drivers/input/touchscreen/omap/ts_hx.c

   1 /*
   2  * input/touchscreen/omap/ts_hx.c
   3  * touchscreen support for OMAP H3 and H2  boards
   4  *
   5  * Copyright (c) 2002 MontaVista Software Inc.
   6  * Copyright (c) 2004 Texas Instruments, Inc.
   7  *
   8  * Assembled using driver code copyright the companies above.
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  23  *
  24  * History:
  25  * 9/12/2004    Srinath Modified and integrated  H2 and H3 code
  26  *
  27  */
  28
  29 #include <linux/input.h>
  30 #include <linux/device.h>
  31 #include <asm/mach-types.h>
  32 #include <asm/arch/gpio.h>
  33 #include <asm/arch/mux.h>
  34 #include <asm/arch/hardware.h>
  35 #include <asm/hardware/tsc2101.h>
  36
  37 #include "../drivers/ssi/omap-tsc2101.h"
  38 #include "omap_ts.h"
  39
  40 #define H2_GPIO_NUM             4
  41 #define H3_GPIO_NUM             48
  42
  43 #define OMAP_TSC2101_XRES                      500
  44 #define TOUCHSCREEN_DATA_REGISTERS_PAGE  0x0
  45 #define TOUCHSCREEN_CONTROL_REGISTERS_PAGE      0x1
  46 #define OMAP_TSC2101_READ_MAX              0x4
  47 #define TSC2101_GETSTATUS(ret)            (((ret) >> 11) & 0x1)
  48 #define TSC2101_MASKVAL                  0xFFF
  49 #define TSC2101_PRESSUREVAL(x)            ((x) << 12)
  50
  51 static int hx_ts_penup(void);
  52 static int hx_ts_probe(struct omap_ts_t *ts);
  53 static void hx_ts_read(u16 * data);
  54 static void hx_ts_enable(void);
  55 static void hx_ts_disable(void);
  56 #ifdef  MODULE
  57 static void hx_ts_remove(void);
  58 #endif
  59
  60 struct ts_device hx_ts = {
  61         .probe          = hx_ts_probe,
  62         .read           = hx_ts_read,
  63         .enable         = hx_ts_enable,
  64         .disable        = hx_ts_disable,
  65         .remove         = __exit_p(hx_ts_remove),
  66         .penup          = hx_ts_penup,
  67 };
  68
  69 static int hx_ts_penup(void)
  70 {
  71         int ret = 0;
  72         /* Read the status register */
  73         ret = omap_tsc2101_read(TOUCHSCREEN_CONTROL_REGISTERS_PAGE,
  74                                 TSC2101_TS_STATUS);
  75         /* Check for availability of data in status register */
  76         ret = TSC2101_GETSTATUS(ret);
  77         return !ret;
  78
  79 }
  80
  81 static int __init hx_ts_probe(struct omap_ts_t *ts)
  82 {
  83         unsigned        gpio;
  84
  85         if (machine_is_omap_h2()) {
  86                 gpio = H2_GPIO_NUM;
  87                 omap_cfg_reg(P20_1610_GPIO4);
  88         } else if (machine_is_omap_h3()) {
  89                 gpio = H3_GPIO_NUM;
  90                 omap_cfg_reg(W19_1610_GPIO48);
  91         } else
  92                 return -ENODEV;
  93
  94         ts->irq = OMAP_GPIO_IRQ(gpio);
  95         if (omap_request_gpio(gpio) != 0) {
  96                 printk(KERN_ERR "hX_ts_init.c: Could not reserve GPIO!\n");
  97                 return -EINVAL;
  98         };
  99
 100         omap_set_gpio_direction(gpio, 1);
 101         ts->irq_type = IRQF_TRIGGER_FALLING;
 102         return 0;
 103 }
 104
 105 static void hx_ts_read(u16 * values)
 106 {
 107         s32 t, p = 0;
 108         int i;
 109
 110         /* Read X, Y, Z1 and Z2 */
 111         omap_tsc2101_reads(TOUCHSCREEN_DATA_REGISTERS_PAGE, TSC2101_TS_X,
 112                            values, OMAP_TSC2101_READ_MAX);
 113
 114         for (i = 0; i < OMAP_TSC2101_READ_MAX; i++)
 115                 values[i] &= TSC2101_MASKVAL;
 116
 117         /* Calculate Pressure */
 118         if (values[TSC2101_TS_Z1] != 0) {
 119                 t = ((OMAP_TSC2101_XRES * values[TSC2101_TS_X]) *
 120                      (values[TSC2101_TS_Z2] - values[TSC2101_TS_Z1]));
 121                 p = t / (u32) (TSC2101_PRESSUREVAL(values[TSC2101_TS_Z1]));
 122                 if (p < 0)
 123                         p = 0;
 124         }
 125
 126         values[TSC2101_TS_Z1] = p;
 127 }
 128
 129 static void hx_ts_enable(void)
 130 {
 131         int ret = omap_tsc2101_enable();
 132         if (ret) {
 133                 printk(KERN_ERR "FAILED TO INITIALIZE TSC CODEC\n");
 134                 return;
 135         }
 136
 137         /* PINTDAV is data available only */
 138         omap_tsc2101_write(TOUCHSCREEN_CONTROL_REGISTERS_PAGE,
 139                            TSC2101_TS_STATUS, TSC2101_DATA_AVAILABLE);
 140         /* disable buffer mode */
 141         omap_tsc2101_write(TOUCHSCREEN_CONTROL_REGISTERS_PAGE,
 142                            TSC2101_TS_BUFFER_CTRL, TSC2101_BUFFERMODE_DISABLE);
 143         /* use internal reference, 100 usec power-up delay,
 144          *        * power down between conversions, 1.25V internal reference */
 145         omap_tsc2101_write(TOUCHSCREEN_CONTROL_REGISTERS_PAGE,
 146                            TSC2101_TS_REF_CTRL, TSC2101_REF_POWERUP);
 147         /* enable touch detection, 84usec precharge time, 32 usec sense time */
 148         omap_tsc2101_write(TOUCHSCREEN_CONTROL_REGISTERS_PAGE,
 149                            TSC2101_TS_CONFIG_CTRL, TSC2101_ENABLE_TOUCHDETECT);
 150         /* 3 msec conversion delays  */
 151         omap_tsc2101_write(TOUCHSCREEN_CONTROL_REGISTERS_PAGE,
 152                            TSC2101_TS_PROG_DELAY, TSC2101_PRG_DELAY);
 153         /*
 154          * TSC2101-controlled conversions
 155          * 12-bit samples
 156          * continuous X,Y,Z1,Z2 scan mode
 157          * average (mean) 4 samples per coordinate
 158          * 1 MHz internal conversion clock
 159          * 500 usec panel voltage stabilization delay
 160          */
 161         omap_tsc2101_write(TOUCHSCREEN_CONTROL_REGISTERS_PAGE,
 162                            TSC2101_TS_ADC_CTRL, TSC2101_ADC_CONTROL);
 163
 164         return;
 165
 166 }
 167
 168 static void hx_ts_disable(void)
 169 {
 170         /* stop conversions and power down */
 171         omap_tsc2101_write(TOUCHSCREEN_CONTROL_REGISTERS_PAGE,
 172                            TSC2101_TS_ADC_CTRL, TSC2101_ADC_POWERDOWN);
 173         omap_tsc2101_disable();
 174 }
 175
 176 #ifdef  MODULE
 177 static void __exit hx_ts_remove(void)
 178 {
 179         if (machine_is_omap_h2())
 180                 omap_free_gpio(H2_GPIO_NUM);
 181         else if (machine_is_omap_h3())
 182                 omap_free_gpio(H3_GPIO_NUM);
 183 }
 184 #endif