Input: add support for Azoteq IQS550/572/525
authorJeff LaBundy <jeff@labundy.com>
Tue, 30 Apr 2019 07:16:11 +0000 (00:16 -0700)
committerDmitry Torokhov <dmitry.torokhov@gmail.com>
Tue, 30 Apr 2019 07:38:51 +0000 (00:38 -0700)
This patch adds support for the Azoteq IQS550/572/525 family of
trackpad/touchscreen controllers.

The driver has been tested with an IQS550EV02 evaluation board. A
demonstration of the driver's capabilities is available here:

https://youtu.be/sRNNx4XZBts

Signed-off-by: Jeff LaBundy <jeff@labundy.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Documentation/devicetree/bindings/input/touchscreen/iqs5xx.txt [new file with mode: 0644]
Documentation/devicetree/bindings/vendor-prefixes.txt
drivers/input/touchscreen/Kconfig
drivers/input/touchscreen/Makefile
drivers/input/touchscreen/iqs5xx.c [new file with mode: 0644]

diff --git a/Documentation/devicetree/bindings/input/touchscreen/iqs5xx.txt b/Documentation/devicetree/bindings/input/touchscreen/iqs5xx.txt
new file mode 100644 (file)
index 0000000..efa0820
--- /dev/null
@@ -0,0 +1,80 @@
+Azoteq IQS550/572/525 Trackpad/Touchscreen Controller
+
+Required properties:
+
+- compatible                   : Must be equal to one of the following:
+                                 "azoteq,iqs550"
+                                 "azoteq,iqs572"
+                                 "azoteq,iqs525"
+
+- reg                          : I2C slave address for the device.
+
+- interrupts                   : GPIO to which the device's active-high RDY
+                                 output is connected (see [0]).
+
+- reset-gpios                  : GPIO to which the device's active-low NRST
+                                 input is connected (see [1]).
+
+Optional properties:
+
+- touchscreen-min-x            : See [2].
+
+- touchscreen-min-y            : See [2].
+
+- touchscreen-size-x           : See [2]. If this property is omitted, the
+                                 maximum x-coordinate is specified by the
+                                 device's "X Resolution" register.
+
+- touchscreen-size-y           : See [2]. If this property is omitted, the
+                                 maximum y-coordinate is specified by the
+                                 device's "Y Resolution" register.
+
+- touchscreen-max-pressure     : See [2]. Pressure is expressed as the sum of
+                                 the deltas across all channels impacted by a
+                                 touch event. A channel's delta is calculated
+                                 as its count value minus a reference, where
+                                 the count value is inversely proportional to
+                                 the channel's capacitance.
+
+- touchscreen-fuzz-x           : See [2].
+
+- touchscreen-fuzz-y           : See [2].
+
+- touchscreen-fuzz-pressure    : See [2].
+
+- touchscreen-inverted-x       : See [2]. Inversion is applied relative to that
+                                 which may already be specified by the device's
+                                 FLIP_X and FLIP_Y register fields.
+
+- touchscreen-inverted-y       : See [2]. Inversion is applied relative to that
+                                 which may already be specified by the device's
+                                 FLIP_X and FLIP_Y register fields.
+
+- touchscreen-swapped-x-y      : See [2]. Swapping is applied relative to that
+                                 which may already be specified by the device's
+                                 SWITCH_XY_AXIS register field.
+
+[0]: Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
+[1]: Documentation/devicetree/bindings/gpio/gpio.txt
+[2]: Documentation/devicetree/bindings/input/touchscreen/touchscreen.txt
+
+Example:
+
+       &i2c1 {
+               /* ... */
+
+               touchscreen@74 {
+                       compatible = "azoteq,iqs550";
+                       reg = <0x74>;
+                       interrupt-parent = <&gpio>;
+                       interrupts = <17 4>;
+                       reset-gpios = <&gpio 27 1>;
+
+                       touchscreen-size-x = <640>;
+                       touchscreen-size-y = <480>;
+
+                       touchscreen-max-pressure = <16000>;
+               };
+
+               /* ... */
+       };
index 4b1a2a8fcc16185cd5fae518e0e2fb953becac6f..51f99549161edf72f6a58bbece2ae190db0aa7d2 100644 (file)
@@ -53,6 +53,7 @@ avic  Shanghai AVIC Optoelectronics Co., Ltd.
 avnet  Avnet, Inc.
 axentia        Axentia Technologies AB
 axis   Axis Communications AB
 avnet  Avnet, Inc.
 axentia        Axentia Technologies AB
 axis   Axis Communications AB
+azoteq Azoteq (Pty) Ltd
 bananapi BIPAI KEJI LIMITED
 bhf    Beckhoff Automation GmbH & Co. KG
 bitmain        Bitmain Technologies
 bananapi BIPAI KEJI LIMITED
 bhf    Beckhoff Automation GmbH & Co. KG
 bitmain        Bitmain Technologies
index 6c16aaeb419122bd39ce785ca959f1aa2af9a161..d8337ed50af40043ba839ef304c4bfc976f87b71 100644 (file)
@@ -1311,4 +1311,14 @@ config TOUCHSCREEN_ROHM_BU21023
          To compile this driver as a module, choose M here: the
          module will be called bu21023_ts.
 
          To compile this driver as a module, choose M here: the
          module will be called bu21023_ts.
 
+config TOUCHSCREEN_IQS5XX
+       tristate "Azoteq IQS550/572/525 trackpad/touchscreen controller"
+       depends on I2C
+       help
+         Say Y to enable support for the Azoteq IQS550/572/525
+         family of trackpad/touchscreen controllers.
+
+         To compile this driver as a module, choose M here: the
+         module will be called iqs5xx.
+
 endif
 endif
index fcc7605fba8dba99e88d6b319b0ab94bd538f734..084a596a0c8bda9e064498c1c736d9868814bfff 100644 (file)
@@ -110,3 +110,4 @@ obj-$(CONFIG_TOUCHSCREEN_ZFORCE)    += zforce_ts.o
 obj-$(CONFIG_TOUCHSCREEN_COLIBRI_VF50) += colibri-vf50-ts.o
 obj-$(CONFIG_TOUCHSCREEN_ROHM_BU21023) += rohm_bu21023.o
 obj-$(CONFIG_TOUCHSCREEN_RASPBERRYPI_FW)       += raspberrypi-ts.o
 obj-$(CONFIG_TOUCHSCREEN_COLIBRI_VF50) += colibri-vf50-ts.o
 obj-$(CONFIG_TOUCHSCREEN_ROHM_BU21023) += rohm_bu21023.o
 obj-$(CONFIG_TOUCHSCREEN_RASPBERRYPI_FW)       += raspberrypi-ts.o
+obj-$(CONFIG_TOUCHSCREEN_IQS5XX)       += iqs5xx.o
diff --git a/drivers/input/touchscreen/iqs5xx.c b/drivers/input/touchscreen/iqs5xx.c
new file mode 100644 (file)
index 0000000..b832fe0
--- /dev/null
@@ -0,0 +1,1133 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Azoteq IQS550/572/525 Trackpad/Touchscreen Controller
+ *
+ * Copyright (C) 2018
+ * Author: Jeff LaBundy <jeff@labundy.com>
+ *
+ * These devices require firmware exported from a PC-based configuration tool
+ * made available by the vendor. Firmware files may be pushed to the device's
+ * nonvolatile memory by writing the filename to the 'fw_file' sysfs control.
+ *
+ * Link to PC-based configuration tool and data sheet: http://www.azoteq.com/
+ */
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/firmware.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/input.h>
+#include <linux/input/mt.h>
+#include <linux/input/touchscreen.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/slab.h>
+#include <asm/unaligned.h>
+
+#define IQS5XX_FW_FILE_LEN     64
+#define IQS5XX_NUM_RETRIES     10
+#define IQS5XX_NUM_POINTS      256
+#define IQS5XX_NUM_CONTACTS    5
+#define IQS5XX_WR_BYTES_MAX    2
+
+#define IQS5XX_PROD_NUM_IQS550 40
+#define IQS5XX_PROD_NUM_IQS572 58
+#define IQS5XX_PROD_NUM_IQS525 52
+#define IQS5XX_PROJ_NUM_A000   0
+#define IQS5XX_PROJ_NUM_B000   15
+#define IQS5XX_MAJOR_VER_MIN   2
+
+#define IQS5XX_RESUME          0x00
+#define IQS5XX_SUSPEND         0x01
+
+#define IQS5XX_SW_INPUT_EVENT  0x10
+#define IQS5XX_SETUP_COMPLETE  0x40
+#define IQS5XX_EVENT_MODE      0x01
+#define IQS5XX_TP_EVENT                0x04
+
+#define IQS5XX_FLIP_X          0x01
+#define IQS5XX_FLIP_Y          0x02
+#define IQS5XX_SWITCH_XY_AXIS  0x04
+
+#define IQS5XX_PROD_NUM                0x0000
+#define IQS5XX_ABS_X           0x0016
+#define IQS5XX_ABS_Y           0x0018
+#define IQS5XX_SYS_CTRL0       0x0431
+#define IQS5XX_SYS_CTRL1       0x0432
+#define IQS5XX_SYS_CFG0                0x058E
+#define IQS5XX_SYS_CFG1                0x058F
+#define IQS5XX_TOTAL_RX                0x063D
+#define IQS5XX_TOTAL_TX                0x063E
+#define IQS5XX_XY_CFG0         0x0669
+#define IQS5XX_X_RES           0x066E
+#define IQS5XX_Y_RES           0x0670
+#define IQS5XX_CHKSM           0x83C0
+#define IQS5XX_APP             0x8400
+#define IQS5XX_CSTM            0xBE00
+#define IQS5XX_PMAP_END                0xBFFF
+#define IQS5XX_END_COMM                0xEEEE
+
+#define IQS5XX_CHKSM_LEN       (IQS5XX_APP - IQS5XX_CHKSM)
+#define IQS5XX_APP_LEN         (IQS5XX_CSTM - IQS5XX_APP)
+#define IQS5XX_CSTM_LEN                (IQS5XX_PMAP_END + 1 - IQS5XX_CSTM)
+#define IQS5XX_PMAP_LEN                (IQS5XX_PMAP_END + 1 - IQS5XX_CHKSM)
+
+#define IQS5XX_REC_HDR_LEN     4
+#define IQS5XX_REC_LEN_MAX     255
+#define IQS5XX_REC_TYPE_DATA   0x00
+#define IQS5XX_REC_TYPE_EOF    0x01
+
+#define IQS5XX_BL_ADDR_MASK    0x40
+#define IQS5XX_BL_CMD_VER      0x00
+#define IQS5XX_BL_CMD_READ     0x01
+#define IQS5XX_BL_CMD_EXEC     0x02
+#define IQS5XX_BL_CMD_CRC      0x03
+#define IQS5XX_BL_BLK_LEN_MAX  64
+#define IQS5XX_BL_ID           0x0200
+#define IQS5XX_BL_STATUS_RESET 0x00
+#define IQS5XX_BL_STATUS_AVAIL 0xA5
+#define IQS5XX_BL_STATUS_NONE  0xEE
+#define IQS5XX_BL_CRC_PASS     0x00
+#define IQS5XX_BL_CRC_FAIL     0x01
+#define IQS5XX_BL_ATTEMPTS     3
+
+struct iqs5xx_private {
+       struct i2c_client *client;
+       struct input_dev *input;
+       struct gpio_desc *reset_gpio;
+       struct mutex lock;
+       u8 bl_status;
+};
+
+struct iqs5xx_dev_id_info {
+       __be16 prod_num;
+       __be16 proj_num;
+       u8 major_ver;
+       u8 minor_ver;
+       u8 bl_status;
+} __packed;
+
+struct iqs5xx_ihex_rec {
+       char start;
+       char len[2];
+       char addr[4];
+       char type[2];
+       char data[2];
+} __packed;
+
+struct iqs5xx_touch_data {
+       __be16 abs_x;
+       __be16 abs_y;
+       __be16 strength;
+       u8 area;
+} __packed;
+
+static int iqs5xx_read_burst(struct i2c_client *client,
+                            u16 reg, void *val, u16 len)
+{
+       __be16 reg_buf = cpu_to_be16(reg);
+       int ret, i;
+       struct i2c_msg msg[] = {
+               {
+                       .addr = client->addr,
+                       .flags = 0,
+                       .len = sizeof(reg_buf),
+                       .buf = (u8 *)&reg_buf,
+               },
+               {
+                       .addr = client->addr,
+                       .flags = I2C_M_RD,
+                       .len = len,
+                       .buf = (u8 *)val,
+               },
+       };
+
+       /*
+        * The first addressing attempt outside of a communication window fails
+        * and must be retried, after which the device clock stretches until it
+        * is available.
+        */
+       for (i = 0; i < IQS5XX_NUM_RETRIES; i++) {
+               ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
+               if (ret == ARRAY_SIZE(msg))
+                       return 0;
+
+               usleep_range(200, 300);
+       }
+
+       if (ret >= 0)
+               ret = -EIO;
+
+       dev_err(&client->dev, "Failed to read from address 0x%04X: %d\n",
+               reg, ret);
+
+       return ret;
+}
+
+static int iqs5xx_read_word(struct i2c_client *client, u16 reg, u16 *val)
+{
+       __be16 val_buf;
+       int error;
+
+       error = iqs5xx_read_burst(client, reg, &val_buf, sizeof(val_buf));
+       if (error)
+               return error;
+
+       *val = be16_to_cpu(val_buf);
+
+       return 0;
+}
+
+static int iqs5xx_read_byte(struct i2c_client *client, u16 reg, u8 *val)
+{
+       return iqs5xx_read_burst(client, reg, val, sizeof(*val));
+}
+
+static int iqs5xx_write_burst(struct i2c_client *client,
+                             u16 reg, const void *val, u16 len)
+{
+       int ret, i;
+       u16 mlen = sizeof(reg) + len;
+       u8 mbuf[sizeof(reg) + IQS5XX_WR_BYTES_MAX];
+
+       if (len > IQS5XX_WR_BYTES_MAX)
+               return -EINVAL;
+
+       put_unaligned_be16(reg, mbuf);
+       memcpy(mbuf + sizeof(reg), val, len);
+
+       /*
+        * The first addressing attempt outside of a communication window fails
+        * and must be retried, after which the device clock stretches until it
+        * is available.
+        */
+       for (i = 0; i < IQS5XX_NUM_RETRIES; i++) {
+               ret = i2c_master_send(client, mbuf, mlen);
+               if (ret == mlen)
+                       return 0;
+
+               usleep_range(200, 300);
+       }
+
+       if (ret >= 0)
+               ret = -EIO;
+
+       dev_err(&client->dev, "Failed to write to address 0x%04X: %d\n",
+               reg, ret);
+
+       return ret;
+}
+
+static int iqs5xx_write_word(struct i2c_client *client, u16 reg, u16 val)
+{
+       __be16 val_buf = cpu_to_be16(val);
+
+       return iqs5xx_write_burst(client, reg, &val_buf, sizeof(val_buf));
+}
+
+static int iqs5xx_write_byte(struct i2c_client *client, u16 reg, u8 val)
+{
+       return iqs5xx_write_burst(client, reg, &val, sizeof(val));
+}
+
+static void iqs5xx_reset(struct i2c_client *client)
+{
+       struct iqs5xx_private *iqs5xx = i2c_get_clientdata(client);
+
+       gpiod_set_value_cansleep(iqs5xx->reset_gpio, 1);
+       usleep_range(200, 300);
+
+       gpiod_set_value_cansleep(iqs5xx->reset_gpio, 0);
+}
+
+static int iqs5xx_bl_cmd(struct i2c_client *client, u8 bl_cmd, u16 bl_addr)
+{
+       struct i2c_msg msg;
+       int ret;
+       u8 mbuf[sizeof(bl_cmd) + sizeof(bl_addr)];
+
+       msg.addr = client->addr ^ IQS5XX_BL_ADDR_MASK;
+       msg.flags = 0;
+       msg.len = sizeof(bl_cmd);
+       msg.buf = mbuf;
+
+       *mbuf = bl_cmd;
+
+       switch (bl_cmd) {
+       case IQS5XX_BL_CMD_VER:
+       case IQS5XX_BL_CMD_CRC:
+       case IQS5XX_BL_CMD_EXEC:
+               break;
+       case IQS5XX_BL_CMD_READ:
+               msg.len += sizeof(bl_addr);
+               put_unaligned_be16(bl_addr, mbuf + sizeof(bl_cmd));
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       ret = i2c_transfer(client->adapter, &msg, 1);
+       if (ret != 1)
+               goto msg_fail;
+
+       switch (bl_cmd) {
+       case IQS5XX_BL_CMD_VER:
+               msg.len = sizeof(u16);
+               break;
+       case IQS5XX_BL_CMD_CRC:
+               msg.len = sizeof(u8);
+               /*
+                * This delay saves the bus controller the trouble of having to
+                * tolerate a relatively long clock-stretching period while the
+                * CRC is calculated.
+                */
+               msleep(50);
+               break;
+       case IQS5XX_BL_CMD_EXEC:
+               usleep_range(10000, 10100);
+               /* fall through */
+       default:
+               return 0;
+       }
+
+       msg.flags = I2C_M_RD;
+
+       ret = i2c_transfer(client->adapter, &msg, 1);
+       if (ret != 1)
+               goto msg_fail;
+
+       if (bl_cmd == IQS5XX_BL_CMD_VER &&
+           get_unaligned_be16(mbuf) != IQS5XX_BL_ID) {
+               dev_err(&client->dev, "Unrecognized bootloader ID: 0x%04X\n",
+                       get_unaligned_be16(mbuf));
+               return -EINVAL;
+       }
+
+       if (bl_cmd == IQS5XX_BL_CMD_CRC && *mbuf != IQS5XX_BL_CRC_PASS) {
+               dev_err(&client->dev, "Bootloader CRC failed\n");
+               return -EIO;
+       }
+
+       return 0;
+
+msg_fail:
+       if (ret >= 0)
+               ret = -EIO;
+
+       if (bl_cmd != IQS5XX_BL_CMD_VER)
+               dev_err(&client->dev,
+                       "Unsuccessful bootloader command 0x%02X: %d\n",
+                       bl_cmd, ret);
+
+       return ret;
+}
+
+static int iqs5xx_bl_open(struct i2c_client *client)
+{
+       int error, i, j;
+
+       /*
+        * The device opens a bootloader polling window for 2 ms following the
+        * release of reset. If the host cannot establish communication during
+        * this time frame, it must cycle reset again.
+        */
+       for (i = 0; i < IQS5XX_BL_ATTEMPTS; i++) {
+               iqs5xx_reset(client);
+
+               for (j = 0; j < IQS5XX_NUM_RETRIES; j++) {
+                       error = iqs5xx_bl_cmd(client, IQS5XX_BL_CMD_VER, 0);
+                       if (!error || error == -EINVAL)
+                               return error;
+               }
+       }
+
+       dev_err(&client->dev, "Failed to open bootloader: %d\n", error);
+
+       return error;
+}
+
+static int iqs5xx_bl_write(struct i2c_client *client,
+                          u16 bl_addr, u8 *pmap_data, u16 pmap_len)
+{
+       struct i2c_msg msg;
+       int ret, i;
+       u8 mbuf[sizeof(bl_addr) + IQS5XX_BL_BLK_LEN_MAX];
+
+       if (pmap_len % IQS5XX_BL_BLK_LEN_MAX)
+               return -EINVAL;
+
+       msg.addr = client->addr ^ IQS5XX_BL_ADDR_MASK;
+       msg.flags = 0;
+       msg.len = sizeof(mbuf);
+       msg.buf = mbuf;
+
+       for (i = 0; i < pmap_len; i += IQS5XX_BL_BLK_LEN_MAX) {
+               put_unaligned_be16(bl_addr + i, mbuf);
+               memcpy(mbuf + sizeof(bl_addr), pmap_data + i,
+                      sizeof(mbuf) - sizeof(bl_addr));
+
+               ret = i2c_transfer(client->adapter, &msg, 1);
+               if (ret != 1)
+                       goto msg_fail;
+
+               usleep_range(10000, 10100);
+       }
+
+       return 0;
+
+msg_fail:
+       if (ret >= 0)
+               ret = -EIO;
+
+       dev_err(&client->dev, "Failed to write block at address 0x%04X: %d\n",
+               bl_addr + i, ret);
+
+       return ret;
+}
+
+static int iqs5xx_bl_verify(struct i2c_client *client,
+                           u16 bl_addr, u8 *pmap_data, u16 pmap_len)
+{
+       struct i2c_msg msg;
+       int ret, i;
+       u8 bl_data[IQS5XX_BL_BLK_LEN_MAX];
+
+       if (pmap_len % IQS5XX_BL_BLK_LEN_MAX)
+               return -EINVAL;
+
+       msg.addr = client->addr ^ IQS5XX_BL_ADDR_MASK;
+       msg.flags = I2C_M_RD;
+       msg.len = sizeof(bl_data);
+       msg.buf = bl_data;
+
+       for (i = 0; i < pmap_len; i += IQS5XX_BL_BLK_LEN_MAX) {
+               ret = iqs5xx_bl_cmd(client, IQS5XX_BL_CMD_READ, bl_addr + i);
+               if (ret)
+                       return ret;
+
+               ret = i2c_transfer(client->adapter, &msg, 1);
+               if (ret != 1)
+                       goto msg_fail;
+
+               if (memcmp(bl_data, pmap_data + i, sizeof(bl_data))) {
+                       dev_err(&client->dev,
+                               "Failed to verify block at address 0x%04X\n",
+                               bl_addr + i);
+                       return -EIO;
+               }
+       }
+
+       return 0;
+
+msg_fail:
+       if (ret >= 0)
+               ret = -EIO;
+
+       dev_err(&client->dev, "Failed to read block at address 0x%04X: %d\n",
+               bl_addr + i, ret);
+
+       return ret;
+}
+
+static int iqs5xx_set_state(struct i2c_client *client, u8 state)
+{
+       struct iqs5xx_private *iqs5xx = i2c_get_clientdata(client);
+       int error1, error2;
+
+       if (iqs5xx->bl_status == IQS5XX_BL_STATUS_RESET)
+               return 0;
+
+       mutex_lock(&iqs5xx->lock);
+
+       /*
+        * Addressing the device outside of a communication window prompts it
+        * to assert the RDY output, so disable the interrupt line to prevent
+        * the handler from servicing a false interrupt.
+        */
+       disable_irq(client->irq);
+
+       error1 = iqs5xx_write_byte(client, IQS5XX_SYS_CTRL1, state);
+       error2 = iqs5xx_write_byte(client, IQS5XX_END_COMM, 0);
+
+       usleep_range(50, 100);
+       enable_irq(client->irq);
+
+       mutex_unlock(&iqs5xx->lock);
+
+       if (error1)
+               return error1;
+
+       return error2;
+}
+
+static int iqs5xx_open(struct input_dev *input)
+{
+       struct iqs5xx_private *iqs5xx = input_get_drvdata(input);
+
+       return iqs5xx_set_state(iqs5xx->client, IQS5XX_RESUME);
+}
+
+static void iqs5xx_close(struct input_dev *input)
+{
+       struct iqs5xx_private *iqs5xx = input_get_drvdata(input);
+
+       iqs5xx_set_state(iqs5xx->client, IQS5XX_SUSPEND);
+}
+
+static int iqs5xx_axis_init(struct i2c_client *client)
+{
+       struct iqs5xx_private *iqs5xx = i2c_get_clientdata(client);
+       struct touchscreen_properties prop;
+       struct input_dev *input;
+       int error;
+       u16 max_x, max_x_hw;
+       u16 max_y, max_y_hw;
+       u8 val;
+
+       if (!iqs5xx->input) {
+               input = devm_input_allocate_device(&client->dev);
+               if (!input)
+                       return -ENOMEM;
+
+               input->name = client->name;
+               input->id.bustype = BUS_I2C;
+               input->open = iqs5xx_open;
+               input->close = iqs5xx_close;
+
+               input_set_capability(input, EV_ABS, ABS_MT_POSITION_X);
+               input_set_capability(input, EV_ABS, ABS_MT_POSITION_Y);
+               input_set_capability(input, EV_ABS, ABS_MT_PRESSURE);
+
+               error = input_mt_init_slots(input,
+                               IQS5XX_NUM_CONTACTS, INPUT_MT_DIRECT);
+               if (error) {
+                       dev_err(&client->dev,
+                               "Failed to initialize slots: %d\n", error);
+                       return error;
+               }
+
+               input_set_drvdata(input, iqs5xx);
+               iqs5xx->input = input;
+       }
+
+       touchscreen_parse_properties(iqs5xx->input, true, &prop);
+
+       error = iqs5xx_read_byte(client, IQS5XX_TOTAL_RX, &val);
+       if (error)
+               return error;
+       max_x_hw = (val - 1) * IQS5XX_NUM_POINTS;
+
+       error = iqs5xx_read_byte(client, IQS5XX_TOTAL_TX, &val);
+       if (error)
+               return error;
+       max_y_hw = (val - 1) * IQS5XX_NUM_POINTS;
+
+       error = iqs5xx_read_byte(client, IQS5XX_XY_CFG0, &val);
+       if (error)
+               return error;
+
+       if (val & IQS5XX_SWITCH_XY_AXIS)
+               swap(max_x_hw, max_y_hw);
+
+       if (prop.swap_x_y)
+               val ^= IQS5XX_SWITCH_XY_AXIS;
+
+       if (prop.invert_x)
+               val ^= prop.swap_x_y ? IQS5XX_FLIP_Y : IQS5XX_FLIP_X;
+
+       if (prop.invert_y)
+               val ^= prop.swap_x_y ? IQS5XX_FLIP_X : IQS5XX_FLIP_Y;
+
+       error = iqs5xx_write_byte(client, IQS5XX_XY_CFG0, val);
+       if (error)
+               return error;
+
+       if (prop.max_x > max_x_hw) {
+               dev_err(&client->dev, "Invalid maximum x-coordinate: %u > %u\n",
+                       prop.max_x, max_x_hw);
+               return -EINVAL;
+       } else if (prop.max_x == 0) {
+               error = iqs5xx_read_word(client, IQS5XX_X_RES, &max_x);
+               if (error)
+                       return error;
+
+               input_abs_set_max(iqs5xx->input,
+                                 prop.swap_x_y ? ABS_MT_POSITION_Y :
+                                                 ABS_MT_POSITION_X,
+                                 max_x);
+       } else {
+               max_x = (u16)prop.max_x;
+       }
+
+       if (prop.max_y > max_y_hw) {
+               dev_err(&client->dev, "Invalid maximum y-coordinate: %u > %u\n",
+                       prop.max_y, max_y_hw);
+               return -EINVAL;
+       } else if (prop.max_y == 0) {
+               error = iqs5xx_read_word(client, IQS5XX_Y_RES, &max_y);
+               if (error)
+                       return error;
+
+               input_abs_set_max(iqs5xx->input,
+                                 prop.swap_x_y ? ABS_MT_POSITION_X :
+                                                 ABS_MT_POSITION_Y,
+                                 max_y);
+       } else {
+               max_y = (u16)prop.max_y;
+       }
+
+       /*
+        * Write horizontal and vertical resolution to the device in case its
+        * original defaults were overridden or swapped as per the properties
+        * specified in the device tree.
+        */
+       error = iqs5xx_write_word(client,
+                                 prop.swap_x_y ? IQS5XX_Y_RES : IQS5XX_X_RES,
+                                 max_x);
+       if (error)
+               return error;
+
+       return iqs5xx_write_word(client,
+                                prop.swap_x_y ? IQS5XX_X_RES : IQS5XX_Y_RES,
+                                max_y);
+}
+
+static int iqs5xx_dev_init(struct i2c_client *client)
+{
+       struct iqs5xx_private *iqs5xx = i2c_get_clientdata(client);
+       struct iqs5xx_dev_id_info *dev_id_info;
+       int error;
+       u8 val;
+       u8 buf[sizeof(*dev_id_info) + 1];
+
+       error = iqs5xx_read_burst(client, IQS5XX_PROD_NUM,
+                                 &buf[1], sizeof(*dev_id_info));
+       if (error)
+               return iqs5xx_bl_open(client);
+
+       /*
+        * A000 and B000 devices use 8-bit and 16-bit addressing, respectively.
+        * Querying an A000 device's version information with 16-bit addressing
+        * gives the appearance that the data is shifted by one byte; a nonzero
+        * leading array element suggests this could be the case (in which case
+        * the missing zero is prepended).
+        */
+       buf[0] = 0;
+       dev_id_info = (struct iqs5xx_dev_id_info *)&buf[(buf[1] > 0) ? 0 : 1];
+
+       switch (be16_to_cpu(dev_id_info->prod_num)) {
+       case IQS5XX_PROD_NUM_IQS550:
+       case IQS5XX_PROD_NUM_IQS572:
+       case IQS5XX_PROD_NUM_IQS525:
+               break;
+       default:
+               dev_err(&client->dev, "Unrecognized product number: %u\n",
+                       be16_to_cpu(dev_id_info->prod_num));
+               return -EINVAL;
+       }
+
+       switch (be16_to_cpu(dev_id_info->proj_num)) {
+       case IQS5XX_PROJ_NUM_A000:
+               dev_err(&client->dev, "Unsupported project number: %u\n",
+                       be16_to_cpu(dev_id_info->proj_num));
+               return iqs5xx_bl_open(client);
+       case IQS5XX_PROJ_NUM_B000:
+               break;
+       default:
+               dev_err(&client->dev, "Unrecognized project number: %u\n",
+                       be16_to_cpu(dev_id_info->proj_num));
+               return -EINVAL;
+       }
+
+       if (dev_id_info->major_ver < IQS5XX_MAJOR_VER_MIN) {
+               dev_err(&client->dev, "Unsupported major version: %u\n",
+                       dev_id_info->major_ver);
+               return iqs5xx_bl_open(client);
+       }
+
+       switch (dev_id_info->bl_status) {
+       case IQS5XX_BL_STATUS_AVAIL:
+       case IQS5XX_BL_STATUS_NONE:
+               break;
+       default:
+               dev_err(&client->dev,
+                       "Unrecognized bootloader status: 0x%02X\n",
+                       dev_id_info->bl_status);
+               return -EINVAL;
+       }
+
+       error = iqs5xx_axis_init(client);
+       if (error)
+               return error;
+
+       error = iqs5xx_read_byte(client, IQS5XX_SYS_CFG0, &val);
+       if (error)
+               return error;
+
+       val |= IQS5XX_SETUP_COMPLETE;
+       val &= ~IQS5XX_SW_INPUT_EVENT;
+       error = iqs5xx_write_byte(client, IQS5XX_SYS_CFG0, val);
+       if (error)
+               return error;
+
+       val = IQS5XX_TP_EVENT | IQS5XX_EVENT_MODE;
+       error = iqs5xx_write_byte(client, IQS5XX_SYS_CFG1, val);
+       if (error)
+               return error;
+
+       error = iqs5xx_write_byte(client, IQS5XX_END_COMM, 0);
+       if (error)
+               return error;
+
+       iqs5xx->bl_status = dev_id_info->bl_status;
+
+       /*
+        * Closure of the first communication window that appears following the
+        * release of reset appears to kick off an initialization period during
+        * which further communication is met with clock stretching. The return
+        * from this function is delayed so that further communication attempts
+        * avoid this period.
+        */
+       msleep(100);
+
+       return 0;
+}
+
+static irqreturn_t iqs5xx_irq(int irq, void *data)
+{
+       struct iqs5xx_private *iqs5xx = data;
+       struct iqs5xx_touch_data touch_data[IQS5XX_NUM_CONTACTS];
+       struct i2c_client *client = iqs5xx->client;
+       struct input_dev *input = iqs5xx->input;
+       int error, i;
+
+       /*
+        * This check is purely a precaution, as the device does not assert the
+        * RDY output during bootloader mode. If the device operates outside of
+        * bootloader mode, the input device is guaranteed to be allocated.
+        */
+       if (iqs5xx->bl_status == IQS5XX_BL_STATUS_RESET)
+               return IRQ_NONE;
+
+       error = iqs5xx_read_burst(client, IQS5XX_ABS_X,
+                                 touch_data, sizeof(touch_data));
+       if (error)
+               return IRQ_NONE;
+
+       for (i = 0; i < ARRAY_SIZE(touch_data); i++) {
+               u16 pressure = be16_to_cpu(touch_data[i].strength);
+
+               input_mt_slot(input, i);
+               if (input_mt_report_slot_state(input, MT_TOOL_FINGER,
+                                              pressure != 0)) {
+                       input_report_abs(input, ABS_MT_POSITION_X,
+                                        be16_to_cpu(touch_data[i].abs_x));
+                       input_report_abs(input, ABS_MT_POSITION_Y,
+                                        be16_to_cpu(touch_data[i].abs_y));
+                       input_report_abs(input, ABS_MT_PRESSURE, pressure);
+               }
+       }
+
+       input_mt_sync_frame(input);
+       input_sync(input);
+
+       error = iqs5xx_write_byte(client, IQS5XX_END_COMM, 0);
+       if (error)
+               return IRQ_NONE;
+
+       /*
+        * Once the communication window is closed, a small delay is added to
+        * ensure the device's RDY output has been deasserted by the time the
+        * interrupt handler returns.
+        */
+       usleep_range(50, 100);
+
+       return IRQ_HANDLED;
+}
+
+static int iqs5xx_fw_file_parse(struct i2c_client *client,
+                               const char *fw_file, u8 *pmap)
+{
+       const struct firmware *fw;
+       struct iqs5xx_ihex_rec *rec;
+       size_t pos = 0;
+       int error, i;
+       u16 rec_num = 1;
+       u16 rec_addr;
+       u8 rec_len, rec_type, rec_chksm, chksm;
+       u8 rec_hdr[IQS5XX_REC_HDR_LEN];
+       u8 rec_data[IQS5XX_REC_LEN_MAX];
+
+       /*
+        * Firmware exported from the vendor's configuration tool deviates from
+        * standard ihex as follows: (1) the checksum for records corresponding
+        * to user-exported settings is not recalculated, and (2) an address of
+        * 0xFFFF is used for the EOF record.
+        *
+        * Because the ihex2fw tool tolerates neither (1) nor (2), the slightly
+        * nonstandard ihex firmware is parsed directly by the driver.
+        */
+       error = request_firmware(&fw, fw_file, &client->dev);
+       if (error) {
+               dev_err(&client->dev, "Failed to request firmware %s: %d\n",
+                       fw_file, error);
+               return error;
+       }
+
+       do {
+               if (pos + sizeof(*rec) > fw->size) {
+                       dev_err(&client->dev, "Insufficient firmware size\n");
+                       error = -EINVAL;
+                       break;
+               }
+               rec = (struct iqs5xx_ihex_rec *)(fw->data + pos);
+               pos += sizeof(*rec);
+
+               if (rec->start != ':') {
+                       dev_err(&client->dev, "Invalid start at record %u\n",
+                               rec_num);
+                       error = -EINVAL;
+                       break;
+               }
+
+               error = hex2bin(rec_hdr, rec->len, sizeof(rec_hdr));
+               if (error) {
+                       dev_err(&client->dev, "Invalid header at record %u\n",
+                               rec_num);
+                       break;
+               }
+
+               rec_len = *rec_hdr;
+               rec_addr = get_unaligned_be16(rec_hdr + sizeof(rec_len));
+               rec_type = *(rec_hdr + sizeof(rec_len) + sizeof(rec_addr));
+
+               if (pos + rec_len * 2 > fw->size) {
+                       dev_err(&client->dev, "Insufficient firmware size\n");
+                       error = -EINVAL;
+                       break;
+               }
+               pos += (rec_len * 2);
+
+               error = hex2bin(rec_data, rec->data, rec_len);
+               if (error) {
+                       dev_err(&client->dev, "Invalid data at record %u\n",
+                               rec_num);
+                       break;
+               }
+
+               error = hex2bin(&rec_chksm,
+                               rec->data + rec_len * 2, sizeof(rec_chksm));
+               if (error) {
+                       dev_err(&client->dev, "Invalid checksum at record %u\n",
+                               rec_num);
+                       break;
+               }
+
+               chksm = 0;
+               for (i = 0; i < sizeof(rec_hdr); i++)
+                       chksm += rec_hdr[i];
+               for (i = 0; i < rec_len; i++)
+                       chksm += rec_data[i];
+               chksm = ~chksm + 1;
+
+               if (chksm != rec_chksm && rec_addr < IQS5XX_CSTM) {
+                       dev_err(&client->dev,
+                               "Incorrect checksum at record %u\n",
+                               rec_num);
+                       error = -EINVAL;
+                       break;
+               }
+
+               switch (rec_type) {
+               case IQS5XX_REC_TYPE_DATA:
+                       if (rec_addr < IQS5XX_CHKSM ||
+                           rec_addr > IQS5XX_PMAP_END) {
+                               dev_err(&client->dev,
+                                       "Invalid address at record %u\n",
+                                       rec_num);
+                               error = -EINVAL;
+                       } else {
+                               memcpy(pmap + rec_addr - IQS5XX_CHKSM,
+                                      rec_data, rec_len);
+                       }
+                       break;
+               case IQS5XX_REC_TYPE_EOF:
+                       break;
+               default:
+                       dev_err(&client->dev, "Invalid type at record %u\n",
+                               rec_num);
+                       error = -EINVAL;
+               }
+
+               if (error)
+                       break;
+
+               rec_num++;
+               while (pos < fw->size) {
+                       if (*(fw->data + pos) == ':')
+                               break;
+                       pos++;
+               }
+       } while (rec_type != IQS5XX_REC_TYPE_EOF);
+
+       release_firmware(fw);
+
+       return error;
+}
+
+static int iqs5xx_fw_file_write(struct i2c_client *client, const char *fw_file)
+{
+       struct iqs5xx_private *iqs5xx = i2c_get_clientdata(client);
+       int error;
+       u8 *pmap;
+
+       if (iqs5xx->bl_status == IQS5XX_BL_STATUS_NONE)
+               return -EPERM;
+
+       pmap = kzalloc(IQS5XX_PMAP_LEN, GFP_KERNEL);
+       if (!pmap)
+               return -ENOMEM;
+
+       error = iqs5xx_fw_file_parse(client, fw_file, pmap);
+       if (error)
+               goto err_kfree;
+
+       mutex_lock(&iqs5xx->lock);
+
+       /*
+        * Disable the interrupt line in case the first attempt(s) to enter the
+        * bootloader don't happen quickly enough, in which case the device may
+        * assert the RDY output until the next attempt.
+        */
+       disable_irq(client->irq);
+
+       iqs5xx->bl_status = IQS5XX_BL_STATUS_RESET;
+
+       error = iqs5xx_bl_cmd(client, IQS5XX_BL_CMD_VER, 0);
+       if (error) {
+               error = iqs5xx_bl_open(client);
+               if (error)
+                       goto err_reset;
+       }
+
+       error = iqs5xx_bl_write(client, IQS5XX_CHKSM, pmap, IQS5XX_PMAP_LEN);
+       if (error)
+               goto err_reset;
+
+       error = iqs5xx_bl_cmd(client, IQS5XX_BL_CMD_CRC, 0);
+       if (error)
+               goto err_reset;
+
+       error = iqs5xx_bl_verify(client, IQS5XX_CSTM,
+                                pmap + IQS5XX_CHKSM_LEN + IQS5XX_APP_LEN,
+                                IQS5XX_CSTM_LEN);
+       if (error)
+               goto err_reset;
+
+       error = iqs5xx_bl_cmd(client, IQS5XX_BL_CMD_EXEC, 0);
+
+err_reset:
+       if (error) {
+               iqs5xx_reset(client);
+               usleep_range(10000, 10100);
+       }
+
+       error = iqs5xx_dev_init(client);
+       if (!error && iqs5xx->bl_status == IQS5XX_BL_STATUS_RESET)
+               error = -EINVAL;
+
+       enable_irq(client->irq);
+
+       mutex_unlock(&iqs5xx->lock);
+
+err_kfree:
+       kfree(pmap);
+
+       return error;
+}
+
+static ssize_t fw_file_store(struct device *dev, struct device_attribute *attr,
+                               const char *buf, size_t count)
+{
+       struct iqs5xx_private *iqs5xx = dev_get_drvdata(dev);
+       struct i2c_client *client = iqs5xx->client;
+       size_t len = count;
+       bool input_reg = !iqs5xx->input;
+       char fw_file[IQS5XX_FW_FILE_LEN + 1];
+       int error;
+
+       if (!len)
+               return -EINVAL;
+
+       if (buf[len - 1] == '\n')
+               len--;
+
+       if (len > IQS5XX_FW_FILE_LEN)
+               return -ENAMETOOLONG;
+
+       memcpy(fw_file, buf, len);
+       fw_file[len] = '\0';
+
+       error = iqs5xx_fw_file_write(client, fw_file);
+       if (error)
+               return error;
+
+       /*
+        * If the input device was not allocated already, it is guaranteed to
+        * be allocated by this point and can finally be registered.
+        */
+       if (input_reg) {
+               error = input_register_device(iqs5xx->input);
+               if (error) {
+                       dev_err(&client->dev,
+                               "Failed to register device: %d\n",
+                               error);
+                       return error;
+               }
+       }
+
+       return count;
+}
+
+static DEVICE_ATTR_WO(fw_file);
+
+static struct attribute *iqs5xx_attrs[] = {
+       &dev_attr_fw_file.attr,
+       NULL,
+};
+
+static const struct attribute_group iqs5xx_attr_group = {
+       .attrs = iqs5xx_attrs,
+};
+
+static int __maybe_unused iqs5xx_suspend(struct device *dev)
+{
+       struct iqs5xx_private *iqs5xx = dev_get_drvdata(dev);
+       struct input_dev *input = iqs5xx->input;
+       int error = 0;
+
+       if (!input)
+               return error;
+
+       mutex_lock(&input->mutex);
+
+       if (input->users)
+               error = iqs5xx_set_state(iqs5xx->client, IQS5XX_SUSPEND);
+
+       mutex_unlock(&input->mutex);
+
+       return error;
+}
+
+static int __maybe_unused iqs5xx_resume(struct device *dev)
+{
+       struct iqs5xx_private *iqs5xx = dev_get_drvdata(dev);
+       struct input_dev *input = iqs5xx->input;
+       int error = 0;
+
+       if (!input)
+               return error;
+
+       mutex_lock(&input->mutex);
+
+       if (input->users)
+               error = iqs5xx_set_state(iqs5xx->client, IQS5XX_RESUME);
+
+       mutex_unlock(&input->mutex);
+
+       return error;
+}
+
+static SIMPLE_DEV_PM_OPS(iqs5xx_pm, iqs5xx_suspend, iqs5xx_resume);
+
+static int iqs5xx_probe(struct i2c_client *client,
+                       const struct i2c_device_id *id)
+{
+       struct iqs5xx_private *iqs5xx;
+       int error;
+
+       iqs5xx = devm_kzalloc(&client->dev, sizeof(*iqs5xx), GFP_KERNEL);
+       if (!iqs5xx)
+               return -ENOMEM;
+
+       dev_set_drvdata(&client->dev, iqs5xx);
+
+       i2c_set_clientdata(client, iqs5xx);
+       iqs5xx->client = client;
+
+       iqs5xx->reset_gpio = devm_gpiod_get(&client->dev,
+                                           "reset", GPIOD_OUT_LOW);
+       if (IS_ERR(iqs5xx->reset_gpio)) {
+               error = PTR_ERR(iqs5xx->reset_gpio);
+               dev_err(&client->dev, "Failed to request GPIO: %d\n", error);
+               return error;
+       }
+
+       mutex_init(&iqs5xx->lock);
+
+       iqs5xx_reset(client);
+       usleep_range(10000, 10100);
+
+       error = iqs5xx_dev_init(client);
+       if (error)
+               return error;
+
+       error = devm_request_threaded_irq(&client->dev, client->irq,
+                                         NULL, iqs5xx_irq, IRQF_ONESHOT,
+                                         client->name, iqs5xx);
+       if (error) {
+               dev_err(&client->dev, "Failed to request IRQ: %d\n", error);
+               return error;
+       }
+
+       error = devm_device_add_group(&client->dev, &iqs5xx_attr_group);
+       if (error) {
+               dev_err(&client->dev, "Failed to add attributes: %d\n", error);
+               return error;
+       }
+
+       if (iqs5xx->input) {
+               error = input_register_device(iqs5xx->input);
+               if (error)
+                       dev_err(&client->dev,
+                               "Failed to register device: %d\n",
+                               error);
+       }
+
+       return error;
+}
+
+static const struct i2c_device_id iqs5xx_id[] = {
+       { "iqs550", 0 },
+       { "iqs572", 1 },
+       { "iqs525", 2 },
+       { }
+};
+MODULE_DEVICE_TABLE(i2c, iqs5xx_id);
+
+static const struct of_device_id iqs5xx_of_match[] = {
+       { .compatible = "azoteq,iqs550" },
+       { .compatible = "azoteq,iqs572" },
+       { .compatible = "azoteq,iqs525" },
+       { }
+};
+MODULE_DEVICE_TABLE(of, iqs5xx_of_match);
+
+static struct i2c_driver iqs5xx_i2c_driver = {
+       .driver = {
+               .name           = "iqs5xx",
+               .of_match_table = iqs5xx_of_match,
+               .pm             = &iqs5xx_pm,
+       },
+       .id_table       = iqs5xx_id,
+       .probe          = iqs5xx_probe,
+};
+module_i2c_driver(iqs5xx_i2c_driver);
+
+MODULE_AUTHOR("Jeff LaBundy <jeff@labundy.com>");
+MODULE_DESCRIPTION("Azoteq IQS550/572/525 Trackpad/Touchscreen Controller");
+MODULE_LICENSE("GPL");