input: ti_am33x_tsc: Add DT support

This patch adds DT support to touch driver. It also provides a binding
document which is used by the MFD and IIO part of the device.
This patch also renames steps_to_configure to coordinate_readouts
because the original name misleads the purpose of the variable.

Signed-off-by: Pantelis Antoniou <panto@antoniou-consulting.com>
Signed-off-by: Patil, Rachna <rachna@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

diff --git a/Documentation/devicetree/bindings/input/touchscreen/ti-tsc-adc.txt b/Documentation/devicetree/bindings/input/touchscreen/ti-tsc-adc.txt
new file mode 100644 (file)
index 0000000..491c97b
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/touchscreen/ti-tsc-adc.txt
@@ -0,0 +1,44 @@
+* TI - TSC ADC (Touschscreen and analog digital converter)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Required properties:
+- child "tsc"
+       ti,wires: Wires refer to application modes i.e. 4/5/8 wire touchscreen
+                 support on the platform.
+       ti,x-plate-resistance: X plate resistance
+       ti,coordiante-readouts: The sequencer supports a total of 16
+                               programmable steps each step is used to
+                               read a single coordinate. A single
+                                readout is enough but multiple reads can
+                               increase the quality.
+                               A value of 5 means, 5 reads for X, 5 for
+                               Y and 2 for Z (always). This utilises 12
+                               of the 16 software steps available. The
+                               remaining 4 can be used by the ADC.
+       ti,wire-config: Different boards could have a different order for
+                       connecting wires on touchscreen. We need to provide an
+                       8 bit number where in the 1st four bits represent the
+                       analog lines and the next 4 bits represent positive/
+                       negative terminal on that input line. Notations to
+                       represent the input lines and terminals resoectively
+                       is as follows:
+                       AIN0 = 0, AIN1 = 1 and so on till AIN7 = 7.
+                       XP  = 0, XN = 1, YP = 2, YN = 3.
+- child "adc"
+       ti,adc-channels: List of analog inputs available for ADC.
+                        AIN0 = 0, AIN1 = 1 and so on till AIN7 = 7.
+
+Example:
+       tscadc: tscadc@44e0d000 {
+               compatible = "ti,am3359-tscadc";
+               tsc {
+                       ti,wires = <4>;
+                       ti,x-plate-resistance = <200>;
+                       ti,coordiante-readouts = <5>;
+                       ti,wire-config = <0x00 0x11 0x22 0x33>;
+               };
+
+               adc {
+                       ti,adc-channels = <4 5 6 7>;
+               };
+       }

diff --git a/drivers/input/touchscreen/ti_am335x_tsc.c b/drivers/input/touchscreen/ti_am335x_tsc.c
index 7b7de60..449c0fb 100644 (file)
--- a/drivers/input/touchscreen/ti_am335x_tsc.c
+++ b/drivers/input/touchscreen/ti_am335x_tsc.c
@@ -26,6 +26,8 @@
 #include <linux/io.h>
 #include <linux/input/ti_am335x_tsc.h>
 #include <linux/delay.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
 
 #include <linux/mfd/ti_am335x_tscadc.h>
 
@@ -47,7 +49,7 @@ struct titsc {
        unsigned int            wires;
        unsigned int            x_plate_resistance;
        bool                    pen_down;
-       int                     steps_to_configure;
+       int                     coordinate_readouts;
        u32                     config_inp[4];
        u32                     bit_xp, bit_xn, bit_yp, bit_yn;
        u32                     inp_xp, inp_xn, inp_yp, inp_yn;
@@ -123,7 +125,7 @@ static void titsc_step_config(struct titsc *ts_dev)
        int i, total_steps;
 
        /* Configure the Step registers */
-       total_steps = 2 * ts_dev->steps_to_configure;
+       total_steps = 2 * ts_dev->coordinate_readouts;
 
        config = STEPCONFIG_MODE_HWSYNC |
                        STEPCONFIG_AVG_16 | ts_dev->bit_xp;
@@ -141,7 +143,7 @@ static void titsc_step_config(struct titsc *ts_dev)
                break;
        }
 
-       for (i = 1; i <= ts_dev->steps_to_configure; i++) {
+       for (i = 1; i <= ts_dev->coordinate_readouts; i++) {
                titsc_writel(ts_dev, REG_STEPCONFIG(i), config);
                titsc_writel(ts_dev, REG_STEPDELAY(i), STEPCONFIG_OPENDLY);
        }
@@ -163,7 +165,7 @@ static void titsc_step_config(struct titsc *ts_dev)
                break;
        }
 
-       for (i = (ts_dev->steps_to_configure + 1); i <= total_steps; i++) {
+       for (i = (ts_dev->coordinate_readouts + 1); i <= total_steps; i++) {
                titsc_writel(ts_dev, REG_STEPCONFIG(i), config);
                titsc_writel(ts_dev, REG_STEPDELAY(i), STEPCONFIG_OPENDLY);
        }
@@ -218,7 +220,7 @@ static void titsc_read_coordinates(struct titsc *ts_dev,
                read = titsc_readl(ts_dev, REG_FIFO0);
                channel = read & 0xf0000;
                channel = channel >> 0x10;
-               if ((channel >= 0) && (channel < ts_dev->steps_to_configure)) {
+               if ((channel >= 0) && (channel < ts_dev->coordinate_readouts)) {
                        read &= 0xfff;
                        diff = abs(read - prev_val_x);
                        if (diff < prev_diff_x) {
@@ -231,8 +233,8 @@ static void titsc_read_coordinates(struct titsc *ts_dev,
                read = titsc_readl(ts_dev, REG_FIFO1);
                channel = read & 0xf0000;
                channel = channel >> 0x10;
-               if ((channel >= ts_dev->steps_to_configure) &&
-                       (channel < (2 * ts_dev->steps_to_configure - 1))) {
+               if ((channel >= ts_dev->coordinate_readouts) &&
+                       (channel < (2 * ts_dev->coordinate_readouts - 1))) {
                        read &= 0xfff;
                        diff = abs(read - prev_val_y);
                        if (diff < prev_diff_y) {
@@ -310,6 +312,59 @@ static irqreturn_t titsc_irq(int irq, void *dev)
        return IRQ_HANDLED;
 }
 
+static int titsc_parse_dt(struct platform_device *pdev,
+                                       struct titsc *ts_dev)
+{
+       struct device_node *node = pdev->dev.of_node;
+       int err;
+
+       if (!node)
+               return -EINVAL;
+
+       err = of_property_read_u32(node, "ti,wires", &ts_dev->wires);
+       if (err < 0)
+               return err;
+       switch (ts_dev->wires) {
+       case 4:
+       case 5:
+       case 8:
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       err = of_property_read_u32(node, "ti,x-plate-resistance",
+                       &ts_dev->x_plate_resistance);
+       if (err < 0)
+               return err;
+
+       err = of_property_read_u32(node, "ti,coordiante-readouts",
+                       &ts_dev->coordinate_readouts);
+       if (err < 0)
+               return err;
+
+       return of_property_read_u32_array(node, "ti,wire-config",
+                       ts_dev->config_inp, ARRAY_SIZE(ts_dev->config_inp));
+}
+
+static int titsc_parse_pdata(struct ti_tscadc_dev *tscadc_dev,
+                                       struct titsc *ts_dev)
+{
+       struct mfd_tscadc_board *pdata = tscadc_dev->dev->platform_data;
+
+       if (!pdata)
+               return -EINVAL;
+
+       ts_dev->wires = pdata->tsc_init->wires;
+       ts_dev->x_plate_resistance =
+               pdata->tsc_init->x_plate_resistance;
+       ts_dev->steps_to_configure =
+               pdata->tsc_init->steps_to_configure;
+       memcpy(ts_dev->config_inp, pdata->tsc_init->wire_config,
+               sizeof(pdata->tsc_init->wire_config));
+       return 0;
+}
+
 /*
  * The functions for inserting/removing driver as a module.
  */
@@ -319,16 +374,8 @@ static int titsc_probe(struct platform_device *pdev)
        struct titsc *ts_dev;
        struct input_dev *input_dev;
        struct ti_tscadc_dev *tscadc_dev = ti_tscadc_dev_get(pdev);
-       struct mfd_tscadc_board *pdata;
        int err;
 
-       pdata = tscadc_dev->dev->platform_data;
-
-       if (!pdata) {
-               dev_err(&pdev->dev, "Could not find platform data\n");
-               return -EINVAL;
-       }
-
        /* Allocate memory for device */
        ts_dev = kzalloc(sizeof(struct titsc), GFP_KERNEL);
        input_dev = input_allocate_device();
@@ -342,11 +389,16 @@ static int titsc_probe(struct platform_device *pdev)
        ts_dev->mfd_tscadc = tscadc_dev;
        ts_dev->input = input_dev;
        ts_dev->irq = tscadc_dev->irq;
-       ts_dev->wires = pdata->tsc_init->wires;
-       ts_dev->x_plate_resistance = pdata->tsc_init->x_plate_resistance;
-       ts_dev->steps_to_configure = pdata->tsc_init->steps_to_configure;
-       memcpy(ts_dev->config_inp, pdata->tsc_init->wire_config,
-                       sizeof(pdata->tsc_init->wire_config));
+
+       if (tscadc_dev->dev->platform_data)
+               err = titsc_parse_pdata(tscadc_dev, ts_dev);
+       else
+               err = titsc_parse_dt(pdev, ts_dev);
+
+       if (err) {
+               dev_err(&pdev->dev, "Could not find valid DT data.\n");
+               goto err_free_mem;
+       }
 
        err = request_irq(ts_dev->irq, titsc_irq,
                          0, pdev->dev.driver->name, ts_dev);
@@ -362,7 +414,7 @@ static int titsc_probe(struct platform_device *pdev)
                goto err_free_irq;
        }
        titsc_step_config(ts_dev);
-       titsc_writel(ts_dev, REG_FIFO0THR, ts_dev->steps_to_configure);
+       titsc_writel(ts_dev, REG_FIFO0THR, ts_dev->coordinate_readouts);
 
        input_dev->name = "ti-tsc";
        input_dev->dev.parent = &pdev->dev;
@@ -398,7 +450,7 @@ static int titsc_remove(struct platform_device *pdev)
        free_irq(ts_dev->irq, ts_dev);
 
        /* total steps followed by the enable mask */
-       steps = 2 * ts_dev->steps_to_configure + 2;
+       steps = 2 * ts_dev->coordinate_readouts + 2;
        steps = (1 << steps) - 1;
        am335x_tsc_se_clr(ts_dev->mfd_tscadc, steps);
 
@@ -439,7 +491,7 @@ static int titsc_resume(struct device *dev)
        }
        titsc_step_config(ts_dev);
        titsc_writel(ts_dev, REG_FIFO0THR,
-                       ts_dev->steps_to_configure);
+                       ts_dev->coordinate_readouts);
        return 0;
 }
 
@@ -452,6 +504,12 @@ static const struct dev_pm_ops titsc_pm_ops = {
 #define TITSC_PM_OPS NULL
 #endif
 
+static const struct of_device_id ti_tsc_dt_ids[] = {
+       { .compatible = "ti,am3359-tsc", },
+       { }
+};
+MODULE_DEVICE_TABLE(of, ti_tsc_dt_ids);
+
 static struct platform_driver ti_tsc_driver = {
        .probe  = titsc_probe,
        .remove = titsc_remove,
@@ -459,6 +517,7 @@ static struct platform_driver ti_tsc_driver = {
                .name   = "tsc",
                .owner  = THIS_MODULE,
                .pm     = TITSC_PM_OPS,
+               .of_match_table = of_match_ptr(ti_tsc_dt_ids),
        },
 };
 module_platform_driver(ti_tsc_driver);

diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c
index 90ccfc0..f509766 100644 (file)
--- a/drivers/mfd/ti_am335x_tscadc.c
+++ b/drivers/mfd/ti_am335x_tscadc.c
@@ -203,6 +203,7 @@ static      int ti_tscadc_probe(struct platform_device *pdev)
        /* TSC Cell */
        cell = &tscadc->cells[TSC_CELL];
        cell->name = "tsc";
+       cell->of_compatible = "ti,am3359-tsc";
        cell->platform_data = &tscadc;
        cell->pdata_size = sizeof(tscadc);