Merge branch 'ib-ti-eqep-5.4-rc1' into togreg

Immutable branch being merged in.  Created as this also involves
moving some dependencies around, outside of the counter subsystem.
It's possible it will want to be pulled into other trees.

3 files changed, 485 insertions, 0 deletions

diff --git a/drivers/counter/Kconfig b/drivers/counter/Kconfig
index 2967d0a9ff91..c80fa76bb531 100644
--- a/drivers/counter/Kconfig
+++ b/drivers/counter/Kconfig
@@ -49,6 +49,17 @@ config STM32_LPTIMER_CNT
 	  To compile this driver as a module, choose M here: the
 	  module will be called stm32-lptimer-cnt.
 
+config TI_EQEP
+	tristate "TI eQEP counter driver"
+	depends on (SOC_AM33XX || COMPILE_TEST)
+	select REGMAP_MMIO
+	help
+	  Select this option to enable the Texas Instruments Enhanced Quadrature
+	  Encoder Pulse (eQEP) counter driver.
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called ti-eqep.
+
 config FTM_QUADDEC
 	tristate "Flex Timer Module Quadrature decoder driver"
 	depends on HAS_IOMEM && OF
diff --git a/drivers/counter/Makefile b/drivers/counter/Makefile
index 40d35522937d..55142d1f4c43 100644
--- a/drivers/counter/Makefile
+++ b/drivers/counter/Makefile
@@ -8,4 +8,5 @@ obj-$(CONFIG_COUNTER) += counter.o
 obj-$(CONFIG_104_QUAD_8)	+= 104-quad-8.o
 obj-$(CONFIG_STM32_TIMER_CNT)	+= stm32-timer-cnt.o
 obj-$(CONFIG_STM32_LPTIMER_CNT)	+= stm32-lptimer-cnt.o
+obj-$(CONFIG_TI_EQEP)		+= ti-eqep.o
 obj-$(CONFIG_FTM_QUADDEC)	+= ftm-quaddec.o
diff --git a/drivers/counter/ti-eqep.c b/drivers/counter/ti-eqep.c
new file mode 100644
index 000000000000..4b3ef2449c06
--- /dev/null
+++ b/drivers/counter/ti-eqep.c
@@ -0,0 +1,473 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2019 David Lechner <david@lechnology.com>
+ *
+ * Counter driver for Texas Instruments Enhanced Quadrature Encoder Pulse (eQEP)
+ */
+
+#include <linux/bitops.h>
+#include <linux/counter.h>
+#include <linux/kernel.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+
+/* 32-bit registers */
+#define QPOSCNT		0x0
+#define QPOSINIT	0x4
+#define QPOSMAX		0x8
+#define QPOSCMP		0xc
+#define QPOSILAT	0x10
+#define QPOSSLAT	0x14
+#define QPOSLAT		0x18
+#define QUTMR		0x1c
+#define QUPRD		0x20
+
+/* 16-bit registers */
+#define QWDTMR		0x0	/* 0x24 */
+#define QWDPRD		0x2	/* 0x26 */
+#define QDECCTL		0x4	/* 0x28 */
+#define QEPCTL		0x6	/* 0x2a */
+#define QCAPCTL		0x8	/* 0x2c */
+#define QPOSCTL		0xa	/* 0x2e */
+#define QEINT		0xc	/* 0x30 */
+#define QFLG		0xe	/* 0x32 */
+#define QCLR		0x10	/* 0x34 */
+#define QFRC		0x12	/* 0x36 */
+#define QEPSTS		0x14	/* 0x38 */
+#define QCTMR		0x16	/* 0x3a */
+#define QCPRD		0x18	/* 0x3c */
+#define QCTMRLAT	0x1a	/* 0x3e */
+#define QCPRDLAT	0x1c	/* 0x40 */
+
+#define QDECCTL_QSRC_SHIFT	14
+#define QDECCTL_QSRC		GENMASK(15, 14)
+#define QDECCTL_SOEN		BIT(13)
+#define QDECCTL_SPSEL		BIT(12)
+#define QDECCTL_XCR		BIT(11)
+#define QDECCTL_SWAP		BIT(10)
+#define QDECCTL_IGATE		BIT(9)
+#define QDECCTL_QAP		BIT(8)
+#define QDECCTL_QBP		BIT(7)
+#define QDECCTL_QIP		BIT(6)
+#define QDECCTL_QSP		BIT(5)
+
+#define QEPCTL_FREE_SOFT	GENMASK(15, 14)
+#define QEPCTL_PCRM		GENMASK(13, 12)
+#define QEPCTL_SEI		GENMASK(11, 10)
+#define QEPCTL_IEI		GENMASK(9, 8)
+#define QEPCTL_SWI		BIT(7)
+#define QEPCTL_SEL		BIT(6)
+#define QEPCTL_IEL		GENMASK(5, 4)
+#define QEPCTL_PHEN		BIT(3)
+#define QEPCTL_QCLM		BIT(2)
+#define QEPCTL_UTE		BIT(1)
+#define QEPCTL_WDE		BIT(0)
+
+/* EQEP Inputs */
+enum {
+	TI_EQEP_SIGNAL_QEPA,	/* QEPA/XCLK */
+	TI_EQEP_SIGNAL_QEPB,	/* QEPB/XDIR */
+};
+
+/* Position Counter Input Modes */
+enum {
+	TI_EQEP_COUNT_FUNC_QUAD_COUNT,
+	TI_EQEP_COUNT_FUNC_DIR_COUNT,
+	TI_EQEP_COUNT_FUNC_UP_COUNT,
+	TI_EQEP_COUNT_FUNC_DOWN_COUNT,
+};
+
+enum {
+	TI_EQEP_SYNAPSE_ACTION_BOTH_EDGES,
+	TI_EQEP_SYNAPSE_ACTION_RISING_EDGE,
+	TI_EQEP_SYNAPSE_ACTION_NONE,
+};
+
+struct ti_eqep_cnt {
+	struct counter_device counter;
+	struct regmap *regmap32;
+	struct regmap *regmap16;
+};
+
+static int ti_eqep_count_read(struct counter_device *counter,
+			      struct counter_count *count,
+			      struct counter_count_read_value *val)
+{
+	struct ti_eqep_cnt *priv = counter->priv;
+	u32 cnt;
+
+	regmap_read(priv->regmap32, QPOSCNT, &cnt);
+	counter_count_read_value_set(val, COUNTER_COUNT_POSITION, &cnt);
+
+	return 0;
+}
+
+static int ti_eqep_count_write(struct counter_device *counter,
+			       struct counter_count *count,
+			       struct counter_count_write_value *val)
+{
+	struct ti_eqep_cnt *priv = counter->priv;
+	u32 cnt, max;
+	int err;
+
+	err = counter_count_write_value_get(&cnt, COUNTER_COUNT_POSITION, val);
+	if (err)
+		return err;
+
+	regmap_read(priv->regmap32, QPOSMAX, &max);
+	if (cnt > max)
+		return -EINVAL;
+
+	return regmap_write(priv->regmap32, QPOSCNT, cnt);
+}
+
+static int ti_eqep_function_get(struct counter_device *counter,
+				struct counter_count *count, size_t *function)
+{
+	struct ti_eqep_cnt *priv = counter->priv;
+	u32 qdecctl;
+
+	regmap_read(priv->regmap16, QDECCTL, &qdecctl);
+	*function = (qdecctl & QDECCTL_QSRC) >> QDECCTL_QSRC_SHIFT;
+
+	return 0;
+}
+
+static int ti_eqep_function_set(struct counter_device *counter,
+				struct counter_count *count, size_t function)
+{
+	struct ti_eqep_cnt *priv = counter->priv;
+
+	return regmap_write_bits(priv->regmap16, QDECCTL, QDECCTL_QSRC,
+				 function << QDECCTL_QSRC_SHIFT);
+}
+
+static int ti_eqep_action_get(struct counter_device *counter,
+			      struct counter_count *count,
+			      struct counter_synapse *synapse, size_t *action)
+{
+	struct ti_eqep_cnt *priv = counter->priv;
+	size_t function;
+	u32 qdecctl;
+	int err;
+
+	err = ti_eqep_function_get(counter, count, &function);
+	if (err)
+		return err;
+
+	switch (function) {
+	case TI_EQEP_COUNT_FUNC_QUAD_COUNT:
+		/* In quadrature mode, the rising and falling edge of both
+		 * QEPA and QEPB trigger QCLK.
+		 */
+		*action = TI_EQEP_SYNAPSE_ACTION_BOTH_EDGES;
+		break;
+	case TI_EQEP_COUNT_FUNC_DIR_COUNT:
+		/* In direction-count mode only rising edge of QEPA is counted
+		 * and QEPB gives direction.
+		 */
+		switch (synapse->signal->id) {
+		case TI_EQEP_SIGNAL_QEPA:
+			*action = TI_EQEP_SYNAPSE_ACTION_RISING_EDGE;
+			break;
+		default:
+			*action = TI_EQEP_SYNAPSE_ACTION_NONE;
+			break;
+		}
+		break;
+	case TI_EQEP_COUNT_FUNC_UP_COUNT:
+	case TI_EQEP_COUNT_FUNC_DOWN_COUNT:
+		/* In up/down-count modes only QEPA is counted and QEPB is not
+		 * used.
+		 */
+		switch (synapse->signal->id) {
+		case TI_EQEP_SIGNAL_QEPA:
+			err = regmap_read(priv->regmap16, QDECCTL, &qdecctl);
+			if (err)
+				return err;
+
+			if (qdecctl & QDECCTL_XCR)
+				*action = TI_EQEP_SYNAPSE_ACTION_BOTH_EDGES;
+			else
+				*action = TI_EQEP_SYNAPSE_ACTION_RISING_EDGE;
+			break;
+		default:
+			*action = TI_EQEP_SYNAPSE_ACTION_NONE;
+			break;
+		}
+		break;
+	}
+
+	return 0;
+}
+
+static const struct counter_ops ti_eqep_counter_ops = {
+	.count_read	= ti_eqep_count_read,
+	.count_write	= ti_eqep_count_write,
+	.function_get	= ti_eqep_function_get,
+	.function_set	= ti_eqep_function_set,
+	.action_get	= ti_eqep_action_get,
+};
+
+static ssize_t ti_eqep_position_ceiling_read(struct counter_device *counter,
+					     struct counter_count *count,
+					     void *ext_priv, char *buf)
+{
+	struct ti_eqep_cnt *priv = counter->priv;
+	u32 qposmax;
+
+	regmap_read(priv->regmap32, QPOSMAX, &qposmax);
+
+	return sprintf(buf, "%u\n", qposmax);
+}
+
+static ssize_t ti_eqep_position_ceiling_write(struct counter_device *counter,
+					      struct counter_count *count,
+					      void *ext_priv, const char *buf,
+					      size_t len)
+{
+	struct ti_eqep_cnt *priv = counter->priv;
+	int err;
+	u32 res;
+
+	err = kstrtouint(buf, 0, &res);
+	if (err < 0)
+		return err;
+
+	regmap_write(priv->regmap32, QPOSMAX, res);
+
+	return len;
+}
+
+static ssize_t ti_eqep_position_floor_read(struct counter_device *counter,
+					   struct counter_count *count,
+					   void *ext_priv, char *buf)
+{
+	struct ti_eqep_cnt *priv = counter->priv;
+	u32 qposinit;
+
+	regmap_read(priv->regmap32, QPOSINIT, &qposinit);
+
+	return sprintf(buf, "%u\n", qposinit);
+}
+
+static ssize_t ti_eqep_position_floor_write(struct counter_device *counter,
+					    struct counter_count *count,
+					    void *ext_priv, const char *buf,
+					    size_t len)
+{
+	struct ti_eqep_cnt *priv = counter->priv;
+	int err;
+	u32 res;
+
+	err = kstrtouint(buf, 0, &res);
+	if (err < 0)
+		return err;
+
+	regmap_write(priv->regmap32, QPOSINIT, res);
+
+	return len;
+}
+
+static ssize_t ti_eqep_position_enable_read(struct counter_device *counter,
+					    struct counter_count *count,
+					    void *ext_priv, char *buf)
+{
+	struct ti_eqep_cnt *priv = counter->priv;
+	u32 qepctl;
+
+	regmap_read(priv->regmap16, QEPCTL, &qepctl);
+
+	return sprintf(buf, "%u\n", !!(qepctl & QEPCTL_PHEN));
+}
+
+static ssize_t ti_eqep_position_enable_write(struct counter_device *counter,
+					     struct counter_count *count,
+					     void *ext_priv, const char *buf,
+					     size_t len)
+{
+	struct ti_eqep_cnt *priv = counter->priv;
+	int err;
+	bool res;
+
+	err = kstrtobool(buf, &res);
+	if (err < 0)
+		return err;
+
+	regmap_write_bits(priv->regmap16, QEPCTL, QEPCTL_PHEN, res ? -1 : 0);
+
+	return len;
+}
+
+static struct counter_count_ext ti_eqep_position_ext[] = {
+	{
+		.name	= "ceiling",
+		.read	= ti_eqep_position_ceiling_read,
+		.write	= ti_eqep_position_ceiling_write,
+	},
+	{
+		.name	= "floor",
+		.read	= ti_eqep_position_floor_read,
+		.write	= ti_eqep_position_floor_write,
+	},
+	{
+		.name	= "enable",
+		.read	= ti_eqep_position_enable_read,
+		.write	= ti_eqep_position_enable_write,
+	},
+};
+
+static struct counter_signal ti_eqep_signals[] = {
+	[TI_EQEP_SIGNAL_QEPA] = {
+		.id = TI_EQEP_SIGNAL_QEPA,
+		.name = "QEPA"
+	},
+	[TI_EQEP_SIGNAL_QEPB] = {
+		.id = TI_EQEP_SIGNAL_QEPB,
+		.name = "QEPB"
+	},
+};
+
+static const enum counter_count_function ti_eqep_position_functions[] = {
+	[TI_EQEP_COUNT_FUNC_QUAD_COUNT]	= COUNTER_COUNT_FUNCTION_QUADRATURE_X4,
+	[TI_EQEP_COUNT_FUNC_DIR_COUNT]	= COUNTER_COUNT_FUNCTION_PULSE_DIRECTION,
+	[TI_EQEP_COUNT_FUNC_UP_COUNT]	= COUNTER_COUNT_FUNCTION_INCREASE,
+	[TI_EQEP_COUNT_FUNC_DOWN_COUNT]	= COUNTER_COUNT_FUNCTION_DECREASE,
+};
+
+static const enum counter_synapse_action ti_eqep_position_synapse_actions[] = {
+	[TI_EQEP_SYNAPSE_ACTION_BOTH_EDGES]	= COUNTER_SYNAPSE_ACTION_BOTH_EDGES,
+	[TI_EQEP_SYNAPSE_ACTION_RISING_EDGE]	= COUNTER_SYNAPSE_ACTION_RISING_EDGE,
+	[TI_EQEP_SYNAPSE_ACTION_NONE]		= COUNTER_SYNAPSE_ACTION_NONE,
+};
+
+static struct counter_synapse ti_eqep_position_synapses[] = {
+	{
+		.actions_list	= ti_eqep_position_synapse_actions,
+		.num_actions	= ARRAY_SIZE(ti_eqep_position_synapse_actions),
+		.signal		= &ti_eqep_signals[TI_EQEP_SIGNAL_QEPA],
+	},
+	{
+		.actions_list	= ti_eqep_position_synapse_actions,
+		.num_actions	= ARRAY_SIZE(ti_eqep_position_synapse_actions),
+		.signal		= &ti_eqep_signals[TI_EQEP_SIGNAL_QEPB],
+	},
+};
+
+static struct counter_count ti_eqep_counts[] = {
+	{
+		.id		= 0,
+		.name		= "QPOSCNT",
+		.functions_list	= ti_eqep_position_functions,
+		.num_functions	= ARRAY_SIZE(ti_eqep_position_functions),
+		.synapses	= ti_eqep_position_synapses,
+		.num_synapses	= ARRAY_SIZE(ti_eqep_position_synapses),
+		.ext		= ti_eqep_position_ext,
+		.num_ext	= ARRAY_SIZE(ti_eqep_position_ext),
+	},
+};
+
+static const struct regmap_config ti_eqep_regmap32_config = {
+	.name = "32-bit",
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = 4,
+	.max_register = 0x24,
+};
+
+static const struct regmap_config ti_eqep_regmap16_config = {
+	.name = "16-bit",
+	.reg_bits = 16,
+	.val_bits = 16,
+	.reg_stride = 2,
+	.max_register = 0x1e,
+};
+
+static int ti_eqep_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct ti_eqep_cnt *priv;
+	void __iomem *base;
+	int err;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	priv->regmap32 = devm_regmap_init_mmio(dev, base,
+					       &ti_eqep_regmap32_config);
+	if (IS_ERR(priv->regmap32))
+		return PTR_ERR(priv->regmap32);
+
+	priv->regmap16 = devm_regmap_init_mmio(dev, base + 0x24,
+					       &ti_eqep_regmap16_config);
+	if (IS_ERR(priv->regmap16))
+		return PTR_ERR(priv->regmap16);
+
+	priv->counter.name = dev_name(dev);
+	priv->counter.parent = dev;
+	priv->counter.ops = &ti_eqep_counter_ops;
+	priv->counter.counts = ti_eqep_counts;
+	priv->counter.num_counts = ARRAY_SIZE(ti_eqep_counts);
+	priv->counter.signals = ti_eqep_signals;
+	priv->counter.num_signals = ARRAY_SIZE(ti_eqep_signals);
+	priv->counter.priv = priv;
+
+	platform_set_drvdata(pdev, priv);
+
+	/*
+	 * Need to make sure power is turned on. On AM33xx, this comes from the
+	 * parent PWMSS bus driver. On AM17xx, this comes from the PSC power
+	 * domain.
+	 */
+	pm_runtime_enable(dev);
+	pm_runtime_get_sync(dev);
+
+	err = counter_register(&priv->counter);
+	if (err < 0) {
+		pm_runtime_put_sync(dev);
+		pm_runtime_disable(dev);
+		return err;
+	}
+
+	return 0;
+}
+
+static int ti_eqep_remove(struct platform_device *pdev)
+{
+	struct ti_eqep_cnt *priv = platform_get_drvdata(pdev);
+	struct device *dev = &pdev->dev;
+
+	counter_unregister(&priv->counter);
+	pm_runtime_put_sync(dev),
+	pm_runtime_disable(dev);
+
+	return 0;
+}
+
+static const struct of_device_id ti_eqep_of_match[] = {
+	{ .compatible = "ti,am3352-eqep", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, ti_eqep_of_match);
+
+static struct platform_driver ti_eqep_driver = {
+	.probe = ti_eqep_probe,
+	.remove = ti_eqep_remove,
+	.driver = {
+		.name = "ti-eqep-cnt",
+		.of_match_table = ti_eqep_of_match,
+	},
+};
+module_platform_driver(ti_eqep_driver);
+
+MODULE_AUTHOR("David Lechner <david@lechnology.com>");
+MODULE_DESCRIPTION("TI eQEP counter driver");
+MODULE_LICENSE("GPL v2");