summaryrefslogtreecommitdiffstats
path: root/drivers/iio
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/iio')
-rw-r--r--drivers/iio/adc/at91_adc.c388
1 files changed, 364 insertions, 24 deletions
diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c
index 690a560e0da..17df74908db 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>
@@ -39,7 +40,23 @@
#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 TOUCH_SAMPLE_PERIOD_US 2000 /* 2ms */
+#define TOUCH_PEN_DETECT_DEBOUNCE_US 200
+
struct at91_adc_caps {
+ bool has_ts; /* Support touch screen */
+ bool has_tsmr; /* only at91sam9x5, sama5d3 have TSMR reg */
+ /*
+ * Numbers of sampling data will be averaged. Can be 0~3.
+ * Hardware can average (2 ^ ts_filter_average) sample data.
+ */
+ u8 ts_filter_average;
+ /* Pen Detection input pull-up resistor, can be 0~3 */
+ u8 ts_pen_detect_sensitivity;
+
/* startup time calculate function */
u32 (*calc_startup_ticks)(u8 startup_time, u32 adc_clk_khz);
@@ -47,6 +64,12 @@ 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;
@@ -71,6 +94,26 @@ 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;
+
+ u16 ts_sample_period_val;
+ u32 ts_pressure_threshold;
};
static irqreturn_t at91_adc_trigger_handler(int irq, void *p)
@@ -99,14 +142,10 @@ 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);
@@ -116,6 +155,115 @@ 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->res;
+ 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) {
+ dev_err(&idev->dev, "Error: xscale == 0!\n");
+ return -1;
+ }
+ x /= xscale;
+
+ /* 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) {
+ dev_err(&idev->dev, "Error: yscale == 0!\n");
+ return -1;
+ }
+ y /= yscale;
+
+ /* 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 = st->ts_pressure_threshold; /* 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 < st->ts_pressure_threshold) {
+ 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;
}
@@ -125,6 +273,16 @@ 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;
@@ -473,6 +631,39 @@ static u32 calc_startup_ticks_9x5(u8 startup_time, u32 adc_clk_khz)
static const struct of_device_id at91_adc_dt_ids[];
+static int at91_adc_probe_dt_ts(struct device_node *node,
+ struct at91_adc_state *st, struct device *dev)
+{
+ int ret;
+ u32 prop;
+
+ ret = of_property_read_u32(node, "atmel,adc-ts-wires", &prop);
+ if (ret) {
+ dev_info(dev, "ADC Touch screen is disabled.\n");
+ return 0;
+ }
+
+ switch (prop) {
+ case 4:
+ case 5:
+ st->touchscreen_type = prop;
+ break;
+ default:
+ dev_err(dev, "Unsupported number of touchscreen wires (%d). Should be 4 or 5.\n", prop);
+ return -EINVAL;
+ }
+
+ prop = 0;
+ of_property_read_u32(node, "atmel,adc-ts-pressure-threshold", &prop);
+ st->ts_pressure_threshold = prop;
+ if (st->ts_pressure_threshold) {
+ return 0;
+ } else {
+ dev_err(dev, "Invalid pressure threshold for the touchscreen\n");
+ return -EINVAL;
+ }
+}
+
static int at91_adc_probe_dt(struct at91_adc_state *st,
struct platform_device *pdev)
{
@@ -554,6 +745,12 @@ static int at91_adc_probe_dt(struct at91_adc_state *st,
i++;
}
+ /* Check if touchscreen is supported. */
+ if (st->caps->has_ts)
+ return at91_adc_probe_dt_ts(node, st, &idev->dev);
+ else
+ dev_info(&idev->dev, "not support touchscreen in the adc compatible string.\n");
+
return 0;
error_ret:
@@ -585,6 +782,114 @@ 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(TOUCH_PEN_DETECT_DEBOUNCE_US * 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->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 */
+ }
+
+ /* 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->caps->ts_pen_detect_sensitivity
+ & AT91_ADC_ACR_PENDETSENS);
+
+ /* Sample Peroid Time = (TRGPER + 1) / ADCClock */
+ st->ts_sample_period_val = round_up((TOUCH_SAMPLE_PERIOD_US *
+ adc_clk_khz / 1000) - 1, 1);
+
+ return 0;
+}
+
+static int at91_ts_register(struct at91_adc_state *st,
+ struct platform_device *pdev)
+{
+ 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 = &pdev->dev;
+ 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);
+}
+
static int at91_adc_probe(struct platform_device *pdev)
{
unsigned int prsc, mstrclk, ticks, adc_clk, adc_clk_khz, shtim;
@@ -636,7 +941,7 @@ 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);
@@ -681,6 +986,10 @@ static int at91_adc_probe(struct platform_device *pdev)
mstrclk = clk_get_rate(st->clk);
adc_clk = 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) {
@@ -717,30 +1026,52 @@ 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, pdev);
+ 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:
@@ -756,8 +1087,12 @@ 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);
@@ -780,6 +1115,7 @@ static struct at91_adc_caps at91sam9260_caps = {
};
static struct at91_adc_caps at91sam9g45_caps = {
+ .has_ts = true,
.calc_startup_ticks = calc_startup_ticks_9260, /* same as 9260 */
.num_channels = 8,
.registers = {
@@ -793,6 +1129,10 @@ static struct at91_adc_caps at91sam9g45_caps = {
};
static struct at91_adc_caps at91sam9x5_caps = {
+ .has_ts = true,
+ .has_tsmr = true,
+ .ts_filter_average = 3,
+ .ts_pen_detect_sensitivity = 2,
.calc_startup_ticks = calc_startup_ticks_9x5,
.num_channels = 12,
.registers = {
@@ -819,7 +1159,7 @@ 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),
},
};
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-22 00:59:54 +0000