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git.proxmox.com Git - mirror_ubuntu-eoan-kernel.git/blob - drivers/staging/fbtft/fb_uc1611.c
2 * FB driver for the UltraChip UC1611 LCD controller
4 * The display is 4-bit grayscale (16 shades) 240x160.
6 * Copyright (C) 2015 Henri Chain
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.
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.
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>
28 #define DRVNAME "fb_uc1611"
35 * LCD voltage is a combination of ratio, gain, pot and temp
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
43 /* BR -> actual ratio: 0-3 -> 5, 10, 11, 13 */
44 static unsigned ratio
= 2;
45 module_param(ratio
, uint
, 0);
46 MODULE_PARM_DESC(ratio
, "BR[1:0] Bias voltage ratio: 0-3 (default: 2)");
48 static unsigned gain
= 3;
49 module_param(gain
, uint
, 0);
50 MODULE_PARM_DESC(gain
, "GN[1:0] Bias voltage gain: 0-3 (default: 3)");
52 static unsigned pot
= 16;
53 module_param(pot
, uint
, 0);
54 MODULE_PARM_DESC(pot
, "PM[6:0] Bias voltage pot.: 0-63 (default: 16)");
56 /* TC -> % compensation per deg C: 0-3 -> -.05, -.10, -.015, -.20 */
58 module_param(temp
, uint
, 0);
59 MODULE_PARM_DESC(temp
, "TC[1:0] Temperature compensation: 0-3 (default: 0)");
61 /* PC[1:0] -> LCD capacitance: 0-3 -> <20nF, 20-28 nF, 29-40 nF, 40-56 nF */
62 static unsigned load
= 1;
63 module_param(load
, uint
, 0);
64 MODULE_PARM_DESC(load
, "PC[1:0] Panel Loading: 0-3 (default: 1)");
66 /* PC[3:2] -> V_LCD: 0, 1, 3 -> ext., int. with ratio = 5, int. standard */
67 static unsigned pump
= 3;
68 module_param(pump
, uint
, 0);
69 MODULE_PARM_DESC(pump
, "PC[3:2] Pump control: 0,1,3 (default: 3)");
71 static int init_display(struct fbtft_par
*par
)
75 fbtft_par_dbg(DEBUG_INIT_DISPLAY
, par
, "%s()\n", __func__
);
77 /* Set CS active high */
78 par
->spi
->mode
|= SPI_CS_HIGH
;
79 ret
= par
->spi
->master
->setup(par
->spi
);
81 dev_err(par
->info
->device
, "Could not set SPI_CS_HIGH\n");
85 /* Reset controller */
89 write_reg(par
, 0xE8 | (ratio
& 0x03));
91 /* Set bias gain and potentiometer */
93 write_reg(par
, (gain
& 0x03) << 6 | (pot
& 0x3F));
95 /* Set temperature compensation */
96 write_reg(par
, 0x24 | (temp
& 0x03));
98 /* Set panel loading */
99 write_reg(par
, 0x28 | (load
& 0x03));
101 /* Set pump control */
102 write_reg(par
, 0x2C | (pump
& 0x03));
104 /* Set inverse display */
105 write_reg(par
, 0xA6 | (0x01 & 0x01));
107 /* Set 4-bit grayscale mode */
108 write_reg(par
, 0xD0 | (0x02 & 0x03));
110 /* Set Display enable */
111 write_reg(par
, 0xA8 | 0x07);
116 static void set_addr_win(struct fbtft_par
*par
, int xs
, int ys
, int xe
, int ye
)
118 fbtft_par_dbg(DEBUG_SET_ADDR_WIN
, par
,
119 "%s(xs=%d, ys=%d, xe=%d, ye=%d)\n",
120 __func__
, xs
, ys
, xe
, ye
);
122 switch (par
->info
->var
.rotate
) {
125 /* Set column address */
126 write_reg(par
, ys
& 0x0F);
127 write_reg(par
, 0x10 | (ys
>> 4));
129 /* Set page address (divide xs by 2) (not used by driver) */
130 write_reg(par
, 0x60 | ((xs
>> 1) & 0x0F));
131 write_reg(par
, 0x70 | (xs
>> 5));
134 /* Set column address (not used by driver) */
135 write_reg(par
, xs
& 0x0F);
136 write_reg(par
, 0x10 | (xs
>> 4));
138 /* Set page address (divide ys by 2) */
139 write_reg(par
, 0x60 | ((ys
>> 1) & 0x0F));
140 write_reg(par
, 0x70 | (ys
>> 5));
145 static int blank(struct fbtft_par
*par
, bool on
)
147 fbtft_par_dbg(DEBUG_BLANK
, par
, "%s(blank=%s)\n",
148 __func__
, on
? "true" : "false");
151 write_reg(par
, 0xA8 | 0x00);
153 write_reg(par
, 0xA8 | 0x07);
157 static int set_var(struct fbtft_par
*par
)
159 fbtft_par_dbg(DEBUG_INIT_DISPLAY
, par
, "%s()\n", __func__
);
161 /* par->info->fix.visual = FB_VISUAL_PSEUDOCOLOR; */
162 par
->info
->var
.grayscale
= 1;
163 par
->info
->var
.red
.offset
= 0;
164 par
->info
->var
.red
.length
= 8;
165 par
->info
->var
.green
.offset
= 0;
166 par
->info
->var
.green
.length
= 8;
167 par
->info
->var
.blue
.offset
= 0;
168 par
->info
->var
.blue
.length
= 8;
169 par
->info
->var
.transp
.offset
= 0;
170 par
->info
->var
.transp
.length
= 0;
172 switch (par
->info
->var
.rotate
) {
174 /* Set RAM address control */
176 | (0x0 & 0x1) << 2 /* Increment positively */
177 | (0x1 & 0x1) << 1 /* Increment page first */
178 | (0x1 & 0x1)); /* Wrap around (default) */
180 /* Set LCD mapping */
182 | (0x0 & 0x1) << 2 /* Mirror Y OFF */
183 | (0x0 & 0x1) << 1 /* Mirror X OFF */
184 | (0x0 & 0x1)); /* MS nibble last (default) */
187 /* Set RAM address control */
189 | (0x0 & 0x1) << 2 /* Increment positively */
190 | (0x0 & 0x1) << 1 /* Increment column first */
191 | (0x1 & 0x1)); /* Wrap around (default) */
193 /* Set LCD mapping */
195 | (0x1 & 0x1) << 2 /* Mirror Y ON */
196 | (0x0 & 0x1) << 1 /* Mirror X OFF */
197 | (0x0 & 0x1)); /* MS nibble last (default) */
200 /* Set RAM address control */
202 | (0x0 & 0x1) << 2 /* Increment positively */
203 | (0x1 & 0x1) << 1 /* Increment page first */
204 | (0x1 & 0x1)); /* Wrap around (default) */
206 /* Set LCD mapping */
208 | (0x1 & 0x1) << 2 /* Mirror Y ON */
209 | (0x1 & 0x1) << 1 /* Mirror X ON */
210 | (0x0 & 0x1)); /* MS nibble last (default) */
213 /* Set RAM address control */
215 | (0x0 & 0x1) << 2 /* Increment positively */
216 | (0x0 & 0x1) << 1 /* Increment column first */
217 | (0x1 & 0x1)); /* Wrap around (default) */
219 /* Set LCD mapping */
221 | (0x0 & 0x1) << 2 /* Mirror Y OFF */
222 | (0x1 & 0x1) << 1 /* Mirror X ON */
223 | (0x0 & 0x1)); /* MS nibble last (default) */
230 static int write_vmem(struct fbtft_par
*par
, size_t offset
, size_t len
)
232 u8
*vmem8
= (u8
*)(par
->info
->screen_base
);
233 u8
*buf8
= (u8
*)(par
->txbuf
.buf
);
234 u16
*buf16
= (u16
*)(par
->txbuf
.buf
);
235 int line_length
= par
->info
->fix
.line_length
;
236 int y_start
= (offset
/ line_length
);
237 int y_end
= (offset
+ len
- 1) / line_length
;
241 fbtft_par_dbg(DEBUG_WRITE_VMEM
, par
, "%s()\n", __func__
);
243 switch (par
->pdata
->display
.buswidth
) {
245 switch (par
->info
->var
.rotate
) {
248 i
= y_start
* line_length
;
249 for (y
= y_start
; y
<= y_end
; y
++) {
250 for (x
= 0; x
< line_length
; x
+= 2) {
251 *buf8
= vmem8
[i
] >> 4;
252 *buf8
|= vmem8
[i
+ 1] & 0xF0;
259 /* Must be even because pages are two lines */
261 i
= y_start
* line_length
;
262 for (y
= y_start
; y
<= y_end
; y
+= 2) {
263 for (x
= 0; x
< line_length
; x
++) {
264 *buf8
= vmem8
[i
] >> 4;
265 *buf8
|= vmem8
[i
+ line_length
] & 0xF0;
273 gpio_set_value(par
->gpio
.dc
, 1);
276 ret
= par
->fbtftops
.write(par
, par
->txbuf
.buf
, len
/ 2);
279 switch (par
->info
->var
.rotate
) {
282 i
= y_start
* line_length
;
283 for (y
= y_start
; y
<= y_end
; y
++) {
284 for (x
= 0; x
< line_length
; x
+= 2) {
286 *buf16
|= vmem8
[i
] >> 4;
287 *buf16
|= vmem8
[i
+ 1] & 0xF0;
294 /* Must be even because pages are two lines */
296 i
= y_start
* line_length
;
297 for (y
= y_start
; y
<= y_end
; y
+= 2) {
298 for (x
= 0; x
< line_length
; x
++) {
300 *buf16
|= vmem8
[i
] >> 4;
301 *buf16
|= vmem8
[i
+ line_length
] & 0xF0;
311 ret
= par
->fbtftops
.write(par
, par
->txbuf
.buf
, len
);
314 dev_err(par
->info
->device
, "unsupported buswidth %d\n",
315 par
->pdata
->display
.buswidth
);
319 dev_err(par
->info
->device
, "write failed and returned: %d\n",
325 static struct fbtft_display display
= {
333 .write_vmem
= write_vmem
,
334 .init_display
= init_display
,
335 .set_addr_win
= set_addr_win
,
341 FBTFT_REGISTER_DRIVER(DRVNAME
, "ultrachip,uc1611", &display
);
343 MODULE_ALIAS("spi:" DRVNAME
);
344 MODULE_ALIAS("platform:" DRVNAME
);
345 MODULE_ALIAS("spi:uc1611");
346 MODULE_ALIAS("platform:uc1611");
348 MODULE_DESCRIPTION("FB driver for the UC1611 LCD controller");
349 MODULE_AUTHOR("Henri Chain");
350 MODULE_LICENSE("GPL");