[PATCH 5/5] IIO: AT91: Add support for hardware triggers for the ADC
Maxime Ripard
maxime.ripard at free-electrons.com
Thu Apr 5 12:01:24 EDT 2012
This patch adds support for the hardware triggers for both the
AT91SAM9G20-EK and AT91SAM9M10G45-EK evaluation board from Atmel.
Signed-off-by: Maxime Ripard <maxime.ripard at free-electrons.com>
Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj at jcrosoft.com>
Cc: Patrice Vilchez <patrice.vilchez at atmel.com>
Cc: Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
Cc: Nicolas Ferre <nicolas.ferre at atmel.com>
---
arch/arm/mach-at91/at91sam9260_devices.c | 3 +
arch/arm/mach-at91/at91sam9g45_devices.c | 3 +
arch/arm/mach-at91/board-sam9g20ek.c | 1 +
arch/arm/mach-at91/board-sam9m10g45ek.c | 1 +
drivers/staging/iio/adc/Kconfig | 3 +
drivers/staging/iio/adc/at91_adc.c | 390 +++++++++++++++++++++++++++++-
include/linux/platform_data/at91_adc.h | 2 +
7 files changed, 396 insertions(+), 7 deletions(-)
diff --git a/arch/arm/mach-at91/at91sam9260_devices.c b/arch/arm/mach-at91/at91sam9260_devices.c
index 08464fe..66df43a 100644
--- a/arch/arm/mach-at91/at91sam9260_devices.c
+++ b/arch/arm/mach-at91/at91sam9260_devices.c
@@ -1412,6 +1412,9 @@ void __init at91_add_device_adc(struct at91_adc_data *data)
if (test_bit(3, &data->channels_used))
at91_set_A_periph(AT91_PIN_PC3, 0);
+ if (data->use_external)
+ at91_set_A_periph(AT91_PIN_PA22, 0);
+
adc_data = *data;
platform_device_register(&at91_adc_device);
}
diff --git a/arch/arm/mach-at91/at91sam9g45_devices.c b/arch/arm/mach-at91/at91sam9g45_devices.c
index 7827139..13ac3932 100644
--- a/arch/arm/mach-at91/at91sam9g45_devices.c
+++ b/arch/arm/mach-at91/at91sam9g45_devices.c
@@ -1255,6 +1255,9 @@ void __init at91_add_device_adc(struct at91_adc_data *data)
if (test_bit(7, &data->channels_used))
at91_set_gpio_input(AT91_PIN_PD27, 0);
+ if (data->use_external)
+ at91_set_A_periph(AT91_PIN_PD28, 0);
+
adc_data = *data;
platform_device_register(&at91_adc_device);
}
diff --git a/arch/arm/mach-at91/board-sam9g20ek.c b/arch/arm/mach-at91/board-sam9g20ek.c
index 2ce4e26..3bb6e4d 100644
--- a/arch/arm/mach-at91/board-sam9g20ek.c
+++ b/arch/arm/mach-at91/board-sam9g20ek.c
@@ -326,6 +326,7 @@ static void __init ek_add_device_buttons(void) {}
static struct at91_adc_data ek_adc_data = {
.channels_used = BIT(0) | BIT(1) | BIT(2) | BIT(3),
+ .use_external = true,
.vref = 3300,
};
diff --git a/arch/arm/mach-at91/board-sam9m10g45ek.c b/arch/arm/mach-at91/board-sam9m10g45ek.c
index dca46c8..9a89afc 100644
--- a/arch/arm/mach-at91/board-sam9m10g45ek.c
+++ b/arch/arm/mach-at91/board-sam9m10g45ek.c
@@ -321,6 +321,7 @@ static struct at91_tsadcc_data ek_tsadcc_data = {
*/
static struct at91_adc_data ek_adc_data = {
.channels_used = BIT(0) | BIT(1) | BIT(2) | BIT(3) | BIT(4) | BIT(5) | BIT(6) | BIT(7),
+ .use_external = true,
.vref = 3300,
};
diff --git a/drivers/staging/iio/adc/Kconfig b/drivers/staging/iio/adc/Kconfig
index 1494838..9ee7ed9 100644
--- a/drivers/staging/iio/adc/Kconfig
+++ b/drivers/staging/iio/adc/Kconfig
@@ -172,6 +172,9 @@ config AD7280
config AT91_ADC
tristate "Atmel AT91 ADC"
depends on SYSFS && ARCH_AT91
+ select IIO_BUFFER
+ select IIO_SW_RING
+ select IIO_TRIGGER
help
Say yes here to build support for Atmel AT91 ADC.
diff --git a/drivers/staging/iio/adc/at91_adc.c b/drivers/staging/iio/adc/at91_adc.c
index 04bac43..57e2161 100644
--- a/drivers/staging/iio/adc/at91_adc.c
+++ b/drivers/staging/iio/adc/at91_adc.c
@@ -23,9 +23,33 @@
#include "../iio.h"
#include <linux/platform_data/at91_adc.h>
+#include "../buffer.h"
+#include "../ring_sw.h"
+#include "../trigger.h"
+#include "../trigger_consumer.h"
+
#include <mach/at91_adc.h>
#include <mach/cpu.h>
+#define AT91_TSADCC_TRGR (0x08)
+#define AT91_TSADCC_TRGMOD_EXT_RISING (1 << 0)
+#define AT91_TSADCC_TRGMOD_EXT_FALLING (1 << 1)
+#define AT91_TSADCC_TRGMOD_EXT_ANY (AT91_TSADCC_TRGMOD_EXT_RISING | AT91_TSADCC_TRGMOD_EXT_FALLING)
+#define AT91_TSADCC_TRGMOD_CONTINUOUS (3 << 1)
+
+/**
+ * struct at91_adc_trigger - description of triggers
+ * @name: name of the trigger advertised to the user
+ * @value: value to set in the ADC's mode register to enable
+ the trigger
+ * @is_external: is the trigger relies on an external pin ?
+ */
+struct at91_adc_trigger {
+ char *name;
+ u8 value;
+ bool is_external;
+};
+
/**
* struct at91_adc_desc - description of the ADC on the board
* @clock: ADC clock as specified by the datasheet, in Hz.
@@ -35,32 +59,93 @@
board, see the channels_used bitmask in the platform
data)
* @startup_time: startup time of the ADC in microseconds
+ * @triggers: array of the triggers available on the board
+ * @trigger_register: index of the register managing the hardware triggers
*/
struct at91_adc_desc {
u32 clock;
char *clock_name;
u8 num_channels;
u8 startup_time;
+ struct at91_adc_trigger *triggers;
+ u8 trigger_register;
};
struct at91_adc_state {
+ u16 *buffer;
unsigned long channels_mask;
struct clk *clk;
bool done;
struct at91_adc_desc *desc;
int irq;
+ bool irq_enabled;
u16 last_value;
struct mutex lock;
void __iomem *reg_base;
+ struct iio_trigger **trig;
u32 vref_mv;
wait_queue_head_t wq_data_avail;
};
+static struct at91_adc_trigger at91_adc_trigger_sam9g45[] = {
+ [0] = {
+ .name = "external-rising",
+ .value = AT91_TSADCC_TRGMOD_EXT_RISING,
+ .is_external = true,
+ },
+ [1] = {
+ .name = "external-falling",
+ .value = AT91_TSADCC_TRGMOD_EXT_FALLING,
+ .is_external = true,
+ },
+ [2] = {
+ .name = "external-any",
+ .value = AT91_TSADCC_TRGMOD_EXT_ANY,
+ .is_external = true,
+ },
+ [3] = {
+ .name = "continuous",
+ .value = AT91_TSADCC_TRGMOD_CONTINUOUS,
+ .is_external = false,
+ },
+ [4] = {
+ .name = NULL,
+ },
+};
+
static struct at91_adc_desc at91_adc_desc_sam9g45 = {
.clock = 13200000,
.clock_name = "tsc_clk",
.num_channels = 8,
.startup_time = 40,
+ .triggers = at91_adc_trigger_sam9g45,
+ .trigger_register = AT91_TSADCC_TRGR,
+};
+
+static struct at91_adc_trigger at91_adc_trigger_sam9g20[] = {
+ [0] = {
+ .name = "timer-counter-0",
+ .value = AT91_ADC_TRGSEL_TC0 | AT91_ADC_TRGEN,
+ .is_external = false,
+ },
+ [1] = {
+ .name = "timer-counter-1",
+ .value = AT91_ADC_TRGSEL_TC1 | AT91_ADC_TRGEN,
+ .is_external = false,
+ },
+ [2] = {
+ .name = "timer-counter-2",
+ .value = AT91_ADC_TRGSEL_TC2 | AT91_ADC_TRGEN,
+ .is_external = false,
+ },
+ [3] = {
+ .name = "external",
+ .value = AT91_ADC_TRGSEL_EXTERNAL | AT91_ADC_TRGEN,
+ .is_external = true,
+ },
+ [4] = {
+ .name = NULL,
+ },
};
static struct at91_adc_desc at91_adc_desc_sam9g20 = {
@@ -68,6 +153,8 @@ static struct at91_adc_desc at91_adc_desc_sam9g20 = {
.clock_name = "adc_clk",
.num_channels = 4,
.startup_time = 10,
+ .triggers = at91_adc_trigger_sam9g20,
+ .trigger_register = AT91_ADC_MR,
};
static int at91_adc_select_soc(struct at91_adc_state *st)
@@ -98,6 +185,48 @@ static inline void at91_adc_reg_write(struct at91_adc_state *st,
writel_relaxed(val, st->reg_base + reg);
}
+static irqreturn_t at91_adc_trigger_handler(int irq, void *p)
+{
+ struct iio_poll_func *pf = p;
+ struct iio_dev *idev = pf->indio_dev;
+ struct at91_adc_state *st = iio_priv(idev);
+ struct iio_buffer *buffer = idev->buffer;
+ int len = 0;
+
+ if (!bitmap_empty(idev->active_scan_mask, idev->masklength)) {
+ int i, j;
+ for (i = 0, j = 0;
+ i < bitmap_weight(idev->active_scan_mask,
+ idev->masklength);
+ i++) {
+ j = find_next_bit(buffer->scan_mask,
+ idev->masklength,
+ j);
+ st->buffer[i] = at91_adc_reg_read(st, AT91_ADC_CHR(j));
+ j++;
+ len += 2;
+ }
+ }
+
+ if (buffer->scan_timestamp) {
+ s64 *timestamp = (s64 *)((u8 *)st->buffer + ALIGN(len,
+ sizeof(s64)));
+ *timestamp = pf->timestamp;
+ }
+
+ buffer->access->store_to(buffer, (u8 *)st->buffer, pf->timestamp);
+
+ iio_trigger_notify_done(idev->trig);
+ st->irq_enabled = true;
+
+ /* Needed to ACK the DRDY interruption */
+ at91_adc_reg_read(st, AT91_ADC_LCDR);
+
+ enable_irq(st->irq);
+
+ return IRQ_HANDLED;
+}
+
static irqreturn_t at91_adc_eoc_trigger(int irq, void *private)
{
struct iio_dev *idev = private;
@@ -107,13 +236,16 @@ static irqreturn_t at91_adc_eoc_trigger(int irq, void *private)
if (!(status & AT91_ADC_DRDY))
return IRQ_HANDLED;
- if (status & st->channels_mask) {
- st->done = true;
+ if (iio_buffer_enabled(idev)) {
+ disable_irq_nosync(irq);
+ st->irq_enabled = false;
+ iio_trigger_poll(idev->trig, iio_get_time_ns());
+ } else {
st->last_value = at91_adc_reg_read(st, AT91_ADC_LCDR);
+ st->done = true;
+ wake_up_interruptible(&st->wq_data_avail);
}
- wake_up_interruptible(&st->wq_data_avail);
-
return IRQ_HANDLED;
}
@@ -125,8 +257,9 @@ static int at91_adc_channel_init(struct iio_dev *idev,
int bit, idx = 0;
idev->num_channels = bitmap_weight(&pdata->channels_used,
- st->desc->num_channels);
- chan_array = kcalloc(idev->num_channels, sizeof(struct iio_chan_spec),
+ st->desc->num_channels) + 1;
+ chan_array = kcalloc(idev->num_channels + 1,
+ sizeof(struct iio_chan_spec),
GFP_KERNEL);
if (chan_array == NULL)
@@ -137,6 +270,7 @@ static int at91_adc_channel_init(struct iio_dev *idev,
chan->type = IIO_VOLTAGE;
chan->indexed = 1;
chan->channel = bit;
+ chan->scan_index = idx;
chan->scan_type.sign = 'u';
chan->scan_type.realbits = 10;
chan->scan_type.storagebits = 16;
@@ -144,6 +278,13 @@ static int at91_adc_channel_init(struct iio_dev *idev,
idx++;
}
+ (chan_array + idx)->type = IIO_TIMESTAMP;
+ (chan_array + idx)->channel = -1;
+ (chan_array + idx)->scan_index = idx;
+ (chan_array + idx)->scan_type.sign = 's';
+ (chan_array + idx)->scan_type.realbits = 64;
+ (chan_array + idx)->scan_type.storagebits = 64;
+
idev->channels = chan_array;
return idev->num_channels;
}
@@ -153,6 +294,223 @@ static void at91_adc_channel_remove(struct iio_dev *idev)
kfree(idev->channels);
}
+static u8 at91_adc_get_trigger_value_by_name(struct iio_dev *idev,
+ struct at91_adc_trigger *triggers,
+ const char *trigger_name)
+{
+ u8 value = 0;
+ int i;
+
+ for (i = 0; (triggers + i) != NULL; i++) {
+ char *name = kasprintf(GFP_KERNEL,
+ "%s-dev%d-%s",
+ idev->name,
+ idev->id,
+ triggers[i].name);
+ if (name == NULL)
+ return -ENOMEM;
+
+ if (strcmp(trigger_name, name) == 0) {
+ value = triggers[i].value;
+ kfree(name);
+ break;
+ }
+
+ kfree(name);
+ }
+
+ return value;
+}
+
+static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state)
+{
+ struct iio_dev *idev = trig->private_data;
+ struct at91_adc_state *st = iio_priv(idev);
+ struct iio_buffer *buffer = idev->buffer;
+ u32 status = at91_adc_reg_read(st, st->desc->trigger_register);
+ u8 value;
+ u8 bit;
+
+ value = at91_adc_get_trigger_value_by_name(idev,
+ st->desc->triggers,
+ idev->trig->name);
+ if (value == 0)
+ return -EINVAL;
+
+ if (state) {
+ size_t datasize = buffer->access->get_bytes_per_datum(buffer);
+
+ st->buffer = kmalloc(datasize, GFP_KERNEL);
+ if (st->buffer == NULL)
+ return -ENOMEM;
+
+ at91_adc_reg_write(st,
+ st->desc->trigger_register,
+ status | value);
+
+ for_each_set_bit(bit, buffer->scan_mask,
+ st->desc->num_channels) {
+ struct iio_chan_spec const *chan = idev->channels + bit;
+ at91_adc_reg_write(st, AT91_ADC_CHER,
+ AT91_ADC_CH(chan->channel));
+ }
+
+ at91_adc_reg_write(st, AT91_ADC_IER, AT91_ADC_DRDY);
+
+ } else {
+ at91_adc_reg_write(st, AT91_ADC_IDR, AT91_ADC_DRDY);
+
+ at91_adc_reg_write(st, st->desc->trigger_register,
+ status & ~value);
+
+ for_each_set_bit(bit, buffer->scan_mask,
+ st->desc->num_channels) {
+ struct iio_chan_spec const *chan = idev->channels + bit;
+ at91_adc_reg_write(st, AT91_ADC_CHDR,
+ AT91_ADC_CH(chan->channel));
+ }
+ kfree(st->buffer);
+ }
+
+ return 0;
+}
+
+static const struct iio_trigger_ops at91_adc_trigger_ops = {
+ .owner = THIS_MODULE,
+ .set_trigger_state = &at91_adc_configure_trigger,
+};
+
+static struct iio_trigger *at91_adc_allocate_trigger(struct iio_dev *idev,
+ struct at91_adc_trigger *trigger)
+{
+ struct iio_trigger *trig = iio_allocate_trigger("%s-dev%d-%s",
+ idev->name,
+ idev->id,
+ trigger->name);
+ int ret;
+
+ if (trig == NULL)
+ return NULL;
+
+ trig->dev.parent = idev->dev.parent;
+ trig->private_data = idev;
+ trig->ops = &at91_adc_trigger_ops;
+
+ ret = iio_trigger_register(trig);
+ if (ret < 0)
+ return NULL;
+
+ return trig;
+}
+
+static int at91_adc_trigger_init(struct iio_dev *idev,
+ struct at91_adc_data *pdata)
+{
+ struct at91_adc_state *st = iio_priv(idev);
+ int i, ret;
+
+ st->trig = kcalloc(sizeof(st->desc->triggers),
+ sizeof(st->trig),
+ GFP_KERNEL);
+
+ if (st->trig == NULL) {
+ ret = -ENOMEM;
+ goto error_ret;
+ }
+
+ for (i = 0; st->desc->triggers[i].name != NULL; i++) {
+ if (st->desc->triggers[i].is_external && !(pdata->use_external))
+ continue;
+
+ st->trig[i] = at91_adc_allocate_trigger(idev,
+ st->desc->triggers + i);
+ if (st->trig[i] == NULL) {
+ dev_err(&idev->dev,
+ "Could not allocate trigger %d\n", i);
+ ret = -ENOMEM;
+ goto error_trigger;
+ }
+ }
+
+ return 0;
+
+error_trigger:
+ for (i--; i >= 0; i--) {
+ iio_trigger_unregister(st->trig[i]);
+ iio_free_trigger(st->trig[i]);
+ }
+ kfree(st->trig);
+error_ret:
+ return ret;
+}
+
+static void at91_adc_trigger_remove(struct iio_dev *idev)
+{
+ struct at91_adc_state *st = iio_priv(idev);
+ int i;
+
+ for (i = 0; st->desc->triggers[i].name != NULL; i++) {
+ iio_trigger_unregister(st->trig[i]);
+ iio_free_trigger(st->trig[i]);
+ }
+
+ kfree(st->trig);
+}
+
+static const struct iio_buffer_setup_ops at91_adc_buffer_ops = {
+ .preenable = &iio_sw_buffer_preenable,
+ .postenable = &iio_triggered_buffer_postenable,
+ .predisable = &iio_triggered_buffer_predisable,
+};
+
+static int at91_adc_buffer_init(struct iio_dev *idev)
+{
+ int ret;
+
+ idev->buffer = iio_sw_rb_allocate(idev);
+ if (!idev->buffer) {
+ ret = -ENOMEM;
+ goto error_ret;
+ }
+
+ idev->pollfunc = iio_alloc_pollfunc(&iio_pollfunc_store_time,
+ &at91_adc_trigger_handler,
+ IRQF_ONESHOT,
+ idev,
+ "%s-consumer%d",
+ idev->name,
+ idev->id);
+ if (idev->pollfunc == NULL) {
+ ret = -ENOMEM;
+ goto error_pollfunc;
+ }
+
+ idev->setup_ops = &at91_adc_buffer_ops;
+ idev->modes |= INDIO_BUFFER_TRIGGERED;
+
+ ret = iio_buffer_register(idev,
+ idev->channels,
+ idev->num_channels);
+ if (ret)
+ goto error_register;
+
+ return 0;
+
+error_register:
+ iio_dealloc_pollfunc(idev->pollfunc);
+error_pollfunc:
+ iio_sw_rb_free(idev->buffer);
+error_ret:
+ return ret;
+}
+
+static void at91_adc_buffer_remove(struct iio_dev *idev)
+{
+ iio_buffer_unregister(idev);
+ iio_dealloc_pollfunc(idev->pollfunc);
+ iio_sw_rb_free(idev->buffer);
+}
+
static int at91_adc_read_raw(struct iio_dev *idev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
@@ -336,14 +694,30 @@ static int __devinit at91_adc_probe(struct platform_device *pdev)
st->vref_mv = pdata->vref;
st->channels_mask = pdata->channels_used;
+ ret = at91_adc_buffer_init(idev);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Couldn't initialize the buffer.\n");
+ goto error_free_channels;
+ }
+
+ ret = at91_adc_trigger_init(idev, pdata);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Couldn't setup the triggers.\n");
+ goto error_unregister_buffer;
+ }
+
ret = iio_device_register(idev);
if (ret < 0) {
dev_err(&pdev->dev, "Couldn't register the device.\n");
- goto error_free_channels;
+ goto error_remove_triggers;
}
return 0;
+error_remove_triggers:
+ at91_adc_trigger_remove(idev);
+error_unregister_buffer:
+ at91_adc_buffer_remove(idev);
error_free_channels:
at91_adc_channel_remove(idev);
error_free_clk:
@@ -368,6 +742,8 @@ static int __devexit 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);
at91_adc_channel_remove(idev);
clk_disable(st->clk);
clk_put(st->clk);
diff --git a/include/linux/platform_data/at91_adc.h b/include/linux/platform_data/at91_adc.h
index 1f71510..5e063b3 100644
--- a/include/linux/platform_data/at91_adc.h
+++ b/include/linux/platform_data/at91_adc.h
@@ -11,10 +11,12 @@
/**
* struct at91_adc_data - platform data for ADC driver
* @channels_used: channels in use on the board as a bitmask
+ * @use_external: does the board has external triggers availables
* @vref: Reference voltage for the ADC in millivolts
*/
struct at91_adc_data {
unsigned long channels_used;
+ bool use_external;
u16 vref;
};
--
1.7.5.4
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