[PATCH v2 4/4] input: misc: Add Gateworks System Controller support

From: Tim Harvey
Date: Mon Mar 05 2018 - 17:03:36 EST


Add support for dispatching Linux Input events for the various interrupts
the Gateworks System Controller provides.

Cc: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
Signed-off-by: Tim Harvey <tharvey@xxxxxxxxxxxxx>
---
v2:
- reword Kconfig
- revise license comment block
- remove unnecessary read of status register
- remove unnecessary setting of input->dev.parent
- use dt bindings for irq to keycode mapping
- add support for platform-data
- remove work-queue

drivers/input/misc/Kconfig | 9 ++
drivers/input/misc/Makefile | 1 +
drivers/input/misc/gsc-input.c | 180 ++++++++++++++++++++++++++++++++
include/linux/platform_data/gsc_input.h | 30 ++++++
4 files changed, 220 insertions(+)
create mode 100644 drivers/input/misc/gsc-input.c
create mode 100644 include/linux/platform_data/gsc_input.h

diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig
index 9f082a3..e05f4fe 100644
--- a/drivers/input/misc/Kconfig
+++ b/drivers/input/misc/Kconfig
@@ -117,6 +117,15 @@ config INPUT_E3X0_BUTTON
To compile this driver as a module, choose M here: the
module will be called e3x0_button.

+config INPUT_GSC
+ tristate "Gateworks System Controller input support"
+ depends on MFD_GSC
+ help
+ Support GSC events as Linux input events.
+
+ To compile this driver as a module, choose M here: the
+ module will be called gsc_input.
+
config INPUT_PCSPKR
tristate "PC Speaker support"
depends on PCSPKR_PLATFORM
diff --git a/drivers/input/misc/Makefile b/drivers/input/misc/Makefile
index 4b6118d..969debe 100644
--- a/drivers/input/misc/Makefile
+++ b/drivers/input/misc/Makefile
@@ -38,6 +38,7 @@ obj-$(CONFIG_INPUT_GP2A) += gp2ap002a00f.o
obj-$(CONFIG_INPUT_GPIO_BEEPER) += gpio-beeper.o
obj-$(CONFIG_INPUT_GPIO_TILT_POLLED) += gpio_tilt_polled.o
obj-$(CONFIG_INPUT_GPIO_DECODER) += gpio_decoder.o
+obj-$(CONFIG_INPUT_GSC) += gsc-input.o
obj-$(CONFIG_INPUT_HISI_POWERKEY) += hisi_powerkey.o
obj-$(CONFIG_HP_SDC_RTC) += hp_sdc_rtc.o
obj-$(CONFIG_INPUT_IMS_PCU) += ims-pcu.o
diff --git a/drivers/input/misc/gsc-input.c b/drivers/input/misc/gsc-input.c
new file mode 100644
index 0000000..27b5e93
--- /dev/null
+++ b/drivers/input/misc/gsc-input.c
@@ -0,0 +1,180 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * Copyright (C) 2018 Gateworks Corporation
+ *
+ * This driver dispatches Linux input events for GSC interrupt events
+ */
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#include <linux/mfd/gsc.h>
+#include <linux/platform_data/gsc_input.h>
+
+struct gsc_input_button_priv {
+ struct input_dev *input;
+ const struct gsc_input_button *button;
+};
+
+struct gsc_input_data {
+ struct gsc_dev *gsc;
+ struct gsc_input_platform_data *pdata;
+ struct input_dev *input;
+ struct gsc_input_button_priv *buttons;
+ int nbuttons;
+ unsigned int irqs[];
+#if 0
+ int irq;
+ struct work_struct irq_work;
+ struct mutex mutex;
+#endif
+};
+
+static irqreturn_t gsc_input_irq(int irq, void *data)
+{
+ const struct gsc_input_button_priv *button_priv = data;
+ struct input_dev *input = button_priv->input;
+
+ dev_dbg(&input->dev, "irq%d code=%d\n", irq, button_priv->button->code);
+ input_report_key(input, button_priv->button->code, 1);
+ input_sync(input);
+ input_report_key(input, button_priv->button->code, 0);
+ input_sync(input);
+
+ return IRQ_HANDLED;
+}
+
+static struct gsc_input_platform_data *
+gsc_input_get_devtree_pdata(struct device *dev)
+{
+ struct gsc_input_platform_data *pdata;
+ struct fwnode_handle *child;
+ struct gsc_input_button *button;
+ int nbuttons;
+
+ nbuttons = device_get_child_node_count(dev);
+ dev_dbg(dev, "buttons=%d\n", nbuttons);
+ if (nbuttons == 0)
+ return ERR_PTR(-ENODEV);
+
+ pdata = devm_kzalloc(dev,
+ sizeof(*pdata) + nbuttons * sizeof(*button),
+ GFP_KERNEL);
+ if (!pdata)
+ return ERR_PTR(-ENOMEM);
+
+ button = (struct gsc_input_button *)(pdata + 1);
+ pdata->buttons = button;
+ pdata->nbuttons = nbuttons;
+
+ device_property_read_string(dev, "label", &pdata->name);
+
+ device_for_each_child_node(dev, child) {
+ if (is_of_node(child))
+ button->irq = irq_of_parse_and_map(to_of_node(child),
+ 0);
+ if (fwnode_property_read_u32(child, "linux,code",
+ &button->code)) {
+ dev_err(dev, "Button without keycode\n");
+ fwnode_handle_put(child);
+ return ERR_PTR(-EINVAL);
+ }
+ fwnode_property_read_string(child, "label", &button->desc);
+ button++;
+ }
+
+ return pdata;
+}
+
+static int gsc_input_probe(struct platform_device *pdev)
+{
+ struct gsc_dev *gsc = dev_get_drvdata(pdev->dev.parent);
+ struct device *dev = &pdev->dev;
+ struct gsc_input_platform_data *pdata = dev_get_platdata(dev);
+ struct gsc_input_data *input;
+ int i, ret;
+
+ if (!pdata) {
+ pdata = gsc_input_get_devtree_pdata(dev);
+ if (IS_ERR(pdata))
+ return PTR_ERR(pdata);
+ }
+
+ input = devm_kzalloc(dev, sizeof(*input), GFP_KERNEL);
+ if (!input)
+ return -ENOMEM;
+ input->gsc = gsc;
+ input->pdata = pdata;
+
+ input->buttons = devm_kzalloc(dev, pdata->nbuttons *
+ sizeof(struct gsc_input_button_priv),
+ GFP_KERNEL);
+ if (!input->buttons)
+ return -ENOMEM;
+
+ /* Register input device */
+ input->input = devm_input_allocate_device(dev);
+ if (!input->input) {
+ dev_err(dev, "Can't allocate input device\n");
+ return -ENOMEM;
+ }
+ input->input->name = pdata->name ? : pdev->name;
+
+ platform_set_drvdata(pdev, gsc);
+
+ for (i = 0; i < pdata->nbuttons; i++) {
+ const struct gsc_input_button *button = &pdata->buttons[i];
+ struct gsc_input_button_priv *button_priv = &input->buttons[i];
+
+ button_priv = &input->buttons[i];
+ button_priv->button = &pdata->buttons[i];
+ button_priv->input = input->input;
+ input_set_capability(input->input, EV_KEY, button->code);
+
+ ret = devm_request_threaded_irq(dev, button->irq, NULL,
+ gsc_input_irq, 0,
+ button->desc,
+ button_priv);
+ if (ret) {
+ dev_err(dev, "irq%d request failed: %d\n)", button->irq,
+ ret);
+ return ret;
+ }
+ dev_dbg(dev, "button: irq%d/%d code=%d %s\n",
+ button->irq - pdata->buttons[0].irq,
+ button->irq,
+ button->code, button->desc);
+ }
+
+ ret = input_register_device(input->input);
+ if (ret < 0) {
+ dev_err(dev, "Can't register input device: %d\n", ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static const struct of_device_id gsc_input_dt_ids[] = {
+ { .compatible = "gw,gsc-input", },
+ {}
+};
+
+static struct platform_driver gsc_input_driver = {
+ .driver = {
+ .name = KBUILD_MODNAME,
+ .of_match_table = gsc_input_dt_ids,
+ },
+ .probe = gsc_input_probe,
+};
+
+module_platform_driver(gsc_input_driver);
+
+MODULE_AUTHOR("Tim Harvey <tharvey@xxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("GSC input driver");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/platform_data/gsc_input.h b/include/linux/platform_data/gsc_input.h
new file mode 100644
index 0000000..1a34284
--- /dev/null
+++ b/include/linux/platform_data/gsc_input.h
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _GSC_INPUT_H
+#define _GSC_INPUT_H
+
+/**
+ * struct gsc_input_button - configuration parameters
+ * @code: input event code (KEY_*, SW_*)
+ * @irq: irq index
+ * @desc: name of interrupt
+ */
+struct gsc_input_button {
+ unsigned int irq;
+ unsigned int code;
+ const char *desc;
+};
+
+/**
+ * struct gsc_input_platform_data - platform data for gsc_input driver
+ * @buttons: pointer to array of gsc_input_button structures
+ * describing buttons mapped to interrupt events
+ * @nbuttons: number of elements in @buttons array
+ * @name: input device name
+ */
+struct gsc_input_platform_data {
+ const struct gsc_input_button *buttons;
+ int nbuttons;
+ const char *name;
+};
+
+#endif
--
2.7.4