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542 lines
13 KiB
542 lines
13 KiB
// 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 <[email protected]> |
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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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|
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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, 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 const 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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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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/* Keypad */ |
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if (client->irq > 0) { |
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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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} |
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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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} |
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err = of_property_read_u32(node, "default-brightness-level", |
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&dft_brightness); |
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if (err) { |
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dft_brightness = MAX_BRIGHTNESS; |
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} else if (dft_brightness > MAX_BRIGHTNESS) { |
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dev_warn(&client->dev, |
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"invalid default brightness level: %u, using %u\n", |
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dft_brightness, MAX_BRIGHTNESS); |
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dft_brightness = MAX_BRIGHTNESS; |
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} |
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bl->props.brightness = dft_brightness; |
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ht16k33_bl_update_status(bl); |
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ht16k33_fb_queue(priv); |
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return 0; |
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err_fbdev_unregister: |
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unregister_framebuffer(fbdev->info); |
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err_fbdev_info: |
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framebuffer_release(fbdev->info); |
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err_fbdev_buffer: |
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free_page((unsigned long) fbdev->buffer); |
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return err; |
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} |
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static int ht16k33_remove(struct i2c_client *client) |
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{ |
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struct ht16k33_priv *priv = i2c_get_clientdata(client); |
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struct ht16k33_fbdev *fbdev = &priv->fbdev; |
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cancel_delayed_work_sync(&fbdev->work); |
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unregister_framebuffer(fbdev->info); |
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framebuffer_release(fbdev->info); |
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free_page((unsigned long) fbdev->buffer); |
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return 0; |
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} |
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static const struct i2c_device_id ht16k33_i2c_match[] = { |
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{ "ht16k33", 0 }, |
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{ } |
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}; |
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MODULE_DEVICE_TABLE(i2c, ht16k33_i2c_match); |
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static const struct of_device_id ht16k33_of_match[] = { |
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{ .compatible = "holtek,ht16k33", }, |
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{ } |
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}; |
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MODULE_DEVICE_TABLE(of, ht16k33_of_match); |
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static struct i2c_driver ht16k33_driver = { |
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.probe = ht16k33_probe, |
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.remove = ht16k33_remove, |
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.driver = { |
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.name = DRIVER_NAME, |
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.of_match_table = of_match_ptr(ht16k33_of_match), |
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}, |
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.id_table = ht16k33_i2c_match, |
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}; |
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module_i2c_driver(ht16k33_driver); |
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MODULE_DESCRIPTION("Holtek HT16K33 driver"); |
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MODULE_LICENSE("GPL"); |
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MODULE_AUTHOR("Robin van der Gracht <[email protected]>");
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