Input: adp5588-keys - export unused GPIO pins

This patch allows exporting GPIO pins not used by the keypad itself
to be accessible from elsewhere.

Signed-off-by: Xiaolong Chen <xiao-long.chen@motorola.com>
Signed-off-by: Yuanbo Ye <yuan-bo.ye@motorola.com>
Signed-off-by: Tao Hu <taohu@motorola.com>
Acked-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

2 files changed, 208 insertions, 2 deletions

diff --git a/drivers/input/keyboard/adp5588-keys.c b/drivers/input/keyboard/adp5588-keys.c
index 9096db73c3c8..c39ec93c0c58 100644
--- a/drivers/input/keyboard/adp5588-keys.c
+++ b/drivers/input/keyboard/adp5588-keys.c
@@ -19,6 +19,7 @@
 #include <linux/platform_device.h>
 #include <linux/input.h>
 #include <linux/i2c.h>
+#include <linux/gpio.h>
 #include <linux/slab.h>
 
 #include <linux/i2c/adp5588.h>
@@ -54,6 +55,10 @@
 
 #define KEYP_MAX_EVENT          10
 
+#define MAXGPIO                 18
+#define ADP_BANK(offs)          ((offs) >> 3)
+#define ADP_BIT(offs)           (1u << ((offs) & 0x7))
+
 /*
  * Early pre 4.0 Silicon required to delay readout by at least 25ms,
  * since the Event Counter Register updated 25ms after the interrupt
@@ -69,6 +74,14 @@ struct adp5588_kpad {
         unsigned short keycode[ADP5588_KEYMAPSIZE];
         const struct adp5588_gpi_map *gpimap;
         unsigned short gpimapsize;
+#ifdef CONFIG_GPIOLIB
+        unsigned char gpiomap[MAXGPIO];
+        bool export_gpio;
+        struct gpio_chip gc;
+        struct mutex gpio_lock; /* Protect cached dir, dat_out */
+        u8 dat_out[3];
+        u8 dir[3];
+#endif
 };
 
 static int adp5588_read(struct i2c_client *client, u8 reg)
@@ -86,6 +99,183 @@ static int adp5588_write(struct i2c_client *client, u8 reg, u8 val)
         return i2c_smbus_write_byte_data(client, reg, val);
 }
 
+#ifdef CONFIG_GPIOLIB
+static int adp5588_gpio_get_value(struct gpio_chip *chip, unsigned off)
+{
+        struct adp5588_kpad *kpad = container_of(chip, struct adp5588_kpad, gc);
+        unsigned int bank = ADP_BANK(kpad->gpiomap[off]);
+        unsigned int bit = ADP_BIT(kpad->gpiomap[off]);
+
+        return !!(adp5588_read(kpad->client, GPIO_DAT_STAT1 + bank) & bit);
+}
+
+static void adp5588_gpio_set_value(struct gpio_chip *chip,
+                                   unsigned off, int val)
+{
+        struct adp5588_kpad *kpad = container_of(chip, struct adp5588_kpad, gc);
+        unsigned int bank = ADP_BANK(kpad->gpiomap[off]);
+        unsigned int bit = ADP_BIT(kpad->gpiomap[off]);
+
+        mutex_lock(&kpad->gpio_lock);
+
+        if (val)
+                kpad->dat_out[bank] |= bit;
+        else
+                kpad->dat_out[bank] &= ~bit;
+
+        adp5588_write(kpad->client, GPIO_DAT_OUT1 + bank,
+                           kpad->dat_out[bank]);
+
+        mutex_unlock(&kpad->gpio_lock);
+}
+
+static int adp5588_gpio_direction_input(struct gpio_chip *chip, unsigned off)
+{
+        struct adp5588_kpad *kpad = container_of(chip, struct adp5588_kpad, gc);
+        unsigned int bank = ADP_BANK(kpad->gpiomap[off]);
+        unsigned int bit = ADP_BIT(kpad->gpiomap[off]);
+        int ret;
+
+        mutex_lock(&kpad->gpio_lock);
+
+        kpad->dir[bank] &= ~bit;
+        ret = adp5588_write(kpad->client, GPIO_DIR1 + bank, kpad->dir[bank]);
+
+        mutex_unlock(&kpad->gpio_lock);
+
+        return ret;
+}
+
+static int adp5588_gpio_direction_output(struct gpio_chip *chip,
+                                         unsigned off, int val)
+{
+        struct adp5588_kpad *kpad = container_of(chip, struct adp5588_kpad, gc);
+        unsigned int bank = ADP_BANK(kpad->gpiomap[off]);
+        unsigned int bit = ADP_BIT(kpad->gpiomap[off]);
+        int ret;
+
+        mutex_lock(&kpad->gpio_lock);
+
+        kpad->dir[bank] |= bit;
+
+        if (val)
+                kpad->dat_out[bank] |= bit;
+        else
+                kpad->dat_out[bank] &= ~bit;
+
+        ret = adp5588_write(kpad->client, GPIO_DAT_OUT1 + bank,
+                                 kpad->dat_out[bank]);
+        ret |= adp5588_write(kpad->client, GPIO_DIR1 + bank,
+                                 kpad->dir[bank]);
+
+        mutex_unlock(&kpad->gpio_lock);
+
+        return ret;
+}
+
+static int __devinit adp5588_gpio_add(struct device *dev)
+{
+        struct adp5588_kpad *kpad = dev_get_drvdata(dev);
+        const struct adp5588_kpad_platform_data *pdata = dev->platform_data;
+        const struct adp5588_gpio_platform_data *gpio_data = pdata->gpio_data;
+        int i, error;
+
+        if (gpio_data) {
+                int j = 0;
+                bool pin_used[MAXGPIO];
+
+                for (i = 0; i < pdata->rows; i++)
+                        pin_used[i] = true;
+
+                for (i = 0; i < pdata->cols; i++)
+                        pin_used[i + GPI_PIN_COL_BASE - GPI_PIN_BASE] = true;
+
+                for (i = 0; i < kpad->gpimapsize; i++)
+                        pin_used[kpad->gpimap[i].pin - GPI_PIN_BASE] = true;
+
+                for (i = 0; i < MAXGPIO; i++) {
+                        if (!pin_used[i])
+                                kpad->gpiomap[j++] = i;
+                }
+                kpad->gc.ngpio = j;
+
+                if (kpad->gc.ngpio)
+                        kpad->export_gpio = true;
+        }
+
+        if (!kpad->export_gpio) {
+                dev_info(dev, "No unused gpios left to export\n");
+                return 0;
+        }
+
+        kpad->gc.direction_input = adp5588_gpio_direction_input;
+        kpad->gc.direction_output = adp5588_gpio_direction_output;
+        kpad->gc.get = adp5588_gpio_get_value;
+        kpad->gc.set = adp5588_gpio_set_value;
+        kpad->gc.can_sleep = 1;
+
+        kpad->gc.base = gpio_data->gpio_start;
+        kpad->gc.label = kpad->client->name;
+        kpad->gc.owner = THIS_MODULE;
+
+        mutex_init(&kpad->gpio_lock);
+
+        error = gpiochip_add(&kpad->gc);
+        if (error) {
+                dev_err(dev, "gpiochip_add failed, err: %d\n", error);
+                return error;
+        }
+
+        for (i = 0; i <= ADP_BANK(MAXGPIO); i++) {
+                kpad->dat_out[i] = adp5588_read(kpad->client,
+                                                GPIO_DAT_OUT1 + i);
+                kpad->dir[i] = adp5588_read(kpad->client, GPIO_DIR1 + i);
+        }
+
+        if (gpio_data->setup) {
+                error = gpio_data->setup(kpad->client,
+                                         kpad->gc.base, kpad->gc.ngpio,
+                                         gpio_data->context);
+                if (error)