drivers/staging/fbtft/fb_ili9325.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * FB driver for the ILI9325 LCD Controller
   4  *
   5  * Copyright (C) 2013 Noralf Tronnes
   6  *
   7  * Based on ili9325.c by Jeroen Domburg
   8  */
   9
  10 #include <linux/module.h>
  11 #include <linux/kernel.h>
  12 #include <linux/init.h>
  13 #include <linux/gpio/consumer.h>
  14 #include <linux/delay.h>
  15
  16 #include "fbtft.h"
  17
  18 #define DRVNAME         "fb_ili9325"
  19 #define WIDTH           240
  20 #define HEIGHT          320
  21 #define BPP             16
  22 #define FPS             20
  23 #define DEFAULT_GAMMA   "0F 00 7 2 0 0 6 5 4 1\n" \
  24                         "04 16 2 7 6 3 2 1 7 7"
  25
  26 static unsigned int bt = 6; /* VGL=Vci*4 , VGH=Vci*4 */
  27 module_param(bt, uint, 0000);
  28 MODULE_PARM_DESC(bt, "Sets the factor used in the step-up circuits");
  29
  30 static unsigned int vc = 0x03; /* Vci1=Vci*0.80 */
  31 module_param(vc, uint, 0000);
  32 MODULE_PARM_DESC(vc, "Sets the ratio factor of Vci to generate the reference voltages Vci1");
  33
  34 static unsigned int vrh = 0x0d; /* VREG1OUT=Vci*1.85 */
  35 module_param(vrh, uint, 0000);
  36 MODULE_PARM_DESC(vrh, "Set the amplifying rate (1.6 ~ 1.9) of Vci applied to output the VREG1OUT");
  37
  38 static unsigned int vdv = 0x12; /* VCOMH amplitude=VREG1OUT*0.98 */
  39 module_param(vdv, uint, 0000);
  40 MODULE_PARM_DESC(vdv, "Select the factor of VREG1OUT to set the amplitude of Vcom");
  41
  42 static unsigned int vcm = 0x0a; /* VCOMH=VREG1OUT*0.735 */
  43 module_param(vcm, uint, 0000);
  44 MODULE_PARM_DESC(vcm, "Set the internal VcomH voltage");
  45
  46 /*
  47  * Verify that this configuration is within the Voltage limits
  48  *
  49  * Display module configuration: Vcc = IOVcc = Vci = 3.3V
  50  *
  51  * Voltages
  52  * ----------
  53  * Vci                                =   3.3
  54  * Vci1           =  Vci * 0.80       =   2.64
  55  * DDVDH          =  Vci1 * 2         =   5.28
  56  * VCL            = -Vci1             =  -2.64
  57  * VREG1OUT       =  Vci * 1.85       =   4.88
  58  * VCOMH          =  VREG1OUT * 0.735 =   3.59
  59  * VCOM amplitude =  VREG1OUT * 0.98  =   4.79
  60  * VGH            =  Vci * 4          =  13.2
  61  * VGL            = -Vci * 4          = -13.2
  62  *
  63  * Limits
  64  * --------
  65  * Power supplies
  66  * 1.65 < IOVcc < 3.30   =>  1.65 < 3.3 < 3.30
  67  * 2.40 < Vcc   < 3.30   =>  2.40 < 3.3 < 3.30
  68  * 2.50 < Vci   < 3.30   =>  2.50 < 3.3 < 3.30
  69  *
  70  * Source/VCOM power supply voltage
  71  *  4.50 < DDVDH < 6.0   =>  4.50 <  5.28 <  6.0
  72  * -3.0  < VCL   < -2.0  =>  -3.0 < -2.64 < -2.0
  73  * VCI - VCL < 6.0       =>  5.94 < 6.0
  74  *
  75  * Gate driver output voltage
  76  *  10  < VGH   < 20     =>   10 <  13.2  < 20
  77  * -15  < VGL   < -5     =>  -15 < -13.2  < -5
  78  * VGH - VGL < 32        =>   26.4 < 32
  79  *
  80  * VCOM driver output voltage
  81  * VCOMH - VCOML < 6.0   =>  4.79 < 6.0
  82  */
  83
  84 static int init_display(struct fbtft_par *par)
  85 {
  86         par->fbtftops.reset(par);
  87
  88         if (par->gpio.cs)
  89                 gpiod_set_value(par->gpio.cs, 0);  /* Activate chip */
  90
  91         bt &= 0x07;
  92         vc &= 0x07;
  93         vrh &= 0x0f;
  94         vdv &= 0x1f;
  95         vcm &= 0x3f;
  96
  97         /* Initialization sequence from ILI9325 Application Notes */
  98
  99         /* ----------- Start Initial Sequence ----------- */
 100         write_reg(par, 0x00E3, 0x3008); /* Set internal timing */
 101         write_reg(par, 0x00E7, 0x0012); /* Set internal timing */
 102         write_reg(par, 0x00EF, 0x1231); /* Set internal timing */
 103         write_reg(par, 0x0001, 0x0100); /* set SS and SM bit */
 104         write_reg(par, 0x0002, 0x0700); /* set 1 line inversion */
 105         write_reg(par, 0x0004, 0x0000); /* Resize register */
 106         write_reg(par, 0x0008, 0x0207); /* set the back porch and front porch */
 107         write_reg(par, 0x0009, 0x0000); /* set non-display area refresh cycle */
 108         write_reg(par, 0x000A, 0x0000); /* FMARK function */
 109         write_reg(par, 0x000C, 0x0000); /* RGB interface setting */
 110         write_reg(par, 0x000D, 0x0000); /* Frame marker Position */
 111         write_reg(par, 0x000F, 0x0000); /* RGB interface polarity */
 112
 113         /* ----------- Power On sequence ----------- */
 114         write_reg(par, 0x0010, 0x0000); /* SAP, BT[3:0], AP, DSTB, SLP, STB */
 115         write_reg(par, 0x0011, 0x0007); /* DC1[2:0], DC0[2:0], VC[2:0] */
 116         write_reg(par, 0x0012, 0x0000); /* VREG1OUT voltage */
 117         write_reg(par, 0x0013, 0x0000); /* VDV[4:0] for VCOM amplitude */
 118         mdelay(200); /* Dis-charge capacitor power voltage */
 119         write_reg(par, 0x0010, /* SAP, BT[3:0], AP, DSTB, SLP, STB */
 120                 BIT(12) | (bt << 8) | BIT(7) | BIT(4));
 121         write_reg(par, 0x0011, 0x220 | vc); /* DC1[2:0], DC0[2:0], VC[2:0] */
 122         mdelay(50); /* Delay 50ms */
 123         write_reg(par, 0x0012, vrh); /* Internal reference voltage= Vci; */
 124         mdelay(50); /* Delay 50ms */
 125         write_reg(par, 0x0013, vdv << 8); /* Set VDV[4:0] for VCOM amplitude */
 126         write_reg(par, 0x0029, vcm); /* Set VCM[5:0] for VCOMH */
 127         write_reg(par, 0x002B, 0x000C); /* Set Frame Rate */
 128         mdelay(50); /* Delay 50ms */
 129         write_reg(par, 0x0020, 0x0000); /* GRAM horizontal Address */
 130         write_reg(par, 0x0021, 0x0000); /* GRAM Vertical Address */
 131
 132         /*------------------ Set GRAM area --------------- */
 133         write_reg(par, 0x0050, 0x0000); /* Horizontal GRAM Start Address */
 134         write_reg(par, 0x0051, 0x00EF); /* Horizontal GRAM End Address */
 135         write_reg(par, 0x0052, 0x0000); /* Vertical GRAM Start Address */
 136         write_reg(par, 0x0053, 0x013F); /* Vertical GRAM Start Address */
 137         write_reg(par, 0x0060, 0xA700); /* Gate Scan Line */
 138         write_reg(par, 0x0061, 0x0001); /* NDL,VLE, REV */
 139         write_reg(par, 0x006A, 0x0000); /* set scrolling line */
 140
 141         /*-------------- Partial Display Control --------- */
 142         write_reg(par, 0x0080, 0x0000);
 143         write_reg(par, 0x0081, 0x0000);
 144         write_reg(par, 0x0082, 0x0000);
 145         write_reg(par, 0x0083, 0x0000);
 146         write_reg(par, 0x0084, 0x0000);
 147         write_reg(par, 0x0085, 0x0000);
 148
 149         /*-------------- Panel Control ------------------- */
 150         write_reg(par, 0x0090, 0x0010);
 151         write_reg(par, 0x0092, 0x0600);
 152         write_reg(par, 0x0007, 0x0133); /* 262K color and display ON */
 153
 154         return 0;
 155 }
 156
 157 static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye)
 158 {
 159         switch (par->info->var.rotate) {
 160         /* R20h = Horizontal GRAM Start Address */
 161         /* R21h = Vertical GRAM Start Address */
 162         case 0:
 163                 write_reg(par, 0x0020, xs);
 164                 write_reg(par, 0x0021, ys);
 165                 break;
 166         case 180:
 167                 write_reg(par, 0x0020, WIDTH - 1 - xs);
 168                 write_reg(par, 0x0021, HEIGHT - 1 - ys);
 169                 break;
 170         case 270:
 171                 write_reg(par, 0x0020, WIDTH - 1 - ys);
 172                 write_reg(par, 0x0021, xs);
 173                 break;
 174         case 90:
 175                 write_reg(par, 0x0020, ys);
 176                 write_reg(par, 0x0021, HEIGHT - 1 - xs);
 177                 break;
 178         }
 179         write_reg(par, 0x0022); /* Write Data to GRAM */
 180 }
 181
 182 static int set_var(struct fbtft_par *par)
 183 {
 184         switch (par->info->var.rotate) {
 185         /* AM: GRAM update direction */
 186         case 0:
 187                 write_reg(par, 0x03, 0x0030 | (par->bgr << 12));
 188                 break;
 189         case 180:
 190                 write_reg(par, 0x03, 0x0000 | (par->bgr << 12));
 191                 break;
 192         case 270:
 193                 write_reg(par, 0x03, 0x0028 | (par->bgr << 12));
 194                 break;
 195         case 90:
 196                 write_reg(par, 0x03, 0x0018 | (par->bgr << 12));
 197                 break;
 198         }
 199
 200         return 0;
 201 }
 202
 203 /*
 204  * Gamma string format:
 205  *  VRP0 VRP1 RP0 RP1 KP0 KP1 KP2 KP3 KP4 KP5
 206  *  VRN0 VRN1 RN0 RN1 KN0 KN1 KN2 KN3 KN4 KN5
 207  */
 208 #define CURVE(num, idx)  curves[(num) * par->gamma.num_values + (idx)]
 209 static int set_gamma(struct fbtft_par *par, u32 *curves)
 210 {
 211         unsigned long mask[] = {
 212                 0x1f, 0x1f, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
 213                 0x1f, 0x1f, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
 214         };
 215         int i, j;
 216
 217         /* apply mask */
 218         for (i = 0; i < 2; i++)
 219                 for (j = 0; j < 10; j++)
 220                         CURVE(i, j) &= mask[i * par->gamma.num_values + j];
 221
 222         write_reg(par, 0x0030, CURVE(0, 5) << 8 | CURVE(0, 4));
 223         write_reg(par, 0x0031, CURVE(0, 7) << 8 | CURVE(0, 6));
 224         write_reg(par, 0x0032, CURVE(0, 9) << 8 | CURVE(0, 8));
 225         write_reg(par, 0x0035, CURVE(0, 3) << 8 | CURVE(0, 2));
 226         write_reg(par, 0x0036, CURVE(0, 1) << 8 | CURVE(0, 0));
 227
 228         write_reg(par, 0x0037, CURVE(1, 5) << 8 | CURVE(1, 4));
 229         write_reg(par, 0x0038, CURVE(1, 7) << 8 | CURVE(1, 6));
 230         write_reg(par, 0x0039, CURVE(1, 9) << 8 | CURVE(1, 8));
 231         write_reg(par, 0x003C, CURVE(1, 3) << 8 | CURVE(1, 2));
 232         write_reg(par, 0x003D, CURVE(1, 1) << 8 | CURVE(1, 0));
 233
 234         return 0;
 235 }
 236
 237 #undef CURVE
 238
 239 static struct fbtft_display display = {
 240         .regwidth = 16,
 241         .width = WIDTH,
 242         .height = HEIGHT,
 243         .bpp = BPP,
 244         .fps = FPS,
 245         .gamma_num = 2,
 246         .gamma_len = 10,
 247         .gamma = DEFAULT_GAMMA,
 248         .fbtftops = {
 249                 .init_display = init_display,
 250                 .set_addr_win = set_addr_win,
 251                 .set_var = set_var,
 252                 .set_gamma = set_gamma,
 253         },
 254 };
 255
 256 FBTFT_REGISTER_DRIVER(DRVNAME, "ilitek,ili9325", &display);
 257
 258 MODULE_ALIAS("spi:" DRVNAME);
 259 MODULE_ALIAS("platform:" DRVNAME);
 260 MODULE_ALIAS("spi:ili9325");
 261 MODULE_ALIAS("platform:ili9325");
 262
 263 MODULE_DESCRIPTION("FB driver for the ILI9325 LCD Controller");
 264 MODULE_AUTHOR("Noralf Tronnes");
 265 MODULE_LICENSE("GPL");