/* * Driver for the Solomon SSD1307 OLED controller * * Copyright 2012 Free Electrons * * Licensed under the GPLv2 or later. */ #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) { dev_err(&client->dev, "Couldn't allocate framebuffer.\n"); 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(par->reset, 0); udelay(4); gpiod_set_value(par->reset, 1); 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");