[PATCH v9 4/5] Input: cs40l50 - Add support for the CS40L50 haptic driver

[James Ogletree <jogletre@opensource.cirrus.com>]

Introduce support for Cirrus Logic Device CS40L50: a
haptic driver with waveform memory, integrated DSP,
and closed-loop algorithms.

The input driver provides the interface for control of
haptic effects through the device.

Signed-off-by: James Ogletree <jogletre@opensource.cirrus.com>
---
v7: v8: v9:
Please advise if playback stop is still misused with respect to not
specifying an effect ID. The device can only play one effect at a
time, but setting max effects for the EVIOCGEFFECTS ioctl to 1 would
restrict the number of uploads to 1 as well. So I'm unsure of the correct
approach here.

 MAINTAINERS                        |   1 +
 drivers/input/misc/Kconfig         |  10 +
 drivers/input/misc/Makefile        |   1 +
 drivers/input/misc/cs40l50-vibra.c | 578 +++++++++++++++++++++++++++++
 4 files changed, 590 insertions(+)
 create mode 100644 drivers/input/misc/cs40l50-vibra.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 69a9e0a3b968..24cfb4f017bb 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4940,6 +4940,7 @@ M:	Ben Bright <ben.bright@cirrus.com>
 L:	patches@opensource.cirrus.com
 S:	Supported
 F:	Documentation/devicetree/bindings/input/cirrus,cs40l50.yaml
+F:	drivers/input/misc/cs40l*
 F:	drivers/mfd/cs40l*
 F:	include/linux/mfd/cs40l*
 
diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig
index 6ba984d7f0b1..ee45dbb0636e 100644
--- a/drivers/input/misc/Kconfig
+++ b/drivers/input/misc/Kconfig
@@ -140,6 +140,16 @@ config INPUT_BMA150
 	  To compile this driver as a module, choose M here: the
 	  module will be called bma150.
 
+config INPUT_CS40L50_VIBRA
+	tristate "CS40L50 Haptic Driver support"
+	depends on MFD_CS40L50_CORE
+	help
+	  Say Y here to enable support for Cirrus Logic's CS40L50
+	  haptic driver.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called cs40l50-vibra.
+
 config INPUT_E3X0_BUTTON
 	tristate "NI Ettus Research USRP E3xx Button support."
 	default n
diff --git a/drivers/input/misc/Makefile b/drivers/input/misc/Makefile
index 04296a4abe8e..88279de6d3d5 100644
--- a/drivers/input/misc/Makefile
+++ b/drivers/input/misc/Makefile
@@ -28,6 +28,7 @@ obj-$(CONFIG_INPUT_CMA3000)		+= cma3000_d0x.o
 obj-$(CONFIG_INPUT_CMA3000_I2C)		+= cma3000_d0x_i2c.o
 obj-$(CONFIG_INPUT_COBALT_BTNS)		+= cobalt_btns.o
 obj-$(CONFIG_INPUT_CPCAP_PWRBUTTON)	+= cpcap-pwrbutton.o
+obj-$(CONFIG_INPUT_CS40L50_VIBRA)	+= cs40l50-vibra.o
 obj-$(CONFIG_INPUT_DA7280_HAPTICS)	+= da7280.o
 obj-$(CONFIG_INPUT_DA9052_ONKEY)	+= da9052_onkey.o
 obj-$(CONFIG_INPUT_DA9055_ONKEY)	+= da9055_onkey.o
diff --git a/drivers/input/misc/cs40l50-vibra.c b/drivers/input/misc/cs40l50-vibra.c
new file mode 100644
index 000000000000..c7e68862bbfe
--- /dev/null
+++ b/drivers/input/misc/cs40l50-vibra.c
@@ -0,0 +1,578 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * CS40L50 Advanced Haptic Driver with waveform memory,
+ * integrated DSP, and closed-loop algorithms
+ *
+ * Copyright 2024 Cirrus Logic, Inc.
+ *
+ * Author: James Ogletree <james.ogletree@cirrus.com>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/input.h>
+#include <linux/mfd/cs40l50.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+
+/* Wavetables */
+#define CS40L50_RAM_INDEX_START		0x1000000
+#define CS40L50_RAM_INDEX_END		0x100007F
+#define CS40L50_RTH_INDEX_START		0x1400000
+#define CS40L50_RTH_INDEX_END		0x1400001
+#define CS40L50_ROM_INDEX_START		0x1800000
+#define CS40L50_ROM_INDEX_END		0x180001A
+#define CS40L50_TYPE_PCM		8
+#define CS40L50_TYPE_PWLE		12
+#define CS40L50_PCM_ID			0x0
+#define CS40L50_OWT_CUSTOM_DATA_SIZE	2
+
+/* DSP */
+#define CS40L50_GPIO_BASE		0x2804140
+#define CS40L50_OWT_BASE		0x2805C34
+#define CS40L50_OWT_SIZE		0x2805C38
+#define CS40L50_OWT_NEXT		0x2805C3C
+
+/* GPIO */
+#define CS40L50_GPIO_NUM_MASK		GENMASK(14, 12)
+#define CS40L50_GPIO_EDGE_MASK		BIT(15)
+#define CS40L50_GPIO_MAPPING_NONE	0
+#define CS40L50_GPIO_DISABLE		0x1FF
+
+enum vibra_bank_type {
+	WVFRM_BANK_RAM,
+	WVFRM_BANK_ROM,
+	WVFRM_BANK_OWT,
+	WVFRM_BANK_NUM,
+};
+
+/* Describes an area in DSP memory populated by effects */
+struct vibra_bank {
+	enum vibra_bank_type bank;
+	u32 base_index;
+	u32 max_index;
+};
+
+struct vibra_effect {
+	enum vibra_bank_type bank;
+	struct list_head list;
+	u32 gpio_reg;
+	u32 index;
+	int id;
+};
+
+/* Describes haptic interface of loaded DSP firmware */
+struct vibra_dsp {
+	struct vibra_bank *banks;
+	u32 gpio_base_reg;
+	u32 owt_offset_reg;
+	u32 owt_size_reg;
+	u32 owt_base_reg;
+	int (*write)(struct device *dev, struct regmap *regmap, u32 val);
+	u32 push_owt_cmd;
+	u32 delete_owt_cmd;
+	u32 stop_cmd;
+};
+
+/* Describes configuration and state of haptic operations */
+struct vibra_info {
+	struct device *dev;
+	struct regmap *regmap;
+	struct input_dev *input;
+	struct mutex lock;
+	struct workqueue_struct *vibe_wq;
+	struct list_head effect_head;
+	struct vibra_dsp dsp;
+};
+
+struct vibra_work {
+	struct vibra_info *info;
+	struct ff_effect *effect;
+	struct work_struct work;
+	s16 *custom_data;
+	int custom_len;
+	int count;
+	int error;
+};
+
+static struct vibra_bank cs40l50_banks[] = {
+	{
+		.bank =		WVFRM_BANK_RAM,
+		.base_index =	CS40L50_RAM_INDEX_START,
+		.max_index =	CS40L50_RAM_INDEX_END,
+	},
+	{
+		.bank =		WVFRM_BANK_ROM,
+		.base_index =	CS40L50_ROM_INDEX_START,
+		.max_index =	CS40L50_ROM_INDEX_END,
+	},
+	{
+		.bank =		WVFRM_BANK_OWT,
+		.base_index =	CS40L50_RTH_INDEX_START,
+		.max_index =	CS40L50_RTH_INDEX_END,
+	},
+};
+
+static struct vibra_dsp cs40l50_dsp = {
+	.banks =		cs40l50_banks,
+	.gpio_base_reg =	CS40L50_GPIO_BASE,
+	.owt_base_reg =		CS40L50_OWT_BASE,
+	.owt_offset_reg =	CS40L50_OWT_NEXT,
+	.owt_size_reg =		CS40L50_OWT_SIZE,
+
+	.push_owt_cmd =		CS40L50_OWT_PUSH,
+	.delete_owt_cmd =	CS40L50_OWT_DELETE,
+	.stop_cmd =		CS40L50_STOP_PLAYBACK,
+
+	.write =		cs40l50_dsp_write,
+};
+
+static struct vibra_effect *vibra_find_effect(int id, struct list_head *effect_head)
+{
+	struct vibra_effect *effect;
+
+	list_for_each_entry(effect, effect_head, list)
+		if (effect->id == id)
+			return effect;
+
+	return NULL;
+}
+
+static int vibra_effect_bank_set(struct vibra_work *work_data,
+				 struct vibra_effect *effect)
+{
+	s16 bank = work_data->custom_data[0] & 0xffffu;
+
+	if (bank >= WVFRM_BANK_NUM) {
+		dev_err(work_data->info->dev, "Invalid waveform bank: %d\n", bank);
+		return -EINVAL;
+	}
+
+	if (work_data->custom_len > CS40L50_OWT_CUSTOM_DATA_SIZE)
+		effect->bank = WVFRM_BANK_OWT;
+	else
+		effect->bank = bank;
+
+	return 0;
+}
+
+static int vibra_effect_gpio_mapping_set(struct vibra_work *work_data,
+				    struct vibra_effect *effect)
+{
+	u16 button = work_data->effect->trigger.button;
+	struct vibra_info *info = work_data->info;
+	u32 gpio_num, gpio_edge;
+
+	if (button) {
+		gpio_num = FIELD_GET(CS40L50_GPIO_NUM_MASK, button);
+		gpio_edge = FIELD_GET(CS40L50_GPIO_EDGE_MASK, button);
+		effect->gpio_reg = info->dsp.gpio_base_reg + (gpio_num * 8) - gpio_edge;
+
+		return regmap_write(info->regmap, effect->gpio_reg, button);
+	}
+
+	effect->gpio_reg = CS40L50_GPIO_MAPPING_NONE;
+
+	return 0;
+}
+
+static int vibra_effect_index_set(struct vibra_work *work_data,
+				  struct vibra_effect *effect)
+{
+	struct vibra_info *info = work_data->info;
+	struct vibra_effect *owt_effect;
+	u32 base_index, max_index;
+
+	base_index = info->dsp.banks[effect->bank].base_index;
+	max_index = info->dsp.banks[effect->bank].max_index;
+
+	effect->index = base_index;
+
+	switch (effect->bank) {
+	case WVFRM_BANK_OWT:
+		list_for_each_entry(owt_effect, &info->effect_head, list)
+			if (owt_effect->bank == WVFRM_BANK_OWT)
+				effect->index++;
+		break;
+	case WVFRM_BANK_ROM:
+	case WVFRM_BANK_RAM:
+		effect->index += work_data->custom_data[1] & 0xffffu;
+		break;
+	default:
+		dev_err(info->dev, "Bank not supported: %d\n", effect->bank);
+		return -EINVAL;
+	}
+
+	if (effect->index > max_index || effect->index < base_index) {
+		dev_err(info->dev, "Index out of bounds: %u\n", effect->index);
+		return -ENOSPC;
+	}
+
+	return 0;
+}
+
+/* Describes a header for an OWT effect */
+struct owt_header {
+	u32 type;
+	u32 data_words;
+	u32 offset;
+} __packed;
+
+static int vibra_upload_owt(struct vibra_work *work_data)
+{
+	u32 len = 2 * work_data->custom_len, wt_offset, wt_size;
+	struct vibra_info *info = work_data->info;
+	struct owt_header header;
+	u8 *out_data;
+	int error;
+
+	error = regmap_read(info->regmap, info->dsp.owt_size_reg, &wt_size);
+	if (error)
+		return error;
+
+	if ((wt_size * sizeof(u32)) < sizeof(header) + len) {
+		dev_err(info->dev, "No space in OWT bank for effect\n");
+		return -ENOSPC;
+	}
+
+	out_data = kzalloc(sizeof(header) + len, GFP_KERNEL);
+	if (!out_data)
+		return -ENOMEM;
+
+	header.type = work_data->custom_data[0] == CS40L50_PCM_ID ? CS40L50_TYPE_PCM :
+								    CS40L50_TYPE_PWLE;
+	header.offset = sizeof(header) / sizeof(u32);
+	header.data_words = len / sizeof(u32);
+
+	memcpy(out_data, &header, sizeof(header));
+	memcpy(out_data + sizeof(header), work_data->custom_data, len);
+
+	error = regmap_read(info->regmap, info->dsp.owt_offset_reg, &wt_offset);
+	if (error)
+		goto err_free;
+
+	error = regmap_bulk_write(info->regmap, info->dsp.owt_base_reg +
+				  (wt_offset * sizeof(u32)), out_data,
+				  sizeof(header) + len);
+	if (error)
+		goto err_free;
+
+	error = info->dsp.write(info->dev, info->regmap, info->dsp.push_owt_cmd);
+err_free:
+	kfree(out_data);
+
+	return error;
+}
+
+static void vibra_add_worker(struct work_struct *work)
+{
+	struct vibra_work *work_data = container_of(work, struct vibra_work, work);
+	struct vibra_info *info = work_data->info;
+	struct vibra_effect *effect;
+	bool is_new = false;
+	int error;
+
+	error = pm_runtime_resume_and_get(info->dev);
+	if (error < 0)
+		goto err;
+
+	mutex_lock(&info->lock);
+
+	/* Update effect if already present, otherwise create new effect */
+	effect = vibra_find_effect(work_data->effect->id, &info->effect_head);
+	if (!effect) {
+		effect = kzalloc(sizeof(*effect), GFP_KERNEL);
+		if (!effect) {
+			error = -ENOMEM;
+			goto err_mutex;
+		}
+
+		effect->id = work_data->effect->id;
+		is_new = true;
+	}
+
+	error = vibra_effect_bank_set(work_data, effect);
+	if (error)
+		goto err_free;
+
+	error = vibra_effect_index_set(work_data, effect);
+	if (error)
+		goto err_free;
+
+	error = vibra_effect_gpio_mapping_set(work_data, effect);
+	if (error)
+		goto err_free;
+
+	if (effect->bank == WVFRM_BANK_OWT)
+		error = vibra_upload_owt(work_data);
+err_free:
+	if (is_new) {
+		if (error)
+			kfree(effect);
+		else
+			list_add(&effect->list, &info->effect_head);
+	}
+err_mutex:
+	mutex_unlock(&info->lock);
+
+	pm_runtime_mark_last_busy(info->dev);
+	pm_runtime_put_autosuspend(info->dev);
+err:
+	work_data->error = error;
+}
+
+static int vibra_add(struct input_dev *dev, struct ff_effect *effect,
+		     struct ff_effect *old)
+{
+	struct ff_periodic_effect *periodic = &effect->u.periodic;
+	struct vibra_info *info = input_get_drvdata(dev);
+	u32 len = effect->u.periodic.custom_len;
+	struct vibra_work work_data;
+
+	if (effect->type != FF_PERIODIC || periodic->waveform != FF_CUSTOM) {
+		dev_err(info->dev, "Type (%#X) or waveform (%#X) unsupported\n",
+			effect->type, periodic->waveform);
+		return -EINVAL;
+	}
+
+	work_data.custom_data = kcalloc(len, sizeof(s16), GFP_KERNEL);
+	if (!work_data.custom_data)
+		return -ENOMEM;
+
+	if (copy_from_user(work_data.custom_data, effect->u.periodic.custom_data,
+			   sizeof(s16) * len)) {
+		work_data.error = -EFAULT;
+		goto err_free;
+	}
+
+	work_data.custom_len = len;
+	work_data.info = info;
+	work_data.effect = effect;
+	INIT_WORK(&work_data.work, vibra_add_worker);
+
+	/* Push to the workqueue to serialize with playbacks */
+	queue_work(info->vibe_wq, &work_data.work);
+	flush_work(&work_data.work);
+err_free:
+	kfree(work_data.custom_data);
+
+	return work_data.error;
+}
+
+static void vibra_start_worker(struct work_struct *work)
+{
+	struct vibra_work *work_data = container_of(work, struct vibra_work, work);
+	struct vibra_info *info = work_data->info;
+	struct vibra_effect *start_effect;
+
+	if (pm_runtime_resume_and_get(info->dev) < 0)
+		goto err_free;
+
+	mutex_lock(&info->lock);
+
+	start_effect = vibra_find_effect(work_data->effect->id, &info->effect_head);
+	if (start_effect) {
+		while (--work_data->count >= 0) {
+			info->dsp.write(info->dev, info->regmap, start_effect->index);
+			usleep_range(work_data->effect->replay.length,
+				     work_data->effect->replay.length + 100);
+		}
+	}
+
+	mutex_unlock(&info->lock);
+
+	if (!start_effect)
+		dev_err(info->dev, "Effect to play not found\n");
+
+	pm_runtime_mark_last_busy(info->dev);
+	pm_runtime_put_autosuspend(info->dev);
+err_free:
+	kfree(work_data);
+}
+
+static void vibra_stop_worker(struct work_struct *work)
+{
+	struct vibra_work *work_data = container_of(work, struct vibra_work, work);
+	struct vibra_info *info = work_data->info;
+
+	if (pm_runtime_resume_and_get(info->dev) < 0)
+		return;
+
+	mutex_lock(&info->lock);
+
+	info->dsp.write(info->dev, info->regmap, info->dsp.stop_cmd);
+
+	mutex_unlock(&info->lock);
+
+	pm_runtime_mark_last_busy(info->dev);
+	pm_runtime_put_autosuspend(info->dev);
+
+	kfree(work_data);
+}
+
+static int vibra_playback(struct input_dev *dev, int effect_id, int val)
+{
+	struct vibra_info *info = input_get_drvdata(dev);
+	struct vibra_work *work_data;
+
+	work_data = kzalloc(sizeof(*work_data), GFP_ATOMIC);
+	if (!work_data)
+		return -ENOMEM;
+
+	work_data->info = info;
+
+	if (val > 0) {
+		work_data->effect = &dev->ff->effects[effect_id];
+		work_data->count = val;
+		INIT_WORK(&work_data->work, vibra_start_worker);
+	} else {
+		/* Stop the amplifier as device drives only one effect */
+		INIT_WORK(&work_data->work, vibra_stop_worker);
+	}
+
+	queue_work(info->vibe_wq, &work_data->work);
+
+	return 0;
+}
+
+static void vibra_erase_worker(struct work_struct *work)
+{
+	struct vibra_work *work_data = container_of(work, struct vibra_work, work);
+	struct vibra_effect *owt_effect, *erase_effect;
+	struct vibra_info *info = work_data->info;
+	int error;
+
+	error = pm_runtime_resume_and_get(info->dev);
+	if (error < 0)
+		goto err;
+
+	mutex_lock(&info->lock);
+
+	erase_effect = vibra_find_effect(work_data->effect->id, &info->effect_head);
+	if (!erase_effect) {
+		dev_err(info->dev, "Effect to erase not found\n");
+		error = -EINVAL;
+		goto err_mutex;
+	}
+
+	if (erase_effect->gpio_reg != CS40L50_GPIO_MAPPING_NONE) {
+		error = regmap_write(info->regmap, erase_effect->gpio_reg,
+				     CS40L50_GPIO_DISABLE);
+		if (error)
+			goto err_mutex;
+	}
+
+	if (erase_effect->bank == WVFRM_BANK_OWT) {
+		error = info->dsp.write(info->dev, info->regmap,
+					info->dsp.delete_owt_cmd |
+					erase_effect->index);
+		if (error)
+			goto err_mutex;
+
+		list_for_each_entry(owt_effect, &info->effect_head, list)
+			if (owt_effect->bank == WVFRM_BANK_OWT &&
+			    owt_effect->index > erase_effect->index)
+				owt_effect->index--;
+	}
+
+	list_del(&erase_effect->list);
+	kfree(erase_effect);
+err_mutex:
+	mutex_unlock(&info->lock);
+
+	pm_runtime_mark_last_busy(info->dev);
+	pm_runtime_put_autosuspend(info->dev);
+err:
+	work_data->error = error;
+}
+
+static int vibra_erase(struct input_dev *dev, int effect_id)
+{
+	struct vibra_info *info = input_get_drvdata(dev);
+	struct vibra_work work_data;
+
+	work_data.info = info;
+	work_data.effect = &dev->ff->effects[effect_id];
+
+	INIT_WORK(&work_data.work, vibra_erase_worker);
+
+	/* Push to workqueue to serialize with playbacks */
+	queue_work(info->vibe_wq, &work_data.work);
+	flush_work(&work_data.work);
+
+	return work_data.error;
+}
+
+static void vibra_remove_wq(void *data)
+{
+	flush_workqueue(data);
+	destroy_workqueue(data);
+}
+
+static int cs40l50_vibra_probe(struct platform_device *pdev)
+{
+	struct cs40l50 *cs40l50 = dev_get_drvdata(pdev->dev.parent);
+	struct vibra_info *info;
+	int error;
+
+	info = devm_kzalloc(pdev->dev.parent, sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	mutex_init(&info->lock);
+
+	info->dev = cs40l50->dev;
+	info->regmap = cs40l50->regmap;
+	info->dsp = cs40l50_dsp;
+
+	info->input = devm_input_allocate_device(info->dev);
+	if (!info->input)
+		return -ENOMEM;
+	info->input->id.product = cs40l50->devid & 0xFFFF;
+	info->input->id.version = cs40l50->revid;
+	info->input->name = "cs40l50_vibra";
+
+	input_set_drvdata(info->input, info);
+	input_set_capability(info->input, EV_FF, FF_PERIODIC);
+	input_set_capability(info->input, EV_FF, FF_CUSTOM);
+
+	error = input_ff_create(info->input, FF_MAX_EFFECTS);
+	if (error) {
+		dev_err(info->dev, "Failed to create input device\n");
+		return error;
+	}
+
+	info->input->ff->upload = vibra_add;
+	info->input->ff->playback = vibra_playback;
+	info->input->ff->erase = vibra_erase;
+
+	INIT_LIST_HEAD(&info->effect_head);
+
+	info->vibe_wq = alloc_ordered_workqueue("vibe_wq", WQ_HIGHPRI);
+	if (!info->vibe_wq)
+		return -ENOMEM;
+
+	error = devm_add_action_or_reset(info->dev, vibra_remove_wq, info->vibe_wq);
+	if (error)
+		return error;
+
+	return input_register_device(info->input);
+}
+
+static const struct platform_device_id vibra_id_match[] = {
+	{ "cs40l50-vibra", },
+	{}
+};
+MODULE_DEVICE_TABLE(platform, vibra_id_match);
+
+static struct platform_driver cs40l50_vibra_driver = {
+	.probe		= cs40l50_vibra_probe,
+	.id_table	= vibra_id_match,
+	.driver		= {
+		.name	= "cs40l50-vibra",
+	},
+};
+module_platform_driver(cs40l50_vibra_driver);
+
+MODULE_DESCRIPTION("CS40L50 Advanced Haptic Driver");
+MODULE_AUTHOR("James Ogletree, Cirrus Logic Inc. <james.ogletree@cirrus.com>");
+MODULE_LICENSE("GPL");
-- 
2.25.1