Merge tag 'ib-mfd-iio-pwm-4.11' into test

Immutable branch between MFD, IIO and PWM due for the v4.11 merge window

Pulled into IIO to allow follow up series of triggered capture for the
STM32 ADCs.

3 files changed, 352 insertions, 0 deletions

diff --git a/drivers/iio/trigger/Kconfig b/drivers/iio/trigger/Kconfig
index 809b2e7d58fa..e4d4e63434db 100644
--- a/drivers/iio/trigger/Kconfig
+++ b/drivers/iio/trigger/Kconfig
@@ -24,6 +24,15 @@ config IIO_INTERRUPT_TRIGGER
 	  To compile this driver as a module, choose M here: the
 	  module will be called iio-trig-interrupt.
 
+config IIO_STM32_TIMER_TRIGGER
+	tristate "STM32 Timer Trigger"
+	depends on (ARCH_STM32 && OF && MFD_STM32_TIMERS) || COMPILE_TEST
+	help
+	  Select this option to enable STM32 Timer Trigger
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called stm32-timer-trigger.
+
 config IIO_TIGHTLOOP_TRIGGER
 	tristate "A kthread based hammering loop trigger"
 	depends on IIO_SW_TRIGGER
diff --git a/drivers/iio/trigger/Makefile b/drivers/iio/trigger/Makefile
index aab4dc23303d..5c4ecd380653 100644
--- a/drivers/iio/trigger/Makefile
+++ b/drivers/iio/trigger/Makefile
@@ -6,5 +6,6 @@
 
 obj-$(CONFIG_IIO_HRTIMER_TRIGGER) += iio-trig-hrtimer.o
 obj-$(CONFIG_IIO_INTERRUPT_TRIGGER) += iio-trig-interrupt.o
+obj-$(CONFIG_IIO_STM32_TIMER_TRIGGER) += stm32-timer-trigger.o
 obj-$(CONFIG_IIO_SYSFS_TRIGGER) += iio-trig-sysfs.o
 obj-$(CONFIG_IIO_TIGHTLOOP_TRIGGER) += iio-trig-loop.o
diff --git a/drivers/iio/trigger/stm32-timer-trigger.c b/drivers/iio/trigger/stm32-timer-trigger.c
new file mode 100644
index 000000000000..994b96d19750
--- /dev/null
+++ b/drivers/iio/trigger/stm32-timer-trigger.c
@@ -0,0 +1,342 @@
+/*
+ * Copyright (C) STMicroelectronics 2016
+ *
+ * Author: Benjamin Gaignard <benjamin.gaignard@st.com>
+ *
+ * License terms:  GNU General Public License (GPL), version 2
+ */
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/timer/stm32-timer-trigger.h>
+#include <linux/iio/trigger.h>
+#include <linux/mfd/stm32-timers.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#define MAX_TRIGGERS 6
+
+/* List the triggers created by each timer */
+static const void *triggers_table[][MAX_TRIGGERS] = {
+	{ TIM1_TRGO, TIM1_CH1, TIM1_CH2, TIM1_CH3, TIM1_CH4,},
+	{ TIM2_TRGO, TIM2_CH1, TIM2_CH2, TIM2_CH3, TIM2_CH4,},
+	{ TIM3_TRGO, TIM3_CH1, TIM3_CH2, TIM3_CH3, TIM3_CH4,},
+	{ TIM4_TRGO, TIM4_CH1, TIM4_CH2, TIM4_CH3, TIM4_CH4,},
+	{ TIM5_TRGO, TIM5_CH1, TIM5_CH2, TIM5_CH3, TIM5_CH4,},
+	{ TIM6_TRGO,},
+	{ TIM7_TRGO,},
+	{ TIM8_TRGO, TIM8_CH1, TIM8_CH2, TIM8_CH3, TIM8_CH4,},
+	{ TIM9_TRGO, TIM9_CH1, TIM9_CH2,},
+	{ }, /* timer 10 */
+	{ }, /* timer 11 */
+	{ TIM12_TRGO, TIM12_CH1, TIM12_CH2,},
+};
+
+struct stm32_timer_trigger {
+	struct device *dev;
+	struct regmap *regmap;
+	struct clk *clk;
+	u32 max_arr;
+	const void *triggers;
+};
+
+static int stm32_timer_start(struct stm32_timer_trigger *priv,
+			     unsigned int frequency)
+{
+	unsigned long long prd, div;
+	int prescaler = 0;
+	u32 ccer, cr1;
+
+	/* Period and prescaler values depends of clock rate */
+	div = (unsigned long long)clk_get_rate(priv->clk);
+
+	do_div(div, frequency);
+
+	prd = div;
+
+	/*
+	 * Increase prescaler value until we get a result that fit
+	 * with auto reload register maximum value.
+	 */
+	while (div > priv->max_arr) {
+		prescaler++;
+		div = prd;
+		do_div(div, (prescaler + 1));
+	}
+	prd = div;
+
+	if (prescaler > MAX_TIM_PSC) {
+		dev_err(priv->dev, "prescaler exceeds the maximum value\n");
+		return -EINVAL;
+	}
+
+	/* Check if nobody else use the timer */
+	regmap_read(priv->regmap, TIM_CCER, &ccer);
+	if (ccer & TIM_CCER_CCXE)
+		return -EBUSY;
+
+	regmap_read(priv->regmap, TIM_CR1, &cr1);
+	if (!(cr1 & TIM_CR1_CEN))
+		clk_enable(priv->clk);
+
+	regmap_write(priv->regmap, TIM_PSC, prescaler);
+	regmap_write(priv->regmap, TIM_ARR, prd - 1);
+	regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_ARPE, TIM_CR1_ARPE);
+
+	/* Force master mode to update mode */
+	regmap_update_bits(priv->regmap, TIM_CR2, TIM_CR2_MMS, 0x20);
+
+	/* Make sure that registers are updated */
+	regmap_update_bits(priv->regmap, TIM_EGR, TIM_EGR_UG, TIM_EGR_UG);
+
+	/* Enable controller */
+	regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, TIM_CR1_CEN);
+
+	return 0;
+}
+
+static void stm32_timer_stop(struct stm32_timer_trigger *priv)
+{
+	u32 ccer, cr1;
+
+	regmap_read(priv->regmap, TIM_CCER, &ccer);
+	if (ccer & TIM_CCER_CCXE)
+		return;
+
+	regmap_read(priv->regmap, TIM_CR1, &cr1);
+	if (cr1 & TIM_CR1_CEN)
+		clk_disable(priv->clk);
+
+	/* Stop timer */
+	regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, 0);
+	regmap_write(priv->regmap, TIM_PSC, 0);
+	regmap_write(priv->regmap, TIM_ARR, 0);
+
+	/* Make sure that registers are updated */
+	regmap_update_bits(priv->regmap, TIM_EGR, TIM_EGR_UG, TIM_EGR_UG);
+}
+
+static ssize_t stm32_tt_store_frequency(struct device *dev,
+					struct device_attribute *attr,
+					const char *buf, size_t len)
+{
+	struct iio_trigger *trig = to_iio_trigger(dev);
+	struct stm32_timer_trigger *priv = iio_trigger_get_drvdata(trig);
+	unsigned int freq;
+	int ret;
+
+	ret = kstrtouint(buf, 10, &freq);
+	if (ret)
+		return ret;
+
+	if (freq == 0) {
+		stm32_timer_stop(priv);
+	} else {
+		ret = stm32_timer_start(priv, freq);
+		if (ret)
+			return ret;
+	}
+
+	return len;
+}
+
+static ssize_t stm32_tt_read_frequency(struct device *dev,
+				       struct device_attribute *attr, char *buf)
+{
+	struct iio_trigger *trig = to_iio_trigger(dev);
+	struct stm32_timer_trigger *priv = iio_trigger_get_drvdata(trig);
+	u32 psc, arr, cr1;
+	unsigned long long freq = 0;
+
+	regmap_read(priv->regmap, TIM_CR1, &cr1);
+	regmap_read(priv->regmap, TIM_PSC, &psc);
+	regmap_read(priv->regmap, TIM_ARR, &arr);
+
+	if (psc && arr && (cr1 & TIM_CR1_CEN)) {
+		freq = (unsigned long long)clk_get_rate(priv->clk);
+		do_div(freq, psc);
+		do_div(freq, arr);
+	}
+
+	return sprintf(buf, "%d\n", (unsigned int)freq);
+}
+
+static IIO_DEV_ATTR_SAMP_FREQ(0660,
+			      stm32_tt_read_frequency,
+			      stm32_tt_store_frequency);
+
+static char *master_mode_table[] = {
+	"reset",
+	"enable",
+	"update",
+	"compare_pulse",
+	"OC1REF",
+	"OC2REF",
+	"OC3REF",
+	"OC4REF"
+};
+
+static ssize_t stm32_tt_show_master_mode(struct device *dev,
+					 struct device_attribute *attr,
+					 char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct stm32_timer_trigger *priv = iio_priv(indio_dev);
+	u32 cr2;
+
+	regmap_read(priv->regmap, TIM_CR2, &cr2);
+	cr2 = (cr2 & TIM_CR2_MMS) >> TIM_CR2_MMS_SHIFT;
+
+	return snprintf(buf, PAGE_SIZE, "%s\n", master_mode_table[cr2]);
+}
+
+static ssize_t stm32_tt_store_master_mode(struct device *dev,
+					  struct device_attribute *attr,
+					  const char *buf, size_t len)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct stm32_timer_trigger *priv = iio_priv(indio_dev);
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(master_mode_table); i++) {
+		if (!strncmp(master_mode_table[i], buf,
+			     strlen(master_mode_table[i]))) {
+			regmap_update_bits(priv->regmap, TIM_CR2,
+					   TIM_CR2_MMS, i << TIM_CR2_MMS_SHIFT);
+			/* Make sure that registers are updated */
+			regmap_update_bits(priv->regmap, TIM_EGR,
+					   TIM_EGR_UG, TIM_EGR_UG);
+			return len;
+		}
+	}
+
+	return -EINVAL;
+}
+
+static IIO_CONST_ATTR(master_mode_available,
+	"reset enable update compare_pulse OC1REF OC2REF OC3REF OC4REF");
+
+static IIO_DEVICE_ATTR(master_mode, 0660,
+		       stm32_tt_show_master_mode,
+		       stm32_tt_store_master_mode,
+		       0);
+
+static struct attribute *stm32_trigger_attrs[] = {
+	&iio_dev_attr_sampling_frequency.dev_attr.attr,
+	&iio_dev_attr_master_mode.dev_attr.attr,
+	&iio_const_attr_master_mode_available.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group stm32_trigger_attr_group = {
+	.attrs = stm32_trigger_attrs,
+};
+
+static const struct attribute_group *stm32_trigger_attr_groups[] = {
+	&stm32_trigger_attr_group,
+	NULL,
+};
+
+static const struct iio_trigger_ops timer_trigger_ops = {
+	.owner = THIS_MODULE,
+};
+
+static int stm32_setup_iio_triggers(struct stm32_timer_trigger *priv)
+{
+	int ret;
+	const char * const *cur = priv->triggers;
+
+	while (cur && *cur) {
+		struct iio_trigger *trig;
+
+		trig = devm_iio_trigger_alloc(priv->dev, "%s", *cur);
+		if  (!trig)
+			return -ENOMEM;
+
+		trig->dev.parent = priv->dev->parent;
+		trig->ops = &timer_trigger_ops;
+
+		/*
+		 * sampling frequency and master mode attributes
+		 * should only be available on trgo trigger which
+		 * is always the first in the list.
+		 */
+		if (cur == priv->triggers)
+			trig->dev.groups = stm32_trigger_attr_groups;
+
+		iio_trigger_set_drvdata(trig, priv);
+
+		ret = devm_iio_trigger_register(priv->dev, trig);
+		if (ret)
+			return ret;
+		cur++;
+	}
+
+	return 0;
+}
+
+/**
+ * is_stm32_timer_trigger
+ * @trig: trigger to be checked
+ *
+ * return true if the trigger is a valid stm32 iio timer trigger
+ * either return false
+ */
+bool is_stm32_timer_trigger(struct iio_trigger *trig)
+{
+	return (trig->ops == &timer_trigger_ops);
+}
+EXPORT_SYMBOL(is_stm32_timer_trigger);
+
+static int stm32_timer_trigger_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct stm32_timer_trigger *priv;
+	struct stm32_timers *ddata = dev_get_drvdata(pdev->dev.parent);
+	unsigned int index;
+	int ret;
+
+	if (of_property_read_u32(dev->of_node, "reg", &index))
+		return -EINVAL;
+
+	if (index >= ARRAY_SIZE(triggers_table))
+		return -EINVAL;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+
+	if (!priv)
+		return -ENOMEM;
+
+	priv->dev = dev;
+	priv->regmap = ddata->regmap;
+	priv->clk = ddata->clk;
+	priv->max_arr = ddata->max_arr;
+	priv->triggers = triggers_table[index];
+
+	ret = stm32_setup_iio_triggers(priv);
+	if (ret)
+		return ret;
+
+	platform_set_drvdata(pdev, priv);
+
+	return 0;
+}
+
+static const struct of_device_id stm32_trig_of_match[] = {
+	{ .compatible = "st,stm32-timer-trigger", },
+	{ /* end node */ },
+};
+MODULE_DEVICE_TABLE(of, stm32_trig_of_match);
+
+static struct platform_driver stm32_timer_trigger_driver = {
+	.probe = stm32_timer_trigger_probe,
+	.driver = {
+		.name = "stm32-timer-trigger",
+		.of_match_table = stm32_trig_of_match,
+	},
+};
+module_platform_driver(stm32_timer_trigger_driver);
+
+MODULE_ALIAS("platform: stm32-timer-trigger");
+MODULE_DESCRIPTION("STMicroelectronics STM32 Timer Trigger driver");
+MODULE_LICENSE("GPL v2");