staging:iio:trigger:bfintmr Add output support

Some converters require an external signal to start the conversion. This patch
adds support to the bfintmr trigger driver to generate such a signal.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

diff --git a/drivers/staging/iio/trigger/iio-trig-bfin-timer.c b/drivers/staging/iio/trigger/iio-trig-bfin-timer.c
index d9d3dc9..52062d7 100644 (file)
--- a/drivers/staging/iio/trigger/iio-trig-bfin-timer.c
+++ b/drivers/staging/iio/trigger/iio-trig-bfin-timer.c
@@ -14,14 +14,18 @@
 #include <linux/delay.h>
 
 #include <asm/gptimers.h>
+#include <asm/portmux.h>
 
 #include <linux/iio/iio.h>
 #include <linux/iio/trigger.h>
 
+#include "iio-trig-bfin-timer.h"
+
 struct bfin_timer {
        unsigned short id, bit;
        unsigned long irqbit;
        int irq;
+       int pin;
 };
 
 /*
@@ -30,22 +34,22 @@ struct bfin_timer {
  */
 
 static struct bfin_timer iio_bfin_timer_code[MAX_BLACKFIN_GPTIMERS] = {
-       {TIMER0_id,  TIMER0bit,  TIMER_STATUS_TIMIL0,  IRQ_TIMER0},
-       {TIMER1_id,  TIMER1bit,  TIMER_STATUS_TIMIL1,  IRQ_TIMER1},
-       {TIMER2_id,  TIMER2bit,  TIMER_STATUS_TIMIL2,  IRQ_TIMER2},
+       {TIMER0_id,  TIMER0bit,  TIMER_STATUS_TIMIL0,  IRQ_TIMER0, P_TMR0},
+       {TIMER1_id,  TIMER1bit,  TIMER_STATUS_TIMIL1,  IRQ_TIMER1, P_TMR1},
+       {TIMER2_id,  TIMER2bit,  TIMER_STATUS_TIMIL2,  IRQ_TIMER2, P_TMR2},
 #if (MAX_BLACKFIN_GPTIMERS > 3)
-       {TIMER3_id,  TIMER3bit,  TIMER_STATUS_TIMIL3,  IRQ_TIMER3},
-       {TIMER4_id,  TIMER4bit,  TIMER_STATUS_TIMIL4,  IRQ_TIMER4},
-       {TIMER5_id,  TIMER5bit,  TIMER_STATUS_TIMIL5,  IRQ_TIMER5},
-       {TIMER6_id,  TIMER6bit,  TIMER_STATUS_TIMIL6,  IRQ_TIMER6},
-       {TIMER7_id,  TIMER7bit,  TIMER_STATUS_TIMIL7,  IRQ_TIMER7},
+       {TIMER3_id,  TIMER3bit,  TIMER_STATUS_TIMIL3,  IRQ_TIMER3, P_TMR3},
+       {TIMER4_id,  TIMER4bit,  TIMER_STATUS_TIMIL4,  IRQ_TIMER4, P_TMR4},
+       {TIMER5_id,  TIMER5bit,  TIMER_STATUS_TIMIL5,  IRQ_TIMER5, P_TMR5},
+       {TIMER6_id,  TIMER6bit,  TIMER_STATUS_TIMIL6,  IRQ_TIMER6, P_TMR6},
+       {TIMER7_id,  TIMER7bit,  TIMER_STATUS_TIMIL7,  IRQ_TIMER7, P_TMR7},
 #endif
 #if (MAX_BLACKFIN_GPTIMERS > 8)
-       {TIMER8_id,  TIMER8bit,  TIMER_STATUS_TIMIL8,  IRQ_TIMER8},
-       {TIMER9_id,  TIMER9bit,  TIMER_STATUS_TIMIL9,  IRQ_TIMER9},
-       {TIMER10_id, TIMER10bit, TIMER_STATUS_TIMIL10, IRQ_TIMER10},
+       {TIMER8_id,  TIMER8bit,  TIMER_STATUS_TIMIL8,  IRQ_TIMER8, P_TMR8},
+       {TIMER9_id,  TIMER9bit,  TIMER_STATUS_TIMIL9,  IRQ_TIMER9, P_TMR9},
+       {TIMER10_id, TIMER10bit, TIMER_STATUS_TIMIL10, IRQ_TIMER10, P_TMR10},
 #if (MAX_BLACKFIN_GPTIMERS > 11)
-       {TIMER11_id, TIMER11bit, TIMER_STATUS_TIMIL11, IRQ_TIMER11},
+       {TIMER11_id, TIMER11bit, TIMER_STATUS_TIMIL11, IRQ_TIMER11, P_TMR11},
 #endif
 #endif
 };
@@ -54,6 +58,8 @@ struct bfin_tmr_state {
        struct iio_trigger *trig;
        struct bfin_timer *t;
        unsigned timer_num;
+       bool output_enable;
+       unsigned int duty;
        int irq;
 };
 
@@ -77,7 +83,7 @@ static ssize_t iio_bfin_tmr_frequency_store(struct device *dev,
 {
        struct iio_trigger *trig = to_iio_trigger(dev);
        struct bfin_tmr_state *st = trig->private_data;
-       long val;
+       unsigned long val;
        bool enabled;
        int ret;
 
@@ -99,13 +105,13 @@ static ssize_t iio_bfin_tmr_frequency_store(struct device *dev,
                goto error_ret;
 
        val = get_sclk() / val;
-       if (val <= 4) {
+       if (val <= 4 || val <= st->duty) {
                ret = -EINVAL;
                goto error_ret;
        }
 
        set_gptimer_period(st->t->id, val);
-       set_gptimer_pwidth(st->t->id, 1);
+       set_gptimer_pwidth(st->t->id, val - st->duty);
 
        if (enabled)
                enable_gptimers(st->t->bit);
@@ -176,7 +182,9 @@ static const struct iio_trigger_ops iio_bfin_tmr_trigger_ops = {
 
 static int __devinit iio_bfin_tmr_trigger_probe(struct platform_device *pdev)
 {
+       struct iio_bfin_timer_trigger_pdata *pdata = pdev->dev.platform_data;
        struct bfin_tmr_state *st;
+       unsigned int config;
        int ret;
 
        st = kzalloc(sizeof(*st), GFP_KERNEL);
@@ -220,13 +228,43 @@ static int __devinit iio_bfin_tmr_trigger_probe(struct platform_device *pdev)
                goto out4;
        }
 
-       set_gptimer_config(st->t->id, OUT_DIS | PWM_OUT | PERIOD_CNT | IRQ_ENA);
+       config = PWM_OUT | PERIOD_CNT | IRQ_ENA;
+
+       if (pdata && pdata->output_enable) {
+               unsigned long long val;
+
+               st->output_enable = true;
+
+               ret = peripheral_request(st->t->pin, st->trig->name);
+               if (ret)
+                       goto out_free_irq;
+
+               val = (unsigned long long)get_sclk() * pdata->duty_ns;
+               do_div(val, NSEC_PER_SEC);
+               st->duty = val;
+
+               /**
+                * The interrupt will be generated at the end of the period,
+                * since we want the interrupt to be generated at end of the
+                * pulse we invert both polarity and duty cycle, so that the
+                * pulse will be generated directly before the interrupt.
+                */
+               if (pdata->active_low)
+                       config |= PULSE_HI;
+       } else {
+               st->duty = 1;
+               config |= OUT_DIS;
+       }
+
+       set_gptimer_config(st->t->id, config);
 
        dev_info(&pdev->dev, "iio trigger Blackfin TMR%d, IRQ-%d",
                 st->timer_num, st->irq);
        platform_set_drvdata(pdev, st);
 
        return 0;
+out_free_irq:
+       free_irq(st->irq, st);
 out4:
        iio_trigger_unregister(st->trig);
 out2:
@@ -242,6 +280,8 @@ static int __devexit iio_bfin_tmr_trigger_remove(struct platform_device *pdev)
        struct bfin_tmr_state *st = platform_get_drvdata(pdev);
 
        disable_gptimers(st->t->bit);
+       if (st->output_enable)
+               peripheral_free(st->t->pin);
        free_irq(st->irq, st);
        iio_trigger_unregister(st->trig);
        iio_trigger_put(st->trig);

diff --git a/drivers/staging/iio/trigger/iio-trig-bfin-timer.h b/drivers/staging/iio/trigger/iio-trig-bfin-timer.h
new file mode 100644 (file)
index 0000000..c07321f
--- /dev/null
+++ b/drivers/staging/iio/trigger/iio-trig-bfin-timer.h
@@ -0,0 +1,24 @@
+#ifndef __IIO_BFIN_TIMER_TRIGGER_H__
+#define __IIO_BFIN_TIMER_TRIGGER_H__
+
+/**
+ * struct iio_bfin_timer_trigger_pdata - timer trigger platform data
+ * @output_enable: Enable external trigger pulse generation.
+ * @active_low: Whether the trigger pulse is active low.
+ * @duty_ns: Length of the trigger pulse in nanoseconds.
+ *
+ * This struct is used to configure the output pulse generation of the blackfin
+ * timer trigger. If output_enable is set to true an external trigger signal
+ * will generated on the pin corresponding to the timer. This is useful for
+ * converters which needs an external signal to start conversion. active_low and
+ * duty_ns are used to configure the type of the trigger pulse. If output_enable
+ * is set to false no external trigger pulse will be generated and active_low
+ * and duty_ns are ignored.
+ **/
+struct iio_bfin_timer_trigger_pdata {
+       bool output_enable;
+       bool active_low;
+       unsigned int duty_ns;
+};
+
+#endif