diff options
Diffstat (limited to 'drivers/video/fbdev/ssd1307fb.c')
| -rw-r--r-- | drivers/video/fbdev/ssd1307fb.c | 581 |
1 files changed, 581 insertions, 0 deletions
diff --git a/drivers/video/fbdev/ssd1307fb.c b/drivers/video/fbdev/ssd1307fb.c new file mode 100644 index 0000000..f4daa59 --- /dev/null +++ b/drivers/video/fbdev/ssd1307fb.c @@ -0,0 +1,581 @@ +/* + * Driver for the Solomon SSD1307 OLED controller + * + * Copyright 2012 Free Electrons + * + * Licensed under the GPLv2 or later. + */ + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/i2c.h> +#include <linux/fb.h> +#include <linux/uaccess.h> +#include <linux/of_device.h> +#include <linux/of_gpio.h> +#include <linux/pwm.h> +#include <linux/delay.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 + +struct ssd1307fb_par; + +struct ssd1307fb_ops { + int (*init)(struct ssd1307fb_par *); + int (*remove)(struct ssd1307fb_par *); +}; + +struct ssd1307fb_par { + struct i2c_client *client; + u32 height; + struct fb_info *info; + struct ssd1307fb_ops *ops; + u32 page_offset; + struct pwm_device *pwm; + u32 pwm_period; + int reset; + u32 width; +}; + +struct ssd1307fb_array { + u8 type; + u8 data[0]; +}; + +static 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 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 inline int ssd1307fb_write_data(struct i2c_client *client, u8 data) +{ + struct ssd1307fb_array *array; + int ret; + + array = ssd1307fb_alloc_array(1, SSD1307FB_DATA); + if (!array) + return -ENOMEM; + + array->data[0] = data; + + 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 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_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 struct fb_deferred_io ssd1307fb_defio = { + .delay = HZ, + .deferred_io = ssd1307fb_deferred_io, +}; + +static int ssd1307fb_ssd1307_init(struct ssd1307fb_par *par) +{ + int ret; + + 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); + } + + par->pwm_period = pwm_get_period(par->pwm); + /* 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); + + /* Map column 127 of the OLED to segment 0 */ + ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SEG_REMAP_ON); + 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_ssd1307_remove(struct ssd1307fb_par *par) +{ + pwm_disable(par->pwm); + pwm_put(par->pwm); + return 0; +} + +static struct ssd1307fb_ops ssd1307fb_ssd1307_ops = { + .init = ssd1307fb_ssd1307_init, + .remove = ssd1307fb_ssd1307_remove, +}; + +static int ssd1307fb_ssd1306_init(struct ssd1307fb_par *par) +{ + int ret; + + /* Set initial contrast */ + ret = ssd1307fb_write_cmd(par->client, SSD1307FB_CONTRAST); + ret = ret & ssd1307fb_write_cmd(par->client, 0x7f); + if (ret < 0) + return ret; + + /* Set COM direction */ + ret = ssd1307fb_write_cmd(par->client, 0xc8); + if (ret < 0) + return ret; + + /* Set segment re-map */ + ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SEG_REMAP_ON); + if (ret < 0) + return ret; + + /* Set multiplex ratio value */ + ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_MULTIPLEX_RATIO); + 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); + ret = ssd1307fb_write_cmd(par->client, 0x20); + if (ret < 0) + return ret; + + /* Set clock frequency */ + ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_CLOCK_FREQ); + ret = ret & ssd1307fb_write_cmd(par->client, 0xf0); + 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); + ret = ret & ssd1307fb_write_cmd(par->client, 0x22); + if (ret < 0) + return ret; + + /* Set COM pins configuration */ + ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_COM_PINS_CONFIG); + ret = ret & ssd1307fb_write_cmd(par->client, 0x22); + if (ret < 0) + return ret; + + /* Set VCOMH */ + ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_VCOMH); + ret = ret & ssd1307fb_write_cmd(par->client, 0x49); + if (ret < 0) + return ret; + + /* Turn on the DC-DC Charge Pump */ + ret = ssd1307fb_write_cmd(par->client, SSD1307FB_CHARGE_PUMP); + ret = ret & ssd1307fb_write_cmd(par->client, 0x14); + if (ret < 0) + return ret; + + /* Switch to horizontal addressing mode */ + ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_ADDRESS_MODE); + ret = ret & ssd1307fb_write_cmd(par->client, + SSD1307FB_SET_ADDRESS_MODE_HORIZONTAL); + if (ret < 0) + return ret; + + ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_COL_RANGE); + ret = ret & ssd1307fb_write_cmd(par->client, 0x0); + ret = ret & ssd1307fb_write_cmd(par->client, par->width - 1); + if (ret < 0) + return ret; + + ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_PAGE_RANGE); + ret = ret & ssd1307fb_write_cmd(par->client, 0x0); + ret = ret & ssd1307fb_write_cmd(par->client, + par->page_offset + (par->height / 8) - 1); + 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 struct ssd1307fb_ops ssd1307fb_ssd1306_ops = { + .init = ssd1307fb_ssd1306_init, +}; + +static const struct of_device_id ssd1307fb_of_match[] = { + { + .compatible = "solomon,ssd1306fb-i2c", + .data = (void *)&ssd1307fb_ssd1306_ops, + }, + { + .compatible = "solomon,ssd1307fb-i2c", + .data = (void *)&ssd1307fb_ssd1307_ops, + }, + {}, +}; +MODULE_DEVICE_TABLE(of, ssd1307fb_of_match); + +static int ssd1307fb_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct fb_info *info; + struct device_node *node = client->dev.of_node; + 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->ops = (struct ssd1307fb_ops *)of_match_device(ssd1307fb_of_match, + &client->dev)->data; + + par->reset = of_get_named_gpio(client->dev.of_node, + "reset-gpios", 0); + if (!gpio_is_valid(par->reset)) { + ret = -EINVAL; + 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->width = 16; + + if (of_property_read_u32(node, "solomon,page-offset", &par->page_offset)) + par->page_offset = 1; + + vmem_size = par->width * par->height / 8; + + vmem = devm_kzalloc(&client->dev, vmem_size, GFP_KERNEL); + if (!vmem) { + dev_err(&client->dev, "Couldn't allocate graphical memory.\n"); + ret = -ENOMEM; + goto fb_alloc_error; + } + + 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 = (unsigned long)vmem; + info->fix.smem_len = vmem_size; + + fb_deferred_io_init(info); + + ret = devm_gpio_request_one(&client->dev, par->reset, + GPIOF_OUT_INIT_HIGH, + "oled-reset"); + if (ret) { + dev_err(&client->dev, + "failed to request gpio %d: %d\n", + par->reset, ret); + goto reset_oled_error; + } + + i2c_set_clientdata(client, info); + + /* Reset the screen */ + gpio_set_value(par->reset, 0); + udelay(4); + gpio_set_value(par->reset, 1); + udelay(4); + + if (par->ops->init) { + ret = par->ops->init(par); + if (ret) + goto reset_oled_error; + } + + ret = register_framebuffer(info); + if (ret) { + dev_err(&client->dev, "Couldn't register the framebuffer\n"); + goto panel_init_error; + } + + 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; + +panel_init_error: + if (par->ops->remove) + par->ops->remove(par); +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; + + unregister_framebuffer(info); + if (par->ops->remove) + par->ops->remove(par); + fb_deferred_io_cleanup(info); + framebuffer_release(info); + + return 0; +} + +static const struct i2c_device_id ssd1307fb_i2c_id[] = { + { "ssd1306fb", 0 }, + { "ssd1307fb", 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, + .owner = THIS_MODULE, + }, +}; + +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"); |