// 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;
        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;
        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 = col_end;
        return 0;
}

static int ssd1307fb_set_page_range(struct ssd1307fb_par *par, u8 page_start,
                                    u8 pages)
{
        u8 page_end = page_start + pages - 1;
        int ret;

        if (page_start == par->page_start && page_end == par->page_end)
                return 0;

        ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_PAGE_RANGE);
        if (ret < 0)
                return ret;

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

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

        par->page_start = page_start;
        par->page_end = page_end;
        return 0;
}

static int ssd1307fb_update_rect(struct ssd1307fb_par *par, unsigned int x,
                                 unsigned int y, unsigned int width,
                                 unsigned int height)
{
        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(y % 8 + height, 8);
        u32 array_idx = 0;
        int ret, i, j, k;

        array = ssd1307fb_alloc_array(width * pages, SSD1307FB_DATA);
        if (!array)
                return -ENOMEM;

        /*
         * 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
         */

        ret = ssd1307fb_set_col_range(par, par->col_offset + x, width);
        if (ret < 0)
                goto out_free;

        ret = ssd1307fb_set_page_range(par, par->page_offset + y / 8, pages);
        if (ret < 0)
                goto out_free;

        for (i = y / 8; i < y / 8 + pages; i++) {
                int m = 8;

                /* Last page may be partial */
                if (8 * (i + 1) > par->height)
                        m = par->height % 8;
                for (j = x; j < x + width; j++) {
                        u8 data = 0;

                        for (k = 0; k < m; k++) {
                                u8 byte = vmem[(8 * i + k) * line_length +
                                               j / 8];
                                u8 bit = (byte >> (j % 8)) & 1;
                                data |= bit << k;
                        }
                        array->data[array_idx++] = data;
                }
        }

        ret = ssd1307fb_write_array(par->client, array, width * pages);

out_free:
        kfree(array);
        return ret;
}

static int ssd1307fb_update_display(struct ssd1307fb_par *par)
{
        return ssd1307fb_update_rect(par, 0, 0, par->width, par->height);
}

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_defio_damage_range(struct fb_info *info, off_t off, size_t len)
{
        struct ssd1307fb_par *par = info->par;

        ssd1307fb_update_display(par);
}

static void ssd1307fb_defio_damage_area(struct fb_info *info, u32 x, u32 y,
                                        u32 width, u32 height)
{
        struct ssd1307fb_par *par = info->par;

        ssd1307fb_update_rect(par, x, y, width, height);
}

FB_GEN_DEFAULT_DEFERRED_SYSMEM_OPS(ssd1307fb,
                                   ssd1307fb_defio_damage_range,
                                   ssd1307fb_defio_damage_area)

static const struct fb_ops ssd1307fb_ops = {
        .owner          = THIS_MODULE,
        FB_DEFAULT_DEFERRED_OPS(ssd1307fb),
        .fb_blank       = ssd1307fb_blank,
};

static void ssd1307fb_deferred_io(struct fb_info *info, struct list_head *pagereflist)
{
        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_might_sleep(par->pwm, &pwmstate);

                /* Enable the PWM */
                pwm_enable(par->pwm);

                dev_dbg(&par->client->dev, "Using PWM %s with a %lluns period.\n",
                        par->pwm->label, 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 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;

        /* Clear the screen */
        ret = ssd1307fb_update_display(par);
        if (ret < 0)
                return ret;

        /* 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 const struct backlight_ops ssd1307fb_bl_ops = {
        .options        = BL_CORE_SUSPENDRESUME,
        .update_status  = ssd1307fb_update_bl,
        .get_brightness = ssd1307fb_get_brightness,
};

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;
        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)) {
                ret = dev_err_probe(dev, PTR_ERR(par->reset),
                                    "failed to get reset gpio\n");
                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_probe(dev, ret, "failed to get VBAT regulator\n");
                        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_defio_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;

        bl = backlight_device_register("ssd1307fb-bl", 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 panel_init_error;
        }
        info->bl_dev = bl;

        ret = register_framebuffer(info);
        if (ret) {
                dev_err(dev, "Couldn't register the framebuffer\n");
                goto fb_init_error;
        }

        bl->props.brightness = par->contrast;
        bl->props.max_brightness = MAX_CONTRAST;

        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;

fb_init_error:
        backlight_device_unregister(bl);
panel_init_error:
        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_defio_error:
        __free_pages(vmem, get_order(vmem_size));
fb_alloc_error:
        framebuffer_release(info);
        return ret;
}

static void 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);
        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);
}

static const struct i2c_device_id ssd1307fb_i2c_id[] = {
        { "ssd1305fb" },
        { "ssd1306fb" },
        { "ssd1307fb" },
        { "ssd1309fb" },
        { }
};
MODULE_DEVICE_TABLE(i2c, ssd1307fb_i2c_id);

static struct i2c_driver ssd1307fb_driver = {
        .probe = 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");