path: root/drivers/video/fbdev/ssd1307fb.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Driver for the Solomon SSD1307 OLED controller
 *
 * Copyright 2012 Free Electrons
 */

#include <linux/backlight.h>
#include <linux/delay.h>
#include <linux/fb.h>
#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/property.h>
#include <linux/pwm.h>
#include <linux/spinlock.h>
#include <linux/uaccess.h>
#include <linux/regulator/consumer.h>

#define SSD1307FB_DATA			0x40
#define SSD1307FB_COMMAND		0x80

#define SSD1307FB_SET_ADDRESS_MODE	0x20
#define SSD1307FB_SET_ADDRESS_MODE_HORIZONTAL	(0x00)
#define SSD1307FB_SET_ADDRESS_MODE_VERTICAL	(0x01)
#define SSD1307FB_SET_ADDRESS_MODE_PAGE		(0x02)
#define SSD1307FB_SET_COL_RANGE		0x21
#define SSD1307FB_SET_PAGE_RANGE	0x22
#define SSD1307FB_CONTRAST		0x81
#define SSD1307FB_SET_LOOKUP_TABLE	0x91
#define	SSD1307FB_CHARGE_PUMP		0x8d
#define SSD1307FB_SEG_REMAP_ON		0xa1
#define SSD1307FB_DISPLAY_OFF		0xae
#define SSD1307FB_SET_MULTIPLEX_RATIO	0xa8
#define SSD1307FB_DISPLAY_ON		0xaf
#define SSD1307FB_START_PAGE_ADDRESS	0xb0
#define SSD1307FB_SET_DISPLAY_OFFSET	0xd3
#define	SSD1307FB_SET_CLOCK_FREQ	0xd5
#define	SSD1307FB_SET_AREA_COLOR_MODE	0xd8
#define	SSD1307FB_SET_PRECHARGE_PERIOD	0xd9
#define	SSD1307FB_SET_COM_PINS_CONFIG	0xda
#define	SSD1307FB_SET_VCOMH		0xdb

#define MAX_CONTRAST 255

#define REFRESHRATE 1

static u_int refreshrate = REFRESHRATE;
module_param(refreshrate, uint, 0);

struct ssd1307fb_deviceinfo {
	u32 default_vcomh;
	u32 default_dclk_div;
	u32 default_dclk_frq;
	bool need_pwm;
	bool need_chargepump;
};

struct ssd1307fb_par {
	unsigned area_color_enable : 1;
	unsigned com_invdir : 1;
	unsigned com_lrremap : 1;
	unsigned com_seq : 1;
	unsigned lookup_table_set : 1;
	unsigned low_power : 1;
	unsigned seg_remap : 1;
	u32 com_offset;
	u32 contrast;
	u32 dclk_div;
	u32 dclk_frq;
	const struct ssd1307fb_deviceinfo *device_info;
	struct i2c_client *client;
	u32 height;
	struct fb_info *info;
	/* Pending damage, with exclusive x2/y2, protected by damage_lock. */
	spinlock_t damage_lock;
	bool damage_pending;
	u32 damage_x1;
	u32 damage_x2;
	u32 damage_y1;
	u32 damage_y2;
	u8 lookup_table[4];
	u32 page_offset;
	u32 col_offset;
	u32 prechargep1;
	u32 prechargep2;
	struct pwm_device *pwm;
	struct gpio_desc *reset;
	struct regulator *vbat_reg;
	u32 vcomh;
	u32 width;
	/* Cached address ranges */
	u8 col_start;
	u8 col_end;
	u8 page_start;
	u8 page_end;
};

struct ssd1307fb_array {
	u8	type;
	u8	data[];
};

static const struct fb_fix_screeninfo ssd1307fb_fix = {
	.id		= "Solomon SSD1307",
	.type		= FB_TYPE_PACKED_PIXELS,
	.visual		= FB_VISUAL_MONO10,
	.xpanstep	= 0,
	.ypanstep	= 0,
	.ywrapstep	= 0,
	.accel		= FB_ACCEL_NONE,
};

static const struct fb_var_screeninfo ssd1307fb_var = {
	.bits_per_pixel	= 1,
	.red = { .length = 1 },
	.green = { .length = 1 },
	.blue = { .length = 1 },
};

static struct ssd1307fb_array *ssd1307fb_alloc_array(u32 len, u8 type)
{
	struct ssd1307fb_array *array;

	array = kzalloc(sizeof(struct ssd1307fb_array) + len, GFP_KERNEL);
	if (!array)
		return NULL;

	array->type = type;

	return array;
}

static int ssd1307fb_write_array(struct i2c_client *client,
				 struct ssd1307fb_array *array, u32 len)
{
	int ret;

	len += sizeof(struct ssd1307fb_array);

	ret = i2c_master_send(client, (u8 *)array, len);
	if (ret != len) {
		dev_err(&client->dev, "Couldn't send I2C command.\n");
		return ret;
	}

	return 0;
}

static inline int ssd1307fb_write_cmd(struct i2c_client *client, u8 cmd)
{
	struct ssd1307fb_array *array;
	int ret;

	array = ssd1307fb_alloc_array(1, SSD1307FB_COMMAND);
	if (!array)
		return -ENOMEM;

	array->data[0] = cmd;

	ret = ssd1307fb_write_array(client, array, 1);
	kfree(array);

	return ret;
}

static int ssd1307fb_set_col_range(struct ssd1307fb_par *par, u8 col_start,
				   u8 cols)
{
	u8 col_end = col_start + cols - 1;
	int ret;

	if (col_start == par->col_start && col_end == par->col_end)
		return 0;

	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_COL_RANGE);
	if (ret < 0)
		return ret;

	ret = ssd1307fb_write_cmd(par->client, col_start);
	if (ret < 0)
		return ret;

	ret = ssd1307fb_write_cmd(par->client, col_end);
	if (ret < 0)
		return ret;

	par->col_start = col_start;
	par->col_end =