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Commit | Line | Data |
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a2ed00da | 1 | /* |
a895d57d | 2 | * Driver for the Solomon SSD1307 OLED controller |
a2ed00da MR |
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 | ||
31 | struct 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 | ||
48c68c4f | 39 | static struct fb_fix_screeninfo ssd1307fb_fix = { |
a2ed00da MR |
40 | .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 | ||
48c68c4f | 50 | static struct fb_var_screeninfo ssd1307fb_var = { |
a2ed00da MR |
51 | .xres = SSD1307FB_WIDTH, |
52 | .yres = SSD1307FB_HEIGHT, | |
53 | .xres_virtual = SSD1307FB_WIDTH, | |
54 | .yres_virtual = SSD1307FB_HEIGHT, | |
55 | .bits_per_pixel = 1, | |
56 | }; | |
57 | ||
58 | static 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 | ||
78 | error: | |
79 | kfree(buf); | |
80 | return ret; | |
81 | } | |
82 | ||
83 | static 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 | ||
88 | static inline int ssd1307fb_write_cmd(struct i2c_client *client, u8 cmd) | |
89 | { | |
90 | return ssd1307fb_write_cmd_array(client, &cmd, 1); | |
91 | } | |
92 | ||
93 | static 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 | ||
98 | static inline int ssd1307fb_write_data(struct i2c_client *client, u8 data) | |
99 | { | |
100 | return ssd1307fb_write_data_array(client, &data, 1); | |
101 | } | |
102 | ||
103 | static 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); | |
552f0cc7 MR |
148 | u8 bit = byte & (1 << (j % 8)); |
149 | bit = bit >> (j % 8); | |
a2ed00da MR |
150 | buf |= bit << k; |
151 | } | |
152 | ssd1307fb_write_data(par->client, buf); | |
153 | } | |
154 | } | |
155 | } | |
156 | ||
157 | ||
158 | static 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 | ||
189 | static 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 | ||
196 | static 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 | ||
203 | static 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 | ||
210 | static 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 | ||
219 | static void ssd1307fb_deferred_io(struct fb_info *info, | |
220 | struct list_head *pagelist) | |
221 | { | |
222 | ssd1307fb_update_display(info->par); | |
223 | } | |
224 | ||
225 | static struct fb_deferred_io ssd1307fb_defio = { | |
226 | .delay = HZ, | |
227 | .deferred_io = ssd1307fb_deferred_io, | |
228 | }; | |
229 | ||
48c68c4f GKH |
230 | static int ssd1307fb_probe(struct i2c_client *client, |
231 | const struct i2c_device_id *id) | |
a2ed00da MR |
232 | { |
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 | ||
343 | remap_error: | |
344 | unregister_framebuffer(info); | |
345 | pwm_disable(par->pwm); | |
346 | fbreg_error: | |
347 | pwm_put(par->pwm); | |
348 | pwm_error: | |
349 | reset_oled_error: | |
350 | fb_deferred_io_cleanup(info); | |
351 | fb_alloc_error: | |
352 | framebuffer_release(info); | |
353 | return ret; | |
354 | } | |
355 | ||
48c68c4f | 356 | static int ssd1307fb_remove(struct i2c_client *client) |
a2ed00da MR |
357 | { |
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 | ||
370 | static const struct i2c_device_id ssd1307fb_i2c_id[] = { | |
371 | { "ssd1307fb", 0 }, | |
372 | { } | |
373 | }; | |
374 | MODULE_DEVICE_TABLE(i2c, ssd1307fb_i2c_id); | |
375 | ||
376 | static const struct of_device_id ssd1307fb_of_match[] = { | |
377 | { .compatible = "solomon,ssd1307fb-i2c" }, | |
378 | {}, | |
379 | }; | |
380 | MODULE_DEVICE_TABLE(of, ssd1307fb_of_match); | |
381 | ||
382 | static struct i2c_driver ssd1307fb_driver = { | |
383 | .probe = ssd1307fb_probe, | |
48c68c4f | 384 | .remove = ssd1307fb_remove, |
a2ed00da MR |
385 | .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 | ||
393 | module_i2c_driver(ssd1307fb_driver); | |
394 | ||
a895d57d | 395 | MODULE_DESCRIPTION("FB driver for the Solomon SSD1307 OLED controller"); |
a2ed00da MR |
396 | MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>"); |
397 | MODULE_LICENSE("GPL"); |