Add a new driver for the TouchNetix's axiom family of
touchscreen controllers. This driver only supports i2c
and can be later adapted for SPI and USB support.
Signed-off-by: Kamel Bouhara <[email protected]>
---
MAINTAINERS | 1 +
drivers/input/touchscreen/Kconfig | 12 +
drivers/input/touchscreen/Makefile | 1 +
drivers/input/touchscreen/touchnetix_axiom.c | 669 +++++++++++++++++++
4 files changed, 683 insertions(+)
create mode 100644 drivers/input/touchscreen/touchnetix_axiom.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 4b3ed2f22b89..de5fad8f317a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -22262,6 +22262,7 @@ M: Kamel Bouhara <[email protected]>
L: [email protected]
S: Maintained
F: Documentation/devicetree/bindings/input/touchscreen/touchnetix,ax54a.yaml
+F: drivers/input/touchscreen/touchnetix_axiom.c
TPM DEVICE DRIVER
M: Peter Huewe <[email protected]>
diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index e3e2324547b9..f36bee8d8696 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -803,6 +803,18 @@ config TOUCHSCREEN_MIGOR
To compile this driver as a module, choose M here: the
module will be called migor_ts.
+config TOUCHSCREEN_TOUCHNETIX_AXIOM
+ tristate "TouchNetix AXIOM based touchscreen controllers"
+ depends on I2C
+ help
+ Say Y here if you have a axiom touchscreen connected to
+ your system.
+
+ If unsure, say N.
+
+ To compile this driver as a module, choose M here: the
+ module will be called axiom.
+
config TOUCHSCREEN_TOUCHRIGHT
tristate "Touchright serial touchscreen"
select SERIO
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 62bd24f3ac8e..8e32a2df5e18 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -88,6 +88,7 @@ obj-$(CONFIG_TOUCHSCREEN_SUR40) += sur40.o
obj-$(CONFIG_TOUCHSCREEN_SURFACE3_SPI) += surface3_spi.o
obj-$(CONFIG_TOUCHSCREEN_TI_AM335X_TSC) += ti_am335x_tsc.o
obj-$(CONFIG_TOUCHSCREEN_TOUCHIT213) += touchit213.o
+obj-$(CONFIG_TOUCHSCREEN_TOUCHNETIX_AXIOM) += touchnetix_axiom.o
obj-$(CONFIG_TOUCHSCREEN_TOUCHRIGHT) += touchright.o
obj-$(CONFIG_TOUCHSCREEN_TOUCHWIN) += touchwin.o
obj-$(CONFIG_TOUCHSCREEN_TS4800) += ts4800-ts.o
diff --git a/drivers/input/touchscreen/touchnetix_axiom.c b/drivers/input/touchscreen/touchnetix_axiom.c
new file mode 100644
index 000000000000..e7abba41eed0
--- /dev/null
+++ b/drivers/input/touchscreen/touchnetix_axiom.c
@@ -0,0 +1,669 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * TouchNetix axiom Touchscreen Driver
+ *
+ * Copyright (C) 2020-2023 TouchNetix Ltd.
+ *
+ * Author(s): Bart Prescott <[email protected]>
+ * Pedro Torruella <[email protected]>
+ * Mark Satterthwaite <[email protected]>
+ * Hannah Rossiter <[email protected]>
+ * Kamel Bouhara <[email protected]>
+ *
+ */
+#include <linux/bitfield.h>
+#include <linux/crc16.h>
+#include <linux/delay.h>
+#include <linux/device.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/mod_devicetable.h>
+#include <linux/regmap.h>
+
+#include <asm/unaligned.h>
+#define AXIOM_PROX_LEVEL -128
+#define AXIOM_DMA_OPS_DELAY_USEC 250
+#define AXIOM_STARTUP_TIME_MS 110
+/*
+ * Register group u31 has 2 pages for usage table entries.
+ */
+#define AXIOM_U31_MAX_USAGES 0xff
+#define AXIOM_U31_BYTES_PER_USAGE 6
+#define AXIOM_U31_PAGE0_LENGTH 0x0C
+#define AXIOM_U31_BOOTMODE_MASK BIT(7)
+#define AXIOM_U31_DEVID_MASK GENMASK(14, 0)
+
+#define AXIOM_MAX_REPORT_LEN 0x7f
+
+#define AXIOM_CMD_HEADER_READ_MASK BIT(15)
+#define AXIOM_U41_MAX_TARGETS 10
+
+#define AXIOM_U46_AUX_CHANNELS 4
+#define AXIOM_U46_AUX_MASK GENMASK(11, 0)
+
+#define AXIOM_COMMS_MAX_USAGE_PAGES 3
+#define AXIOM_COMMS_PAGE_SIZE 256
+#define AXIOM_COMMS_REPORT_LEN_MASK GENMASK(6, 0)
+
+#define AXIOM_REPORT_USAGE_ID 0x34
+#define AXIOM_DEVINFO_USAGE_ID 0x31
+#define AXIOM_USAGE_2HB_REPORT_ID 0x01
+#define AXIOM_USAGE_2AUX_REPORT_ID 0x46
+#define AXIOM_USAGE_2DCTS_REPORT_ID 0x41
+
+#define AXIOM_PAGE_OFFSET_MASK GENMASK(6, 0)
+
+struct axiom_devinfo {
+ __le16 device_id;
+ u8 fw_minor;
+ u8 fw_major;
+ u8 fw_info_extra;
+ u8 tcp_revision;
+ u8 bootloader_fw_minor;
+ u8 bootloader_fw_major;
+ __le16 jedec_id;
+ u8 num_usages;
+} __packed;
+
+/*
+ * Describes parameters of a specific usage, essentially a single element of
+ * the "Usage Table"
+ */
+struct axiom_usage_entry {
+ u8 id;
+ u8 is_report;
+ u8 start_page;
+ u8 num_pages;
+};
+
+/*
+ * Represents state of a touch or target when detected prior to a touch (eg.
+ * hover or proximity events).
+ */
+enum axiom_target_state {
+ AXIOM_TARGET_STATE_NOT_PRESENT = 0,
+ AXIOM_TARGET_STATE_PROX = 1,
+ AXIOM_TARGET_STATE_HOVER = 2,
+ AXIOM_TARGET_STATE_TOUCHING = 3,
+};
+
+struct axiom_u41_target {
+ enum axiom_target_state state;
+ u16 x;
+ u16 y;
+ s8 z;
+ bool insert;
+ bool touch;
+};
+
+struct axiom_target_report {
+ u8 index;
+ u8 present;
+ u16 x;
+ u16 y;
+ s8 z;
+};
+
+struct axiom_cmd_header {
+ __le16 target_address;
+ __le16 length;
+} __packed;
+
+struct axiom_data {
+ struct axiom_devinfo devinfo;
+ struct device *dev;
+ struct gpio_desc *reset_gpio;
+ struct i2c_client *client;
+ struct input_dev *input_dev;
+ u32 max_report_len;
+ u8 rx_buf[AXIOM_COMMS_MAX_USAGE_PAGES * AXIOM_COMMS_PAGE_SIZE];
+ struct axiom_u41_target targets[AXIOM_U41_MAX_TARGETS];
+ struct axiom_usage_entry usage_table[AXIOM_U31_MAX_USAGES];
+ bool usage_table_populated;
+ struct regulator *vdda;
+ struct regulator *vddi;
+ struct regmap *regmap;
+ struct touchscreen_properties prop;
+};
+
+static const struct regmap_config axiom_i2c_regmap_config = {
+ .reg_bits = 32,
+ .reg_format_endian = REGMAP_ENDIAN_LITTLE,
+ .val_bits = 8,
+ .val_format_endian = REGMAP_ENDIAN_LITTLE,
+};
+
+/*
+ * axiom devices are typically configured to report touches at a rate
+ * of 100Hz (10ms) for systems that require polling for reports.
+ * When reports are polled, it will be expected to occasionally
+ * observe the overflow bit being set in the reports.
+ * This indicates that reports are not being read fast enough.
+ */
+#define POLL_INTERVAL_DEFAULT_MS 10
+
+/* Translate usage/page/offset triplet into physical address. */
+static u16 axiom_usage_to_target_address(struct axiom_data *ts, u8 usage, u8 page,
+ char offset)
+{
+ /* At the moment the convention is that u31 is always at physical address 0x0 */
+ if (!ts->usage_table_populated) {
+ if (usage == AXIOM_DEVINFO_USAGE_ID)
+ return ((page << 8) + offset);
+ else
+ return 0xffff;
+ }
+
+ if (page >= ts->usage_table[usage].num_pages) {
+ dev_err(ts->dev, "Invalid usage table! usage: u%02x, page: %02x, offset: %02x\n",
+ usage, page, offset);
+ return 0xffff;
+ }
+
+ return ((ts->usage_table[usage].start_page + page) << 8) + offset;
+}
+
+static int axiom_read(struct axiom_data *ts, u8 usage, u8 page, void *buf, u16 len)
+{
+ struct axiom_cmd_header cmd_header;
+ u32 preamble;
+ int ret;
+
+ cmd_header.target_address = cpu_to_le16(axiom_usage_to_target_address(ts, usage, page, 0));
+ cmd_header.length = cpu_to_le16(len | AXIOM_CMD_HEADER_READ_MASK);
+
+ preamble = get_unaligned_le32(&cmd_header);
+
+ ret = regmap_write(ts->regmap, preamble, 0);
+ if (ret) {
+ dev_err(ts->dev, "failed to write preamble, error %d\n", ret);
+ return ret;
+ }
+
+ ret = regmap_raw_read(ts->regmap, 0, buf, len);
+ if (ret) {
+ dev_err(ts->dev, "failed to read target address %04x, error %d\n",
+ cmd_header.target_address, ret);
+ return ret;
+ }
+
+ /* Wait device's DMA operations */
+ usleep_range(AXIOM_DMA_OPS_DELAY_USEC, AXIOM_DMA_OPS_DELAY_USEC + 50);
+
+ return 0;
+}
+
+/*
+ * One of the main purposes for reading the usage table is to identify
+ * which usages reside at which target address.
+ * When performing subsequent reads or writes to AXIOM, the target address
+ * is used to specify which usage is being accessed.
+ * Consider the following discovery code which will build up the usage table.
+ */
+static u32 axiom_populate_usage_table(struct axiom_data *ts)
+{
+ struct axiom_usage_entry *usage_table;
+ u8 *rx_data = ts->rx_buf;
+ u32 max_report_len = 0;
+ u32 usage_id;
+ int error;
+
+ usage_table = ts->usage_table;
+
+ /* Read the second page of usage u31 to get the usage table */
+ error = axiom_read(ts, AXIOM_DEVINFO_USAGE_ID, 1, rx_data,
+ (AXIOM_U31_BYTES_PER_USAGE * ts->devinfo.num_usages));
+
+ if (error)
+ return error;
+
+ for (usage_id = 0; usage_id < ts->devinfo.num_usages; usage_id++) {
+ u16 offset = (usage_id * AXIOM_U31_BYTES_PER_USAGE);
+ u8 id = rx_data[offset + 0];
+ u8 start_page = rx_data[offset + 1];
+ u8 num_pages = rx_data[offset + 2];
+ u32 max_offset = ((rx_data[offset + 3] & AXIOM_PAGE_OFFSET_MASK) + 1) * 2;
+
+ usage_table[id].is_report = !num_pages;
+
+ /* Store the entry into the usage table */
+ usage_table[id].id = id;
+ usage_table[id].start_page = start_page;
+ usage_table[id].num_pages = num_pages;
+
+ dev_dbg(ts->dev, "Usage u%02x Info: %*ph\n", id, AXIOM_U31_BYTES_PER_USAGE,
+ &rx_data[offset]);
+
+ /* Identify the max report length the module will receive */
+ if (usage_table[id].is_report && max_offset > max_report_len)
+ max_report_len = max_offset;
+ }
+
+ ts->usage_table_populated = true;
+
+ return max_report_len;
+}
+
+static int axiom_discover(struct axiom_data *ts)
+{
+ int error;
+
+ /*
+ * Fetch the first page of usage u31 to get the
+ * device information and the number of usages
+ */
+ error = axiom_read(ts, AXIOM_DEVINFO_USAGE_ID, 0, &ts->devinfo, AXIOM_U31_PAGE0_LENGTH);
+ if (error)
+ return error;
+
+ dev_dbg(ts->dev, " Boot Mode : %s\n",
+ FIELD_GET(AXIOM_U31_BOOTMODE_MASK,
+ le16_to_cpu(ts->devinfo.device_id)) ? "BLP" : "TCP");
+ dev_dbg(ts->dev, " Device ID : %04lx\n",
+ FIELD_GET(AXIOM_U31_DEVID_MASK, le16_to_cpu(ts->devinfo.device_id)));
+ dev_dbg(ts->dev, " Firmware Rev : %02x.%02x\n", ts->devinfo.fw_major,
+ ts->devinfo.fw_minor);
+ dev_dbg(ts->dev, " Bootloader Rev : %02x.%02x\n", ts->devinfo.bootloader_fw_major,
+ ts->devinfo.bootloader_fw_minor);
+ dev_dbg(ts->dev, " FW Extra Info : %04x\n", ts->devinfo.fw_info_extra);
+ dev_dbg(ts->dev, " Silicon : %04x\n", le16_to_cpu(ts->devinfo.jedec_id));
+ dev_dbg(ts->dev, " Number usages : %04x\n", ts->devinfo.num_usages);
+
+ ts->max_report_len = axiom_populate_usage_table(ts);
+ if (!ts->max_report_len || !ts->devinfo.num_usages ||
+ ts->max_report_len > AXIOM_MAX_REPORT_LEN) {
+ dev_err(ts->dev, "Invalid report length or usages number");
+ return -EINVAL;
+ }
+
+ dev_dbg(ts->dev, "Max Report Length: %u\n", ts->max_report_len);
+
+ return 0;
+}
+
+/*
+ * Support function to axiom_process_u41_report.
+ * Generates input-subsystem events for every target.
+ * After calling this function the caller shall issue
+ * a Sync to the input sub-system.
+ */
+static bool axiom_process_u41_report_target(struct axiom_data *ts,
+ struct axiom_target_report *target)
+{
+ struct input_dev *input_dev = ts->input_dev;
+ struct axiom_u41_target *target_prev_state;
+ enum axiom_target_state current_state;
+ int id;
+
+ /* Verify the target index */
+ if (target->index >= AXIOM_U41_MAX_TARGETS) {
+ dev_err(ts->dev, "Invalid target index! %u\n", target->index);
+ return false;
+ }
+
+ target_prev_state = &ts->targets[target->index];
+
+ current_state = AXIOM_TARGET_STATE_NOT_PRESENT;
+
+ if (target->present) {
+ if (target->z >= 0)
+ current_state = AXIOM_TARGET_STATE_TOUCHING;
+ else if (target->z > AXIOM_PROX_LEVEL && target->z < 0)
+ current_state = AXIOM_TARGET_STATE_HOVER;
+ else if (target->z == AXIOM_PROX_LEVEL)
+ current_state = AXIOM_TARGET_STATE_PROX;
+ }
+
+ if (target_prev_state->state == current_state &&
+ target_prev_state->x == target->x &&
+ target_prev_state->y == target->y &&
+ target_prev_state->z == target->z)
+ return false;
+
+ id = target->index;
+
+ dev_dbg(ts->dev, "U41 Target T%u, present:%u, x:%u, y:%u, z:%d\n",
+ target->index, target->present,
+ target->x, target->y, target->z);
+
+ switch (current_state) {
+ case AXIOM_TARGET_STATE_NOT_PRESENT:
+ case AXIOM_TARGET_STATE_PROX:
+ if (!target_prev_state->insert)
+ break;
+ target_prev_state->insert = false;
+
+ if (!id)
+ input_report_key(input_dev, BTN_TOUCH, 0);
+
+ input_mt_report_slot_inactive(input_dev);
+ /*
+ * make sure the previous coordinates are
+ * all off screen when the finger comes back
+ */
+ target->x = 65535;
+ target->y = 65535;
+ target->z = AXIOM_PROX_LEVEL;
+ break;
+ case AXIOM_TARGET_STATE_HOVER:
+ case AXIOM_TARGET_STATE_TOUCHING:
+ target_prev_state->insert = true;
+ input_report_abs(input_dev, ABS_MT_TRACKING_ID, id);
+ input_report_abs(input_dev, ABS_MT_POSITION_X, target->x);
+ input_report_abs(input_dev, ABS_MT_POSITION_Y, target->y);
+
+ if (current_state == AXIOM_TARGET_STATE_TOUCHING) {
+ input_report_abs(input_dev, ABS_MT_DISTANCE, 0);
+ input_report_abs(input_dev, ABS_DISTANCE, 0);
+ input_report_abs(input_dev, ABS_MT_PRESSURE, target->z);
+ input_report_abs(input_dev, ABS_PRESSURE, target->z);
+ } else {
+ input_report_abs(input_dev, ABS_MT_DISTANCE, -target->z);
+ input_report_abs(input_dev, ABS_DISTANCE, -target->z);
+ input_report_abs(input_dev, ABS_MT_PRESSURE, 0);
+ input_report_abs(input_dev, ABS_PRESSURE, 0);
+ }
+
+ if (!id)
+ input_report_key(input_dev, BTN_TOUCH, (current_state ==
+ AXIOM_TARGET_STATE_TOUCHING));
+ break;
+ default:
+ break;
+ }
+
+ target_prev_state->state = current_state;
+ target_prev_state->x = target->x;
+ target_prev_state->y = target->y;
+ target_prev_state->z = target->z;
+
+ return true;
+}
+
+/*
+ * U41 is the output report of the 2D CTS and contains the status of targets
+ * (including contacts and pre-contacts) along with their X,Y,Z values.
+ * When a target has been removed (no longer detected),
+ * the corresponding X,Y,Z values will be zeroed.
+ */
+static bool axiom_process_u41_report(struct axiom_data *ts, u8 *rx_buf)
+{
+ struct axiom_target_report target;
+ bool update_done = false;
+ u16 target_status;
+ int i;
+
+ target_status = get_unaligned_le16(rx_buf + 1);
+
+ for (i = 0; i < AXIOM_U41_MAX_TARGETS; i++) {
+ u8 *target_step = &rx_buf[i * 4];
+
+ target.index = i;
+ input_mt_slot(ts->input_dev, i);
+ input_mt_report_slot_state(ts->input_dev, MT_TOOL_FINGER, true);
+ target.present = ((target_status & (1 << i)) != 0) ? 1 : 0;
+ target.x = get_unaligned_le16(target_step + 3);
+ target.y = get_unaligned_le16(target_step + 5);
+ target.z = (s8)(rx_buf[i + 43]);
+ touchscreen_report_pos(ts->input_dev, &ts->prop, target.x, target.y, true);
+ update_done |= axiom_process_u41_report_target(ts, &target);
+ }
+
+ return update_done;
+}
+
+/*
+ * U46 report contains a low level measurement data generated by the capacitive
+ * displacement sensor (CDS) algorithms from the auxiliary channels.
+ * This information is useful when tuning multi-press to assess mechanical
+ * consistency in the unit's construction.
+ */
+static void axiom_process_u46_report(struct axiom_data *ts, u8 *rx_buf)
+{
+ struct input_dev *input_dev = ts->input_dev;
+ u32 event_value;
+ u16 aux_value;
+ int i;
+
+ for (i = 0; i < AXIOM_U46_AUX_CHANNELS; i++) {
+ u8 *target_step = &rx_buf[i * 2];
+
+ input_mt_slot(input_dev, i);
+ input_mt_report_slot_state(input_dev, MT_TOOL_FINGER, true);
+ aux_value = get_unaligned_le16(target_step + 1) & AXIOM_U46_AUX_MASK;
+ event_value = (i << 16) | (aux_value);
+ input_event(input_dev, EV_MSC, MSC_RAW, event_value);
+ }
+}
+
+/*
+ * Validates the crc and demultiplexes the axiom reports to the appropriate
+ * report handler
+ */
+static int axiom_handle_events(struct axiom_data *ts)
+{
+ struct input_dev *input_dev = ts->input_dev;
+ u8 *report_data = ts->rx_buf;
+ struct device *dev = ts->dev;
+ u16 crc_report;
+ u8 *crc_bytes;
+ u16 crc_calc;
+ int error;
+ u8 len;
+
+ error = axiom_read(ts, AXIOM_REPORT_USAGE_ID, 0, report_data, ts->max_report_len);
+ if (error)
+ return error;
+
+ len = (report_data[0] & AXIOM_COMMS_REPORT_LEN_MASK) << 1;
+ if (len <= 2) {
+ dev_err(dev, "Zero length report discarded.\n");
+ return -ENODATA;
+ }
+
+ /* Validate the report CRC */
+ crc_bytes = &report_data[len];
+
+ crc_report = get_unaligned_le16(crc_bytes - 2);
+ /* Length is in 16 bit words and remove the size of the CRC16 itself */
+ crc_calc = crc16(0, report_data, (len - 2));
+
+ if (crc_calc != crc_report) {
+ dev_err(dev,
+ "CRC mismatch! Expected: %#x, Calculated CRC: %#x.\n",
+ crc_report, crc_calc);
+ return -EINVAL;
+ }
+
+ switch (report_data[1]) {
+ case AXIOM_USAGE_2DCTS_REPORT_ID:
+ if (axiom_process_u41_report(ts, &report_data[1])) {
+ input_mt_sync_frame(input_dev);
+ input_sync(input_dev);
+ }
+ break;
+
+ case AXIOM_USAGE_2AUX_REPORT_ID:
+ /* This is an aux report (force) */
+ axiom_process_u46_report(ts, &report_data[1]);
+ input_mt_sync(input_dev);
+ input_sync(input_dev);
+ break;
+
+ case AXIOM_USAGE_2HB_REPORT_ID:
+ /* This is a heartbeat report */
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static void axiom_i2c_poll(struct input_dev *input_dev)
+{
+ struct axiom_data *ts = input_get_drvdata(input_dev);
+
+ axiom_handle_events(ts);
+}
+
+static irqreturn_t axiom_irq(int irq, void *dev_id)
+{
+ struct axiom_data *ts = dev_id;
+
+ axiom_handle_events(ts);
+
+ return IRQ_HANDLED;
+}
+
+static void axiom_reset(struct gpio_desc *reset_gpio)
+{
+ gpiod_set_value_cansleep(reset_gpio, 1);
+ usleep_range(1000, 2000);
+ gpiod_set_value_cansleep(reset_gpio, 0);
+ msleep(AXIOM_STARTUP_TIME_MS);
+}
+
+static int axiom_i2c_probe(struct i2c_client *client)
+{
+ struct device *dev = &client->dev;
+ struct input_dev *input_dev;
+ struct axiom_data *ts;
+ u32 poll_interval;
+ int target;
+ int error;
+
+ ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
+ if (!ts)
+ return -ENOMEM;
+
+ i2c_set_clientdata(client, ts);
+ ts->client = client;
+ ts->dev = dev;
+
+ ts->regmap = devm_regmap_init_i2c(client, &axiom_i2c_regmap_config);
+ error = PTR_ERR_OR_ZERO(ts->regmap);
+ if (error) {
+ dev_err(dev, "Failed to initialize regmap: %d\n", error);
+ return error;
+ }
+
+ ts->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
+ if (IS_ERR(ts->reset_gpio))
+ return dev_err_probe(dev, PTR_ERR(ts->reset_gpio), "failed to get reset GPIO\n");
+
+ if (ts->reset_gpio)
+ axiom_reset(ts->reset_gpio);
+
+ ts->vddi = devm_regulator_get_optional(dev, "vddi");
+ if (!IS_ERR(ts->vddi)) {
+ error = devm_regulator_get_enable(dev, "vddi");
+ if (error)
+ return dev_err_probe(&client->dev, error,
+ "Failed to enable vddi regulator\n");
+ }
+
+ ts->vdda = devm_regulator_get_optional(dev, "vdda");
+ if (!IS_ERR(ts->vdda)) {
+ error = devm_regulator_get_enable(dev, "vdda");
+ if (error)
+ return dev_err_probe(&client->dev, error,
+ "Failed to enable vdda regulator\n");
+ msleep(AXIOM_STARTUP_TIME_MS);
+ }
+
+ error = axiom_discover(ts);
+ if (error)
+ return dev_err_probe(dev, error, "Failed touchscreen discover\n");
+
+ input_dev = devm_input_allocate_device(ts->dev);
+ if (!input_dev)
+ return -ENOMEM;
+
+ input_dev->name = "TouchNetix axiom Touchscreen";
+ input_dev->phys = "input/axiom_ts";
+
+ input_set_abs_params(input_dev, ABS_MT_POSITION_X, 0, 65535, 0, 0);
+ input_set_abs_params(input_dev, ABS_MT_POSITION_Y, 0, 65535, 0, 0);
+ input_set_abs_params(input_dev, ABS_MT_TOOL_TYPE, 0, MT_TOOL_MAX, 0, 0);
+ input_set_abs_params(input_dev, ABS_MT_DISTANCE, 0, 127, 0, 0);
+ input_set_abs_params(input_dev, ABS_MT_PRESSURE, 0, 127, 0, 0);
+
+ touchscreen_parse_properties(input_dev, true, &ts->prop);
+
+ /* Registers the axiom device as a touchscreen instead of a mouse pointer */
+ error = input_mt_init_slots(input_dev, AXIOM_U41_MAX_TARGETS, INPUT_MT_DIRECT);
+ if (error)
+ return error;
+
+ /* Enables the raw data for up to 4 force channels to be sent to the input subsystem */
+ set_bit(EV_REL, input_dev->evbit);
+ set_bit(EV_MSC, input_dev->evbit);
+ /* Declare that we support "RAW" Miscellaneous events */
+ set_bit(MSC_RAW, input_dev->mscbit);
+
+ ts->input_dev = input_dev;
+ input_set_drvdata(ts->input_dev, ts);
+
+ /* Ensure that all reports are initialised to not be present. */
+ for (target = 0; target < AXIOM_U41_MAX_TARGETS; target++)
+ ts->targets[target].state = AXIOM_TARGET_STATE_NOT_PRESENT;
+
+ error = devm_request_threaded_irq(dev, client->irq, NULL,
+ axiom_irq, IRQF_ONESHOT, dev_name(dev), ts);
+ if (error) {
+ dev_info(dev, "Request irq failed, falling back to polling mode");
+
+ error = input_setup_polling(input_dev, axiom_i2c_poll);
+ if (error)
+ return dev_err_probe(ts->dev, error, "Unable to set up polling mode\n");
+
+ if (!device_property_read_u32(ts->dev, "poll-interval", &poll_interval))
+ input_set_poll_interval(input_dev, poll_interval);
+ else
+ input_set_poll_interval(input_dev, POLL_INTERVAL_DEFAULT_MS);
+ }
+
+ error = input_register_device(input_dev);
+ if (error)
+ return dev_err_probe(ts->dev, error,
+ "Could not register with Input Sub-system.\n");
+
+ return 0;
+}
+
+static const struct i2c_device_id axiom_i2c_id_table[] = {
+ { "ax54a" },
+ { },
+};
+MODULE_DEVICE_TABLE(i2c, axiom_i2c_id_table);
+
+static const struct of_device_id axiom_i2c_of_match[] = {
+ { .compatible = "touchnetix,ax54a", },
+ { }
+};
+MODULE_DEVICE_TABLE(of, axiom_i2c_of_match);
+
+static struct i2c_driver axiom_i2c_driver = {
+ .driver = {
+ .name = "axiom",
+ .of_match_table = axiom_i2c_of_match,
+ },
+ .id_table = axiom_i2c_id_table,
+ .probe = axiom_i2c_probe,
+};
+module_i2c_driver(axiom_i2c_driver);
+
+MODULE_AUTHOR("Bart Prescott <[email protected]>");
+MODULE_AUTHOR("Pedro Torruella <[email protected]>");
+MODULE_AUTHOR("Mark Satterthwaite <[email protected]>");
+MODULE_AUTHOR("Hannah Rossiter <[email protected]>");
+MODULE_AUTHOR("Kamel Bouhara <[email protected]>");
+MODULE_DESCRIPTION("TouchNetix axiom touchscreen I2C bus driver");
+MODULE_LICENSE("GPL");
--
2.25.1
Hi Kamel,
please see below, be aware that this is just an rough review.
On 24-03-01, Kamel Bouhara wrote:
> Add a new driver for the TouchNetix's axiom family of
> touchscreen controllers. This driver only supports i2c
> and can be later adapted for SPI and USB support.
>
> Signed-off-by: Kamel Bouhara <[email protected]>
> ---
> MAINTAINERS | 1 +
> drivers/input/touchscreen/Kconfig | 12 +
> drivers/input/touchscreen/Makefile | 1 +
> drivers/input/touchscreen/touchnetix_axiom.c | 669 +++++++++++++++++++
> 4 files changed, 683 insertions(+)
> create mode 100644 drivers/input/touchscreen/touchnetix_axiom.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 4b3ed2f22b89..de5fad8f317a 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -22262,6 +22262,7 @@ M: Kamel Bouhara <[email protected]>
> L: [email protected]
> S: Maintained
> F: Documentation/devicetree/bindings/input/touchscreen/touchnetix,ax54a.yaml
> +F: drivers/input/touchscreen/touchnetix_axiom.c
>
> TPM DEVICE DRIVER
> M: Peter Huewe <[email protected]>
> diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
> index e3e2324547b9..f36bee8d8696 100644
> --- a/drivers/input/touchscreen/Kconfig
> +++ b/drivers/input/touchscreen/Kconfig
> @@ -803,6 +803,18 @@ config TOUCHSCREEN_MIGOR
> To compile this driver as a module, choose M here: the
> module will be called migor_ts.
>
> +config TOUCHSCREEN_TOUCHNETIX_AXIOM
> + tristate "TouchNetix AXIOM based touchscreen controllers"
> + depends on I2C
> + help
> + Say Y here if you have a axiom touchscreen connected to
> + your system.
> +
> + If unsure, say N.
> +
> + To compile this driver as a module, choose M here: the
> + module will be called axiom.
> +
> config TOUCHSCREEN_TOUCHRIGHT
> tristate "Touchright serial touchscreen"
> select SERIO
> diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
> index 62bd24f3ac8e..8e32a2df5e18 100644
> --- a/drivers/input/touchscreen/Makefile
> +++ b/drivers/input/touchscreen/Makefile
> @@ -88,6 +88,7 @@ obj-$(CONFIG_TOUCHSCREEN_SUR40) += sur40.o
> obj-$(CONFIG_TOUCHSCREEN_SURFACE3_SPI) += surface3_spi.o
> obj-$(CONFIG_TOUCHSCREEN_TI_AM335X_TSC) += ti_am335x_tsc.o
> obj-$(CONFIG_TOUCHSCREEN_TOUCHIT213) += touchit213.o
> +obj-$(CONFIG_TOUCHSCREEN_TOUCHNETIX_AXIOM) += touchnetix_axiom.o
> obj-$(CONFIG_TOUCHSCREEN_TOUCHRIGHT) += touchright.o
> obj-$(CONFIG_TOUCHSCREEN_TOUCHWIN) += touchwin.o
> obj-$(CONFIG_TOUCHSCREEN_TS4800) += ts4800-ts.o
> diff --git a/drivers/input/touchscreen/touchnetix_axiom.c b/drivers/input/touchscreen/touchnetix_axiom.c
> new file mode 100644
> index 000000000000..e7abba41eed0
> --- /dev/null
> +++ b/drivers/input/touchscreen/touchnetix_axiom.c
> @@ -0,0 +1,669 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * TouchNetix axiom Touchscreen Driver
> + *
> + * Copyright (C) 2020-2023 TouchNetix Ltd.
> + *
> + * Author(s): Bart Prescott <[email protected]>
> + * Pedro Torruella <[email protected]>
> + * Mark Satterthwaite <[email protected]>
> + * Hannah Rossiter <[email protected]>
> + * Kamel Bouhara <[email protected]>
> + *
> + */
> +#include <linux/bitfield.h>
> +#include <linux/crc16.h>
> +#include <linux/delay.h>
> +#include <linux/device.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/mod_devicetable.h>
> +#include <linux/regmap.h>
> +
> +#include <asm/unaligned.h>
> +#define AXIOM_PROX_LEVEL -128
> +#define AXIOM_DMA_OPS_DELAY_USEC 250
> +#define AXIOM_STARTUP_TIME_MS 110
> +/*
> + * Register group u31 has 2 pages for usage table entries.
> + */
> +#define AXIOM_U31_MAX_USAGES 0xff
> +#define AXIOM_U31_BYTES_PER_USAGE 6
> +#define AXIOM_U31_PAGE0_LENGTH 0x0C
> +#define AXIOM_U31_BOOTMODE_MASK BIT(7)
> +#define AXIOM_U31_DEVID_MASK GENMASK(14, 0)
> +
> +#define AXIOM_MAX_REPORT_LEN 0x7f
> +
> +#define AXIOM_CMD_HEADER_READ_MASK BIT(15)
> +#define AXIOM_U41_MAX_TARGETS 10
> +
> +#define AXIOM_U46_AUX_CHANNELS 4
> +#define AXIOM_U46_AUX_MASK GENMASK(11, 0)
> +
> +#define AXIOM_COMMS_MAX_USAGE_PAGES 3
> +#define AXIOM_COMMS_PAGE_SIZE 256
> +#define AXIOM_COMMS_REPORT_LEN_MASK GENMASK(6, 0)
> +
> +#define AXIOM_REPORT_USAGE_ID 0x34
> +#define AXIOM_DEVINFO_USAGE_ID 0x31
> +#define AXIOM_USAGE_2HB_REPORT_ID 0x01
> +#define AXIOM_USAGE_2AUX_REPORT_ID 0x46
> +#define AXIOM_USAGE_2DCTS_REPORT_ID 0x41
> +
> +#define AXIOM_PAGE_OFFSET_MASK GENMASK(6, 0)
> +
> +struct axiom_devinfo {
> + __le16 device_id;
> + u8 fw_minor;
> + u8 fw_major;
> + u8 fw_info_extra;
> + u8 tcp_revision;
> + u8 bootloader_fw_minor;
> + u8 bootloader_fw_major;
> + __le16 jedec_id;
> + u8 num_usages;
> +} __packed;
> +
> +/*
> + * Describes parameters of a specific usage, essentially a single element of
> + * the "Usage Table"
> + */
> +struct axiom_usage_entry {
> + u8 id;
> + u8 is_report;
> + u8 start_page;
> + u8 num_pages;
> +};
> +
> +/*
> + * Represents state of a touch or target when detected prior to a touch (eg.
> + * hover or proximity events).
> + */
> +enum axiom_target_state {
> + AXIOM_TARGET_STATE_NOT_PRESENT = 0,
> + AXIOM_TARGET_STATE_PROX = 1,
> + AXIOM_TARGET_STATE_HOVER = 2,
> + AXIOM_TARGET_STATE_TOUCHING = 3,
> +};
> +
> +struct axiom_u41_target {
> + enum axiom_target_state state;
> + u16 x;
> + u16 y;
> + s8 z;
> + bool insert;
> + bool touch;
> +};
> +
> +struct axiom_target_report {
> + u8 index;
> + u8 present;
> + u16 x;
> + u16 y;
> + s8 z;
> +};
> +
> +struct axiom_cmd_header {
> + __le16 target_address;
> + __le16 length;
> +} __packed;
> +
> +struct axiom_data {
> + struct axiom_devinfo devinfo;
> + struct device *dev;
> + struct gpio_desc *reset_gpio;
> + struct i2c_client *client;
> + struct input_dev *input_dev;
> + u32 max_report_len;
> + u8 rx_buf[AXIOM_COMMS_MAX_USAGE_PAGES * AXIOM_COMMS_PAGE_SIZE];
> + struct axiom_u41_target targets[AXIOM_U41_MAX_TARGETS];
> + struct axiom_usage_entry usage_table[AXIOM_U31_MAX_USAGES];
> + bool usage_table_populated;
> + struct regulator *vdda;
> + struct regulator *vddi;
> + struct regmap *regmap;
> + struct touchscreen_properties prop;
> +};
> +
> +static const struct regmap_config axiom_i2c_regmap_config = {
> + .reg_bits = 32,
> + .reg_format_endian = REGMAP_ENDIAN_LITTLE,
> + .val_bits = 8,
> + .val_format_endian = REGMAP_ENDIAN_LITTLE,
> +};
> +
> +/*
> + * axiom devices are typically configured to report touches at a rate
> + * of 100Hz (10ms) for systems that require polling for reports.
> + * When reports are polled, it will be expected to occasionally
> + * observe the overflow bit being set in the reports.
> + * This indicates that reports are not being read fast enough.
> + */
> +#define POLL_INTERVAL_DEFAULT_MS 10
> +
> +/* Translate usage/page/offset triplet into physical address. */
> +static u16 axiom_usage_to_target_address(struct axiom_data *ts, u8 usage, u8 page,
> + char offset)
> +{
> + /* At the moment the convention is that u31 is always at physical address 0x0 */
> + if (!ts->usage_table_populated) {
> + if (usage == AXIOM_DEVINFO_USAGE_ID)
> + return ((page << 8) + offset);
> + else
> + return 0xffff;
> + }
> +
> + if (page >= ts->usage_table[usage].num_pages) {
> + dev_err(ts->dev, "Invalid usage table! usage: u%02x, page: %02x, offset: %02x\n",
> + usage, page, offset);
> + return 0xffff;
> + }
> +
> + return ((ts->usage_table[usage].start_page + page) << 8) + offset;
> +}
> +
> +static int axiom_read(struct axiom_data *ts, u8 usage, u8 page, void *buf, u16 len)
> +{
> + struct axiom_cmd_header cmd_header;
> + u32 preamble;
> + int ret;
> +
> + cmd_header.target_address = cpu_to_le16(axiom_usage_to_target_address(ts, usage, page, 0));
> + cmd_header.length = cpu_to_le16(len | AXIOM_CMD_HEADER_READ_MASK);
> +
> + preamble = get_unaligned_le32(&cmd_header);
> +
> + ret = regmap_write(ts->regmap, preamble, 0);
> + if (ret) {
> + dev_err(ts->dev, "failed to write preamble, error %d\n", ret);
> + return ret;
> + }
> +
> + ret = regmap_raw_read(ts->regmap, 0, buf, len);
> + if (ret) {
> + dev_err(ts->dev, "failed to read target address %04x, error %d\n",
> + cmd_header.target_address, ret);
> + return ret;
> + }
> +
> + /* Wait device's DMA operations */
> + usleep_range(AXIOM_DMA_OPS_DELAY_USEC, AXIOM_DMA_OPS_DELAY_USEC + 50);
> +
> + return 0;
> +}
> +
> +/*
> + * One of the main purposes for reading the usage table is to identify
> + * which usages reside at which target address.
> + * When performing subsequent reads or writes to AXIOM, the target address
> + * is used to specify which usage is being accessed.
> + * Consider the following discovery code which will build up the usage table.
> + */
> +static u32 axiom_populate_usage_table(struct axiom_data *ts)
> +{
> + struct axiom_usage_entry *usage_table;
> + u8 *rx_data = ts->rx_buf;
> + u32 max_report_len = 0;
> + u32 usage_id;
> + int error;
> +
> + usage_table = ts->usage_table;
> +
> + /* Read the second page of usage u31 to get the usage table */
> + error = axiom_read(ts, AXIOM_DEVINFO_USAGE_ID, 1, rx_data,
> + (AXIOM_U31_BYTES_PER_USAGE * ts->devinfo.num_usages));
> +
> + if (error)
> + return error;
> +
> + for (usage_id = 0; usage_id < ts->devinfo.num_usages; usage_id++) {
> + u16 offset = (usage_id * AXIOM_U31_BYTES_PER_USAGE);
> + u8 id = rx_data[offset + 0];
> + u8 start_page = rx_data[offset + 1];
> + u8 num_pages = rx_data[offset + 2];
> + u32 max_offset = ((rx_data[offset + 3] & AXIOM_PAGE_OFFSET_MASK) + 1) * 2;
> +
> + usage_table[id].is_report = !num_pages;
> +
> + /* Store the entry into the usage table */
> + usage_table[id].id = id;
> + usage_table[id].start_page = start_page;
> + usage_table[id].num_pages = num_pages;
> +
> + dev_dbg(ts->dev, "Usage u%02x Info: %*ph\n", id, AXIOM_U31_BYTES_PER_USAGE,
> + &rx_data[offset]);
> +
> + /* Identify the max report length the module will receive */
> + if (usage_table[id].is_report && max_offset > max_report_len)
> + max_report_len = max_offset;
> + }
> +
> + ts->usage_table_populated = true;
> +
> + return max_report_len;
> +}
> +
> +static int axiom_discover(struct axiom_data *ts)
> +{
> + int error;
> +
> + /*
> + * Fetch the first page of usage u31 to get the
> + * device information and the number of usages
> + */
> + error = axiom_read(ts, AXIOM_DEVINFO_USAGE_ID, 0, &ts->devinfo, AXIOM_U31_PAGE0_LENGTH);
> + if (error)
> + return error;
> +
> + dev_dbg(ts->dev, " Boot Mode : %s\n",
> + FIELD_GET(AXIOM_U31_BOOTMODE_MASK,
> + le16_to_cpu(ts->devinfo.device_id)) ? "BLP" : "TCP");
> + dev_dbg(ts->dev, " Device ID : %04lx\n",
> + FIELD_GET(AXIOM_U31_DEVID_MASK, le16_to_cpu(ts->devinfo.device_id)));
> + dev_dbg(ts->dev, " Firmware Rev : %02x.%02x\n", ts->devinfo.fw_major,
> + ts->devinfo.fw_minor);
> + dev_dbg(ts->dev, " Bootloader Rev : %02x.%02x\n", ts->devinfo.bootloader_fw_major,
> + ts->devinfo.bootloader_fw_minor);
> + dev_dbg(ts->dev, " FW Extra Info : %04x\n", ts->devinfo.fw_info_extra);
> + dev_dbg(ts->dev, " Silicon : %04x\n", le16_to_cpu(ts->devinfo.jedec_id));
> + dev_dbg(ts->dev, " Number usages : %04x\n", ts->devinfo.num_usages);
> +
> + ts->max_report_len = axiom_populate_usage_table(ts);
> + if (!ts->max_report_len || !ts->devinfo.num_usages ||
> + ts->max_report_len > AXIOM_MAX_REPORT_LEN) {
> + dev_err(ts->dev, "Invalid report length or usages number");
> + return -EINVAL;
> + }
> +
> + dev_dbg(ts->dev, "Max Report Length: %u\n", ts->max_report_len);
> +
> + return 0;
> +}
> +
> +/*
> + * Support function to axiom_process_u41_report.
> + * Generates input-subsystem events for every target.
> + * After calling this function the caller shall issue
> + * a Sync to the input sub-system.
> + */
> +static bool axiom_process_u41_report_target(struct axiom_data *ts,
> + struct axiom_target_report *target)
> +{
> + struct input_dev *input_dev = ts->input_dev;
> + struct axiom_u41_target *target_prev_state;
> + enum axiom_target_state current_state;
> + int id;
> +
> + /* Verify the target index */
> + if (target->index >= AXIOM_U41_MAX_TARGETS) {
> + dev_err(ts->dev, "Invalid target index! %u\n", target->index);
> + return false;
> + }
> +
> + target_prev_state = &ts->targets[target->index];
> +
> + current_state = AXIOM_TARGET_STATE_NOT_PRESENT;
> +
> + if (target->present) {
> + if (target->z >= 0)
> + current_state = AXIOM_TARGET_STATE_TOUCHING;
> + else if (target->z > AXIOM_PROX_LEVEL && target->z < 0)
> + current_state = AXIOM_TARGET_STATE_HOVER;
> + else if (target->z == AXIOM_PROX_LEVEL)
> + current_state = AXIOM_TARGET_STATE_PROX;
> + }
> +
> + if (target_prev_state->state == current_state &&
> + target_prev_state->x == target->x &&
> + target_prev_state->y == target->y &&
> + target_prev_state->z == target->z)
> + return false;
> +
> + id = target->index;
> +
> + dev_dbg(ts->dev, "U41 Target T%u, present:%u, x:%u, y:%u, z:%d\n",
> + target->index, target->present,
> + target->x, target->y, target->z);
> +
> + switch (current_state) {
> + case AXIOM_TARGET_STATE_NOT_PRESENT:
> + case AXIOM_TARGET_STATE_PROX:
> + if (!target_prev_state->insert)
> + break;
> + target_prev_state->insert = false;
> +
> + if (!id)
> + input_report_key(input_dev, BTN_TOUCH, 0);
> +
> + input_mt_report_slot_inactive(input_dev);
> + /*
> + * make sure the previous coordinates are
> + * all off screen when the finger comes back
> + */
> + target->x = 65535;
> + target->y = 65535;
> + target->z = AXIOM_PROX_LEVEL;
> + break;
> + case AXIOM_TARGET_STATE_HOVER:
> + case AXIOM_TARGET_STATE_TOUCHING:
> + target_prev_state->insert = true;
> + input_report_abs(input_dev, ABS_MT_TRACKING_ID, id);
> + input_report_abs(input_dev, ABS_MT_POSITION_X, target->x);
> + input_report_abs(input_dev, ABS_MT_POSITION_Y, target->y);
> +
> + if (current_state == AXIOM_TARGET_STATE_TOUCHING) {
> + input_report_abs(input_dev, ABS_MT_DISTANCE, 0);
> + input_report_abs(input_dev, ABS_DISTANCE, 0);
> + input_report_abs(input_dev, ABS_MT_PRESSURE, target->z);
> + input_report_abs(input_dev, ABS_PRESSURE, target->z);
> + } else {
> + input_report_abs(input_dev, ABS_MT_DISTANCE, -target->z);
> + input_report_abs(input_dev, ABS_DISTANCE, -target->z);
> + input_report_abs(input_dev, ABS_MT_PRESSURE, 0);
> + input_report_abs(input_dev, ABS_PRESSURE, 0);
> + }
> +
> + if (!id)
> + input_report_key(input_dev, BTN_TOUCH, (current_state ==
> + AXIOM_TARGET_STATE_TOUCHING));
> + break;
> + default:
> + break;
> + }
> +
> + target_prev_state->state = current_state;
> + target_prev_state->x = target->x;
> + target_prev_state->y = target->y;
> + target_prev_state->z = target->z;
> +
> + return true;
> +}
> +
> +/*
> + * U41 is the output report of the 2D CTS and contains the status of targets
> + * (including contacts and pre-contacts) along with their X,Y,Z values.
> + * When a target has been removed (no longer detected),
> + * the corresponding X,Y,Z values will be zeroed.
> + */
> +static bool axiom_process_u41_report(struct axiom_data *ts, u8 *rx_buf)
> +{
> + struct axiom_target_report target;
> + bool update_done = false;
> + u16 target_status;
> + int i;
> +
> + target_status = get_unaligned_le16(rx_buf + 1);
> +
> + for (i = 0; i < AXIOM_U41_MAX_TARGETS; i++) {
> + u8 *target_step = &rx_buf[i * 4];
> +
> + target.index = i;
> + input_mt_slot(ts->input_dev, i);
> + input_mt_report_slot_state(ts->input_dev, MT_TOOL_FINGER, true);
> + target.present = ((target_status & (1 << i)) != 0) ? 1 : 0;
> + target.x = get_unaligned_le16(target_step + 3);
> + target.y = get_unaligned_le16(target_step + 5);
> + target.z = (s8)(rx_buf[i + 43]);
> + touchscreen_report_pos(ts->input_dev, &ts->prop, target.x, target.y, true);
> + update_done |= axiom_process_u41_report_target(ts, &target);
> + }
> +
> + return update_done;
> +}
> +
> +/*
> + * U46 report contains a low level measurement data generated by the capacitive
> + * displacement sensor (CDS) algorithms from the auxiliary channels.
> + * This information is useful when tuning multi-press to assess mechanical
> + * consistency in the unit's construction.
> + */
> +static void axiom_process_u46_report(struct axiom_data *ts, u8 *rx_buf)
> +{
> + struct input_dev *input_dev = ts->input_dev;
> + u32 event_value;
> + u16 aux_value;
> + int i;
> +
> + for (i = 0; i < AXIOM_U46_AUX_CHANNELS; i++) {
> + u8 *target_step = &rx_buf[i * 2];
> +
> + input_mt_slot(input_dev, i);
> + input_mt_report_slot_state(input_dev, MT_TOOL_FINGER, true);
> + aux_value = get_unaligned_le16(target_step + 1) & AXIOM_U46_AUX_MASK;
> + event_value = (i << 16) | (aux_value);
> + input_event(input_dev, EV_MSC, MSC_RAW, event_value);
> + }
> +}
> +
> +/*
> + * Validates the crc and demultiplexes the axiom reports to the appropriate
> + * report handler
> + */
> +static int axiom_handle_events(struct axiom_data *ts)
> +{
> + struct input_dev *input_dev = ts->input_dev;
> + u8 *report_data = ts->rx_buf;
> + struct device *dev = ts->dev;
> + u16 crc_report;
> + u8 *crc_bytes;
> + u16 crc_calc;
> + int error;
> + u8 len;
> +
> + error = axiom_read(ts, AXIOM_REPORT_USAGE_ID, 0, report_data, ts->max_report_len);
> + if (error)
> + return error;
> +
> + len = (report_data[0] & AXIOM_COMMS_REPORT_LEN_MASK) << 1;
> + if (len <= 2) {
> + dev_err(dev, "Zero length report discarded.\n");
> + return -ENODATA;
> + }
> +
> + /* Validate the report CRC */
> + crc_bytes = &report_data[len];
> +
> + crc_report = get_unaligned_le16(crc_bytes - 2);
> + /* Length is in 16 bit words and remove the size of the CRC16 itself */
> + crc_calc = crc16(0, report_data, (len - 2));
> +
> + if (crc_calc != crc_report) {
> + dev_err(dev,
> + "CRC mismatch! Expected: %#x, Calculated CRC: %#x.\n",
> + crc_report, crc_calc);
> + return -EINVAL;
> + }
> +
> + switch (report_data[1]) {
> + case AXIOM_USAGE_2DCTS_REPORT_ID:
> + if (axiom_process_u41_report(ts, &report_data[1])) {
> + input_mt_sync_frame(input_dev);
> + input_sync(input_dev);
> + }
> + break;
> +
> + case AXIOM_USAGE_2AUX_REPORT_ID:
> + /* This is an aux report (force) */
> + axiom_process_u46_report(ts, &report_data[1]);
> + input_mt_sync(input_dev);
> + input_sync(input_dev);
> + break;
> +
> + case AXIOM_USAGE_2HB_REPORT_ID:
> + /* This is a heartbeat report */
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + return 0;
> +}
> +
> +static void axiom_i2c_poll(struct input_dev *input_dev)
> +{
> + struct axiom_data *ts = input_get_drvdata(input_dev);
> +
> + axiom_handle_events(ts);
> +}
> +
> +static irqreturn_t axiom_irq(int irq, void *dev_id)
> +{
> + struct axiom_data *ts = dev_id;
> +
> + axiom_handle_events(ts);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static void axiom_reset(struct gpio_desc *reset_gpio)
> +{
> + gpiod_set_value_cansleep(reset_gpio, 1);
> + usleep_range(1000, 2000);
> + gpiod_set_value_cansleep(reset_gpio, 0);
> + msleep(AXIOM_STARTUP_TIME_MS);
> +}
> +
> +static int axiom_i2c_probe(struct i2c_client *client)
> +{
> + struct device *dev = &client->dev;
> + struct input_dev *input_dev;
> + struct axiom_data *ts;
> + u32 poll_interval;
> + int target;
> + int error;
> +
> + ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
> + if (!ts)
> + return -ENOMEM;
> +
> + i2c_set_clientdata(client, ts);
> + ts->client = client;
> + ts->dev = dev;
> +
> + ts->regmap = devm_regmap_init_i2c(client, &axiom_i2c_regmap_config);
> + error = PTR_ERR_OR_ZERO(ts->regmap);
> + if (error) {
> + dev_err(dev, "Failed to initialize regmap: %d\n", error);
> + return error;
> + }
> +
> + ts->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
> + if (IS_ERR(ts->reset_gpio))
> + return dev_err_probe(dev, PTR_ERR(ts->reset_gpio), "failed to get reset GPIO\n");
> +
> + if (ts->reset_gpio)
> + axiom_reset(ts->reset_gpio);
This seems useless, since you doing an reset without enabling the power
supply (below). I know there are systems which do have the supply always
connected or for ACPI the supply is managed via firmware, but the driver
should implement the correct logic and for DT/OF case this is not
correct.
> +
> + ts->vddi = devm_regulator_get_optional(dev, "vddi");
> + if (!IS_ERR(ts->vddi)) {
> + error = devm_regulator_get_enable(dev, "vddi");
Regulators are ref counted and now you request the regulator twice. Also
the regulator is not optional, it is required for the device to work.
Same applies to the vdda below.
> + if (error)
> + return dev_err_probe(&client->dev, error,
> + "Failed to enable vddi regulator\n");
> + }
> +
> + ts->vdda = devm_regulator_get_optional(dev, "vdda");
> + if (!IS_ERR(ts->vdda)) {
> + error = devm_regulator_get_enable(dev, "vdda");
> + if (error)
> + return dev_err_probe(&client->dev, error,
> + "Failed to enable vdda regulator\n");
> + msleep(AXIOM_STARTUP_TIME_MS);
> + }
> +
> + error = axiom_discover(ts);
> + if (error)
> + return dev_err_probe(dev, error, "Failed touchscreen discover\n");
> +
> + input_dev = devm_input_allocate_device(ts->dev);
> + if (!input_dev)
> + return -ENOMEM;
> +
> + input_dev->name = "TouchNetix axiom Touchscreen";
> + input_dev->phys = "input/axiom_ts";
> +
> + input_set_abs_params(input_dev, ABS_MT_POSITION_X, 0, 65535, 0, 0);
> + input_set_abs_params(input_dev, ABS_MT_POSITION_Y, 0, 65535, 0, 0);
> + input_set_abs_params(input_dev, ABS_MT_TOOL_TYPE, 0, MT_TOOL_MAX, 0, 0);
> + input_set_abs_params(input_dev, ABS_MT_DISTANCE, 0, 127, 0, 0);
> + input_set_abs_params(input_dev, ABS_MT_PRESSURE, 0, 127, 0, 0);
> +
> + touchscreen_parse_properties(input_dev, true, &ts->prop);
> +
> + /* Registers the axiom device as a touchscreen instead of a mouse pointer */
> + error = input_mt_init_slots(input_dev, AXIOM_U41_MAX_TARGETS, INPUT_MT_DIRECT);
> + if (error)
> + return error;
> +
> + /* Enables the raw data for up to 4 force channels to be sent to the input subsystem */
> + set_bit(EV_REL, input_dev->evbit);
> + set_bit(EV_MSC, input_dev->evbit);
> + /* Declare that we support "RAW" Miscellaneous events */
> + set_bit(MSC_RAW, input_dev->mscbit);
> +
> + ts->input_dev = input_dev;
> + input_set_drvdata(ts->input_dev, ts);
> +
> + /* Ensure that all reports are initialised to not be present. */
> + for (target = 0; target < AXIOM_U41_MAX_TARGETS; target++)
> + ts->targets[target].state = AXIOM_TARGET_STATE_NOT_PRESENT;
> +
> + error = devm_request_threaded_irq(dev, client->irq, NULL,
> + axiom_irq, IRQF_ONESHOT, dev_name(dev), ts);
> + if (error) {
> + dev_info(dev, "Request irq failed, falling back to polling mode");
> +
> + error = input_setup_polling(input_dev, axiom_i2c_poll);
> + if (error)
> + return dev_err_probe(ts->dev, error, "Unable to set up polling mode\n");
> +
> + if (!device_property_read_u32(ts->dev, "poll-interval", &poll_interval))
This is not wrong but can we move the "poll-intervall" parsing into
touchscreen_parse_properties() since it seems pretty common to me.
> + input_set_poll_interval(input_dev, poll_interval);
> + else
> + input_set_poll_interval(input_dev, POLL_INTERVAL_DEFAULT_MS);
> + }
> +
> + error = input_register_device(input_dev);
> + if (error)
> + return dev_err_probe(ts->dev, error,
> + "Could not register with Input Sub-system.\n");
return input_register_device(input_dev);
> +
> + return 0;
> +}
> +
> +static const struct i2c_device_id axiom_i2c_id_table[] = {
> + { "ax54a" },
> + { },
> +};
> +MODULE_DEVICE_TABLE(i2c, axiom_i2c_id_table);
Do we really need an i2c-id table here? Most platforms do either use OF
or ACPI.
Regards,
Marco
> +static const struct of_device_id axiom_i2c_of_match[] = {
> + { .compatible = "touchnetix,ax54a", },
> + { }
> +};
> +MODULE_DEVICE_TABLE(of, axiom_i2c_of_match);
> +
> +static struct i2c_driver axiom_i2c_driver = {
> + .driver = {
> + .name = "axiom",
> + .of_match_table = axiom_i2c_of_match,
> + },
> + .id_table = axiom_i2c_id_table,
> + .probe = axiom_i2c_probe,
> +};
> +module_i2c_driver(axiom_i2c_driver);
> +
> +MODULE_AUTHOR("Bart Prescott <[email protected]>");
> +MODULE_AUTHOR("Pedro Torruella <[email protected]>");
> +MODULE_AUTHOR("Mark Satterthwaite <[email protected]>");
> +MODULE_AUTHOR("Hannah Rossiter <[email protected]>");
> +MODULE_AUTHOR("Kamel Bouhara <[email protected]>");
> +MODULE_DESCRIPTION("TouchNetix axiom touchscreen I2C bus driver");
> +MODULE_LICENSE("GPL");
> --
> 2.25.1
>
>
Le Wed, Mar 13, 2024 at 09:21:35PM +0100, Marco Felsch a ?crit :
> Hi Kamel,
>
Hi Marco,
> please see below, be aware that this is just an rough review.
>
[...]
> > +
> > +static int axiom_i2c_probe(struct i2c_client *client)
> > +{
> > + struct device *dev = &client->dev;
> > + struct input_dev *input_dev;
> > + struct axiom_data *ts;
> > + u32 poll_interval;
> > + int target;
> > + int error;
> > +
> > + ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
> > + if (!ts)
> > + return -ENOMEM;
> > +
> > + i2c_set_clientdata(client, ts);
> > + ts->client = client;
> > + ts->dev = dev;
> > +
> > + ts->regmap = devm_regmap_init_i2c(client, &axiom_i2c_regmap_config);
> > + error = PTR_ERR_OR_ZERO(ts->regmap);
> > + if (error) {
> > + dev_err(dev, "Failed to initialize regmap: %d\n", error);
> > + return error;
> > + }
> > +
> > + ts->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
> > + if (IS_ERR(ts->reset_gpio))
> > + return dev_err_probe(dev, PTR_ERR(ts->reset_gpio), "failed to get reset GPIO\n");
> > +
> > + if (ts->reset_gpio)
> > + axiom_reset(ts->reset_gpio);
>
> This seems useless, since you doing an reset without enabling the power
> supply (below). I know there are systems which do have the supply always
> connected or for ACPI the supply is managed via firmware, but the driver
> should implement the correct logic and for DT/OF case this is not
> correct.
>
Alright, this can be moved after enabling vdda regulator as this is
still required in the power sequence.
> > +
> > + ts->vddi = devm_regulator_get_optional(dev, "vddi");
> > + if (!IS_ERR(ts->vddi)) {
> > + error = devm_regulator_get_enable(dev, "vddi");
>
> Regulators are ref counted and now you request the regulator twice. Also
> the regulator is not optional, it is required for the device to work.
> Same applies to the vdda below.
>
Ack, I wrongly took my use case (ACPI + fixed regulators) but this isn't
a common use case.
> > + if (error)
> > + return dev_err_probe(&client->dev, error,
> > + "Failed to enable vddi regulator\n");
> > + }
> > +
> > + ts->vdda = devm_regulator_get_optional(dev, "vdda");
> > + if (!IS_ERR(ts->vdda)) {
> > + error = devm_regulator_get_enable(dev, "vdda");
> > + if (error)
> > + return dev_err_probe(&client->dev, error,
> > + "Failed to enable vdda regulator\n");
> > + msleep(AXIOM_STARTUP_TIME_MS);
> > + }
> > +
> > + error = axiom_discover(ts);
> > + if (error)
> > + return dev_err_probe(dev, error, "Failed touchscreen discover\n");
> > +
> > + input_dev = devm_input_allocate_device(ts->dev);
> > + if (!input_dev)
> > + return -ENOMEM;
> > +
> > + input_dev->name = "TouchNetix axiom Touchscreen";
> > + input_dev->phys = "input/axiom_ts";
> > +
> > + input_set_abs_params(input_dev, ABS_MT_POSITION_X, 0, 65535, 0, 0);
> > + input_set_abs_params(input_dev, ABS_MT_POSITION_Y, 0, 65535, 0, 0);
> > + input_set_abs_params(input_dev, ABS_MT_TOOL_TYPE, 0, MT_TOOL_MAX, 0, 0);
> > + input_set_abs_params(input_dev, ABS_MT_DISTANCE, 0, 127, 0, 0);
> > + input_set_abs_params(input_dev, ABS_MT_PRESSURE, 0, 127, 0, 0);
> > +
> > + touchscreen_parse_properties(input_dev, true, &ts->prop);
> > +
> > + /* Registers the axiom device as a touchscreen instead of a mouse pointer */
> > + error = input_mt_init_slots(input_dev, AXIOM_U41_MAX_TARGETS, INPUT_MT_DIRECT);
> > + if (error)
> > + return error;
> > +
> > + /* Enables the raw data for up to 4 force channels to be sent to the input subsystem */
> > + set_bit(EV_REL, input_dev->evbit);
> > + set_bit(EV_MSC, input_dev->evbit);
> > + /* Declare that we support "RAW" Miscellaneous events */
> > + set_bit(MSC_RAW, input_dev->mscbit);
> > +
> > + ts->input_dev = input_dev;
> > + input_set_drvdata(ts->input_dev, ts);
> > +
> > + /* Ensure that all reports are initialised to not be present. */
> > + for (target = 0; target < AXIOM_U41_MAX_TARGETS; target++)
> > + ts->targets[target].state = AXIOM_TARGET_STATE_NOT_PRESENT;
> > +
> > + error = devm_request_threaded_irq(dev, client->irq, NULL,
> > + axiom_irq, IRQF_ONESHOT, dev_name(dev), ts);
> > + if (error) {
> > + dev_info(dev, "Request irq failed, falling back to polling mode");
> > +
> > + error = input_setup_polling(input_dev, axiom_i2c_poll);
> > + if (error)
> > + return dev_err_probe(ts->dev, error, "Unable to set up polling mode\n");
> > +
> > + if (!device_property_read_u32(ts->dev, "poll-interval", &poll_interval))
>
> This is not wrong but can we move the "poll-intervall" parsing into
> touchscreen_parse_properties() since it seems pretty common to me.
Maybe too late to add it in this series :).
>
> > + input_set_poll_interval(input_dev, poll_interval);
> > + else
> > + input_set_poll_interval(input_dev, POLL_INTERVAL_DEFAULT_MS);
> > + }
> > +
> > + error = input_register_device(input_dev);
> > + if (error)
> > + return dev_err_probe(ts->dev, error,
> > + "Could not register with Input Sub-system.\n");
>
> return input_register_device(input_dev);
Ack, thanks.
>
> > +
> > + return 0;
> > +}
> > +
> > +static const struct i2c_device_id axiom_i2c_id_table[] = {
> > + { "ax54a" },
> > + { },
> > +};
> > +MODULE_DEVICE_TABLE(i2c, axiom_i2c_id_table);
>
> Do we really need an i2c-id table here? Most platforms do either use OF
> or ACPI.
If not wrong this is used to enumarate the device from userspace
and in my case it is required as there is no direct i2c controller
exposed from ACPI pov.
Thanks !
--
Kamel Bouhara, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com
On 24-03-14, Kamel Bouhara wrote:
> Le Wed, Mar 13, 2024 at 09:21:35PM +0100, Marco Felsch a ?crit :
> > Hi Kamel,
> >
> Hi Marco,
>
> > please see below, be aware that this is just an rough review.
> >
>
> [...]
>
> > > +
> > > +static int axiom_i2c_probe(struct i2c_client *client)
> > > +{
> > > + struct device *dev = &client->dev;
> > > + struct input_dev *input_dev;
> > > + struct axiom_data *ts;
> > > + u32 poll_interval;
> > > + int target;
> > > + int error;
> > > +
> > > + ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
> > > + if (!ts)
> > > + return -ENOMEM;
> > > +
> > > + i2c_set_clientdata(client, ts);
> > > + ts->client = client;
> > > + ts->dev = dev;
> > > +
> > > + ts->regmap = devm_regmap_init_i2c(client, &axiom_i2c_regmap_config);
> > > + error = PTR_ERR_OR_ZERO(ts->regmap);
> > > + if (error) {
> > > + dev_err(dev, "Failed to initialize regmap: %d\n", error);
> > > + return error;
> > > + }
> > > +
> > > + ts->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
> > > + if (IS_ERR(ts->reset_gpio))
> > > + return dev_err_probe(dev, PTR_ERR(ts->reset_gpio), "failed to get reset GPIO\n");
> > > +
> > > + if (ts->reset_gpio)
> > > + axiom_reset(ts->reset_gpio);
> >
> > This seems useless, since you doing an reset without enabling the power
> > supply (below). I know there are systems which do have the supply always
> > connected or for ACPI the supply is managed via firmware, but the driver
> > should implement the correct logic and for DT/OF case this is not
> > correct.
> >
>
> Alright, this can be moved after enabling vdda regulator as this is
> still required in the power sequence.
>
> > > +
> > > + ts->vddi = devm_regulator_get_optional(dev, "vddi");
> > > + if (!IS_ERR(ts->vddi)) {
> > > + error = devm_regulator_get_enable(dev, "vddi");
> >
> > Regulators are ref counted and now you request the regulator twice. Also
> > the regulator is not optional, it is required for the device to work.
> > Same applies to the vdda below.
> >
>
> Ack, I wrongly took my use case (ACPI + fixed regulators) but this isn't
> a common use case.
>
> > > + if (error)
> > > + return dev_err_probe(&client->dev, error,
> > > + "Failed to enable vddi regulator\n");
> > > + }
> > > +
> > > + ts->vdda = devm_regulator_get_optional(dev, "vdda");
> > > + if (!IS_ERR(ts->vdda)) {
> > > + error = devm_regulator_get_enable(dev, "vdda");
> > > + if (error)
> > > + return dev_err_probe(&client->dev, error,
> > > + "Failed to enable vdda regulator\n");
> > > + msleep(AXIOM_STARTUP_TIME_MS);
> > > + }
> > > +
> > > + error = axiom_discover(ts);
> > > + if (error)
> > > + return dev_err_probe(dev, error, "Failed touchscreen discover\n");
> > > +
> > > + input_dev = devm_input_allocate_device(ts->dev);
> > > + if (!input_dev)
> > > + return -ENOMEM;
> > > +
> > > + input_dev->name = "TouchNetix axiom Touchscreen";
> > > + input_dev->phys = "input/axiom_ts";
> > > +
> > > + input_set_abs_params(input_dev, ABS_MT_POSITION_X, 0, 65535, 0, 0);
> > > + input_set_abs_params(input_dev, ABS_MT_POSITION_Y, 0, 65535, 0, 0);
> > > + input_set_abs_params(input_dev, ABS_MT_TOOL_TYPE, 0, MT_TOOL_MAX, 0, 0);
> > > + input_set_abs_params(input_dev, ABS_MT_DISTANCE, 0, 127, 0, 0);
> > > + input_set_abs_params(input_dev, ABS_MT_PRESSURE, 0, 127, 0, 0);
> > > +
> > > + touchscreen_parse_properties(input_dev, true, &ts->prop);
> > > +
> > > + /* Registers the axiom device as a touchscreen instead of a mouse pointer */
> > > + error = input_mt_init_slots(input_dev, AXIOM_U41_MAX_TARGETS, INPUT_MT_DIRECT);
> > > + if (error)
> > > + return error;
> > > +
> > > + /* Enables the raw data for up to 4 force channels to be sent to the input subsystem */
> > > + set_bit(EV_REL, input_dev->evbit);
> > > + set_bit(EV_MSC, input_dev->evbit);
> > > + /* Declare that we support "RAW" Miscellaneous events */
> > > + set_bit(MSC_RAW, input_dev->mscbit);
> > > +
> > > + ts->input_dev = input_dev;
> > > + input_set_drvdata(ts->input_dev, ts);
> > > +
> > > + /* Ensure that all reports are initialised to not be present. */
> > > + for (target = 0; target < AXIOM_U41_MAX_TARGETS; target++)
> > > + ts->targets[target].state = AXIOM_TARGET_STATE_NOT_PRESENT;
> > > +
> > > + error = devm_request_threaded_irq(dev, client->irq, NULL,
> > > + axiom_irq, IRQF_ONESHOT, dev_name(dev), ts);
> > > + if (error) {
> > > + dev_info(dev, "Request irq failed, falling back to polling mode");
> > > +
> > > + error = input_setup_polling(input_dev, axiom_i2c_poll);
> > > + if (error)
> > > + return dev_err_probe(ts->dev, error, "Unable to set up polling mode\n");
> > > +
> > > + if (!device_property_read_u32(ts->dev, "poll-interval", &poll_interval))
> >
> > This is not wrong but can we move the "poll-intervall" parsing into
> > touchscreen_parse_properties() since it seems pretty common to me.
>
> Maybe too late to add it in this series :).
>
> >
> > > + input_set_poll_interval(input_dev, poll_interval);
> > > + else
> > > + input_set_poll_interval(input_dev, POLL_INTERVAL_DEFAULT_MS);
> > > + }
> > > +
> > > + error = input_register_device(input_dev);
> > > + if (error)
> > > + return dev_err_probe(ts->dev, error,
> > > + "Could not register with Input Sub-system.\n");
> >
> > return input_register_device(input_dev);
>
> Ack, thanks.
>
> >
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +static const struct i2c_device_id axiom_i2c_id_table[] = {
> > > + { "ax54a" },
> > > + { },
> > > +};
> > > +MODULE_DEVICE_TABLE(i2c, axiom_i2c_id_table);
> >
> > Do we really need an i2c-id table here? Most platforms do either use OF
> > or ACPI.
>
> If not wrong this is used to enumarate the device from userspace
> and in my case it is required as there is no direct i2c controller
> exposed from ACPI pov.
Ah you're right, I forgot this use-case.
Regards,
Marco
>
> Thanks !
>
> --
> Kamel Bouhara, Bootlin
> Embedded Linux and kernel engineering
> https://bootlin.com
>
Le Wed, Mar 13, 2024 at 09:21:35PM +0100, Marco Felsch a ?crit :
> Hi Kamel,
>
Hello Marco,
[...]
> > +static int axiom_i2c_probe(struct i2c_client *client)
> > +{
> > + struct device *dev = &client->dev;
> > + struct input_dev *input_dev;
> > + struct axiom_data *ts;
> > + u32 poll_interval;
> > + int target;
> > + int error;
> > +
> > + ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
> > + if (!ts)
> > + return -ENOMEM;
> > +
> > + i2c_set_clientdata(client, ts);
> > + ts->client = client;
> > + ts->dev = dev;
> > +
> > + ts->regmap = devm_regmap_init_i2c(client, &axiom_i2c_regmap_config);
> > + error = PTR_ERR_OR_ZERO(ts->regmap);
> > + if (error) {
> > + dev_err(dev, "Failed to initialize regmap: %d\n", error);
> > + return error;
> > + }
> > +
> > + ts->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
> > + if (IS_ERR(ts->reset_gpio))
> > + return dev_err_probe(dev, PTR_ERR(ts->reset_gpio), "failed to get reset GPIO\n");
> > +
> > + if (ts->reset_gpio)
> > + axiom_reset(ts->reset_gpio);
>
> This seems useless, since you doing an reset without enabling the power
> supply (below). I know there are systems which do have the supply always
> connected or for ACPI the supply is managed via firmware, but the driver
> should implement the correct logic and for DT/OF case this is not
> correct.
>
> > +
> > + ts->vddi = devm_regulator_get_optional(dev, "vddi");
> > + if (!IS_ERR(ts->vddi)) {
> > + error = devm_regulator_get_enable(dev, "vddi");
>
> Regulators are ref counted and now you request the regulator twice. Also
> the regulator is not optional, it is required for the device to work.
> Same applies to the vdda below.
>
While it is true most of the time, it occurs that for x86 based boards,
adding a regulator entirely is not always possible.
In our particular case, the I2C controller for this touchscreen is
behind a CPLD (aka embedded controller) so I have no direct access to
the I2C controller and it isn't described in the ACPI table.
In a normal case, I would use ACPI override to pass regulator
properties, but here it's not possible.
Having a CPLD exposing this kind of controller is quite common on x86
based boards. So, we need a way to support the case when a regulator
can't be described. The optional regulator looked like a good option,
but if you have a better alternative, I am open to considering it.
--
Kamel Bouhara, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com
Le 2024-03-18 09:05, Kamel Bouhara a écrit :
> Le Wed, Mar 13, 2024 at 09:21:35PM +0100, Marco Felsch a écrit :
>> Hi Kamel,
>>
>
> Hello Marco,
>
> [...]
>
Hello,
>> > +static int axiom_i2c_probe(struct i2c_client *client)
>> > +{
>> > + struct device *dev = &client->dev;
>> > + struct input_dev *input_dev;
>> > + struct axiom_data *ts;
>> > + u32 poll_interval;
>> > + int target;
>> > + int error;
>> > +
>> > + ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
>> > + if (!ts)
>> > + return -ENOMEM;
>> > +
>> > + i2c_set_clientdata(client, ts);
>> > + ts->client = client;
>> > + ts->dev = dev;
>> > +
>> > + ts->regmap = devm_regmap_init_i2c(client, &axiom_i2c_regmap_config);
>> > + error = PTR_ERR_OR_ZERO(ts->regmap);
>> > + if (error) {
>> > + dev_err(dev, "Failed to initialize regmap: %d\n", error);
>> > + return error;
>> > + }
>> > +
>> > + ts->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
>> > + if (IS_ERR(ts->reset_gpio))
>> > + return dev_err_probe(dev, PTR_ERR(ts->reset_gpio), "failed to get reset GPIO\n");
>> > +
>> > + if (ts->reset_gpio)
>> > + axiom_reset(ts->reset_gpio);
>>
>> This seems useless, since you doing an reset without enabling the
>> power
>> supply (below). I know there are systems which do have the supply
>> always
>> connected or for ACPI the supply is managed via firmware, but the
>> driver
>> should implement the correct logic and for DT/OF case this is not
>> correct.
>>
>> > +
>> > + ts->vddi = devm_regulator_get_optional(dev, "vddi");
>> > + if (!IS_ERR(ts->vddi)) {
>> > + error = devm_regulator_get_enable(dev, "vddi");
>>
>> Regulators are ref counted and now you request the regulator twice.
>> Also
>> the regulator is not optional, it is required for the device to work.
>> Same applies to the vdda below.
>>
>
> While it is true most of the time, it occurs that for x86 based boards,
> adding a regulator entirely is not always possible.
>
> In our particular case, the I2C controller for this touchscreen is
> behind a CPLD (aka embedded controller) so I have no direct access to
> the I2C controller and it isn't described in the ACPI table.
>
> In a normal case, I would use ACPI override to pass regulator
> properties, but here it's not possible.
>
> Having a CPLD exposing this kind of controller is quite common on x86
> based boards. So, we need a way to support the case when a regulator
> can't be described. The optional regulator looked like a good option,
> but if you have a better alternative, I am open to considering it.
>
I actually confirmed this case is already handled in
acpi_subsystem_init():
...
» » /*
» » * If the system is using ACPI then we can be reasonably
» » * confident that any regulators are managed by the
firmware
» » * so tell the regulator core it has everything it needs
to
» » * know.
» » */
» » regulator_has_full_constraints();
Thanks Marco for the clue :) !
Regards,
--
Kamel Bouhara, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com