recipes-kernel/linux/linux-ti33x-psp-3.1/adc/0003-AM335x-Add-support-for-pressure-measurement-on-TSC.patch

   1 From 4c5ada67509fc0a47941813900c03b842e6452d1 Mon Sep 17 00:00:00 2001
   2 From: Patil, Rachna <rachna@ti.com>
   3 Date: Fri, 11 Nov 2011 18:28:54 +0530
   4 Subject: [PATCH 3/9] AM335x: Add support for pressure measurement on TSC.
   5
   6 This patch adds support for pressure measurement configurations
   7 on TSC. Along with X and Y co-ordinates pressure is also reported to
   8 the sub-system.
   9
  10 Signed-off-by: Patil, Rachna <rachna@ti.com>
  11 ---
  12  arch/arm/mach-omap2/board-am335xevm.c |    1 +
  13  drivers/input/touchscreen/ti_tscadc.c |   77 +++++++++++++++++++++++++++------
  14  include/linux/input/ti_tscadc.h       |    3 +-
  15  3 files changed, 66 insertions(+), 15 deletions(-)
  16
  17 diff --git a/arch/arm/mach-omap2/board-am335xevm.c b/arch/arm/mach-omap2/board-am335xevm.c
  18 index ecda26a..d7af6dd 100644
  19 --- a/arch/arm/mach-omap2/board-am335xevm.c
  20 +++ b/arch/arm/mach-omap2/board-am335xevm.c
  21 @@ -194,6 +194,7 @@ static struct resource tsc_resources[]  = {
  22
  23  static struct tsc_data am335x_touchscreen_data  = {
  24         .wires  = 4,
  25 +       .x_plate_resistance = 200,
  26  };
  27
  28  static struct platform_device tsc_device = {
  29 diff --git a/drivers/input/touchscreen/ti_tscadc.c b/drivers/input/touchscreen/ti_tscadc.c
  30 index 021db7f..9783435 100644
  31 --- a/drivers/input/touchscreen/ti_tscadc.c
  32 +++ b/drivers/input/touchscreen/ti_tscadc.c
  33 @@ -41,6 +41,10 @@
  34  #define TSCADC_REG_CHARGEDELAY         0x060
  35  #define TSCADC_REG_STEPCONFIG(n)       (0x64 + ((n-1) * 8))
  36  #define TSCADC_REG_STEPDELAY(n)                (0x68 + ((n-1) * 8))
  37 +#define TSCADC_REG_STEPCONFIG13                0x0C4
  38 +#define TSCADC_REG_STEPDELAY13         0x0C8
  39 +#define TSCADC_REG_STEPCONFIG14                0x0CC
  40 +#define TSCADC_REG_STEPDELAY14         0x0D0
  41  #define TSCADC_REG_FIFO0CNT            0xE4
  42  #define TSCADC_REG_FIFO0THR            0xE8
  43  #define TSCADC_REG_FIFO1CNT            0xF0
  44 @@ -50,7 +54,7 @@
  45
  46  /*     Register Bitfields      */
  47  #define TSCADC_IRQWKUP_ENB             BIT(0)
  48 -#define TSCADC_STPENB_STEPENB          0x1fFF
  49 +#define TSCADC_STPENB_STEPENB          0x7FFF
  50  #define TSCADC_IRQENB_FIFO0THRES       BIT(2)
  51  #define TSCADC_IRQENB_FIFO1THRES       BIT(5)
  52  #define TSCADC_IRQENB_PENUP            BIT(9)
  53 @@ -71,10 +75,11 @@
  54  #define TSCADC_STEPCONFIG_IDLE_INP     (1 << 22)
  55  #define TSCADC_STEPCONFIG_OPENDLY      0x018
  56  #define TSCADC_STEPCONFIG_SAMPLEDLY    0x88
  57 -#define TSCADC_STEPCHARGE_INM_SWAP     BIT(16)
  58 -#define TSCADC_STEPCHARGE_INM          BIT(15)
  59 -#define TSCADC_STEPCHARGE_INP_SWAP     BIT(20)
  60 -#define TSCADC_STEPCHARGE_INP          BIT(19)
  61 +#define TSCADC_STEPCONFIG_Z1           (3 << 19)
  62 +#define TSCADC_STEPCHARGE_INM_SWAP     BIT(16)
  63 +#define TSCADC_STEPCHARGE_INM          BIT(15)
  64 +#define TSCADC_STEPCHARGE_INP_SWAP     BIT(20)
  65 +#define TSCADC_STEPCHARGE_INP          BIT(19)
  66  #define TSCADC_STEPCHARGE_RFM          (1 << 23)
  67  #define TSCADC_STEPCHARGE_DELAY                0x1
  68  #define TSCADC_CNTRLREG_TSCSSENB       BIT(0)
  69 @@ -98,6 +103,7 @@ struct tscadc {
  70         struct input_dev        *input;
  71         int                     wires;
  72         int                     analog_input;
  73 +       int                     x_plate_resistance;
  74         struct clk              *clk;
  75         int                     irq;
  76         void __iomem            *tsc_base;
  77 @@ -118,6 +124,7 @@ static void tsc_step_config(struct tscadc *ts_dev)
  78  {
  79         unsigned int    stepconfigx = 0, stepconfigy = 0;
  80         unsigned int    delay, chargeconfig = 0;
  81 +       unsigned int    stepconfigz1 = 0, stepconfigz2 = 0;
  82         int i;
  83
  84         /* Configure the Step registers */
  85 @@ -205,6 +212,18 @@ static void tsc_step_config(struct tscadc *ts_dev)
  86         tscadc_writel(ts_dev, TSCADC_REG_CHARGECONFIG, chargeconfig);
  87         tscadc_writel(ts_dev, TSCADC_REG_CHARGEDELAY, TSCADC_STEPCHARGE_DELAY);
  88
  89 +        /* Configure to calculate pressure */
  90 +       stepconfigz1 = TSCADC_STEPCONFIG_MODE_HWSYNC |
  91 +                               TSCADC_STEPCONFIG_2SAMPLES_AVG |
  92 +                               TSCADC_STEPCONFIG_XNP |
  93 +                               TSCADC_STEPCONFIG_YPN | TSCADC_STEPCONFIG_INM;
  94 +       stepconfigz2 = stepconfigz1 | TSCADC_STEPCONFIG_Z1 |
  95 +                               TSCADC_STEPCONFIG_FIFO1;
  96 +       tscadc_writel(ts_dev, TSCADC_REG_STEPCONFIG13, stepconfigz1);
  97 +       tscadc_writel(ts_dev, TSCADC_REG_STEPDELAY13, delay);
  98 +       tscadc_writel(ts_dev, TSCADC_REG_STEPCONFIG14, stepconfigz2);
  99 +       tscadc_writel(ts_dev, TSCADC_REG_STEPDELAY14, delay);
 100 +
 101         tscadc_writel(ts_dev, TSCADC_REG_SE, TSCADC_STPENB_STEPENB);
 102  }
 103
 104 @@ -235,14 +254,14 @@ static irqreturn_t tscadc_interrupt(int irq, void *dev)
 105         unsigned int            prev_diff_x = ~0, prev_diff_y = ~0;
 106         unsigned int            cur_diff_x = 0, cur_diff_y = 0;
 107         unsigned int            val_x = 0, val_y = 0, diffx = 0, diffy = 0;
 108 +       unsigned int            z1 = 0, z2 = 0, z = 0;
 109
 110         status = tscadc_readl(ts_dev, TSCADC_REG_IRQSTATUS);
 111
 112         if (status & TSCADC_IRQENB_FIFO1THRES) {
 113                 fifo0count = tscadc_readl(ts_dev, TSCADC_REG_FIFO0CNT);
 114                 fifo1count = tscadc_readl(ts_dev, TSCADC_REG_FIFO1CNT);
 115 -
 116 -               for (i = 0; i < fifo0count; i++) {
 117 +               for (i = 0; i < (fifo0count-1); i++) {
 118                         readx1 = tscadc_readl(ts_dev, TSCADC_REG_FIFO0);
 119                         readx1 = readx1 & 0xfff;
 120                         if (readx1 > prev_val_x)
 121 @@ -281,12 +300,39 @@ static irqreturn_t tscadc_interrupt(int irq, void *dev)
 122                 bckup_x = val_x;
 123                 bckup_y = val_y;
 124
 125 -               if (pen == 0) {
 126 -                       if ((diffx < 15) && (diffy < 15)) {
 127 -                               input_report_abs(input_dev, ABS_X, val_x);
 128 -                               input_report_abs(input_dev, ABS_Y, val_y);
 129 -                               input_report_key(input_dev, BTN_TOUCH, 1);
 130 -                               input_sync(input_dev);
 131 +               z1 = ((tscadc_readl(ts_dev, TSCADC_REG_FIFO0)) & 0xfff);
 132 +               z2 = ((tscadc_readl(ts_dev, TSCADC_REG_FIFO1)) & 0xfff);
 133 +
 134 +               if ((z1 != 0) && (z2 != 0)) {
 135 +                       /*
 136 +                        * cal pressure using formula
 137 +                        * Resistance(touch) = x plate resistance *
 138 +                        * x postion/4096 * ((z2 / z1) - 1)
 139 +                        */
 140 +                       z = z2 - z1;
 141 +                       z *= val_x;
 142 +                       z *= ts_dev->x_plate_resistance;
 143 +                       z /= z1;
 144 +                       z = (z + 2047) >> 12;
 145 +
 146 +                       /*
 147 +                        * Sample found inconsistent by debouncing
 148 +                        * or pressure is beyond the maximum.
 149 +                        * Don't report it to user space.
 150 +                        */
 151 +                       if (pen == 0) {
 152 +                               if ((diffx < 15) && (diffy < 15)
 153 +                                               && (z <= MAX_12BIT)) {
 154 +                                       input_report_abs(input_dev, ABS_X,
 155 +                                                       val_x);
 156 +                                       input_report_abs(input_dev, ABS_Y,
 157 +                                                       val_y);
 158 +                                       input_report_abs(input_dev, ABS_PRESSURE,
 159 +                                                       z);
 160 +                                       input_report_key(input_dev, BTN_TOUCH,
 161 +                                                       1);
 162 +                                       input_sync(input_dev);
 163 +                               }
 164                         }
 165                 }
 166                 irqclr |= TSCADC_IRQENB_FIFO1THRES;
 167 @@ -303,6 +349,7 @@ static irqreturn_t tscadc_interrupt(int irq, void *dev)
 168                         bckup_x = 0;
 169                         bckup_y = 0;
 170                         input_report_key(input_dev, BTN_TOUCH, 0);
 171 +                       input_report_abs(input_dev, ABS_PRESSURE, 0);
 172                         input_sync(input_dev);
 173                 } else {
 174                         pen = 0;
 175 @@ -403,6 +450,7 @@ static      int __devinit tscadc_probe(struct platform_device *pdev)
 176
 177         ts_dev->wires = pdata->wires;
 178         ts_dev->analog_input = pdata->analog_input;
 179 +       ts_dev->x_plate_resistance = pdata->x_plate_resistance;
 180
 181         /* Set the control register bits */
 182         ctrl = TSCADC_CNTRLREG_STEPCONFIGWRT |
 183 @@ -430,7 +478,7 @@ static      int __devinit tscadc_probe(struct platform_device *pdev)
 184
 185         tsc_step_config(ts_dev);
 186
 187 -       tscadc_writel(ts_dev, TSCADC_REG_FIFO1THR, 5);
 188 +       tscadc_writel(ts_dev, TSCADC_REG_FIFO1THR, 6);
 189
 190         ctrl |= TSCADC_CNTRLREG_TSCSSENB;
 191         tscadc_writel(ts_dev, TSCADC_REG_CTRL, ctrl);
 192 @@ -443,6 +491,7 @@ static      int __devinit tscadc_probe(struct platform_device *pdev)
 193
 194         input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, 0, 0);
 195         input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, 0, 0);
 196 +       input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_12BIT, 0, 0);
 197
 198         /* register to the input system */
 199         err = input_register_device(input_dev);
 200 diff --git a/include/linux/input/ti_tscadc.h b/include/linux/input/ti_tscadc.h
 201 index b9d9a46..2c547bb 100644
 202 --- a/include/linux/input/ti_tscadc.h
 203 +++ b/include/linux/input/ti_tscadc.h
 204 @@ -11,10 +11,11 @@
 205   *                     XPUL = AN0,YPLL = AN1,XNUR = AN2,
 206   *                     YNLR = AN3, then set this variable to
 207   *                     0.
 208 + * @x_plate_resistance:        X plate resistance.
 209   */
 210
 211  struct tsc_data {
 212         int wires;
 213         int analog_input;
 214 -
 215 +       int x_plate_resistance;
 216  };
 217 --
 218 1.7.2.5
 219