Merge remote-tracking branch 'staging/staging-next'
[deliverable/linux.git] / drivers / staging / fbtft / fb_uc1611.c
CommitLineData
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1/*
2 * FB driver for the UltraChip UC1611 LCD controller
3 *
4 * The display is 4-bit grayscale (16 shades) 240x160.
5 *
6 * Copyright (C) 2015 Henri Chain
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 */
18
19#include <linux/module.h>
20#include <linux/kernel.h>
21#include <linux/init.h>
22#include <linux/gpio.h>
23#include <linux/spi/spi.h>
24#include <linux/delay.h>
25
26#include "fbtft.h"
27
28#define DRVNAME "fb_uc1611"
29#define WIDTH 240
30#define HEIGHT 160
31#define BPP 8
32#define FPS 40
33
34/*
35 * LCD voltage is a combination of ratio, gain, pot and temp
36 *
37 * V_LCD = V_BIAS * ratio
38 * V_LCD = (C_V0 + C_PM × pot) * (1 + (T - 25) * temp)
39 * C_V0 and C_PM depend on ratio and gain
40 * T is ambient temperature
41 */
42
43/* BR -> actual ratio: 0-3 -> 5, 10, 11, 13 */
1c41494a 44static unsigned int ratio = 2;
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45module_param(ratio, uint, 0);
46MODULE_PARM_DESC(ratio, "BR[1:0] Bias voltage ratio: 0-3 (default: 2)");
47
1c41494a 48static unsigned int gain = 3;
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49module_param(gain, uint, 0);
50MODULE_PARM_DESC(gain, "GN[1:0] Bias voltage gain: 0-3 (default: 3)");
51
1c41494a 52static unsigned int pot = 16;
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53module_param(pot, uint, 0);
54MODULE_PARM_DESC(pot, "PM[6:0] Bias voltage pot.: 0-63 (default: 16)");
55
56/* TC -> % compensation per deg C: 0-3 -> -.05, -.10, -.015, -.20 */
1c41494a 57static unsigned int temp;
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58module_param(temp, uint, 0);
59MODULE_PARM_DESC(temp, "TC[1:0] Temperature compensation: 0-3 (default: 0)");
60
61/* PC[1:0] -> LCD capacitance: 0-3 -> <20nF, 20-28 nF, 29-40 nF, 40-56 nF */
1c41494a 62static unsigned int load = 1;
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63module_param(load, uint, 0);
64MODULE_PARM_DESC(load, "PC[1:0] Panel Loading: 0-3 (default: 1)");
65
66/* PC[3:2] -> V_LCD: 0, 1, 3 -> ext., int. with ratio = 5, int. standard */
1c41494a 67static unsigned int pump = 3;
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68module_param(pump, uint, 0);
69MODULE_PARM_DESC(pump, "PC[3:2] Pump control: 0,1,3 (default: 3)");
70
71static int init_display(struct fbtft_par *par)
72{
73 int ret;
74
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75 /* Set CS active high */
76 par->spi->mode |= SPI_CS_HIGH;
dd3afa57 77 ret = spi_setup(par->spi);
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78 if (ret) {
79 dev_err(par->info->device, "Could not set SPI_CS_HIGH\n");
80 return ret;
81 }
82
83 /* Reset controller */
84 write_reg(par, 0xE2);
85
86 /* Set bias ratio */
87 write_reg(par, 0xE8 | (ratio & 0x03));
88
89 /* Set bias gain and potentiometer */
90 write_reg(par, 0x81);
91 write_reg(par, (gain & 0x03) << 6 | (pot & 0x3F));
92
93 /* Set temperature compensation */
94 write_reg(par, 0x24 | (temp & 0x03));
95
96 /* Set panel loading */
97 write_reg(par, 0x28 | (load & 0x03));
98
99 /* Set pump control */
100 write_reg(par, 0x2C | (pump & 0x03));
101
102 /* Set inverse display */
103 write_reg(par, 0xA6 | (0x01 & 0x01));
104
105 /* Set 4-bit grayscale mode */
106 write_reg(par, 0xD0 | (0x02 & 0x03));
107
108 /* Set Display enable */
109 write_reg(par, 0xA8 | 0x07);
110
111 return 0;
112}
113
114static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye)
115{
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116 switch (par->info->var.rotate) {
117 case 90:
118 case 270:
119 /* Set column address */
120 write_reg(par, ys & 0x0F);
121 write_reg(par, 0x10 | (ys >> 4));
122
123 /* Set page address (divide xs by 2) (not used by driver) */
124 write_reg(par, 0x60 | ((xs >> 1) & 0x0F));
125 write_reg(par, 0x70 | (xs >> 5));
126 break;
127 default:
128 /* Set column address (not used by driver) */
129 write_reg(par, xs & 0x0F);
130 write_reg(par, 0x10 | (xs >> 4));
131
132 /* Set page address (divide ys by 2) */
133 write_reg(par, 0x60 | ((ys >> 1) & 0x0F));
134 write_reg(par, 0x70 | (ys >> 5));
135 break;
136 }
137}
138
139static int blank(struct fbtft_par *par, bool on)
140{
141 fbtft_par_dbg(DEBUG_BLANK, par, "%s(blank=%s)\n",
142 __func__, on ? "true" : "false");
143
144 if (on)
145 write_reg(par, 0xA8 | 0x00);
146 else
147 write_reg(par, 0xA8 | 0x07);
148 return 0;
149}
150
151static int set_var(struct fbtft_par *par)
152{
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153 /* par->info->fix.visual = FB_VISUAL_PSEUDOCOLOR; */
154 par->info->var.grayscale = 1;
155 par->info->var.red.offset = 0;
156 par->info->var.red.length = 8;
157 par->info->var.green.offset = 0;
158 par->info->var.green.length = 8;
159 par->info->var.blue.offset = 0;
160 par->info->var.blue.length = 8;
161 par->info->var.transp.offset = 0;
162 par->info->var.transp.length = 0;
163
164 switch (par->info->var.rotate) {
165 case 90:
166 /* Set RAM address control */
167 write_reg(par, 0x88
168 | (0x0 & 0x1) << 2 /* Increment positively */
169 | (0x1 & 0x1) << 1 /* Increment page first */
170 | (0x1 & 0x1)); /* Wrap around (default) */
171
172 /* Set LCD mapping */
173 write_reg(par, 0xC0
174 | (0x0 & 0x1) << 2 /* Mirror Y OFF */
175 | (0x0 & 0x1) << 1 /* Mirror X OFF */
176 | (0x0 & 0x1)); /* MS nibble last (default) */
177 break;
178 case 180:
179 /* Set RAM address control */
180 write_reg(par, 0x88
181 | (0x0 & 0x1) << 2 /* Increment positively */
182 | (0x0 & 0x1) << 1 /* Increment column first */
183 | (0x1 & 0x1)); /* Wrap around (default) */
184
185 /* Set LCD mapping */
186 write_reg(par, 0xC0
187 | (0x1 & 0x1) << 2 /* Mirror Y ON */
188 | (0x0 & 0x1) << 1 /* Mirror X OFF */
189 | (0x0 & 0x1)); /* MS nibble last (default) */
190 break;
191 case 270:
192 /* Set RAM address control */
193 write_reg(par, 0x88
194 | (0x0 & 0x1) << 2 /* Increment positively */
195 | (0x1 & 0x1) << 1 /* Increment page first */
196 | (0x1 & 0x1)); /* Wrap around (default) */
197
198 /* Set LCD mapping */
199 write_reg(par, 0xC0
200 | (0x1 & 0x1) << 2 /* Mirror Y ON */
201 | (0x1 & 0x1) << 1 /* Mirror X ON */
202 | (0x0 & 0x1)); /* MS nibble last (default) */
203 break;
204 default:
205 /* Set RAM address control */
206 write_reg(par, 0x88
207 | (0x0 & 0x1) << 2 /* Increment positively */
208 | (0x0 & 0x1) << 1 /* Increment column first */
209 | (0x1 & 0x1)); /* Wrap around (default) */
210
211 /* Set LCD mapping */
212 write_reg(par, 0xC0
213 | (0x0 & 0x1) << 2 /* Mirror Y OFF */
214 | (0x1 & 0x1) << 1 /* Mirror X ON */
215 | (0x0 & 0x1)); /* MS nibble last (default) */
216 break;
217 }
218
219 return 0;
220}
221
222static int write_vmem(struct fbtft_par *par, size_t offset, size_t len)
223{
4b6dc179 224 u8 *vmem8 = (u8 *)(par->info->screen_buffer);
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225 u8 *buf8 = par->txbuf.buf;
226 u16 *buf16 = par->txbuf.buf;
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227 int line_length = par->info->fix.line_length;
228 int y_start = (offset / line_length);
229 int y_end = (offset + len - 1) / line_length;
230 int x, y, i;
231 int ret = 0;
232
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233 switch (par->pdata->display.buswidth) {
234 case 8:
235 switch (par->info->var.rotate) {
236 case 90:
237 case 270:
238 i = y_start * line_length;
239 for (y = y_start; y <= y_end; y++) {
240 for (x = 0; x < line_length; x += 2) {
241 *buf8 = vmem8[i] >> 4;
242 *buf8 |= vmem8[i + 1] & 0xF0;
243 buf8++;
244 i += 2;
245 }
246 }
247 break;
248 default:
249 /* Must be even because pages are two lines */
250 y_start &= 0xFE;
251 i = y_start * line_length;
252 for (y = y_start; y <= y_end; y += 2) {
253 for (x = 0; x < line_length; x++) {
254 *buf8 = vmem8[i] >> 4;
255 *buf8 |= vmem8[i + line_length] & 0xF0;
256 buf8++;
257 i++;
258 }
259 i += line_length;
260 }
261 break;
262 }
263 gpio_set_value(par->gpio.dc, 1);
264
265 /* Write data */
266 ret = par->fbtftops.write(par, par->txbuf.buf, len / 2);
267 break;
268 case 9:
269 switch (par->info->var.rotate) {
270 case 90:
271 case 270:
272 i = y_start * line_length;
273 for (y = y_start; y <= y_end; y++) {
274 for (x = 0; x < line_length; x += 2) {
275 *buf16 = 0x100;
276 *buf16 |= vmem8[i] >> 4;
277 *buf16 |= vmem8[i + 1] & 0xF0;
278 buf16++;
279 i += 2;
280 }
281 }
282 break;
283 default:
284 /* Must be even because pages are two lines */
285 y_start &= 0xFE;
286 i = y_start * line_length;
287 for (y = y_start; y <= y_end; y += 2) {
288 for (x = 0; x < line_length; x++) {
289 *buf16 = 0x100;
290 *buf16 |= vmem8[i] >> 4;
291 *buf16 |= vmem8[i + line_length] & 0xF0;
292 buf16++;
293 i++;
294 }
295 i += line_length;
296 }
297 break;
298 }
299
300 /* Write data */
301 ret = par->fbtftops.write(par, par->txbuf.buf, len);
302 break;
303 default:
304 dev_err(par->info->device, "unsupported buswidth %d\n",
305 par->pdata->display.buswidth);
306 }
307
308 if (ret < 0)
309 dev_err(par->info->device, "write failed and returned: %d\n",
310 ret);
311
312 return ret;
313}
314
315static struct fbtft_display display = {
316 .txbuflen = -1,
317 .regwidth = 8,
318 .width = WIDTH,
319 .height = HEIGHT,
320 .bpp = BPP,
321 .fps = FPS,
322 .fbtftops = {
323 .write_vmem = write_vmem,
324 .init_display = init_display,
325 .set_addr_win = set_addr_win,
326 .set_var = set_var,
327 .blank = blank,
328 },
329};
330
331FBTFT_REGISTER_DRIVER(DRVNAME, "ultrachip,uc1611", &display);
332
333MODULE_ALIAS("spi:" DRVNAME);
334MODULE_ALIAS("platform:" DRVNAME);
335MODULE_ALIAS("spi:uc1611");
336MODULE_ALIAS("platform:uc1611");
337
338MODULE_DESCRIPTION("FB driver for the UC1611 LCD controller");
339MODULE_AUTHOR("Henri Chain");
340MODULE_LICENSE("GPL");
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