blob: 395cb6a8d8f3a86e3507be05686218ebee6f7d6f [file] [log] [blame]
Maxime Riparda2ed00d2012-12-07 12:30:38 -08001/*
2 * Driver for the Solomon SSD1307 OLED controler
3 *
4 * Copyright 2012 Free Electrons
5 *
6 * Licensed under the GPLv2 or later.
7 */
8
9#include <linux/module.h>
10#include <linux/kernel.h>
11#include <linux/i2c.h>
12#include <linux/fb.h>
13#include <linux/uaccess.h>
14#include <linux/of_device.h>
15#include <linux/of_gpio.h>
16#include <linux/pwm.h>
17#include <linux/delay.h>
18
19#define SSD1307FB_WIDTH 96
20#define SSD1307FB_HEIGHT 16
21
22#define SSD1307FB_DATA 0x40
23#define SSD1307FB_COMMAND 0x80
24
25#define SSD1307FB_CONTRAST 0x81
26#define SSD1307FB_SEG_REMAP_ON 0xa1
27#define SSD1307FB_DISPLAY_OFF 0xae
28#define SSD1307FB_DISPLAY_ON 0xaf
29#define SSD1307FB_START_PAGE_ADDRESS 0xb0
30
31struct ssd1307fb_par {
32 struct i2c_client *client;
33 struct fb_info *info;
34 struct pwm_device *pwm;
35 u32 pwm_period;
36 int reset;
37};
38
Greg Kroah-Hartman48c68c42012-12-21 13:07:39 -080039static struct fb_fix_screeninfo ssd1307fb_fix = {
Maxime Riparda2ed00d2012-12-07 12:30:38 -080040 .id = "Solomon SSD1307",
41 .type = FB_TYPE_PACKED_PIXELS,
42 .visual = FB_VISUAL_MONO10,
43 .xpanstep = 0,
44 .ypanstep = 0,
45 .ywrapstep = 0,
46 .line_length = SSD1307FB_WIDTH / 8,
47 .accel = FB_ACCEL_NONE,
48};
49
Greg Kroah-Hartman48c68c42012-12-21 13:07:39 -080050static struct fb_var_screeninfo ssd1307fb_var = {
Maxime Riparda2ed00d2012-12-07 12:30:38 -080051 .xres = SSD1307FB_WIDTH,
52 .yres = SSD1307FB_HEIGHT,
53 .xres_virtual = SSD1307FB_WIDTH,
54 .yres_virtual = SSD1307FB_HEIGHT,
55 .bits_per_pixel = 1,
56};
57
58static int ssd1307fb_write_array(struct i2c_client *client, u8 type, u8 *cmd, u32 len)
59{
60 u8 *buf;
61 int ret = 0;
62
63 buf = kzalloc(len + 1, GFP_KERNEL);
64 if (!buf) {
65 dev_err(&client->dev, "Couldn't allocate sending buffer.\n");
66 return -ENOMEM;
67 }
68
69 buf[0] = type;
70 memcpy(buf + 1, cmd, len);
71
72 ret = i2c_master_send(client, buf, len + 1);
73 if (ret != len + 1) {
74 dev_err(&client->dev, "Couldn't send I2C command.\n");
75 goto error;
76 }
77
78error:
79 kfree(buf);
80 return ret;
81}
82
83static inline int ssd1307fb_write_cmd_array(struct i2c_client *client, u8 *cmd, u32 len)
84{
85 return ssd1307fb_write_array(client, SSD1307FB_COMMAND, cmd, len);
86}
87
88static inline int ssd1307fb_write_cmd(struct i2c_client *client, u8 cmd)
89{
90 return ssd1307fb_write_cmd_array(client, &cmd, 1);
91}
92
93static inline int ssd1307fb_write_data_array(struct i2c_client *client, u8 *cmd, u32 len)
94{
95 return ssd1307fb_write_array(client, SSD1307FB_DATA, cmd, len);
96}
97
98static inline int ssd1307fb_write_data(struct i2c_client *client, u8 data)
99{
100 return ssd1307fb_write_data_array(client, &data, 1);
101}
102
103static void ssd1307fb_update_display(struct ssd1307fb_par *par)
104{
105 u8 *vmem = par->info->screen_base;
106 int i, j, k;
107
108 /*
109 * The screen is divided in pages, each having a height of 8
110 * pixels, and the width of the screen. When sending a byte of
111 * data to the controller, it gives the 8 bits for the current
112 * column. I.e, the first byte are the 8 bits of the first
113 * column, then the 8 bits for the second column, etc.
114 *
115 *
116 * Representation of the screen, assuming it is 5 bits
117 * wide. Each letter-number combination is a bit that controls
118 * one pixel.
119 *
120 * A0 A1 A2 A3 A4
121 * B0 B1 B2 B3 B4
122 * C0 C1 C2 C3 C4
123 * D0 D1 D2 D3 D4
124 * E0 E1 E2 E3 E4
125 * F0 F1 F2 F3 F4
126 * G0 G1 G2 G3 G4
127 * H0 H1 H2 H3 H4
128 *
129 * If you want to update this screen, you need to send 5 bytes:
130 * (1) A0 B0 C0 D0 E0 F0 G0 H0
131 * (2) A1 B1 C1 D1 E1 F1 G1 H1
132 * (3) A2 B2 C2 D2 E2 F2 G2 H2
133 * (4) A3 B3 C3 D3 E3 F3 G3 H3
134 * (5) A4 B4 C4 D4 E4 F4 G4 H4
135 */
136
137 for (i = 0; i < (SSD1307FB_HEIGHT / 8); i++) {
138 ssd1307fb_write_cmd(par->client, SSD1307FB_START_PAGE_ADDRESS + (i + 1));
139 ssd1307fb_write_cmd(par->client, 0x00);
140 ssd1307fb_write_cmd(par->client, 0x10);
141
142 for (j = 0; j < SSD1307FB_WIDTH; j++) {
143 u8 buf = 0;
144 for (k = 0; k < 8; k++) {
145 u32 page_length = SSD1307FB_WIDTH * i;
146 u32 index = page_length + (SSD1307FB_WIDTH * k + j) / 8;
147 u8 byte = *(vmem + index);
Maxime Ripard552f0cc2013-01-11 14:31:43 -0800148 u8 bit = byte & (1 << (j % 8));
149 bit = bit >> (j % 8);
Maxime Riparda2ed00d2012-12-07 12:30:38 -0800150 buf |= bit << k;
151 }
152 ssd1307fb_write_data(par->client, buf);
153 }
154 }
155}
156
157
158static ssize_t ssd1307fb_write(struct fb_info *info, const char __user *buf,
159 size_t count, loff_t *ppos)
160{
161 struct ssd1307fb_par *par = info->par;
162 unsigned long total_size;
163 unsigned long p = *ppos;
164 u8 __iomem *dst;
165
166 total_size = info->fix.smem_len;
167
168 if (p > total_size)
169 return -EINVAL;
170
171 if (count + p > total_size)
172 count = total_size - p;
173
174 if (!count)
175 return -EINVAL;
176
177 dst = (void __force *) (info->screen_base + p);
178
179 if (copy_from_user(dst, buf, count))
180 return -EFAULT;
181
182 ssd1307fb_update_display(par);
183
184 *ppos += count;
185
186 return count;
187}
188
189static void ssd1307fb_fillrect(struct fb_info *info, const struct fb_fillrect *rect)
190{
191 struct ssd1307fb_par *par = info->par;
192 sys_fillrect(info, rect);
193 ssd1307fb_update_display(par);
194}
195
196static void ssd1307fb_copyarea(struct fb_info *info, const struct fb_copyarea *area)
197{
198 struct ssd1307fb_par *par = info->par;
199 sys_copyarea(info, area);
200 ssd1307fb_update_display(par);
201}
202
203static void ssd1307fb_imageblit(struct fb_info *info, const struct fb_image *image)
204{
205 struct ssd1307fb_par *par = info->par;
206 sys_imageblit(info, image);
207 ssd1307fb_update_display(par);
208}
209
210static struct fb_ops ssd1307fb_ops = {
211 .owner = THIS_MODULE,
212 .fb_read = fb_sys_read,
213 .fb_write = ssd1307fb_write,
214 .fb_fillrect = ssd1307fb_fillrect,
215 .fb_copyarea = ssd1307fb_copyarea,
216 .fb_imageblit = ssd1307fb_imageblit,
217};
218
219static void ssd1307fb_deferred_io(struct fb_info *info,
220 struct list_head *pagelist)
221{
222 ssd1307fb_update_display(info->par);
223}
224
225static struct fb_deferred_io ssd1307fb_defio = {
226 .delay = HZ,
227 .deferred_io = ssd1307fb_deferred_io,
228};
229
Greg Kroah-Hartman48c68c42012-12-21 13:07:39 -0800230static int ssd1307fb_probe(struct i2c_client *client,
231 const struct i2c_device_id *id)
Maxime Riparda2ed00d2012-12-07 12:30:38 -0800232{
233 struct fb_info *info;
234 u32 vmem_size = SSD1307FB_WIDTH * SSD1307FB_HEIGHT / 8;
235 struct ssd1307fb_par *par;
236 u8 *vmem;
237 int ret;
238
239 if (!client->dev.of_node) {
240 dev_err(&client->dev, "No device tree data found!\n");
241 return -EINVAL;
242 }
243
244 info = framebuffer_alloc(sizeof(struct ssd1307fb_par), &client->dev);
245 if (!info) {
246 dev_err(&client->dev, "Couldn't allocate framebuffer.\n");
247 return -ENOMEM;
248 }
249
250 vmem = devm_kzalloc(&client->dev, vmem_size, GFP_KERNEL);
251 if (!vmem) {
252 dev_err(&client->dev, "Couldn't allocate graphical memory.\n");
253 ret = -ENOMEM;
254 goto fb_alloc_error;
255 }
256
257 info->fbops = &ssd1307fb_ops;
258 info->fix = ssd1307fb_fix;
259 info->fbdefio = &ssd1307fb_defio;
260
261 info->var = ssd1307fb_var;
262 info->var.red.length = 1;
263 info->var.red.offset = 0;
264 info->var.green.length = 1;
265 info->var.green.offset = 0;
266 info->var.blue.length = 1;
267 info->var.blue.offset = 0;
268
269 info->screen_base = (u8 __force __iomem *)vmem;
270 info->fix.smem_start = (unsigned long)vmem;
271 info->fix.smem_len = vmem_size;
272
273 fb_deferred_io_init(info);
274
275 par = info->par;
276 par->info = info;
277 par->client = client;
278
279 par->reset = of_get_named_gpio(client->dev.of_node,
280 "reset-gpios", 0);
281 if (!gpio_is_valid(par->reset)) {
282 ret = -EINVAL;
283 goto reset_oled_error;
284 }
285
286 ret = devm_gpio_request_one(&client->dev, par->reset,
287 GPIOF_OUT_INIT_HIGH,
288 "oled-reset");
289 if (ret) {
290 dev_err(&client->dev,
291 "failed to request gpio %d: %d\n",
292 par->reset, ret);
293 goto reset_oled_error;
294 }
295
296 par->pwm = pwm_get(&client->dev, NULL);
297 if (IS_ERR(par->pwm)) {
298 dev_err(&client->dev, "Could not get PWM from device tree!\n");
299 ret = PTR_ERR(par->pwm);
300 goto pwm_error;
301 }
302
303 par->pwm_period = pwm_get_period(par->pwm);
304
305 dev_dbg(&client->dev, "Using PWM%d with a %dns period.\n", par->pwm->pwm, par->pwm_period);
306
307 ret = register_framebuffer(info);
308 if (ret) {
309 dev_err(&client->dev, "Couldn't register the framebuffer\n");
310 goto fbreg_error;
311 }
312
313 i2c_set_clientdata(client, info);
314
315 /* Reset the screen */
316 gpio_set_value(par->reset, 0);
317 udelay(4);
318 gpio_set_value(par->reset, 1);
319 udelay(4);
320
321 /* Enable the PWM */
322 pwm_config(par->pwm, par->pwm_period / 2, par->pwm_period);
323 pwm_enable(par->pwm);
324
325 /* Map column 127 of the OLED to segment 0 */
326 ret = ssd1307fb_write_cmd(client, SSD1307FB_SEG_REMAP_ON);
327 if (ret < 0) {
328 dev_err(&client->dev, "Couldn't remap the screen.\n");
329 goto remap_error;
330 }
331
332 /* Turn on the display */
333 ret = ssd1307fb_write_cmd(client, SSD1307FB_DISPLAY_ON);
334 if (ret < 0) {
335 dev_err(&client->dev, "Couldn't turn the display on.\n");
336 goto remap_error;
337 }
338
339 dev_info(&client->dev, "fb%d: %s framebuffer device registered, using %d bytes of video memory\n", info->node, info->fix.id, vmem_size);
340
341 return 0;
342
343remap_error:
344 unregister_framebuffer(info);
345 pwm_disable(par->pwm);
346fbreg_error:
347 pwm_put(par->pwm);
348pwm_error:
349reset_oled_error:
350 fb_deferred_io_cleanup(info);
351fb_alloc_error:
352 framebuffer_release(info);
353 return ret;
354}
355
Greg Kroah-Hartman48c68c42012-12-21 13:07:39 -0800356static int ssd1307fb_remove(struct i2c_client *client)
Maxime Riparda2ed00d2012-12-07 12:30:38 -0800357{
358 struct fb_info *info = i2c_get_clientdata(client);
359 struct ssd1307fb_par *par = info->par;
360
361 unregister_framebuffer(info);
362 pwm_disable(par->pwm);
363 pwm_put(par->pwm);
364 fb_deferred_io_cleanup(info);
365 framebuffer_release(info);
366
367 return 0;
368}
369
370static const struct i2c_device_id ssd1307fb_i2c_id[] = {
371 { "ssd1307fb", 0 },
372 { }
373};
374MODULE_DEVICE_TABLE(i2c, ssd1307fb_i2c_id);
375
376static const struct of_device_id ssd1307fb_of_match[] = {
377 { .compatible = "solomon,ssd1307fb-i2c" },
378 {},
379};
380MODULE_DEVICE_TABLE(of, ssd1307fb_of_match);
381
382static struct i2c_driver ssd1307fb_driver = {
383 .probe = ssd1307fb_probe,
Greg Kroah-Hartman48c68c42012-12-21 13:07:39 -0800384 .remove = ssd1307fb_remove,
Maxime Riparda2ed00d2012-12-07 12:30:38 -0800385 .id_table = ssd1307fb_i2c_id,
386 .driver = {
387 .name = "ssd1307fb",
388 .of_match_table = of_match_ptr(ssd1307fb_of_match),
389 .owner = THIS_MODULE,
390 },
391};
392
393module_i2c_driver(ssd1307fb_driver);
394
395MODULE_DESCRIPTION("FB driver for the Solomon SSD1307 OLED controler");
396MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
397MODULE_LICENSE("GPL");