drivers/staging/fbtft/fb_ssd1351.c - arm/linux - Git at Google

 #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_ssd1351"
 #define WIDTH		128
 #define HEIGHT		128
 #define GAMMA_NUM	1
 #define GAMMA_LEN	63
 #define DEFAULT_GAMMA	"0 2 2 2 2 2 2 2 " \
 			"2 2 2 2 2 2 2 2 " \
 			"2 2 2 2 2 2 2 2 " \
 			"2 2 2 2 2 2 2 2 " \
 			"2 2 2 2 2 2 2 2 " \
 			"2 2 2 2 2 2 2 2 " \
 			"2 2 2 2 2 2 2 2 " \
 			"2 2 2 2 2 2 2" \

 static void register_onboard_backlight(struct fbtft_par *par);

 static int init_display(struct fbtft_par *par)
 {
 	if (par->pdata &&
 	    par->pdata->display.backlight == FBTFT_ONBOARD_BACKLIGHT) {
 		/* module uses onboard GPIO for panel power */
 		par->fbtftops.register_backlight = register_onboard_backlight;
 	}

 	par->fbtftops.reset(par);

 	write_reg(par, 0xfd, 0x12); /* Command Lock */
 	write_reg(par, 0xfd, 0xb1); /* Command Lock */
 	write_reg(par, 0xae); /* Display Off */
 	write_reg(par, 0xb3, 0xf1); /* Front Clock Div */
 	write_reg(par, 0xca, 0x7f); /* Set Mux Ratio */
 	write_reg(par, 0x15, 0x00, 0x7f); /* Set Column Address */
 	write_reg(par, 0x75, 0x00, 0x7f); /* Set Row Address */
 	write_reg(par, 0xa1, 0x00); /* Set Display Start Line */
 	write_reg(par, 0xa2, 0x00); /* Set Display Offset */
 	write_reg(par, 0xb5, 0x00); /* Set GPIO */
 	write_reg(par, 0xab, 0x01); /* Set Function Selection */
 	write_reg(par, 0xb1, 0x32); /* Set Phase Length */
 	write_reg(par, 0xb4, 0xa0, 0xb5, 0x55); /* Set Segment Low Voltage */
 	write_reg(par, 0xbb, 0x17); /* Set Precharge Voltage */
 	write_reg(par, 0xbe, 0x05); /* Set VComH Voltage */
 	write_reg(par, 0xc1, 0xc8, 0x80, 0xc8); /* Set Contrast */
 	write_reg(par, 0xc7, 0x0f); /* Set Master Contrast */
 	write_reg(par, 0xb6, 0x01); /* Set Second Precharge Period */
 	write_reg(par, 0xa6); /* Set Display Mode Reset */
 	write_reg(par, 0xaf); /* Set Sleep Mode Display On */

 	return 0;
 }

 static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye)
 {
 	write_reg(par, 0x15, xs, xe);
 	write_reg(par, 0x75, ys, ye);
 	write_reg(par, 0x5c);
 }

 static int set_var(struct fbtft_par *par)
 {
 	unsigned int remap;

 	if (par->fbtftops.init_display != init_display) {
 		/* don't risk messing up register A0h */
 		fbtft_par_dbg(DEBUG_INIT_DISPLAY, par,
 			      "%s: skipping since custom init_display() is used\n",
 			       __func__);
 		return 0;
 	}

 	remap = 0x60 | (par->bgr << 2); /* Set Colour Depth */

 	switch (par->info->var.rotate) {
 	case 0:
 		write_reg(par, 0xA0, remap | 0x00 | 1 << 4);
 		break;
 	case 270:
 		write_reg(par, 0xA0, remap | 0x03 | 1 << 4);
 		break;
 	case 180:
 		write_reg(par, 0xA0, remap | 0x02);
 		break;
 	case 90:
 		write_reg(par, 0xA0, remap | 0x01);
 		break;
 	}

 	return 0;
 }

 /*
  * Grayscale Lookup Table
  * GS1 - GS63
  * The driver Gamma curve contains the relative values between the entries
  * in the Lookup table.
  *
  * From datasheet:
  * 8.8 Gray Scale Decoder
  *
  *	there are total 180 Gamma Settings (Setting 0 to Setting 180)
  *	available for the Gray Scale table.
  *
  *	The gray scale is defined in incremental way, with reference
  *	to the length of previous table entry:
  *		Setting of GS1 has to be >= 0
  *		Setting of GS2 has to be > Setting of GS1 +1
  *		Setting of GS3 has to be > Setting of GS2 +1
  *		:
  *		Setting of GS63 has to be > Setting of GS62 +1
  *
  */
 static int set_gamma(struct fbtft_par *par, u32 *curves)
 {
 	unsigned long tmp[GAMMA_NUM * GAMMA_LEN];
 	int i, acc = 0;

 	for (i = 0; i < 63; i++) {
 		if (i > 0 && curves[i] < 2) {
 			dev_err(par->info->device,
 				"Illegal value in Grayscale Lookup Table at index %d. " \
 				"Must be greater than 1\n", i);
 			return -EINVAL;
 		}
 		acc += curves[i];
 		tmp[i] = acc;
 		if (acc > 180) {
 			dev_err(par->info->device,
 				"Illegal value(s) in Grayscale Lookup Table. " \
 				"At index=%d, the accumulated value has exceeded 180\n", i);
 			return -EINVAL;
 		}
 	}

 	write_reg(par, 0xB8,
 	tmp[0], tmp[1], tmp[2], tmp[3], tmp[4], tmp[5], tmp[6], tmp[7],
 	tmp[8], tmp[9], tmp[10], tmp[11], tmp[12], tmp[13], tmp[14], tmp[15],
 	tmp[16], tmp[17], tmp[18], tmp[19], tmp[20], tmp[21], tmp[22], tmp[23],
 	tmp[24], tmp[25], tmp[26], tmp[27], tmp[28], tmp[29], tmp[30], tmp[31],
 	tmp[32], tmp[33], tmp[34], tmp[35], tmp[36], tmp[37], tmp[38], tmp[39],
 	tmp[40], tmp[41], tmp[42], tmp[43], tmp[44], tmp[45], tmp[46], tmp[47],
 	tmp[48], tmp[49], tmp[50], tmp[51], tmp[52], tmp[53], tmp[54], tmp[55],
 	tmp[56], tmp[57], tmp[58], tmp[59], tmp[60], tmp[61], tmp[62]);

 	return 0;
 }

 static int blank(struct fbtft_par *par, bool on)
 {
 	fbtft_par_dbg(DEBUG_BLANK, par, "%s(blank=%s)\n",
 		__func__, on ? "true" : "false");
 	if (on)
 		write_reg(par, 0xAE);
 	else
 		write_reg(par, 0xAF);
 	return 0;
 }

 static struct fbtft_display display = {
 	.regwidth = 8,
 	.width = WIDTH,
 	.height = HEIGHT,
 	.gamma_num = GAMMA_NUM,
 	.gamma_len = GAMMA_LEN,
 	.gamma = DEFAULT_GAMMA,
 	.fbtftops = {
 		.init_display = init_display,
 		.set_addr_win = set_addr_win,
 		.set_var = set_var,
 		.set_gamma = set_gamma,
 		.blank = blank,
 	},
 };

 #ifdef CONFIG_FB_BACKLIGHT
 static int update_onboard_backlight(struct backlight_device *bd)
 {
 	struct fbtft_par *par = bl_get_data(bd);
 	bool on;

 	fbtft_par_dbg(DEBUG_BACKLIGHT, par,
 		"%s: power=%d, fb_blank=%d\n",
 		__func__, bd->props.power, bd->props.fb_blank);

 	on = (bd->props.power == FB_BLANK_UNBLANK) &&
 	     (bd->props.fb_blank == FB_BLANK_UNBLANK);
 	/* Onboard backlight connected to GPIO0 on SSD1351, GPIO1 unused */
 	write_reg(par, 0xB5, on ? 0x03 : 0x02);

 	return 0;
 }

 static const struct backlight_ops bl_ops = {
 	.update_status = update_onboard_backlight,
 };

 static void register_onboard_backlight(struct fbtft_par *par)
 {
 	struct backlight_device *bd;
 	struct backlight_properties bl_props = { 0, };

 	bl_props.type = BACKLIGHT_RAW;
 	bl_props.power = FB_BLANK_POWERDOWN;

 	bd = backlight_device_register(dev_driver_string(par->info->device),
 				par->info->device, par, &bl_ops, &bl_props);
 	if (IS_ERR(bd)) {
 		dev_err(par->info->device,
 			"cannot register backlight device (%ld)\n",
 			PTR_ERR(bd));
 		return;
 	}
 	par->info->bl_dev = bd;

 	if (!par->fbtftops.unregister_backlight)
 		par->fbtftops.unregister_backlight = fbtft_unregister_backlight;
 }
 #else
 static void register_onboard_backlight(struct fbtft_par *par) { };
 #endif

 FBTFT_REGISTER_DRIVER(DRVNAME, "solomon,ssd1351", &display);

 MODULE_ALIAS("spi:" DRVNAME);
 MODULE_ALIAS("platform:" DRVNAME);
 MODULE_ALIAS("spi:ssd1351");
 MODULE_ALIAS("platform:ssd1351");

 MODULE_DESCRIPTION("SSD1351 OLED Driver");
 MODULE_AUTHOR("James Davies");
 MODULE_LICENSE("GPL");
	#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_ssd1351"
	#define WIDTH 128
	#define HEIGHT 128
	#define GAMMA_NUM 1
	#define GAMMA_LEN 63
	#define DEFAULT_GAMMA "0 2 2 2 2 2 2 2 " \
	"2 2 2 2 2 2 2 2 " \
	"2 2 2 2 2 2 2 2 " \
	"2 2 2 2 2 2 2 2 " \
	"2 2 2 2 2 2 2 2 " \
	"2 2 2 2 2 2 2 2 " \
	"2 2 2 2 2 2 2 2 " \
	"2 2 2 2 2 2 2" \

	static void register_onboard_backlight(struct fbtft_par *par);

	static int init_display(struct fbtft_par *par)
	{
	if (par->pdata &&
	par->pdata->display.backlight == FBTFT_ONBOARD_BACKLIGHT) {
	/* module uses onboard GPIO for panel power */
	par->fbtftops.register_backlight = register_onboard_backlight;
	}

	par->fbtftops.reset(par);

	write_reg(par, 0xfd, 0x12); /* Command Lock */
	write_reg(par, 0xfd, 0xb1); /* Command Lock */
	write_reg(par, 0xae); /* Display Off */
	write_reg(par, 0xb3, 0xf1); /* Front Clock Div */
	write_reg(par, 0xca, 0x7f); /* Set Mux Ratio */
	write_reg(par, 0x15, 0x00, 0x7f); /* Set Column Address */
	write_reg(par, 0x75, 0x00, 0x7f); /* Set Row Address */
	write_reg(par, 0xa1, 0x00); /* Set Display Start Line */
	write_reg(par, 0xa2, 0x00); /* Set Display Offset */
	write_reg(par, 0xb5, 0x00); /* Set GPIO */
	write_reg(par, 0xab, 0x01); /* Set Function Selection */
	write_reg(par, 0xb1, 0x32); /* Set Phase Length */
	write_reg(par, 0xb4, 0xa0, 0xb5, 0x55); /* Set Segment Low Voltage */
	write_reg(par, 0xbb, 0x17); /* Set Precharge Voltage */
	write_reg(par, 0xbe, 0x05); /* Set VComH Voltage */
	write_reg(par, 0xc1, 0xc8, 0x80, 0xc8); /* Set Contrast */
	write_reg(par, 0xc7, 0x0f); /* Set Master Contrast */
	write_reg(par, 0xb6, 0x01); /* Set Second Precharge Period */
	write_reg(par, 0xa6); /* Set Display Mode Reset */
	write_reg(par, 0xaf); /* Set Sleep Mode Display On */

	return 0;
	}

	static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye)
	{
	write_reg(par, 0x15, xs, xe);
	write_reg(par, 0x75, ys, ye);
	write_reg(par, 0x5c);
	}

	static int set_var(struct fbtft_par *par)
	{
	unsigned int remap;

	if (par->fbtftops.init_display != init_display) {
	/* don't risk messing up register A0h */
	fbtft_par_dbg(DEBUG_INIT_DISPLAY, par,
	"%s: skipping since custom init_display() is used\n",
	__func__);
	return 0;
	}

	remap = 0x60 \| (par->bgr << 2); /* Set Colour Depth */

	switch (par->info->var.rotate) {
	case 0:
	write_reg(par, 0xA0, remap \| 0x00 \| 1 << 4);
	break;
	case 270:
	write_reg(par, 0xA0, remap \| 0x03 \| 1 << 4);
	break;
	case 180:
	write_reg(par, 0xA0, remap \| 0x02);
	break;
	case 90:
	write_reg(par, 0xA0, remap \| 0x01);
	break;
	}

	return 0;
	}

	/*
	* Grayscale Lookup Table
	* GS1 - GS63
	* The driver Gamma curve contains the relative values between the entries
	* in the Lookup table.
	*
	* From datasheet:
	* 8.8 Gray Scale Decoder
	*
	* there are total 180 Gamma Settings (Setting 0 to Setting 180)
	* available for the Gray Scale table.
	*
	* The gray scale is defined in incremental way, with reference
	* to the length of previous table entry:
	* Setting of GS1 has to be >= 0
	* Setting of GS2 has to be > Setting of GS1 +1
	* Setting of GS3 has to be > Setting of GS2 +1
	* :
	* Setting of GS63 has to be > Setting of GS62 +1
	*
	*/
	static int set_gamma(struct fbtft_par par, u32 curves)
	{
	unsigned long tmp[GAMMA_NUM * GAMMA_LEN];
	int i, acc = 0;

	for (i = 0; i < 63; i++) {
	if (i > 0 && curves[i] < 2) {
	dev_err(par->info->device,
	"Illegal value in Grayscale Lookup Table at index %d. " \
	"Must be greater than 1\n", i);
	return -EINVAL;
	}
	acc += curves[i];
	tmp[i] = acc;
	if (acc > 180) {
	dev_err(par->info->device,
	"Illegal value(s) in Grayscale Lookup Table. " \
	"At index=%d, the accumulated value has exceeded 180\n", i);
	return -EINVAL;
	}
	}

	write_reg(par, 0xB8,
	tmp[0], tmp[1], tmp[2], tmp[3], tmp[4], tmp[5], tmp[6], tmp[7],
	tmp[8], tmp[9], tmp[10], tmp[11], tmp[12], tmp[13], tmp[14], tmp[15],
	tmp[16], tmp[17], tmp[18], tmp[19], tmp[20], tmp[21], tmp[22], tmp[23],
	tmp[24], tmp[25], tmp[26], tmp[27], tmp[28], tmp[29], tmp[30], tmp[31],
	tmp[32], tmp[33], tmp[34], tmp[35], tmp[36], tmp[37], tmp[38], tmp[39],
	tmp[40], tmp[41], tmp[42], tmp[43], tmp[44], tmp[45], tmp[46], tmp[47],
	tmp[48], tmp[49], tmp[50], tmp[51], tmp[52], tmp[53], tmp[54], tmp[55],
	tmp[56], tmp[57], tmp[58], tmp[59], tmp[60], tmp[61], tmp[62]);

	return 0;
	}

	static int blank(struct fbtft_par *par, bool on)
	{
	fbtft_par_dbg(DEBUG_BLANK, par, "%s(blank=%s)\n",
	__func__, on ? "true" : "false");
	if (on)
	write_reg(par, 0xAE);
	else
	write_reg(par, 0xAF);
	return 0;
	}

	static struct fbtft_display display = {
	.regwidth = 8,
	.width = WIDTH,
	.height = HEIGHT,
	.gamma_num = GAMMA_NUM,
	.gamma_len = GAMMA_LEN,
	.gamma = DEFAULT_GAMMA,
	.fbtftops = {
	.init_display = init_display,
	.set_addr_win = set_addr_win,
	.set_var = set_var,
	.set_gamma = set_gamma,
	.blank = blank,
	},
	};

	#ifdef CONFIG_FB_BACKLIGHT
	static int update_onboard_backlight(struct backlight_device *bd)
	{
	struct fbtft_par *par = bl_get_data(bd);
	bool on;

	fbtft_par_dbg(DEBUG_BACKLIGHT, par,
	"%s: power=%d, fb_blank=%d\n",
	__func__, bd->props.power, bd->props.fb_blank);

	on = (bd->props.power == FB_BLANK_UNBLANK) &&
	(bd->props.fb_blank == FB_BLANK_UNBLANK);
	/* Onboard backlight connected to GPIO0 on SSD1351, GPIO1 unused */
	write_reg(par, 0xB5, on ? 0x03 : 0x02);

	return 0;
	}

	static const struct backlight_ops bl_ops = {
	.update_status = update_onboard_backlight,
	};

	static void register_onboard_backlight(struct fbtft_par *par)
	{
	struct backlight_device *bd;
	struct backlight_properties bl_props = { 0, };

	bl_props.type = BACKLIGHT_RAW;
	bl_props.power = FB_BLANK_POWERDOWN;

	bd = backlight_device_register(dev_driver_string(par->info->device),
	par->info->device, par, &bl_ops, &bl_props);
	if (IS_ERR(bd)) {
	dev_err(par->info->device,
	"cannot register backlight device (%ld)\n",
	PTR_ERR(bd));
	return;
	}
	par->info->bl_dev = bd;

	if (!par->fbtftops.unregister_backlight)
	par->fbtftops.unregister_backlight = fbtft_unregister_backlight;
	}
	#else
	static void register_onboard_backlight(struct fbtft_par *par) { };
	#endif

	FBTFT_REGISTER_DRIVER(DRVNAME, "solomon,ssd1351", &display);

	MODULE_ALIAS("spi:" DRVNAME);
	MODULE_ALIAS("platform:" DRVNAME);
	MODULE_ALIAS("spi:ssd1351");
	MODULE_ALIAS("platform:ssd1351");

	MODULE_DESCRIPTION("SSD1351 OLED Driver");
	MODULE_AUTHOR("James Davies");
	MODULE_LICENSE("GPL");