Optional trigger Nodes:
- Required properties:
diff --git a/arch/arm/mach-at91/include/mach/at91_adc.h b/arch/arm/mach-at91/include/mach/at91_adc.h
index ab273ee..6d6cc14 100644
--- a/arch/arm/mach-at91/include/mach/at91_adc.h
+++ b/arch/arm/mach-at91/include/mach/at91_adc.h
@@ -57,10 +57,44 @@
#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 AT91_ADC_IER_PEN (1 << 29)
+#define AT91_ADC_IER_NOPEN (1 << 30)
+#define AT91_ADC_IER_XRDY (1 << 20)
+#define AT91_ADC_IER_YRDY (1 << 21)
+#define AT91_ADC_IER_PRDY (1 << 22)
+#define AT91_ADC_ISR_PENS (1 << 31)
#define AT91_ADC_CHR(n) (0x30 + ((n) * 4)) /* Channel Data Register N */
#define AT91_ADC_DATA (0x3ff)
+#define AT91_ADC_ACR 0x94 /* Analog Control Register */
+#define AT91_ADC_ACR_PENDETSENS (0x3 << 0) /* pull-up resistor */
+
+#define AT91_ADC_TSMR 0xB0
+#define AT91_ADC_TSMR_TSMODE (3 << 0) /* Touch Screen Mode */
+#define AT91_ADC_TSMR_TSMODE_NONE (0 << 0)
+#define AT91_ADC_TSMR_TSMODE_4WIRE_NO_PRESS (1 << 0)
+#define AT91_ADC_TSMR_TSMODE_4WIRE_PRESS (2 << 0)
+#define AT91_ADC_TSMR_TSMODE_5WIRE (3 << 0)
+#define AT91_ADC_TSMR_TSAV (3 << 4) /* Averages samples */
+#define AT91_ADC_TSMR_TSAV_(x) ((x) << 4)
+#define AT91_ADC_TSMR_SCTIM (0x0f << 16) /* Switch closure time */
+#define AT91_ADC_TSMR_PENDBC (0x0f << 28) /* Pen Debounce time */
+#define AT91_ADC_TSMR_PENDBC_(x) ((x) << 28)
+#define AT91_ADC_TSMR_NOTSDMA (1 << 22) /* No Touchscreen DMA */
+#define AT91_ADC_TSMR_PENDET_DIS (0 << 24) /* Pen contact detection disable */
+#define AT91_ADC_TSMR_PENDET_ENA (1 << 24) /* Pen contact detection enable */
+
+#define AT91_ADC_TSXPOSR 0xB4
+#define AT91_ADC_TSYPOSR 0xB8
+#define AT91_ADC_TSPRESSR 0xBC
+
#define AT91_ADC_VERSION 0xFC
+/* Trigger Register bit field */
+#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_MOD_PERIOD_TRIG (5 << 0)
+
#endif
diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c
index 8f1386f..ffc0e42 100644
--- a/drivers/iio/adc/at91_adc.c
+++ b/drivers/iio/adc/at91_adc.c
@@ -11,6 +11,7 @@
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/io.h>
+#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
@@ -39,12 +40,24 @@
#define at91_adc_writel(st, reg, val) \
(writel_relaxed(val, st->reg_base + reg))
+#define DRIVER_NAME "at91_adc"
+#define MAX_POS_BITS 12
+
+#define ZTHRESHOLD 9000
+
struct at91_adc_caps {
+ bool has_12bits_xy; /* true means use 12 bits. Otherwise 10 bits */
bool has_tsmr; /* only at91sam9x5, sama5d3 have TSMR reg */
u32 mr_prescal_mask;
u32 mr_startup_mask;
};
+enum atmel_adc_ts_type {
+ ATMEL_ADC_TOUCHSCREEN_NONE = 0,
+ ATMEL_ADC_TOUCHSCREEN_4WIRE,
+ ATMEL_ADC_TOUCHSCREEN_5WIRE,
+};
+
struct at91_adc_state {
struct clk *adc_clk;
u32 adc_clk_rate;
@@ -70,6 +83,29 @@ struct at91_adc_state {
bool low_res; /* the resolution corresponds to the lowest one */
wait_queue_head_t wq_data_avail;
struct at91_adc_caps caps;
+
+ /*
+ * Following ADC channels are shared by touchscreen:
+ *
+ * CH0 -- Touch screen XP/UL
+ * CH1 -- Touch screen XM/UR
+ * CH2 -- Touch screen YP/LL
+ * CH3 -- Touch screen YM/Sense
+ * CH4 -- Touch screen LR(5-wire only)
+ *
+ * The bitfields below represents the reserved channel in the
+ * touchscreen mode.
+ */
+#define CHAN_MASK_TOUCHSCREEN_4WIRE (0xf << 0)
+#define CHAN_MASK_TOUCHSCREEN_5WIRE (0x1f << 0)
+ enum atmel_adc_ts_type touchscreen_type;
+ struct input_dev *ts_input;
+
+ u8 ts_filter_average;
+ u16 ts_pen_detect_debounce;
+ u8 ts_pen_detect_sensitivity;
+ u16 ts_sample_period_time;
+ u16 ts_sample_period_val;
};
static irqreturn_t at91_adc_trigger_handler(int irq, void *p)
@@ -104,14 +140,10 @@ static irqreturn_t at91_adc_trigger_handler(int irq, void *p)
return IRQ_HANDLED;
}
-static irqreturn_t at91_adc_eoc_trigger(int irq, void *private)
+/* Handler for classic adc channel eoc trigger */
+void handle_adc_eoc_trigger(int irq, struct iio_dev *idev)
{
- struct iio_dev *idev = private;
struct at91_adc_state *st = iio_priv(idev);
- u32 status = at91_adc_readl(st, st->registers->status_register);
-
- if (!(status & st->registers->drdy_mask))
- return IRQ_HANDLED;
if (iio_buffer_enabled(idev)) {
disable_irq_nosync(irq);
@@ -121,6 +153,115 @@ static irqreturn_t at91_adc_eoc_trigger(int irq, void *private)
st->done = true;
wake_up_interruptible(&st->wq_data_avail);
}
+}
+
+static int at91_ts_sample(struct at91_adc_state *st)
+{
+ unsigned int xscale, yscale, reg, z1, z2;
+ unsigned int x, y, pres, xpos, ypos;
+ unsigned int rxp = 1;
+ unsigned int factor = 1000;
+ struct iio_dev *idev = iio_priv_to_dev(st);
+
+ unsigned int xyz_mask_bits = st->caps.has_12bits_xy ? 12 : 10;
+ unsigned int xyz_mask = (1 << xyz_mask_bits) - 1;
+
+ /* calculate position */
+ /* x position = (x / xscale) * max, max = 2^MAX_POS_BITS - 1 */
+ reg = at91_adc_readl(st, AT91_ADC_TSXPOSR);
+ xpos = reg & xyz_mask;
+ x = (xpos << MAX_POS_BITS) - xpos;
+ xscale = (reg >> 16) & xyz_mask;
+ if (xscale != 0)
+ x /= xscale;
+ else
+ dev_err(&idev->dev, "xscale == 0!!!\n");
+
+ /* y position = (y / yscale) * max, max = 2^MAX_POS_BITS - 1 */
+ reg = at91_adc_readl(st, AT91_ADC_TSYPOSR);
+ ypos = reg & xyz_mask;
+ y = (ypos << MAX_POS_BITS) - ypos;
+ yscale = (reg >> 16) & xyz_mask;
+ if (yscale != 0)
+ y /= yscale;
+ else
+ dev_err(&idev->dev, "yscale == 0!!!\n");
+
+ /* calculate the pressure */
+ reg = at91_adc_readl(st, AT91_ADC_TSPRESSR);
+ z1 = reg & xyz_mask;
+ z2 = (reg >> 16) & xyz_mask;
+
+ if (z1 != 0)
+ pres = rxp * (x * factor / 1024) * (z2 * factor / z1 - factor)
+ / factor;
+ else
+ pres = ZTHRESHOLD; /* no pen contacted */
+
+ dev_dbg(&idev->dev, "xpos = %d, xscale = %d, ypos = %d, yscale = %d, z1 = %d, z2 = %d, press = %d\n",
+ xpos, xscale, ypos, yscale, z1, z2, pres);
+
+ if (pres < ZTHRESHOLD) {
+ dev_dbg(&idev->dev, "x = %d, y = %d, pressure = %d\n",
+ x, y, pres / factor);
+ input_report_abs(st->ts_input, ABS_X, x);
+ input_report_abs(st->ts_input, ABS_Y, y);
+ input_report_abs(st->ts_input, ABS_PRESSURE, pres);
+ input_report_key(st->ts_input, BTN_TOUCH, 1);
+ input_sync(st->ts_input);
+ } else {
+ dev_dbg(&idev->dev,
+ "pressure too low: not reporting\n");
+ }
+
+ return 0;
+}
+
+
+static irqreturn_t at91_adc_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);
+ const uint32_t ts_data_irq_mask =
+ AT91_ADC_IER_XRDY |
+ AT91_ADC_IER_YRDY |
+ AT91_ADC_IER_PRDY;
+
+ if (status & st->registers->drdy_mask)
+ handle_adc_eoc_trigger(irq, idev);
+
+ if (status & AT91_ADC_IER_PEN) {
+ at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_PEN);
+ at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_NOPEN |
+ ts_data_irq_mask);
+ /* 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 & AT91_ADC_IER_NOPEN) {
+ at91_adc_writel(st, st->registers->trigger_register, 0);
+ at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_NOPEN |
+ ts_data_irq_mask);
+ at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_PEN);
+
+ input_report_key(st->ts_input, BTN_TOUCH, 0);
+ input_sync(st->ts_input);
+ } else if ((status & ts_data_irq_mask) == ts_data_irq_mask) {
+ /* Now all touchscreen data is ready */
+
+ if (status & AT91_ADC_ISR_PENS) {
+ /* validate data by pen contact */
+ at91_ts_sample(st);
+ } else {
+ /* triggered by event that is no pen contact, just read
+ * them to clean the interrupt and discard all.
+ */
+ at91_adc_readl(st, AT91_ADC_TSXPOSR);
+ at91_adc_readl(st, AT91_ADC_TSYPOSR);
+ at91_adc_readl(st, AT91_ADC_TSPRESSR);
+ }
+ }
return IRQ_HANDLED;
}
@@ -130,6 +271,16 @@ static int at91_adc_channel_init(struct iio_dev *idev)
struct at91_adc_state *st = iio_priv(idev);
struct iio_chan_spec *chan_array, *timestamp;
int bit, idx = 0;
+ unsigned long rsvd_mask = 0;
+
+ /* If touchscreen is enable, then reserve the adc channels */
+ if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_4WIRE)
+ rsvd_mask = CHAN_MASK_TOUCHSCREEN_4WIRE;
+ else if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_5WIRE)
+ rsvd_mask = CHAN_MASK_TOUCHSCREEN_5WIRE;
+
+ /* set up the channel mask to reserve touchscreen channels */
+ st->channels_mask &= ~rsvd_mask;
idev->num_channels = bitmap_weight(&st->channels_mask,
st->num_channels) + 1;
@@ -561,6 +712,57 @@ static int at91_adc_probe_dt(struct at91_adc_state *st,
i++;
}
+ /* Check if touchscreen is enabled in DT. */
+ ret = of_property_read_u32(node, "atmel,adc-touchscreen-wires", &prop);
+ if (ret)
+ dev_info(&idev->dev, "Touchscreen not enabled.\n");
+ else if (prop == 4)
+ st->touchscreen_type = ATMEL_ADC_TOUCHSCREEN_4WIRE;
+ else if (prop == 5)
+ st->touchscreen_type = ATMEL_ADC_TOUCHSCREEN_5WIRE;
+ else
+ dev_warn(&idev->dev, "Unsupported number of touchscreen wires (%d)\n",
+ prop);
+
+ if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_NONE)
+ return 0;
+
+ /* Touch screen is enabled, so check touch screen dt parameters */
+ if (of_property_read_u32(node, "atmel,adc-ts-filter-average", &prop)) {
+ dev_err(&idev->dev, "Missing atmel,adc-ts-filtering-average property in the DT.\n");
+ ret = -EINVAL;
+ goto error_ret;
+ }
+ st->ts_filter_average = prop;
+ if (st->ts_filter_average > 3) {
+ dev_err(&idev->dev, "Invalid atmel,adc-ts-filtering-average property in the DT.\n");
+ ret = -EINVAL;
+ goto error_ret;
+ }
+
+ prop = 0;
+ of_property_read_u32(node, "atmel,adc-ts-pendet-debounce", &prop);
+ st->ts_pen_detect_debounce = prop;
+
+ /* default sample period is 2ms. The real touch sample period should be
+ * this period * TSFREQ.
+ */
+ prop = 2000;
+ of_property_read_u32(node, "atmel,adc-ts-sample-period-time", &prop);
+ st->ts_sample_period_time = prop;
+
+ if (of_property_read_u32(node, "atmel,adc-ts-pendet-sensitivity", &prop)) {
+ dev_err(&idev->dev, "Missing atmel,adc-ts-pendet-sensitivity property in the DT.\n");
+ ret = -EINVAL;
+ goto error_ret;
+ }
+ st->ts_pen_detect_sensitivity = prop;
+ if (st->ts_pen_detect_sensitivity > 3) {
+ dev_err(&idev->dev, "Invalid atmel,adc-ts-pendet-sensitivity property in the DT.\n");
+ ret = -EINVAL;
+ goto error_ret;
+ }
+
return 0;
error_ret:
@@ -592,6 +794,114 @@ static const struct iio_info at91_adc_info = {
.read_raw = &at91_adc_read_raw,
};
+/* Touchscreen related functions */
+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);
+ return 0;
+}
+
+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);
+}
+
+static int at91_ts_hw_init(struct at91_adc_state *st, u32 adc_clk_khz)
+{
+ u32 reg = 0, pendbc;
+ 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(st->ts_pen_detect_debounce * adc_clk_khz / 1000, 1);
+
+ while (pendbc >> ++i)
+ ; /* Empty! Find the shift offset */
+ if (abs(pendbc - (1 << i)) < abs(pendbc - (1 << (i - 1))))
+ pendbc = i;
+ else
+ pendbc = i - 1;
+
+ if (st->caps.has_tsmr) {
+ reg |= AT91_ADC_TSMR_TSAV_(st->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 */
+ }
+
+ /* 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
+ * option only available on ES2 and higher
+ */
+ at91_adc_writel(st, AT91_ADC_ACR, st->ts_pen_detect_sensitivity
+ & AT91_ADC_ACR_PENDETSENS);
+
+ /* Sample Peroid Time = (TRGPER + 1) / ADCClock */
+ st->ts_sample_period_val = round_up((st->ts_sample_period_time *
+ adc_clk_khz / 1000) - 1, 1);
+
+ return 0;
+}
+
+static int at91_ts_register(struct at91_adc_state *st)
+{
+ struct input_dev *input;
+ struct iio_dev *idev = iio_priv_to_dev(st);
+ int ret;
+
+ input = input_allocate_device();
+ if (!input) {
+ dev_err(&idev->dev, "Failed to allocate TS device!\n");
+ return -ENOMEM;
+ }
+
+ input->name = DRIVER_NAME;
+ input->id.bustype = BUS_HOST;
+ input->dev.parent = idev->dev.parent;
+ input->open = atmel_ts_open;
+ input->close = atmel_ts_close;
+
+ __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);
+
+ st->ts_input = input;
+ input_set_drvdata(input, st);
+
+ ret = input_register_device(input);
+ if (ret)
+ input_free_device(st->ts_input);
+
+ return ret;
+}
+
+static void at91_ts_unregister(struct at91_adc_state *st)
+{
+ input_unregister_device(st->ts_input);
+ input_free_device(st->ts_input);
+}
+
/*
* Since atmel adc support different ip for touchscreen mode. Through the
* IP check, we will know the touchscreen capbilities.
@@ -610,6 +920,7 @@ static void atmel_adc_get_cap(struct at91_adc_state *st)
/* keep only major version number */
switch (version & 0xf00) {
case 0x500: /* SAMA5D3 */
+ st->caps.has_12bits_xy = 1;
case 0x400: /* AT91SAM9X5/9N12 */
st->caps.has_tsmr = 1;
st->caps.mr_startup_mask = AT91_ADC_STARTUP;
@@ -683,7 +994,7 @@ 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_eoc_trigger,
+ at91_adc_interrupt,
0,
pdev->dev.driver->name,
idev);
@@ -731,6 +1042,10 @@ static int at91_adc_probe(struct platform_device *pdev)
adc_clk = st->adc_clk_rate ?
st->adc_clk_rate : clk_get_rate(st->adc_clk);
adc_clk_khz = adc_clk / 1000;
+
+ dev_dbg(&pdev->dev, "Master clock is set as: %d Hz, adc_clk should set as: %d Hz\n",
+ mstrclk, adc_clk);
+
prsc = (mstrclk / (2 * adc_clk)) - 1;
if (!st->startup_time) {
@@ -799,30 +1114,52 @@ static int at91_adc_probe(struct platform_device *pdev)
init_waitqueue_head(&st->wq_data_avail);
mutex_init(&st->lock);
- ret = at91_adc_buffer_init(idev);
- if (ret < 0) {
- dev_err(&pdev->dev, "Couldn't initialize the buffer.\n");
- goto error_disable_adc_clk;
- }
+ /*
+ * Since touch screen will set trigger register as period trigger. So
+ * when touch screen is enabled, then we have to disable hardware
+ * trigger for classic adc.
+ */
+ if (!st->touchscreen_type) {
+ ret = at91_adc_buffer_init(idev);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Couldn't initialize the buffer.\n");
+ goto error_disable_adc_clk;
+ }
- ret = at91_adc_trigger_init(idev);
- if (ret < 0) {
- dev_err(&pdev->dev, "Couldn't setup the triggers.\n");
- goto error_unregister_buffer;
+ ret = at91_adc_trigger_init(idev);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Couldn't setup the triggers.\n");
+ at91_adc_buffer_remove(idev);
+ goto error_disable_adc_clk;
+ }
+ } else {
+ if (!st->caps.has_tsmr) {
+ dev_err(&pdev->dev, "We don't support non-TSMR adc\n");
+ goto error_disable_adc_clk;
+ }
+
+ ret = at91_ts_register(st);
+ if (ret)
+ goto error_disable_adc_clk;
+
+ at91_ts_hw_init(st, adc_clk_khz);
}
ret = iio_device_register(idev);
if (ret < 0) {
dev_err(&pdev->dev, "Couldn't register the device.\n");
- goto error_remove_triggers;
+ goto error_iio_device_register;
}
return 0;
-error_remove_triggers:
- at91_adc_trigger_remove(idev);
-error_unregister_buffer:
- at91_adc_buffer_remove(idev);
+error_iio_device_register:
+ if (!st->touchscreen_type) {
+ at91_adc_trigger_remove(idev);
+ at91_adc_buffer_remove(idev);
+ } else {
+ at91_ts_unregister(st);
+ }
error_disable_adc_clk:
clk_disable_unprepare(st->adc_clk);
error_disable_clk:
@@ -841,8 +1178,12 @@ static int at91_adc_remove(struct platform_device *pdev)
struct at91_adc_state *st = iio_priv(idev);
iio_device_unregister(idev);
- at91_adc_trigger_remove(idev);
- at91_adc_buffer_remove(idev);
+ if (!st->touchscreen_type) {
+ at91_adc_trigger_remove(idev);
+ at91_adc_buffer_remove(idev);
+ } else {
+ at91_ts_unregister(st);
+ }
clk_disable_unprepare(st->adc_clk);
clk_disable_unprepare(st->clk);
free_irq(st->irq, idev);
@@ -861,7 +1202,7 @@ static struct platform_driver at91_adc_driver = {
.probe = at91_adc_probe,
.remove = at91_adc_remove,
.driver = {
- .name = "at91_adc",
+ .name = DRIVER_NAME,
.of_match_table = of_match_ptr(at91_adc_dt_ids),
},
};
--
1.7.10
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
