// SPDX-License-Identifier: GPL-2.0
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/gpio.h>
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#include <linux/spi/spi.h>
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#include <linux/delay.h>
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#include "fbtft.h"
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#define DRVNAME "fb_ssd1351"
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#define WIDTH 128
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#define HEIGHT 128
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#define GAMMA_NUM 1
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#define GAMMA_LEN 63
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#define DEFAULT_GAMMA "0 2 2 2 2 2 2 2 " \
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"2 2 2 2 2 2 2 2 " \
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"2 2 2 2 2 2 2 2 " \
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"2 2 2 2 2 2 2 2 " \
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"2 2 2 2 2 2 2 2 " \
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"2 2 2 2 2 2 2 2 " \
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"2 2 2 2 2 2 2 2 " \
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"2 2 2 2 2 2 2" \
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static void register_onboard_backlight(struct fbtft_par *par);
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static int init_display(struct fbtft_par *par)
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{
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if (par->pdata &&
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par->pdata->display.backlight == FBTFT_ONBOARD_BACKLIGHT) {
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/* module uses onboard GPIO for panel power */
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par->fbtftops.register_backlight = register_onboard_backlight;
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}
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par->fbtftops.reset(par);
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write_reg(par, 0xfd, 0x12); /* Command Lock */
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write_reg(par, 0xfd, 0xb1); /* Command Lock */
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write_reg(par, 0xae); /* Display Off */
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write_reg(par, 0xb3, 0xf1); /* Front Clock Div */
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write_reg(par, 0xca, 0x7f); /* Set Mux Ratio */
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write_reg(par, 0x15, 0x00, 0x7f); /* Set Column Address */
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write_reg(par, 0x75, 0x00, 0x7f); /* Set Row Address */
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write_reg(par, 0xa1, 0x00); /* Set Display Start Line */
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write_reg(par, 0xa2, 0x00); /* Set Display Offset */
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write_reg(par, 0xb5, 0x00); /* Set GPIO */
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write_reg(par, 0xab, 0x01); /* Set Function Selection */
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write_reg(par, 0xb1, 0x32); /* Set Phase Length */
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write_reg(par, 0xb4, 0xa0, 0xb5, 0x55); /* Set Segment Low Voltage */
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write_reg(par, 0xbb, 0x17); /* Set Precharge Voltage */
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write_reg(par, 0xbe, 0x05); /* Set VComH Voltage */
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write_reg(par, 0xc1, 0xc8, 0x80, 0xc8); /* Set Contrast */
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write_reg(par, 0xc7, 0x0f); /* Set Master Contrast */
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write_reg(par, 0xb6, 0x01); /* Set Second Precharge Period */
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write_reg(par, 0xa6); /* Set Display Mode Reset */
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write_reg(par, 0xaf); /* Set Sleep Mode Display On */
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return 0;
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}
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static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye)
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{
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write_reg(par, 0x15, xs, xe);
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write_reg(par, 0x75, ys, ye);
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write_reg(par, 0x5c);
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}
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static int set_var(struct fbtft_par *par)
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{
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unsigned int remap;
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if (par->fbtftops.init_display != init_display) {
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/* don't risk messing up register A0h */
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fbtft_par_dbg(DEBUG_INIT_DISPLAY, par,
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"%s: skipping since custom init_display() is used\n",
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__func__);
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return 0;
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}
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remap = 0x60 | (par->bgr << 2); /* Set Colour Depth */
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switch (par->info->var.rotate) {
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case 0:
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write_reg(par, 0xA0, remap | 0x00 | 1 << 4);
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break;
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case 270:
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write_reg(par, 0xA0, remap | 0x03 | 1 << 4);
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break;
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case 180:
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write_reg(par, 0xA0, remap | 0x02);
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break;
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case 90:
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write_reg(par, 0xA0, remap | 0x01);
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break;
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}
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return 0;
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}
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/*
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* Grayscale Lookup Table
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* GS1 - GS63
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* The driver Gamma curve contains the relative values between the entries
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* in the Lookup table.
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*
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* From datasheet:
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* 8.8 Gray Scale Decoder
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*
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* there are total 180 Gamma Settings (Setting 0 to Setting 180)
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* available for the Gray Scale table.
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*
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* The gray scale is defined in incremental way, with reference
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* to the length of previous table entry:
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* Setting of GS1 has to be >= 0
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* Setting of GS2 has to be > Setting of GS1 +1
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* Setting of GS3 has to be > Setting of GS2 +1
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* :
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* Setting of GS63 has to be > Setting of GS62 +1
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*
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*/
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static int set_gamma(struct fbtft_par *par, u32 *curves)
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{
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unsigned long tmp[GAMMA_NUM * GAMMA_LEN];
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int i, acc = 0;
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for (i = 0; i < 63; i++) {
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if (i > 0 && curves[i] < 2) {
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dev_err(par->info->device,
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"Illegal value in Grayscale Lookup Table at index %d : %d. Must be greater than 1\n",
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i, curves[i]);
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return -EINVAL;
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}
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acc += curves[i];
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tmp[i] = acc;
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if (acc > 180) {
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dev_err(par->info->device,
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"Illegal value(s) in Grayscale Lookup Table. At index=%d : %d, the accumulated value has exceeded 180\n",
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i, acc);
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return -EINVAL;
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}
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}
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write_reg(par, 0xB8,
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tmp[0], tmp[1], tmp[2], tmp[3],
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tmp[4], tmp[5], tmp[6], tmp[7],
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tmp[8], tmp[9], tmp[10], tmp[11],
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tmp[12], tmp[13], tmp[14], tmp[15],
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tmp[16], tmp[17], tmp[18], tmp[19],
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tmp[20], tmp[21], tmp[22], tmp[23],
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tmp[24], tmp[25], tmp[26], tmp[27],
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tmp[28], tmp[29], tmp[30], tmp[31],
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tmp[32], tmp[33], tmp[34], tmp[35],
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tmp[36], tmp[37], tmp[38], tmp[39],
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tmp[40], tmp[41], tmp[42], tmp[43],
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tmp[44], tmp[45], tmp[46], tmp[47],
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tmp[48], tmp[49], tmp[50], tmp[51],
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tmp[52], tmp[53], tmp[54], tmp[55],
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tmp[56], tmp[57], tmp[58], tmp[59],
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tmp[60], tmp[61], tmp[62]);
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return 0;
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}
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static int blank(struct fbtft_par *par, bool on)
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{
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fbtft_par_dbg(DEBUG_BLANK, par, "(%s=%s)\n",
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__func__, on ? "true" : "false");
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if (on)
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write_reg(par, 0xAE);
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else
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write_reg(par, 0xAF);
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return 0;
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}
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static struct fbtft_display display = {
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.regwidth = 8,
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.width = WIDTH,
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.height = HEIGHT,
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.gamma_num = GAMMA_NUM,
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.gamma_len = GAMMA_LEN,
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.gamma = DEFAULT_GAMMA,
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.fbtftops = {
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.init_display = init_display,
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.set_addr_win = set_addr_win,
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.set_var = set_var,
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.set_gamma = set_gamma,
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.blank = blank,
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},
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};
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#ifdef CONFIG_FB_BACKLIGHT
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static int update_onboard_backlight(struct backlight_device *bd)
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{
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struct fbtft_par *par = bl_get_data(bd);
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bool on;
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fbtft_par_dbg(DEBUG_BACKLIGHT, par,
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"%s: power=%d, fb_blank=%d\n",
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__func__, bd->props.power, bd->props.fb_blank);
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on = (bd->props.power == FB_BLANK_UNBLANK) &&
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(bd->props.fb_blank == FB_BLANK_UNBLANK);
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/* Onboard backlight connected to GPIO0 on SSD1351, GPIO1 unused */
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write_reg(par, 0xB5, on ? 0x03 : 0x02);
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return 0;
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}
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static const struct backlight_ops bl_ops = {
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.update_status = update_onboard_backlight,
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};
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static void register_onboard_backlight(struct fbtft_par *par)
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{
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struct backlight_device *bd;
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struct backlight_properties bl_props = { 0, };
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bl_props.type = BACKLIGHT_RAW;
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bl_props.power = FB_BLANK_POWERDOWN;
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bd = backlight_device_register(dev_driver_string(par->info->device),
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par->info->device, par, &bl_ops,
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&bl_props);
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if (IS_ERR(bd)) {
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dev_err(par->info->device,
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"cannot register backlight device (%ld)\n",
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PTR_ERR(bd));
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return;
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}
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par->info->bl_dev = bd;
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if (!par->fbtftops.unregister_backlight)
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par->fbtftops.unregister_backlight = fbtft_unregister_backlight;
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}
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#else
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static void register_onboard_backlight(struct fbtft_par *par) { };
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#endif
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FBTFT_REGISTER_DRIVER(DRVNAME, "solomon,ssd1351", &display);
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MODULE_ALIAS("spi:" DRVNAME);
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MODULE_ALIAS("platform:" DRVNAME);
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MODULE_ALIAS("spi:ssd1351");
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MODULE_ALIAS("platform:ssd1351");
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MODULE_DESCRIPTION("SSD1351 OLED Driver");
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MODULE_AUTHOR("James Davies");
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MODULE_LICENSE("GPL");
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