]> git.karo-electronics.de Git - linux-beck.git/commitdiff
iio: adc: at91_adc: Add support for touchscreens without TSMR
authorAlexandre Belloni <alexandre.belloni@free-electrons.com>
Tue, 15 Apr 2014 10:27:59 +0000 (12:27 +0200)
committerNicolas Ferre <nicolas.ferre@atmel.com>
Wed, 7 May 2014 16:28:40 +0000 (18:28 +0200)
Old ADCs, as present on the sam9rl and the sam9g45 don't have a TSMR register
and the touchscreen support should be handled differently.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
arch/arm/mach-at91/include/mach/at91_adc.h
drivers/iio/adc/at91_adc.c
include/linux/platform_data/at91_adc.h

index c287307b9a3ba1a3efcd7b0c09605fef8c4c00e7..7d80396346b2785450aab35561083574d3a8ba8a 100644 (file)
@@ -20,6 +20,9 @@
 #define                AT91_ADC_START          (1 << 1)        /* Start Conversion */
 
 #define AT91_ADC_MR            0x04            /* Mode Register */
+#define                AT91_ADC_TSAMOD         (3 << 0)        /* ADC mode */
+#define                AT91_ADC_TSAMOD_ADC_ONLY_MODE           (0 << 0)        /* ADC Mode */
+#define                AT91_ADC_TSAMOD_TS_ONLY_MODE            (1 << 0)        /* Touch Screen Only Mode */
 #define                AT91_ADC_TRGEN          (1 << 0)        /* Trigger Enable */
 #define                AT91_ADC_TRGSEL         (7 << 1)        /* Trigger Selection */
 #define                        AT91_ADC_TRGSEL_TC0             (0 << 1)
@@ -28,6 +31,7 @@
 #define                        AT91_ADC_TRGSEL_EXTERNAL        (6 << 1)
 #define                AT91_ADC_LOWRES         (1 << 4)        /* Low Resolution */
 #define                AT91_ADC_SLEEP          (1 << 5)        /* Sleep Mode */
+#define                AT91_ADC_PENDET         (1 << 6)        /* Pen contact detection enable */
 #define                AT91_ADC_PRESCAL_9260   (0x3f << 8)     /* Prescalar Rate Selection */
 #define                AT91_ADC_PRESCAL_9G45   (0xff << 8)
 #define                        AT91_ADC_PRESCAL_(x)    ((x) << 8)
 #define                        AT91_ADC_STARTUP_(x)    ((x) << 16)
 #define                AT91_ADC_SHTIM          (0xf  << 24)    /* Sample & Hold Time */
 #define                        AT91_ADC_SHTIM_(x)      ((x) << 24)
+#define                AT91_ADC_PENDBC         (0x0f << 28)    /* Pen Debounce time */
+#define                        AT91_ADC_PENDBC_(x)     ((x) << 28)
+
+#define AT91_ADC_TSR           0x0C
+#define                AT91_ADC_TSR_SHTIM      (0xf  << 24)    /* Sample & Hold Time */
+#define                        AT91_ADC_TSR_SHTIM_(x)  ((x) << 24)
 
 #define AT91_ADC_CHER          0x10            /* Channel Enable Register */
 #define AT91_ADC_CHDR          0x14            /* Channel Disable Register */
@@ -60,6 +70,8 @@
 #define AT91_ADC_IER           0x24            /* Interrupt Enable Register */
 #define AT91_ADC_IDR           0x28            /* Interrupt Disable Register */
 #define AT91_ADC_IMR           0x2C            /* Interrupt Mask Register */
+#define                AT91RL_ADC_IER_PEN      (1 << 20)
+#define                AT91RL_ADC_IER_NOPEN    (1 << 21)
 #define                AT91_ADC_IER_PEN        (1 << 29)
 #define                AT91_ADC_IER_NOPEN      (1 << 30)
 #define                AT91_ADC_IER_XRDY       (1 << 20)
 #define                AT91_ADC_TRGR_TRGPER    (0xffff << 16)
 #define                        AT91_ADC_TRGR_TRGPER_(x)        ((x) << 16)
 #define                AT91_ADC_TRGR_TRGMOD    (0x7 << 0)
+#define                        AT91_ADC_TRGR_NONE              (0 << 0)
 #define                        AT91_ADC_TRGR_MOD_PERIOD_TRIG   (5 << 0)
 
 #endif
index 1beae65aef2c3542b4345b66af273dabd6b41a30..c0e4206e34e5b224a6f85c39cb76577e5811bdf1 100644 (file)
 #define TOUCH_SAMPLE_PERIOD_US         2000    /* 2ms */
 #define TOUCH_PEN_DETECT_DEBOUNCE_US   200
 
+#define MAX_RLPOS_BITS         10
+#define TOUCH_SAMPLE_PERIOD_US_RL      10000   /* 10ms, the SoC can't keep up with 2ms */
+#define TOUCH_SHTIM                    0xa
+
 /**
  * struct at91_adc_reg_desc - Various informations relative to registers
  * @channel_base:      Base offset for the channel data registers
@@ -83,12 +87,6 @@ struct at91_adc_caps {
        struct at91_adc_reg_desc registers;
 };
 
-enum atmel_adc_ts_type {
-       ATMEL_ADC_TOUCHSCREEN_NONE = 0,
-       ATMEL_ADC_TOUCHSCREEN_4WIRE = 4,
-       ATMEL_ADC_TOUCHSCREEN_5WIRE = 5,
-};
-
 struct at91_adc_state {
        struct clk              *adc_clk;
        u16                     *buffer;
@@ -133,6 +131,11 @@ struct at91_adc_state {
 
        u16                     ts_sample_period_val;
        u32                     ts_pressure_threshold;
+       u16                     ts_pendbc;
+
+       bool                    ts_bufferedmeasure;
+       u32                     ts_prev_absx;
+       u32                     ts_prev_absy;
 };
 
 static irqreturn_t at91_adc_trigger_handler(int irq, void *p)
@@ -239,7 +242,72 @@ static int at91_ts_sample(struct at91_adc_state *st)
        return 0;
 }
 
-static irqreturn_t at91_adc_interrupt(int irq, void *private)
+static irqreturn_t at91_adc_rl_interrupt(int irq, void *private)
+{
+       struct iio_dev *idev = private;
+       struct at91_adc_state *st = iio_priv(idev);
+       u32 status = at91_adc_readl(st, st->registers->status_register);
+       unsigned int reg;
+
+       status &= at91_adc_readl(st, AT91_ADC_IMR);
+       if (status & st->registers->drdy_mask)
+               handle_adc_eoc_trigger(irq, idev);
+
+       if (status & AT91RL_ADC_IER_PEN) {
+               /* Disabling pen debounce is required to get a NOPEN irq */
+               reg = at91_adc_readl(st, AT91_ADC_MR);
+               reg &= ~AT91_ADC_PENDBC;
+               at91_adc_writel(st, AT91_ADC_MR, reg);
+
+               at91_adc_writel(st, AT91_ADC_IDR, AT91RL_ADC_IER_PEN);
+               at91_adc_writel(st, AT91_ADC_IER, AT91RL_ADC_IER_NOPEN
+                               | AT91_ADC_EOC(3));
+               /* Set up period trigger for sampling */
+               at91_adc_writel(st, st->registers->trigger_register,
+                       AT91_ADC_TRGR_MOD_PERIOD_TRIG |
+                       AT91_ADC_TRGR_TRGPER_(st->ts_sample_period_val));
+       } else if (status & AT91RL_ADC_IER_NOPEN) {
+               reg = at91_adc_readl(st, AT91_ADC_MR);
+               reg |= AT91_ADC_PENDBC_(st->ts_pendbc) & AT91_ADC_PENDBC;
+               at91_adc_writel(st, AT91_ADC_MR, reg);
+               at91_adc_writel(st, st->registers->trigger_register,
+                       AT91_ADC_TRGR_NONE);
+
+               at91_adc_writel(st, AT91_ADC_IDR, AT91RL_ADC_IER_NOPEN
+                               | AT91_ADC_EOC(3));
+               at91_adc_writel(st, AT91_ADC_IER, AT91RL_ADC_IER_PEN);
+               st->ts_bufferedmeasure = false;
+               input_report_key(st->ts_input, BTN_TOUCH, 0);
+               input_sync(st->ts_input);
+       } else if (status & AT91_ADC_EOC(3)) {
+               /* Conversion finished */
+               if (st->ts_bufferedmeasure) {
+                       /*
+                        * Last measurement is always discarded, since it can
+                        * be erroneous.
+                        * Always report previous measurement
+                        */
+                       input_report_abs(st->ts_input, ABS_X, st->ts_prev_absx);
+                       input_report_abs(st->ts_input, ABS_Y, st->ts_prev_absy);
+                       input_report_key(st->ts_input, BTN_TOUCH, 1);
+                       input_sync(st->ts_input);
+               } else
+                       st->ts_bufferedmeasure = true;
+
+               /* Now make new measurement */
+               st->ts_prev_absx = at91_adc_readl(st, AT91_ADC_CHAN(st, 3))
+                                  << MAX_RLPOS_BITS;
+               st->ts_prev_absx /= at91_adc_readl(st, AT91_ADC_CHAN(st, 2));
+
+               st->ts_prev_absy = at91_adc_readl(st, AT91_ADC_CHAN(st, 1))
+                                  << MAX_RLPOS_BITS;
+               st->ts_prev_absy /= at91_adc_readl(st, AT91_ADC_CHAN(st, 0));
+       }
+
+       return IRQ_HANDLED;
+}
+
+static irqreturn_t at91_adc_9x5_interrupt(int irq, void *private)
 {
        struct iio_dev *idev = private;
        struct at91_adc_state *st = iio_priv(idev);
@@ -672,6 +740,8 @@ static int at91_adc_probe_dt_ts(struct device_node *node,
                return -EINVAL;
        }
 
+       if (!st->caps->has_tsmr)
+               return 0;
        prop = 0;
        of_property_read_u32(node, "atmel,adc-ts-pressure-threshold", &prop);
        st->ts_pressure_threshold = prop;
@@ -795,6 +865,7 @@ static int at91_adc_probe_pdata(struct at91_adc_state *st,
        st->trigger_number = pdata->trigger_number;
        st->trigger_list = pdata->trigger_list;
        st->registers = &st->caps->registers;
+       st->touchscreen_type = pdata->touchscreen_type;
 
        return 0;
 }
@@ -809,7 +880,10 @@ static int atmel_ts_open(struct input_dev *dev)
 {
        struct at91_adc_state *st = input_get_drvdata(dev);
 
-       at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_PEN);
+       if (st->caps->has_tsmr)
+               at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_PEN);
+       else
+               at91_adc_writel(st, AT91_ADC_IER, AT91RL_ADC_IER_PEN);
        return 0;
 }
 
@@ -817,45 +891,61 @@ static void atmel_ts_close(struct input_dev *dev)
 {
        struct at91_adc_state *st = input_get_drvdata(dev);
 
-       at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_PEN);
+       if (st->caps->has_tsmr)
+               at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_PEN);
+       else
+               at91_adc_writel(st, AT91_ADC_IDR, AT91RL_ADC_IER_PEN);
 }
 
 static int at91_ts_hw_init(struct at91_adc_state *st, u32 adc_clk_khz)
 {
-       u32 reg = 0, pendbc;
+       u32 reg = 0;
        int i = 0;
 
-       if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_4WIRE)
-               reg = AT91_ADC_TSMR_TSMODE_4WIRE_PRESS;
-       else
-               reg = AT91_ADC_TSMR_TSMODE_5WIRE;
-
        /* a Pen Detect Debounce Time is necessary for the ADC Touch to avoid
         * pen detect noise.
         * The formula is : Pen Detect Debounce Time = (2 ^ pendbc) / ADCClock
         */
-       pendbc = round_up(TOUCH_PEN_DETECT_DEBOUNCE_US * adc_clk_khz / 1000, 1);
+       st->ts_pendbc = round_up(TOUCH_PEN_DETECT_DEBOUNCE_US * adc_clk_khz /
+                                1000, 1);
 
-       while (pendbc >> ++i)
+       while (st->ts_pendbc >> ++i)
                ;       /* Empty! Find the shift offset */
-       if (abs(pendbc - (1 << i)) < abs(pendbc - (1 << (i - 1))))
-               pendbc = i;
+       if (abs(st->ts_pendbc - (1 << i)) < abs(st->ts_pendbc - (1 << (i - 1))))
+               st->ts_pendbc = i;
        else
-               pendbc = i - 1;
+               st->ts_pendbc = i - 1;
 
-       if (st->caps->has_tsmr) {
-               reg |= AT91_ADC_TSMR_TSAV_(st->caps->ts_filter_average)
-                               & AT91_ADC_TSMR_TSAV;
-               reg |= AT91_ADC_TSMR_PENDBC_(pendbc) & AT91_ADC_TSMR_PENDBC;
-               reg |= AT91_ADC_TSMR_NOTSDMA;
-               reg |= AT91_ADC_TSMR_PENDET_ENA;
-               reg |= 0x03 << 8;       /* TSFREQ, need bigger than TSAV */
-
-               at91_adc_writel(st, AT91_ADC_TSMR, reg);
-       } else {
-               /* TODO: for 9g45 which has no TSMR */
+       if (!st->caps->has_tsmr) {
+               reg = at91_adc_readl(st, AT91_ADC_MR);
+               reg |= AT91_ADC_TSAMOD_TS_ONLY_MODE | AT91_ADC_PENDET;
+
+               reg |= AT91_ADC_PENDBC_(st->ts_pendbc) & AT91_ADC_PENDBC;
+               at91_adc_writel(st, AT91_ADC_MR, reg);
+
+               reg = AT91_ADC_TSR_SHTIM_(TOUCH_SHTIM) & AT91_ADC_TSR_SHTIM;
+               at91_adc_writel(st, AT91_ADC_TSR, reg);
+
+               st->ts_sample_period_val = round_up((TOUCH_SAMPLE_PERIOD_US_RL *
+                                                   adc_clk_khz / 1000) - 1, 1);
+
+               return 0;
        }
 
+       if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_4WIRE)
+               reg = AT91_ADC_TSMR_TSMODE_4WIRE_PRESS;
+       else
+               reg = AT91_ADC_TSMR_TSMODE_5WIRE;
+
+       reg |= AT91_ADC_TSMR_TSAV_(st->caps->ts_filter_average)
+              & AT91_ADC_TSMR_TSAV;
+       reg |= AT91_ADC_TSMR_PENDBC_(st->ts_pendbc) & AT91_ADC_TSMR_PENDBC;
+       reg |= AT91_ADC_TSMR_NOTSDMA;
+       reg |= AT91_ADC_TSMR_PENDET_ENA;
+       reg |= 0x03 << 8;       /* TSFREQ, needs to be bigger than TSAV */
+
+       at91_adc_writel(st, AT91_ADC_TSMR, reg);
+
        /* Change adc internal resistor value for better pen detection,
         * default value is 100 kOhm.
         * 0 = 200 kOhm, 1 = 150 kOhm, 2 = 100 kOhm, 3 = 50 kOhm
@@ -864,7 +954,7 @@ static int at91_ts_hw_init(struct at91_adc_state *st, u32 adc_clk_khz)
        at91_adc_writel(st, AT91_ADC_ACR, st->caps->ts_pen_detect_sensitivity
                        & AT91_ADC_ACR_PENDETSENS);
 
-       /* Sample Peroid Time = (TRGPER + 1) / ADCClock */
+       /* Sample Period Time = (TRGPER + 1) / ADCClock */
        st->ts_sample_period_val = round_up((TOUCH_SAMPLE_PERIOD_US *
                        adc_clk_khz / 1000) - 1, 1);
 
@@ -893,17 +983,37 @@ static int at91_ts_register(struct at91_adc_state *st,
        __set_bit(EV_ABS, input->evbit);
        __set_bit(EV_KEY, input->evbit);
        __set_bit(BTN_TOUCH, input->keybit);
-       input_set_abs_params(input, ABS_X, 0, (1 << MAX_POS_BITS) - 1, 0, 0);
-       input_set_abs_params(input, ABS_Y, 0, (1 << MAX_POS_BITS) - 1, 0, 0);
-       input_set_abs_params(input, ABS_PRESSURE, 0, 0xffffff, 0, 0);
+       if (st->caps->has_tsmr) {
+               input_set_abs_params(input, ABS_X, 0, (1 << MAX_POS_BITS) - 1,
+                                    0, 0);
+               input_set_abs_params(input, ABS_Y, 0, (1 << MAX_POS_BITS) - 1,
+                                    0, 0);
+               input_set_abs_params(input, ABS_PRESSURE, 0, 0xffffff, 0, 0);
+       } else {
+               if (st->touchscreen_type != ATMEL_ADC_TOUCHSCREEN_4WIRE) {
+                       dev_err(&pdev->dev,
+                               "This touchscreen controller only support 4 wires\n");
+                       ret = -EINVAL;
+                       goto err;
+               }
+
+               input_set_abs_params(input, ABS_X, 0, (1 << MAX_RLPOS_BITS) - 1,
+                                    0, 0);
+               input_set_abs_params(input, ABS_Y, 0, (1 << MAX_RLPOS_BITS) - 1,
+                                    0, 0);
+       }
 
        st->ts_input = input;
        input_set_drvdata(input, st);
 
        ret = input_register_device(input);
        if (ret)
-               input_free_device(st->ts_input);
+               goto err;
+
+       return ret;
 
+err:
+       input_free_device(st->ts_input);
        return ret;
 }
 
@@ -962,11 +1072,13 @@ static int at91_adc_probe(struct platform_device *pdev)
         */
        at91_adc_writel(st, AT91_ADC_CR, AT91_ADC_SWRST);
        at91_adc_writel(st, AT91_ADC_IDR, 0xFFFFFFFF);
-       ret = request_irq(st->irq,
-                         at91_adc_interrupt,
-                         0,
-                         pdev->dev.driver->name,
-                         idev);
+
+       if (st->caps->has_tsmr)
+               ret = request_irq(st->irq, at91_adc_9x5_interrupt, 0,
+                                 pdev->dev.driver->name, idev);
+       else
+               ret = request_irq(st->irq, at91_adc_rl_interrupt, 0,
+                                 pdev->dev.driver->name, idev);
        if (ret) {
                dev_err(&pdev->dev, "Failed to allocate IRQ.\n");
                return ret;
@@ -1070,12 +1182,6 @@ static int at91_adc_probe(struct platform_device *pdev)
                        goto error_disable_adc_clk;
                }
        } else {
-               if (!st->caps->has_tsmr) {
-                       dev_err(&pdev->dev, "We don't support non-TSMR adc\n");
-                       ret = -ENODEV;
-                       goto error_disable_adc_clk;
-               }
-
                ret = at91_ts_register(st, pdev);
                if (ret)
                        goto error_disable_adc_clk;
index fcf73879dbfe8cfa3aad6d41f9ef087b85e1425d..7819fc787731814bda7c7374cafb657972049030 100644 (file)
@@ -7,6 +7,12 @@
 #ifndef _AT91_ADC_H_
 #define _AT91_ADC_H_
 
+enum atmel_adc_ts_type {
+       ATMEL_ADC_TOUCHSCREEN_NONE = 0,
+       ATMEL_ADC_TOUCHSCREEN_4WIRE = 4,
+       ATMEL_ADC_TOUCHSCREEN_5WIRE = 5,
+};
+
 /**
  * struct at91_adc_trigger - description of triggers
  * @name:              name of the trigger advertised to the user
@@ -28,6 +34,7 @@ struct at91_adc_trigger {
  * @trigger_number:            Number of triggers available in the ADC
  * @use_external_triggers:     does the board has external triggers availables
  * @vref:                      Reference voltage for the ADC in millivolts
+ * @touchscreen_type:          If a touchscreen is connected, its type (4 or 5 wires)
  */
 struct at91_adc_data {
        unsigned long                   channels_used;
@@ -36,6 +43,7 @@ struct at91_adc_data {
        u8                              trigger_number;
        bool                            use_external_triggers;
        u16                             vref;
+       enum atmel_adc_ts_type          touchscreen_type;
 };
 
 extern void __init at91_add_device_adc(struct at91_adc_data *data);