staging: fbtft: add fb_hx8340bn driver

This commit adds the fb_hx8340bn driver from the fbtft project at
https://github.com/notro/fbtft.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Noralf Tronnes <notro@tronnes.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/fbtft/Kconfig

@@ -19,3 +19,9 @@ config FB_TFT_BD663474
 	depends on FB_TFT
 	help
 	  Generic Framebuffer support for BD663474
+
+config FB_TFT_HX8340BN
+	tristate "FB driver for the HX8340BN LCD Controller"
+	depends on FB_TFT
+	help
+	  Generic Framebuffer support for HX8340BN

drivers/staging/fbtft/Makefile

@@ -5,3 +5,4 @@ fbtft-y                          += fbtft-core.o fbtft-sysfs.o fbtft-bus.o fbtft
 # drivers
 obj-$(CONFIG_FB_TFT_AGM1264K_FL) += fb_agm1264k-fl.o
 obj-$(CONFIG_FB_TFT_BD663474)    += fb_bd663474.o
+obj-$(CONFIG_FB_TFT_HX8340BN)    += fb_hx8340bn.o

drivers/staging/fbtft/fb_hx8340bn.c

+/*
+ * FB driver for the HX8340BN LCD Controller
+ *
+ * This display uses 9-bit SPI: Data/Command bit + 8 data bits
+ * For platforms that doesn't support 9-bit, the driver is capable
+ * of emulating this using 8-bit transfer.
+ * This is done by transfering eight 9-bit words in 9 bytes.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/vmalloc.h>
+#include <linux/spi/spi.h>
+#include <linux/delay.h>
+
+#include "fbtft.h"
+
+#define DRVNAME		"fb_hx8340bn"
+#define WIDTH		176
+#define HEIGHT		220
+#define TXBUFLEN	(4 * PAGE_SIZE)
+#define DEFAULT_GAMMA	"1 3 0E 5 0 2 09 0 6 1 7 1 0 2 2\n" \
+			"3 3 17 8 4 7 05 7 6 0 3 1 6 0 0 "
+
+
+static bool emulate;
+module_param(emulate, bool, 0);
+MODULE_PARM_DESC(emulate, "Force emulation in 9-bit mode");
+
+
+static int init_display(struct fbtft_par *par)
+{
+	fbtft_par_dbg(DEBUG_INIT_DISPLAY, par, "%s()\n", __func__);
+
+	par->fbtftops.reset(par);
+
+	/* BTL221722-276L startup sequence, from datasheet */
+
+	/* SETEXTCOM: Set extended command set (C1h)
+	   This command is used to set extended command set access enable.
+	   Enable: After command (C1h), must write: ffh,83h,40h */
+	write_reg(par, 0xC1, 0xFF, 0x83, 0x40);
+
+	/* Sleep out
+	   This command turns off sleep mode.
+	   In this mode the DC/DC converter is enabled, Internal oscillator
+	   is started, and panel scanning is started. */
+	write_reg(par, 0x11);
+	mdelay(150);
+
+	/* Undoc'd register? */
+	write_reg(par, 0xCA, 0x70, 0x00, 0xD9);
+
+	/* SETOSC: Set Internal Oscillator (B0h)
+	   This command is used to set internal oscillator related settings */
+	/*	OSC_EN: Enable internal oscillator */
+	/*	Internal oscillator frequency: 125% x 2.52MHz */
+	write_reg(par, 0xB0, 0x01, 0x11);
+
+	/* Drive ability setting */
+	write_reg(par, 0xC9, 0x90, 0x49, 0x10, 0x28, 0x28, 0x10, 0x00, 0x06);
+	mdelay(20);
+
+	/* SETPWCTR5: Set Power Control 5(B5h)
+	   This command is used to set VCOM Low and VCOM High Voltage */
+	/* VCOMH 0110101 :  3.925 */
+	/* VCOML 0100000 : -1.700 */
+	/* 45h=69  VCOMH: "VMH" + 5d   VCOML: "VMH" + 5d */
+	write_reg(par, 0xB5, 0x35, 0x20, 0x45);
+
+	/* SETPWCTR4: Set Power Control 4(B4h)
+		VRH[4:0]:	Specify the VREG1 voltage adjusting.
+				VREG1 voltage is for gamma voltage setting.
+		BT[2:0]:	Switch the output factor of step-up circuit 2
+				for VGH and VGL voltage generation. */
+	write_reg(par, 0xB4, 0x33, 0x25, 0x4C);
+	mdelay(10);
+
+	/* Interface Pixel Format (3Ah)
+	   This command is used to define the format of RGB picture data,
+	   which is to be transfer via the system and RGB interface. */
+	/* RGB interface: 16 Bit/Pixel	*/
+	write_reg(par, 0x3A, 0x05);
+
+	/* Display on (29h)
+	   This command is used to recover from DISPLAY OFF mode.
+	   Output from the Frame Memory is enabled. */
+	write_reg(par, 0x29);
+	mdelay(10);
+
+	return 0;
+}
+
+void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye)
+{
+	fbtft_par_dbg(DEBUG_SET_ADDR_WIN, par,
+		"%s(xs=%d, ys=%d, xe=%d, ye=%d)\n", __func__, xs, ys, xe, ye);
+
+	write_reg(par, FBTFT_CASET, 0x00, xs, 0x00, xe);
+	write_reg(par, FBTFT_RASET, 0x00, ys, 0x00, ye);
+	write_reg(par, FBTFT_RAMWR);
+}
+
+static int set_var(struct fbtft_par *par)
+{
+	fbtft_par_dbg(DEBUG_INIT_DISPLAY, par, "%s()\n", __func__);
+
+	/* MADCTL - Memory data access control */
+	/* RGB/BGR can be set with H/W pin SRGB and MADCTL BGR bit */
+#define MY (1 << 7)
+#define MX (1 << 6)
+#define MV (1 << 5)
+	switch (par->info->var.rotate) {
+	case 0:
+		write_reg(par, 0x36, (par->bgr << 3));
+		break;
+	case 270:
+		write_reg(par, 0x36, MX | MV | (par->bgr << 3));
+		break;
+	case 180:
+		write_reg(par, 0x36, MX | MY | (par->bgr << 3));
+		break;
+	case 90:
+		write_reg(par, 0x36, MY | MV | (par->bgr << 3));
+		break;
+	}
+
+	return 0;
+}
+
+/*
+  Gamma Curve selection, GC (only GC0 can be customized):
+    0 = 2.2, 1 = 1.8, 2 = 2.5, 3 = 1.0
+  Gamma string format:
+    OP0 OP1 CP0 CP1 CP2 CP3 CP4 MP0 MP1 MP2 MP3 MP4 MP5 CGM0 CGM1
+    ON0 ON1 CN0 CN1 CN2 CN3 CN4 MN0 MN1 MN2 MN3 MN4 MN5 XXXX  GC
+*/
+#define CURVE(num, idx)  curves[num*par->gamma.num_values + idx]
+static int set_gamma(struct fbtft_par *par, unsigned long *curves)
+{
+	unsigned long mask[] = {
+		0b1111, 0b1111, 0b11111, 0b1111, 0b1111, 0b1111, 0b11111,
+		0b111, 0b111, 0b111, 0b111, 0b111, 0b111, 0b11, 0b11,
+		0b1111, 0b1111, 0b11111, 0b1111, 0b1111, 0b1111, 0b11111,
+		0b111, 0b111, 0b111, 0b111, 0b111, 0b111, 0b0, 0b0 };
+	int i, j;
+
+	fbtft_par_dbg(DEBUG_INIT_DISPLAY, par, "%s()\n", __func__);
+
+	/* apply mask */
+	for (i = 0; i < par->gamma.num_curves; i++)
+		for (j = 0; j < par->gamma.num_values; j++)
+			CURVE(i, j) &= mask[i * par->gamma.num_values + j];
+
+	write_reg(par, 0x26, 1 << CURVE(1, 14)); /* Gamma Set (26h) */
+
+	if (CURVE(1, 14))
+		return 0; /* only GC0 can be customized */
+
+	write_reg(par, 0xC2,
+		(CURVE(0, 8) << 4) | CURVE(0, 7),
+		(CURVE(0, 10) << 4) | CURVE(0, 9),
+		(CURVE(0, 12) << 4) | CURVE(0, 11),
+		CURVE(0, 2),
+		(CURVE(0, 4) << 4) | CURVE(0, 3),
+		CURVE(0, 5),
+		CURVE(0, 6),
+		(CURVE(0, 1) << 4) | CURVE(0, 0),
+		(CURVE(0, 14) << 2) | CURVE(0, 13));
+
+	write_reg(par, 0xC3,
+		(CURVE(1, 8) << 4) | CURVE(1, 7),
+		(CURVE(1, 10) << 4) | CURVE(1, 9),
+		(CURVE(1, 12) << 4) | CURVE(1, 11),
+		CURVE(1, 2),
+		(CURVE(1, 4) << 4) | CURVE(1, 3),
+		CURVE(1, 5),
+		CURVE(1, 6),
+		(CURVE(1, 1) << 4) | CURVE(1, 0));
+
+	mdelay(10);
+
+	return 0;
+}
+#undef CURVE
+
+
+static struct fbtft_display display = {
+	.regwidth = 8,
+	.width = WIDTH,
+	.height = HEIGHT,
+	.txbuflen = TXBUFLEN,
+	.gamma_num = 2,
+	.gamma_len = 15,
+	.gamma = DEFAULT_GAMMA,
+	.fbtftops = {
+		.init_display = init_display,
+		.set_addr_win = set_addr_win,
+		.set_var = set_var,
+		.set_gamma = set_gamma,
+	},
+};
+FBTFT_REGISTER_DRIVER(DRVNAME, "himax,hx8340bn", &display);
+
+MODULE_ALIAS("spi:" DRVNAME);
+MODULE_ALIAS("platform:" DRVNAME);
+MODULE_ALIAS("spi:hx8340bn");
+MODULE_ALIAS("platform:hx8340bn");
+
+MODULE_DESCRIPTION("FB driver for the HX8340BN LCD Controller");
+MODULE_AUTHOR("Noralf Tronnes");
+MODULE_LICENSE("GPL");