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// 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/of_device.h>
#include <linux/of_gpio.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_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_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_par;
struct ssd1307fb_deviceinfo {
u32 default_vcomh;
u32 default_dclk_div;
u32 default_dclk_frq;
int need_pwm;
int need_chargepump;
};
struct ssd1307fb_par {
u32 com_invdir;
u32 com_lrremap;
u32 com_offset;
u32 com_seq;
u32 contrast;
u32 dclk_div;
u32 dclk_frq;
const struct ssd1307fb_deviceinfo *device_info;
struct i2c_client *client;
u32 height;
struct fb_info *info;
u32 page_offset;
u32 prechargep1;
u32 prechargep2;
struct pwm_device *pwm;
u32 pwm_period;
struct gpio_desc *reset;
struct regulator *vbat_reg;
u32 seg_remap;
u32 vcomh;
u32 width;
};
struct ssd1307fb_array {
u8 type;
u8 data[0];
};
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,
};
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_base;
int i, j, k;
array = ssd1307fb_alloc_array(par->width * par->height / 8,
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 < (par->height / 8); i++) {
for (j = 0; j < par->width; j++) {
u32 array_idx = i * par->width + j;
array->data[array_idx] = 0;
for (k = 0; k < 8; k++) {
u32 page_length = par->width * i;
u32 index = page_length + (par->width * k + j) / 8;
u8 byte = *(vmem + index);
u8 bit = byte & (1 << (j % 8));
bit = bit >> (j % 8);
array->data[array_idx] |= bit << k;
}
}
}
ssd1307fb_write_array(par->client, array, par->width * par->height / 8);
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;
u8 __iomem *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 = (void __force *) (info->screen_base + 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 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)
{
int ret;
u32 precharge, dclk, com_invdir, compins;
struct pwm_args pargs;
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);
}
/*
* FIXME: pwm_apply_args() should be removed when switching to
* the atomic PWM API.
*/
pwm_apply_args(par->pwm);
pwm_get_args(par->pwm, &pargs);
par->pwm_period = pargs.period;
/* Enable the PWM */
pwm_config(par->pwm, par->pwm_period / 2, par->pwm_period);
pwm_enable(par->pwm);
dev_dbg(&par->client->dev, "Using PWM%d with a %dns period.\n",
par->pwm->pwm, par->pwm_period);
};
/* 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 & 0x1) << 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 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 & 0x1) << 4
| (par->com_lrremap & 0x1) << 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;
/* 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, 0x0);
if (ret < 0)
return ret;
ret = ssd1307fb_write_cmd(par->client, 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, 0x0);
if (ret < 0)
return ret;
ret = ssd1307fb_write_cmd(par->client,
par->page_offset + (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,
const struct i2c_device_id *id)
{
struct backlight_device *bl;
char bl_name[12];
struct fb_info *info;
struct device_node *node = client->dev.of_node;
struct fb_deferred_io *ssd1307fb_defio;
u32 vmem_size;
struct ssd1307fb_par *par;
u8 *vmem;
int ret;
if (!node) {
dev_err(&client->dev, "No device tree data found!\n");
return -EINVAL;
}
info = framebuffer_alloc(sizeof(struct ssd1307fb_par), &client->dev);
if (!info)
return -ENOMEM;
par = info->par;
par->info = info;
par->client = client;
par->device_info = of_device_get_match_data(&client->dev);
par->reset = devm_gpiod_get_optional(&client->dev, "reset",
GPIOD_OUT_LOW);
if (IS_ERR(par->reset)) {
dev_err(&client->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(&client->dev, "vbat");
if (IS_ERR(par->vbat_reg)) {
ret = PTR_ERR(par->vbat_reg);
if (ret == -ENODEV) {
par->vbat_reg = NULL;
} else {
dev_err(&client->dev, "failed to get VBAT regulator: %d\n",
ret);
goto fb_alloc_error;
}
}
if (of_property_read_u32(node, "solomon,width", &par->width))
par->width = 96;
if (of_property_read_u32(node, "solomon,height", &par->height))
par->height = 16;
if (of_property_read_u32(node, "solomon,page-offset", &par->page_offset))
par->page_offset = 1;
if (of_property_read_u32(node, "solomon,com-offset", &par->com_offset))
par->com_offset = 0;
if (of_property_read_u32(node, "solomon,prechargep1", &par->prechargep1))
par->prechargep1 = 2;
if (of_property_read_u32(node, "solomon,prechargep2", &par->prechargep2))
par->prechargep2 = 2;
par->seg_remap = !of_property_read_bool(node, "solomon,segment-no-remap");
par->com_seq = of_property_read_bool(node, "solomon,com-seq");
par->com_lrremap = of_property_read_bool(node, "solomon,com-lrremap");
par->com_invdir = of_property_read_bool(node, "solomon,com-invdir");
par->contrast = 127;
par->vcomh = par->device_info->default_vcomh;
/* Setup display timing */
par->dclk_div = par->device_info->default_dclk_div;
par->dclk_frq = par->device_info->default_dclk_frq;
vmem_size = par->width * par->height / 8;
vmem = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
get_order(vmem_size));
if (!vmem) {
dev_err(&client->dev, "Couldn't allocate graphical memory.\n");
ret = -ENOMEM;
goto fb_alloc_error;
}
ssd1307fb_defio = devm_kzalloc(&client->dev, sizeof(*ssd1307fb_defio),
GFP_KERNEL);
if (!ssd1307fb_defio) {
dev_err(&client->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 = 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->var.red.length = 1;
info->var.red.offset = 0;
info->var.green.length = 1;
info->var.green.offset = 0;
info->var.blue.length = 1;
info->var.blue.offset = 0;
info->screen_base = (u8 __force __iomem *)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(&client->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(&client->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, &client->dev, par,
&ssd1307fb_bl_ops, NULL);
if (IS_ERR(bl)) {
ret = PTR_ERR(bl);
dev_err(&client->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(&client->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);
};
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 = 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");
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