Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 810 insertions, 0 deletions

diff --git a/drivers/video/fbdev/ssd1307fb.c b/drivers/video/fbdev/ssd1307fb.c
new file mode 100644
index 000000000..eda448b7a
--- /dev/null
+++ b/drivers/video/fbdev/ssd1307fb.c
@@ -0,0 +1,810 @@
+// 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/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;
+	int need_pwm;
+	int 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;
+	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;
+};
+
+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 void ssd1307fb_update_display(struct ssd1307fb_par *par)
+{
+	struct ssd1307fb_array *array;
+	u8 *vmem = par->info->screen_buffer;
+	unsigned int line_length = par->info->fix.line_length;
+	unsigned int pages = DIV_ROUND_UP(par->height, 8);
+	int i, j, k;
+
+	array = ssd1307fb_alloc_array(par->width * pages, SSD1307FB_DATA);
+	if (!array)
+		return;
+
+	/*
+	 * The screen is divided in pages, each having a height of 8
+	 * pixels, and the width of the screen. When sending a byte of
+	 * data to the controller, it gives the 8 bits for the current
+	 * column. I.e, the first byte are the 8 bits of the first
+	 * column, then the 8 bits for the second column, etc.
+	 *
+	 *
+	 * Representation of the screen, assuming it is 5 bits
+	 * wide. Each letter-number combination is a bit that controls
+	 * one pixel.
+	 *
+	 * A0 A1 A2 A3 A4
+	 * B0 B1 B2 B3 B4
+	 * C0 C1 C2 C3 C4
+	 * D0 D1 D2 D3 D4
+	 * E0 E1 E2 E3 E4
+	 * F0 F1 F2 F3 F4
+	 * G0 G1 G2 G3 G4
+	 * H0 H1 H2 H3 H4
+	 *
+	 * If you want to update this screen, you need to send 5 bytes:
+	 *  (1) A0 B0 C0 D0 E0 F0 G0 H0
+	 *  (2) A1 B1 C1 D1 E1 F1 G1 H1
+	 *  (3) A2 B2 C2 D2 E2 F2 G2 H2
+	 *  (4) A3 B3 C3 D3 E3 F3 G3 H3
+	 *  (5) A4 B4 C4 D4 E4 F4 G4 H4
+	 */
+
+	for (i = 0; i < pages; i++) {
+		for (j = 0; j < par->width; j++) {
+			int m = 8;
+			u32 array_idx = i * par->width + j;
+			array->data[array_idx] = 0;
+			/* Last page may be partial */
+			if (i + 1 == pages && par->height % 8)
+				m = par->height % 8;
+			for (k = 0; k < m; k++) {
+				u8 byte = vmem[(8 * i + k) * line_length +
+					       j / 8];
+				u8 bit = (byte >> (j % 8)) & 1;
+				array->data[array_idx] |= bit << k;
+			}
+		}
+	}
+
+	ssd1307fb_write_array(par->client, array, par->width * pages);
+	kfree(array);
+}
+
+
+static ssize_t ssd1307fb_write(struct fb_info *info, const char __user *buf,
+		size_t count, loff_t *ppos)
+{
+	struct ssd1307fb_par *par = info->par;
+	unsigned long total_size;
+	unsigned long p = *ppos;
+	void *dst;
+
+	total_size = info->fix.smem_len;
+
+	if (p > total_size)
+		return -EINVAL;
+
+	if (count + p > total_size)
+		count = total_size - p;
+
+	if (!count)
+		return -EINVAL;
+
+	dst = info->screen_buffer + p;
+
+	if (copy_from_user(dst, buf, count))
+		return -EFAULT;
+
+	ssd1307fb_update_display(par);
+
+	*ppos += count;
+
+	return count;
+}
+
+static int ssd1307fb_blank(int blank_mode, struct fb_info *info)
+{
+	struct ssd1307fb_par *par = info->par;
+
+	if (blank_mode != FB_BLANK_UNBLANK)
+		return ssd1307fb_write_cmd(par->client, SSD1307FB_DISPLAY_OFF);
+	else
+		return ssd1307fb_write_cmd(par->client, SSD1307FB_DISPLAY_ON);
+}
+
+static void ssd1307fb_fillrect(struct fb_info *info, const struct fb_fillrect *rect)
+{
+	struct ssd1307fb_par *par = info->par;
+	sys_fillrect(info, rect);
+	ssd1307fb_update_display(par);
+}
+
+static void ssd1307fb_copyarea(struct fb_info *info, const struct fb_copyarea *area)
+{
+	struct ssd1307fb_par *par = info->par;
+	sys_copyarea(info, area);
+	ssd1307fb_update_display(par);
+}
+
+static void ssd1307fb_imageblit(struct fb_info *info, const struct fb_image *image)
+{
+	struct ssd1307fb_par *par = info->par;
+	sys_imageblit(info, image);
+	ssd1307fb_update_display(par);
+}
+
+static const struct fb_ops ssd1307fb_ops = {
+	.owner		= THIS_MODULE,
+	.fb_read	= fb_sys_read,
+	.fb_write	= ssd1307fb_write,
+	.fb_blank	= ssd1307fb_blank,
+	.fb_fillrect	= ssd1307fb_fillrect,
+	.fb_copyarea	= ssd1307fb_copyarea,
+	.fb_imageblit	= ssd1307fb_imageblit,
+};
+
+static void ssd1307fb_deferred_io(struct fb_info *info,
+				struct list_head *pagelist)
+{
+	ssd1307fb_update_display(info->par);
+}
+
+static int ssd1307fb_init(struct ssd1307fb_par *par)
+{
+	struct pwm_state pwmstate;
+	int ret;
+	u32 precharge, dclk, com_invdir, compins;
+
+	if (par->device_info->need_pwm) {
+		par->pwm = pwm_get(&par->client->dev, NULL);
+		if (IS_ERR(par->pwm)) {
+			dev_err(&par->client->dev, "Could not get PWM from device tree!\n");
+			return PTR_ERR(par->pwm);
+		}
+
+		pwm_init_state(par->pwm, &pwmstate);
+		pwm_set_relative_duty_cycle(&pwmstate, 50, 100);
+		pwm_apply_state(par->pwm, &pwmstate);
+
+		/* Enable the PWM */
+		pwm_enable(par->pwm);
+
+		dev_dbg(&par->client->dev, "Using PWM%d with a %lluns period.\n",
+			par->pwm->pwm, pwm_get_period(par->pwm));
+	}
+
+	/* Set initial contrast */
+	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_CONTRAST);
+	if (ret < 0)
+		return ret;
+
+	ret = ssd1307fb_write_cmd(par->client, par->contrast);
+	if (ret < 0)
+		return ret;
+
+	/* Set segment re-map */
+	if (par->seg_remap) {
+		ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SEG_REMAP_ON);
+		if (ret < 0)
+			return ret;
+	}
+
+	/* Set COM direction */
+	com_invdir = 0xc0 | par->com_invdir << 3;
+	ret = ssd1307fb_write_cmd(par->client,  com_invdir);
+	if (ret < 0)
+		return ret;
+
+	/* Set multiplex ratio value */
+	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_MULTIPLEX_RATIO);
+	if (ret < 0)
+		return ret;
+
+	ret = ssd1307fb_write_cmd(par->client, par->height - 1);
+	if (ret < 0)
+		return ret;
+
+	/* set display offset value */
+	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_DISPLAY_OFFSET);
+	if (ret < 0)
+		return ret;
+
+	ret = ssd1307fb_write_cmd(par->client, par->com_offset);
+	if (ret < 0)
+		return ret;
+
+	/* Set clock frequency */
+	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_CLOCK_FREQ);
+	if (ret < 0)
+		return ret;
+
+	dclk = ((par->dclk_div - 1) & 0xf) | (par->dclk_frq & 0xf) << 4;
+	ret = ssd1307fb_write_cmd(par->client, dclk);
+	if (ret < 0)
+		return ret;
+
+	/* Set Set Area Color Mode ON/OFF & Low Power Display Mode */
+	if (par->area_color_enable || par->low_power) {
+		u32 mode;
+
+		ret = ssd1307fb_write_cmd(par->client,
+					  SSD1307FB_SET_AREA_COLOR_MODE);
+		if (ret < 0)
+			return ret;
+
+		mode = (par->area_color_enable ? 0x30 : 0) |
+			(par->low_power ? 5 : 0);
+		ret = ssd1307fb_write_cmd(par->client, mode);
+		if (ret < 0)
+			return ret;
+	}
+
+	/* Set precharge period in number of ticks from the internal clock */
+	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_PRECHARGE_PERIOD);
+	if (ret < 0)
+		return ret;
+
+	precharge = (par->prechargep1 & 0xf) | (par->prechargep2 & 0xf) << 4;
+	ret = ssd1307fb_write_cmd(par->client, precharge);
+	if (ret < 0)
+		return ret;
+
+	/* Set COM pins configuration */
+	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_COM_PINS_CONFIG);
+	if (ret < 0)
+		return ret;
+
+	compins = 0x02 | !par->com_seq << 4 | par->com_lrremap << 5;
+	ret = ssd1307fb_write_cmd(par->client, compins);
+	if (ret < 0)
+		return ret;
+
+	/* Set VCOMH */
+	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_VCOMH);
+	if (ret < 0)
+		return ret;
+
+	ret = ssd1307fb_write_cmd(par->client, par->vcomh);
+	if (ret < 0)
+		return ret;
+
+	/* Turn on the DC-DC Charge Pump */
+	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_CHARGE_PUMP);
+	if (ret < 0)
+		return ret;
+
+	ret = ssd1307fb_write_cmd(par->client,
+		BIT(4) | (par->device_info->need_chargepump ? BIT(2) : 0));
+	if (ret < 0)
+		return ret;
+
+	/* Set lookup table */
+	if (par->lookup_table_set) {
+		int i;
+
+		ret = ssd1307fb_write_cmd(par->client,
+					  SSD1307FB_SET_LOOKUP_TABLE);
+		if (ret < 0)
+			return ret;
+
+		for (i = 0; i < ARRAY_SIZE(par->lookup_table); ++i) {
+			u8 val = par->lookup_table[i];
+
+			if (val < 31 || val > 63)
+				dev_warn(&par->client->dev,
+					 "lookup table index %d value out of range 31 <= %d <= 63\n",
+					 i, val);
+			ret = ssd1307fb_write_cmd(par->client, val);
+			if (ret < 0)
+				return ret;
+		}
+	}
+
+	/* Switch to horizontal addressing mode */
+	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_ADDRESS_MODE);
+	if (ret < 0)
+		return ret;
+
+	ret = ssd1307fb_write_cmd(par->client,
+				  SSD1307FB_SET_ADDRESS_MODE_HORIZONTAL);
+	if (ret < 0)
+		return ret;
+
+	/* Set column range */
+	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_COL_RANGE);
+	if (ret < 0)
+		return ret;
+
+	ret = ssd1307fb_write_cmd(par->client, par->col_offset);
+	if (ret < 0)
+		return ret;
+
+	ret = ssd1307fb_write_cmd(par->client, par->col_offset + par->width - 1);
+	if (ret < 0)
+		return ret;
+
+	/* Set page range */
+	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_PAGE_RANGE);
+	if (ret < 0)
+		return ret;
+
+	ret = ssd1307fb_write_cmd(par->client, par->page_offset);
+	if (ret < 0)
+		return ret;
+
+	ret = ssd1307fb_write_cmd(par->client,
+				  par->page_offset +
+				  DIV_ROUND_UP(par->height, 8) - 1);
+	if (ret < 0)
+		return ret;
+
+	/* Clear the screen */
+	ssd1307fb_update_display(par);
+
+	/* Turn on the display */
+	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_DISPLAY_ON);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static int ssd1307fb_update_bl(struct backlight_device *bdev)
+{
+	struct ssd1307fb_par *par = bl_get_data(bdev);
+	int ret;
+	int brightness = bdev->props.brightness;
+
+	par->contrast = brightness;
+
+	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_CONTRAST);
+	if (ret < 0)
+		return ret;
+	ret = ssd1307fb_write_cmd(par->client, par->contrast);
+	if (ret < 0)
+		return ret;
+	return 0;
+}
+
+static int ssd1307fb_get_brightness(struct backlight_device *bdev)
+{
+	struct ssd1307fb_par *par = bl_get_data(bdev);
+
+	return par->contrast;
+}
+
+static int ssd1307fb_check_fb(struct backlight_device *bdev,
+				   struct fb_info *info)
+{
+	return (info->bl_dev == bdev);
+}
+
+static const struct backlight_ops ssd1307fb_bl_ops = {
+	.options	= BL_CORE_SUSPENDRESUME,
+	.update_status	= ssd1307fb_update_bl,
+	.get_brightness	= ssd1307fb_get_brightness,
+	.check_fb	= ssd1307fb_check_fb,
+};
+
+static struct ssd1307fb_deviceinfo ssd1307fb_ssd1305_deviceinfo = {
+	.default_vcomh = 0x34,
+	.default_dclk_div = 1,
+	.default_dclk_frq = 7,
+};
+
+static struct ssd1307fb_deviceinfo ssd1307fb_ssd1306_deviceinfo = {
+	.default_vcomh = 0x20,
+	.default_dclk_div = 1,
+	.default_dclk_frq = 8,
+	.need_chargepump = 1,
+};
+
+static struct ssd1307fb_deviceinfo ssd1307fb_ssd1307_deviceinfo = {
+	.default_vcomh = 0x20,
+	.default_dclk_div = 2,
+	.default_dclk_frq = 12,
+	.need_pwm = 1,
+};
+
+static struct ssd1307fb_deviceinfo ssd1307fb_ssd1309_deviceinfo = {
+	.default_vcomh = 0x34,
+	.default_dclk_div = 1,
+	.default_dclk_frq = 10,
+};
+
+static const struct of_device_id ssd1307fb_of_match[] = {
+	{
+		.compatible = "solomon,ssd1305fb-i2c",
+		.data = (void *)&ssd1307fb_ssd1305_deviceinfo,
+	},
+	{
+		.compatible = "solomon,ssd1306fb-i2c",
+		.data = (void *)&ssd1307fb_ssd1306_deviceinfo,
+	},
+	{
+		.compatible = "solomon,ssd1307fb-i2c",
+		.data = (void *)&ssd1307fb_ssd1307_deviceinfo,
+	},
+	{
+		.compatible = "solomon,ssd1309fb-i2c",
+		.data = (void *)&ssd1307fb_ssd1309_deviceinfo,
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, ssd1307fb_of_match);
+
+static int ssd1307fb_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct backlight_device *bl;
+	char bl_name[12];
+	struct fb_info *info;
+	struct fb_deferred_io *ssd1307fb_defio;
+	u32 vmem_size;
+	struct ssd1307fb_par *par;
+	void *vmem;
+	int ret;
+
+	info = framebuffer_alloc(sizeof(struct ssd1307fb_par), dev);
+	if (!info)
+		return -ENOMEM;
+
+	par = info->par;
+	par->info = info;
+	par->client = client;
+
+	par->device_info = device_get_match_data(dev);
+
+	par->reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(par->reset)) {
+		dev_err(dev, "failed to get reset gpio: %ld\n",
+			PTR_ERR(par->reset));
+		ret = PTR_ERR(par->reset);
+		goto fb_alloc_error;
+	}
+
+	par->vbat_reg = devm_regulator_get_optional(dev, "vbat");
+	if (IS_ERR(par->vbat_reg)) {
+		ret = PTR_ERR(par->vbat_reg);
+		if (ret == -ENODEV) {
+			par->vbat_reg = NULL;
+		} else {
+			dev_err(dev, "failed to get VBAT regulator: %d\n", ret);
+			goto fb_alloc_error;
+		}
+	}
+
+	if (device_property_read_u32(dev, "solomon,width", &par->width))
+		par->width = 96;
+
+	if (device_property_read_u32(dev, "solomon,height", &par->height))
+		par->height = 16;
+
+	if (device_property_read_u32(dev, "solomon,page-offset", &par->page_offset))
+		par->page_offset = 1;
+
+	if (device_property_read_u32(dev, "solomon,col-offset", &par->col_offset))
+		par->col_offset = 0;
+
+	if (device_property_read_u32(dev, "solomon,com-offset", &par->com_offset))
+		par->com_offset = 0;
+
+	if (device_property_read_u32(dev, "solomon,prechargep1", &par->prechargep1))
+		par->prechargep1 = 2;
+
+	if (device_property_read_u32(dev, "solomon,prechargep2", &par->prechargep2))
+		par->prechargep2 = 2;
+
+	if (!device_property_read_u8_array(dev, "solomon,lookup-table",
+					   par->lookup_table,
+					   ARRAY_SIZE(par->lookup_table)))
+		par->lookup_table_set = 1;
+
+	par->seg_remap = !device_property_read_bool(dev, "solomon,segment-no-remap");
+	par->com_seq = device_property_read_bool(dev, "solomon,com-seq");
+	par->com_lrremap = device_property_read_bool(dev, "solomon,com-lrremap");
+	par->com_invdir = device_property_read_bool(dev, "solomon,com-invdir");
+	par->area_color_enable =
+		device_property_read_bool(dev, "solomon,area-color-enable");
+	par->low_power = device_property_read_bool(dev, "solomon,low-power");
+
+	par->contrast = 127;
+	par->vcomh = par->device_info->default_vcomh;
+
+	/* Setup display timing */
+	if (device_property_read_u32(dev, "solomon,dclk-div", &par->dclk_div))
+		par->dclk_div = par->device_info->default_dclk_div;
+	if (device_property_read_u32(dev, "solomon,dclk-frq", &par->dclk_frq))
+		par->dclk_frq = par->device_info->default_dclk_frq;
+
+	vmem_size = DIV_ROUND_UP(par->width, 8) * par->height;
+
+	vmem = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
+					get_order(vmem_size));
+	if (!vmem) {
+		dev_err(dev, "Couldn't allocate graphical memory.\n");
+		ret = -ENOMEM;
+		goto fb_alloc_error;
+	}
+
+	ssd1307fb_defio = devm_kzalloc(dev, sizeof(*ssd1307fb_defio),
+				       GFP_KERNEL);
+	if (!ssd1307fb_defio) {
+		dev_err(dev, "Couldn't allocate deferred io.\n");
+		ret = -ENOMEM;
+		goto fb_alloc_error;
+	}
+
+	ssd1307fb_defio->delay = HZ / refreshrate;
+	ssd1307fb_defio->deferred_io = ssd1307fb_deferred_io;
+
+	info->fbops = &ssd1307fb_ops;
+	info->fix = ssd1307fb_fix;
+	info->fix.line_length = DIV_ROUND_UP(par->width, 8);
+	info->fbdefio = ssd1307fb_defio;
+
+	info->var = ssd1307fb_var;
+	info->var.xres = par->width;
+	info->var.xres_virtual = par->width;
+	info->var.yres = par->height;
+	info->var.yres_virtual = par->height;
+
+	info->screen_buffer = vmem;
+	info->fix.smem_start = __pa(vmem);
+	info->fix.smem_len = vmem_size;
+
+	fb_deferred_io_init(info);
+
+	i2c_set_clientdata(client, info);
+
+	if (par->reset) {
+		/* Reset the screen */
+		gpiod_set_value_cansleep(par->reset, 1);
+		udelay(4);
+		gpiod_set_value_cansleep(par->reset, 0);
+		udelay(4);
+	}
+
+	if (par->vbat_reg) {
+		ret = regulator_enable(par->vbat_reg);
+		if (ret) {
+			dev_err(dev, "failed to enable VBAT: %d\n", ret);
+			goto reset_oled_error;
+		}
+	}
+
+	ret = ssd1307fb_init(par);
+	if (ret)
+		goto regulator_enable_error;
+
+	ret = register_framebuffer(info);
+	if (ret) {
+		dev_err(dev, "Couldn't register the framebuffer\n");
+		goto panel_init_error;
+	}
+
+	snprintf(bl_name, sizeof(bl_name), "ssd1307fb%d", info->node);
+	bl = backlight_device_register(bl_name, dev, par, &ssd1307fb_bl_ops,
+				       NULL);
+	if (IS_ERR(bl)) {
+		ret = PTR_ERR(bl);
+		dev_err(dev, "unable to register backlight device: %d\n", ret);
+		goto bl_init_error;
+	}
+
+	bl->props.brightness = par->contrast;
+	bl->props.max_brightness = MAX_CONTRAST;
+	info->bl_dev = bl;
+
+	dev_info(dev, "fb%d: %s framebuffer device registered, using %d bytes of video memory\n", info->node, info->fix.id, vmem_size);
+
+	return 0;
+
+bl_init_error:
+	unregister_framebuffer(info);
+panel_init_error:
+	if (par->device_info->need_pwm) {
+		pwm_disable(par->pwm);
+		pwm_put(par->pwm);
+	}
+regulator_enable_error:
+	if (par->vbat_reg)
+		regulator_disable(par->vbat_reg);
+reset_oled_error:
+	fb_deferred_io_cleanup(info);
+fb_alloc_error:
+	framebuffer_release(info);
+	return ret;
+}
+
+static int ssd1307fb_remove(struct i2c_client *client)
+{
+	struct fb_info *info = i2c_get_clientdata(client);
+	struct ssd1307fb_par *par = info->par;
+
+	ssd1307fb_write_cmd(par->client, SSD1307FB_DISPLAY_OFF);
+
+	backlight_device_unregister(info->bl_dev);
+
+	unregister_framebuffer(info);
+	if (par->device_info->need_pwm) {
+		pwm_disable(par->pwm);
+		pwm_put(par->pwm);
+	}
+	if (par->vbat_reg)
+		regulator_disable(par->vbat_reg);
+	fb_deferred_io_cleanup(info);
+	__free_pages(__va(info->fix.smem_start), get_order(info->fix.smem_len));
+	framebuffer_release(info);
+
+	return 0;
+}
+
+static const struct i2c_device_id ssd1307fb_i2c_id[] = {
+	{ "ssd1305fb", 0 },
+	{ "ssd1306fb", 0 },
+	{ "ssd1307fb", 0 },
+	{ "ssd1309fb", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, ssd1307fb_i2c_id);
+
+static struct i2c_driver ssd1307fb_driver = {
+	.probe_new = ssd1307fb_probe,
+	.remove = ssd1307fb_remove,
+	.id_table = ssd1307fb_i2c_id,
+	.driver = {
+		.name = "ssd1307fb",
+		.of_match_table = ssd1307fb_of_match,
+	},
+};
+
+module_i2c_driver(ssd1307fb_driver);
+
+MODULE_DESCRIPTION("FB driver for the Solomon SSD1307 OLED controller");
+MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
+MODULE_LICENSE("GPL");