Input: ili210x - add ILI251X support

Add support for ILI251x touch controller. This controller is similar
to the ILI210x, except for the following differences:
- Does not support I2C R-W transfer, Read must be followed by an
  obscenely long delay, and then followed by Write
- Does support 10 simultaneous touch inputs.
- Touch data format is slightly different, pressure reporting does not
  work although the touch data contain such information.

Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

1 files changed, 103 insertions, 15 deletions

diff --git a/drivers/input/touchscreen/ili210x.c b/drivers/input/touchscreen/ili210x.c
index 4e550fe0cb15..6cfe463ac118 100644
--- a/drivers/input/touchscreen/ili210x.c
+++ b/drivers/input/touchscreen/ili210x.c
@@ -7,9 +7,11 @@
 #include <linux/delay.h>
 #include <linux/workqueue.h>
 #include <linux/gpio/consumer.h>
+#include <linux/of_device.h>
 #include <asm/unaligned.h>
 
-#define MAX_TOUCHES             2
+#define ILI210X_TOUCHES         2
+#define ILI251X_TOUCHES         10
 #define DEFAULT_POLL_PERIOD     20
 
 /* Touchscreen commands */
@@ -33,17 +35,25 @@ struct firmware_version {
         u8 minor;
 } __packed;
 
+enum ili2xxx_model {
+        MODEL_ILI210X,
+        MODEL_ILI251X,
+};
+
 struct ili210x {
         struct i2c_client *client;
         struct input_dev *input;
         unsigned int poll_period;
         struct delayed_work dwork;
         struct gpio_desc *reset_gpio;
+        enum ili2xxx_model model;
+        unsigned int max_touches;
 };
 
 static int ili210x_read_reg(struct i2c_client *client, u8 reg, void *buf,
                             size_t len)
 {
+        struct ili210x *priv = i2c_get_clientdata(client);
         struct i2c_msg msg[2] = {
                 {
                         .addr   = client->addr,
@@ -59,7 +69,38 @@ static int ili210x_read_reg(struct i2c_client *client, u8 reg, void *buf,
                 }
         };
 
-        if (i2c_transfer(client->adapter, msg, 2) != 2) {
+        if (priv->model == MODEL_ILI251X) {
+                if (i2c_transfer(client->adapter, msg, 1) != 1) {
+                        dev_err(&client->dev, "i2c transfer failed\n");
+                        return -EIO;
+                }
+
+                usleep_range(5000, 5500);
+
+                if (i2c_transfer(client->adapter, msg + 1, 1) != 1) {
+                        dev_err(&client->dev, "i2c transfer failed\n");
+                        return -EIO;
+                }
+        } else {
+                if (i2c_transfer(client->adapter, msg, 2) != 2) {
+                        dev_err(&client->dev, "i2c transfer failed\n");
+                        return -EIO;
+                }
+        }
+
+        return 0;
+}
+
+static int ili210x_read(struct i2c_client *client, void *buf, size_t len)
+{
+        struct i2c_msg msg = {
+                .addr   = client->addr,
+                .flags  = I2C_M_RD,
+                .len    = len,
+                .buf    = buf,
+        };
+
+        if (i2c_transfer(client->adapter, &msg, 1) != 1) {
                 dev_err(&client->dev, "i2c transfer failed\n");
                 return -EIO;
         }
@@ -71,7 +112,7 @@ static bool ili210x_touchdata_to_coords(struct ili210x *priv, u8 *touchdata,
                                         unsigned int finger,
                                         unsigned int *x, unsigned int *y)
 {
-        if (finger >= MAX_TOUCHES)
+        if (finger >= ILI210X_TOUCHES)
                 return false;
 
         if (touchdata[0] & BIT(finger))
@@ -83,17 +124,43 @@ static bool ili210x_touchdata_to_coords(struct ili210x *priv, u8 *touchdata,
         return true;
 }
 
+static bool ili251x_touchdata_to_coords(struct ili210x *priv, u8 *touchdata,
+                                        unsigned int finger,
+                                        unsigned int *x, unsigned int *y)
+{
+        if (finger >= ILI251X_TOUCHES)
+                return false;
+
+        *x = get_unaligned_be16(touchdata + 1 + (finger * 5) + 0);
+        if (!(*x & BIT(15)))    /* Touch indication */
+                return false;
+
+        *x &= 0x3fff;
+        *y = get_unaligned_be16(touchdata + 1 + (finger * 5) + 2);
+
+        return true;
+}
+
 static bool ili210x_report_events(struct ili210x *priv, u8 *touchdata)
 {
         struct input_dev *input = priv->input;
         int i;
-        bool touch;
-        unsigned int x, y;
+        bool contact = false, touch = false;
+        unsigned int x = 0, y = 0;
 
-        for (i = 0; i < MAX_TOUCHES; i++) {
+        for (i = 0; i < priv->max_touches; i++) {
                 input_mt_slot(input, i);
 
-                touch = ili210x_touchdata_to_coords(priv, touchdata, i, &x, &y);
+                if (priv->model == MODEL_ILI210X) {
+                        touch = ili210x_touchdata_to_coords(priv, touchdata,
+                                                            i, &x, &y);
+                } else if (priv->model == MODEL_ILI251X) {
+                        touch = ili251x_touchdata_to_coords(priv, touchdata,
+                                                            i, &x, &y);
+                        if (touch)
+                                contact = true;
+                }
+
                 input_mt_report_slot_state(input, MT_TOOL_FINGER, touch);
                 if (touch) {
                         input_report_abs(input, ABS_MT_POSITION_X, x);
@@ -104,7 +171,10 @@ static bool ili210x_report_events(struct ili210x *priv, u8 *touchdata)
         input_mt_report_pointer_emulation(input, false);
         input_sync(input);
 
-        return touchdata[0] & 0xf3;
+        if (priv->model == MODEL_ILI210X)
+                contact = touchdata[0] & 0xf3;
+
+        return contact;
 }
 
 static void ili210x_work(struct work_struct *work)
@@ -112,12 +182,20 @@ static void ili210x_work(struct work_struct *work)
         struct ili210x *priv = container_of(work, struct ili210x,
                                             dwork.work);
         struct i2c_client *client = priv->client;
-        u8 touchdata[1 + 4 * MAX_TOUCHES];
+        u8 touchdata[64] = { 0 };
         bool touch;
-        int error;
+        int error = -EINVAL;
+
+        if (priv->model == MODEL_ILI210X) {
+                error = ili210x_read_reg(client, REG_TOUCHDATA,
+                                         touchdata, sizeof(touchdata));
+        } else if (priv->model == MODEL_ILI251X) {
+                error = ili210x_read_reg(client, REG_TOUCHDATA,
+                                         touchdata, 31);
+                if (!error && touchdata[0] == 2)
+                        error = ili210x_read(client, &touchdata[31], 20);
+        }
 
-        error = ili210x_read_reg(client, REG_TOUCHDATA,
-                                 touchdata, sizeof(touchdata));
         if (error) {
                 dev_err(&client->dev,
                         "Unable to get touchdata, err = %d\n", error);
@@ -198,9 +276,12 @@ static int ili210x_i2c_probe(struct i2c_client *client,
         struct input_dev *input;
         struct panel_info panel;
         struct firmware_version firmware;
+        enum ili2xxx_model model;
         int xmax, ymax;
         int error;
 
+        model = (enum ili2xxx_model)id->driver_data;
+
         dev_dbg(dev, "Probing for ILI210X I2C Touschreen driver");
 
         if (client->irq <= 0) {
@@ -236,6 +317,11 @@ static int ili210x_i2c_probe(struct i2c_client *client,
         priv->poll_period = DEFAULT_POLL_PERIOD;
         INIT_DELAYED_WORK(&priv->dwork, ili210x_work);
         priv->reset_gpio = reset_gpio;
+        priv->model = model;
+        if (model == MODEL_ILI210X)
+                priv->max_touches = ILI210X_TOUCHES;
+        if (model == MODEL_ILI251X)
+                priv->max_touches = ILI251X_TOUCHES;
 
         i2c_set_clientdata(client, priv);
 
@@ -274,7 +360,7 @@ static int ili210x_i2c_probe(struct i2c_client *client,
         input_set_abs_params(input, ABS_Y, 0, ymax, 0, 0);
 
         /* Multi touch */
-        input_mt_init_slots(input, MAX_TOUCHES, 0);
+        input_mt_init_slots(input, priv->max_touches, 0);
         input_set_abs_params(input, ABS_MT_POSITION_X, 0, xmax, 0, 0);
         input_set_abs_params(input, ABS_MT_POSITION_Y, 0, ymax, 0, 0);
 
@@ -347,13 +433,15 @@ static SIMPLE_DEV_PM_OPS(ili210x_i2c_pm,
                          ili210x_i2c_suspend, ili210x_i2c_resume);
 
 static const struct i2c_device_id ili210x_i2c_id[] = {
-        { "ili210x", 0 },
+        { "ili210x", MODEL_ILI210X },
+        { "ili251x", MODEL_ILI251X },
         { }
 };
 MODULE_DEVICE_TABLE(i2c, ili210x_i2c_id);
 
 static const struct of_device_id ili210x_dt_ids[] = {
-        { .compatible = "ilitek,ili210x", },
+        { .compatible = "ilitek,ili210x", .data = (void *)MODEL_ILI210X },
+        { .compatible = "ilitek,ili251x", .data = (void *)MODEL_ILI251X },
         { },
 };
 MODULE_DEVICE_TABLE(of, ili210x_dt_ids);