Input: add new driver for ARM CLPS711X keypad

This patch adds a new driver for keypad for Cirrus Logic CLPS711X CPUs.
Target CPU contain keyboard interface which can scan 8 column lines,
so we can read row GPIOs to read status and determine asserted state.

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

3 files changed, 220 insertions, 0 deletions

diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
index 935dcaf16646..76842d7dc2e3 100644
--- a/drivers/input/keyboard/Kconfig
+++ b/drivers/input/keyboard/Kconfig
@@ -151,6 +151,18 @@ config KEYBOARD_BFIN
           To compile this driver as a module, choose M here: the
           module will be called bf54x-keys.
 
+config KEYBOARD_CLPS711X
+        tristate "CLPS711X Keypad support"
+        depends on OF_GPIO && (ARCH_CLPS711X || COMPILE_TEST)
+        select INPUT_MATRIXKMAP
+        select INPUT_POLLDEV
+        help
+          Say Y here to enable the matrix keypad on the Cirrus Logic
+          CLPS711X CPUs.
+
+          To compile this driver as a module, choose M here: the
+          module will be called clps711x-keypad.
+
 config KEYBOARD_LKKBD
         tristate "DECstation/VAXstation LK201/LK401 keyboard"
         select SERIO
diff --git a/drivers/input/keyboard/Makefile b/drivers/input/keyboard/Makefile
index 81014d94a0c1..11cff7b84b47 100644
--- a/drivers/input/keyboard/Makefile
+++ b/drivers/input/keyboard/Makefile
@@ -11,6 +11,7 @@ obj-$(CONFIG_KEYBOARD_AMIGA)		+= amikbd.o
 obj-$(CONFIG_KEYBOARD_ATARI)            += atakbd.o
 obj-$(CONFIG_KEYBOARD_ATKBD)            += atkbd.o
 obj-$(CONFIG_KEYBOARD_BFIN)             += bf54x-keys.o
+obj-$(CONFIG_KEYBOARD_CLPS711X)         += clps711x-keypad.o
 obj-$(CONFIG_KEYBOARD_CROS_EC)          += cros_ec_keyb.o
 obj-$(CONFIG_KEYBOARD_DAVINCI)          += davinci_keyscan.o
 obj-$(CONFIG_KEYBOARD_EP93XX)           += ep93xx_keypad.o
diff --git a/drivers/input/keyboard/clps711x-keypad.c b/drivers/input/keyboard/clps711x-keypad.c
new file mode 100644
index 000000000000..3955aecee44b
--- /dev/null
+++ b/drivers/input/keyboard/clps711x-keypad.c
@@ -0,0 +1,207 @@
+/*
+ * Cirrus Logic CLPS711X Keypad driver
+ *
+ * Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/input.h>
+#include <linux/input-polldev.h>
+#include <linux/module.h>
+#include <linux/of_gpio.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/sched.h>
+#include <linux/input/matrix_keypad.h>
+#include <linux/mfd/syscon.h>
+#include <linux/mfd/syscon/clps711x.h>
+
+#define CLPS711X_KEYPAD_COL_COUNT       8
+
+struct clps711x_gpio_data {
+        struct gpio_desc *desc;
+        DECLARE_BITMAP(last_state, CLPS711X_KEYPAD_COL_COUNT);
+};
+
+struct clps711x_keypad_data {
+        struct regmap                   *syscon;
+        int                             row_count;
+        unsigned int                    row_shift;
+        struct clps711x_gpio_data       *gpio_data;
+};
+
+static void clps711x_keypad_poll(struct input_polled_dev *dev)
+{
+        const unsigned short *keycodes = dev->input->keycode;
+        struct clps711x_keypad_data *priv = dev->private;
+        bool sync = false;
+        int col, row;
+
+        for (col = 0; col < CLPS711X_KEYPAD_COL_COUNT; col++) {
+                /* Assert column */
+                regmap_update_bits(priv->syscon, SYSCON_OFFSET,
+                                   SYSCON1_KBDSCAN_MASK,
+                                   SYSCON1_KBDSCAN(8 + col));
+
+                /* Scan rows */
+                for (row = 0; row < priv->row_count; row++) {
+                        struct clps711x_gpio_data *data = &priv->gpio_data[row];
+                        bool state, state1;
+
+                        /* Read twice for protection against fluctuations */
+                        do {
+                                state = gpiod_get_value_cansleep(data->desc);
+                                cond_resched();
+                                state1 = gpiod_get_value_cansleep(data->desc);
+                        } while (state != state1);
+
+                        if (test_bit(col, data->last_state) != state) {
+                                int code = MATRIX_SCAN_CODE(row, col,
+                                                            priv->row_shift);
+
+                                if (state) {
+                                        set_bit(col, data->last_state);
+                                        input_event(dev->input, EV_MSC,
+                                                    MSC_SCAN, code);
+                                } else {
+                                        clear_bit(col, data->last_state);
+                                }
+
+                                if (keycodes[code])
+                                        input_report_key(dev->input,
+                                                         keycodes[code], state);
+                                sync = true;
+                        }
+                }
+
+                /* Set all columns to low */
+                regmap_update_bits(priv->syscon, SYSCON_OFFSET,
+                                   SYSCON1_KBDSCAN_MASK, SYSCON1_KBDSCAN(1));
+        }
+
+        if (sync)
+                input_sync(dev->input);
+}
+
+static int clps711x_keypad_probe(struct platform_device *pdev)
+{
+        struct clps711x_keypad_data *priv;
+        struct device *dev = &pdev->dev;
+        struct device_node *np = dev->of_node;
+        struct input_polled_dev *poll_dev;
+        u32 poll_interval;
+        int i, err;
+
+        priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+        if (!priv)
+                return -ENOMEM;
+
+        priv->syscon =
+                syscon_regmap_lookup_by_compatible("cirrus,clps711x-syscon1");
+        if (IS_ERR(priv->syscon))
+                return PTR_ERR(priv->syscon);
+
+        priv->row_count = of_gpio_named_count(np, "row-gpios");
+        if (priv->row_count < 1)
+                return -EINVAL;
+
+        priv->gpio_data = devm_kzalloc(dev,
+                                sizeof(*priv->gpio_data) * priv->row_count,
+                                GFP_KERNEL);
+        if (!priv->gpio_data)
+                return -ENOMEM;
+
+        priv->row_shift = get_count_order(CLPS711X_KEYPAD_COL_COUNT);
+
+        for (i = 0; i < priv->row_count; i++) {
+                struct clps711x_gpio_data *data = &priv->gpio_data[i];
+
+                data->desc = devm_gpiod_get_index(dev, "row", i);
+                if (!data->desc)
+                        return -EINVAL;
+
+                if (IS_ERR(data->desc))
+                        return PTR_ERR(data->desc);
+
+                gpiod_direction_input(data->desc);
+        }
+
+        err = of_property_read_u32(np, "poll-interval", &poll_interval);
+        if (err)
+                return err;
+
+        poll_dev = input_allocate_polled_device();
+        if (!poll_dev)
+                return -ENOMEM;
+
+        poll_dev->private               = priv;
+        poll_dev->poll                  = clps711x_keypad_poll;
+        poll_dev->poll_interval         = poll_interval;
+        poll_dev->input->name           = pdev->name;
+        poll_dev->input->dev.parent     = dev;
+        poll_dev->input->id.bustype     = BUS_HOST;
+        poll_dev->input->id.vendor      = 0x0001;
+        poll_dev->input->id.product     = 0x0001;
+        poll_dev->input->id.version     = 0x0100;
+
+        err = matrix_keypad_build_keymap(NULL, NULL, priv->row_count,
+                                         CLPS711X_KEYPAD_COL_COUNT,
+                                         NULL, poll_dev->input);
+        if (err)
+                goto out_err;
+
+        input_set_capability(poll_dev->input, EV_MSC, MSC_SCAN);
+        if (of_property_read_bool(np, "autorepeat"))
+                __set_bit(EV_REP, poll_dev->input->evbit);
+
+        platform_set_drvdata(pdev, poll_dev);
+
+        /* Set all columns to low */
+        regmap_update_bits(priv->syscon, SYSCON_OFFSET, SYSCON1_KBDSCAN_MASK,
+                           SYSCON1_KBDSCAN(1));
+
+        err = input_register_polled_device(poll_dev);
+        if (err)
+                goto out_err;
+
+        return 0;
+
+out_err:
+        input_free_polled_device(poll_dev);
+        return err;
+}
+
+static int clps711x_keypad_remove(struct platform_device *pdev)
+{
+        struct input_polled_dev *poll_dev = platform_get_drvdata(pdev);
+
+        input_unregister_polled_device(poll_dev);
+        input_free_polled_device(poll_dev);
+
+        return 0;
+}
+
+static struct of_device_id clps711x_keypad_of_match[] = {
+        { .compatible = "cirrus,clps711x-keypad", },
+        { }
+};
+MODULE_DEVICE_TABLE(of, clps711x_keypad_of_match);
+
+static struct platform_driver clps711x_keypad_driver = {
+        .driver = {
+                .name           = "clps711x-keypad",
+                .owner          = THIS_MODULE,
+                .of_match_table = clps711x_keypad_of_match,
+        },
+        .probe  = clps711x_keypad_probe,
+        .remove = clps711x_keypad_remove,
+};
+module_platform_driver(clps711x_keypad_driver);
+
+MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
+MODULE_DESCRIPTION("Cirrus Logic CLPS711X Keypad driver");
+MODULE_LICENSE("GPL");