fb_write = fb_sys_write,
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.fb_fillrect = sys_fillrect,
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.fb_copyarea = sys_copyarea,
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.fb_imageblit = sys_imageblit,
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.fb_mmap = ht16k33_mmap,
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};
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/*
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* This gets the keys from keypad and reports it to input subsystem.
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* Returns true if a key is pressed.
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*/
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static bool ht16k33_keypad_scan(struct ht16k33_keypad *keypad)
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{
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const unsigned short *keycodes = keypad->dev->keycode;
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u16 new_state[HT16K33_MATRIX_KEYPAD_MAX_COLS];
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__le16 data[HT16K33_MATRIX_KEYPAD_MAX_COLS];
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unsigned long bits_changed;
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int row, col, code;
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int rc;
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bool pressed = false;
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rc = i2c_smbus_read_i2c_block_data(keypad->client, 0x40,
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sizeof(data), (u8 *)data);
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if (rc != sizeof(data)) {
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dev_err(&keypad->client->dev,
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"Failed to read key data, rc=%d\n", rc);
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return false;
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}
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for (col = 0; col < keypad->cols; col++) {
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new_state[col] = le16_to_cpu(data[col]);
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if (new_state[col])
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pressed = true;
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bits_changed = keypad->last_key_state[col] ^ new_state[col];
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for_each_set_bit(row, &bits_changed, BITS_PER_LONG) {
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code = MATRIX_SCAN_CODE(row, col, keypad->row_shift);
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input_event(keypad->dev, EV_MSC, MSC_SCAN, code);
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input_report_key(keypad->dev, keycodes[code],
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new_state[col] & BIT(row));
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}
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}
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input_sync(keypad->dev);
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memcpy(keypad->last_key_state, new_state, sizeof(u16) * keypad->cols);
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return pressed;
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}
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static irqreturn_t ht16k33_keypad_irq_thread(int irq, void *dev)
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{
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struct ht16k33_keypad *keypad = dev;
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do {
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wait_event_timeout(keypad->wait, keypad->stopped,
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msecs_to_jiffies(keypad->debounce_ms));
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if (keypad->stopped)
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break;
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} while (ht16k33_keypad_scan(keypad));
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return IRQ_HANDLED;
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}
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static int ht16k33_keypad_start(struct input_dev *dev)
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{
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struct ht16k33_keypad *keypad = input_get_drvdata(dev);
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keypad->stopped = false;
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mb();
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enable_irq(keypad->client->irq);
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return 0;
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}
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static void ht16k33_keypad_stop(struct input_dev *dev)
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{
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struct ht16k33_keypad *keypad = input_get_drvdata(dev);
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keypad->stopped = true;
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mb();
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wake_up(&keypad->wait);
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disable_irq(keypad->client->irq);
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}
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static int ht16k33_keypad_probe(struct i2c_client *client,
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struct ht16k33_keypad *keypad)
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{
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struct device_node *node = client->dev.of_node;
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u32 rows = HT16K33_MATRIX_KEYPAD_MAX_ROWS;
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u32 cols = HT16K33_MATRIX_KEYPAD_MAX_COLS;
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int err;
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keypad->client = client;
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init_waitqueue_head(&keypad->wait);
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keypad->dev = devm_input_allocate_device(&client->dev);
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if (!keypad->dev)
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return -ENOMEM;
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input_set_drvdata(keypad->dev, keypad);
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keypad->dev->name = DRIVER_NAME"-keypad";
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keypad->dev->id.bustype = BUS_I2C;
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keypad->dev->open = ht16k33_keypad_start;
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keypad->dev->close = ht16k33_keypad_stop;
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if (!of_get_property(node, "linux,no-autorepeat", NULL))
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__set_bit(EV_REP, keypad->dev->evbit);
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err = of_property_read_u32(node, "debounce-delay-ms",
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&keypad->debounce_ms);
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if (err) {
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dev_err(&client->dev, "key debounce delay not specified\n");
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return err;
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}
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err = matrix_keypad_parse_of_params(&client->dev, &rows, &cols);
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if (err)
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return err;
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if (rows > HT16K33_MATRIX_KEYPAD_MAX_ROWS ||
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cols > HT16K33_MATRIX_KEYPAD_MAX_COLS) {
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dev_err(&client->dev, "%u rows or %u cols out of range in DT\n",
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rows, cols);
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return -ERANGE;
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}
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keypad->rows = rows;
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keypad->cols = cols;
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keypad->row_shift = get_count_order(cols);
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err = matrix_keypad_build_keymap(NULL, NULL, rows, cols, NULL,
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keypad->dev);
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if (err) {
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dev_err(&client->dev, "failed to build keymap\n");
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return err;
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}
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err = devm_request_threaded_irq(&client->dev, client->irq,
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NULL, ht16k33_keypad_irq_thread,
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IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
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DRIVER_NAME, keypad);
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if (err) {
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dev_err(&client->dev, "irq request failed %d, error %d\n",
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client->irq, err);
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return err;
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}
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ht16k33_keypad_stop(keypad->dev);
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err = input_register_device(keypad->dev);
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if (err)
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return err;
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return 0;
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}
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static int ht16k33_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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int err;
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uint32_t dft_brightness;
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struct backlight_device *bl;
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struct backlight_properties bl_props;
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struct ht16k33_priv *priv;
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struct ht16k33_fbdev *fbdev;
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struct device_node *node = client->dev.of_node;
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if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
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dev_err(&client->dev, "i2c_check_functionality error\n");
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return -EIO;
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}
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if (client->irq <= 0) {
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dev_err(&client->dev, "No IRQ specified\n");
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return -EINVAL;
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}
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priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
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if (!priv)
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return -ENOMEM;
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priv->client = client;
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i2c_set_clientdata(client, priv);
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fbdev = &priv->fbdev;
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err = ht16k33_initialize(priv);
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if (err)
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return err;
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/* Framebuffer (2 bytes per column) */
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BUILD_BUG_ON(PAGE_SIZE < HT16K33_FB_SIZE);
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fbdev->buffer = (unsigned char *) get_zeroed_page(GFP_KERNEL);
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if (!fbdev->buffer)
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return -ENOMEM;
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fbdev->cache = devm_kmalloc(&client->dev, HT16K33_FB_SIZE, GFP_KERNEL);
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if (!fbdev->cache) {
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err = -ENOMEM;
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goto err_fbdev_buffer;
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}
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fbdev->info = framebuffer_alloc(0, &client->dev);
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if (!fbdev->info) {
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err = -ENOMEM;
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goto err_fbdev_buffer;
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}
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err = of_property_read_u32(node, "refresh-rate-hz",
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&fbdev->refresh_rate);
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if (err) {
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dev_err(&client->dev, "refresh rate not specified\n");
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goto err_fbdev_info;
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}
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fb_bl_default_curve(fbdev->info, 0, MIN_BRIGHTNESS, MAX_BRIGHTNESS);
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INIT_DELAYED_WORK(&fbdev->work, ht16k33_fb_update);
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fbdev->info->fbops = &ht16k33_fb_ops;
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fbdev->info->screen_base = (char __iomem *) fbdev->buffer;
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fbdev->info->screen_size = HT16K33_FB_SIZE;
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fbdev->info->fix = ht16k33_fb_fix;
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fbdev->info->var = ht16k33_fb_var;
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fbdev->info->pseudo_palette = NULL;
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fbdev->info->flags = FBINFO_FLAG_DEFAULT;
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fbdev->info->par = priv;
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err = register_framebuffer(fbdev->info);
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if (err)
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goto err_fbdev_info;
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err = ht16k33_keypad_probe(client, &priv->keypad);
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if (err)
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goto err_fbdev_unregister;
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/* Backlight */
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memset(&bl_props, 0, sizeof(struct backlight_properties));
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bl_props.type = BACKLIGHT_RAW;
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bl_props.max_brightness = MAX_BRIGHTNESS;
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bl = devm_backlight_device_register(&client->dev, DRIVER_NAME"-bl",
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&client->dev, priv,
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&ht16k33_bl_ops, &bl_props);
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if (IS_ERR(bl)) {
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dev_err(&client->dev, "failed to register backlight\n");
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err = PTR_ERR(bl);
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goto err_fbdev_unregister;
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}
|
|
|
|
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_sync(&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>");
|