counter: new TI eQEP driver (f213729f) · Commits · EulixOS / Software / Kernel

MAINTAINERS

+6 −0

Original line number	Diff line number	Diff line
		@@ -16202,6 +16202,12 @@ S: Maintained
		F: drivers/media/platform/davinci/
		F: include/media/davinci/

		TI ENHANCED QUADRATURE ENCODER PULSE (eQEP) DRIVER
		R: David Lechner <david@lechnology.com>
		L: linux-iio@vger.kernel.org
		F: Documentation/devicetree/bindings/counter/ti-eqep.yaml
		F: drivers/counter/ti-eqep.c

		TI ETHERNET SWITCH DRIVER (CPSW)
		R: Grygorii Strashko <grygorii.strashko@ti.com>
		L: linux-omap@vger.kernel.org

drivers/bus/Kconfig

+1 −1

Original line number	Diff line number	Diff line
		@@ -152,7 +152,7 @@ config TEGRA_GMI

		config TI_PWMSS
		bool
		default y if (ARCH_OMAP2PLUS) && (PWM_TIECAP \|\| PWM_TIEHRPWM)
		default y if (ARCH_OMAP2PLUS) && (PWM_TIECAP \|\| PWM_TIEHRPWM \|\| TI_EQEP)
		help
		PWM Subsystem driver support for AM33xx SOC.

drivers/counter/Kconfig

+11 −0

Original line number	Diff line number	Diff line
		@@ -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

drivers/counter/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -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

drivers/counter/ti-eqep.c

0 → 100644

+473 −0

Original line number	Diff line number	Diff line
		// 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");