@@ -9238,6 +9238,7 @@ M: Eddie James <eajames@linux.ibm.com>
L: linux-input@vger.kernel.org
S: Maintained
F: Documentation/devicetree/bindings/input/ibm,op-panel.yaml
+F: drivers/input/misc/ibm-panel.c
IBM Power 842 compression accelerator
M: Haren Myneni <haren@us.ibm.com>
@@ -730,6 +730,24 @@ config INPUT_ADXL34X_SPI
To compile this driver as a module, choose M here: the
module will be called adxl34x-spi.
+config INPUT_IBM_PANEL
+ tristate "IBM Operation Panel driver"
+ depends on I2C_SLAVE || COMPILE_TEST
+ help
+ Say Y here if you have an IBM Operation Panel connected to your system
+ over I2C. The panel is typically connected only to a system's service
+ processor (BMC).
+
+ If unsure, say N.
+
+ The Operation Panel is a controller with some buttons and an LCD
+ display that allows someone with physical access to the system to
+ perform various administrative tasks. This driver only supports the part
+ of the controller that sends commands to the system.
+
+ To compile this driver as a module, choose M here: the module will be
+ called ibm-panel.
+
config INPUT_IMS_PCU
tristate "IMS Passenger Control Unit driver"
depends on USB
@@ -41,6 +41,7 @@ obj-$(CONFIG_INPUT_GPIO_DECODER) += gpio_decoder.o
obj-$(CONFIG_INPUT_GPIO_VIBRA) += gpio-vibra.o
obj-$(CONFIG_INPUT_HISI_POWERKEY) += hisi_powerkey.o
obj-$(CONFIG_HP_SDC_RTC) += hp_sdc_rtc.o
+obj-$(CONFIG_INPUT_IBM_PANEL) += ibm-panel.o
obj-$(CONFIG_INPUT_IMS_PCU) += ims-pcu.o
obj-$(CONFIG_INPUT_IQS269A) += iqs269a.o
obj-$(CONFIG_INPUT_IQS626A) += iqs626a.o
new file mode 100644
@@ -0,0 +1,198 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) IBM Corporation 2020
+ */
+
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/input.h>
+#include <linux/kernel.h>
+#include <linux/limits.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/spinlock.h>
+
+#define DEVICE_NAME "ibm-panel"
+#define PANEL_KEYCODES_COUNT 3
+
+struct ibm_panel {
+ u8 idx;
+ u8 command[11];
+ u32 keycodes[PANEL_KEYCODES_COUNT];
+ spinlock_t lock; /* protects writes to idx and command */
+ struct input_dev *input;
+};
+
+static u8 ibm_panel_calculate_checksum(struct ibm_panel *panel)
+{
+ u8 chksum;
+ u16 sum = 0;
+ unsigned int i;
+
+ for (i = 0; i < sizeof(panel->command) - 1; ++i) {
+ sum += panel->command[i];
+ if (sum & 0xff00) {
+ sum &= 0xff;
+ sum++;
+ }
+ }
+
+ chksum = sum & 0xff;
+ chksum = ~chksum;
+ chksum++;
+
+ return chksum;
+}
+
+static void ibm_panel_process_command(struct ibm_panel *panel)
+{
+ u8 button;
+ u8 chksum;
+
+ if (panel->command[0] != 0xff && panel->command[1] != 0xf0) {
+ dev_dbg(&panel->input->dev, "command invalid: %02x %02x\n",
+ panel->command[0], panel->command[1]);
+ return;
+ }
+
+ chksum = ibm_panel_calculate_checksum(panel);
+ if (chksum != panel->command[sizeof(panel->command) - 1]) {
+ dev_dbg(&panel->input->dev,
+ "command failed checksum: %u != %u\n", chksum,
+ panel->command[sizeof(panel->command) - 1]);
+ return;
+ }
+
+ button = panel->command[2] & 0xf;
+ if (button < PANEL_KEYCODES_COUNT) {
+ input_report_key(panel->input, panel->keycodes[button],
+ !(panel->command[2] & 0x80));
+ input_sync(panel->input);
+ } else {
+ dev_dbg(&panel->input->dev, "unknown button %u\n",
+ button);
+ }
+}
+
+static int ibm_panel_i2c_slave_cb(struct i2c_client *client,
+ enum i2c_slave_event event, u8 *val)
+{
+ unsigned long flags;
+ struct ibm_panel *panel = i2c_get_clientdata(client);
+
+ dev_dbg(&panel->input->dev, "event: %u data: %02x\n", event, *val);
+
+ spin_lock_irqsave(&panel->lock, flags);
+
+ switch (event) {
+ case I2C_SLAVE_STOP:
+ if (panel->idx == sizeof(panel->command))
+ ibm_panel_process_command(panel);
+ else
+ dev_dbg(&panel->input->dev,
+ "command incorrect size %u\n", panel->idx);
+ fallthrough;
+ case I2C_SLAVE_WRITE_REQUESTED:
+ panel->idx = 0;
+ break;
+ case I2C_SLAVE_WRITE_RECEIVED:
+ if (panel->idx < sizeof(panel->command))
+ panel->command[panel->idx++] = *val;
+ else
+ /*
+ * The command is too long and therefore invalid, so set the index
+ * to it's largest possible value. When a STOP is finally received,
+ * the command will be rejected upon processing.
+ */
+ panel->idx = U8_MAX;
+ break;
+ case I2C_SLAVE_READ_REQUESTED:
+ case I2C_SLAVE_READ_PROCESSED:
+ *val = 0xff;
+ break;
+ default:
+ break;
+ }
+
+ spin_unlock_irqrestore(&panel->lock, flags);
+
+ return 0;
+}
+
+static int ibm_panel_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ int i;
+ int rc;
+ struct ibm_panel *panel = devm_kzalloc(&client->dev, sizeof(*panel),
+ GFP_KERNEL);
+
+ if (!panel)
+ return -ENOMEM;
+
+ panel->input = devm_input_allocate_device(&client->dev);
+ if (!panel->input)
+ return -ENOMEM;
+
+ panel->input->name = client->name;
+ panel->input->id.bustype = BUS_I2C;
+
+ rc = device_property_read_u32_array(&client->dev, "linux,keycodes",
+ panel->keycodes,
+ PANEL_KEYCODES_COUNT);
+ if (rc) {
+ /*
+ * Use gamepad buttons as defaults for compatibility with
+ * existing applications.
+ */
+ panel->keycodes[0] = BTN_NORTH;
+ panel->keycodes[1] = BTN_SOUTH;
+ panel->keycodes[2] = BTN_SELECT;
+ }
+
+ for (i = 0; i < PANEL_KEYCODES_COUNT; ++i)
+ input_set_capability(panel->input, EV_KEY, panel->keycodes[i]);
+
+ rc = input_register_device(panel->input);
+ if (rc) {
+ dev_err(&client->dev, "Failed to register input device: %d\n",
+ rc);
+ return rc;
+ }
+
+ spin_lock_init(&panel->lock);
+
+ i2c_set_clientdata(client, panel);
+ rc = i2c_slave_register(client, ibm_panel_i2c_slave_cb);
+ if (rc)
+ dev_err(&client->dev, "Failed to register as i2c slave: %d\n",
+ rc);
+
+ return rc;
+}
+
+static int ibm_panel_remove(struct i2c_client *client)
+{
+ i2c_slave_unregister(client);
+
+ return 0;
+}
+
+static const struct of_device_id ibm_panel_match[] = {
+ { .compatible = "ibm,op-panel" },
+ { }
+};
+
+static struct i2c_driver ibm_panel_driver = {
+ .driver = {
+ .name = DEVICE_NAME,
+ .of_match_table = ibm_panel_match,
+ },
+ .probe = ibm_panel_probe,
+ .remove = ibm_panel_remove,
+};
+module_i2c_driver(ibm_panel_driver);
+
+MODULE_AUTHOR("Eddie James <eajames@linux.ibm.com>");
+MODULE_DESCRIPTION("IBM Operation Panel Driver");
+MODULE_LICENSE("GPL");