[deliverable/linux.git] / drivers / staging / fbtft / fb_pcd8544.c

/*
 * FB driver for the PCD8544 LCD Controller
 *
 * The display is monochrome and the video memory is RGB565.
 * Any pixel value except 0 turns the pixel on.
 *
 * Copyright (C) 2013 Noralf Tronnes
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/gpio.h>
#include <linux/spi/spi.h>
#include <linux/delay.h>

#include "fbtft.h"

#define DRVNAME	       "fb_pcd8544"
#define WIDTH          84
#define HEIGHT         48
#define TXBUFLEN       (84 * 6)
#define DEFAULT_GAMMA  "40" /* gamma controls the contrast in this driver */

static unsigned int tc;
module_param(tc, uint, 0);
MODULE_PARM_DESC(tc, "TC[1:0] Temperature coefficient: 0-3 (default: 0)");

static unsigned int bs = 4;
module_param(bs, uint, 0);
MODULE_PARM_DESC(bs, "BS[2:0] Bias voltage level: 0-7 (default: 4)");

static int init_display(struct fbtft_par *par)
{
	par->fbtftops.reset(par);

	/* Function set
	 *
	 * 5:1  1
	 * 2:0  PD - Powerdown control: chip is active
	 * 1:0  V  - Entry mode: horizontal addressing
	 * 0:1  H  - Extended instruction set control: extended
	 */
	write_reg(par, 0x21);

	/* H=1 Temperature control
	 *
	 * 2:1  1
	 * 1:x  TC1 - Temperature Coefficient: 0x10
	 * 0:x  TC0
	 */
	write_reg(par, 0x04 | (tc & 0x3));

	/* H=1 Bias system
	 *
	 * 4:1  1
	 * 3:0  0
	 * 2:x  BS2 - Bias System
	 * 1:x  BS1
	 * 0:x  BS0
	 */
	write_reg(par, 0x10 | (bs & 0x7));

	/* Function set
	 *
	 * 5:1  1
	 * 2:0  PD - Powerdown control: chip is active
	 * 1:1  V  - Entry mode: vertical addressing
	 * 0:0  H  - Extended instruction set control: basic
	 */
	write_reg(par, 0x22);

	/* H=0 Display control
	 *
	 * 3:1  1
	 * 2:1  D  - DE: 10=normal mode
	 * 1:0  0
	 * 0:0  E
	 */
	write_reg(par, 0x08 | 4);

	return 0;
}

static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye)
{
	/* H=0 Set X address of RAM
	 *
	 * 7:1  1
	 * 6-0: X[6:0] - 0x00
	 */
	write_reg(par, 0x80);

	/* H=0 Set Y address of RAM
	 *
	 * 7:0  0
	 * 6:1  1
	 * 2-0: Y[2:0] - 0x0
	 */
	write_reg(par, 0x40);
}

static int write_vmem(struct fbtft_par *par, size_t offset, size_t len)
{
	u16 *vmem16 = (u16 *)par->info->screen_buffer;
	u8 *buf = par->txbuf.buf;
	int x, y, i;
	int ret = 0;

	for (x = 0; x < 84; x++) {
		for (y = 0; y < 6; y++) {
			*buf = 0x00;
			for (i = 0; i < 8; i++)
				*buf |= (vmem16[(y * 8 + i) * 84 + x] ?
					 1 : 0) << i;
			buf++;
		}
	}

	/* Write data */
	gpio_set_value(par->gpio.dc, 1);
	ret = par->fbtftops.write(par, par->txbuf.buf, 6 * 84);
	if (ret < 0)
		dev_err(par->info->device, "write failed and returned: %d\n",
			ret);

	return ret;
}

static int set_gamma(struct fbtft_par *par, unsigned long *curves)
{
	/* apply mask */
	curves[0] &= 0x7F;

	write_reg(par, 0x23); /* turn on extended instruction set */
	write_reg(par, 0x80 | curves[0]);
	write_reg(par, 0x22); /* turn off extended instruction set */

	return 0;
}

static struct fbtft_display display = {
	.regwidth = 8,
	.width = WIDTH,
	.height = HEIGHT,
	.txbuflen = TXBUFLEN,
	.gamma_num = 1,
	.gamma_len = 1,
	.gamma = DEFAULT_GAMMA,
	.fbtftops = {
		.init_display = init_display,
		.set_addr_win = set_addr_win,
		.write_vmem = write_vmem,
		.set_gamma = set_gamma,
	},
	.backlight = 1,
};

FBTFT_REGISTER_DRIVER(DRVNAME, "philips,pdc8544", &display);

MODULE_ALIAS("spi:" DRVNAME);
MODULE_ALIAS("spi:pdc8544");

MODULE_DESCRIPTION("FB driver for the PCD8544 LCD Controller");
MODULE_AUTHOR("Noralf Tronnes");
MODULE_LICENSE("GPL");
Commit	Line	Data
39c39072 TP	1	/*
	2	* FB driver for the PCD8544 LCD Controller
	3	*
	4	* The display is monochrome and the video memory is RGB565.
	5	* Any pixel value except 0 turns the pixel on.
	6	*
	7	* Copyright (C) 2013 Noralf Tronnes
	8	*
	9	* This program is free software; you can redistribute it and/or modify
	10	* it under the terms of the GNU General Public License as published by
	11	* the Free Software Foundation; either version 2 of the License, or
	12	* (at your option) any later version.
	13	*
	14	* This program is distributed in the hope that it will be useful,
	15	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	16	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	17	* GNU General Public License for more details.
39c39072 TP	18	*/
	19
	20	#include <linux/module.h>
	21	#include <linux/kernel.h>
	22	#include <linux/init.h>
	23	#include <linux/gpio.h>
	24	#include <linux/spi/spi.h>
	25	#include <linux/delay.h>
	26
	27	#include "fbtft.h"
	28
	29	#define DRVNAME "fb_pcd8544"
	30	#define WIDTH 84
	31	#define HEIGHT 48
94c0a544	32	#define TXBUFLEN (84 * 6)
4178549e	33	#define DEFAULT_GAMMA "40" /* gamma controls the contrast in this driver */
39c39072	34
1c41494a	35	static unsigned int tc;
39c39072 TP	36	module_param(tc, uint, 0);
	37	MODULE_PARM_DESC(tc, "TC[1:0] Temperature coefficient: 0-3 (default: 0)");
	38
1c41494a	39	static unsigned int bs = 4;
39c39072 TP	40	module_param(bs, uint, 0);
	41	MODULE_PARM_DESC(bs, "BS[2:0] Bias voltage level: 0-7 (default: 4)");
	42
39c39072 TP	43	static int init_display(struct fbtft_par *par)
39c39072 TP	44	{
39c39072 TP	45	par->fbtftops.reset(par);
39c39072 TP	46
4178549e CM	47	/* Function set
	48	*
	49	* 5:1 1
	50	* 2:0 PD - Powerdown control: chip is active
	51	* 1:0 V - Entry mode: horizontal addressing
	52	* 0:1 H - Extended instruction set control: extended
	53	*/
	54	write_reg(par, 0x21);
	55
	56	/* H=1 Temperature control
	57	*
	58	* 2:1 1
	59	* 1:x TC1 - Temperature Coefficient: 0x10
	60	* 0:x TC0
	61	*/
	62	write_reg(par, 0x04 \| (tc & 0x3));
	63
	64	/* H=1 Bias system
	65	*
	66	* 4:1 1
	67	* 3:0 0
	68	* 2:x BS2 - Bias System
	69	* 1:x BS1
	70	* 0:x BS0
	71	*/
	72	write_reg(par, 0x10 \| (bs & 0x7));
	73
	74	/* Function set
	75	*
	76	* 5:1 1
	77	* 2:0 PD - Powerdown control: chip is active
	78	* 1:1 V - Entry mode: vertical addressing
	79	* 0:0 H - Extended instruction set control: basic
	80	*/
	81	write_reg(par, 0x22);
	82
	83	/* H=0 Display control
	84	*
	85	* 3:1 1
	86	* 2:1 D - DE: 10=normal mode
	87	* 1:0 0
	88	* 0:0 E
	89	*/
	90	write_reg(par, 0x08 \| 4);
39c39072 TP	91
	92	return 0;
	93	}
	94
	95	static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye)
	96	{
4178549e CM	97	/* H=0 Set X address of RAM
	98	*
	99	* 7:1 1
	100	* 6-0: X[6:0] - 0x00
	101	*/
	102	write_reg(par, 0x80);
	103
	104	/* H=0 Set Y address of RAM
	105	*
	106	* 7:0 0
	107	* 6:1 1
	108	* 2-0: Y[2:0] - 0x0
	109	*/
	110	write_reg(par, 0x40);
39c39072 TP	111	}
	112
	113	static int write_vmem(struct fbtft_par *par, size_t offset, size_t len)
	114	{
4b6dc179	115	u16 vmem16 = (u16 )par->info->screen_buffer;
39c39072 TP	116	u8 *buf = par->txbuf.buf;
	117	int x, y, i;
	118	int ret = 0;
	119
e82fb2b1 HA	120	for (x = 0; x < 84; x++) {
e82fb2b1 HA	121	for (y = 0; y < 6; y++) {
39c39072	122	*buf = 0x00;
9d1d0a38	123	for (i = 0; i < 8; i++)
94c0a544 AB	124	buf \|= (vmem16[(y 8 + i) * 84 + x] ?
94c0a544 AB	125	1 : 0) << i;
39c39072 TP	126	buf++;
	127	}
	128	}
	129
	130	/* Write data */
	131	gpio_set_value(par->gpio.dc, 1);
94c0a544	132	ret = par->fbtftops.write(par, par->txbuf.buf, 6 * 84);
39c39072	133	if (ret < 0)
aed1c72e HM	134	dev_err(par->info->device, "write failed and returned: %d\n",
aed1c72e HM	135	ret);
39c39072 TP	136
	137	return ret;
	138	}
	139
	140	static int set_gamma(struct fbtft_par par, unsigned long curves)
	141	{
39c39072 TP	142	/* apply mask */
	143	curves[0] &= 0x7F;
	144
	145	write_reg(par, 0x23); /* turn on extended instruction set */
	146	write_reg(par, 0x80 \| curves[0]);
	147	write_reg(par, 0x22); /* turn off extended instruction set */
	148
	149	return 0;
	150	}
	151
39c39072 TP	152	static struct fbtft_display display = {
	153	.regwidth = 8,
	154	.width = WIDTH,
	155	.height = HEIGHT,
	156	.txbuflen = TXBUFLEN,
	157	.gamma_num = 1,
	158	.gamma_len = 1,
	159	.gamma = DEFAULT_GAMMA,
	160	.fbtftops = {
	161	.init_display = init_display,
	162	.set_addr_win = set_addr_win,
	163	.write_vmem = write_vmem,
	164	.set_gamma = set_gamma,
	165	},
	166	.backlight = 1,
	167	};
1014c2ce	168
39c39072 TP	169	FBTFT_REGISTER_DRIVER(DRVNAME, "philips,pdc8544", &display);
	170
	171	MODULE_ALIAS("spi:" DRVNAME);
	172	MODULE_ALIAS("spi:pdc8544");
	173
	174	MODULE_DESCRIPTION("FB driver for the PCD8544 LCD Controller");
	175	MODULE_AUTHOR("Noralf Tronnes");
	176	MODULE_LICENSE("GPL");