Input: add support for Azoteq IQS7222A/B/C

This patch adds support for the Azoteq IQS7222A/B/C family of
capacitive touch controllers.

Signed-off-by: Jeff LaBundy <jeff@labundy.com>
Link: https://lore.kernel.org/r/20220403221659.865997-3-jeff@labundy.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

3 files changed, 2456 insertions, 0 deletions

diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig
index dd5227cf8696..a18ab7358d8f 100644
--- a/drivers/input/misc/Kconfig
+++ b/drivers/input/misc/Kconfig
@@ -762,6 +762,16 @@ config INPUT_IQS626A
 	  To compile this driver as a module, choose M here: the
 	  module will be called iqs626a.
 
+config INPUT_IQS7222
+	tristate "Azoteq IQS7222A/B/C capacitive touch controller"
+	depends on I2C
+	help
+	  Say Y to enable support for the Azoteq IQS7222A/B/C family
+	  of capacitive touch controllers.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called iqs7222.
+
 config INPUT_CMA3000
 	tristate "VTI CMA3000 Tri-axis accelerometer"
 	help
diff --git a/drivers/input/misc/Makefile b/drivers/input/misc/Makefile
index b92c53a6b5ae..28dfc444f0a9 100644
--- a/drivers/input/misc/Makefile
+++ b/drivers/input/misc/Makefile
@@ -44,6 +44,7 @@ obj-$(CONFIG_HP_SDC_RTC)		+= hp_sdc_rtc.o
 obj-$(CONFIG_INPUT_IMS_PCU)		+= ims-pcu.o
 obj-$(CONFIG_INPUT_IQS269A)		+= iqs269a.o
 obj-$(CONFIG_INPUT_IQS626A)		+= iqs626a.o
+obj-$(CONFIG_INPUT_IQS7222)		+= iqs7222.o
 obj-$(CONFIG_INPUT_KEYSPAN_REMOTE)	+= keyspan_remote.o
 obj-$(CONFIG_INPUT_KXTJ9)		+= kxtj9.o
 obj-$(CONFIG_INPUT_M68K_BEEP)		+= m68kspkr.o
diff --git a/drivers/input/misc/iqs7222.c b/drivers/input/misc/iqs7222.c
new file mode 100644
index 000000000000..d800f71043a5
--- /dev/null
+++ b/drivers/input/misc/iqs7222.c
@@ -0,0 +1,2445 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Azoteq IQS7222A/B/C Capacitive Touch Controller
+ *
+ * Copyright (C) 2022 Jeff LaBundy <jeff@labundy.com>
+ */
+
+#include <linux/bits.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/ktime.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/property.h>
+#include <linux/slab.h>
+#include <asm/unaligned.h>
+
+#define IQS7222_PROD_NUM			0x00
+#define IQS7222_PROD_NUM_A			840
+#define IQS7222_PROD_NUM_B			698
+#define IQS7222_PROD_NUM_C			863
+
+#define IQS7222_SYS_STATUS			0x10
+#define IQS7222_SYS_STATUS_RESET		BIT(3)
+#define IQS7222_SYS_STATUS_ATI_ERROR		BIT(1)
+#define IQS7222_SYS_STATUS_ATI_ACTIVE		BIT(0)
+
+#define IQS7222_CHAN_SETUP_0_REF_MODE_MASK	GENMASK(15, 14)
+#define IQS7222_CHAN_SETUP_0_REF_MODE_FOLLOW	BIT(15)
+#define IQS7222_CHAN_SETUP_0_REF_MODE_REF	BIT(14)
+#define IQS7222_CHAN_SETUP_0_CHAN_EN		BIT(8)
+
+#define IQS7222_SLDR_SETUP_0_CHAN_CNT_MASK	GENMASK(2, 0)
+#define IQS7222_SLDR_SETUP_2_RES_MASK		GENMASK(15, 8)
+#define IQS7222_SLDR_SETUP_2_RES_SHIFT		8
+#define IQS7222_SLDR_SETUP_2_TOP_SPEED_MASK	GENMASK(7, 0)
+#define IQS7222_SLDR_SETUP_3_CHAN_SEL_MASK	GENMASK(9, 0)
+
+#define IQS7222_GPIO_SETUP_0_GPIO_EN		BIT(0)
+
+#define IQS7222_SYS_SETUP			0xD0
+#define IQS7222_SYS_SETUP_INTF_MODE_MASK	GENMASK(7, 6)
+#define IQS7222_SYS_SETUP_INTF_MODE_TOUCH	BIT(7)
+#define IQS7222_SYS_SETUP_INTF_MODE_EVENT	BIT(6)
+#define IQS7222_SYS_SETUP_PWR_MODE_MASK		GENMASK(5, 4)
+#define IQS7222_SYS_SETUP_PWR_MODE_AUTO		IQS7222_SYS_SETUP_PWR_MODE_MASK
+#define IQS7222_SYS_SETUP_REDO_ATI		BIT(2)
+#define IQS7222_SYS_SETUP_ACK_RESET		BIT(0)
+
+#define IQS7222_EVENT_MASK_ATI			BIT(12)
+
+#define IQS7222_COMMS_HOLD			BIT(0)
+#define IQS7222_COMMS_ERROR			0xEEEE
+#define IQS7222_COMMS_RETRY_MS			50
+#define IQS7222_COMMS_TIMEOUT_MS		100
+#define IQS7222_RESET_TIMEOUT_MS		250
+#define IQS7222_ATI_TIMEOUT_MS			2000
+
+#define IQS7222_MAX_COLS_STAT			8
+#define IQS7222_MAX_COLS_CYCLE			3
+#define IQS7222_MAX_COLS_GLBL			3
+#define IQS7222_MAX_COLS_BTN			3
+#define IQS7222_MAX_COLS_CHAN			6
+#define IQS7222_MAX_COLS_FILT			2
+#define IQS7222_MAX_COLS_SLDR			11
+#define IQS7222_MAX_COLS_GPIO			3
+#define IQS7222_MAX_COLS_SYS			13
+
+#define IQS7222_MAX_CHAN			20
+#define IQS7222_MAX_SLDR			2
+
+#define IQS7222_NUM_RETRIES			5
+#define IQS7222_REG_OFFSET			0x100
+
+enum iqs7222_reg_key_id {
+	IQS7222_REG_KEY_NONE,
+	IQS7222_REG_KEY_PROX,
+	IQS7222_REG_KEY_TOUCH,
+	IQS7222_REG_KEY_DEBOUNCE,
+	IQS7222_REG_KEY_TAP,
+	IQS7222_REG_KEY_AXIAL,
+	IQS7222_REG_KEY_WHEEL,
+	IQS7222_REG_KEY_NO_WHEEL,
+	IQS7222_REG_KEY_RESERVED
+};
+
+enum iqs7222_reg_grp_id {
+	IQS7222_REG_GRP_STAT,
+	IQS7222_REG_GRP_CYCLE,
+	IQS7222_REG_GRP_GLBL,
+	IQS7222_REG_GRP_BTN,
+	IQS7222_REG_GRP_CHAN,
+	IQS7222_REG_GRP_FILT,
+	IQS7222_REG_GRP_SLDR,
+	IQS7222_REG_GRP_GPIO,
+	IQS7222_REG_GRP_SYS,
+	IQS7222_NUM_REG_GRPS
+};
+
+static const char * const iqs7222_reg_grp_names[] = {
+	[IQS7222_REG_GRP_CYCLE] = "cycle",
+	[IQS7222_REG_GRP_CHAN] = "channel",
+	[IQS7222_REG_GRP_SLDR] = "slider",
+	[IQS7222_REG_GRP_GPIO] = "gpio",
+};
+
+static const unsigned int iqs7222_max_cols[] = {
+	[IQS7222_REG_GRP_STAT] = IQS7222_MAX_COLS_STAT,
+	[IQS7222_REG_GRP_CYCLE] = IQS7222_MAX_COLS_CYCLE,
+	[IQS7222_REG_GRP_GLBL] = IQS7222_MAX_COLS_GLBL,
+	[IQS7222_REG_GRP_BTN] = IQS7222_MAX_COLS_BTN,
+	[IQS7222_REG_GRP_CHAN] = IQS7222_MAX_COLS_CHAN,
+	[IQS7222_REG_GRP_FILT] = IQS7222_MAX_COLS_FILT,
+	[IQS7222_REG_GRP_SLDR] = IQS7222_MAX_COLS_SLDR,
+	[IQS7222_REG_GRP_GPIO] = IQS7222_MAX_COLS_GPIO,
+	[IQS7222_REG_GRP_SYS] = IQS7222_MAX_COLS_SYS,
+};
+
+static const unsigned int iqs7222_gpio_links[] = { 2, 5, 6, };
+
+struct iqs7222_event_desc {
+	const char *name;
+	u16 mask;
+	u16 val;
+	u16 enable;
+	enum iqs7222_reg_key_id reg_key;
+};
+
+static const struct iqs7222_event_desc iqs7222_kp_events[] = {
+	{
+		.name = "event-prox",
+		.enable = BIT(0),
+		.reg_key = IQS7222_REG_KEY_PROX,
+	},
+	{
+		.name = "event-touch",
+		.enable = BIT(1),
+		.reg_key = IQS7222_REG_KEY_TOUCH,
+	},
+};
+
+static const struct iqs7222_event_desc iqs7222_sl_events[] = {
+	{ .name = "event-press", },
+	{
+		.name = "event-tap",
+		.mask = BIT(0),
+		.val = BIT(0),
+		.enable = BIT(0),
+		.reg_key = IQS7222_REG_KEY_TAP,
+	},
+	{
+		.name = "event-swipe-pos",
+		.mask = BIT(5) | BIT(1),
+		.val = BIT(1),
+		.enable = BIT(1),
+		.reg_key = IQS7222_REG_KEY_AXIAL,
+	},
+	{
+		.name = "event-swipe-neg",
+		.mask = BIT(5) | BIT(1),
+		.val = BIT(5) | BIT(1),
+		.enable = BIT(1),
+		.reg_key = IQS7222_REG_KEY_AXIAL,
+	},
+	{
+		.name = "event-flick-pos",
+		.mask = BIT(5) | BIT(2),
+		.val = BIT(2),
+		.enable = BIT(2),
+		.reg_key = IQS7222_REG_KEY_AXIAL,
+	},
+	{
+		.name = "event-flick-neg",
+		.mask = BIT(5) | BIT(2),
+		.val = BIT(5) | BIT(2),
+		.enable = BIT(2),
+		.reg_key = IQS7222_REG_KEY_AXIAL,
+	},
+};
+
+struct iqs7222_reg_grp_desc {
+	u16 base;
+	int num_row;
+	int num_col;
+};
+
+struct iqs7222_dev_desc {
+	u16 prod_num;
+	u16 fw_major;
+	u16 fw_minor;
+	u16 sldr_res;
+	u16 touch_link;
+	u16 wheel_enable;
+	int allow_offset;
+	int event_offset;
+	int comms_offset;
+	struct iqs7222_reg_grp_desc reg_grps[IQS7222_NUM_REG_GRPS];
+};
+
+static const struct iqs7222_dev_desc iqs7222_devs[] = {
+	{
+		.prod_num = IQS7222_PROD_NUM_A,
+		.fw_major = 1,
+		.fw_minor = 12,
+		.sldr_res = U8_MAX * 16,
+		.touch_link = 1768,
+		.allow_offset = 9,
+		.event_offset = 10,
+		.comms_offset = 12,
+		.reg_grps = {
+			[IQS7222_REG_GRP_STAT] = {
+				.base = IQS7222_SYS_STATUS,
+				.num_row = 1,
+				.num_col = 8,
+			},
+			[IQS7222_REG_GRP_CYCLE] = {
+				.base = 0x8000,
+				.num_row = 7,
+				.num_col = 3,
+			},
+			[IQS7222_REG_GRP_GLBL] = {
+				.base = 0x8700,
+				.num_row = 1,
+				.num_col = 3,
+			},
+			[IQS7222_REG_GRP_BTN] = {
+				.base = 0x9000,
+				.num_row = 12,
+				.num_col = 3,
+			},
+			[IQS7222_REG_GRP_CHAN] = {
+				.base = 0xA000,
+				.num_row = 12,
+				.num_col = 6,
+			},
+			[IQS7222_REG_GRP_FILT] = {
+				.base = 0xAC00,
+				.num_row = 1,
+				.num_col = 2,
+			},
+			[IQS7222_REG_GRP_SLDR] = {
+				.base = 0xB000,
+				.num_row = 2,
+				.num_col = 11,
+			},
+			[IQS7222_REG_GRP_GPIO] = {
+				.base = 0xC000,
+				.num_row = 1,
+				.num_col = 3,
+			},
+			[IQS7222_REG_GRP_SYS] = {
+				.base = IQS7222_SYS_SETUP,
+				.num_row = 1,
+				.num_col = 13,
+			},
+		},
+	},
+	{
+		.prod_num = IQS7222_PROD_NUM_B,
+		.fw_major = 1,
+		.fw_minor = 43,
+		.event_offset = 10,
+		.comms_offset = 11,
+		.reg_grps = {
+			[IQS7222_REG_GRP_STAT] = {
+				.base = IQS7222_SYS_STATUS,
+				.num_row = 1,
+				.num_col = 6,
+			},
+			[IQS7222_REG_GRP_CYCLE] = {
+				.base = 0x8000,
+				.num_row = 10,
+				.num_col = 2,
+			},
+			[IQS7222_REG_GRP_GLBL] = {
+				.base = 0x8A00,
+				.num_row = 1,
+				.num_col = 3,
+			},
+			[IQS7222_REG_GRP_BTN] = {
+				.base = 0x9000,
+				.num_row = 20,
+				.num_col = 2,
+			},
+			[IQS7222_REG_GRP_CHAN] = {
+				.base = 0xB000,
+				.num_row = 20,
+				.num_col = 4,
+			},
+			[IQS7222_REG_GRP_FILT] = {
+				.base = 0xC400,
+				.num_row = 1,
+				.num_col = 2,
+			},
+			[IQS7222_REG_GRP_SYS] = {
+				.base = IQS7222_SYS_SETUP,
+				.num_row = 1,
+				.num_col = 13,
+			},
+		},
+	},
+	{
+		.prod_num = IQS7222_PROD_NUM_B,
+		.fw_major = 1,
+		.fw_minor = 27,
+		.reg_grps = {
+			[IQS7222_REG_GRP_STAT] = {
+				.base = IQS7222_SYS_STATUS,
+				.num_row = 1,
+				.num_col = 6,
+			},
+			[IQS7222_REG_GRP_CYCLE] = {
+				.base = 0x8000,
+				.num_row = 10,
+				.num_col = 2,
+			},
+			[IQS7222_REG_GRP_GLBL] = {
+				.base = 0x8A00,
+				.num_row = 1,
+				.num_col = 3,
+			},
+			[IQS7222_REG_GRP_BTN] = {
+				.base = 0x9000,
+				.num_row = 20,
+				.num_col = 2,
+			},
+			[IQS7222_REG_GRP_CHAN] = {
+				.base = 0xB000,
+				.num_row = 20,
+				.num_col = 4,
+			},
+			[IQS7222_REG_GRP_FILT] = {
+				.base = 0xC400,
+				.num_row = 1,
+				.num_col = 2,
+			},
+			[IQS7222_REG_GRP_SYS] = {
+				.base = IQS7222_SYS_SETUP,
+				.num_row = 1,
+				.num_col = 10,
+			},
+		},
+	},
+	{
+		.prod_num = IQS7222_PROD_NUM_C,
+		.fw_major = 2,
+		.fw_minor = 6,
+		.sldr_res = U16_MAX,
+		.touch_link = 1686,
+		.wheel_enable = BIT(3),
+		.event_offset = 9,
+		.comms_offset = 10,
+		.reg_grps = {
+			[IQS7222_REG_GRP_STAT] = {
+				.base = IQS7222_SYS_STATUS,
+				.num_row = 1,
+				.num_col = 6,
+			},
+			[IQS7222_REG_GRP_CYCLE] = {
+				.base = 0x8000,
+				.num_row = 5,
+				.num_col = 3,
+			},
+			[IQS7222_REG_GRP_GLBL] = {
+				.base = 0x8500,
+				.num_row = 1,
+				.num_col = 3,
+			},
+			[IQS7222_REG_GRP_BTN] = {
+				.base = 0x9000,
+				.num_row = 10,
+				.num_col = 3,
+			},
+			[IQS7222_REG_GRP_CHAN] = {
+				.base = 0xA000,
+				.num_row = 10,
+				.num_col = 6,
+			},
+			[IQS7222_REG_GRP_FILT] = {
+				.base = 0xAA00,
+				.num_row = 1,
+				.num_col = 2,
+			},
+			[IQS7222_REG_GRP_SLDR] = {
+				.base = 0xB000,
+				.num_row = 2,
+				.num_col = 10,
+			},
+			[IQS7222_REG_GRP_GPIO] = {
+				.base = 0xC000,
+				.num_row = 3,
+				.num_col = 3,
+			},
+			[IQS7222_REG_GRP_SYS] = {
+				.base = IQS7222_SYS_SETUP,
+				.num_row = 1,
+				.num_col = 12,
+			},
+		},
+	},
+	{
+		.prod_num = IQS7222_PROD_NUM_C,
+		.fw_major = 1,
+		.fw_minor = 13,
+		.sldr_res = U16_MAX,
+		.touch_link = 1674,
+		.wheel_enable = BIT(3),
+		.event_offset = 9,
+		.comms_offset = 10,
+		.reg_grps = {
+			[IQS7222_REG_GRP_STAT] = {
+				.base = IQS7222_SYS_STATUS,
+				.num_row = 1,
+				.num_col = 6,
+			},
+			[IQS7222_REG_GRP_CYCLE] = {
+				.base = 0x8000,
+				.num_row = 5,
+				.num_col = 3,
+			},
+			[IQS7222_REG_GRP_GLBL] = {
+				.base = 0x8500,
+				.num_row = 1,
+				.num_col = 3,
+			},
+			[IQS7222_REG_GRP_BTN] = {
+				.base = 0x9000,
+				.num_row = 10,
+				.num_col = 3,
+			},
+			[IQS7222_REG_GRP_CHAN] = {
+				.base = 0xA000,
+				.num_row = 10,
+				.num_col = 6,
+			},
+			[IQS7222_REG_GRP_FILT] = {
+				.base = 0xAA00,
+				.num_row = 1,
+				.num_col = 2,
+			},
+			[IQS7222_REG_GRP_SLDR] = {
+				.base = 0xB000,
+				.num_row = 2,
+				.num_col = 10,
+			},
+			[IQS7222_REG_GRP_GPIO] = {
+				.base = 0xC000,
+				.num_row = 1,
+				.num_col = 3,
+			},
+			[IQS7222_REG_GRP_SYS] = {
+				.base = IQS7222_SYS_SETUP,
+				.num_row = 1,
+				.num_col = 11,
+			},
+		},
+	},
+};
+
+struct iqs7222_prop_desc {
+	const char *name;
+	enum iqs7222_reg_grp_id reg_grp;
+	enum iqs7222_reg_key_id reg_key;
+	int reg_offset;
+	int reg_shift;
+	int reg_width;
+	int val_pitch;
+	int val_min;
+	int val_max;
+	bool invert;
+	const char *label;
+};
+
+static const struct iqs7222_prop_desc iqs7222_props[] = {
+	{
+		.name = "azoteq,conv-period",
+		.reg_grp = IQS7222_REG_GRP_CYCLE,
+		.reg_offset = 0,
+		.reg_shift = 8,
+		.reg_width = 8,
+		.label = "conversion period",
+	},
+	{
+		.name = "azoteq,conv-frac",
+		.reg_grp = IQS7222_REG_GRP_CYCLE,
+		.reg_offset = 0,
+		.reg_shift = 0,
+		.reg_width = 8,
+		.label = "conversion frequency fractional divider",
+	},
+	{
+		.name = "azoteq,rx-float-inactive",
+		.reg_grp = IQS7222_REG_GRP_CYCLE,
+		.reg_offset = 1,
+		.reg_shift = 6,
+		.reg_width = 1,
+		.invert = true,
+	},
+	{
+		.name = "azoteq,dead-time-enable",
+		.reg_grp = IQS7222_REG_GRP_CYCLE,
+		.reg_offset = 1,
+		.reg_shift = 5,
+		.reg_width = 1,
+	},
+	{
+		.name = "azoteq,tx-freq-fosc",
+		.reg_grp = IQS7222_REG_GRP_CYCLE,
+		.reg_offset = 1,
+		.reg_shift = 4,
+		.reg_width = 1,
+	},
+	{
+		.name = "azoteq,vbias-enable",
+		.reg_grp = IQS7222_REG_GRP_CYCLE,
+		.reg_offset = 1,
+		.reg_shift = 3,
+		.reg_width = 1,
+	},
+	{
+		.name = "azoteq,sense-mode",
+		.reg_grp = IQS7222_REG_GRP_CYCLE,
+		.reg_offset = 1,
+		.reg_shift = 0,
+		.reg_width = 3,
+		.val_max = 3,
+		.label = "sensing mode",
+	},
+	{
+		.name = "azoteq,iref-enable",
+		.reg_grp = IQS7222_REG_GRP_CYCLE,
+		.reg_offset = 2,
+		.reg_shift = 10,
+		.reg_width = 1,
+	},
+	{
+		.name = "azoteq,iref-level",
+		.reg_grp = IQS7222_REG_GRP_CYCLE,
+		.reg_offset = 2,
+		.reg_shift = 4,
+		.reg_width = 4,
+		.label = "current reference level",
+	},
+	{
+		.name = "azoteq,iref-trim",
+		.reg_grp = IQS7222_REG_GRP_CYCLE,
+		.reg_offset = 2,
+		.reg_shift = 0,
+		.reg_width = 4,
+		.label = "current reference trim",
+	},
+	{
+		.name = "azoteq,rf-filt-enable",
+		.reg_grp = IQS7222_REG_GRP_GLBL,
+		.reg_offset = 0,
+		.reg_shift = 15,
+		.reg_width = 1,
+	},
+	{
+		.name = "azoteq,max-counts",
+		.reg_grp = IQS7222_REG_GRP_GLBL,
+		.reg_offset = 0,
+		.reg_shift = 13,
+		.reg_width = 2,
+		.label = "maximum counts",
+	},
+	{
+		.name = "azoteq,auto-mode",
+		.reg_grp = IQS7222_REG_GRP_GLBL,
+		.reg_offset = 0,
+		.reg_shift = 2,
+		.reg_width = 2,
+		.label = "number of conversions",
+	},
+	{
+		.name = "azoteq,ati-frac-div-fine",
+		.reg_grp = IQS7222_REG_GRP_GLBL,
+		.reg_offset = 1,
+		.reg_shift = 9,
+		.reg_width = 5,
+		.label = "ATI fine fractional divider",
+	},
+	{
+		.name = "azoteq,ati-frac-div-coarse",
+		.reg_grp = IQS7222_REG_GRP_GLBL,
+		.reg_offset = 1,
+		.reg_shift = 0,
+		.reg_width = 5,
+		.label = "ATI coarse fractional divider",
+	},
+	{
+		.name = "azoteq,ati-comp-select",
+		.reg_grp = IQS7222_REG_GRP_GLBL,
+		.reg_offset = 2,
+		.reg_shift = 0,
+		.reg_width = 10,
+		.label = "ATI compensation selection",
+	},
+	{
+		.name = "azoteq,ati-band",
+		.reg_grp = IQS7222_REG_GRP_CHAN,
+		.reg_offset = 0,
+		.reg_shift = 12,
+		.reg_width = 2,
+		.label = "ATI band",
+	},
+	{
+		.name = "azoteq,global-halt",
+		.reg_grp = IQS7222_REG_GRP_CHAN,
+		.reg_offset = 0,
+		.reg_shift = 11,
+		.reg_width = 1,
+	},
+	{
+		.name = "azoteq,invert-enable",
+		.reg_grp = IQS7222_REG_GRP_CHAN,
+		.reg_offset = 0,
+		.reg_shift = 10,
+		.reg_width = 1,
+	},
+	{
+		.name = "azoteq,dual-direction",
+		.reg_grp = IQS7222_REG_GRP_CHAN,
+		.reg_offset = 0,
+		.reg_shift = 9,
+		.reg_width = 1,
+	},
+	{
+		.name = "azoteq,samp-cap-double",
+		.reg_grp = IQS7222_REG_GRP_CHAN,
+		.reg_offset = 0,
+		.reg_shift = 3,
+		.reg_width = 1,
+	},
+	{
+		.name = "azoteq,vref-half",
+		.reg_grp = IQS7222_REG_GRP_CHAN,
+		.reg_offset = 0,
+		.reg_shift = 2,
+		.reg_width = 1,
+	},
+	{
+		.name = "azoteq,proj-bias",
+		.reg_grp = IQS7222_REG_GRP_CHAN,
+		.reg_offset = 0,
+		.reg_shift = 0,
+		.reg_width = 2,
+		.label = "projected bias current",
+	},
+	{
+		.name = "azoteq,ati-target",
+		.reg_grp = IQS7222_REG_GRP_CHAN,
+		.reg_offset = 1,
+		.reg_shift = 8,
+		.reg_width = 8,
+		.val_pitch = 8,
+		.label = "ATI target",
+	},
+	{
+		.name = "azoteq,ati-base",
+		.reg_grp = IQS7222_REG_GRP_CHAN,
+		.reg_offset = 1,
+		.reg_shift = 3,
+		.reg_width = 5,
+		.val_pitch = 16,
+		.label = "ATI base",
+	},
+	{
+		.name = "azoteq,ati-mode",
+		.reg_grp = IQS7222_REG_GRP_CHAN,
+		.reg_offset = 1,
+		.reg_shift = 0,
+		.reg_width = 3,
+		.val_max = 5,
+		.label = "ATI mode",
+	},
+	{
+		.name = "azoteq,ati-frac-div-fine",
+		.reg_grp = IQS7222_REG_GRP_CHAN,
+		.reg_offset = 2,
+		.reg_shift = 9,
+		.reg_width = 5,
+		.label = "ATI fine fractional divider",
+	},
+	{
+		.name = "azoteq,ati-frac-mult-coarse",
+		.reg_grp = IQS7222_REG_GRP_CHAN,
+		.reg_offset = 2,
+		.reg_shift = 5,
+		.reg_width = 4,
+		.label = "ATI coarse fractional multiplier",
+	},
+	{
+		.name = "azoteq,ati-frac-div-coarse",
+		.reg_grp = IQS7222_REG_GRP_CHAN,
+		.reg_offset = 2,
+		.reg_shift = 0,
+		.reg_width = 5,
+		.label = "ATI coarse fractional divider",
+	},
+	{
+		.name = "azoteq,ati-comp-div",
+		.reg_grp = IQS7222_REG_GRP_CHAN,
+		.reg_offset = 3,
+		.reg_shift = 11,
+		.reg_width = 5,
+		.label = "ATI compensation divider",
+	},
+	{
+		.name = "azoteq,ati-comp-select",
+		.reg_grp = IQS7222_REG_GRP_CHAN,
+		.reg_offset = 3,
+		.reg_shift = 0,
+		.reg_width = 10,
+		.label = "ATI compensation selection",
+	},
+	{
+		.name = "azoteq,debounce-exit",
+		.reg_grp = IQS7222_REG_GRP_BTN,
+		.reg_key = IQS7222_REG_KEY_DEBOUNCE,
+		.reg_offset = 0,
+		.reg_shift = 12,
+		.reg_width = 4,
+		.label = "debounce exit factor",
+	},
+	{
+		.name = "azoteq,debounce-enter",
+		.reg_grp = IQS7222_REG_GRP_BTN,
+		.reg_key = IQS7222_REG_KEY_DEBOUNCE,
+		.reg_offset = 0,
+		.reg_shift = 8,
+		.reg_width = 4,
+		.label = "debounce entrance factor",
+	},
+	{
+		.name = "azoteq,thresh",
+		.reg_grp = IQS7222_REG_GRP_BTN,
+		.reg_key = IQS7222_REG_KEY_PROX,
+		.reg_offset = 0,
+		.reg_shift = 0,
+		.reg_width = 8,
+		.val_max = 127,
+		.label = "threshold",
+	},
+	{
+		.name = "azoteq,thresh",
+		.reg_grp = IQS7222_REG_GRP_BTN,
+		.reg_key = IQS7222_REG_KEY_TOUCH,
+		.reg_offset = 1,
+		.reg_shift = 0,
+		.reg_width = 8,
+		.label = "threshold",
+	},
+	{
+		.name = "azoteq,hyst",
+		.reg_grp = IQS7222_REG_GRP_BTN,
+		.reg_key = IQS7222_REG_KEY_TOUCH,
+		.reg_offset = 1,
+		.reg_shift = 8,
+		.reg_width = 8,
+		.label = "hysteresis",
+	},
+	{
+		.name = "azoteq,lta-beta-lp",
+		.reg_grp = IQS7222_REG_GRP_FILT,
+		.reg_offset = 0,
+		.reg_shift = 12,
+		.reg_width = 4,
+		.label = "low-power mode long-term average beta",
+	},
+	{
+		.name = "azoteq,lta-beta-np",
+		.reg_grp = IQS7222_REG_GRP_FILT,
+		.reg_offset = 0,
+		.reg_shift = 8,
+		.reg_width = 4,
+		.label = "normal-power mode long-term average beta",
+	},
+	{
+		.name = "azoteq,counts-beta-lp",
+		.reg_grp = IQS7222_REG_GRP_FILT,
+		.reg_offset = 0,
+		.reg_shift = 4,
+		.reg_width = 4,
+		.label = "low-power mode counts beta",
+	},
+	{
+		.name = "azoteq,counts-beta-np",
+		.reg_grp = IQS7222_REG_GRP_FILT,
+		.reg_offset = 0,
+		.reg_shift = 0,
+		.reg_width = 4,
+		.label = "normal-power mode counts beta",
+	},
+	{
+		.name = "azoteq,lta-fast-beta-lp",
+		.reg_grp = IQS7222_REG_GRP_FILT,
+		.reg_offset = 1,
+		.reg_shift = 4,
+		.reg_width = 4,
+		.label = "low-power mode long-term average fast beta",
+	},
+	{
+		.name = "azoteq,lta-fast-beta-np",
+		.reg_grp = IQS7222_REG_GRP_FILT,
+		.reg_offset = 1,
+		.reg_shift = 0,
+		.reg_width = 4,
+		.label = "normal-power mode long-term average fast beta",
+	},
+	{
+		.name = "azoteq,lower-cal",
+		.reg_grp = IQS7222_REG_GRP_SLDR,
+		.reg_offset = 0,
+		.reg_shift = 8,
+		.reg_width = 8,
+		.label = "lower calibration",
+	},
+	{
+		.name = "azoteq,static-beta",
+		.reg_grp = IQS7222_REG_GRP_SLDR,
+		.reg_key = IQS7222_REG_KEY_NO_WHEEL,
+		.reg_offset = 0,
+		.reg_shift = 6,
+		.reg_width = 1,
+	},
+	{
+		.name = "azoteq,bottom-beta",
+		.reg_grp = IQS7222_REG_GRP_SLDR,
+		.reg_key = IQS7222_REG_KEY_NO_WHEEL,
+		.reg_offset = 0,
+		.reg_shift = 3,
+		.reg_width = 3,
+		.label = "bottom beta",
+	},
+	{
+		.name = "azoteq,static-beta",
+		.reg_grp = IQS7222_REG_GRP_SLDR,
+		.reg_key = IQS7222_REG_KEY_WHEEL,
+		.reg_offset = 0,
+		.reg_shift = 7,
+		.reg_width = 1,
+	},
+	{
+		.name = "azoteq,bottom-beta",
+		.reg_grp = IQS7222_REG_GRP_SLDR,
+		.reg_key = IQS7222_REG_KEY_WHEEL,
+		.reg_offset = 0,
+		.reg_shift = 4,
+		.reg_width = 3,
+		.label = "bottom beta",
+	},
+	{
+		.name = "azoteq,bottom-speed",
+		.reg_grp = IQS7222_REG_GRP_SLDR,
+		.reg_offset = 1,
+		.reg_shift = 8,
+		.reg_width = 8,
+		.label = "bottom speed",
+	},
+	{
+		.name = "azoteq,upper-cal",
+		.reg_grp = IQS7222_REG_GRP_SLDR,
+		.reg_offset = 1,
+		.reg_shift = 0,
+		.reg_width = 8,
+		.label = "upper calibration",
+	},
+	{
+		.name = "azoteq,gesture-max-ms",
+		.reg_grp = IQS7222_REG_GRP_SLDR,
+		.reg_key = IQS7222_REG_KEY_TAP,
+		.reg_offset = 9,
+		.reg_shift = 8,
+		.reg_width = 8,
+		.val_pitch = 4,
+		.label = "maximum gesture time",
+	},
+	{
+		.name = "azoteq,gesture-min-ms",
+		.reg_grp = IQS7222_REG_GRP_SLDR,
+		.reg_key = IQS7222_REG_KEY_TAP,
+		.reg_offset = 9,
+		.reg_shift = 3,
+		.reg_width = 5,
+		.val_pitch = 4,
+		.label = "minimum gesture time",
+	},
+	{
+		.name = "azoteq,gesture-dist",
+		.reg_grp = IQS7222_REG_GRP_SLDR,
+		.reg_key = IQS7222_REG_KEY_AXIAL,
+		.reg_offset = 10,
+		.reg_shift = 8,
+		.reg_width = 8,
+		.val_pitch = 16,
+		.label = "gesture distance",
+	},
+	{
+		.name = "azoteq,gesture-max-ms",
+		.reg_grp = IQS7222_REG_GRP_SLDR,
+		.reg_key = IQS7222_REG_KEY_AXIAL,
+		.reg_offset = 10,
+		.reg_shift = 0,
+		.reg_width = 8,
+		.val_pitch = 4,
+		.label = "maximum gesture time",
+	},
+	{
+		.name = "drive-open-drain",
+		.reg_grp = IQS7222_REG_GRP_GPIO,
+		.reg_offset = 0,
+		.reg_shift = 1,
+		.reg_width = 1,
+	},
+	{
+		.name = "azoteq,timeout-ati-ms",
+		.reg_grp = IQS7222_REG_GRP_SYS,
+		.reg_offset = 1,
+		.reg_shift = 0,
+		.reg_width = 16,
+		.val_pitch = 500,
+		.label = "ATI error timeout",
+	},
+	{
+		.name = "azoteq,rate-ati-ms",
+		.reg_grp = IQS7222_REG_GRP_SYS,
+		.reg_offset = 2,
+		.reg_shift = 0,
+		.reg_width = 16,
+		.label = "ATI report rate",
+	},
+	{
+		.name = "azoteq,timeout-np-ms",
+		.reg_grp = IQS7222_REG_GRP_SYS,
+		.reg_offset = 3,
+		.reg_shift = 0,
+		.reg_width = 16,
+		.label = "normal-power mode timeout",
+	},
+	{
+		.name = "azoteq,rate-np-ms",
+		.reg_grp = IQS7222_REG_GRP_SYS,
+		.reg_offset = 4,
+		.reg_shift = 0,
+		.reg_width = 16,
+		.val_max = 3000,
+		.label = "normal-power mode report rate",
+	},
+	{
+		.name = "azoteq,timeout-lp-ms",
+		.reg_grp = IQS7222_REG_GRP_SYS,
+		.reg_offset = 5,
+		.reg_shift = 0,
+		.reg_width = 16,
+		.label = "low-power mode timeout",
+	},
+	{
+		.name = "azoteq,rate-lp-ms",
+		.reg_grp = IQS7222_REG_GRP_SYS,
+		.reg_offset = 6,
+		.reg_shift = 0,
+		.reg_width = 16,
+		.val_max = 3000,
+		.label = "low-power mode report rate",
+	},
+	{
+		.name = "azoteq,timeout-ulp-ms",
+		.reg_grp = IQS7222_REG_GRP_SYS,
+		.reg_offset = 7,
+		.reg_shift = 0,
+		.reg_width = 16,
+		.label = "ultra-low-power mode timeout",
+	},
+	{
+		.name = "azoteq,rate-ulp-ms",
+		.reg_grp = IQS7222_REG_GRP_SYS,
+		.reg_offset = 8,
+		.reg_shift = 0,
+		.reg_width = 16,
+		.val_max = 3000,
+		.label = "ultra-low-power mode report rate",
+	},
+};
+
+struct iqs7222_private {
+	const struct iqs7222_dev_desc *dev_desc;
+	struct gpio_desc *reset_gpio;
+	struct gpio_desc *irq_gpio;
+	struct i2c_client *client;
+	struct input_dev *keypad;
+	unsigned int kp_type[IQS7222_MAX_CHAN][ARRAY_SIZE(iqs7222_kp_events)];
+	unsigned int kp_code[IQS7222_MAX_CHAN][ARRAY_SIZE(iqs7222_kp_events)];
+	unsigned int sl_code[IQS7222_MAX_SLDR][ARRAY_SIZE(iqs7222_sl_events)];
+	unsigned int sl_axis[IQS7222_MAX_SLDR];
+	u16 cycle_setup[IQS7222_MAX_CHAN / 2][IQS7222_MAX_COLS_CYCLE];
+	u16 glbl_setup[IQS7222_MAX_COLS_GLBL];
+	u16 btn_setup[IQS7222_MAX_CHAN][IQS7222_MAX_COLS_BTN];
+	u16 chan_setup[IQS7222_MAX_CHAN][IQS7222_MAX_COLS_CHAN];
+	u16 filt_setup[IQS7222_MAX_COLS_FILT];
+	u16 sldr_setup[IQS7222_MAX_SLDR][IQS7222_MAX_COLS_SLDR];
+	u16 gpio_setup[ARRAY_SIZE(iqs7222_gpio_links)][IQS7222_MAX_COLS_GPIO];
+	u16 sys_setup[IQS7222_MAX_COLS_SYS];
+};
+
+static u16 *iqs7222_setup(struct iqs7222_private *iqs7222,
+			  enum iqs7222_reg_grp_id reg_grp, int row)
+{
+	switch (reg_grp) {
+	case IQS7222_REG_GRP_CYCLE:
+		return iqs7222->cycle_setup[row];
+
+	case IQS7222_REG_GRP_GLBL:
+		return iqs7222->glbl_setup;
+
+	case IQS7222_REG_GRP_BTN:
+		return iqs7222->btn_setup[row];
+
+	case IQS7222_REG_GRP_CHAN:
+		return iqs7222->chan_setup[row];
+
+	case IQS7222_REG_GRP_FILT:
+		return iqs7222->filt_setup;
+
+	case IQS7222_REG_GRP_SLDR:
+		return iqs7222->sldr_setup[row];
+
+	case IQS7222_REG_GRP_GPIO:
+		return iqs7222->gpio_setup[row];
+
+	case IQS7222_REG_GRP_SYS:
+		return iqs7222->sys_setup;
+
+	default:
+		return NULL;
+	}
+}
+
+static int iqs7222_irq_poll(struct iqs7222_private *iqs7222, u16 timeout_ms)
+{
+	ktime_t irq_timeout = ktime_add_ms(ktime_get(), timeout_ms);
+	int ret;
+
+	do {
+		usleep_range(1000, 1100);
+
+		ret = gpiod_get_value_cansleep(iqs7222->irq_gpio);
+		if (ret < 0)
+			return ret;
+		else if (ret > 0)
+			return 0;
+	} while (ktime_compare(ktime_get(), irq_timeout) < 0);
+
+	return -EBUSY;
+}
+
+static int iqs7222_hard_reset(struct iqs7222_private *iqs7222)
+{
+	struct i2c_client *client = iqs7222->client;
+	int error;
+
+	if (!iqs7222->reset_gpio)
+		return 0;
+
+	gpiod_set_value_cansleep(iqs7222->reset_gpio, 1);
+	usleep_range(1000, 1100);
+
+	gpiod_set_value_cansleep(iqs7222->reset_gpio, 0);
+
+	error = iqs7222_irq_poll(iqs7222, IQS7222_RESET_TIMEOUT_MS);
+	if (error)
+		dev_err(&client->dev, "Failed to reset device: %d\n", error);
+
+	return error;
+}
+
+static int iqs7222_force_comms(struct iqs7222_private *iqs7222)
+{
+	u8 msg_buf[] = { 0xFF, 0x00, };
+	int ret;
+
+	/*
+	 * The device cannot communicate until it asserts its interrupt (RDY)
+	 * pin. Attempts to do so while RDY is deasserted return an ACK; how-
+	 * ever all write data is ignored, and all read data returns 0xEE.
+	 *
+	 * Unsolicited communication must be preceded by a special force com-
+	 * munication command, after which the device eventually asserts its
+	 * RDY pin and agrees to communicate.
+	 *
+	 * Regardless of whether communication is forced or the result of an
+	 * interrupt, the device automatically deasserts its RDY pin once it
+	 * detects an I2C stop condition, or a timeout expires.
+	 */
+	ret = gpiod_get_value_cansleep(iqs7222->irq_gpio);
+	if (ret < 0)
+		return ret;
+	else if (ret > 0)
+		return 0;
+
+	ret = i2c_master_send(iqs7222->client, msg_buf, sizeof(msg_buf));
+	if (ret < (int)sizeof(msg_buf)) {
+		if (ret >= 0)
+			ret = -EIO;
+
+		/*
+		 * The datasheet states that the host must wait to retry any
+		 * failed attempt to communicate over I2C.
+		 */
+		msleep(IQS7222_COMMS_RETRY_MS);
+		return ret;
+	}
+
+	return iqs7222_irq_poll(iqs7222, IQS7222_COMMS_TIMEOUT_MS);
+}
+
+static int iqs7222_read_burst(struct iqs7222_private *iqs7222,
+			      u16 reg, void *val, u16 num_val)
+{
+	u8 reg_buf[sizeof(__be16)];
+	int ret, i;
+	struct i2c_client *client = iqs7222->client;
+	struct i2c_msg msg[] = {
+		{
+			.addr = client->addr,
+			.flags = 0,
+			.len = reg > U8_MAX ? sizeof(reg) : sizeof(u8),
+			.buf = reg_buf,
+		},
+		{
+			.addr = client->addr,
+			.flags = I2C_M_RD,
+			.len = num_val * sizeof(__le16),
+			.buf = (u8 *)val,
+		},
+	};
+
+	if (reg > U8_MAX)
+		put_unaligned_be16(reg, reg_buf);
+	else
+		*reg_buf = (u8)reg;
+
+	/*
+	 * The following loop protects against an edge case in which the RDY
+	 * pin is automatically deasserted just as the read is initiated. In
+	 * that case, the read must be retried using forced communication.
+	 */
+	for (i = 0; i < IQS7222_NUM_RETRIES; i++) {
+		ret = iqs7222_force_comms(iqs7222);
+		if (ret < 0)
+			continue;
+
+		ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
+		if (ret < (int)ARRAY_SIZE(msg)) {
+			if (ret >= 0)
+				ret = -EIO;
+
+			msleep(IQS7222_COMMS_RETRY_MS);
+			continue;
+		}
+
+		if (get_unaligned_le16(msg[1].buf) == IQS7222_COMMS_ERROR) {
+			ret = -ENODATA;
+			continue;
+		}
+
+		ret = 0;
+		break;
+	}
+
+	/*
+	 * The following delay ensures the device has deasserted the RDY pin
+	 * following the I2C stop condition.
+	 */
+	usleep_range(50, 100);
+
+	if (ret < 0)
+		dev_err(&client->dev,